Orthopedic Tumor Surgery MCQs: OITE & AAOS Prep Part 33

Orthopedic Surgery Board Review MCQs: AAOS Master Bank Part 33

Orthopedic Tumor Surgery Board Review MCQs: OITE & AAOS Master Bank Part 33

Comprehensive 100-Question Exam

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Question 1

An 18-year-old man has had an enlarging mass in his hand for the past 3 months. Radiographs, an MRI scan, and biopsy specimens are shown in Figures 54a through 54d. What is the most likely diagnosis?

Explanation

DISCUSSION: Also known as Nora’s lesion, BPOP is a benign osteocartilaginous tumor that almost always occurs in the hands and feet; one occurrence each in the femur and tibia has been reported. Although local recurrence is common after excision, metastases have not been reported.
REFERENCES: Abramovici L, Steiner GC: Bizarre parosteal osteochondromatous proliferation (Nora’s lesion): A retrospective study of 12 cases, 2 arising in long bones. Hum Pathol 2002;33:1205-1210.
Nora FE, Dahlin DC, Beabout JW: Bizarre parosteal osteochondromatous proliferations of the hands and feet. Am J Surg Pathol 1983;7:245-250.

Question 2

A 55-year-old man has had a mass in his right thigh for the past 2 months. An MRI scan and biopsy specimens are shown in Figures 55a through 55c. What is the most likely diagnosis?

Explanation

DISCUSSION: The histology shows extraskeletal myxoid chondrosarcoma, characterized by abundant blue myxoid matrix with cords and nests of small tumor cells. Treatment consists of wide resection. Despite the name, hyaline cartilage is not a common component of these tumors. Adult rhabdomyosarcoma and malignant fibrous histiocytoma are highly pleomorphic sarcomas often containing multinucleated giant cells. Myxoid liposarcoma contains a prominent capillary network and lipoblasts. Myxoma is less cellular than extraskeletal myxoid chondrosarcoma and does not have a cord-like arrangement of tumor cells.
REFERENCE: Kawaguchi S, Wada T, Nagoya S, Ikeda T, Isu K, Yamashiro K, et al: Extraskeletal myxoid chondrosarcoma. Cancer 2003;97:1285-1292.

Question 3

Figures 56a through 56c show the radiograph, CT scan, and biopsy specimen of a 44-year-old man who underwent chemotherapy and radiation therapy for lymphoma of the distal femur 20 years ago. His current problem is most likely related to

Explanation

DISCUSSION: The patient has changes consistent with radiation therapy to the femur, including osteopenia and an aggressive appearing neoplasm. The tumor is most likely a radiation-induced sarcoma. This is more likely than recurrent lymphoma at this late date. It is not related to steroid use or a primary lung tumor.
REFERENCES: Mirra J (ed): Bone Tumors: Clinical, Radiologic and Pathologic Correlations. Philadelphia, PA, Lea and Febiger, 1989, p 353.
Huvos A, Woodard H, Cahan W, et al: Postradiation osteogenic sarcoma of bone and soft tissue. A clinical pathologic study of 66 Patients. Cancer 1985;55:1244.

Question 4

What is the most common reason an individual with a malignant soft-tissue tumor in the extremities seeks medical attention?

Explanation

DISCUSSION: Unlike malignant bone tumors, malignant soft-tissue tumors usually are asymptomatic and present with the presence of a mass. Malignant soft-tissue tumors enlarge by centrifugal growth, creating a mass while compressing surrounding tissue. Symptoms may develop as the result of direct compression on neurovascular structures as the tumor enlarges. This is especially true in the pelvis where the tumor can enlarge appreciably without being noticed. However, in the extremities, the tumor is most often apparent before neurologic symptoms develop. An asymptomatic mass is not necessarily benign; therefore, biopsy should not be delayed. It is uncommon for a malignant soft-tissue mass to be discovered incidentally. Soft-tissue tumors are not typically apparent on radiographs; they are best identified with MRI.
REFERENCES: Brouns F, Stas M, De Wever I: Delay in diagnosis of soft tissue sarcomas. Eur J Surg Oncol 2003;29:440-445.
Rougraff B: The diagnosis and management of soft tissue sarcomas of the extremities in the adult. Curr Probl Cancer 1999;23:1-50.
Sim FH, Frassica FJ, Frassica DA: Soft-tissue tumors: Diagnosis, evaluation, and management. J Am Acad Orthop Surg 1994;2:202-211.

Question 5

Exostoses in which of the following anatomic locations is the most likely to undergo malignant transformation in a patient with multiple hereditary exostosis (MHE)?

Explanation

DISCUSSION: Although osteochondromas can occur in almost every bone in patients with MHE, proximally located lesions are more likely to undergo malignant transformation. Annual radiographs of the shoulder girdles and pelvis are indicated in patients with MHE. Any enlarging osteochondromas are a concern as possible malignancies.
REFERENCES: Peterson HA: Multiple hereditary osteochondromata. Clin Orthop 1989;239:222.
McCornack EB: The surgical management of hereditary multiple exostosis. Orthop Rev 1981;10:57.

Question 6

Initial management of a pathologic fracture of the humerus secondary to a unicameral bone cyst should include

Explanation

DISCUSSION: Most pathologic humeral fractures secondary to a unicameral bone cyst are minimally displaced and should be immobilized and allowed to heal. Persistent and/or progressive lesions may require treatment. Various treatments of unicameral bone cysts have been described. Acceptable treatment options include curettage and bone grafting, intralesional steroid injection, and percutaneous grafting with bone graft substitutes. MRI is not indicated when the diagnosis of unicameral bone cyst is known.
REFERENCES: Wilkins RM: Unicameral bone cysts. J Am Acad Orthop Surg 2000;8:217-224.
Bensahel H, Jehanno P, Desgrippes Y, Pennecot GF: Solitary bone cyst: Controversies and treatment. J Pediatr Orthop B 1998;7:257-261.

Question 7

An 11-year-old child has Ewing’s sarcoma of the femoral diaphysis with a small soft-tissue mass. Staging studies show no evidence of metastases. Treatment should consist of

Explanation

DISCUSSION: The use of chemotherapy has dramatically improved survival rates of patients with Ewing’s sarcoma. Local disease is best handled with wide resection to decrease local recurrence and to avoid the complications of radiation therapy (ie, secondary sarcomas). Radiation therapy alone is reserved for unresectable lesions or poor surgical margins. Amputation generally is not necessary.
REFERENCES: Toni A, Neff JR, Sudanese A, et al: The role of surgical therapy in patients with non-metastatic Ewing’s sarcoma of the limbs. Clin Orthop 1991;286:225.
Picci P, Rougraff BT, Bacci G, et al: Prognostic significance of histopathologic response to chemotherapy in non-metastatic Ewing’s sarcoma of the extremities. J Clin Oncol 1993;11:1763.
Gibbs CP Jr, Weber K, Scarborough MT: Malignant Bone Tumors. Instr Course Lect 2002;51:413-428.
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Question 8

A 65-year-old man with ankylosing spondylitis sustains an extension injury to his cervical spine. Two days later, a progressive neurologic deficit develops at the C6 level. An MRI scan is shown in Figure 1. What is the most likely diagnosis?

Explanation

DISCUSSION: It is common for patients with ankylosing spondylitis to sustain extension-type fractures, typically near the cervicothoracic junction. These fractures can be minimally displaced, making them difficult to diagnose. In addition, the vertebral bodies are vascular and their canals are relatively enclosed, making them vulnerable to epidural bleeding. The MRI scan shows an epidural hematoma posteriorly compressing the cord.
REFERENCES: Bohlman HH: Acute fractures and dislocations of the cervical spine. J Bone Joint Surg Am 1979;61:1119-1142.
Weinstein PR, Karpman RR, Gall EP, et al: Spinal cord injury, spine fracture and spinal stenosis in ankylosing spondylitis. J Neurosurg 1982;57:609-616.
Johnson T, Steinbach L (eds): Essentials of Musculoskeletal Imaging. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2003, p 44.

Question 9

What are the most common portals for arthroscopic surgery of the ankle?

Explanation

DISCUSSION: The most commonly used portals are the anterolateral, anteromedial, and posterolateral portals. They have been shown to be the safest areas for portal placement, allowing no penetration of neurovascular structures. All the other portals involve placing another structure at risk. The anterocentral portal is close to the deep peroneal nerve and anterior tibular artery. The trans-Achilles portal is not recommended because of its limited utility and potential to injure the Achilles tendon. The posteromedial portal is too close to the posterotibial artery and nerve, the flexor hallucis longus and flexor digitorum longus tendons, and the branches of the calcaneal nerve.
REFERENCES: Stetson WB, Ferkel RD: Ankle arthroscopy: I. Technique and complications.

J Am Acad Orthop Surg 1996;4:17-23.
Ferkel RD: Diagnostic arthroscopic examination, in Ferkel RD, Whipple TL (eds): Arthroscopic Surgery: The Foot and Ankle. Philadelphia, PA, Lippincott-Raven, 1996, pp 103-118.

Question 10

A patient who underwent primary total hip arthroplasty 7 years ago that resulted in excellent pain relief and a normal gait now reports pain and a limp. Postoperative and current AP radiographs are shown in Figures 2a and 2b. What is the most likely cause of the pathology seen?

Explanation

DISCUSSION: Osteolysis in the trochanteric bed can result in weakening of the bone and fracture. Nonsurgical management will provide reasonable clinical and radiographic results in patients with limited fracture displacement.
REFERENCES: Claus MC, Hopper RH, Engh CA: Fractures of the greater trochanter induced by osteolysis with the anatomic medullary locking prosthesis. J Arthroplasty 2002;17:706-712.
Heekin RD, Engh CA, Herzwurm MF: Fractures through cystic lesions of the greater trochanter: A cause of late pain after cementless total hip arthroplasty. J Arthroplasty 1996;11:757-760.

