If the structure marked by the tip of the probe in Figure 94 is repaired to the bony glenoid with suture anchors during an arthroscopic stabilization procedure, what is the most likely result? Review Topic

Loss of external rotation with the arm at the side of the body

Figure 43 shows an arthroscopic view of the posteromedial compartment of a patient’s left knee using a 70-degree arthroscope placed through the intercondylar notch. The arrow is pointing to what structure?

Posterior horn of the medial meniscus

1and2demonstratetheradiographsobtainedfromayear-oldwomanwithend-stagedebilitatingosteoarthritisoftherighthip.Sheiscontemplatingtotalhiparthroplasty(THA).Shehasa historyofrighthipdysplasiaandunderwenthiposteotomyasanadolescent.Overtheyears,nonsurgical

MRI with metal artifact reduction sequence (MARS) only. B. serum cobalt only.

Figure 48 shows the radiograph of a 17-year-old boy who sustained a gunshot wound to his forearm. There is a small entrance wound on the volar surface. The exit wound is dorsal and more than 15 cm in size, with loss of skin and an extensive amount of

Open reduction and internal fixation of the radius with free fibular flap interposition

ofhat parameter is most commonly used to estimate the maximum tension a muscle can generating?

Physiologic cross-sectional area

Compared to similar patients who do not donate autologous blood, patients with normal baseline hemoglobin who donate autologous blood prior to undergoing primary total hip arthroplasty are likely to

have a greater likelihood of receiving a transfusion perioperatively.

A 43-year-old woman has an enlarging mass in the left groin. A radiograph, CT scan, and a biopsy specimen are shown in Figures 42a through 42c. Treatment should consist of

wide resection of the ischiopelvic region inferior to the acetabulum.

A 51-year-old woman with shoulder pain responds transiently to a subacromial injection and physical therapy exercise program. When her symptoms recur, an arthroscopic subacromial decompression is recommended. During the surgery, a partial-thickness a

Arthroscopic tendon debridement and subacromial decompression

Free Orthopedics Review MCQs & Practice | Dr Hutaif

Question 1

A 68-year-old female, who has been on alendronate for 12 years, presents with a 3-month history of insidious, dull aching pain in her left thigh, aggravated by weight-bearing. She denies any specific trauma. Physical examination reveals tenderness over the lateral aspect of her proximal femur. Radiographs show significant cortical thickening of the left subtrochanteric femur with a small, incomplete transverse lucency in the lateral cortex. What is the most appropriate next step in management?

Explanation

The patient presents with classic signs and symptoms of an incomplete atypical femoral fracture (AFF) associated with long-term bisphosphonate use: prodromal thigh pain, cortical thickening, and a transverse lucency in the subtrochanteric region. The most appropriate initial management for an incomplete AFF is discontinuation of the bisphosphonate, pain control, protected weight-bearing (often with crutches), and optimizing calcium and vitamin D levels. Surgical stabilization with an intramedullary nail is typically reserved for complete AFFs or highly symptomatic impending fractures that fail conservative management. Continuing alendronate or solely prescribing NSAIDs is inappropriate given the diagnosis. A bone scan might be useful to rule out other pathology, but the clinical and radiographic picture is highly suggestive of AFF, and the primary management decision hinges on this diagnosis.

Question 2

A 10-year-old boy with cerebral palsy presents with a rapidly progressive thoracolumbar scoliosis measuring 80 degrees, causing significant trunk imbalance and difficulty with seating. He has a history of non-ambulatory status and recurrent respiratory infections. Which of the following is the primary indication for surgical intervention in this patient, beyond cosmetic concerns?

Explanation

For non-ambulatory patients with neuromuscular scoliosis, the primary indication for surgical intervention is often to improve sitting balance, correct pelvic obliquity, and prevent pressure sores, thereby enhancing quality of life and facilitating care. While severe curves can lead to pulmonary compromise, surgical correction in non-ambulatory patients typically results in only modest improvements in pulmonary function, and preventing restrictive lung disease is a secondary goal compared to seating balance. Pain is less common in this population compared to idiopathic scoliosis. Restoration of ambulatory function is not an indication for surgery in a non-ambulatory patient. Preventing progression is a general indication, but for curves this severe, functional improvement takes precedence.

Question 3

A 55-year-old male presents with acute onset bilateral leg weakness, urinary retention, and saddle anesthesia following a lumbar discectomy performed 2 days prior. His symptoms are rapidly worsening. On examination, he has diminished rectal tone and absent ankle reflexes bilaterally. What is the most crucial diagnostic step to undertake immediately?

Explanation

The patient's symptoms (bilateral leg weakness, urinary retention, saddle anesthesia, diminished rectal tone, absent ankle reflexes) are classic for cauda equina syndrome (CES). Given the recent lumbar discectomy and rapidly worsening symptoms, the most crucial and immediate step is urgent surgical exploration of the lumbar spine. This is to decompress the neural elements, likely due to a retained disc fragment, epidural hematoma, or seroma. While an MRI would confirm the diagnosis and identify the precise compressive lesion, in a rapidly progressive post-operative CES, surgical exploration should not be delayed by imaging if the clinical suspicion is high and the patient is unstable. Electromyography is not for acute diagnosis. Corticosteroids are not indicated and delay definitive treatment. Conservative management is contraindicated in acute CES.

Question 4

A 32-year-old male sustains a high-energy anterior-posterior compression (APC-III) pelvic ring injury after a motor vehicle collision. He is hemodynamically unstable despite initial fluid resuscitation. Which of the following interventions should be prioritized after initial resuscitation and external pelvic stabilization?

