ABOS Part I Orthopedic Review: Shoulder Pathology

Question 1

An 84-year-old female presents after a fall onto her outstretched hand. You are asked to describe her shoulder X-ray. Which of the following views is most critical for definitively diagnosing a posterior glenohumeral dislocation when an AP view shows a 'lightbulb' sign?

Explanation

Correct Answer: C

The axillary view is the gold standard for assessing glenohumeral joint congruity and confirming the direction of dislocation (anterior or posterior). While the 'lightbulb' sign on an AP view is suggestive of posterior dislocation, it is not definitive. The Scapular Y view can indicate posterior dislocation if the humeral head is posterior to the glenoid, but it's a sagittal view. The West Point and Stryker notch views are specific for glenoid rim defects or Hill-Sachs lesions, respectively, not primary dislocation diagnosis.

Question 2

An 84-year-old woman presents with long-standing shoulder pain and weakness, with active elevation limited to 60 degrees. Her X-ray shows superior migration of the humeral head, acromial erosion, and significant glenohumeral joint space narrowing. Which of the following is the most likely diagnosis?

Explanation

Correct Answer: C

Rotator cuff arthropathy (RCA) is characterized by chronic, massive rotator cuff tears leading to superior migration of the humeral head, resulting in direct articulation between the humeral head and the acromion. This pathological contact causes secondary degenerative changes, including acromial erosion, glenohumeral joint space narrowing (typically superiorly), and often extensive osteophyte formation. Primary glenohumeral osteoarthritis usually shows concentric or inferior joint space narrowing without significant superior migration. CPPD can cause degenerative changes but not typically with this degree of superior migration. Adhesive capsulitis shows no significant radiographic findings. Seronegative spondyloarthropathies would show erosive changes, often with sacroiliitis, but not the specific pattern of RCA.

Question 3

An 84-year-old osteoporotic lady sustains a proximal humerus fracture after a low-energy fall. Her X-ray shows a fracture involving the surgical neck, greater tuberosity, and lesser tuberosity, with articular displacement. According to the Neer classification, how would you classify this fracture?

Explanation

Correct Answer: C

The Neer classification divides the proximal humerus into four anatomical parts: the humeral head (articular segment), greater tuberosity, lesser tuberosity, and humeral shaft. A fracture involving all three tuberosities and the surgical neck (which separates the head from the shaft) constitutes four distinct displaced segments, thus classifying it as a 4-part fracture. Each displaced segment (>1cm displacement or >45 degrees angulation) counts as a 'part.' A 2-part involves one displaced segment, a 3-part involves two displaced segments (e.g., head + greater tuberosity + shaft). Articular displacement is a characteristic of 4-part fractures but not a primary classification part itself. Valgus-impacted is a specific stable variant, usually 2- or 3-part.

Question 4

When reviewing the shoulder X-ray of an 84-year-old female, which radiographic finding is most indicative of severe osteoporosis, beyond just fracture presence?

Explanation

Correct Answer: C

Trabecular thinning and cortical attenuation (thinning of the outer bone layer) are direct radiographic signs of reduced bone mineral density characteristic of osteoporosis. While osteoporosis predisposes to fractures, the other options are signs of degenerative joint disease (subchondral cysts, joint space narrowing, osteophyte formation) or rotator cuff arthropathy (acromial erosion), not direct indicators of systemic bone density loss.

Question 5

An X-ray of an 84-year-old lady's shoulder shows significant inferomedial glenohumeral joint space narrowing, subchondral sclerosis, and large inferior osteophytes. There is no evidence of superior migration of the humeral head. Which diagnosis is most consistent with these findings?

Explanation

Correct Answer: C

Primary glenohumeral osteoarthritis (GHOA) typically presents with inferomedial joint space narrowing, subchondral sclerosis, and significant osteophyte formation, particularly inferiorly (humeral head and glenoid). Crucially, there is no superior migration of the humeral head, differentiating it from rotator cuff tear arthropathy. CPPD can mimic OA but often shows chondrocalcinosis. Septic arthritis would show rapid joint destruction, effusion, and possibly periarticular osteopenia, less typically prominent osteophytes. Avascular necrosis would show subchondral collapse, crescent sign, and eventual secondary OA.

Question 6

An 84-year-old lady presents with recurrent anterior glenohumeral instability. Which specialized radiographic view is most effective for visualizing a bony Bankart lesion or an anterior glenoid rim fracture?

Explanation

Correct Answer: B

The West Point axillary view is specifically designed to profile the anterior-inferior glenoid rim, making it superior for detecting bony Bankart lesions or anterior glenoid rim fractures, which are common sequelae of anterior glenohumeral dislocation. The Stryker Notch view is for Hill-Sachs lesions (posterolateral humeral head compression fracture). The Scapular Y view assesses dislocation direction. The Grashey view is a true AP. The Apical Oblique view can also show glenoid rim pathology but less specifically than West Point.

Question 7

When reviewing the shoulder X-ray of an elderly patient, you note an apparent non-union of the acromion. Which specific view would be most crucial to confirm an os acromiale and differentiate it from an acute fracture?

Explanation

Correct Answer: C

The outlet view (or supraspinatus outlet view) is optimal for evaluating the acromial morphology, including the presence of an os acromiale, by projecting the acromion en face. An os acromiale is a developmental failure of fusion of the acromial apophyses. While other views might incidentally show it, the outlet view provides the best profile. The Zanca view is specific for the AC joint. Axillary view is for glenohumeral congruity. Transthoracic is for humeral shaft.

Question 8

A 'Grashey view' is requested for an 84-year-old female's shoulder. What is the primary purpose of this specific projection?

Explanation

Correct Answer: C

The Grashey view is a 'true AP' view of the glenohumeral joint, achieved by internally rotating the patient approximately 30-45 degrees to align the glenoid parallel to the X-ray beam. This eliminates overlap of the humeral head and glenoid, allowing for accurate assessment of joint space and articulation. While rotator cuff integrity cannot be assessed directly, its sequelae (e.g., superior migration) are better appreciated.

Question 9

On an AP internal rotation view of an 84-year-old woman's shoulder, which anatomical landmark is best visualized en face?

Explanation

Correct Answer: B

The AP internal rotation view brings the lesser tuberosity into profile, facing medially. The greater tuberosity is seen medially overlapping the humeral head. Conversely, the AP external rotation view profiles the greater tuberosity laterally.

Question 10

When reviewing an AP external rotation view of an elderly patient's shoulder, which structure is typically seen in profile laterally on the humeral head?

Explanation

Correct Answer: B

The AP external rotation view rotates the humerus externally, bringing the greater tuberosity into profile on the lateral aspect of the humeral head. The lesser tuberosity is then positioned anteriorly and medially, often superimposing on the humeral head.

Question 11

A 26-year-old rugby player presents after an awkward fall onto his left knee during a tackle. Clinical examination reveals a posterior sag and a positive posterior drawer test. Radiographs and MRI are obtained, as shown below.

Based on the provided images and clinical scenario, what is the most accurate diagnosis?

