ABOS Part I & OITE Orthopedic Review: Spine & Shoulder

Question 1

A 65-year-old diabetic male presents with insidious onset of back pain, low-grade fever, and progressive bilateral leg weakness over 2 weeks. On examination, he has a T10 sensory level and 3/5 motor strength in both lower extremities. Initial plain radiographs of the thoracic spine are unremarkable. Which of the following is the most appropriate initial diagnostic step?

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Explanation

Correct Answer: D

MRI with gadolinium is the gold standard for diagnosing spinal epidural abscess (SEA), demonstrating the collection, degree of spinal cord compression, and identifying associated osteomyelitis or discitis. Given the progressive neurological deficit and suspicion of infection, urgent definitive imaging is crucial. Plain radiographs are insensitive in early disease. CT myelogram is less sensitive for soft tissue detail than MRI and involves radiation and contrast injection into the CSF. Lumbar puncture is generally contraindicated in suspected SEA due to the risk of neurological deterioration or meningitis. EMG is for peripheral nerve pathology. Corticosteroids are contraindicated before definitive diagnosis and debridement in bacterial infections.

Question 2

A patient undergoing hemodialysis develops severe cervical spine pain, fevers, and rapidly progressive quadriparesis. Blood cultures are pending. Given the patient's history, which organism is most likely responsible for a presumed spinal epidural abscess?

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Explanation

Correct Answer: C

Staphylococcus aureus is the most common pathogen responsible for spinal epidural abscesses (SEA), accounting for 60-90% of cases. Methicillin-resistant S. aureus (MRSA) is particularly prevalent in patients with healthcare-associated risk factors such as hemodialysis, IV drug use, recent surgery, or indwelling catheters. While E. coli and Pseudomonas can occur, and Candida in immunocompromised hosts, S. aureus remains the dominant pathogen, especially in the context of healthcare exposure. Mycobacterium tuberculosis typically presents with a more chronic course.

Question 3

A 70-year-old male with a known C6-C7 spinal epidural abscess presents with acute urinary retention and rapidly progressive weakness in his lower extremities (motor strength 2/5). He has been on intravenous antibiotics for 48 hours without clinical improvement. What is the most appropriate next step?

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Explanation

Correct Answer: B

Urgent surgical decompression is indicated for spinal epidural abscesses with progressive neurological deficits (such as new-onset urinary retention, rapidly worsening weakness) or failure of appropriate medical management to prevent irreversible neurological damage. Continuing antibiotics alone is insufficient. Adding rifampin may be part of an antibiotic strategy but does not address acute mechanical compression. Percutaneous aspiration may be considered for diagnosis or small, stable collections but not for acute, progressive deficits with neurological compromise. Steroids are generally contraindicated as they can mask symptoms, impair host immunity in bacterial infections, and are not a definitive treatment for pus collection.

Question 4

On MRI, a spinal epidural abscess typically appears as what on T2-weighted images?

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Explanation

Correct Answer: C

Spinal epidural abscesses typically appear hyperintense on T2-weighted images due to the high fluid content of pus. They are often surrounded by a peripheral hypointense rim (representing granulation tissue or inflammatory changes) that shows significant enhancement after gadolinium administration. Homogenously hypointense or isointense to CSF are incorrect. Hyperintense without significant contrast enhancement would be atypical for an active abscess, which typically enhances due to inflammation and vascularity of the capsule.

Question 5

Which of the following conditions is LEAST likely to mimic a spinal epidural abscess on initial presentation, considering its typical clinical picture?

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Explanation

Correct Answer: E

A spinal epidural abscess (SEA) commonly presents with back pain, fever, and neurological deficits. Acute disc herniation, spinal cord tumors, and transverse myelitis can all present with similar neurological deficits and pain, making them strong mimics. Guillain-Barré Syndrome (GBS) can cause rapidly ascending paralysis, mimicking severe neurological compromise, though fever, focal spinal pain, and a distinct sensory level are less typical for GBS, which presents with areflexia. A simple osteoporotic vertebral compression fracture, while causing back pain, typically does not present with fever or progressive neurological deficits unless there's associated cord compression from retropulsion or epidural hematoma, which would be atypical for the initial presentation of an uncomplicated osteoporotic fracture. Thus, a simple compression fracture is the least likely to mimic the full clinical picture of an SEA.

Question 6

What is the typical recommended duration of intravenous antibiotic therapy for an uncomplicated pyogenic spinal epidural abscess managed non-surgically, assuming cultures are positive for a sensitive organism?

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Explanation

Correct Answer: C

For pyogenic spinal epidural abscesses (SEA), especially those managed non-surgically or those that have undergone successful debridement, a prolonged course of antibiotics is crucial to prevent recurrence and ensure eradication. A typical duration is 6-8 weeks of intravenous antibiotics, often followed by a transition to oral antibiotics for a similar duration, or sometimes 8-12 weeks total with IV transitioning to oral. The total duration depends on the pathogen, host factors, and resolution of inflammatory markers, but 6-8 weeks IV is a standard starting point for uncomplicated cases. 2-4 weeks is generally too short for eradication of established spinal infection, while 3-6 months is more typical for complicated osteomyelitis or prosthetic joint infections.