Explanation

In a hemodynamically unstable patient with a high-energy APC-III pelvic fracture that remains unstable despite initial resuscitation and external pelvic stabilization (e.g., sheet, binder), persistent hemorrhage is often due to arterial bleeding from the internal iliac artery system. Angiographic embolization is the gold standard for controlling arterial hemorrhage in this setting. While external fixators provide definitive mechanical stabilization, they do not directly control arterial bleeding. Laparotomy is for intra-abdominal bleeding (typically venous, less common in APC-III causing massive instability) or bowel injury. Urethral injury assessment can be performed but is secondary to life-threatening hemorrhage control.

Question 5

A 68-year-old male underwent a total knee arthroplasty 8 years ago. He now presents with increasing knee pain, swelling, and warmth for 3 months, without preceding trauma. His ESR is 75 mm/hr and CRP is 85 mg/L. Joint aspiration yields a cloudy fluid. Which of the following synovial fluid analyses is most indicative of a chronic periprosthetic joint infection?

Explanation

For diagnosing chronic periprosthetic joint infection (PJI) of the knee, the Musculoskeletal Infection Society (MSIS) criteria (and similar guidelines) generally define PJI based on a synovial fluid white blood cell (WBC) count of >3,000 cells/µL and/or a neutrophil percentage of >60-80%. Option C (15,000 cells/µL with 80% neutrophils) clearly meets these criteria, indicating a high likelihood of infection. Option B is borderline and might be considered suspicious but less definitive. Option A suggests an aseptic process. Option D is more indicative of an acute septic arthritis or acute PJI. Option E suggests crystal-induced arthropathy, which can mimic infection but is not PJI.

Question 6

A 16-year-old male is diagnosed with high-grade osteosarcoma of the distal femur. Staging CT chest reveals multiple small pulmonary nodules consistent with metastatic disease. Biopsy confirms classic osteosarcoma histology. What is the most appropriate initial management approach?

Explanation

For high-grade osteosarcoma, especially with metastatic disease, the standard of care involves neoadjuvant (pre-operative) chemotherapy. This serves to decrease tumor burden, treat micrometastatic disease, and assess tumor response to chemotherapy, which is prognostic. Following a complete course of neoadjuvant chemotherapy, surgical resection of all identifiable primary and metastatic disease (if resectable) is performed. Amputation is generally reserved for cases where limb salvage is not feasible. Immediate surgery without neoadjuvant chemotherapy for metastatic disease is not standard. Radiation therapy is typically used for palliative purposes or in unresectable cases, not as the primary curative intent. Immunotherapy is currently largely investigational in primary osteosarcoma.

Question 7

A 28-year-old carpenter presents with progressive right hand weakness and numbness over the past 6 months, primarily affecting the thumb, index, and middle fingers. He reports a constant dull ache in the forearm. Physical examination reveals thenar atrophy, weakness of thumb opposition and abduction, and positive Tinel's sign at the wrist. Nerve conduction studies show severe carpal tunnel syndrome. He has undergone two steroid injections with only transient relief. What is the most significant factor influencing the outcome of surgical release in this patient?

Explanation

For carpal tunnel syndrome, the most significant factor influencing the outcome of surgical release is the severity and duration of preoperative nerve compression, particularly as manifested by motor weakness and thenar atrophy. Severe, long-standing compression can lead to irreversible axonal damage and muscle atrophy, limiting the extent of functional recovery post-operatively. While age and activity can play a role, and chronic pain can be debilitating, the extent of nerve damage is paramount. The type of surgical incision (open vs. endoscopic) has not been shown to significantly impact long-term functional outcomes. Associated cervical radiculopathy can complicate the clinical picture but isn't the primary determinant of outcome for the carpal tunnel release itself.

Question 8

A 55-year-old diabetic male with a history of peripheral neuropathy presents with a red, swollen, and warm midfoot. Radiographs show disorganization and fragmentation of the tarsometatarsal joints with a 'rocker-bottom' deformity. His WBC count is normal, and there are no open wounds. What is the most appropriate initial management strategy?

Explanation

The patient's presentation (diabetic neuropathy, red/swollen/warm midfoot, radiographic changes of disorganization and fragmentation, 'rocker-bottom' deformity) is classic for acute Charcot neuroarthropathy. In the acute (Eichenholtz Stage I - fragmentation and disorganization) phase, the primary management is strict non-weight bearing and immobilization in a total contact cast or CAM boot to protect the foot from further collapse and allow for bone consolidation. Surgical fusion is generally reserved for the chronic (Stage III - coalescence/consolidation) phase, or for severe deformity that cannot be accommodated by bracing and leads to recurrent ulceration, and is not an initial treatment for acute Charcot. Systemic antibiotics are not indicated unless there is a confirmed infection, and the normal WBC and absence of open wounds make infection less likely as the primary issue. Corticosteroids are not a standard treatment. Amputation is a last resort for uncontrolled infection or severe deformity with intractable ulceration.

Question 9

A 22-year-old professional soccer player sustains a severe knee injury involving rupture of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and posterolateral corner (PLC). He undergoes staged surgical reconstruction of all ligaments. Which of the following is the most critical factor to consider when determining his readiness for return to professional-level sports?

Explanation

For high-level professional athletes returning after complex multi-ligament knee reconstruction, psychological readiness is increasingly recognized as a paramount factor, often dictating the success and durability of their return to sport. Even if physical parameters like strength, range of motion, and functional test scores are met, a lingering fear of re-injury, lack of confidence, or an inability to emotionally tolerate the demands of competition can significantly impair performance and increase the risk of re-injury. While time elapsed, resolution of effusion, full range of motion, and objective strength/functional testing are all necessary prerequisites, psychological readiness acts as the gatekeeper for successful and sustainable return to elite-level sports.

Question 10

A 40-year-old male develops severe, burning pain, allodynia, hyperalgesia, swelling, and changes in skin temperature and color in his left foot 3 weeks after an ankle fracture. Radiographs show no abnormalities beyond the healing fracture. Nerve conduction studies are normal. Which of the following non-pharmacological interventions has demonstrated the most consistent efficacy in the early management of this condition?