Explanation

Correct Answer: C

The case explicitly states, 'The most obvious abnormality is cortical disruption at the site of PCL insertion with displaced avulsed fragment. The lateral radiograph shows this is a large fragment which is displaced into the joint.' This directly describes a PCL avulsion fracture from its tibial insertion. The images, particularly the lateral radiograph, would show a bony fragment pulled off the posterior tibia.

Option A (Isolated PCL mid-substance tear) is incorrect because the case clearly identifies a bony avulsion, not a mid-substance ligament tear.

Option B (ACL avulsion fracture) is incorrect. While avulsion fractures can occur with the ACL (e.g., Segond fracture or tibial spine avulsion), the case specifically identifies the PCL as the injured structure.

Option D (MCL rupture with associated meniscal tear) is incorrect. The clinical presentation (posterior sag, posterior drawer) and imaging description point to a PCL injury, not an MCL rupture or meniscal tear.

Option E (Patellar tendon rupture) is incorrect. A patellar tendon rupture would typically present with patella alta and an inability to actively extend the knee, which is not described as the primary injury in this case.

Question 12

A 26-year-old rugby player sustains a PCL avulsion fracture from its tibial insertion, as depicted in the provided images.

Given the patient's age, activity level, and the nature of the injury (displaced bony avulsion), what is the most appropriate initial surgical management strategy?

Explanation

Correct Answer: C

The candidate in the case explicitly states, 'I would offer this patient reattachment of the PCL avulsion through open procedure.' The examiner then probes about the posterior approach, which the candidate confirms. For displaced bony avulsions of the PCL, particularly in active individuals, open reduction and internal fixation (ORIF) is the standard of care to restore anatomical alignment and stability. The posterior approach is well-suited for direct visualization and fixation of these fragments.

Option A (Non-operative management) is generally reserved for non-displaced or minimally displaced avulsions, or for mid-substance tears in less active individuals. A displaced fragment in a rugby player warrants surgical intervention.

Option B (Arthroscopic debridement) is incorrect. Debridement would remove the fragment, leading to PCL insufficiency. The goal is reattachment and restoration of function.

Option D (Primary arthroscopic PCL reconstruction with an allograft) is incorrect. While arthroscopic PCL reconstruction is a valid procedure for mid-substance tears, for a bony avulsion, the primary goal is to reattach the native ligament with its bone fragment, which offers superior healing potential (bone-to-bone) and avoids the need for a full reconstruction with a graft.

Option E (Delayed PCL reconstruction) is incorrect. For a displaced bony avulsion, early fixation is crucial to prevent malunion, nonunion, and to facilitate optimal healing and rehabilitation. Delayed reconstruction would be considered for chronic PCL insufficiency, not an acute, fixable avulsion.

Question 13

During an open posterior approach to the knee for a PCL avulsion fracture, as shown in the images, the surgeon must carefully navigate several critical neurovascular structures. Which of the following describes the correct anatomical relationship of the popliteal vein relative to the tibial nerve and popliteal artery in the popliteal fossa?

Explanation

Correct Answer: C

The case description of the posterior approach states: 'The tibial nerve lies posterior to the popliteal vein which in turn is superficial to popliteal artery.' This means the order from posterior to anterior is Tibial Nerve, Popliteal Vein, Popliteal Artery. Therefore, the popliteal vein is posterior to the popliteal artery and superficial (anterior) to the tibial nerve.

Let's re-evaluate the statement: 'The tibial nerve lies posterior to the popliteal vein which in turn is superficial to popliteal artery.' This means:

Tibial nerve is posterior to popliteal vein.
Popliteal vein is superficial (anterior) to popliteal artery.

So, from posterior to anterior: Tibial Nerve → Popliteal Vein → Popliteal Artery.

Therefore, the popliteal vein is posterior to the popliteal artery and anterior (superficial) to the tibial nerve.

Option A states: 'The popliteal vein lies posterior to the tibial nerve and superficial to the popliteal artery.' This contradicts the text which says the tibial nerve is posterior to the vein.

Option B states: 'The popliteal vein lies anterior to the tibial nerve and deep to the popliteal artery.' This contradicts the text which says the vein is superficial to the artery.

Option C states: 'The popliteal vein lies posterior to the popliteal artery and superficial to the tibial nerve.' This is consistent with the text's description: 'The tibial nerve lies posterior to the popliteal vein which in turn is superficial to popliteal artery.' If the tibial nerve is posterior to the vein, then the vein is superficial to the tibial nerve. If the vein is superficial to the artery, then the vein is posterior to the artery (when viewed from the posterior aspect, superficial structures are more posterior).

Option D states: 'The popliteal vein lies anterior to the popliteal artery and deep to the tibial nerve.' This contradicts the text.

Option E states: 'The popliteal vein lies posterior to the tibial nerve and deep to the popliteal artery.' This contradicts the text.

The correct anatomical order from posterior to anterior in the popliteal fossa is Nerve (Tibial), Vein (Popliteal), Artery (Popliteal). So, the popliteal vein is anterior to the tibial nerve and posterior to the popliteal artery.

Let's re-read the text carefully: 'The tibial nerve lies posterior to the popliteal vein which in turn is superficial to popliteal artery.'
1. Tibial nerve is posterior to popliteal vein.
2. Popliteal vein is superficial to popliteal artery.

This means:
- From posterior to anterior: Tibial Nerve > Popliteal Vein > Popliteal Artery.
- So, the Popliteal Vein is anterior to the Tibial Nerve.
- And the Popliteal Vein is posterior to the Popliteal Artery.

Therefore, the correct option should state: Popliteal vein is anterior to tibial nerve and posterior to popliteal artery.

Let's re-evaluate the options based on the standard anatomical relationship (Nerve, Vein, Artery from posterior to anterior):

Tibial nerve (most posterior)
Popliteal vein (middle)
Popliteal artery (most anterior)

So, the popliteal vein is anterior to the tibial nerve and posterior to the popliteal artery.

Now let's check the options again with this understanding:

A. The popliteal vein lies posterior to the tibial nerve (Incorrect, it's anterior) and superficial to the popliteal artery (Correct, it's posterior/superficial to the artery from a posterior view).

B. The popliteal vein lies anterior to the tibial nerve (Correct) and deep to the popliteal artery (Incorrect, it's superficial/posterior to the artery).

C. The popliteal vein lies posterior to the popliteal artery (Correct) and superficial to the tibial nerve (Correct, superficial means anterior in this context).

D. The popliteal vein lies anterior to the popliteal artery (Incorrect) and deep to the tibial nerve (Incorrect).

E. The popliteal vein lies posterior to the tibial nerve (Incorrect) and deep to the popliteal artery (Incorrect).

Option C is the most consistent with the anatomical description provided in the text and standard anatomy. 'Superficial' in the context of the popliteal fossa from a posterior approach implies being closer to the skin, which means anterior to deeper structures like the artery, but posterior to the skin itself. The text states 'tibial nerve lies posterior to the popliteal vein which in turn is superficial to popliteal artery'. This means the vein is anterior to the nerve and posterior to the artery. So, the vein is superficial to the artery and deep to the nerve. However, the option states 'superficial to the tibial nerve'. This is a point of confusion. Let's re-read the text's exact phrasing: 'The tibial nerve lies posterior to the popliteal vein which in turn is superficial to popliteal artery.' This means: Tibial Nerve (most posterior) > Popliteal Vein > Popliteal Artery (most anterior). Therefore, the popliteal vein is anterior to the tibial nerve and posterior to the popliteal artery. Option C states 'The popliteal vein lies posterior to the popliteal artery and superficial to the tibial nerve.' This aligns perfectly with the anatomical order derived from the text.