Question 7

A 45-year-old male presents with right flank pain, limping, and an inability to fully extend his right hip. He has a history of Crohn's disease. On examination, he has tenderness in the right iliac fossa and a positive psoas sign. What is the most appropriate imaging study to confirm the diagnosis and assess for a potential spinal origin?

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Explanation

Correct Answer: C

While CT abdomen/pelvis with IV contrast is excellent for visualizing psoas abscesses, MRI of the lumbar spine and pelvis with contrast offers superior soft tissue resolution, allowing for better identification of the primary source (e.g., discitis, vertebral osteomyelitis), the extent of the abscess, and any intraspinal involvement. Given that psoas abscesses can often originate from spinal infections (or in Crohn's disease, directly from the bowel), MRI provides a more comprehensive assessment of both spinal and psoas pathology. The psoas sign is classic for psoas irritation/abscess.

Question 8

A patient from an endemic area presents with chronic back pain, night sweats, and weight loss. Imaging reveals destruction of multiple contiguous vertebral bodies with associated large paraspinal abscesses and severe kyphotic deformity. Which pathogen is most likely responsible?

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Explanation

Correct Answer: C

This clinical presentation, including chronic symptoms, systemic signs (night sweats, weight loss), destruction of multiple contiguous vertebral bodies (often with relative disc sparing initially but progressing to disc and multiple levels), large paraspinal 'cold' abscesses, and progressive kyphotic deformity (Pott's kyphosis), is classic for spinal tuberculosis (Pott's disease). It is more common in endemic areas and immunocompromised individuals. The other pathogens typically cause pyogenic infections with a more acute course.

Question 9

Which of the following criteria would NOT typically favor non-operative management of a spinal epidural abscess?

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Explanation

Correct Answer: E

Progressive neurological deficit, especially despite appropriate antibiotic therapy, is a strong absolute indication for urgent surgical decompression of a spinal epidural abscess. This represents failure of medical management and an increasing threat of irreversible neurological damage. The other options (no or minimal neurological deficit, small abscess, responsive infection, and severe comorbidities precluding surgery) are factors that would favor an attempt at non-operative management with close monitoring.

Question 10

A 50-year-old IV drug user presents with fever, severe T12 back pain, and new-onset paraparesis. Pending blood cultures and biopsy results, what is the most appropriate empiric intravenous antibiotic regimen?

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Explanation

Correct Answer: A

In a patient with risk factors for both MRSA (IV drug user) and Gram-negative bacteria (potentially via hematogenous spread or urinary source), empiric broad-spectrum coverage is essential. Vancomycin provides excellent coverage against MRSA, while a third-generation cephalosporin like Ceftriaxone provides good coverage against Gram-negative organisms, making this a common and appropriate empiric combination. Ciprofloxacin and Rifampin would be used for specific organisms (e.g., Cipro for Pseudomonas, Rifampin in combo for S. aureus after susceptibility). Penicillin G is too narrow. Doxycycline/Metronidazole targets anaerobic and atypical bacteria. Fluconazole/Amphotericin B are for fungal infections.

Question 11

When initiating your answer to an oral examination question about a patient presenting with shoulder pain, what is the most crucial element to establish first to demonstrate a systematic approach?

Explanation

Correct Answer: D

While age, mechanism, and duration are vital historical elements, starting with a comprehensive patient history, including relevant medical comorbidities, medications, allergies, social history, and previous treatments, establishes a foundational understanding. This holistic approach demonstrates a thorough, patient-centered, and systematic thought process, which is highly valued in oral examinations. Jumping to a diagnosis or differential without context is premature.

Question 12

An examiner asks you to discuss the differential diagnosis for a 55-year-old active male presenting with atraumatic, insidious onset shoulder pain, worse with overhead activities. Which of the following conditions is LEAST likely to be a primary consideration in this demographic?

Explanation

Correct Answer: E

Recurrent anterior glenohumeral instability, while possible, is far less common to present de novo as atraumatic, insidious onset pain in a 55-year-old male compared to younger, more active populations. Rotator cuff pathology (tendinopathy/tear), subacromial impingement, glenohumeral osteoarthritis, and adhesive capsulitis are all very common causes of atraumatic, insidious shoulder pain in this age group and should be primary considerations.

Question 13

During the physical examination portion of your oral answer, the examiner asks how you would assess for a subscapularis tear. Which test is considered the most specific for isolated subscapularis pathology?

Explanation

Correct Answer: D

The Lift-Off Test (Gerber's Test) is specifically designed to assess the integrity and strength of the subscapularis muscle. The patient places their hand behind their back, and the examiner asks them to lift it off their back. Inability to do so, or weakness compared to the contralateral side, suggests subscapularis pathology. The External Rotation Lag Sign can also indicate subscapularis dysfunction but is less specific for isolated tears. Empty Can and Jobe's tests assess supraspinatus, and Speed's test assesses biceps/SLAP.

Question 14

An examiner asks you about imaging for a suspected rotator cuff tear. For initial evaluation, which imaging modality is generally preferred due to its balance of cost-effectiveness, accessibility, and diagnostic accuracy?