Explanation

The patient's symptoms are highly suggestive of Complex Regional Pain Syndrome (CRPS) Type 1. In the early stages of CRPS, a multidisciplinary approach is crucial, involving pain management, physical therapy, and psychological support. Among the non-pharmacological interventions, mirror therapy has demonstrated consistent efficacy, particularly in early CRPS, by addressing the cortical reorganization thought to be involved in the pathophysiology. Graded motor imagery is also effective. While sympathetic nerve blocks can provide pain relief, they are more invasive and not typically the initial non-pharmacological intervention of choice. Spinal cord stimulators are reserved for refractory chronic CRPS. TENS has limited evidence for CRPS.

Question 11

What is the most common anatomical source of hemorrhage in a hemodynamically unstable patient with an anterior-posterior compression (APC) pelvic ring injury?

Explanation

Venous bleeding accounts for up to 80% of hemorrhage in pelvic fractures, primarily from the presacral venous plexus. Arterial bleeding is less common but often involves the superior gluteal artery in lateral compression injuries or the internal pudendal in APC injuries.

Question 12

A 12-year-old obese male presents with acute, severe left hip pain and inability to bear weight after a minor fall. He reports a 3-month history of mild, intermittent left groin pain. Radiographs confirm a slipped capital femoral epiphysis (SCFE). Which of the following factors most significantly increases the risk of avascular necrosis (AVN) in this patient?

Explanation

According to the Loder classification, an unstable SCFE is defined by the inability to bear weight, even with crutches. Unstable SCFE carries a significantly higher risk of avascular necrosis (up to 47%) compared to stable SCFE.

Question 13

A 25-year-old soccer player sustains a twisting knee injury. On examination, the dial test shows 15 degrees of increased external rotation at 30 degrees of knee flexion compared to the contralateral side, but symmetric rotation at 90 degrees of flexion. Which structure is most likely injured?

Explanation

An isolated injury to the posterolateral corner (PLC), which includes the popliteofibular ligament, presents with increased external rotation at 30 degrees but not at 90 degrees. Combined PLC and PCL injuries exhibit increased external rotation at both 30 and 90 degrees.

Question 14

A 65-year-old male presents with groin pain 5 years after a primary total hip arthroplasty using a metal-on-polyethylene bearing with a modular titanium stem and cobalt-chromium head. Abrasive wear at the head-neck junction (trunnionosis) is suspected. Which of the following serum markers is most likely to be elevated?

Explanation

Mechanically assisted crevice corrosion (MACC) at the modular head-neck junction (trunnionosis) typically produces disproportionately elevated serum cobalt levels compared to chromium. This differs from metal-on-metal bearing wear, which typically produces roughly equal elevations.

Question 15

A 62-year-old female presents with progressive hand clumsiness and difficulty buttoning her shirt. Examination reveals a positive Hoffman sign and hyperreflexia in the lower extremities. Which of the following additional physical examination findings is most specific for cervical spondylotic myelopathy at the C5-C6 level?

Explanation

The inverted brachioradialis reflex indicates a lower motor neuron lesion at C5 or C6 (diminished brachioradialis reflex) and an upper motor neuron lesion below that level (hyperactive finger flexion). It is highly specific for cervical myelopathy at the C5-C6 level.

Question 16

A 15-year-old boy presents with a painful mass in his distal femur. Biopsy reveals small round blue cells with positive CD99 staining. Which of the following chromosomal translocations is most characteristic of this diagnosis?

Explanation

The diagnosis is Ewing sarcoma, which is characterized by small round blue cells and strong membranous CD99 positivity. The pathognomonic chromosomal translocation is t(11;22)(q24;q12), which forms the EWS-FLI1 fusion protein.

Question 17

Sclerostin is a key regulatory protein in bone metabolism targeted by novel osteoporosis medications. Which of the following best describes its mechanism of action in reducing bone formation?

Explanation

Sclerostin, produced by osteocytes, competitively binds to LRP5/6 receptors on osteoblasts. This inhibits the canonical Wnt/beta-catenin signaling pathway, thereby decreasing osteoblastogenesis and bone formation.

Question 18

A 32-year-old male sustains a closed tibial shaft fracture. Twelve hours later, he develops severe pain out of proportion to the injury. His diastolic blood pressure is 80 mmHg. What is the absolute intracompartmental pressure threshold and delta pressure typically indicating the need for emergent four-compartment fasciotomy?

Explanation

Compartment syndrome is a clinical diagnosis, but tissue perfusion is compromised when intracompartmental pressures exceed 30 mmHg or when the delta pressure (diastolic BP minus compartment pressure) falls below 30 mmHg. Emergent fasciotomy is the definitive treatment.

Question 19

A 65-year-old male presents with groin pain 5 years after receiving a metal-on-metal total hip arthroplasty. Aspiration yields sterile, thick, grey fluid. MRI with metal artifact reduction sequence (MARS) shows a solid and cystic mass communicating with the joint space. What is the most likely diagnosis?

Explanation

ALTR or pseudotumor is a known complication of metal-on-metal hip bearings due to a delayed type IV hypersensitivity reaction to metal debris. MARS MRI is the imaging modality of choice to characterize these soft tissue masses.

Question 20

A 4-month-old female is being treated with a Pavlik harness for developmental dysplasia of the hip. At the two-week follow-up, the parents report the infant is no longer actively kicking her left leg, and physical exam reveals absent active knee extension on that side. What is the most appropriate management?

Explanation

The clinical picture describes a femoral nerve palsy, a known complication of hyperflexion in a Pavlik harness. The harness must be discontinued immediately to prevent permanent nerve injury and allow for neurological recovery.

Question 21

A 72-year-old man with a known history of Paget's disease of the bone presents with new-onset, severe, and unrelenting pain in his right humerus. Radiographs demonstrate a destructive, lytic lesion with cortical breakthrough. What is the most likely pathological diagnosis?

