Question 1

Which digit is most commonly affected by macrodactyly:

Explanation

The index finger is most frequently affected, although multiple digital enlargement is actually more commonly seen.

Question 2

Syndactyly is present in what percentage of patients with macrodactyly:

Explanation

The majority of patients (90%) present with unilateral macrodactyly, and men are more often affected than women. Macrodactyly is most frequently found in the index finger, followed by the long finger, thumb, ring, and little fingers. Typically, two digits are affected â most commonly the thumb and index or the index and long. Syndactyly may be present in 10% of patients with macrodactyly.

Question 3

Macrodactyly that is present at birth is termed:

Explanation

Barsky described macrodactyly as either static or progressive. Static macrodactyly is present at birth, and the affected digit grows larger as the child develops. In the progressive type of macrodactyly, growth begins soon after birth. This form of the disorder is more common than static macrodactyly.

Question 4

The most accepted theory for the cause of macrodactyly is:

Explanation

Some surgeons believe that macrodactyly is a variant of neurofibromatosis. Although macrodactyly is not an inherited anomaly, there are syndromes that may be associated with enlarged digits such as Proteus syndrome. Although numerous causes have been suggested, the most accepted theory was described by Inglis in 1950. He theorized that the abnormal nerves exert influence on the local tissues to stimulate growth.

Question 5

Syndromes that may be associated with macrodactyly include:

Explanation

Some surgeons believe that macrodactyly is a variant of neurofibromatosis. Although macrodactyly is not an inherited anomaly, there are syndromes that may be associated with enlarged digits such as Proteus syndrome. Theoretical causes for macrodactyly include a neural cause, a vascular cause, as well as a humoral mechanism. The most accepted theory is that abnormal nerves exert some influence on the local tissues to stimulate growth.7

Question 6

Macrodactyly affects:

Explanation

Although this is controversial, the majority of surgeons believe that macrodactyly affects bones, fat, and nerves.

Question 7

A 2-year-old child is brought to your office for evaluation of a "big hand." Upon examination, you notice that the child has mildly enlarged ring and small fingers. There is full range of motion without instability. After examination of the patient, you recommend:

Explanation

The child is not ready for surgery. Although surgery may coincide with the patient beginning school, this does not always occur. At this time, additional examination and testing are recommended.

Question 8

A 2-year-old child is brought to your office for evaluation of a "big hand." Upon examination, you notice that the child has mildly enlarged ring and small fingers. There is full range of motion without instability. The childâ s parents inform you that they would like you to amputate the affected digits as soon as possible. You should:

Explanation

Although amputation may be necessary in some patients with macrodactyly, it is too early in the course of this case to begin entertaining such a drastic measure. A debulking procedure is not recommended for a 2-year-old child. Radiation therapy is not an option in uncomplicated cases of macrodactyly. The surgeon must educate the parents about the disease process and order additional testing.

Question 9

You discover that a patient who you have been treating for macrodactyly has been followed by the Proteus Syndrome Foundation. Exhaustive work-up has been completed and radiographs of the hand reveal:

Explanation

In patients with macrodactyly, surgeons do not typically find enchondromas, especially not multiple enchondromas in the affected fingers. Enlargement of the bones is found in all dimensions â not only in the length and width. If the bones appear normal on radiograph, then they are not affected by macrodactyly.

Question 10

A 2-year-old child is brought to your office for evaluation of a "big hand." Upon examination, you notice that the child has mildly enlarged ring and small fingers. There is full range of motion without instability. After examination of the patient, you discuss the diagnosis of macrodactyly with the parents. The parents feel assured after your discussion of the disease process and your review of the radiographs. You should next see the patient:

Explanation

Patients with macrodactyly should be followed up yearly. Although the parents may be difficult, this is not a reason to stop seeing a patient. The other answers choices are incorrect because treatment would be too late.

Question 11

Which of the following is not a complication of macrodactyly surgery:

Explanation

Complications of macrodactyly surgery include poor healing of flaps secondary to devascularization or undue tension, nerve injury or decreased sensation, infection, stiffness, bony nonunion or malunion, and failure of the epiphysiodesis.