Explanation

Correct Answer: C

While plain radiographs are essential for bone assessment and initial screening, and diagnostic ultrasound can be highly accurate in experienced hands, MRI is considered the gold standard for soft tissue evaluation of the shoulder, including rotator cuff tears. It provides excellent detail of the tendons, labrum, capsule, and bone marrow edema. CT scans are superior for bony detail but poor for soft tissue, and CT arthrograms are typically reserved for specific instability or labral questions where MRI might be equivocal.

Question 15

You are discussing a case of suspected adhesive capsulitis with an examiner. Which of the following physical examination findings is most characteristic and crucial to highlight?

Explanation

Correct Answer: C

The hallmark of adhesive capsulitis is a significant global restriction of both active and passive range of motion, with passive external rotation being the most consistently and severely limited motion. A loss of passive external rotation often exceeding 50% compared to the unaffected side is highly characteristic. Neer and Hawkins signs are indicative of impingement, apprehension for instability, and resisted flexion for biceps/impingement.

Question 16

When outlining your management plan for a patient with acute calcific tendinitis, what is the most appropriate initial non-operative treatment strategy to propose?

Explanation

Correct Answer: C

Acute calcific tendinitis can be excruciating. A comprehensive initial non-operative strategy typically includes high-dose oral NSAIDs for pain and inflammation, rest from aggravating activities, and physical therapy with gentle range of motion exercises to maintain mobility. While a subacromial corticosteroid injection can provide rapid pain relief and is often considered, option B specifies a 'glenohumeral joint' injection, which is incorrect for subacromial calcific tendinitis. Therefore, a structured regimen of NSAIDs, rest, and PT is the most appropriate initial strategy among the given choices. Surgical excision is reserved for refractory cases, and ESWT is a secondary option. Manipulation is not indicated.

Question 17

An examiner probes your understanding of rotator cuff repair indications. Which factor is generally considered a strong indication for surgical repair of an acute, traumatic full-thickness rotator cuff tear in an otherwise healthy, active patient?

Explanation

Correct Answer: C

For an acute, traumatic full-thickness rotator cuff tear in an otherwise healthy, active patient, surgical repair is often indicated early to optimize healing potential and prevent retraction. However, the question asks for a strong indication for surgical repair, which often implies a failure of initial non-operative measures or a clear functional deficit. Significant functional impairment that persists despite a trial of 6-12 weeks of structured non-operative management (which might be attempted even for some acute tears, or is standard for chronic tears) is a universally strong indication for surgical repair. While acute traumatic tears in active patients are often repaired sooner, option C represents a robust and widely accepted indication for surgical intervention when conservative measures have proven insufficient. Age over 70 is a relative contraindication, chronic degenerative tears without significant deficit may be observed, and tear size alone is not always the sole indicator. Associated glenohumeral osteoarthritis influences the type of surgery, not necessarily the indication for rotator cuff repair itself.

Question 18

When discussing the expected outcome following an arthroscopic Bankart repair for recurrent anterior shoulder instability, what complication is crucial to mention to the examiner as a potential risk, particularly regarding range of motion?

Explanation

Correct Answer: C

Post-operative stiffness, or iatrogenic adhesive capsulitis, is a recognized complication after arthroscopic instability repair, especially if immobilization is prolonged or rehabilitation is too aggressive initially, or if there's an over-tightening of the capsule. Axillary nerve palsy is rare but serious. Deltoid detachment is more relevant for open approaches, and AVN is extremely rare for Bankart repair. Hardware impingement is possible but less common than stiffness.

Question 19

You are asked to describe the rehabilitation principles following an arthroscopic rotator cuff repair. What is the primary goal during the initial phase (0-6 weeks post-op)?

Explanation

Correct Answer: C

The initial phase (0-6 weeks) after rotator cuff repair is critical for protecting the healing tendon. The primary goals are to protect the repair site from excessive stress (often with immobilization), manage pain and inflammation, and gradually restore passive range of motion within protected arcs. Aggressive active motion or strengthening is contraindicated as it can jeopardize the repair. Full active ROM and return to sport are later phase goals.

Question 20

An examiner presents a radiograph showing significant glenohumeral osteoarthritis in a 70-year-old patient with intact rotator cuff. When discussing surgical options, what would be your primary recommendation?

Explanation

Correct Answer: D

For primary glenohumeral osteoarthritis with an intact rotator cuff, Total Shoulder Arthroplasty (TSA) is the gold standard surgical treatment, providing excellent pain relief and restoration of function. RTSA is indicated for rotator cuff deficient arthropathy. Hemiarthroplasty is considered for younger, active patients, those with inflammatory arthritis, or when the glenoid is irreparable. Arthroscopic debridement is generally palliative for early OA. Arthrodesis is a salvage procedure.

Question 21

A 22-year-old male presents with recurrent anterior shoulder instability following an initial dislocation during a rugby match. Advanced imaging reveals 25% anterior glenoid bone loss and an engaging Hill-Sachs lesion. Which of the following is the most appropriate definitive surgical management?