Question 11

The safest surgical approach to the insertion of the tibial posterior cruciate ligament uses the interval between which of the following muscles?

Explanation

DISCUSSION: Burks and Schaffer described an approach to the tibial insertion of the posterior cruciate ligament that uses the interval between the semimembranosus and the medial gastrocnemius. The medial gastrocnemius muscle is retracted laterally and protects the neurovascular bundle. This approach is used to repair an avulsion of the posterior cruciate ligament tibial attachment or for performing a posterior cruciate ligament tibial

inlay reconstruction.
REFERENCES: Berg EE: Posterior cruciate ligament tibial inlay reconstruction. Arthroscopy 1995;8:95-99.
Burks RT, Schaffer JJ: A simplified approach to the tibial attachment of the posterior cruciate ligament. Clin Orthop 1990;254:216-219.

Question 12

A 50-year-old man with no history of trauma reports new-onset back pain after doing some yard work the previous day. He reports pain radiating down his leg posteriorly and into the first dorsal web space of his foot. MRI scans are shown in Figures 3a through 3c. What nerve root is affected?

Explanation

DISCUSSION: The MRI scans clearly show an extruded L4-5 disk that is affecting the L5 nerve root on the left side. In addition, the L5 nerve root has a cutaneous distribution in the first dorsal web space. S1 affects the lateral foot. L4 affects the medial calf.
REFERENCE: An HS: Principles and Techniques of Spine Surgery. Baltimore, MD,

Williams and Wilkins, 1998, pp 98-100.

Question 13

A 19-year-old wrestler has numbness along the radial aspect of the forearm after undergoing an open Bankart repair through an anterior deltopectoral approach. Motor weakness would be expected along with what other finding?

Explanation

DISCUSSION: The musculocutaneous nerve may be injured by retracting the conjoined tendon medially. This nerve enters the coracobrachialis 5 cm distal to its origin. Its sensory distribution is the radial forearm, and its motor supply is to the biceps and brachialis.
REFERENCES: Bach BR, O’Brien SJ, Warren RF, et al: An unusual neurologic complication of the Bristow procedure. J Bone Joint Surg Am 1988;70:458-460.
McIlveen SJ, Duralde XA: Isolated nerve injuries about the shoulder, in Bigliani LU (ed): Complications of Shoulder Surgery. Baltimore, MD, Williams and Wilkins, 1993, pp 214-239.

Question 14

A 19-year-old man has had intermittent progressive knee pain with ambulation and pain at night following a rodeo accident 4 weeks ago. Figures 4a through 4e show the radiographs, a bone scan, CT scan, and T2-weighted MRI scan. What is the most likely diagnosis?

Explanation

DISCUSSION: The imaging studies reveal a predominantly blastic lesion in the distal femur with posterolateral periosteal changes. The bone scan shows increased uptake in the distal femur, beyond that expected with radiography. Cross-sectional imaging confirms the presence of a soft-tissue mass extending from the lateral aspect of the femur, with diffuse intramedullary signal changes. This aggressive presentation, particularly in this location and in a patient of this age, is most consistent with osteosarcoma. The mineralization in the soft tissue strongly suggests neoplasm, not the reactive bony changes seen in an infectious process.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 175-186.
Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 3800-3833.

Question 15

Figures 5a and 5b show the radiographs of an active 52-year-old man who has increasing knee pain and progressive varus deformity after undergoing total knee arthroplasty 7 years ago. Examination reveals a small effusion, but he has good motion and stability. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs show narrowing of the medial joint space, which indicates polyethylene wear and progressive varus alignment. Wear particles incite osteolytic lesions like the one seen on the lateral radiograph.
REFERENCES: O’Rourke MR, Callaghan JJ, Goetz DG, et al: Osteolysis associated with a cemented modular posterior-cruciate-substituting total knee design. J Bone Joint Surg Am 2002;84:1362-1371.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 529-530.

Question 16

Which of the following best describes the course of the median nerve at the elbow?

Explanation

DISCUSSION: The median nerve courses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, and deep to the superficial head of the pronator teres muscle. The median nerve lies within the interval between the flexor digitorum superficialis muscle and the flexor digitorium muscle as it progresses toward the wrist.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.
Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System. Part 1, Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy, 1991, vol 8,

pp 46-47.

Question 17

A 62-year-old woman with soft-tissue calcifications and telangiectasia has severe pain in the left index, middle, ring, and little fingers. History reveals that she does not smoke. The clinical history and arteriogram shown in Figure 6 are consistent with which of the following conditions?

Explanation

DISCUSSION: The arteriogram shows generalized disease of all vascular structures. Even though the image was obtained following an infusion of nitroglycerin, little flow is present to the fingers. Based on the history of soft-tissue calcifications and telangiectasia, the most likely diagnosis is CREST (chondrocalcinosis, Raynaud’s phenomenon, esophageal dysmotility, sclerodactyly and telangiectasias). The arteriogram reveals Raynaud’s phenomenon or the “R” component of CREST. Buerger’s disease, or thromboangiitis obliterans, is strongly associated with a history of smoking. Hypothenar hammer syndrome involves repetitive trauma to the ulnar artery at the wrist, resulting in well-defined filling defects in the superficial palmar arch of the hand. Although not well visualized in this patient, the superficial arch is narrowed, showing no evidence of aneurysmal dilation.
REFERENCES: Koman LA, Ruch DS, Patterson Smith B, et al: Vascular disorders, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, vol 2, pp 2254-2302.
Miller LM, Morgan RF: Vasospastic disorders: Etiology, recognition, and treatment. Hand Clin 1993;9:171-187.

Question 18

During excision of a Baker cyst, the base or stalk is usually found between the

Explanation

DISCUSSION: Although there are several bursae in the posterior portion of the knee, the most prevalent one with a connection to the knee joint is the one in the interval between the semimembranosus and the medial head of the gastrocnemius muscle. The popliteus muscle and posterior cruciate ligament, the posterior cruciate ligament and lateral gastrocnemius muscle, and the medial gastrocnemius muscle and posterior cruciate ligament are all too lateral and uncommon. The semitendinosus and medial head of the gastrocnemius muscles do not come in contact in the posterior aspect of the knee.
REFERENCES: Resnick D: Diagnosis of Bone and Joint Disorders, ed 3. Philadelphia, PA,

WB Saunders, 1995, p 379.
Justis EJ Jr: Nontraumatic disorders, in Crenshaw AH (ed): Campbell’s Operative Orthopaedics, ed 7. Philadelphia, PA, Lippincott, 1987, vol 3, p 2257.

Question 19

A direct lateral (Hardinge) approach is used during total hip arthroplasty. The structure labeled A in Figure 7 is the

Explanation

DISCUSSION: The superior gluteal nerve is located approximately 7.82 cm above the tip of the greater trochanter as it courses through the gluteus medius. This anatomic consideration is relevant during a Hardinge approach to the hip, where excessive proximal dissection or retraction could result in nerve injury. A split of the gluteus medius of no more than 4 cm above the greater trochanter is considered safe.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, pp 333-335.
Ramesh M, O’Byrne JM, McCarthy N, et al: Damage to the superior gluteal nerve after the Hardinge approach to the hip. J Bone Joint Surg Br 1996;78:903-906.

Question 20

The dorsal digital cutaneous nerve of the great toe shown in Figure 8 is a branch of what nerve?

Explanation

DISCUSSION: The dorsal digital cutaneous nerve of the great toe is a branch of the medial branch of the superficial peroneal nerve. The deep peroneal nerve supplies the first web space.
REFERENCES: McMinn RMH, Hutchings RT, Logan BM: Color Atlas of Foot and Ankle Anatomy. Weert, Netherlands, Wolfe Medical Publications, 1982, p 50.
Gray H: Anatomy of the Human Body. Philadelphia, PA, Lea & Febiger, 2000, pp 963, 966.

Question 21

In hip arthroplasty, the location of the medial femoral circumflex artery is best described as

Explanation

DISCUSSION: The obturator artery lies closest to the transverse acetabular ligament. The femoral artery is closest to the anterior rim of the acetabulum. No named vessel lies within the substance of the gluteus minimus or superior to the piriformis tendon. The medial femoral circumflex artery lies medial or deep to the quadratus femoris muscle.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach, ed 1. Philadelphia, PA, JB Lippincott, 1984, Figure 7-53, p 346.
Callaghan JJ, Rosenberg AG, Rubash HE: The Adult Hip. Philadelphia, PA, Lippincott-Raven, 1998, p 705.

Question 22

A 47-year-old man has acute right shoulder pain after falling off a ladder. The MRI scan shown in Figure 9 reveals

Explanation

DISCUSSION: The MRI scan reveals a full-thickness rotator cuff tear with retraction and increased signal in the subacromial space indicating joint fluid.
REFERENCES: Herzog RJ: Magnetic resonance imaging of the shoulder. Instr Course Lect 1998;47:3-20.
Iannotti JP, Zlatkin MB, Esterhai JL, et al: Magnetic resonance imaging of the shoulder: Sensitivity, specificity, and predictive value. J Bone Joint Surg Am 1991;73:17-29.

Question 23

The oblique radiograph of the foot and the CT scan shown in Figures 10a and 10b show a patient whose symptoms have failed to respond to rest and non-steroidal anti-inflammatory drugs. What is the best course of action?