Explanation

Malignant transformation occurs in approximately 1% of patients with Paget's disease, most commonly to secondary osteosarcoma. It typically presents as a new onset of severe pain and a destructive lytic lesion on radiographs.

Question 22

A 24-year-old male is brought to the emergency department following a first-time generalized tonic-clonic seizure. He complains of right shoulder pain and an inability to rotate the arm outward. An AP radiograph of the shoulder shows the humeral head overlapping the glenoid with a "lightbulb" sign. What is the next best step in management?

Explanation

The patient has a classic posterior shoulder dislocation, commonly associated with seizures and identified by the "lightbulb" sign on the AP view. Orthogonal imaging, specifically an axillary lateral or scapular Y view, is essential to confirm the diagnosis and assess for associated injuries like a reverse Hill-Sachs lesion before reduction.

Question 23

A 40-year-old carpenter presents with a swollen, erythematous, and painful index finger after sustaining a puncture wound 2 days ago. Which of the following is NOT one of Kanavel's cardinal signs of acute suppurative flexor tenosynovitis?

Explanation

Kanavel's four cardinal signs include fusiform swelling, tenderness along the tendon sheath, resting flexion posture, and pain with passive extension. Pain with active flexion is not one of the specific classic signs, as pain on passive extension is the most sensitive early indicator.

Question 24

A 60-year-old male complains of deteriorating handwriting and unsteadiness while walking. On examination, flicking the nail of his middle finger downward results in reflexive flexion of his thumb and index finger. What is the name of this clinical sign and what does it indicate?

Explanation

Hoffmann's sign is elicited by flicking the distal phalanx of the middle finger, with a positive response being reflexive flexion of the thumb and index finger. It indicates upper motor neuron dysfunction, commonly seen in cervical spondylotic myelopathy.

Question 25

A 25-year-old football player presents with midfoot pain after his foot was axially loaded while plantarflexed. Non-weight-bearing radiographs appear normal. What is the most sensitive initial radiographic view or study to identify an occult Lisfranc injury in this patient?

Explanation

Weight-bearing radiographs are critical for diagnosing occult Lisfranc injuries as the stress reveals widening of the interval between the first and second metatarsal bases. If weight-bearing X-rays are equivocal, an MRI or weight-bearing CT is often the next step.

Question 26

In orthopedic biomechanics, what term describes the phenomenon where a viscoelastic material (like a ligament) demonstrates a continuous increase in strain over time when subjected to a constant load?

Explanation

Creep is the progressive deformation (increasing strain) of a viscoelastic material under a constant load. Stress relaxation, conversely, is the decrease in stress over time when the material is held at a constant strain.

Question 27

A 45-year-old male is brought to the trauma bay after a motorcycle crash. He is tachycardic and hypotensive. Pelvic X-ray reveals a 4 cm widening of the pubic symphysis with disruption of the sacroiliac joints bilaterally. A pelvic binder is to be applied. What is the correct anatomical landmark for the placement of the pelvic binder to optimize reduction?

Explanation

A pelvic binder should be centered over the greater trochanters to effectively close the pelvic ring volume in "open book" (APC-type) injuries. Placing the binder over the iliac crests is ineffective and can paradoxically widen the pelvis or compromise abdominal assessment.

Question 28

A 19-year-old female presents to the ED following a high-speed motor vehicle collision where she was wearing a lap-belt only. Radiographs demonstrate a horizontal fracture through the spinous process, pedicles, and vertebral body of L1. What associated injury must be actively excluded in this patient?

Explanation

Chance fractures are flexion-distraction injuries commonly associated with lap-belt use in motor vehicle collisions. There is a high incidence (up to 50%) of associated intra-abdominal injuries, particularly hollow viscus ruptures, which must be carefully evaluated.

Question 29

A 13-year-old obese boy presents with right groin and knee pain, and an obligatory external rotation of the hip during passive flexion. He is diagnosed with a slipped capital femoral epiphysis (SCFE). Which of the following is a generally accepted indication for prophylactic in situ pinning of the contralateral asymptomatic hip?

Explanation

Prophylactic pinning of the contralateral hip in SCFE is generally recommended for patients with underlying metabolic or endocrine disorders (e.g., hypothyroidism, renal osteodystrophy) due to the high risk of bilateral involvement. It may also be considered in patients who are highly unlikely to follow up.

Question 30

A 70-year-old female undergoes a routine primary total knee arthroplasty for severe valgus osteoarthritis. In the recovery room, she reports numbness in the dorsum of her foot and is unable to actively dorsiflex her ankle. Vascular exam is normal. What is the most likely cause of this complication?

Explanation

Foot drop following TKA is most commonly due to a common peroneal nerve injury, often resulting from stretch during the correction of severe valgus deformities. Immediate management typically involves loosening dressings and positioning the knee in slight flexion to relieve nerve tension.

Question 31

A 5-year-old boy presents with a limp, fever, and refusal to bear weight on his right leg. According to the Kocher criteria, which combination of clinical and laboratory findings yields the highest probability of septic arthritis of the hip?

Explanation

The classic Kocher criteria include non-weight bearing, ESR > 40 mm/hr, WBC > 12,000/mm3, and Temperature > 38.5°C. When all four criteria are met, the probability of septic arthritis in a pediatric hip is estimated to be 99%.

Question 32

A 35-year-old male presents with chronic wrist pain after a fall on an outstretched hand two years ago. Radiographs reveal a scaphoid waist fracture nonunion with sclerosis. MRI shows no gadolinium enhancement in the proximal pole. What does this MRI finding indicate?

Explanation

The lack of gadolinium contrast enhancement in the proximal pole of the scaphoid on MRI is highly indicative of avascular necrosis (AVN). This finding significantly alters the surgical management, often necessitating a vascularized bone graft.