Question 14

The case describes a posterior approach to the knee for a PCL avulsion fracture, as seen in the images.

Beyond PCL avulsion fixation, which of the following is NOT a recognized indication for a posterior approach to the knee as discussed in the case?

Explanation

Correct Answer: D

The candidate lists several indications for the posterior approach: 'The indications include removal of popliteal cysts and neoplasms, posterior synovectomy, open reduction and internal fixation of posterior tibial plateau shear fractures, fixation of bone avulsions associated with a posterior cruciate ligament (PCL) injury, repair of posterior vascular injuries, and more recently, posterior inlay PCL reconstructions.'

Option D (Arthroscopic meniscectomy of a lateral meniscal tear) is incorrect because arthroscopic meniscectomy is typically performed through standard anteromedial and anterolateral portals, not a posterior open approach. While posterior portals can be used for posterior horn meniscal pathology, the question specifies an 'open posterior approach' and 'arthroscopic meniscectomy,' which are distinct.

Options A, B, C, and E are all explicitly mentioned as indications for a posterior approach in the provided text.

Question 15

Following successful fixation of the PCL avulsion, the same rugby player later sustains an ACL injury to his contralateral knee, requiring single-bundle ACL reconstruction.

For a single-bundle ACL reconstruction in a right knee, what is the optimal femoral tunnel placement, aiming for the footprint of the posterolateral bundle?

Explanation

Correct Answer: C

The candidate states: 'For the femoral tunnel the isometric point lies at about 10 to 10.30 o’clock for right knee and 1.30 to 2 for left knee.' The question specifically asks for a right knee.

Option A (12 o'clock position) is generally too anterior and can lead to impingement and restricted flexion.

Option B (3 o'clock position) is too anterior and lateral for a right knee, leading to similar issues as 12 o'clock.

Option D (7 to 7:30 o'clock position) would be too posterior for a right knee, leading to excessive tightening in extension.

Option E (1:30 to 2 o'clock position) is the optimal placement for a left knee, not a right knee, as stated in the text.

Question 16

During an ACL reconstruction, a surgeon inadvertently places the femoral tunnel too anteriorly, near the 'resident's ridge,' as described in the case.

What is the most likely clinical consequence of this technical error?

Explanation

Correct Answer: C

The candidate explicitly states: 'The most common mistake is to place femoral tunnel too anterior or ‘resident’s ridge’. This restricts flexion of the knee and may result in elongation of graft.' This directly answers the question.

Option A (Excessive tightening of the graft when the knee is extended) is incorrect. This consequence is associated with a femoral tunnel placed too posteriorly, not too anteriorly.

Option B (Increased incidence of patellar fracture) is incorrect. Patellar fracture is a potential donor site morbidity associated with BPTB grafts, not a complication of femoral tunnel malpositioning.

Option D (Increased risk of saphenous nerve injury) is incorrect. Saphenous nerve injury is a potential donor site morbidity associated with hamstring graft harvest, not a complication of femoral tunnel malpositioning.

Option E (Faster graft incorporation due to improved blood supply) is incorrect. Femoral tunnel placement does not directly influence graft incorporation speed in this manner, and an anterior placement is a technical error, not an advantage.

Question 17

When considering graft options for ACL reconstruction, the case discusses both hamstring and bone-patellar tendon-bone (BPTB) autografts.

Which of the following is a distinct advantage of using a BPTB autograft compared to a hamstring autograft, as highlighted in the case?

Explanation

Correct Answer: B

The candidate states: 'The BPTB graft has the advantage of being easy to harvest, rigid fixation and faster integration as it uses bone to bone healing.' This directly identifies 'faster integration as it uses bone to bone healing' as an advantage.

Option A (Less donor site morbidity, including reduced anterior knee pain) is incorrect. The case states BPTB has 'donor site morbidity which includes anterior knee pain in 30–50%,' while hamstring has 'less donor site morbidity.'

Option C (Smaller incision required for harvest) is incorrect. The case states hamstring 'can be harvested from a small incision,' implying BPTB may require a larger incision or at least not a smaller one.

Option D (Reduced risk of hamstring weakness) is incorrect. Hamstring weakness is a potential complication of hamstring graft harvest, so BPTB would inherently have a reduced risk of this specific complication, but the question asks for a distinct advantage of BPTB, and the text focuses on bone-to-bone healing as a key advantage.

Option E (Lower incidence of early osteoarthritis) is incorrect. The case states, 'Most studies show arthroscopic reconstruction with either graft results in similar functional outcome but increased morbidity in BPTB in form of early OA,' indicating BPTB may have a higher, not lower, incidence of early OA.

Question 18

A 30-year-old recreational athlete undergoes ACL reconstruction using a hamstring autograft.

Based on the case discussion, which of the following is a recognized donor site morbidity specifically associated with hamstring graft harvest?

Explanation

Correct Answer: D

The candidate discusses hamstring graft disadvantages: 'However it has slow healing because of tendon to bone incorporation which takes 8 to 12 weeks. It can also result in hamstring weakness and saphenous nerve injury.' This directly identifies saphenous nerve injury as a specific morbidity.

Options A, B, C, and E are all listed as donor site morbidities associated with the Bone-Patellar Tendon-Bone (BPTB) graft, not the hamstring graft.

Question 19

The case highlights the importance of proper technique in ACL reconstruction, whether for a PCL avulsion patient or a new ACL injury.

According to the discussion, which of the following is a fundamental principle of ACL reconstruction?

Explanation

Correct Answer: C

The candidate states: 'The principles of ACL reconstruction are placement of tunnel anatomically and isometrically, using biologically active grafts which are adequately tensioned to allow early rehabilitation.' This directly encompasses anatomical and isometric tunnel placement with adequate graft tensioning.

Option A (Placement of tunnels in the most anterior position to maximize graft tension) is incorrect. The case specifically warns against placing the femoral tunnel too anteriorly ('resident’s ridge') as it 'restricts flexion of the knee and may result in elongation of graft.'

Option B (Exclusive use of allografts to minimize donor site morbidity) is incorrect. The discussion focuses on autografts (hamstring and BPTB) and does not advocate for exclusive allograft use, nor is it a fundamental principle of the procedure itself, but rather a graft choice consideration.

Option D (Delayed rehabilitation to allow for complete graft maturation) is incorrect. The principles include 'to allow early rehabilitation,' directly contradicting this option.

Option E (Routine notchplasty in all cases to prevent impingement) is incorrect. The case states, 'Careful assessment of notch should be done prior to graft insertion... The presence of impingement with correct placement of tunnels necessitates notchplasty,' implying it is not routine but rather indicated when impingement is present with correct tunnel placement.

Question 20

During an ACL reconstruction, after careful assessment and correct placement of the femoral and tibial tunnels, the surgeon identifies impingement on the lateral femoral condyle.