Explanation

DISCUSSION: The radiograph and MRI scan show elongation and fragmentation of the os peroneum. Although casting, orthoses, and steroid injection may relieve symptoms, excision of the os peroneum and primary repair when necessary, with or without tenodesis of the peroneus longus to the peroneus brevis, have been shown to produce excellent results.
REFERENCES: Haddad SL: Disorders of tendons: Peroneal tendon dysfunction, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999,

pp 812-817.
MacDonald BD, Wertheimer SJ: Bilateral os peroneum fractures: Comparison of conservative and surgical treatment and outcomes. J Foot Ankle Surg 1997;36:220-225.

Question 24

What is the typical MRI signal intensity of bone marrow affected by acute osteomyelitis?

Explanation

DISCUSSION: The classic MRI findings of osteomyelitis are a decrease in the normally high signal intensity of marrow on T₁-weighted images and normal or increased signal intensity on T₂-weighted images. This is the result of replacement of marrow fat by inflammatory cells and edema, which causes lower signal intensity than fat on T₁-weighted images and higher signal intensity than fat on T₂-weighted images. The addition of gadolinium to a T₁-weighted sequence reveals increased signal intensity in the hyperemic marrow.
REFERENCES: Unger E, Moldofsky P, Gatenby R, et al: Diagnosis of osteomyelitis by MR imaging. Am J Roentgenol 1988;150:605-610.
Dormans JP, Drummond DS: Pediatric hematogenous osteomyelitis: New trends in presentation, diagnosis and treatment. J Am Acad Orthop Surg 1994;2:333-341.
Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2002, vol 1, pp 150-163.

Question 25

Based on the appearance of the imaging studies shown in Figures 11a through 11c, what structure has most likely been injured?

Explanation

DISCUSSION: The radiographs reveal marked lateral subluxation of the patella in a patient who has recurrent patellar instability. The medial patellofemoral ligament is the main restraint to lateral subluxation of the patella.
REFERENCES: Boden BP, Pearsall AW: Patellofemoral instability: Evaluation and management. J Am Acad Orthop Surg 1997;5:47-57.
Desio SM, Burks RT, Bachus KN: Soft tissue restraints to lateral patellar translation in the human knee. Am J Sports Med 1998;26:59-65.

Question 26

In the anterior forearm approach to the distal radius (Henry approach), the radial artery is located between what two structures?

Explanation

DISCUSSION: The standard approach to the volar aspect of the distal radius is the Henry approach. Following incision of the skin and subcutaneous tissues, the forearm fascia is incised. The radial artery and venae comitantes lie in the interval between the tendons of the flexor carpi radialis muscle and the brachioradialis muscle. This interval is developed, and the radial artery and veins are retracted in a radial direction.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.
Henry A: Extensile Exposure, ed 3. Edinburgh, UK, Churchill Livingstone, 1995, pp 100-107.

Question 27

Following a radial nerve neurapraxia at or above the elbow, return of muscle function can be expected to start at the brachioradialis and return along which of the following progressions?

Explanation

DISCUSSION: Following a radial nerve neurapraxia above the elbow, muscle recovery can be expected in a predictable pattern. Although variations will occur, the return of function or reinnervation usually occurs in the following order: brachioradialis, extensor carpi radialis longus, supinator, extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum comminus, extensor digiti minimi, extensor indicis proprious, extensor pollicis longus, abductor pollicis longus, and extensor pollicis brevis.
REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System. Part 1, Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ,

Ciba-Geigy, 1991, vol 8, p 53.
Hollinshead WH: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA,

Harper and Row, 1982, vol 3, pp 428-429.

Question 28

To preserve blood supply to the fractured bone seen in Figures 12a and 12b, care should be taken when exposing which of the following areas?

Explanation

DISCUSSION: The blood supply to the adult capitellum and lateral trochlea comes from posterior vessels arising from the radial recurrent, radial collateral, and interosseous recurrent arteries. These arteries penetrate the distal humerus posterior and superior to the capitellum.
REFERENCE: Yamaguchi K, Sweet FA, Bindra R, et al: The extraosseous and intraosseous arterial anatomy of the adult elbow. J Bone Joint Surg Am 1997;79:1653-1662.

Question 29

An axial T 1 -weighted MRI scan of the pelvis is shown in Figure 13. The arrow is pointing to what muscle?

Explanation

DISCUSSION: The obturator internus muscle originates from the internal pelvic wall and passes laterally through the lesser sciatic foramen, banking around the ischium below the sacrospinous ligament before inserting on the medial aspect of the greater trochanter.
REFERENCES: Higuchi T: Normal anatomy and magnetic resonance appearance of the pelvis, in Takahashi HE, Morita T, Hotta T, Ogose A (eds): Operative Treatment of Pelvic Tumors. Tokyo, Japan, Springer-Verlag, 2003, pp 4-21.
Berquist TH: Pelvis, hips and thigh, in Berquist TH (ed): MRI of the Musculoskeletal System,

ed 4. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 210-238.

Question 30

Which of the following radiographic views best depicts a Hill-Sachs defect?

Explanation

DISCUSSION: The Stryker notch view best shows this type of defect. An outlet view helps evaluate acromial shape, a true AP shows joint space narrowing, a serendipity view evaluates the sternoclavicular joint, and a Zanca view helps evaluate the acromioclavicular joint. An internal rotation AP may also depict a Hill-Sachs defect.
REFERENCE: Rockwood CA, et al: X-ray evaluation of shoulder problems, in Rockwood CA, Matsen FA (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, vol 1, pp 178-207.

Question 31

What structure provides the major blood supply to the humeral head?

Explanation

DISCUSSION: The ascending branch of the anterior circumflex humeral artery provides

the major blood supply to the humeral head. The posterior circumflex humeral artery

supplies a much smaller portion of the proximal humerus. The nutrient humeral artery is the main blood supply for the humeral shaft. The thoracoacromial artery is primarily a muscular branch. The rotator cuff insertions contribute some blood supply to the tuberosities but not a major contribution.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.
Cushner MA, Friedman RJ: Osteonecrosis of the humeral head. J Am Acad Orthop Surg 1997;5:339-346.

Question 32

Figure 14 shows an intra-articular gadolinium-enhanced MRI scan of a 52-year-old woman who has stopped playing tennis because of pain in her left shoulder while serving. What is the most likely diagnosis?

Explanation

DISCUSSION: The MRI scan shows increased signal intensity along the deep fibers of the supraspinatus near its insertion. This is typical of tendinosis and a probable partial-thickness rotator cuff tear.
REFERENCES: Herzog RJ: Magnetic resonance imaging of the shoulder. Instr Course Lect 1998;47:3-20.
Iannotti JP, Zlatkin MB, Esterhai JL, et al: Magnetic resonance imaging of the shoulder: Sensitivity, specificity, and predictive value. J Bone Joint Surg Am 1991;73:17-29.

Question 33

To adequately expose the volar plate of the proximal interphalangeal joint of the finger, which of following pulleys is typically incised?

Explanation

DISCUSSION: Full exposure of the volar plate of the proximal interphalangeal joint of the finger is best accomplished by incision of the distal C1, A3, and proximal C2 pulleys; followed by gentle retraction of the flexor digitorum superficialis and profundus tendons. Sacrifice of the A3 pulley, although associated with some biomechanic disadvantage, can be tolerated without causing functionally limiting bowstringing of the flexor tendon. Sacrifice of even a portion of the A2 or A4 pulleys can decrease the biomechanic leverage provided by the flexor tendon sheath, leading to bowstringing of the flexor tendons.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 176-186.
Strickland J: Flexor tendon-acute injuries, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, vol 2,

pp 1853-1855.
Lin GT, Amadio PC, An KN, et al: Functional anatomy of the human digital flexor pulley system. J Hand Surg Am 1989;14:949-956.

Question 34

A 42-year-old patient has had a fever and low back pain for several days. Laboratory studies show an elevated erythrocyte sedimentation rate and a WBC count of 9,500 mm3 with 75% neutrophils. A CT scan is shown in Figure 15. Examination will most likely reveal what other findings?

Explanation

DISCUSSION: The CT scan reveals a left-sided psoas abscess. Irritation of the saphenous division of the femoral nerve can cause paresthesias along the medial aspect of the knee. Pain is usually improved with hip flexion.
REFERENCES: Cellier C, Gendre JP, Cosnes J, et al: Psoas abscess complication Crohn’s disease. Gastroenterol Clin Biol 1992;16:235-238.
Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, pp 470-471, 506.

Question 35

Based on the diagram shown in Figure 16, what muscle derives its innervation from the nerve identified by the letter “A”?

Explanation

DISCUSSION: The nerve labeled A is the axillary nerve, a branch from the posterior cord. The posterior cord innervates the subscapularis, latissimus dorsi, teres major and minor, deltoid, triceps, anconeus, brachioradialis, and extensors of the forearm. The axillary nerve innervates the teres minor and deltoid. The pectoralis minor is innervated by the medial cord. The supraspinatus and the subclavius are innervated by the superior trunk. The brachialis is innervated by the lateral cord.
REFERENCES: Moore K: Anatomy, ed 3. Philadelphia, PA, Williams and Wilkins, 1992.
Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, pp 400, 405, 407, 450.

Question 36

In performing an opening wedge high tibial osteotomy at the tibial tubercle, the osteotome extends 5 mm posteriorly and centrally out of the bone as shown in Figures 17a and 17b. What is the first structure it enters?

Explanation

DISCUSSION: The major risk of performing a high tibial osteotomy is neurovascular injury. The new version of the high tibial osteotomy makes a transverse osteotomy at the level of the tibial tubercle. The osteotome is protected by the oblique belly of the popliteus muscle. The popliteal artery and vein and tibial nerve all lie posterior to the muscle. The soleus muscle originates below this level.
REFERENCES: Clement CD: Anatomy: A Regional Atlas of Human Anatomy, ed 3.