Question 33

A 14-year-old boy presents with severe night pain in his right mid-thigh. Radiographs reveal a diaphyseal destructive lesion with an 'onion-skin' periosteal reaction. A biopsy is performed. Which of the following chromosomal translocations is most characteristic of this tumor?

Explanation

Ewing sarcoma is a small round blue cell tumor classically presenting in the diaphysis of long bones with an 'onion-skin' periosteal reaction. It is strongly associated with the t(11;22) chromosomal translocation, resulting in the EWS-FLI1 fusion protein.

Question 34

A 30-year-old male is brought to the trauma bay intubated after a motorcycle crash. He has a severely comminuted closed tibia fracture. Which of the following intracompartmental pressure measurements is the most reliable indicator for emergent fasciotomy?

Explanation

The delta pressure, defined as the diastolic blood pressure minus the compartment pressure, is the most reliable indicator for compartment syndrome. A delta pressure of less than 30 mmHg is the standard threshold indicating the need for emergent fasciotomy.

Question 35

A 13-year-old obese boy presents with right thigh pain and a limp. Examination reveals obligate external rotation of the right hip during flexion. Radiographs show a widened right proximal femoral physis. What is the most appropriate definitive management?

Explanation

This patient has a Slipped Capital Femoral Epiphysis (SCFE), characterized by obligate external rotation upon hip flexion. The gold standard treatment is in situ pinning with a single cannulated screw to stabilize the physis and prevent further slippage.

Question 36

A 35-year-old carpenter sustains a puncture wound to his right index finger. Two days later, he presents with severe pain and swelling. Which of the following is NOT one of Kanavel's cardinal signs of flexor tenosynovitis?

Explanation

Kanavel's four cardinal signs of flexor tenosynovitis include flexed resting posture, fusiform swelling, tenderness along the flexor sheath, and severe pain on passive extension. Erythema extending to the forearm indicates spreading cellulitis or lymphangitis.

Question 37

A 65-year-old woman undergoes a primary total hip arthroplasty. Six weeks postoperatively, she dislocates her hip while tying her shoe in a seated position. Which surgical approach was most likely utilized, and which structure's insufficiency contributes most to this specific instability?

Explanation

Dislocation while tying a shoe requires deep flexion, adduction, and internal rotation, which classically provokes posterior dislocation. The posterior approach is associated with this instability due to disruption of the posterior capsule and short external rotators.

Question 38

A 72-year-old man presents with deteriorating handwriting and frequent tripping. On exam, briskly flicking the distal phalanx of his middle finger results in spontaneous flexion of the thumb and index finger. What is this sign called, and what does it indicate?

Explanation

The Hoffmann sign is elicited by flicking the distal phalanx of the middle finger, causing reflex flexion of the thumb and index finger. It is an upper motor neuron sign indicative of cervical myelopathy, often due to spinal stenosis.

Question 39

A 4-year-old girl refuses to bear weight on her left leg. She has a temperature of 38.6°C (101.5°F), an ESR of 45 mm/hr, a serum WBC count of 14,000/mm3, and refuses to move the hip. According to the Kocher criteria, what is the probability that she has septic arthritis?

Explanation

The Kocher criteria include non-weight-bearing, temperature > 38.5°C, ESR > 40 mm/hr, and WBC > 12,000/mm3. The presence of all four criteria indicates a 99% probability of septic arthritis, warranting urgent joint aspiration.

Question 40

A 22-year-old football player sustains a hyperplantarflexion injury to his foot. Radiographs reveal widening of the space between the medial and middle cuneiforms, and a small bony avulsion in the first intermetatarsal space. What ligament is primarily injured?

Explanation

The injury described is a Lisfranc injury, involving disruption of the tarsometatarsal joint complex. The Lisfranc ligament connects the medial cuneiform to the base of the second metatarsal; the 'fleck sign' represents an avulsion fracture at its attachment.

Question 41

Which of the following fracture fixation methods relies primarily on secondary bone healing through enchondral ossification?

Explanation

Intramedullary nailing allows for relative stability and micromotion at the fracture site, promoting secondary bone healing through callus formation via enchondral ossification. Absolute stability methods rely on primary intramembranous healing.

Question 42

In a patient with late aseptic loosening of a cemented total knee arthroplasty, which biological pathway is most directly responsible for the macrophage-induced periprosthetic osteolysis?

Explanation

Particulate wear debris is phagocytosed by macrophages, causing them to release pro-inflammatory cytokines like TNF-alpha and IL-1. These cytokines stimulate the RANK/RANKL pathway, activating osteoclasts and leading to periprosthetic osteolysis.

Question 43

A 45-year-old man presents with chronic wrist pain years after a FOOSH injury. Imaging reveals a scaphoid nonunion advanced collapse (SNAC). Which joint is classically spared in the typical progression of a SNAC wrist?

Explanation

In Scaphoid Nonunion Advanced Collapse (SNAC), degenerative changes begin at the radioscaphoid joint and progress to the midcarpal joints. The radiolunate joint is classically spared due to its concentric articulation and preserved congruency.

Question 44

A 25-year-old male sustains an open tibia fracture with extensive soft tissue loss and exposed bone lacking periosteal coverage. The injury requires a free flap for coverage. What is the Gustilo-Anderson classification of this fracture?

Explanation

Gustilo-Anderson Type IIIB fractures are open fractures with extensive soft tissue damage, periosteal stripping, and bone exposure requiring a soft tissue transfer (flap) for coverage.

Question 45

A 4-month-old female with developmental dysplasia of the hip (DDH) is being treated with a Pavlik harness. During a follow-up, she exhibits decreased active knee extension on the affected side. What is the most likely cause?

Explanation

Femoral nerve palsy is a known complication of the Pavlik harness, typically caused by excessive hip hyperflexion that compresses the nerve. It presents as decreased active knee extension.