Question 12

Epiphysiodesis for macrodactyly should be performed at the following location:

Explanation

Treatment by epiphysiodesis for macrodactyly is ineffective if only single phalanges are treated. Therefore, treatment of the proximal phalanx, distal phalanx, or the middle phalanx alone is incorrect. The author prefers to perform epiphysiodesis only on the proximal and distal phalanges. The middle phalanx is not treated to preserve motion at the proximal interphalangeal joint.

Question 13

When ruptured, which portion of the scapholunate ligament leads to scaphoid-lunate diastasis:

Explanation

The dorsal section of the scapholunate ligament is the strongest portion, requiring 300 N of load for failure. The volar (150 N) and intermediate portions (25 N to 50 N) contribute less to overall stability.

Question 14

Which of the following radiographic views is not routinely used to diagnose scapholunate injury:

Explanation

The semisupination oblique view is used to visualize the pisiform and pisotriquetral joint. The PA oblique and lateral views are the primary films used to diagnose scapholunate instability. The clenched fist view is used as a provocative view to bring out dynamic instability.

Question 15

Which of the following treatments is not used for acute scapholunate ligament ruptures:

Explanation

Proximal row carpectomy is a salvage procedure for chronic instability with focal radioscaphoid arthritis. Open repair with sutures through bone tunnels, open repair with suture anchors, and arthroscopically assisted reduction and pinning have been used successfully in acute cases.

Question 16

Which of the following is considered indicative of a scaphoid-lunate ligament tear on posteroanterior radiograph:

Explanation

The VISI, DISI, and spilled tea cup signs are seen on lateral radiographs, whereas the Watson-Jones scaphoid shift test is a clinical sign. The classic pattern after scaphoid-lunate ligament injury is a DISI pattern as the lunate extends and the scaphoid flexes. The spilled tea cup sign is present in perilunate dislocations.

Question 17

The Terry Thomas sign, which is considered indicative of scaphoid-lunate ligament rupture, is best described as:

Explanation

The Terry Thomas sign refers to scapholunate diastases that may be apparent on posteroanterior radiographs of the wrist and is indicative of rupture if the diastases are larger than 3 mm. It is named after the famous comedian who had a gap between his front teeth.

Question 18

The most important requirement for a diagnostic magnetic resonance image (MRI) study in cases of scaphoid-lunate ligament injury is:

Explanation

MRI is not considered the technique of choice for the evaluation of the scaphoid-lunate ligament. Standard MRI coils are not adequate for the evaluation of the ligaments of the wrist. To maximize the yield from a wrist MRI, high-field strength and highresolution images must be obtained using dedicated wrist coils. Only with such dedicated coils can detailed information be derived regarding the continuity of the scapoid-lunate ligament. Physical examination and wrist arthroscopy remain the gold standards for the evaluation of a torn scaphoid-lunate ligament.

Question 19

In cases of subacute scaphoid-lunate ligament injury with no arthrosis, all of the following are acceptable options except:

Explanation

In cases of subacute scaphoid-lunate ligament injury without arthrosis, it is acceptable to attempt reconstruction with bone anchors, allograft ligament repair, capsulodesis, bone-ligament-bone autograft, and the RASL procedure with a Herbert screw. In the presence of localized arthritis, one might consider one of the limited wrist fusions such as scaphotrapeziotrapezoid fusion.

Question 20

Mallet finger injuries refer to:

Explanation

Mallet finger injuries may be associated with fractures of the bony tuft, fractures of the middle phalanx, flexor tendon injuries, and intrinsic tightness. However, mallet injuries refer to lack of continuity at the DIP joint.

Question 21

In mallet finger injuries, the distal phalanx posture is:

Explanation

The characteristic deformity is â droopingâ at the distal interphalangeal (DIP) joint. The DIP is flexed. It is not hyperextended, neutral, or deviated.

Question 22

Mallet finger injuries are typically:

Explanation

Mallet finger usually results from a blow to the tip of the extended finger. This forces distal phalanx flexion and disruption of the extensor mechanism at the distal interphalangeal joint. Open injuries to the extensor mechanism can also cause mallet finger.

Question 23

Treatment of a type I mallet finger is typically closed. This involves:

Explanation

Cast immobilization is excessive and will cause undue stiffness in the affected finger. Dorsal blocking splints, splinting in flexion, and early active motion are contraindicated in these injuries. Only the affected joint should be splinted in extension.