Baltimore, MD, Munich, Germany, Urban and Schwarzberg, 1987, Figure 422.
Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, plate 480.

Question 37

The arrow in the axial T 1 -weighted MRI scan shown in Figure 18 is pointing to which of the following structures?

Explanation

DISCUSSION: The arrow is pointing to the ulnar nerve within Guyon’s canal. Guyon’s canal is approximately 4 cm long, beginning at the proximal extent of the transverse carpal ligament and ending at the aponeurotic arch of the hypothenar muscles. Many structures comprise the boundaries of Guyon’s canal. The floor, for example, consists of the transverse carpal ligament, the pisohamate and pisometacarpal ligaments, and the opponens digiti minimi. Within Guyon’s canal, the ulnar nerve bifurcates into the superficial and deep branches, with the deep branch of the ulnar nerve persisting distal to the canal. The ulnar artery is immediately adjacent and radial to the ulnar nerve. The median nerve is visualized within the carpal tunnel. The radial artery is on the radial side of the wrist. The hook of the hamate is clearly seen in the figure, orienting the observer to the ulnar side of the wrist.
REFERENCES: Goss MS, Gelberman RH: The anatomy of the distal ulnar tunnel. Clin Orthop 1985;196:238-247.
Denman EE: The anatomy of the space of Guyon. Hand 1978;10:69-76.

Question 38

Osteonecrosis of the femoral head after intramedullary nailing in children is thought to be the result of injury to the

Explanation

DISCUSSION: All of these are possible explanations for the development of osteonecrosis following intramedullary nailing in children. However, the lateral ascending cervical artery, which supplies the epiphysis, is much more vulnerable to injury in children because it lies in the trochanteric fossa.
REFERENCES: Buckley SL: Current trends in the treatment of femoral shaft fractures in children and adolescents. Clin Orthop 1997;338:60-73.
Rockwood CA, Wilkins KE, Beaty JH: Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, p 1214.

Question 39

The illustration shown in Figure 19 shows a Chamberlain line. What is the most likely diagnosis?

Explanation

DISCUSSION: Basilar invagination is best defined as vertical or compressive instability at the occiput-C1 joint. Such invaginations most commonly occur in patients with rheumatoid arthritis but also can occur secondary to trauma or tumor. A Chamberlain line is used as a method to determine basilar invagination. The odontoid tip should not be more than 5 mm above a Chamberlain line.
REFERENCES: Wiesel SW, Rothman RH: Occipito-atlantal hypermobility.

Spine 1979;4:187-191.
Clark CR: The Cervical Spine, ed 3. Philadelphia, PA, Lippincott-Raven, 1998, pp 50-51.

Question 40

Figures 20a and 20b show the sagittal and coronal T1-weighted MRI scans of a patient’s left knee. Abnormal findings include

Explanation

DISCUSSION: The MRI scans show meniscal tissue extending across the entire lateral compartment, revealing a discoid lateral meniscus. The increased signal within the lateral meniscal tissue indicates a tear. Discoid lateral menisci are congenital variants that often present with mechanical symptoms in adolescents. The other structures in the knee are normal.
REFERENCES: Ahn JH, Shim JS, Hwang CH, et al: Discoid lateral meniscus in children: Clinical manifestations and morphology. J Pediatr Orthop 2001;21:812-816.
Andrish JT: Meniscal injuries in children and adolescents: Diagnosis and management.

J Am Acad Orthop Surg 1996;4:231-237.

Question 41

An ulnar nerve palsy at the level of the wrist is typically associated with deficits in the palmaris brevis, the hypothenar muscles, and what other groups of muscles?

Explanation

DISCUSSION: The intrinsic muscles innervated by the ulnar nerve include the palmaris brevis, hypothenar muscles, all of the interossei, adductor pollicis, and the deep head of the flexor pollicis brevis. The superficial head of the flexor pollicis brevis is innervated by the

median nerve.
REFERENCES: Goldfarb CA, Stern PJ: Low ulnar nerve palsy. JASSH 2003;3:14-26.
Omer G: Ulnar nerve palsy, in Green DP, Hotchkiss R, Pederson W (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, Churchill Livingstone, 1999, pp 1526-1541.

Question 42

Figures 21a and 21b show the radiographs of a 22-year-old man who has had progressive pain and swelling about the knee for the past 6 weeks. Examination reveals limited range of motion and fullness about the knee. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs reveal a destructive lesion in the metaphysis of the distal femur with periosteal changes and an associated soft-tissue mass with subtle mineralization. This suggests an aggressive malignant process. In this age group, the most likely diagnosis is osteosarcoma. Giant cell tumor, which usually is in a more subchondral location, is not typically so aggressive. Aneurysmal bone cyst is usually more geographic, with a well-marginated reactive rim.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 175-186.
Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 3800-3833.

Question 43

The anterolateral (Watson-Jones) approach to the hip exploits the intermuscular interval between the

Explanation

DISCUSSION: The Watson-Jones approach to the hip uses the intermuscular interval between the gluteus medius and the tensor fascia lata. This is not a true internervous plane, as both muscles are supplied by the superior gluteal nerve.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, pp 316-332.
Crenshaw AH (ed): Campbell’s Operative Orthopedics, ed 7. St Louis, MO, CV Mosby, 1987,

p 63.

Question 44

An 8-month-old infant has an infection of the fingertip as shown in Figure 22. If neglected, the anticipated path of ascending infection is the fingertip, the flexor sheath, and the

Explanation

DISCUSSION: The flexor sheaths are in continuity with the deep spaces of the hand. The flexor sheaths of the thumb and little finger communicate with the radial and ulnar bursae, respectively, and these two bursae commonly communicate. The central digits do not communicate as readily with deep spaces of the hand but if flexor tendon sheath infection of the index, long, and right fingers is neglected, the potential exists for rupture into the deep midpalmar spaces.
REFERENCES: Peimer CA (ed): Surgery of the Hand and Upper Extremity: Acute and Chronic Sepsis. New York, NY, Mcgraw Hill, 1996, pp 1735-1741.
Trumble TE (ed): Hand Surgery Update 3: Hand, Elbow and Shoulder. Rosemont, IL, American Society for Surgery of the Hand, 2003, pp 445-446.

Question 45

A 24-year-old man has had pain in the left knee for the past several months. He reports that initially the pain was associated with weight-bearing activities, but it has now become more constant. He denies any swelling but reports a lateral fullness at the tibial plateau. Figures 23a through 23e show radiographs, a bone scan, and T1- and T2-weighted MRI scans. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs reveal a lytic subchondral lesion that has a poorly defined margin and lacks mineralization. The bone scan confirms an active lesion that has central photopenia, producing the characteristic doughnut configuration. The MRI scans confirm the presence of a subchondral lesion that is modestly expansile at the lateral plateau and has low signal intensity on the T1-weighted image and a mixed high signal on the T2-weighted image. These features strongly suggest giant cell tumor of bone, more than 50% of which appear around the knee. Simple cyst is excluded by the MRI characteristics. Fibrous dysplasia is unlikely to be in a subchondral location and typically does not show this intensity of uptake on bone scan.
REFERENCES: Parsons TW: Benign bone tumors, in Fitzgerald RH, Kaufer H,

Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1027-1035.
Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 3939-3962.

Question 46

Figure 24 shows an axial MRI scan of the ankle. The arrowhead is pointing to what structure?

Explanation

DISCUSSION: The peroneus brevis is easily identified by its location behind the fibula and its distal muscle belly. Axial MRI images provide a reliable guide even when one of the peroneals is completely ruptured, subluxated out of the peroneal groove, or absent.
REFERENCES: Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. New York, NY, Lippincott, 1993, pp 234-235.
Sammarco GJ: Peroneus longus tendon tears: Acute and chronic. Foot Ankle Int

1995;16:245-253.

Question 47

During total hip arthroplasty, profuse bleeding is noted following predrilling for placement of an acetabular component screw. The drill most likely penetrated too deep in the

Explanation

DISCUSSION: The acetabular quadrants are defined by two lines: one drawn from the anterosuperior iliac spine to the posterior fovea, forming acetabular halves, and a second drawn perpendicular to the first at the midpoint of the acetabulum, forming four quadrants. The anterior quadrants should be avoided because improper screw placement may injure the external iliac artery and vein, as well as the obturator nerve, artery, and vein. These structures lie close to the pelvic bone, with little protective interposition of soft tissue.
REFERENCES: Wasielewski RC, Cooperstein LA, Kruger MP, et al: Acetabular anatomy and the transacetabular fixation of screws in total hip arthroplasty. J Bone Joint Surg Am 1990;72:501-508.
Keating EM, Ritter MA, Faris PM: Structures at risk from medially placed acetabular screws.

J Bone Joint Surg Am 1990;72:509-511.

Question 48

A posterolateral approach to the tibial plafond proceeds between what two muscles?

Explanation

DISCUSSION: A posterolateral approach to the posterior malleolus proceeds between the

lateral and deep posterior compartments. Distally, the peroneus brevis muscle lies most

medially within the lateral compartment, and the flexor hallucis longus lies most laterally

in the deep posterior compartment.
REFERENCES: Henry AK: Extensile Exposure, ed 2. Edinburgh, UK, Churchill Livingstone, 1973, pp 269-270.
Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, p 515.

Question 49

The brachialis muscle is innervated by what two nerves?