Explanation

The Latarjet procedure is indicated for patients with recurrent anterior shoulder instability and critical glenoid bone loss (typically greater than 20-25%). Soft tissue stabilization alone (Bankart repair) carries an unacceptably high failure rate in this setting.

Question 22

During a neurological examination of a 68-year-old male with suspected cervical spondylotic myelopathy, the examiner strikes the brachioradialis tendon. The patient responds with diminished elbow flexion, but exhibits spontaneous finger flexion and wrist extension. This finding is known as the inverted brachioradialis reflex. What level of spinal cord pathology does this most accurately suggest?

Explanation

The inverted brachioradialis reflex localizes to a C5-C6 spinal cord lesion. It indicates a lower motor neuron lesion at C5 (absent elbow flexion) and an upper motor neuron lesion at C6 (hyperactive finger flexion/wrist extension).

Question 23

A 72-year-old female with massive, irreparable rotator cuff tear and pseudoparalysis is undergoing a reverse total shoulder arthroplasty (RTSA). During component positioning, which of the following modifications is most effective at decreasing the risk of postoperative scapular notching?

Explanation

Scapular notching is a common complication of RTSA caused by impingement of the humeral component against the inferior scapular neck. Inferior positioning and inferior tilt of the baseplate, along with lateralization, significantly reduce this risk.

Question 24

A 14-year-old gymnast presents with persistent lower back pain exacerbated by extension. Radiographs reveal an L5-S1 isthmic spondylolisthesis. If this patient were to develop radicular symptoms due to the pseudarthrosis tissue in the pars defect, which nerve root is most likely to be compressed?

Explanation

In an L5-S1 isthmic spondylolisthesis, hypertrophic fibrocartilaginous tissue at the pars interarticularis defect classically compresses the exiting L5 nerve root within the neural foramen.

Question 25

A 45-year-old female sustains a 4-part proximal humerus fracture. According to the Hertel criteria, which of the following radiographic findings is the most reliable predictor of an intact blood supply to the humeral head, thereby decreasing the risk of avascular necrosis?

Explanation

Hertel et al. demonstrated that a medial hinge length of >8 mm and an intact medial calcar attached to the articular segment are the strongest predictors of preserved humeral head perfusion in proximal humerus fractures.

Question 26

A 55-year-old male with a long-standing history of Ankylosing Spondylitis presents to the emergency department with severe neck pain after a minor ground-level fall. Initial plain radiographs of the cervical spine appear normal without obvious fracture. What is the most appropriate next step in management?

Explanation

Patients with Ankylosing Spondylitis are at high risk for highly unstable, occult spinal fractures even after minor trauma. Due to altered bone density and overlapping anatomy on plain films, a CT scan is mandatory for proper evaluation.

Question 27

A 30-year-old male presents with dull aching pain in his right shoulder and difficulty lifting overhead. On examination, having the patient perform a wall push-up demonstrates pronounced prominence of the medial border of the scapula. An injury to which of the following nerves is the most likely cause?

Explanation

Prominence of the medial border of the scapula with forward elevation or wall push-ups indicates medial winging, caused by paralysis of the serratus anterior muscle which is innervated by the long thoracic nerve.

Question 28

A 40-year-old male presents with acute onset of bilateral sciatica, saddle anesthesia, and urinary retention. A post-void residual is measured at 350 mL. MRI confirms a massive L4-L5 central disc herniation. To maximize the likelihood of recovery of bladder sphincter function, surgical decompression should ideally be performed within what time frame?

Explanation

Cauda equina syndrome is a surgical emergency. The current literature demonstrates that surgical decompression performed within 24 to 48 hours of symptom onset provides the greatest potential for recovery of bladder and bowel function.

Question 29

A 55-year-old male laborer presents with chronic right shoulder pain and weakness. Examination reveals a positive Hornblower's sign and severe weakness in external rotation. MRI demonstrates an isolated, massive, and irreparable tear of the posterosuperior rotator cuff with advanced fatty infiltration. Which of the following tendon transfers is most appropriate to restore external rotation?

Explanation

A latissimus dorsi (or lower trapezius) tendon transfer is indicated to restore active external rotation and forward elevation in younger, active patients with massive, irreparable posterosuperior rotator cuff tears.

Question 30

A 25-year-old female presents after a motor vehicle accident with an isolated T12 burst fracture. She is neurologically intact. MRI demonstrates definitive disruption of the posterior ligamentous complex (PLC). According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the recommended treatment?

Explanation

The TLICS score assigns 2 points for a burst fracture, 3 points for PLC disruption, and 0 points for being neurologically intact, totaling 5 points. A score of 5 or greater indicates surgical stabilization, typically via posterior spinal fusion.

Question 31

A 22-year-old baseball pitcher undergoes arthroscopic repair of a Type II SLAP tear. Postoperatively, the patient develops profound stiffness in the shoulder. Placing arthroscopic knots posterior to the biceps anchor during the repair is most likely to restrict which specific arc of motion?

Explanation

Tying knots posterior to the biceps anchor during a SLAP repair can inadvertently tether the posterior labrum and capsule. This predominantly restricts external rotation in abduction, heavily impairing a throwing athlete's performance.