Question 24

Type I mallet finger injuries must be immobilized constantly for a minimum of:

Explanation

Eight weeks of immobilization is preferred. If the finger is immobilized for a shorter period of time, the clock is reset and immobilization is started again.

Question 25

The most common mallet finger injuries are:

Explanation

Type I mallet injuries are by far the most common mallet injuries. There is no such classification as a type V injury.

Question 26

On physical examination, a mallet finger assumes a:

Explanation

The distal phalanx assumes a resting flexed posture. The patient is not able to actively extend the fingertip, but it can be passively extended.

Question 27

The following mallet finger injuries always require tendon repair:

Explanation

Type II and III injuries have absolute requirements for tendon repair as there is a laceration or loss of tendon substance.

Question 28

After placing a type I mallet finger in a splint at the initial visit, next follow- up should be:

Explanation

After placement of the splint, the patient should follow-up in the next week to make sure the finger is still maintained in full extension. Loosening of the splint will occur as swelling decreases.

Question 29

The most common bone tumor of the upper extremity is:

Explanation

Osteochondromas are the most common primary benign bony tumors.

Question 30

The most common benign bone tumor of the hand is:

Explanation

Unlike the entire upper extremity, enchondromas are the most common tumors of the hand.

Question 31

Osteochondromas are benign but can have a malignant transformation in which of the following cases:

Explanation

Diaphyseal achalasia, also known as multiple hereditary exostoses, has a risk of malignant degeneration in up to 25% patients. Olliers disease and Mafucciâ s syndrome are associated with enchondromas. There is no lesion called an osteochondromatosis malignant transformans.

Question 32

The risk of malignant transformation in patients with multiple hereditary exostoses is:

Explanation

The rate of malignant transformation in patients with multiple hereditary exostoses is variable and is generally reported between 0.5% to 25%.

Question 33

Recurrence of osteochondroma is likely if:

Explanation

The cartilaginous portion of an osteochondroma is the neoplastic part; its complete excision is essential to avoid recurrences.

Question 34

Malignant transformation of osteochondroma commonly occurs to:

Explanation

Osteochondroma is a cartilaginous tumor and malignant transformation is to a low-grade chondrosarcoma.

Question 35

All of the following suggest a possibility of malignant transformation in multiple hereditary exostoses except:

Explanation

Stippling on radiographs in the cap is due to calcification and is a common characteristic of cartilaginous tumors.

Question 36

Enchondromas are commonly involved in which of the following sites:

Explanation

Metacarpals and phalanges are the most common areas of hand involvement, and the hand is involved in 40% to 65% of cases. Enchondromas are also the most common primary benign bone tumor of the hand (90% cases).

Question 37

The most common forearm deformity in patients with hereditary multiple osteochondromatosis is:

Explanation

Ulnar involvement and shortening frequently occurs in patients with hereditary multiples osteochondromatosis because the distal ulnar growth plate is smaller than that of the radius, consequently its length is affected more. The ulnar shortening causes radial bowing or radial head dislocation.

Question 38

A 12-year-old boy is brought to the clinic by his concerned parents. The boyâ s forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungâ s deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the patientâ s forearm. The anteroposterior radiograph is shown (Slide). The next step is to order a:

Explanation

The next step is to order a skeletal survey to rule out involvement of other areas.

Question 39

A 12-year-old boy is brought to the clinic by his concerned parents. The boyâ s forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. An immediate appointment for magnetic resonance imagine (MRI) and computed tomography (C T) scan are not available, and a genetic evaluation has been carried out previously. As you await the report from the geneticist office, you decide to get a skeletal radiograph series on the patient. The radiograph of the opposite forearm (Slide 1) and right leg are shown (Slide 2). You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 3). Your suspected diagnosis is:

Orthopedic Prometric Exam Question

Explanation

Diaphyseal achalasia, also called multiple hereditary exostoses, classically presents in a young individual with multiple sites of involvement. The more involved the disease, the more likely hand involvement becomes. Forearm involvement is also common. The radius is bowed due to the shortened ulna. The risk of radial head dislocation is higher if the radius does not bow. While infection or traumatic injury could have produced early physeal arrest as seen in the first radiograph, presence of lesions elsewhere indicates multiple hereditary exostoses and should be investigated with skeletal surveys. Multiple epiphyseal dysplasia is not a possible diagnosis as only the ulna is involved in the first radiograph and radius alone in the left forearm. No enchondromas are present.