Explanation

DISCUSSION: The brachialis is innervated by two nerves: medially, the musculocutaneous nerve; laterally, the radial nerve. The muscle is split longitudinally to approach the humerus anteriorly.
REFERENCES: Henry AK: The distal part of the humerus and front of the forearm, in Henry AK (ed): Extensile Exposure, ed 2. Edinburgh, UK, Churchill Livingstone, 1973, pp 90-115.
King A, Johnston GH: A modification of Henry’s anterior approach to the humerus. J Shoulder Elbow Surg 1998;7:210-212.

Question 50

Figure 25 shows the CT scan of an adult patient who has neck pain following a motor vehicle accident. What is the most likely diagnosis?

Explanation

DISCUSSION: If the atlanto-dens interval is greater than 3 mm in an adult, a transverse ligament rupture usually is suspected. The atlanto-dens interval can be seen with CT or in lateral radiographs of the upper cervical spine. Transverse ligament rupture can occur as an isolated entity or in association with an odontoid or a Jefferson’s fracture. Patients with this type of injury usually require fusion.
REFERENCES: Dickman CA, Greene KA, Sonntag VK: Injuries involving the transverse atlantal ligament: Classification and treatment guidelines based upon experience with 39 injuries. Neurosurgery 1996;38:44-50.
Clark CR: The Cervical Spine, ed 3. Philadelphia, PA, Lippincott-Raven, 1998, pp 362-363.

Question 51

A 28-year-old female presents with a slow-growing, painful mass near her knee joint. MRI shows a soft tissue mass adjacent to the joint capsule. Biopsy reveals a biphasic pattern of spindle cells and epithelial cells. Which of the following translocations is most characteristic of this lesion?

Explanation

Synovial sarcoma is characterized by the t(X;18)(p11;q11) translocation, resulting in the SYT-SSX fusion gene. It commonly presents near joints in young adults and often exhibits a biphasic histology.

Question 52

A 14-year-old boy completes neoadjuvant chemotherapy for an osteosarcoma of the distal femur. He subsequently undergoes wide surgical resection. Which of the following findings on the resected specimen is the most important prognostic factor for his long-term survival?

Explanation

Tumor necrosis greater than 90% following neoadjuvant chemotherapy is the single most important prognostic indicator for overall survival in osteosarcoma patients. It reflects the tumor's sensitivity to the systemic treatment.

Question 53

A 62-year-old man presents with a destructive diaphyseal lesion in the right humerus and an impending pathologic fracture. Biopsy confirms metastatic renal cell carcinoma. Prior to prophylactic intramedullary nailing, what is the most appropriate next step in management?

Explanation

Metastatic renal cell carcinoma and thyroid carcinoma lesions are highly vascular. Preoperative angioembolization within 24 to 48 hours of surgery is critical to significantly reduce intraoperative blood loss.

Question 54

A 55-year-old woman is diagnosed with a grade II chondrosarcoma of the ilium. Staging studies show no evidence of metastatic disease. What is the most appropriate definitive management?

Explanation

Intermediate and high-grade chondrosarcomas are notoriously resistant to both chemotherapy and radiation therapy. The standard of care is wide surgical resection with negative margins.

Question 55

A 32-year-old man with a recurrent giant cell tumor of the distal radius is treated with denosumab prior to surgical resection. What is the mechanism of action of this medication?

Explanation

Denosumab is a monoclonal antibody that binds to RANKL, preventing it from binding to the RANK receptor on osteoclasts and osteoclast precursors. This inhibits osteoclast-mediated bone destruction, which is driven by the neoplastic stromal cells in giant cell tumors.

Question 56

A 40-year-old man presents with chronic hip pain. Radiographs reveal an epiphyseal lytic lesion in the proximal femur with central calcifications. Biopsy demonstrates sheets of cells with abundant clear cytoplasm and distinct boundaries mixed with areas of hyaline cartilage. What is the most likely diagnosis?

Explanation

Clear cell chondrosarcoma is a rare, low-grade malignant bone tumor that characteristically involves the epiphysis of long bones in middle-aged adults. It must be differentiated from chondroblastoma, which typically occurs in much younger patients with open physes.

Question 57

A 12-year-old boy presents with a diaphysial permeative lesion in the fibula with an associated "onion-skin" periosteal reaction. A core needle biopsy is performed. Which of the following immunohistochemical markers and translocations will most likely be positive?

Explanation

Ewing sarcoma typically presents with a permeative diaphyseal lesion and "onion-skinning". It is strongly positive for CD99 (MIC2) and is characterized by the t(11;22) translocation, forming the EWS-FLI1 fusion protein.

Question 58

A 16-year-old boy has night pain in his tibia relieved by NSAIDs. CT shows a 6 mm radiolucent nidus surrounded by sclerotic bone. Radiofrequency ablation (RFA) is planned. RFA is contraindicated if the lesion is located within what distance of a major motor nerve?

Explanation

Radiofrequency ablation is the treatment of choice for most osteoid osteomas. However, it is generally contraindicated if the nidus is located within 1 cm (10 mm) of a major nerve or the spinal cord to avoid thermal neural injury.

Question 59

A 68-year-old man presents with diffuse bone pain and a newly diagnosed pathologic fracture of the proximal humerus. Laboratory studies reveal hypercalcemia, anemia, and renal insufficiency. Serum protein electrophoresis shows an M-spike. Which of the following is the most definitive diagnostic test for his underlying condition?

Explanation

The patient's clinical picture is classic for multiple myeloma (CRAB criteria). A bone marrow biopsy demonstrating greater than 10% clonal plasma cells is required for definitive diagnosis.

Question 60

A 55-year-old man undergoes resection of a large, deep soft tissue mass in his posterior thigh. Pathology reveals a myxoid liposarcoma. Which of the following genetic translocations is characteristic of this tumor?

Explanation

Myxoid liposarcoma is characterized by the t(12;16) translocation, which results in the FUS-DDIT3 fusion gene. It frequently metastasizes to extrapulmonary sites, such as the spine and other bones.

Question 61

A 9-year-old boy sustains a minor fall and presents with arm pain. Radiographs reveal a pathologic fracture through a centrally located, cystic lesion in the proximal humerus with a "fallen leaf" sign. After the fracture heals, what is the initial preferred management to prevent recurrence?

Explanation

The presentation and "fallen leaf" sign are pathognomonic for a unicameral bone cyst (UBC). The initial treatment of choice after fracture healing is typically minimally invasive, utilizing corticosteroid or autologous bone marrow injections.

Question 62

A 30-year-old woman presents with a firm, painless mass in the anterior thigh. Biopsy demonstrates a proliferation of bland fibroblastic cells in a collagenous stroma with no atypia or necrosis. Beta-catenin staining is strongly positive. Which of the following is the most appropriate initial management?

Explanation

The pathology describes a desmoid tumor (aggressive fibromatosis), characterized by beta-catenin mutations. Current guidelines strongly favor initial observation (active surveillance) as many tumors spontaneously stabilize or regress.

Question 63

A 60-year-old man presents with chronic sacral pain and bowel/bladder dysfunction. Imaging shows a large, destructive, midline mass in the sacrum. Biopsy reveals physaliferous cells in a myxoid background. What is the most appropriate surgical approach for definitive treatment?

Explanation

Chordomas are chemoresistant and relatively radioresistant low-grade malignancies characterized by physaliferous cells. Wide en bloc resection with negative margins offers the best chance for local control and long-term survival.

Question 64

A 35-year-old man presents with anterior tibial pain. Radiographs show a multiloculated, eccentric, osteolytic lesion in the anterior tibial diaphysis. Histology shows nests of epithelial cells in a fibrous stroma. What is the recommended treatment?

Explanation

The clinical and histologic picture describes adamantinoma, a low-grade malignant bone tumor that almost exclusively occurs in the anterior tibial diaphysis. It is insensitive to radiation and chemotherapy, making wide surgical resection the treatment of choice.

Question 65

A 45-year-old patient with Neurofibromatosis type 1 (NF1) notices rapid enlargement and pain in a long-standing peripheral nerve mass. Biopsy reveals a high-grade spindle cell sarcoma. Which genetic alteration is most closely associated with the underlying syndrome leading to this tumor?

Explanation

Patients with NF1 have a mutation in the NF1 gene, leading to a loss of the tumor suppressor protein neurofibromin. They have a 5-10% lifetime risk of developing a Malignant Peripheral Nerve Sheath Tumor (MPNST), often from a pre-existing plexiform neurofibroma.

Question 66

A 72-year-old man with a long-standing history of Paget's disease of the pelvis presents with increasing pain and a rapidly enlarging mass in the right ilium. Radiographs show a new area of aggressive cortical destruction. What is the most likely diagnosis?

Explanation

Secondary osteosarcoma is a rare but highly lethal complication of Paget's disease, occurring in approximately 1% of patients. It presents with new-onset, severe pain and rapidly progressive bone destruction in an area of previously stable pagetic bone.

Question 67

Which of the following is a fundamental principle when performing a biopsy of a suspected malignant musculoskeletal tumor?

Explanation

Biopsy tracts are considered contaminated with tumor cells. A core principle of oncologic surgery is placing the biopsy incision longitudinally and in line with the planned definitive surgical incision so the entire tract can be excised en bloc.

Question 68

A 35-year-old woman presents with recurrent, bloody knee effusions and joint pain. MRI reveals a large, lobulated intra-articular mass with prominent "blooming" artifact on gradient-echo sequences. What is the primary pathophysiologic driver of this condition?

Explanation

The patient has diffuse tenosynovial giant cell tumor (formerly PVNS), characterized by a blooming artifact on MRI due to hemosiderin. The underlying pathogenesis involves a translocation leading to the overexpression of CSF1, which recruits the macrophages that form the tumor mass.