Question 32

A 45-year-old male complains of neck pain radiating into his left arm. Physical examination reveals weakness in elbow extension, diminished triceps reflex, and paresthesias affecting the dorsal aspect of the middle finger. These clinical findings are most consistent with a disc herniation at which of the following cervical levels?

Explanation

The patient exhibits signs of a C7 radiculopathy (triceps weakness, middle finger numbness, absent triceps reflex). In the cervical spine, the exiting nerve root corresponds to the lower vertebral body of the disc segment, making C6-C7 the responsible level.

Question 33

A 35-year-old professional volleyball player presents with isolated weakness in shoulder external rotation. Supraspinatus strength is normal on empty-can testing. Inspection reveals prominent atrophy limited to the infraspinatus fossa. Where is the most likely anatomic location of nerve entrapment?

Explanation

The suprascapular nerve innervates both the supraspinatus and infraspinatus. Entrapment at the spinoglenoid notch affects only the branch to the infraspinatus, causing isolated external rotation weakness and isolated infraspinatus atrophy.

Question 34

A 35-year-old male sustains a transverse Type II odontoid fracture with 15% anterior displacement following a diving accident. He is neurologically intact. Which of the following treatments provides the highest rate of fusion while preserving maximal C1-C2 rotatory motion?

Explanation

Anterior odontoid screw fixation is ideal for young patients with a transverse Type II fracture pattern as it provides direct osteosynthesis while preserving the normal C1-C2 rotation lost in posterior fusion techniques.

Question 35

A 28-year-old male sustains a Grade III acromioclavicular (AC) joint separation. If non-operative management fails and reconstruction is required, the surgeon must focus on reconstructing the primary stabilizers to superior translation of the distal clavicle. Which structures are these?

Explanation

The coracoclavicular (CC) ligaments, consisting of the conoid and trapezoid, act as the primary stabilizers against superior translation of the distal clavicle. The AC ligaments primarily restrict anterior-posterior translation.

Question 36

A 50-year-old male presents with severe severe right anterior thigh pain and quadriceps weakness. The patellar reflex is absent on the right. MRI demonstrates a large, far-lateral (extraforaminal) disc herniation at the L3-L4 level. Which nerve root is most likely compressed?

Explanation

In the lumbar spine, a far-lateral (extraforaminal) disc herniation compresses the exiting nerve root at that level. Therefore, an L3-L4 far-lateral disc herniation compresses the L3 nerve root, whereas a central/paracentral herniation would compress the traversing L4 root.

Question 37

A 50-year-old male sustains a forced external rotation injury to his shoulder. He presents with increased passive external rotation and a positive belly-press test. MRI confirms an isolated, full-thickness retraction of the subscapularis tendon. Which associated anatomic structure is at the highest risk of concomitant instability or injury?

Explanation

The subscapularis tendon insertion forms a critical portion of the biceps sling (transverse humeral ligament complex). A full-thickness, retracted subscapularis tear frequently leads to medial subluxation or dislocation of the long head of the biceps tendon.

Question 38

A 16-year-old male presents with thoracic back pain and cosmetic concerns about his posture. Lateral radiographs reveal anterior wedging of greater than 5 degrees in three consecutive vertebrae, confirming Scheuermann's kyphosis. Operative intervention via spinal fusion is most commonly indicated when the kyphotic deformity exceeds which of the following angles?

Explanation

Surgical management of Scheuermann's kyphosis is typically reserved for skeletally mature patients with severe pain or deformity, generally accepted as a kyphotic curve exceeding 70 to 75 degrees.

Question 39

A 21-year-old collegiate rugby player presents with recurrent anterior shoulder instability. A CT scan of the shoulder reveals 25% anterior glenoid bone loss. Which of the following is the most appropriate surgical intervention?

Explanation

The Latarjet procedure is indicated for recurrent anterior shoulder instability in the setting of critical anterior glenoid bone loss (typically >20-25%). Arthroscopic soft tissue stabilization has an unacceptably high failure rate in patients with significant bone loss.

Question 40

A 45-year-old male complains of severe left-sided radiating leg pain. Magnetic resonance imaging demonstrates an extraforaminal (far-lateral) disc herniation at the L4-L5 level. Which nerve root is most likely compressed?

Explanation

In the lumbar spine, an extraforaminal (far-lateral) disc herniation compresses the exiting nerve root at the same level. Therefore, an L4-L5 extraforaminal herniation compresses the exiting L4 nerve root.

Question 41

A 35-year-old female undergoes a posterior cervical lymph node biopsy. Postoperatively, she complains of shoulder weakness and is noted to have lateral winging of the scapula with the shoulder drooping. Which nerve was most likely injured, and which muscle is primarily affected?

Explanation

Injury to the spinal accessory nerve (often during posterior triangle neck biopsies) causes trapezius palsy, leading to lateral winging of the scapula. Long thoracic nerve injury causes medial winging due to serratus anterior weakness.