Question 40

A 12-year-old boy is brought to the clinic by his concerned parents. The boys forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). The genetic pattern seen in patients with this type of presentation is:

Orthopedic Prometric Exam Question

Explanation

Multiple hereditary exostoses is inherited in an autosomal-dominant manner with 90% penetrance.

Question 41

A 12-year-old boy is brought to the clinic by his concerned parents. The boy s forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). Which of the following areas is unlikely to be involved:

Orthopedic Prometric Exam Question

Explanation

The clavicle is a membranous bone, and osteochondromas do not arise in membranous bones.

Question 42

A 12-year-old boy is brought to the clinic by his concerned parents. The boyâ s forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungâ s deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). The chance of hand involvement in this child is:

Explanation

The hand is involved in 30% to 80% of cases.

Question 43

A 12-year-old boy is brought to the clinic by his concerned parents. The boyâ s forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). The most likely complication in this child is:

Orthopedic Prometric Exam Question

Explanation

Ulnar carpal translocation occurs due to the steep radial articular angulation that occurs due to the tethering effect of a shortened ulna and is already apparent in early stages in the first radiograph. While peroneal palsy is possible due to a proximal fibula lesion, it is less common. Malignant transformation occurs, risk varies with families.

Question 44

A 12-year-old boy is brought to the clinic by his concerned parents. The boys forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). The difference between Madelungâ s deformity and this boyâ s condition is:

Orthopedic Prometric Exam Question

Explanation

The ulna is elongated or dorsally subluxed in Madelung's deformity.

Question 45

A 12-year-old boy is brought to the clinic by his concerned parents. The boys forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). All of the following are acceptable options, either alone or in combination, for management of this childâ s condition, except:

Orthopedic Prometric Exam Question

Explanation

Although hemiphyseal stapling is an acceptable option to correct radial articular angulation, in this boy the distal radial physis is already fused as is seen in the first radiograph.

Question 46

A 12-year-old boy is brought to the clinic by his concerned parents. The boys forearm is bowed, and his parents are confused as to the possible diagnosis and treatment options. You notice that the right forearm of the child is bowed ulnarwards and is shorter compared to the left forearm. The pronosupination is markedly decreased on the right side but is also limited on the left side. The patient has a good grip, pinch, and grasp. He is neurologically intact as well. The parents say that they first noticed the deformity around 6 or 7 years ago, and the mother informs you that she had noticed a hard bump on the forearm. She has recently noticed another bump on his right leg. The child does not complain of pain and is using both of his hands quite well. The parents were informed by a previous physician that the child has Madelungs deformity and are concerned that the disease is now involving other areas of his body. You order a radiograph of the forearm. The anteroposterior radiograph is shown (Slide 1). The childâ s skeletal radiograph survey is also presented (Slide 2 and Slide 3). Which of the following is not true regarding the possibility of malignant degeneration in this child:

Orthopedic Prometric Exam Question

Explanation

Bone scan cannot differentiate between an active lesion and a malignant transformation.

Question 47

Horners syndrome includes all of the following except:

Explanation

Horners syndrome is caused by disruption of sympathetic innervation and is characterized by enophthalmosis, not exophthalmosis. Other symptoms include anhidrosis, miosis, and ptosis.

Question 48

Axonotmesis involves injury to the:

Explanation

Axontmesis, as described in Seddonâ s classification, implies injury to the axon and myelin sheath. Neurontmesis involves injury to all three layers.

Question 49

All of the following may be seen with preganglionic lesion except:

Explanation

Tinels sign is seen with postganglionic lesions.

Question 50

Weakness is not seen with root avulsion in the:

Explanation

The trapezius is innervated by spinal accessory nerve and thus will not be involved in a brachial plexus lesion. In the case of a preganglionic lesion, all muscles innervated by the nerve roots will be affected.

Question 51

A 1-year-old child presents with simple syndactyly of the middle and ring fingers. What is the most appropriate timing and rationale for surgical release?

Explanation

Simple syndactyly of the middle and ring fingers is optimally released between 12 and 18 months of age. Releasing earlier risks significant scar contracture, while later release may interfere with normal grasp and fine motor development.

Question 52

A 25-year-old male sustains a displaced basicervical femoral neck fracture. Biomechanically, which of the following is the most appropriate fixation method?