Question 69

A 60-year-old woman with breast cancer has a lytic metastasis in the peritrochanteric region of the femur. The lesion involves 50% of the cortex, and she reports moderate pain with weight-bearing. Using Mirels' criteria, what is her score and the recommended management?

Explanation

Mirels' criteria assess fracture risk based on site (lower extremity = 3), pain (moderate = 2), lesion type (lytic = 3), and size (1/3 to 2/3 cortex = 2), totaling 10. A score of 9 or higher warrants prophylactic internal fixation.

Question 70

A 25-year-old male presents with chronic knee pain. Imaging reveals a lytic lesion in the proximal tibial epiphysis. Biopsy shows chondroid matrix with cells containing abundant clear cytoplasm. Immunohistochemistry is positive for S-100. What is the most likely diagnosis?

Explanation

Clear cell chondrosarcoma is a low-grade malignant bone tumor that typically arises in the epiphysis of long bones in young adults. Histologically, it is characterized by cells with abundant clear cytoplasm and chondroid matrix, distinguishing it from chondroblastoma and giant cell tumors.

Question 71

A 12-year-old boy presents with thigh pain. Radiographs show a sunburst periosteal reaction in the distal femur. Biopsy confirms osteosarcoma. Following neoadjuvant chemotherapy, what is the most important prognostic factor for his overall survival?

Explanation

The most significant prognostic factor for overall survival in patients with osteosarcoma is the percentage of tumor necrosis following neoadjuvant chemotherapy. A necrosis rate of 90% or greater is considered a favorable histologic response.

Question 72

A 35-year-old male presents with a deep thigh mass. Biopsy reveals a biphasic spindle cell neoplasm. Molecular testing shows a t(X;18) translocation. Which of the following is the most likely diagnosis?

Explanation

Synovial sarcoma typically occurs in young adults as a deep soft tissue mass and often displays a biphasic histology. It is genetically characterized by the t(X;18) translocation, resulting in the SYT-SSX fusion gene.

Question 73

A 50-year-old female presents with a destructive sacral mass causing bowel and bladder dysfunction. Histology demonstrates lobules of cells with abundant vacuolated cytoplasm in a myxoid background. Which immunohistochemical marker is most specific for this diagnosis?

Explanation

The clinical scenario and presence of physaliferous cells describe a chordoma. Brachyury, a transcription factor involved in notochordal development, is a highly sensitive and specific immunohistochemical marker for chordoma.

Question 74

Denosumab is often utilized in the management of surgically unsalvageable or metastatic Giant Cell Tumor of bone. What is the specific mechanism of action of this medication?

Explanation

Denosumab is a monoclonal antibody that binds to RANKL, preventing it from activating the RANK receptor on osteoclast precursors. This inhibits the recruitment and action of osteoclast-like giant cells, halting the bone destruction characteristic of Giant Cell Tumor.

Question 75

A 60-year-old male presents with a pathologic fracture of the proximal humerus. Radiographs show a permeative lytic lesion. Biopsy reveals metastatic renal cell carcinoma. What is the most appropriate next step prior to operative stabilization?

Explanation

Metastatic renal cell carcinoma and thyroid carcinoma lesions are notoriously hypervascular. Preoperative angiographic embolization is highly recommended to significantly reduce intraoperative blood loss during surgical stabilization.

Question 76

A 15-year-old male presents with night pain in his tibia that is relieved by NSAIDs. Radiographs show a small radiolucent nidus surrounded by dense sclerotic bone. Which inflammatory mediator is found in high concentrations within the nidus?

Explanation

Osteoid osteomas secrete high levels of prostaglandins, specifically Prostaglandin E2, which causes the characteristic intense night pain. This is the mechanism by which NSAIDs provide dramatic pain relief.

Question 77

A 30-year-old male presents with an anterior tibial bowing deformity and an intracortical lytic lesion in the tibial diaphysis. Biopsy reveals a biphasic tumor with epithelial cells in a fibrous stroma. What is the recommended treatment?

Explanation

The clinical and histologic description is classic for adamantinoma, a low-grade malignant bone tumor predominantly affecting the tibial diaphysis. Treatment requires wide surgical resection, as the tumor does not respond well to chemotherapy or radiation.

Question 78

A 16-year-old girl presents with knee pain. Imaging reveals an eccentric, lytic lesion in the distal femoral epiphysis with fine calcifications. Biopsy demonstrates mononuclear cells, scattered osteoclast-like giant cells, and areas of chicken-wire calcification. What is the most likely diagnosis?

Explanation

Chondroblastoma is a benign cartilage tumor that almost exclusively occurs in the epiphysis of skeletally immature patients. Histology is characterized by mononuclear cells, giant cells, and intercellular chicken-wire calcification.

Question 79

A 14-year-old boy has a permeative lesion in the femoral diaphysis with an onion-skin periosteal reaction. Biopsy shows sheets of uniform small, blue, round cells. Which genetic translocation is most characteristic of this tumor?

Explanation

This describes Ewing sarcoma, characterized by small blue round cells and an onion-skin periosteal reaction. Over 90% of cases are associated with the t(11;22) translocation, creating the EWS-FLI1 fusion protein.

Question 80

A 70-year-old man with a history of Paget disease presents with new, severe pain and swelling in his thigh. Radiographs show cortical destruction and a soft tissue mass arising from a previously thickened, bowed femur. What is the most likely diagnosis?

Explanation

Malignant transformation in Paget disease occurs in about 1% of patients, usually manifesting as secondary osteosarcoma. It presents with new-onset pain and a destructive lesion, carrying a very poor prognosis.

Question 81

A 45-year-old woman presents with a deep intramuscular mass in her thigh. Biopsy reveals uniform round to oval cells in a myxoid stroma with a delicate, branching chicken-wire capillary network. This tumor is characterized by which of the following translocations?

Explanation

Myxoid liposarcoma features a distinct chicken-wire vascular pattern and lipoblasts in a myxoid background. It is genetically defined by the t(12;16) translocation, resulting in the FUS-DDIT3 fusion.

Question 82

A patient with multiple enchondromas and numerous soft-tissue hemangiomas is at the highest risk for developing which of the following complications?

Explanation

The presence of multiple enchondromas and soft-tissue hemangiomas indicates Maffucci syndrome. Patients with Maffucci syndrome have a nearly 100% lifetime risk of malignant transformation, most commonly to chondrosarcoma.

Question 83

A 20-year-old woman presents with an expansile, lytic lesion in the proximal humerus. MRI shows multiple fluid-fluid levels. Genetic testing of the biopsy tissue reveals a USP6 gene rearrangement. What is the most likely diagnosis?

Explanation

Aneurysmal bone cysts (ABCs) classically show fluid-fluid levels on MRI. Primary ABCs are driven by rearrangements of the USP6 gene, distinguishing them from secondary ABCs or telangiectatic osteosarcoma.

Question 84

A 30-year-old female presents with a painless, slow-growing mass in the posterior thigh. MRI shows a poorly circumscribed mass within the muscle. Biopsy reveals spindle cells with abundant collagen, lacking nuclear atypia. Immunohistochemistry shows nuclear beta-catenin expression. Which condition is most strongly associated with this tumor?

Explanation

The clinical and histologic findings are diagnostic of a desmoid tumor (aggressive fibromatosis), characterized by nuclear beta-catenin accumulation. These tumors are strongly associated with Familial Adenomatous Polyposis (FAP) and Gardner syndrome.

Question 85

A 65-year-old male presents with generalized bone pain and fatigue. Radiographs show multiple punched-out lytic lesions in the skull and long bones. A technetium-99m bone scan is negative in the areas of the lytic lesions. What is the most common laboratory abnormality associated with this condition?

Explanation

Multiple myeloma typically presents with punched-out lytic lesions that appear cold on a technetium bone scan due to lack of osteoblastic activity. Diagnosis is supported by an M-spike (monoclonal immunoglobulin) on serum or urine protein electrophoresis.

Question 86

A 28-year-old female presents with recurrent knee swelling and catching. MRI demonstrates a nodular intra-articular soft tissue mass with significant blooming artifact on gradient-echo sequences. What is the underlying pathogenesis of this condition?

Explanation

Pigmented villonodular synovitis (PVNS), now termed tenosynovial giant cell tumor (TGCT), exhibits blooming artifact on MRI due to hemosiderin. It is a neoplastic process driven by a translocation that causes overexpression of CSF1, recruiting inflammatory macrophages.

Question 87

A 10-year-old boy is diagnosed with alveolar rhabdomyosarcoma of the forearm. Which of the following genetic translocations is most characteristic of this specific subtype and confers a poorer prognosis compared to embryonal variants?

Explanation

Alveolar rhabdomyosarcoma is characterized by the t(2;13) translocation, yielding the PAX3-FOXO1 fusion gene. This molecular profile is associated with a significantly worse prognosis than embryonal rhabdomyosarcoma.

Question 88

A 25-year-old female presents with a painless, densely ossified mass attached to the posterior cortex of the distal femur. MRI shows no medullary involvement. Histology reveals mature bone trabeculae separated by a bland fibrous stroma. Amplification of which gene is characteristic of this lesion?

Explanation

The lesion is a parosteal osteosarcoma, a low-grade surface osteosarcoma typically found on the posterior distal femur. It is characterized molecularly by amplification of the MDM2 and CDK4 genes.

Question 89

A 55-year-old patient undergoes resection of a large, high-grade soft tissue sarcoma of the thigh. The pathology report notes microscopically positive margins (R1 resection) along a major neurovascular bundle that was deliberately preserved. What is the most appropriate next step in management to optimize local control?