Question 42

A 68-year-old male with a long-standing history of ankylosing spondylitis sustains a low-energy fall. He complains of new-onset lower cervical pain but is neurologically intact. Plain radiographs of the cervical spine show no obvious fracture. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis are at extremely high risk for highly unstable spinal fractures even from minor trauma. Given the difficulty in interpreting plain radiographs in these patients, a CT scan of the entire cervical spine is mandatory to rule out occult fractures.

Question 43

A 30-year-old competitive weightlifter feels a sudden "pop" in his anterior shoulder while performing a heavy bench press. He presents with ecchymosis and loss of the anterior axillary fold. If surgical repair is pursued, which of the following describes the most common anatomic location of the tear?

Explanation

Pectoralis major ruptures most commonly occur during eccentric loading, such as the bench press. The majority of these injuries involve avulsion of the sternal head from its insertion on the humerus.

Question 44

A 22-year-old restrained passenger in a motor vehicle collision sustains a flexion-distraction injury (Chance fracture) at L2. Which of the following associated injuries must be aggressively ruled out?

Explanation

Flexion-distraction injuries (Chance fractures) of the thoracolumbar spine are highly associated with concurrent intra-abdominal injuries, particularly hollow viscus (e.g., bowel) tears. A high index of suspicion and appropriate general surgery evaluation are required.

Question 45

A 40-year-old male presents with a locked, internally rotated right shoulder following a generalized seizure. Imaging confirms a posterior shoulder dislocation with a 30% reverse Hill-Sachs lesion. Which of the following is the most appropriate surgical management?

Explanation

A reverse Hill-Sachs lesion is an impaction fracture of the anteromedial humeral head following a posterior dislocation. For defects between 20% and 40%, transfer of the lesser tuberosity or subscapularis tendon into the defect (McLaughlin procedure) is the preferred treatment.

Question 46

A 70-year-old female with degenerative lumbar spinal stenosis complains of bilateral lower extremity pain and cramping with ambulation. Which of the following historical findings best differentiates her neurogenic claudication from vascular claudication?

Explanation

Neurogenic claudication is typically relieved by lumbar flexion and exacerbated by extension. Therefore, patients tolerate walking uphill (which induces lumbar flexion) much better than walking downhill (which induces lumbar extension).

Question 47

A 70-year-old male with a chronic massive rotator cuff tear presents with pseudoparalysis and severe glenohumeral osteoarthritis. Radiographs show superior migration of the humeral head with acetabularization of the coracoacromial arch (Hamada Grade 3). Which of the following is the most appropriate definitive surgical management?

Explanation

Reverse total shoulder arthroplasty (RTSA) is the treatment of choice for rotator cuff arthropathy with pseudoparalysis. Anatomic TSA is contraindicated due to the deficient rotator cuff, which would lead to superior eccentric wear and early glenoid loosening.

Question 48

A 65-year-old female with a long history of rheumatoid arthritis presents with progressive hand clumsiness and hyperreflexia. Radiographs reveal atlantoaxial instability. Which of the following radiographic measurements is the most reliable predictor of neurologic recovery following cervical fusion?

Explanation

The posterior atlantodental interval (PADI) directly measures the space available for the spinal cord. A PADI of less than 14 mm is a critical threshold and the most reliable predictor of potential neurologic recovery in rheumatoid atlantoaxial subluxation.

Question 49

A 22-year-old male collegiate football player presents with recurrent anterior shoulder instability. A 3D CT scan of the shoulder reveals 25% anterior glenoid bone loss. Which of the following surgical interventions is most appropriate to minimize recurrence?

Explanation

In collision athletes with critical anterior glenoid bone loss (>20-25%), an arthroscopic Bankart repair has an unacceptably high failure rate. The Latarjet procedure (coracoid transfer) addresses the bony defect and provides a sling effect to stabilize the joint.

Question 50

A 35-year-old female is involved in a high-speed motor vehicle collision while wearing only a lap belt. She sustains a T12 flexion-distraction injury (Chance fracture). During her trauma evaluation, she is at highest risk for which of the following concomitant injuries?

Explanation

Chance fractures (flexion-distraction injuries of the spine) are highly associated with lap belt use in motor vehicle accidents. They carry a very high incidence (up to 40-50%) of concurrent intra-abdominal injuries, particularly hollow viscus lacerations.

Question 51

A 28-year-old bodybuilder feels a sudden pop and tearing sensation in his anterior chest wall while performing a heavy eccentric bench press. On examination, he has loss of the anterior axillary fold and weakness in internal rotation. If surgical repair is performed, the tendon should be reattached to which of the following anatomic locations?

Explanation

The patient has sustained a pectoralis major tendon rupture, which typically occurs during the eccentric phase of a bench press. The native footprint of the pectoralis major tendon is located on the lateral lip of the bicipital groove.

Question 52

A 65-year-old female presents with severe neurogenic claudication and low back pain. MRI demonstrates severe L4-L5 central canal stenosis. Weight-bearing radiographs show a Grade I degenerative spondylolisthesis at L4-L5 that increases on flexion views. Which of the following is the most appropriate surgical treatment?