Explanation

Basicervical femoral neck fractures are extracapsular and behave biomechanically like intertrochanteric fractures. A sliding hip screw (SHS) provides superior biomechanical stability compared to cancellous screws, which have a high failure rate in this pattern.

Question 53

During a physical examination of a patient with a suspected anterior cruciate ligament (ACL) injury, a positive pivot shift test is elicited. This test primarily evaluates the competency of which functional bundle of the ACL?

Explanation

The posterolateral (PL) bundle of the ACL is tight in extension and is the primary restraint to rotatory instability. The pivot shift test specifically evaluates this rotatory stability provided by the PL bundle.

Question 54

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

Explanation

Denosumab is a fully human monoclonal antibody that binds directly to the Receptor Activator of Nuclear factor Kappa-B Ligand (RANKL). This prevents RANKL from activating the RANK receptor on osteoclasts and giant cells, thereby inhibiting their function and bone resorption.

Question 55

A 45-year-old man presents to the emergency department with acute saddle anesthesia, bilateral radiculopathy, and urinary retention secondary to a massive L4-L5 disc herniation. Current literature suggests that decompression within what time frame from the onset of symptoms provides the most significant improvement in urologic outcomes?

Explanation

Cauda Equina Syndrome is a surgical emergency. Evidence strongly indicates that surgical decompression performed within 48 hours of symptom onset is associated with the best chance of significant urologic and neurologic recovery.

Question 56

An infant with Developmental Dysplasia of the Hip (DDH) is being treated with a Pavlik harness. If the anterior straps are adjusted to place the hips in excessive hyperflexion (greater than 120 degrees), the child is at highest risk for developing which of the following complications?

Explanation

Hyperflexion of the hip in a Pavlik harness compresses the femoral nerve against the inguinal ligament, leading to a femoral nerve palsy. Conversely, excessive abduction places the infant at high risk for avascular necrosis (AVN) of the femoral head.

Question 57

The Martin-Gruber anastomosis is a well-described anatomical variant in the upper extremity. It involves the anomalous crossing of nerve fibers in the forearm from the:

Explanation

The Martin-Gruber anastomosis occurs in the forearm when motor fibers cross from the median nerve or anterior interosseous nerve to the ulnar nerve. These fibers typically go on to innervate intrinsic muscles of the hand.

Question 58

A 35-year-old construction worker falls from a height and sustains a closed, highly comminuted, intra-articular calcaneus fracture. On examination in the ED, he has massive swelling and severe fracture blisters over the lateral hindfoot. What is the most appropriate initial management?

Explanation

In the presence of massive swelling and fracture blisters, definitive ORIF through an extensile lateral approach should be delayed until the soft tissues have healed and the "wrinkle sign" is present. Premature incision carries an unacceptably high risk of wound necrosis and deep infection.

Question 59

Which of the following transcription factors is considered the essential "master regulator" for the differentiation of mesenchymal stem cells into osteoblasts?

Explanation

RUNX2 (also known as Core-binding factor subunit alpha-1 or Cbfa1) is the master transcription factor for osteoblast differentiation. SOX9 regulates chondrogenesis, and PPAR-gamma drives adipogenesis.

Question 60

A 30-year-old male sustains an anteroposterior compression (APC) Type III pelvic ring injury following a high-speed motor vehicle collision. He is hemodynamically unstable. The primary source of life-threatening retroperitoneal hemorrhage in pelvic fractures is most commonly from:

Explanation

While arterial bleeding (e.g., from branches of the internal iliac) can occur and is severe, approximately 80-90% of pelvic hemorrhage originates from the low-pressure presacral venous plexus and exposed cancellous bone at the fracture sites.

Question 61

A patient who underwent a metal-on-metal total hip arthroplasty three years ago presents with groin pain and swelling. MRI reveals a large pseudotumor. Histology shows an aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL). This reaction is classically described as which type of hypersensitivity?

Explanation

Adverse local tissue reactions (ALTR) such as ALVAL and pseudotumors in metal-on-metal implants are driven by a Type IV (delayed, cell-mediated) hypersensitivity response to metal wear debris.

Question 62

A 24-year-old female sustains a Levine-Edwards Type IIA traumatic spondylolisthesis of the axis (Hangman's fracture). What is the mechanism of injury, and what is a critical consideration in her management?