Explanation

In cases of high-grade soft tissue sarcomas where major neurovascular structures are preserved (yielding a planned microscopic positive margin), postoperative adjuvant radiation therapy is indicated to achieve local control. It provides local recurrence rates comparable to radical resection or amputation.

Question 90

A 24-year-old woman presents with a slowly enlarging, painful mass in her plantar midfoot. Radiographs show a soft tissue mass with stippled calcifications. Biopsy reveals a biphasic spindle cell neoplasm. Which of the following cytogenetic abnormalities is most characteristic of this lesion?

Explanation

Synovial sarcoma is characterized by the t(X;18) translocation resulting in the SYT-SSX fusion gene. It often presents in young adults in the distal extremities (foot/hand) and frequently demonstrates calcification on plain radiographs.

Question 91

A 32-year-old woman presents with a large, lytic, eccentrically located lesion in the distal femur extending to the subchondral bone. Biopsy confirms Giant Cell Tumor (GCT) of bone. She is treated preoperatively with denosumab to downstage the tumor. What is the precise mechanism of action of this medication?

Explanation

Denosumab is a human monoclonal antibody that binds directly to RANK Ligand (RANKL). This prevents RANKL from binding to the RANK receptor on osteoclasts and their precursors, thereby halting osteoclastogenesis and bone destruction.

Question 92

A 45-year-old man presents with chronic hip pain. Radiographs reveal a lytic epiphyseal lesion in the proximal femur with central calcification. Histology shows cells with abundant clear cytoplasm and distinct boundaries mixed with areas of conventional chondrosarcoma. What is the most appropriate definitive management?

Explanation

Clear cell chondrosarcoma is a low-grade malignant bone tumor that uniquely occurs in the epiphysis, often mimicking chondroblastoma. Because it is a chondrosarcoma, it is inherently resistant to traditional chemotherapy and radiation, making wide surgical resection the standard of care.

Question 93

A 14-year-old boy undergoes neoadjuvant chemotherapy followed by limb-salvage surgery for classic high-grade osteosarcoma of the distal femur. Which of the following is the most important prognostic factor for his long-term overall survival?

Explanation

The percentage of tumor necrosis following neoadjuvant chemotherapy is the single most reliable prognostic indicator for overall survival in osteosarcoma patients. Greater than 90% necrosis indicates a good response and correlates with significantly higher survival rates.

Question 94

A 62-year-old man with a history of renal cell carcinoma presents with progressive severe right arm pain. Radiographs show a large destructive lytic lesion in the humeral diaphysis with impending fracture. What is the most critical step prior to proceeding with surgical stabilization?

Explanation

Metastatic renal cell carcinoma and thyroid carcinoma lesions are notoriously hypervascular. Preoperative selective arterial embolization should be performed within 24 to 48 hours prior to surgical fixation to minimize catastrophic intraoperative blood loss.

Question 95

A 58-year-old man presents with a painful mass in his proximal humerus. Radiographs show a lesion with intra-lesional pop-corn calcifications and an adjacent aggressive lytic component destroying the cortex. Biopsy reveals a low-grade cartilage tumor abruptly transitioning to a high-grade spindle cell sarcoma. What is the most likely diagnosis?

Explanation

Dedifferentiated chondrosarcoma is characterized by a bimorphic histologic appearance, with a distinct, abrupt transition between a low-grade chondroid lesion and a high-grade non-chondroid sarcoma. The radiographic appearance reflects this dual nature, showing a benign-appearing calcified area adjacent to an aggressive lytic zone.

Question 96

A 12-year-old boy presents with a permeative lytic lesion in the tibial diaphysis with an associated "onion skin" periosteal reaction. Biopsy shows sheets of small round blue cells that stain positive for CD99 and PAS, but negative for reticulin. Which of the following fusion genes is most likely present?

Explanation

The clinical, radiographic, and histologic profile confirms Ewing sarcoma, which typically stains strongly for CD99 (MIC2) and PAS. The most common genetic anomaly is the t(11;22) translocation, which yields the EWS-FLI1 fusion gene.

Question 97

A 28-year-old woman presents with a slow-growing, painless mass on the posterior aspect of her distal femur. Imaging shows a heavily ossified, lobulated mass attached to the posterior cortex by a broad stalk, with a cleavage plane visible between the tumor and the underlying bone. Amplification of which gene is characteristic of this lesion?

Explanation

Parosteal osteosarcoma is a low-grade surface osteosarcoma typically found on the posterior distal femur. It is characterized cytogenetically by ring chromosomes resulting in the amplification of the MDM2 and CDK4 genes.

Question 98

A 65-year-old man presents with severe back pain, anemia, and hypercalcemia. A skeletal survey reveals multiple punched-out lytic lesions in the skull and spine. Which of the following imaging modalities is most likely to yield false-negative results when evaluating his bone lesions?

Explanation

Technetium-99m bone scintigraphy relies on osteoblastic activity. Because multiple myeloma primarily stimulates osteoclast activity without a coupled osteoblast response, traditional bone scans are frequently negative ("cold") and are not reliable for staging.

Question 99

A 55-year-old man presents with progressive bowel and bladder dysfunction. An MRI of the sacrum reveals a destructive midline mass centered at S3. Biopsy shows lobules of vacuolated (physaliferous) cells with abundant mucoid stroma. Immunohistochemistry is positive for brachyury and cytokeratin. What is the most appropriate surgical management?

Explanation

The presence of physaliferous cells and positive brachyury staining confirms a sacral chordoma. Because chordomas are highly recurrent, locally aggressive, and largely chemoresistant, the standard of care is en bloc wide surgical resection with negative margins.

None

Detailed Chapters & Topics

Dive deeper into specialized chapters regarding orthopedic-board-review-oite-aaos-part-33

40 Chapters

Chapter 1 21 min

Orthopedic Board Review: Bone Tumors & Osteochondromas

Test your knowledge on bone tumors, focusing on osteochondromas, multiple hereditary exostoses, malignant transformatio…

Chapter 2 80 min

Essential Questions: Spinal Tumour Diagnosis & Treatment

Spine structured oral questions1: Spinal tumour CANDIDATE : The images show a destructive lesion in the vertebrae which…

Chapter 3 79 min

Orthopaedic Oncology Generic: Ace Tumor Staging for Oral Exams

Orthopaedic oncology Generic structured oral examination question 3: Staging EXAMINER : So what stage is this tumour? C…

Chapter 4 103 min

Orthopedic Board Prep: Master UICC Staging for Bone Sarcomas with MCQs

Ace your Orthopedic Board Prep with interactive MCQs on UICC staging for bone sarcomas. Test your knowledge, track scor…

Chapter 5 11 min

Sacral Tumor Surgery: Safeguarding Bowel & Bladder Control

BACKGROUND Tumors involving the sacrum mainly include primary and metastatic tumors. Metastatic tumors are more common …

Chapter 6 11 min

Treating Tumors of the Foot: Optimizing Amputation & Resection

Explore expert surgical strategies for treating malignant foot tumors. Learn why amputation often outperforms limb salv…

Chapter 7 17 min

Surgical Pelvic Resection: Gluteus Maximus Muscle & Nerve Preservation

Discover the complexities of surgical pelvic resection for bone sarcomas. Learn how to manage tumors while preserving v…

Chapter 8 12 min

Master the Principles of Biopsy: Your Guide to Accurate Tissue Diagnosis

Principles of biopsy 11 ‌ ‌ Needle biopsy of bone 11 ‌ Open biopsy of bone 14 ‌ Excision of benign bone tumour 16 Bone …

Chapter 9 30 min

Atypical Lipomatous Tumor (ALT) & Well-Differentiated Liposarcoma: Epidemiology, Genetics, & Surgical Management

Learn about Atypical Lipomatous Tumor (ALT) and Well-Differentiated Liposarcoma. Discover their epidemiology, genetics,…

Chapter 10 15 min

Sacral Chordoma: An Advanced Orthopedic Case Study on Diagnosis & Imaging

Read this advanced orthopedic case study of a 58-year-old male with sacral chordoma. Discover the signs of delayed diag…

Chapter 11 17 min

Elastofibroma Dorsi: Clinical Presentation, Imaging, and Diagnostic Pitfalls in a Geriatric Patient

Explore this clinical case study of Elastofibroma Dorsi in a 72-year-old male. Discover key symptoms, diagnostic pitfal…

Chapter 12 24 min

Ewing Sarcoma: Comprehensive Orthopedic Insights into Epidemiology, Surgical Anatomy & Biomechanics

Explore comprehensive orthopedic insights on Ewing sarcoma. Understand its epidemiology, clinical presentation, prognos…

Chapter 13 16 min

Grand Rounds: Giant Cell Tumor of Bone – A Detailed Diagnostic Case Study

Explore this diagnostic case study of a 28-year-old male presenting with a giant cell tumor of bone. Discover patient h…

Chapter 14 16 min

Knee Synovial Chondromatosis: A Detailed Clinical & Advanced Imaging Diagnostic Case Study

Dive into this complex orthopedic case study of primary knee synovial chondromatosis. Review patient history, advanced …

Chapter 15 14 min

Skeletal Langerhans Cell Histiocytosis: Orthopedic Diagnosis, Biomechanics & Management

Explore the orthopedic diagnosis and management of skeletal Langerhans Cell Histiocytosis. Learn to identify osteolytic…

Chapter 16 16 min

Chondrosarcoma Diagnosis: A Detailed Clinical & Imaging Case Study

Discover the clinical hallmarks of chondrosarcoma in this detailed case study. Follow a 58-year-old male's progression …