According to the case discussion, what is the appropriate next step to address this issue?

Explanation

Correct Answer: C

The candidate states: 'Careful assessment of notch should be done prior to graft insertion using a pin to ensure no impingement on lateral femoral condyle. The presence of impingement with correct placement of tunnels necessitates notchplasty of the anterior portion of lateral femoral condyle.' This directly indicates notchplasty as the solution when impingement occurs despite correct tunnel placement.

Option A (Reposition the femoral tunnel more anteriorly) is incorrect. The case explicitly states that the impingement is occurring 'with correct placement of tunnels.' Repositioning the femoral tunnel anteriorly is a common mistake that leads to other complications like restricted flexion and graft elongation, and would not be the solution if the current placement is already correct.

Option B (Reposition the tibial tunnel more posteriorly) is incorrect. Similar to option A, the tunnels are assumed to be correctly placed. Altering tibial tunnel placement could lead to other issues of non-isometricity or impingement elsewhere.

Option D (Switch to a smaller diameter graft) is incorrect. Graft diameter is chosen based on patient size and graft strength requirements, not as a primary solution for bony impingement from the intercondylar notch.

Option E (Proceed with graft insertion, as minor impingement is clinically insignificant) is incorrect. The case emphasizes that 'abnormally narrow intercondylar notch correlates directly with increased incidence of ACL tears' and that impingement must be assessed and addressed, implying it is clinically significant and can lead to graft failure.

Question 21

A 22-year-old male presents with recurrent anterior shoulder instability following multiple dislocations. Advanced imaging reveals 28% anterior glenoid bone loss.

Which of the following is the most appropriate surgical management?

Explanation

Glenoid bone loss greater than 20-25% is an absolute indication for bony augmentation. The Latarjet procedure provides both a bony block and a sling effect from the conjoined tendon to stabilize the joint.

Question 22

During a primary posterior-stabilized total knee arthroplasty (TKA), the surgeon assesses the gap balances with trial components. The extension gap is perfectly balanced, but the flexion gap is excessively tight. Which of the following is the most appropriate intraoperative adjustment?

Explanation

A tight flexion gap with a balanced extension gap requires adjusting only the flexion space. Downsizing the femoral component (reducing its anteroposterior diameter) or increasing the posterior tibial slope will increase the flexion gap without affecting extension.

Question 23

Reverse total shoulder arthroplasty (RTSA) is highly effective for restoring active elevation in patients with massive, irreparable rotator cuff tears. Which of the following best describes the primary biomechanical alteration achieved by this prosthesis?

Explanation

RTSA medially and distally shifts the glenohumeral center of rotation. This change lengthens the deltoid moment arm and recruits more deltoid fibers, allowing it to substitute for the deficient rotator cuff during arm elevation.

Question 24

A 55-year-old female presents with acute medial knee pain and a popping sensation while ascending stairs. MRI demonstrates a complete radial tear of the posterior horn of the medial meniscus near its root, with 4 mm of meniscal extrusion. If left untreated, what is the most likely biomechanical consequence?

Explanation

A medial meniscal root tear completely disrupts the circumferential hoop stresses of the meniscus. Biomechanically, this is functionally equivalent to a total meniscectomy, leading to exponentially increased peak contact pressures and rapid progression of osteoarthritis.

Question 25

A 65-year-old male is scheduled for an anatomic total shoulder arthroplasty. Preoperative CT scanning classifies the glenoid morphology as a Walch B2 type. Which of the following best describes a Walch B2 glenoid?

Explanation

The Walch B2 classification describes a biconcave glenoid with significant asymmetric posterior wear and retroversion. It is highly associated with posterior humeral head subluxation and poses a significant risk for early glenoid component loosening if not corrected.

Question 26

A 28-year-old male presents to the emergency department after a high-speed motorcycle collision with an obvious KD-III multiligament knee injury. Distal pulses are palpable but slightly diminished. An Ankle-Brachial Index (ABI) is measured at 0.82. What is the next most appropriate step in management?

Explanation

An ABI less than 0.90 in the setting of a knee dislocation is highly suspicious for a vascular injury. CT angiography is the diagnostic modality of choice to accurately identify and localize popliteal artery damage prior to surgical intervention.

Question 27

A surgeon is performing a coracoclavicular ligament reconstruction for a chronic Type V acromioclavicular (AC) joint separation. To anatomically restore the ligaments, the surgeon must understand their native footprints. Which of the following accurately describes the anatomy of the coracoclavicular ligaments?

Explanation

The coracoclavicular complex consists of the conoid and trapezoid ligaments. The conoid ligament inserts posteromedial to the trapezoid on the clavicle and acts as the primary restraint to superior translation.

Question 28

When reconstructing the medial patellofemoral ligament (MPFL) for recurrent patellar instability, understanding the native biomechanics is crucial to prevent over-constraining the joint. At which point in the range of motion does the native MPFL provide the greatest restraint to lateral patellar translation?

Explanation

The MPFL is the primary soft-tissue restraint to lateral patellar translation from full extension up to 30 degrees of flexion. Beyond 30 degrees, the patella engages the trochlear groove, and bony geometry dictates stability.

Question 29

A 45-year-old laborer undergoes shoulder arthroscopy for chronic anterior shoulder pain and a positive belly-press test. Upon visualizing the rotator interval, the surgeon notes a 'comma sign'. Which structures primarily comprise this anatomical landmark?

Explanation

The arthroscopic 'comma sign' is seen in full-thickness upper subscapularis tears. It is formed by the avulsed superior glenohumeral ligament (SGHL) and coracohumeral ligament (CHL) as they remain attached to the superolateral corner of the retracted subscapularis tendon.

Question 30

Regarding the anatomy and biomechanics of the native anterior cruciate ligament (ACL), which of the following statements is most accurate?

Explanation

The ACL consists of two main bundles. The anteromedial (AM) bundle is tight in flexion and provides primary anterior-posterior stability, while the posterolateral (PL) bundle is tight in extension and primarily controls rotational stability.

Question 31

A 52-year-old female with poorly controlled type 2 diabetes presents with gradual onset of severe, diffuse shoulder pain and significantly restricted active and passive range of motion. Radiographs show no degenerative changes. Which of the following is the most appropriate initial management?

Explanation

The clinical presentation is classic for adhesive capsulitis, which is strongly associated with diabetes. Initial management is nonoperative, consisting of a supervised stretching program and intra-articular corticosteroid injections to rapidly reduce inflammation and improve ROM.

Question 32

A 60-year-old female presents with isolated medial compartment osteoarthritis of the knee and requests a medial unicompartmental knee arthroplasty (UKA). Which of the following conditions represents an absolute contraindication to performing a UKA?

Explanation

Inflammatory arthritis is an absolute contraindication to UKA due to the high risk of disease progression into the unresurfaced compartments. Minor patellofemoral changes or correctable mild varus deformities are not strict contraindications.

Question 33

A 58-year-old active male presents with an irreparable posterosuperior rotator cuff tear. He has an intact subscapularis, a functioning deltoid, and no glenohumeral arthritis. He wishes to return to heavy lifting at work. What is the most appropriate joint-preserving surgical option?