Question 46

A 19-year-old soccer player undergoes arthroscopy for a bucket-handle medial meniscus tear located in the red-white zone. What is the primary source of blood supply to the peripheral menisci?

Explanation

The peripheral vascular supply of the menisci is provided primarily by the medial and lateral inferior genicular arteries, forming a perimeniscal capillary plexus. This dictates the healing potential of peripheral repairs.

Question 47

Bone morphogenetic proteins (BMPs) play a crucial role in bone healing. Which specific signaling pathway do BMPs primarily utilize to exert their osteoinductive effect?

Explanation

BMPs belong to the Transforming Growth Factor-beta (TGF-beta) superfamily. They exert their osteoinductive effects by binding to cell surface receptors that subsequently activate the intracellular Smad signaling cascade.

Question 48

A 55-year-old poorly controlled diabetic male presents with a swollen, erythematous, warm, and painless right foot. Radiographs show early subluxation of the midfoot joints but no open ulcers. What is the most appropriate initial management?

Explanation

The patient is presenting with acute Eichenholtz Stage I Charcot arthropathy. In the absence of ulceration or systemic infection, the gold standard initial treatment is offloading and immobilization with a total contact cast.

Question 49

A 40-year-old construction worker falls from a height and sustains a thoracolumbar burst fracture. According to the Denis three-column classification, which structures must be disrupted to define this as a burst fracture rather than a simple compression fracture?

Explanation

According to the Denis classification, a burst fracture involves failure of both the anterior and middle columns under axial load. A simple compression fracture typically involves isolated failure of the anterior column.

Question 50

A 65-year-old male presents with severe back pain, fatigue, and recent onset of renal insufficiency. Radiographs show multiple 'punched-out' lytic lesions in the skull and pelvis. Which laboratory test is most diagnostic for his underlying condition?

Explanation

The triad of back pain, renal insufficiency, and punched-out lytic lesions is highly suspicious for multiple myeloma. Serum and urine protein electrophoresis (SPEP/UPEP) will detect the monoclonal protein (M-spike) confirming the diagnosis.

Question 51

A 15-year-old boy presents with worsening knee pain. Radiographs demonstrate a destructive, bone-forming lesion in the distal femoral metaphysis with a 'sunburst' periosteal reaction. Genetic analysis of this tumor is most likely to reveal a mutation in which of the following?

Explanation

Osteosarcoma is the most common primary malignant bone tumor in youths, classically presenting with a sunburst appearance. It is heavily associated with mutations in tumor suppressor genes, particularly Rb and p53 (Li-Fraumeni syndrome).

Question 52

A 32-year-old male sustains a closed comminuted tibial shaft fracture. Two hours later, he develops excruciating pain out of proportion to his injury and pain with passive stretch of his hallux. His blood pressure is 110/75 mmHg. What is the most reliable compartment pressure threshold indicating the need for emergent fasciotomy?

Explanation

Acute compartment syndrome is most accurately diagnosed using the Delta P threshold. A Delta P (diastolic blood pressure minus compartment pressure) of less than 30 mmHg requires emergent fasciotomy.

Question 53

Six weeks after a primary posterior-approach total hip arthroplasty, a 65-year-old female presents to the emergency department with a posterior dislocation that occurred while rising from a low toilet. Which of the following component malpositions is the most likely primary contributor to her instability?

Explanation

Posterior instability in total hip arthroplasty is frequently caused by retroversion of either the acetabular cup or the femoral stem. Excessive anteversion would predispose the patient to anterior dislocation.

Question 54

An obese 13-year-old boy presents with an inability to bear weight on his right leg after a minor fall. Radiographs confirm an acute, unstable slipped capital femoral epiphysis (SCFE). If the surgeon attempts a forceful, anatomic closed reduction prior to internal fixation, the patient is at highest risk for which of the following complications?

Explanation

Forceful or anatomic reduction of an unstable SCFE dramatically increases the risk of avascular necrosis. This occurs due to disruption or tensioning of the fragile posterior retinacular blood supply to the femoral head.

Question 55

During the repair of a zone II flexor tendon laceration in the index finger, a surgeon meticulously preserves specific portions of the flexor tendon sheath to prevent biomechanical failure and bowstringing. Which two annular pulleys are the most critical to preserve?

Explanation

The A2 and A4 pulleys are the most biomechanically essential structures in the flexor tendon sheath. They arise directly from the periosteum of the proximal and middle phalanges, preventing bowstringing during finger flexion.

Question 56

A surgeon treats a severely comminuted midshaft femur fracture using a locked intramedullary nail, achieving relative stability. By which physiological mechanism will this fracture primarily heal?

Explanation

Constructs that provide relative stability, such as intramedullary nails or bridge plates, promote micromotion at the fracture site. This micromotion stimulates secondary bone healing characterized by callus formation via enchondral ossification.

Question 57

A 60-year-old man presents with progressive gait clumsiness, loss of fine motor skills in his hands, and frequent falls. Physical examination reveals a positive Hoffman's sign and bilateral hyperreflexia at the patella. This clinical picture is most directly caused by compression of which of the following spinal cord structures?

Explanation

Cervical spondylotic myelopathy causes upper motor neuron signs such as hyperreflexia, spastic gait, and a positive Hoffman's sign. These upper motor neuron signs are due to compression of the descending corticospinal tracts.

Question 58

A 25-year-old male is brought to the trauma bay hemodynamically unstable following a motorcycle collision. Radiographs demonstrate an open-book pelvic fracture with a 4 cm pubic symphyseal diastasis. A pelvic circumferential compression device (binder) is applied. For maximum mechanical advantage in reducing the pelvic volume, the binder should be centered over the:

Explanation

A pelvic binder must be applied at the level of the greater trochanters to properly close the pelvic ring and reduce retroperitoneal volume. Application over the iliac crests can inadvertently worsen the diastasis of the true pelvis.