Explanation

A Levine-Edwards Type IIA Hangman's fracture involves a flexion-distraction injury resulting in severe angulation without significant translation. Cervical traction is contraindicated as it can cause over-distraction and catastrophic spinal cord injury.

Question 63

In a child diagnosed with Legg-Calvé-Perthes disease (idiopathic avascular necrosis of the proximal femoral epiphysis), what is the single most significant independent prognostic factor for developing premature hip osteoarthritis in adulthood?

Explanation

Age at clinical onset is the most critical prognostic factor in Legg-Calvé-Perthes disease. Children who present at a younger age (typically under 6 to 8 years) have significantly more time for remodeling and generally achieve much better long-term outcomes.

Question 64

When evaluating a patient with recurrent anterior shoulder instability, what specifically defines an "off-track" Hill-Sachs lesion?

Explanation

The glenoid track concept evaluates the interaction between glenoid bone loss and the Hill-Sachs lesion. An "off-track" lesion occurs when the Hill-Sachs interval is wider than the remaining intact glenoid track, causing the lesion to engage the anterior glenoid rim during abduction and external rotation.

Question 65

A 25-year-old male presents with knee pain. Radiographs show an eccentric, expansile, purely lytic lesion in the distal femoral epiphysis. Biopsy reveals multinucleated giant cells. Which genetic mutation is highly sensitive and specific for this tumor?

Explanation

Giant Cell Tumor of bone is classically an epiphyseal/metaphyseal lesion in skeletally mature patients. It is characterized molecularly by a mutation in the H3F3A (Histone H3.3) gene in over 90% of cases.

Question 66

A newborn presents with radial longitudinal deficiency (radial club hand). If Holt-Oram syndrome is suspected as the underlying genetic etiology, what is the most common associated congenital cardiac anomaly?

Explanation

Holt-Oram syndrome is characterized by upper limb defects (often radial sided) and congenital heart disease. An atrial septal defect (secundum type) is the most common cardiac anomaly seen in these patients.

Question 67

In an APC-II (Anteroposterior Compression type II) pelvic ring injury, which of the following ligaments remains intact, thereby preventing complete vertical instability?

Explanation

In APC-II injuries, the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments tear, causing rotational instability. The posterior sacroiliac ligament remains intact, maintaining vertical stability of the pelvis.

Question 68

Which of the following clinical or pathologic findings represents the most significant adverse prognostic factor for overall survival in a 16-year-old patient diagnosed with high-grade intramedullary osteosarcoma of the distal femur?

Explanation

While poor histologic response to chemotherapy (<90% necrosis) is a very strong prognostic factor, the presence of macroscopic metastatic disease (typically pulmonary) at presentation is the single most significant adverse prognostic indicator for overall survival.

Question 69

A 65-year-old male presents with deteriorating fine motor skills, gait instability, and bilateral Hoffman's signs. MRI demonstrates cervical spondylotic myelopathy. Which specific MRI finding is considered the most reliable indicator of a poor postoperative neurological prognosis?

Explanation

Myelomalacia, indicated by a focal T1 hypointensity within the spinal cord, suggests permanent cystic or gliotic changes. This finding correlates heavily with poor postoperative neurological recovery compared to isolated T2 hyperintensity.

Question 70

In modern total hip arthroplasty (THA), the selection of a ceramic-on-ceramic bearing surface is uniquely associated with which of the following postoperative complications?

Explanation

Ceramic-on-ceramic bearings offer extremely low wear rates but are uniquely associated with an audible squeaking sound in a small percentage of patients, which can be distressing and is often related to component malposition or microseparation.

Question 71

During an anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft, a resident places the femoral tunnel too anteriorly. What classical clinical finding will be observed during intraoperative graft tensioning?

Explanation

An anteriorly placed femoral tunnel captures the graft in flexion, increasing tension as the knee bends. This leads to severe tightness in flexion and subsequent laxity in extension as the graft stretches.

Question 72

A 45-year-old male sustains a vertically oriented, displaced femoral neck fracture (Pauwels Type III). What is the primary biomechanical rationale for augmenting standard inverted-triangle cannulated screw fixation with a medially placed anti-glide plate?