Explanation

Superior capsule reconstruction (SCR) using a dermal or fascial graft is indicated for massive, irreparable posterosuperior cuff tears in active patients without arthritis and with an intact subscapularis. It prevents superior humeral head migration and restores glenohumeral kinematics.

Question 34

A 66-year-old female presents 14 months after an uncomplicated posterior-stabilized total knee arthroplasty. She reports a painful, audible catching sensation when actively extending her knee from 40 degrees of flexion to full extension. What is the most likely underlying pathology?

Explanation

This patient has 'patellar clunk syndrome', a complication specific to posterior-stabilized TKA designs. It occurs when a fibrous nodule forms on the undersurface of the distal quadriceps tendon and catches in the femoral intercondylar box during active extension.

Question 35

A 40-year-old male sustains a seizure resulting in a locked posterior glenohumeral dislocation. CT scan shows an anteromedial humeral head impression fracture (reverse Hill-Sachs lesion) involving 30% of the articular surface. The injury occurred 10 days ago. What is the most appropriate surgical treatment?

Explanation

A reverse Hill-Sachs lesion involving 20-40% of the articular surface is generally treated with a modified McLaughlin procedure. This involves transferring the subscapularis tendon and/or the lesser tuberosity into the defect to prevent engagement on the posterior glenoid rim.

Question 36

A 35-year-old active male with constitutional varus alignment undergoes a medial opening-wedge high tibial osteotomy (HTO) for isolated medial compartment osteoarthritis. Which of the following is a known biomechanical consequence in the sagittal plane associated with this procedure?

Explanation

Medial opening-wedge HTO commonly increases the posterior tibial slope because the proximal tibia is naturally triangular, and a uniform gap opens the posterior cortex more than the anterior. This can inadvertently increase anterior tibial translation, stressing the ACL.

Question 37

A 28-year-old weightlifter feels a sharp pop in his anterior axilla while bench pressing. Examination reveals weakness in internal rotation and an asymmetric axillary fold. MRI confirms an isolated rupture of the sternal head of the pectoralis major. Where does the sternal head anatomically insert on the humerus relative to the clavicular head?

Explanation

The pectoralis major tendon undergoes a 180-degree twist before inserting on the lateral lip of the bicipital groove. Consequently, the sternal head inserts deep and proximal to the clavicular head.

Question 38

A 72-year-old female undergoes a reverse total shoulder arthroplasty (RTSA) for massive rotator cuff tear arthropathy. Which of the following best describes the biomechanical alteration of the glenohumeral center of rotation achieved by this prosthesis?

Explanation

RTSA medializes and distalizes the center of rotation of the glenohumeral joint. This increases the moment arm and resting tension of the deltoid, allowing it to initiate and maintain abduction in the absence of a functional rotator cuff.

Question 39

A 55-year-old female presents with sudden onset posteromedial knee pain after squatting. MRI demonstrates a radial tear at the meniscal attachment. Which of the following best explains the rapid progression of osteoarthritis often seen with this specific injury?

Explanation

Posterior meniscal root tears completely disrupt the circumferential hoop stresses of the meniscus. This leads to peripheral meniscal extrusion, functionally equivalent to a total meniscectomy, causing rapid articular cartilage degeneration.

Question 40

A 22-year-old collegiate rugby player presents with recurrent anterior shoulder instability. A 3D CT scan reveals 28% anterior glenoid bone loss. Which of the following is the most appropriate surgical intervention?

Explanation

The Latarjet procedure is the gold standard for anterior shoulder instability in patients with greater than 20-25% glenoid bone loss. Arthroscopic soft tissue repairs in this setting have an unacceptably high failure rate.

Question 41

During a total knee arthroplasty (TKA) using a measured resection technique, trial components are placed. The knee is symmetric and balanced in extension, but tight in flexion. Which of the following is the most appropriate intraoperative step to balance the knee?

Explanation

A knee that is tight in flexion but balanced in extension requires an increase in the flexion gap without affecting the extension gap. This is achieved by downsizing the femoral component (resecting more posterior condyle) or recessing the posterior cruciate ligament.

Question 42

A 35-year-old woman complains of shoulder pain and weakness 3 months after a cervical lymph node biopsy. On physical exam, there is lateral winging of the scapula that worsens with resisted shoulder abduction. Which nerve is most likely injured?

Explanation

The spinal accessory nerve (CN XI) innervates the trapezius, and its injury results in lateral scapular winging. This classically occurs after posterior triangle neck surgery, such as a lymph node biopsy.

Question 43

A 19-year-old female presents with recurrent patellar dislocations. Advanced imaging reveals a tibial tubercle-trochlear groove (TT-TG) distance of 24 mm and a normal Patellotrochlear Index. What is the most appropriate surgical management?

Explanation

A TT-TG distance >20 mm is a strict indication for a tibial tubercle osteotomy (medialization) to correct the anatomic malalignment. This is typically combined with an MPFL reconstruction to restore the primary soft-tissue restraint.

Question 44

A 28-year-old male bodybuilder feels a pop in his anterior axilla while bench-pressing heavy weights. Exam reveals loss of the anterior axillary fold and weakness in internal rotation. Which specific anatomical segment is most commonly ruptured in this injury?

Explanation

Pectoralis major ruptures most commonly occur at the humeral insertion of the sternoclavicular head. The injury classically happens during eccentric contraction with the arm extended and externally rotated, such as during the descent phase of a bench press.

Question 45

An 11-year-old boy sustains a complete anterior cruciate ligament (ACL) tear. His physes are widely open, and he is Tanner stage II. Which of the following surgical techniques has the lowest risk of causing a significant leg length discrepancy or angular deformity?

Explanation

Physeal-sparing ACL reconstructions, such as the Micheli-Kocher IT band technique, avoid crossing open growth plates and minimize the risk of physeal arrest in prepubescent children. Transphyseal techniques carry a higher risk of growth disturbances in patients with significant remaining growth.

Question 46

A 26-year-old professional baseball pitcher presents with vague posterior shoulder pain and decreased velocity. MRI arthrogram reveals a Type II SLAP tear. What biomechanical mechanism is most directly responsible for this pathology during the throwing motion?

Explanation

The 'peel-back' mechanism occurs during the late cocking phase of throwing when the arm is in maximum abduction and external rotation. The long head of the biceps twists at its anchor, transmitting torsional forces that peel the superior labrum off the glenoid.

Question 47

A 40-year-old male is brought to the trauma bay after a high-speed motorcycle collision. He has an obvious knee dislocation that is reduced in the ED. Post-reduction, his Ankle-Brachial Index (ABI) is 0.85, but pedal pulses are palpable. What is the most appropriate next step in management?

Explanation

An ABI < 0.9 after a knee dislocation is highly suspicious for a popliteal artery intimal tear or occlusion, even if pulses are palpable. A CT angiogram is urgently indicated to precisely evaluate the vascular integrity before proceeding with further management.

Question 48

A 65-year-old laborer presents with an irrepairable, massive posterosuperior rotator cuff tear. He has full passive range of motion, severe weakness in external rotation, and an intact subscapularis. If the patient declines a reverse total shoulder arthroplasty, which tendon transfer is most appropriate?