Question 59

A 12-year-old boy presents with a painful, swollen thigh. Radiographs show a permeative diaphyseal lesion in the femur with an 'onion-skin' periosteal reaction. Biopsy reveals uniform small round blue cells. Cytogenetic analysis is most likely to demonstrate which of the following translocations?

Explanation

The clinical and radiographic presentation is classic for Ewing sarcoma. This tumor is defined genetically by the t(11;22) chromosomal translocation, which results in the EWS-FLI1 fusion protein.

Question 60

A 6-week-old female infant undergoes a screening ultrasound of the hip due to a family history of developmental dysplasia of the hip (DDH). The sonographer reports an alpha angle of 50 degrees. According to the Graf classification, what does this alpha angle represent?

Explanation

In the Graf ultrasound evaluation for DDH, the alpha angle measures the concavity of the bony acetabular roof. An alpha angle less than 60 degrees (such as 50 degrees) indicates a dysplastic or shallow bony roof, typically classifying as a Graf Type II hip.

Question 61

Historically, catastrophic early failure and severe oxidative wear in ultra-high-molecular-weight polyethylene (UHMWPE) components for total knee arthroplasty were traced back to which specific manufacturing and sterilization process?

Explanation

Gamma irradiation in air generates free radicals that react with ambient oxygen over time, leading to severe oxidative degradation. This process caused catastrophic subsurface delamination and accelerated wear in early generation UHMWPE.

Question 62

A 22-year-old rugby player undergoes preoperative evaluation for recurrent anterior shoulder instability. A 3D-CT scan reveals a large Hill-Sachs lesion. Based on the 'glenoid track' concept, what specific feature categorizes his Hill-Sachs lesion as 'engaging' (off-track)?

Explanation

An 'engaging' or off-track Hill-Sachs lesion is one where the medial margin of the defect extends medial to the intact glenoid track. This allows the defect to drop over the anterior glenoid rim during abduction and external rotation.

Question 63

A 24-year-old male falls on an outstretched hand and sustains a fracture through the proximal pole of the scaphoid. He is at high risk for nonunion and avascular necrosis due to the retrograde nature of the scaphoid's blood supply. The primary vascular supply to the proximal pole is derived directly from the:

Explanation

The scaphoid receives 70-80% of its blood supply from the dorsal carpal branch of the radial artery. This vessel enters distally and provides retrograde blood flow to the proximal pole, predisposing proximal fractures to avascular necrosis.

Question 64

Articular cartilage is structurally divided into four distinct zones, each with unique cellular and biochemical properties. Which zone features the highest concentration of proteoglycans and contains chondrocytes arranged in vertical columns?

Explanation

The deep (radial) zone of articular cartilage contains the highest concentration of proteoglycans, maximizing its resistance to compressive forces. Its chondrocytes and thick collagen fibrils are uniquely arranged in vertical columns.

Question 65

A 45-year-old farmer sustains a severe open tibia fracture (Gustilo-Anderson Type IIIA) heavily contaminated with soil and manure. Standard open fracture prophylaxis includes a first-generation cephalosporin and an aminoglycoside. What specific antibiotic must be added to this patient's regimen?

Explanation

Farm-related injuries or open fractures heavily contaminated with soil are at high risk for anaerobic infections, particularly Clostridium perfringens. High-dose penicillin is added to the prophylactic antibiotic regimen to provide necessary anaerobic coverage.

Question 66

A pediatric orthopedic surgeon initiates treatment for a 2-week-old infant with an idiopathic clubfoot (talipes equinovarus) using the Ponseti casting method. Which of the following represents the correct sequential order of deformity correction?

Explanation

The Ponseti method requires sequential correction of the clubfoot deformities following the CAVE mnemonic: Cavus (corrected first by elevating the first ray), Adductus, Varus, and finally Equinus (which often requires a percutaneous Achilles tenotomy).

Question 67

A 55-year-old female undergoes open reduction and internal fixation of a dorsally comminuted distal radius fracture with a volar locking plate. Six months postoperatively, she presents with an inability to extend her thumb interphalangeal joint. The attritional rupture of this tendon is most likely due to prominent screws penetrating the:

Explanation

Volar plate screws that penetrate too far dorsally can cause attritional rupture of the extensor tendons. The Extensor Pollicis Longus (EPL) tendon, located uniquely in the third extensor compartment crossing Lister's tubercle, is the most frequently injured.

Question 68

A 28-year-old athlete tears his medial meniscus. An MRI demonstrates the tear is limited to the peripheral 10% of the meniscus, an area known for having excellent healing potential due to its vascularity. This peripheral 'red-red' zone receives its direct vascular supply from the perimeniscal capillary plexus, which originates from the:

Explanation

The peripheral 10-30% of the menisci (the red-red zone) is highly vascularized by the perimeniscal capillary plexus. This plexus is supplied primarily by branches of the medial and lateral inferior genicular arteries.

Question 69

A 62-year-old male presents with persistent mid-back pain, worsening fatigue, and laboratory evidence of hypercalcemia and anemia. Radiographs demonstrate a 'punched-out' lytic lesion in the L3 vertebral body. Serum protein electrophoresis shows a monoclonal M-spike. This primary bone lesion represents a malignant proliferation of which cell type?

Explanation

The patient's presentation of CRAB symptoms (hyperCalcemia, Renal failure, Anemia, Bone lytic lesions) with an M-spike is diagnostic of multiple myeloma. Multiple myeloma is a malignant proliferation of plasma cells and is the most common primary bone malignancy in adults.

Question 70

Polymethylmethacrylate (PMMA) bone cement is widely utilized in cemented total joint arthroplasty. By what primary mechanism does PMMA secure the metallic prosthesis to the host bone?