Explanation

For patients with symptomatic spinal stenosis and associated dynamic instability or degenerative spondylolisthesis, decompression alone has a high failure rate. Laminectomy combined with an instrumented fusion provides superior long-term clinical outcomes.

Question 53

A 72-year-old female presents with severe right shoulder pain, limited active elevation to 45 degrees, and an intact deltoid. Radiographs reveal severe glenohumeral osteoarthritis with superior migration of the humeral head. An MRI confirms a massive, retracted, and irreducible tear of the supraspinatus and infraspinatus tendons with grade 4 fatty infiltration. What is the most appropriate surgical intervention?

Explanation

Reverse total shoulder arthroplasty relies on the deltoid to elevate the arm, moving the center of rotation medially and inferiorly. It is the treatment of choice for patients with cuff tear arthropathy and pseudoparalysis.

Question 54

A 22-year-old collegiate rugby player presents with recurrent anterior shoulder instability. A 3D CT scan reveals 27% anterior glenoid bone loss. An MRI confirms a concomitant Hill-Sachs lesion, and the lesion is determined to be "off-track." Which of the following is the most appropriate definitive surgical management?

Explanation

In the setting of significant anterior glenoid bone loss (>20-25%), isolated soft tissue repairs have an unacceptably high failure rate. A coracoid transfer (Latarjet) reconstructs the bony defect and provides a dynamic sling via the conjoint tendon.

Question 55

A 60-year-old male presents with bilateral hand clumsiness, frequent dropping of objects, and a broad-based, unsteady gait. Physical exam reveals a positive Hoffman's sign bilaterally and hyperreflexia in the lower extremities. MRI reveals continuous ossification of the posterior longitudinal ligament (OPLL) from C3 to C6, causing severe ventral cord compression. The cervical spine maintains normal lordosis. What is the most appropriate surgical approach?

Explanation

Posterior laminectomy and fusion is the preferred approach for multi-level OPLL (>3 levels) in a lordotic spine. Anterior approaches for extensive OPLL carry a high risk of dural tears, construct failure, and pseudoarthrosis.

Question 56

A 45-year-old construction worker falls from scaffolding, sustaining an L1 burst fracture. He is neurologically intact. CT imaging shows 15 degrees of local kyphosis, 30% canal compromise, and an intact posterior tension band. According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is the recommended management?

Explanation

This patient has a TLICS score of 2 (Morphology: Burst = 1; Neuro: Intact = 0; PLC: Intact = 0). A score of 3 or less is an indication for nonoperative management, typically with a TLSO.

Question 57

A 28-year-old elite volleyball attacker presents with vague posterior shoulder pain and isolated weakness in external rotation. Physical examination reveals prominent atrophy of the infraspinatus fossa, while the supraspinatus bulk is normal. Which of the following anatomic structures is the most likely site of pathology?

Explanation

Isolated atrophy and weakness of the infraspinatus indicates compression of the suprascapular nerve at the spinoglenoid notch. Compression at the more proximal suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 58

A 65-year-old male with a 20-year history of ankylosing spondylitis presents to the emergency department with severe, localized lower thoracic back pain after slipping on ice. He denies any neurologic deficits. Initial plain radiographs of the thoracic and lumbar spine show no obvious fracture. What is the most appropriate next step in management?

Explanation

Patients with ankylosing spondylitis have a rigid, osteopenic spine highly susceptible to unstable fractures from low-energy trauma. Plain radiographs often miss these fractures; therefore, a CT or MRI of the entire spine is mandatory.

Question 59

A 68-year-old female sustains a 3-part proximal humerus fracture. Current anatomical studies have revised historical teachings regarding the primary blood supply to the humeral head. Which vessel is now recognized as providing the predominant vascular contribution to the humeral head?

Explanation

Recent quantitative anatomical studies have demonstrated that the posterior circumflex humeral artery provides the primary blood supply (up to 64%) to the humeral head, superseding the traditional teaching of the anterior circumflex humeral artery.

Question 60

Based on the Spine Patient Outcomes Research Trial (SPORT) data for degenerative spondylolisthesis, which of the following statements best characterizes the long-term outcomes of surgical versus nonoperative treatment?

Explanation

The SPORT trial demonstrated that patients who undergo surgery for degenerative spondylolisthesis have significantly better outcomes in pain and physical function at 4 and 8 years compared to those treated nonoperatively.

Question 61

A 45-year-old male presents with acute anterior shoulder pain and weakness after attempting to break a fall with his arm extended and externally rotated. On examination, he exhibits a positive lift-off test and increased passive external rotation compared to the contralateral side. Which tendon is most likely ruptured?

Explanation

The subscapularis is the primary internal rotator of the shoulder. A positive lift-off test, belly-press test, and increased passive external rotation are classic physical exam findings for a subscapularis tear.

Question 62

A 14-year-old female with adolescent idiopathic scoliosis (AIS) is evaluated. She is pre-menarcheal and Risser 0. Standing radiographs reveal a right thoracic curve measuring 35 degrees. What is the most appropriate management plan?

Explanation

In a skeletally immature patient (Risser 0-2, pre-menarcheal) with an AIS curve between 25 and 45 degrees, bracing is indicated to halt progression. A dose-response relationship exists, with >18 hours of daily wear showing the greatest benefit.