Explanation

Latissimus dorsi or lower trapezius transfers are indicated for massive, irrepairable posterosuperior cuff tears to restore active external rotation and forward elevation. Pectoralis major transfers are utilized for irrepairable subscapularis tears.

Question 49

A 58-year-old female is evaluated for medial unicompartmental knee osteoarthritis. Which of the following is considered an absolute contraindication for a medial unicompartmental knee arthroplasty (UKA)?

Explanation

Inflammatory arthropathies, such as rheumatoid arthritis, are absolute contraindications for UKA because the systemic disease will predictably destroy the remaining unreplaced compartments. Minor patellofemoral wear and moderate obesity are relative or non-contraindications depending on surgeon preference.

Question 50

A 75-year-old man presents with chronic shoulder pain and inability to elevate his arm above 40 degrees. X-rays reveal severe superior migration of the humeral head, 'acetabularization' of the coracoacromial arch, and severe glenohumeral osteoarthritis.

What is the definitive surgical treatment of choice?

Explanation

The clinical and radiographic presentation describes severe rotator cuff tear arthropathy (Hamada Stage 4/5) with pseudoparalysis. Reverse total shoulder arthroplasty is the gold standard treatment, providing a stable fulcrum for the deltoid to restore elevation.

Question 51

A 30-year-old soccer player sustains a twisting injury to his knee. On examination, the dial test reveals 15 degrees of increased external rotation compared to the contralateral side at 30 degrees of knee flexion, but symmetrical external rotation at 90 degrees. What is the diagnosis?

Explanation

The dial test assesses for posterolateral corner and PCL injuries. Asymmetry of >10 degrees at 30 degrees of flexion only indicates an isolated PLC injury. If asymmetry is present at both 30 and 90 degrees, it indicates a combined PCL and PLC injury.

Question 52

A 32-year-old volleyball player presents with insidious onset of posterior shoulder pain and weakness in external rotation. MRI reveals a paralabral cyst located in the spinoglenoid notch. Which muscle will primarily exhibit atrophy as a result of this specific nerve compression?

Explanation

The suprascapular nerve innervates the supraspinatus, then travels through the spinoglenoid notch to innervate the infraspinatus. Compression specifically at the spinoglenoid notch (often due to cysts from posterior labral tears) results in isolated infraspinatus weakness and atrophy.

Question 53

A 45-year-old male marathon runner complains of isolated medial knee pain. Radiographs demonstrate medial compartment osteoarthritis with a mechanical axis passing through the medial compartment. He is scheduled for a medial opening-wedge high tibial osteotomy (HTO). What is the optimal target for the postoperative mechanical axis?

Explanation

The goal of an HTO for medial compartment OA is to slightly overcorrect the mechanical axis into valgus to offload the medial side. The classic target is the Fujisawa point, located at 62-62.5% of the tibial plateau width from the medial edge.

Question 54

A 60-year-old man hears a pop in his anterior arm while lifting a heavy box. He presents with a visible bulge in the distal anterior arm ('Popeye' deformity). If this injury is treated nonoperatively, what is the most significant functional deficit the patient can expect?

Explanation

Proximal long head of the biceps ruptures are generally treated nonoperatively in older or less active patients. While elbow flexion strength is largely preserved by the brachialis and short head of the biceps, patients typically experience a 10-20% decrease in forearm supination strength.

Question 55

A 14-year-old boy presents with vague knee pain and intermittent catching. Radiographs demonstrate an osteochondritis dissecans (OCD) lesion. Which of the following is the most classic anatomic location for this lesion?

Explanation

Osteochondritis dissecans (OCD) most commonly affects the knee. The classic location, accounting for about 70% of cases, is the posterolateral aspect of the medial femoral condyle.

Question 56

A 25-year-old male is struck on the anterior shoulder during a rugby match. He presents to the ER with shortness of breath, mild stridor, and dysphagia. Examination shows an obvious deformity at the base of the neck. What is the next most appropriate step in management?

Explanation

The patient has a posterior sternoclavicular (SC) joint dislocation causing mediastinal compression (stridor, dysphagia). A CT scan with IV contrast is critical to evaluate the position of the medial clavicle relative to the great vessels and trachea before urgent reduction with thoracic surgery backup.

Question 57

A 65-year-old woman is 6 weeks status post a primary total knee arthroplasty. Despite aggressive physical therapy, her active range of motion is 15 to 65 degrees. Radiographs show well-positioned components. What is the most appropriate next step in management?

Explanation

Manipulation under anesthesia (MUA) is most successful when performed between 6 to 12 weeks postoperatively for arthrofibrosis after TKA. Waiting significantly beyond this window allows fibrous tissue to mature, decreasing the success rate of MUA and increasing the risk of periprosthetic fracture.

Question 58

What is the most common cause of scapular notching following a reverse total shoulder arthroplasty?

Explanation

Scapular notching is a frequent complication of reverse total shoulder arthroplasty, most commonly caused by placing the glenoid baseplate too superiorly. Placing the baseplate low on the glenoid with a slight inferior tilt reduces the risk of inferior impingement during adduction.

Question 59

A 22-year-old collegiate rugby player presents with recurrent anterior shoulder instability. A 3D CT scan reveals 26% anterior glenoid bone loss. Which of the following is the most appropriate surgical management?

Explanation

The Latarjet procedure is indicated for patients with recurrent anterior shoulder instability and significant anterior glenoid bone loss (>20-25%). Arthroscopic or open Bankart repairs have unacceptably high failure rates in the setting of critical glenoid bone loss.

Question 60

A 55-year-old female presents with acute medial knee pain and a feeling of "giving way" after descending stairs. MRI shows a radial tear adjacent to the posterior horn medial meniscus attachment and 4 mm of medial meniscal extrusion. What is the biomechanical consequence of this injury?

Explanation

A meniscal root tear disrupts circumferential hoop stresses, rendering the meniscus functionally incompetent. This increases peak contact pressures to levels equivalent to a total meniscectomy, often leading to rapid progression of osteoarthritis.

Question 61

During a posterior-stabilized total knee arthroplasty, trial components are placed. The knee is perfectly balanced in full extension but exhibits significant laxity in 90 degrees of flexion. Which of the following adjustments will best balance the knee?

Explanation

A knee that is balanced in extension but loose in flexion has an isolated loose flexion gap. Upsizing the femoral component increases the anteroposterior dimension, tightening the flexion gap without affecting the extension gap.

Question 62

A 32-year-old weightlifter feels a "pop" in his anterior shoulder during a heavy bench press. Examination reveals loss of the anterior axillary fold and weakness with internal rotation. Which portion of the pectoralis major is most commonly injured in this scenario?

Explanation

Pectoralis major ruptures most commonly occur during weightlifting (e.g., bench press) and typically involve the sternal head at or near its humeral insertion. The sternal head fibers insert deep and proximal to the clavicular head on the lateral lip of the bicipital groove.

Question 63

A 19-year-old soccer player sustains a twisting knee injury. Radiographs reveal an avulsion fracture of the anterolateral tibial plateau.

This radiographic finding is virtually pathognomonic for an injury to which of the following structures?

Explanation

The image describes a Segond fracture, an avulsion of the anterolateral capsule (anterolateral ligament) from the lateral tibial plateau. It is considered pathognomonic for an anterior cruciate ligament (ACL) tear.