Explanation

Pauwels Type III fractures possess a steep angle (>50 degrees), subjecting them to high vertical shear forces that lead to failure of simple screw constructs. A medial buttress or anti-glide plate specifically neutralizes these shear forces.

Question 73

A 4-month-old infant is undergoing closed reduction for developmental dysplasia of the hip (DDH). The intraoperative arthrogram demonstrates medial pooling of dye and a failure to achieve concentric reduction. Which anatomic structure most commonly blocks closed reduction extracapsularly?

Explanation

While the pulvinar, ligamentum teres, and transverse acetabular ligament are common intracapsular blocks to reduction, the iliopsoas tendon is classically the most significant extracapsular block to closed reduction in DDH.

Question 74

During fracture healing via endochondral ossification, the production of Type X collagen in the fracture callus is primarily mediated by which of the following cell types?

Explanation

Hypertrophic chondrocytes in the callus specifically express and produce Type X collagen. This structural protein facilitates the calcification of the cartilage matrix, a crucial step before invasion by blood vessels and osteoprogenitor cells.

Question 75

A 25-year-old male falls on an outstretched hand and sustains a proximal pole scaphoid fracture. What is the major arterial supply to the scaphoid that makes this specific fracture pattern highly prone to avascular necrosis?

Explanation

The dorsal carpal branch of the radial artery enters the scaphoid at the dorsal ridge (distal to the waist) and supplies 70-80% of the bone via retrograde flow. Fractures at the proximal pole disrupt this retrograde supply, leading to high rates of avascular necrosis.

Question 76

A 22-year-old football player sustains a high-energy midfoot injury. Radiographs show widening between the 1st and 2nd metatarsal bases.

Which ligamentous connection is anatomically disrupted in a classic Lisfranc injury?

Explanation

The primary Lisfranc ligament connects the lateral aspect of the medial cuneiform to the medial base of the second metatarsal. There is no direct ligamentous connection between the first and second metatarsal bases.

Question 77

A 13-year-old obese boy presents with left thigh pain and an obligatory external rotation of the hip during active flexion. A diagnosis of Slipped Capital Femoral Epiphysis (SCFE) is made. What is the most devastating complication associated with forceful closed reduction of a displaced SCFE?

Explanation

Forceful or non-gentle closed reduction of a SCFE significantly increases the risk of avascular necrosis of the femoral head by kinking or tearing the already tenuous retinacular blood supply.

Question 78

A 30-year-old male with a closed tibial shaft fracture develops disproportionate pain out of proportion to the injury. He complains of severe paresthesias in the first dorsal web space of the foot. Which fascial compartment of the leg is most likely experiencing critically elevated tissue pressures?

Explanation

The deep peroneal nerve courses through the anterior compartment of the leg and provides sensation exclusively to the first dorsal web space. Paresthesias in this distribution are a hallmark of impending anterior compartment syndrome.

Question 79

Five years following a primary total knee arthroplasty, a patient presents with pain and progressive varus deformity. Radiographs reveal focal osteolysis around the medial tibial plateau without systemic signs of infection.

What is the predominant cell type mediating this periprosthetic osteolysis?

Explanation

Aseptic periprosthetic osteolysis is primarily a macrophage-mediated foreign body inflammatory response. Macrophages phagocytose particulate wear debris (like polyethylene), releasing cytokines that activate osteoclasts.

Question 80

A 40-year-old falls from a height and sustains an L1 thoracolumbar burst fracture. Which of the following criteria most strongly mandates surgical stabilization rather than conservative management with a TLSO brace?

Explanation

Absolute indications for surgical intervention in thoracolumbar burst fractures include progressive neurological deficits. Other strong indications include disruption of the posterior ligamentous complex (PLC), >30 degrees of kyphosis, or >50% loss of vertebral height.

Question 81

A 24-year-old overhead throwing athlete presents with posterior shoulder pain. Physical examination reveals a positive active compression test (O'Brien test) that elicits deep joint pain with the forearm pronated, which is relieved with the forearm in supination. What is the most likely associated finding on MR arthrography?

Explanation

The active compression test (O'Brien test) is sensitive for SLAP tears. Pain is characteristically elicited with the arm in internal rotation/pronation (which tensions the biceps root) and relieved when the arm is supinated.

Question 82

According to the Sunderland classification of peripheral nerve injury, which of the following histological descriptions correctly defines a fourth-degree nerve injury?