Explanation

PMMA bone cement acts strictly as a mechanical grout, not an adhesive. It achieves fixation by physically micro-interlocking with the porous spaces of cancellous bone and the roughened surface of the metallic implant, without any true chemical or biological bonding.

Question 71

A 6-year-old boy presents to the emergency department following a fall from monkey bars. Radiographs reveal an extension-type Gartland III supracondylar humerus fracture. After closed reduction and percutaneous pinning, the patient's radial pulse is absent, but the hand is pink, warm, and has a capillary refill time of less than 2 seconds. What is the most appropriate next step in management?

Explanation

A pulseless, pink, and well-perfused hand following reduction and pinning of a supracondylar humerus fracture should be observed, as collateral circulation is adequate. Arterial exploration is strictly indicated only if the hand is pulseless, pale, and poorly perfused (ischemic) after reduction.

Question 72

A 60-year-old male with a metal-on-metal total hip arthroplasty performed 8 years ago presents with worsening groin pain and a palpable mass. Radiographs show well-fixed implants with no osteolysis. Joint aspiration yields fluid with a normal leukocyte count and negative cultures. MRI reveals a large, solid-cystic pseudotumor. Which of the following is the most likely diagnosis?

Explanation

Metal-on-metal total hip arthroplasties can fail due to an adverse local tissue reaction (ALTR) or aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL). This immune reaction to metal ions presents with pain, sterile effusions, and pseudotumors, often requiring revision surgery.

Question 73

A 25-year-old male sustains a high-energy Pauwels type III femoral neck fracture. He undergoes fixation with a dynamic hip screw and a derotational screw. Which of the following biomechanical characteristics most strongly predisposes this specific fracture pattern to failure?

Explanation

Pauwels type III femoral neck fractures have a vertical fracture line (angle > 50 degrees). This orientation subjects the fracture site to massive shear forces rather than compression, greatly predisposing it to varus collapse and nonunion.

Question 74

A 15-year-old boy presents with knee pain. Radiographs reveal a mixed lytic and sclerotic lesion in the distal femoral metaphysis with periosteal elevation forming a Codman triangle. A biopsy shows pleomorphic spindle cells producing immature osteoid. Which of the following genetic alterations is most highly associated with this pathology?

Explanation

The clinical and histological presentation is classic for conventional osteosarcoma. This malignant bone tumor is heavily associated with mutations in the tumor suppressor genes RB1 and TP53, whereas t(11;22) is characteristic of Ewing sarcoma.

Question 75

A 22-year-old female collegiate soccer player undergoes anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) autograft. Compared to a hamstring autograft, the BPTB autograft is most closely associated with an increased incidence of which of the following postoperative complications?

Explanation

Bone-patellar tendon-bone (BPTB) autografts provide excellent structural stability but are associated with a higher incidence of donor site morbidity, specifically anterior knee pain and kneeling pain, compared to hamstring autografts.

Question 76

A 35-year-old male presents with chronic radial-sided wrist pain 2 years after an untreated fall on an outstretched hand. Radiographs demonstrate a scaphoid nonunion. In the progression of Scaphoid Nonunion Advanced Collapse (SNAC), which joint is characteristically the first to develop degenerative arthritic changes?

Explanation

In Scaphoid Nonunion Advanced Collapse (SNAC), the earliest arthritic change (Stage 1) occurs at the articulation between the radial styloid and the distal pole of the scaphoid. The radiolunate joint is typically spared entirely throughout the disease process.

Question 77

A 65-year-old female with a high risk of osteoporotic fractures is initiated on denosumab therapy. Which of the following best describes the specific mechanism of action of this medication?

Explanation

Denosumab is a monoclonal antibody that targets and binds to RANKL (Receptor Activator of Nuclear factor Kappa-B Ligand). By blocking RANKL from binding to its receptor on osteoclasts, it effectively inhibits osteoclast activation, function, and survival.

Question 78

A 65-year-old male presents with progressive clumsiness of his hands, difficulty buttoning his shirt, and a broad-based, unsteady gait. MRI of the cervical spine demonstrates severe stenosis at C5-C6 with T2 signal hyperintensity and T1 signal hypointensity within the spinal cord. Which of the following findings is the strongest predictor of poor neurological recovery following surgical decompression?

Explanation

In patients with cervical spondylotic myelopathy, T1 signal hypointensity within the spinal cord on MRI suggests permanent cystic cord changes or myelomalacia. This specific neuroimaging finding is a strong, independent predictor of poorer clinical recovery after decompression.

Question 79

A 13-year-old obese male presents with a 3-week history of right-sided groin pain and an antalgic gait. Physical examination reveals an obligatory external rotation of the right hip during passive hip flexion. Radiographs confirm a mild, stable slipped capital femoral epiphysis (SCFE). What is the most appropriate definitive management?

Explanation

The gold standard treatment for a stable slipped capital femoral epiphysis (SCFE) is in situ fixation using a single partially threaded cannulated screw. Attempting a closed reduction is contraindicated as it severely increases the risk of avascular necrosis of the femoral head.

Question 80

A 24-year-old football player sustains a hyperplantarflexion injury to his midfoot. Radiographs demonstrate widening of the space between the medial cuneiform and the base of the second metatarsal, accompanied by a small bony "fleck sign". The ruptured ligament responsible for this pathognomonic finding connects which two osseous structures?

Explanation

The Lisfranc ligament is an intra-articular ligament that extends from the lateral aspect of the medial cuneiform to the medial base of the second metatarsal. Avulsion of this critical stabilizing structure often produces the pathognomonic "fleck sign" on AP foot radiographs.

Self Assessment Examination Adult S Review | Dr Hutaif - ...

Free Orthopedics Review | Dr Hutaif General Orthopedics -...

Key Takeaway

Free Orthopedics Review | Dr Hutaif General Orthopedics -...

Chapter Index