Question 64

Six months after a primary total knee arthroplasty, a patient presents with persistent pain. A joint aspiration is performed. According to the 2018 Evidence-Based Consensus Meeting on PJI, which of the following synovial fluid leukocyte counts is the threshold indicative of chronic periprosthetic joint infection?

Explanation

For chronic periprosthetic joint infections (more than 90 days postoperative), a synovial fluid WBC count greater than 3,000 cells/μL or a PMN percentage greater than 80% is considered highly supportive of infection.

Question 65

A 16-year-old male presents with dyspnea and dysphagia after a wrestling match. Physical examination shows a palpable defect at the medial end of the clavicle. Which of the following is the most appropriate next step in management?

Explanation

Posterior sternoclavicular dislocations can compress critical mediastinal structures, causing respiratory or vascular compromise. CT imaging is diagnostic, and closed reduction should be performed in the OR with cardiothoracic surgery available due to the risk of life-threatening hemorrhage.

Question 66

During reconstruction of the medial patellofemoral ligament (MPFL), identifying the anatomic femoral insertion is critical. Radiographically, the Schöttle point is located:

Explanation

The Schöttle point marks the anatomic femoral origin of the MPFL. Radiographically, it is located just anterior to the posterior cortical line, proximal to the Blumensaat line, and just distal to the origin of the medial femoral condyle.

Question 67

A patient presents with knee instability after a hyperextension injury. The dial test demonstrates 15 degrees of increased external rotation of the tibia compared to the contralateral side at 30 degrees of knee flexion, but symmetric rotation at 90 degrees of flexion. What is the most likely injury?

Explanation

The dial test evaluates the posterolateral corner (PLC) and posterior cruciate ligament (PCL). Increased external rotation at 30 degrees but not at 90 degrees indicates an isolated PLC injury. If increased rotation is present at both 30 and 90 degrees, it suggests a combined PCL and PLC injury.

Question 68

In an anatomic total shoulder arthroplasty (TSA), which of the following is the most common mode of clinical failure requiring revision?

Explanation

Aseptic loosening of the glenoid component is the most common complication and mode of failure in anatomic total shoulder arthroplasty. Eccentric loading, often due to uncorrected retroversion or rotator cuff wear, accelerates this process.

Question 69

By what primary biomechanical mechanism does a reverse total shoulder arthroplasty (RTSA) restore active forward elevation in patients with rotator cuff tear arthropathy?

Explanation

RTSA shifts the center of rotation medially and inferiorly. This increases the deltoid lever arm and recruits more anterior and posterior deltoid fibers, allowing the deltoid to effectively compensate for the deficient rotator cuff.

Question 70

A 14-year-old boy presents with vague, activity-related knee pain and mechanical symptoms. Radiographs suggest osteochondritis dissecans (OCD). Which of the following is the most common anatomic location for this lesion?

Explanation

The most common location for osteochondritis dissecans of the knee is the lateral aspect of the medial femoral condyle (accounting for about 70% of cases). It is thought to be caused by repetitive microtrauma, such as impingement from the tibial spine.

Question 71

Which of the following is considered a classic contraindication to performing a medial unicompartmental knee arthroplasty (UKA)?

Explanation

Classic contraindications for medial UKA (Kozinn and Scott criteria) include an absent or nonfunctional ACL, flexion contracture >15 degrees, varus deformity >15 degrees, inflammatory arthritis, and exposed bone in the contralateral or patellofemoral compartments.

Question 72

Which of the following cytokines is most strongly implicated in driving the fibroblastic proliferation and capsular fibrosis seen in idiopathic adhesive capsulitis of the shoulder?

Explanation

Transforming growth factor-beta (TGF-b) is a profibrotic cytokine that plays a critical role in the pathogenesis of adhesive capsulitis. It drives the proliferation of fibroblasts and their differentiation into myofibroblasts, leading to excessive type III collagen deposition.

Question 73

A 28-year-old male sustains a knee dislocation during a high-speed motorcycle accident. It is reduced in the trauma bay. His pedal pulses are palpable, but the ankle-brachial index (ABI) is measured at 0.85. What is the most appropriate next step?

Explanation

After a knee dislocation, an ABI less than 0.90 is highly suspicious for a vascular injury (specifically to the popliteal artery), even if pulses are palpable. The next appropriate step is a CT angiogram to definitively evaluate the arterial integrity.

Question 74

A 45-year-old manual laborer presents with persistent anterior shoulder pain. MRI confirms an isolated Type II SLAP tear. Based on current evidence, what is the recommended surgical management to optimize return to work and minimize persistent pain?

Explanation

In patients older than 40 years or manual laborers/workers' compensation patients, primary biceps tenodesis for a Type II SLAP tear yields superior clinical outcomes and lower reoperation rates compared to an arthroscopic SLAP repair.

Question 75

When performing a reverse total shoulder arthroplasty (RTSA), optimal positioning of the glenoid baseplate is critical to prevent scapular notching. Which of the following baseplate configurations is most effective in minimizing this complication?

Explanation

Placing the glenoid baseplate with an inferior tilt and neutral version minimizes inferior scapular notching in RTSA. It reduces the mechanical impingement of the humeral component against the scapular neck during adduction.

Question 76

During a posterior-stabilized total knee arthroplasty, trial components are placed. The knee is fully balanced and stable in full extension, but tight in 90 degrees of flexion with restricted range of motion. Which of the following is the most appropriate next step to balance the knee?

Explanation

A tight flexion gap with a balanced extension gap requires downsizing the femoral component using an anterior referencing system to remove more posterior condylar bone. Decreasing the polyethylene thickness would inappropriately loosen the extension gap.

Question 77

A 28-year-old professional volleyball player presents with insidious onset of right shoulder weakness. On examination, he has full active abduction and forward elevation, but profound weakness in external rotation with the arm at the side. Muscle atrophy is isolated to the infraspinatus fossa. Where is the most likely site of neurologic compression?

Explanation

Compression of the suprascapular nerve at the spinoglenoid notch affects only the infraspinatus muscle, leading to isolated external rotation weakness. Compression at the suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 78

A 45-year-old female sustains an acute medial meniscus posterior root tear. Biomechanically, this injury is most equivalent to which of the following?

Explanation

A medial meniscus posterior root tear disrupts the hoop stresses of the meniscus, causing extrusion under load. Biomechanically, this completely abolishes the load-sharing function of the meniscus, equivalent to a total meniscectomy.

Question 79

A 22-year-old rugby player has a history of recurrent anterior glenohumeral dislocations. Advanced imaging demonstrates 26% anterior glenoid bone loss and an engaging Hill-Sachs lesion. Which of the following procedures is the most appropriate surgical treatment?

Explanation

The Latarjet procedure (coracoid transfer) is indicated for patients with recurrent anterior instability and critical glenoid bone loss (typically >20-25%). Arthroscopic soft tissue repairs are prone to unacceptably high failure rates in this setting.

Question 80

During a medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability, identifying the correct femoral attachment (Schöttle point) is crucial. Where is this point located anatomically?