Question 63

A 25-year-old professional baseball pitcher presents with vague, deep shoulder pain occurring primarily during the late cocking phase of throwing. MRI arthrogram reveals a SLAP tear. The pathophysiology of this specific injury pattern in throwers is most commonly attributed to which of the following mechanisms?

Explanation

In overhead throwing athletes, a SLAP tear is typically caused by the "peel-back" mechanism. During maximal abduction and external rotation (late cocking phase), a torsional force is transmitted to the superior labrum via the biceps anchor.

Question 64

An 82-year-old female presents after a mechanical fall with isolated neck pain. CT of the cervical spine reveals a Type II odontoid fracture with 6 mm of posterior displacement. Which of the following factors is the strongest predictor for nonunion if this fracture is treated nonoperatively in a hard cervical collar?

Explanation

Risk factors for nonunion of Type II odontoid fractures include age >50 years, initial displacement >5 mm, and fracture comminution. Advanced age is one of the most consistently cited independent predictors of nonunion.

Question 65

A 30-year-old male sustains a closed midshaft clavicle fracture. Which of the following radiographic findings is the strongest absolute or relative indication for operative fixation (ORIF) to prevent nonunion and symptomatic malunion?

Explanation

Shortening >2 cm and 100% displacement in adult midshaft clavicle fractures are associated with a significantly increased risk of nonunion and poor functional outcomes if treated nonoperatively.

Question 66

A 55-year-old male with a history of intravenous drug use presents with excruciating lower back pain, fever, and elevated CRP. MRI reveals L3-L4 discitis and osteomyelitis. The infection in pyogenic spondylodiscitis in adults most commonly begins in which anatomic structure before spreading to the intervertebral disc?

Explanation

In adults, pyogenic spondylodiscitis typically originates via hematogenous spread to the highly vascularized subchondral bone adjacent to the vertebral endplate. The avascular disc is subsequently infected via contiguous spread.

Question 67

A 50-year-old female with poorly controlled Type II diabetes mellitus presents with insidious onset of progressive shoulder stiffness and pain, consistent with adhesive capsulitis. Histologic analysis of the affected capsular tissue is most likely to demonstrate which of the following?

Explanation

Adhesive capsulitis is characterized histologically by dense fibroblastic proliferation and type III collagen deposition. This contracture primarily affects the rotator interval capsule and the coracohumeral ligament.

Question 68

A 62-year-old male with a history of prostate cancer complains of worsening, unrelenting nocturnal back pain. AP radiograph of the lumbar spine reveals the "winking owl" sign at L3. This radiographic finding represents destruction of which anatomic structure?

Explanation

The "winking owl" sign on an AP spine radiograph indicates the destruction of a pedicle, often due to a metastatic lesion. The missing pedicle creates the appearance of a winking eye.

Question 69

A 24-year-old male cyclist falls directly onto the point of his shoulder. Radiographs show a 100% superior displacement of the distal clavicle relative to the acromion, with a coracoclavicular distance increased by 50% compared to the contralateral side. The deltotrapezial fascia is intact on physical exam. What is the most appropriate initial management?

Explanation

This represents a Type III acromioclavicular (AC) joint separation. Nonoperative management with a sling and early ROM yields excellent functional outcomes and is the standard initial treatment for uncomplicated Type III injuries.

Question 70

In the biomechanical design of a reverse total shoulder arthroplasty (RTSA), moving the center of rotation medially and inferiorly achieves which of the following mechanical advantages?

Explanation

RTSA medialize and inferiorize the center of rotation. This dramatically increases the moment arm of the deltoid and tension on the muscle, allowing it to functionally elevate the arm in the absence of a competent rotator cuff.

Question 71

A 35-year-old female presents after a high-speed motor vehicle collision. Lateral cervical spine radiographs demonstrate approximately 25% anterior subluxation of the C4 vertebral body over C5. Which of the following injuries is most consistent with this radiographic finding?

Explanation

Unilateral facet dislocations typically present with 25% anterior subluxation of the vertebral body on lateral plain films. Bilateral facet dislocations usually demonstrate 50% or greater anterior subluxation.

Question 72

A 19-year-old male presents with acute dyspnea, dysphagia, and a choking sensation after a pile-up in a rugby game. Physical examination reveals an asymmetric depression at the medial aspect of the right clavicle. A CT scan confirms a posterior sternoclavicular joint dislocation. What is the most critical anatomical structure at risk immediately posterior to this injury?

Explanation

Posterior sternoclavicular dislocations are true orthopedic emergencies due to the risk of compression or laceration to the great vessels (innominate vein/artery, superior vena cava), trachea, and esophagus.

ABOS Part I Orthopaedic Deformity Correction, Limb Reconstruction & Gait Analysis Review | Part 21914

ABOS Part I & OITE Orthopedic Board Review: Spine & Shoulder MCQs & Clinical Cases | Part 21602

Key Takeaway

ABOS Part I & OITE Orthopedic Board Review: Spine & Shoulder MCQs & Clinical Cases | Part 21602

Chapter Index