Explanation

In a Sunderland grade IV injury, all internal neural and supporting elements (axon, endoneurium, perineurium) are disrupted, leaving only the outermost epineurium intact. Spontaneous recovery is highly unlikely due to severe internal scarring.

Question 83

A newborn presents with an absent radius and an absent thumb. Which of the following tests is most appropriate to rule out a life-threatening associated condition?

Explanation

A newborn with an absent radius and absent thumb is highly suspicious for Fanconi anemia, which is fatal if missed due to aplastic anemia. A chromosomal breakage test using diepoxybutane is mandatory for diagnosis.

Question 84

A 12-year-old boy presents with a pathologic fracture through a radiolucent lesion in the proximal humerus.

The "fallen leaf" sign is seen. What is the most appropriate initial management after the fracture has healed?

Explanation

The "fallen leaf" sign is pathognomonic for a unicameral bone cyst (UBC). First-line treatment for active, symptomatic UBCs often involves aspiration and intralesional injection of methylprednisolone or bone marrow.

Question 85

According to the Wassel classification of thumb polydactyly, which type is the most common and involves duplication at the metacarpophalangeal joint?

Explanation

Wassel Type IV, characterized by a bifid proximal phalanx and duplication of the distal phalanx, is the most common form of preaxial polydactyly. It accounts for approximately 40-50% of all thumb duplications.

Question 86

In a patient with a displaced midshaft clavicle fracture, which of the following is considered an absolute indication for operative fixation?

Explanation

Absolute indications for operative fixation of a clavicle fracture include open fractures, associated neurovascular injury, and severe skin compromise causing ischemia. Displacement and shortening are relative indications.

Question 87

A 35-year-old laborer sustains a severe laceration to his index finger requiring flexor tendon repair.

Which of the following pulley combinations is most critical to preserve or reconstruct to prevent biomechanical bowstringing?

Explanation

The A2 and A4 pulleys insert directly onto the phalangeal shafts and are the most critical biomechanical pulleys. Preserving or reconstructing them is essential to prevent flexor tendon bowstringing and loss of digital motion.

Question 88

A 65-year-old diabetic patient presents with severe back pain and elevated inflammatory markers. MRI confirms pyogenic spondylodiscitis at L3-L4. What is the most common causative organism for this condition?

Explanation

Staphylococcus aureus is the most common causative organism in pyogenic spondylodiscitis across all patient demographics. Empiric antibiotic therapy should provide robust coverage for this pathogen.

Question 89

Which of the following bearing surface combinations in total hip arthroplasty has the lowest volumetric wear rate but carries the highest risk of catastrophic brittle failure?

Explanation

Ceramic-on-ceramic bearings offer the lowest volumetric wear rate among total hip arthroplasty options. However, they carry a unique risk of catastrophic brittle fracture and potential squeaking.

Question 90

A 25-year-old athlete sustains a twisting knee injury. MRI reveals a full-thickness anterior cruciate ligament (ACL) tear and a displaced bucket-handle tear of the medial meniscus. What is the most appropriate management?

Explanation

Concurrent ACL reconstruction and meniscal repair provides optimal knee stability and protects the meniscal repair. The hemarthrosis generated by the ACL reconstruction also enhances the biological environment for meniscal healing.

Question 91

A 13-year-old obese boy presents with a 3-week history of left thigh pain and a limp.

On physical examination, his left hip obligatorily externally rotates when flexed. What is the most appropriate definitive treatment?

Explanation

The clinical presentation of obligatory external rotation with hip flexion in an obese adolescent is classic for slipped capital femoral epiphysis (SCFE). The gold standard treatment is in situ fixation with a single cannulated screw.

Question 92

Which of the following bone tumors is characterized histologically by a proliferation of mononuclear cells and multinucleated giant cells, frequently harboring an H3F3A gene mutation?

Explanation

Giant cell tumor of bone is a locally aggressive benign neoplasm characterized by multinucleated giant cells. Up to 95% of these tumors harbor a specific mutation in the H3F3A histone gene.

Orthopedic Prometric Exam Preparation MCQs - Part 1

Orthopedic Prometric Exam Preparation MCQs - Part 10

Orthopedic Prometric Exam Preparation MCQs - Part 10

Chapter Index