Explanation

The anatomic femoral origin of the MPFL is located in the saddle-shaped depression between the adductor tubercle proximally and the medial epicondyle distally. Non-anatomic graft placement is a leading cause of MPFL reconstruction failure.

Question 81

Six weeks after an uncomplicated anatomic total shoulder arthroplasty via a deltopectoral approach, a 68-year-old male presents with new-onset anterior shoulder pain, increased passive external rotation compared to his 2-week visit, and marked weakness in internal rotation. What is the most likely diagnosis?

Explanation

Subscapularis failure following TSA via a deltopectoral approach presents with increased passive external rotation, anterior shoulder pain, and weak internal rotation/positive belly-press test. It typically occurs within the first 6-8 weeks postoperatively.

Question 82

A 30-year-old male presents to the trauma bay following a motorcycle collision. Examination reveals a grossly deformed right knee which is subsequently reduced. Palpable dorsalis pedis and posterior tibial pulses are present post-reduction. What is the most appropriate next step in management regarding his vascular status?

Explanation

Following a knee dislocation, even with palpable pulses post-reduction, ABIs must be measured to rule out occult intimal injury to the popliteal artery. If the ABI is <0.9 or pulses are asymmetric, a CTA is indicated.

Question 83

A 32-year-old bodybuilder feels a pop in his anterior axillary fold while performing a heavy bench press. He is diagnosed with a complete pectoralis major rupture. Which of the following best describes the anatomic location where this injury most commonly occurs?

Explanation

The vast majority of pectoralis major ruptures in weightlifters occur as avulsions at the tendinous insertion onto the lateral lip of the bicipital groove of the humerus. These injuries typically happen during eccentric contraction.

Question 84

A patient presents with lateral knee pain and instability after a hyperextension injury. The dial test shows 15 degrees of increased external rotation on the injured side at 30 degrees of knee flexion, but symmetric external rotation at 90 degrees of knee flexion. What does this examination finding indicate?

Explanation

An increase in external rotation >10 degrees at 30 degrees of flexion but symmetric rotation at 90 degrees indicates an isolated posterolateral corner (PLC) injury. Combined PCL and PLC injuries show increased external rotation at both 30 and 90 degrees.

Question 85

A 58-year-old laborer with pseudoparalysis of the shoulder is found to have a massive, irreparable tear of the supraspinatus and infraspinatus with an intact subscapularis and no glenohumeral arthritis. A superior capsular reconstruction (SCR) is planned. Between which two bony landmarks is the graft typically attached?

Explanation

Superior capsular reconstruction utilizes a dermal allograft or autograft anchored medially to the superior glenoid and laterally to the greater tuberosity. This restores the superior restraints of the glenohumeral joint, depressing the humeral head to improve kinematics.

Question 86

A 60-year-old patient with isolated medial compartment knee osteoarthritis is being evaluated for a unicompartmental knee arthroplasty (UKA). Which of the following is considered a classic contraindication for a medial UKA?

Explanation

A fixed, non-correctable varus deformity is a contraindication to a medial UKA, as releasing ligaments to correct the deformity in UKA will lead to instability. An intact ACL and correctable deformity are prerequisites for the procedure.

Question 87

A 25-year-old overhead athlete presents with deep shoulder pain and clicking.

Diagnostic arthroscopy confirms a Type II SLAP lesion. What is the most widely accepted initial surgical management for this specific injury in this demographic if conservative measures fail?

Explanation

In young overhead athletes (<35 years old) with a Type II SLAP lesion, arthroscopic superior labral repair to the glenoid is the standard of care to restore normal shoulder kinematics. Biceps tenodesis is typically reserved for older patients or revision cases.

Question 88

A 65-year-old female presents 14 months after a posterior-stabilized total knee arthroplasty complaining of a painful "catching" sensation. The symptom occurs as she actively extends her knee from a flexed position, typically around 30 to 45 degrees of flexion. What is the most likely underlying pathology?

Explanation

Patellar clunk syndrome is a complication of posterior-stabilized TKA designs, characterized by a fibrosynovial nodule forming at the superior pole of the patella. As the knee extends, the nodule catches in the intercondylar notch of the femoral component.

Question 89

A 24-year-old manual laborer sustains a Grade III acromioclavicular (AC) joint separation. Biomechanical studies indicate that the primary restraint to superior translation of the distal clavicle is provided by which of the following structures?

Explanation

The conoid ligament is the primary restraint to superior translation of the distal clavicle. The trapezoid ligament provides the primary restraint to axial compression, while the AC ligaments provide horizontal stability.

Question 90

A 14-year-old boy presents with vague, poorly localized knee pain and intermittent swelling. Radiographs reveal an osteochondritis dissecans (OCD) lesion. In which of the following locations is this lesion most commonly found?

Explanation

The classic and most common location for osteochondritis dissecans (OCD) of the knee is the lateral aspect of the medial femoral condyle (seen in over 70% of cases). This location can be visualized on a notch view radiograph.

Question 91

Adhesive capsulitis of the shoulder is characterized by dense fibrosis and contracture of the glenohumeral capsule. Which of the following cytokines is most strongly implicated in the fibroblastic proliferation seen in this condition?

Explanation

Transforming growth factor-beta (TGF-beta) is the primary cytokine responsible for driving the robust fibroblastic proliferation and collagen deposition characteristic of adhesive capsulitis. It is a key mediator in capsular fibrosis.

Question 92

The anterior cruciate ligament (ACL) is composed of two distinct functional bundles: the anteromedial (AM) bundle and the posterolateral (PL) bundle. Which of the following best describes their tensioning behavior during knee range of motion?

Explanation

The AM bundle of the ACL is tense in knee flexion and is the primary restraint to anterior tibial translation at 90 degrees. The PL bundle is tense in knee extension and provides significant rotatory stability.

Question 93

A 75-year-old female presents with severe pseudoparalysis and severe glenohumeral arthritis secondary to massive rotator cuff arthropathy. Radiographs reveal the 'snowcap' sign. Which of the following findings is an absolute contraindication to performing a shoulder hemiarthroplasty in this patient?

Explanation

Coracoacromial (CA) arch insufficiency is an absolute contraindication to hemiarthroplasty in rotator cuff tear arthropathy. Without the CA arch, a hemiarthroplasty will lead to uncontained anterosuperior escape of the humeral head, necessitating a reverse total shoulder arthroplasty.

Question 94

A 68-year-old male with a history of chronic renal failure falls directly onto a flexed knee. He is unable to perform a straight leg raise. Lateral radiographs demonstrate a high-riding patella (patella alta). What is the most likely diagnosis?

Explanation

A high-riding patella (patella alta) on a lateral radiograph, combined with an inability to actively extend the knee, is pathognomonic for a patellar tendon rupture. Quadriceps tendon ruptures present with a low-riding patella (patella baja).

Orthopaedic Surgery Board Exam Review: ABOS Part I & AAOS OITE Prep Questions | Part 22210

ABOS Part I Orthopedic Review: Shoulder & Knee Pathology, Imaging, & Reconstruction | Part 22167

Key Takeaway

ABOS Part I Orthopedic Review: Shoulder & Knee Pathology, Imaging, & Reconstruction | Part 22167

Chapter Index