Chapter 17 17 min

Osteoblastoma of the Distal Femur: A Comprehensive Diagnostic Case Study

Explore a comprehensive diagnostic case study of a 22-year-old male presenting with progressive right knee pain and a d…

Chapter 18 14 min

Diffuse Tenosynovial Giant Cell Tumor (TGCT) of the Knee: Pathophysiology & Surgical Anatomy

Explore the pathophysiology and surgical anatomy of diffuse TGCT of the knee. Learn about its epidemiology, joint impac…

Chapter 19 20 min

Deep Posterior Thigh Liposarcoma: An Orthopedic Oncology Case Study & Diagnostic Approach

Read this orthopedic oncology case study of a 62-year-old male with a painless, enlarging posterior thigh mass diagnose…

Chapter 20 13 min

Proximal Humerus Cartilaginous Tumors: Navigating the Enchondroma-Chondrosarcoma Dilemma

Explore the clinical challenges of differentiating benign enchondromas from low-grade chondrosarcomas in proximal humer…

Chapter 21 17 min

Comprehensive Case Study: Ewing Sarcoma Diagnosis, Imaging, & Patient Presentation

Read this comprehensive Ewing sarcoma case study detailing the presentation of a 15-year-old male with nocturnal thigh …

Chapter 22 23 min

Adamantinoma of the Distal Tibia: A Detailed Orthopedic Case Study on Diagnosis

Read our detailed orthopedic case study on a 32-year-old male presenting with severe pain and swelling, leading to a di…

Chapter 23 15 min

Clinical Case Study: Distal Femoral Osteosarcoma Diagnosis & Management

Read a detailed clinical case study of a 16-year-old male presenting with severe nocturnal thigh pain, leading to a dis…

Chapter 24 16 min

Orthopedic Case Study: Diagnosing Pigmented Villonodular Synovitis (PVNS) of the Knee

Discover this orthopedic case study on diagnosing Pigmented Villonodular Synovitis (PVNS) of the knee in a male with ch…

Chapter 25 18 min

Myositis Ossificans: A Challenging Orthopedic Oncology Case & Diagnostic Pitfalls

Read this challenging orthopedic case study of myositis ossificans in a 28-year-old athlete. Learn about symptom progre…

Chapter 26 20 min

Clear Cell Sarcoma of the Foot & Ankle: A Comprehensive Orthopedic Guide

Explore our comprehensive orthopedic guide on Clear Cell Sarcoma of the foot and ankle. Learn about its epidemiology, d…

Chapter 27 20 min

Aggressive Distal Femur Osteolytic Lesion: An Orthopedic Oncology Case Study

Orthopedic case study: Aggressive osteolytic lesion, distal femur (45M). Covers presentation, exam, and imaging finding…

Chapter 28 11 min

of Musculoskeletal Tumors: Diagnostic and Surgical Strategies

A comprehensive, evidence-based guide for orthopedic surgeons on the diagnostic evaluation, staging, biopsy, and surgic…

Chapter 29 11 min

Chondrosarcoma: Comprehensive Diagnosis, Pathology, and Surgical Management

Learn about chondrosarcoma, a malignant bone tumor. Explore our comprehensive guide on its clinical presentation, patho…

Chapter 30 10 min

Principles of Orthopaedic Oncology: Limb Salvage and Surgical Margins

Explore orthopaedic oncology principles, focusing on the paradigm shift in sarcoma treatment and the complex decision b…

Chapter 31 11 min

Primary and Secondary Bone Lymphoma: A Comprehensive Surgical and Clinical Guide

Discover our comprehensive clinical guide to primary and secondary bone lymphoma. Learn about key symptoms, diagnosis, …

Chapter 32 11 min

Chondroblastoma: Comprehensive Pathology, Diagnosis, and Surgical Management

Explore the pathology, diagnosis, and surgical management of chondroblastoma. Discover symptoms and treatments for this…

Chapter 33 11 min

Benign & Nonneoplastic Bone Tumors: Surgical Management

Discover the diagnosis and surgical management of benign and nonneoplastic bone tumors. Learn about intraosseous lipoma…

Chapter 34 15 min

Cartilage Lesions: Comprehensive Surgical Management of Chondromas and Osteochondromas

Explore an evidence-based masterclass on the surgical management of cartilage lesions, focusing on benign chondromas an…

Chapter 35 12 min

Ewing Sarcoma: Comprehensive Pathology, Diagnosis, and Surgical Management

Master the complexities of Ewing sarcoma, an aggressive bone cancer. Explore our comprehensive guide on pathology, diag…

Chapter 36 11 min

Operative Management and Evaluation of Soft-Tissue Tumors

Master the clinical evaluation and operative management of soft-tissue tumors. Learn essential diagnostic steps to iden…

Chapter 37 20 min

Principles of Orthopedic Oncology: Biopsy, Limb Salvage, and Reconstruction

Masterclass on orthopedic oncology, detailing biopsy principles, limb salvage biomechanics, pelvic resections, and gian…

Chapter 38 11 min

Operative Management of Benign and Aggressive Bone Tumors: The Giant Cell Tumor Masterclass

Master the surgical management of Giant Cell Tumors of bone. Evidence-based guide covering extended curettage, adjuvant…

Chapter 39 11 min

Comprehensive Surgical Management of Benign Spinal Tumors

Master the diagnosis and surgical management of benign spinal tumors. Discover key epidemiology facts, age and location…

Chapter 40 61 min

ABOS Part I & OITE Orthopedic Review: AC Joint & Sarcoma MCQs | Part 22152

Prepare for your ABOS Part I and AAOS OITE exams with 20 advanced orthopedic MCQs. Master high-yield AC Joint and Sarco…

Back to All Master Guides

Medically Verified Content by

Prof. Dr. Mohammed Hutaif

Consultant Orthopedic & Spine Surgeon

Quick Medical Answer

Orthopedic Tumor Surgery Board Review MCQs: OITE & AAOS Master Bank Part 33

Detailed Chapters & Topics

Orthopedic Board Review: Bone Tumors & Osteochondromas

Essential Questions: Spinal Tumour Diagnosis & Treatment

Orthopaedic Oncology Generic: Ace Tumor Staging for Oral Exams

Orthopedic Board Prep: Master UICC Staging for Bone Sarcomas with MCQs

Sacral Tumor Surgery: Safeguarding Bowel & Bladder Control

Treating Tumors of the Foot: Optimizing Amputation & Resection

Surgical Pelvic Resection: Gluteus Maximus Muscle & Nerve Preservation

Master the Principles of Biopsy: Your Guide to Accurate Tissue Diagnosis

Atypical Lipomatous Tumor (ALT) & Well-Differentiated Liposarcoma: Epidemiology, Genetics, & Surgical Management

Sacral Chordoma: An Advanced Orthopedic Case Study on Diagnosis & Imaging

Elastofibroma Dorsi: Clinical Presentation, Imaging, and Diagnostic Pitfalls in a Geriatric Patient

Ewing Sarcoma: Comprehensive Orthopedic Insights into Epidemiology, Surgical Anatomy & Biomechanics

Grand Rounds: Giant Cell Tumor of Bone – A Detailed Diagnostic Case Study

Knee Synovial Chondromatosis: A Detailed Clinical & Advanced Imaging Diagnostic Case Study

Skeletal Langerhans Cell Histiocytosis: Orthopedic Diagnosis, Biomechanics & Management

Chondrosarcoma Diagnosis: A Detailed Clinical & Imaging Case Study

Osteoblastoma of the Distal Femur: A Comprehensive Diagnostic Case Study

Diffuse Tenosynovial Giant Cell Tumor (TGCT) of the Knee: Pathophysiology & Surgical Anatomy

Deep Posterior Thigh Liposarcoma: An Orthopedic Oncology Case Study & Diagnostic Approach

Proximal Humerus Cartilaginous Tumors: Navigating the Enchondroma-Chondrosarcoma Dilemma

Comprehensive Case Study: Ewing Sarcoma Diagnosis, Imaging, & Patient Presentation

Adamantinoma of the Distal Tibia: A Detailed Orthopedic Case Study on Diagnosis

Clinical Case Study: Distal Femoral Osteosarcoma Diagnosis & Management

Orthopedic Case Study: Diagnosing Pigmented Villonodular Synovitis (PVNS) of the Knee

Myositis Ossificans: A Challenging Orthopedic Oncology Case & Diagnostic Pitfalls

Clear Cell Sarcoma of the Foot & Ankle: A Comprehensive Orthopedic Guide

Aggressive Distal Femur Osteolytic Lesion: An Orthopedic Oncology Case Study

of Musculoskeletal Tumors: Diagnostic and Surgical Strategies

Chondrosarcoma: Comprehensive Diagnosis, Pathology, and Surgical Management

Principles of Orthopaedic Oncology: Limb Salvage and Surgical Margins

Primary and Secondary Bone Lymphoma: A Comprehensive Surgical and Clinical Guide

Chondroblastoma: Comprehensive Pathology, Diagnosis, and Surgical Management

Benign & Nonneoplastic Bone Tumors: Surgical Management

Cartilage Lesions: Comprehensive Surgical Management of Chondromas and Osteochondromas

Ewing Sarcoma: Comprehensive Pathology, Diagnosis, and Surgical Management

Operative Management and Evaluation of Soft-Tissue Tumors

Principles of Orthopedic Oncology: Biopsy, Limb Salvage, and Reconstruction

Operative Management of Benign and Aggressive Bone Tumors: The Giant Cell Tumor Masterclass

Comprehensive Surgical Management of Benign Spinal Tumors

ABOS Part I & OITE Orthopedic Review: AC Joint & Sarcoma MCQs | Part 22152

Guide Overview