Comprehensive ABOS Part I & II Orthopedic Review MCQs

Question 1

A candidate is preparing for the ABOS Part II Oral Examination. They recall stories from senior residents about examiners who would intentionally ask obscure basic science questions and engage in aggressive, rapid-fire questioning to test a candidate's resilience under pressure. Based on the provided case, which of the following statements best reflects the current philosophy of the structured oral examination compared to these historical accounts?

Explanation

Correct Answer: C

The provided case explicitly states that the new structured oral examination methods were introduced because the old methods (rapid quick-fire questions, excessive probing) 'more often terrified and stressed candidates into performing poorly.' It emphasizes that the current exam is a 'fair, consistent, valid and reliable method of assessment' and that examiners are 'not testing a candidate’s ability to stand up to rapid quick-fire questions and excessive probing.' Instead, the focus is on 'probing the higher cognitive processes of candidates.' Therefore, option C accurately reflects this shift.

Option A is incorrect because the case clearly states that the new exam is not testing a candidate's ability to stand up to rapid quick-fire questions and excessive probing, which was the norm in the late 1990s.

Option B is incorrect as the case highlights a move away from confrontational styles, emphasizing that examiners 'must be polite at all times' and that 'harassment of candidates is ever allowed and will be stopped by the co-examiner.'

Option D is incorrect because while the case mentions that some senior examiners took 'perverse pleasure in asking impossible basic science questions,' it does not state that basic science is entirely excluded. Rather, it implies that the nature and intent of such questions have changed to be part of a 'representative sample of all the appropriate curriculum outcomes and a representative sample of all the curriculum content' through blueprinting.

Option E is incorrect as the case explicitly states that examiners 'are not allowed to give much candidate feedback at all such as ‘well done’ or ‘excellent’' to maintain consistency and fairness across all candidates.

Question 2

An ABOS examiner is undergoing training for the new structured oral examination. During a discussion, they express concern that the new format might limit their ability to thoroughly assess a candidate's depth of knowledge by preventing 'robust discussions.' Based on the case, how should this concern be addressed?

Explanation

Correct Answer: C

The case directly addresses this point, stating, 'A good robust discussion is a grey area; it may quickly turn into a robust argument and is probably best avoided.' This indicates that while the intent might be to probe knowledge, the risk of such discussions becoming counterproductive and stressful for the candidate outweighs their potential benefit in the new structured oral format.

Option A is incorrect because the case advises against 'robust discussions' due to their potential to turn into arguments and stress candidates, contrasting with the old norm of 'bringing out the best' through rapid-fire questions.

Option B is incorrect as the case explicitly states that examiners are 'not testing a candidate’s ability to stand up to rapid quick-fire questions and excessive probing,' indicating a move away from such techniques.

Option D is incorrect as the case does not mention candidate-initiated robust discussions or any specific conditions under which they are encouraged.

Option E is incorrect because the case frames the changes as an application of 'latest education evidence' to ensure 'best educational practice' and improve validity and reliability, not merely as a concession to political correctness at the expense of comprehensive assessment. The emphasis is on assessing 'higher cognitive processes' through fair methods.

Question 3

A candidate fails the ABOS Part II Oral Examination. They feel the exam was unfair because they were asked several complex questions about a rare orthopedic condition that was not covered extensively in their residency program. Based on the principles outlined in the case, what is the primary tool used in the new structured oral examination to address such concerns about content coverage?

Explanation

Correct Answer: B

The case states, 'An assessment blueprint confirms that the exam tests a representative sample of all the appropriate curriculum outcomes and a representative sample of all the curriculum content.' It further emphasizes that the blueprint is 'an essential tool for examination planning and ensure content validity of the exam.' This tool is designed precisely to prevent situations where a candidate might feel unfairly tested on obscure or unrepresented content.

Option A is incorrect because the case describes the traditional viva voce as having issues with 'examiner leniency,' implying a move towards more standardized and less subjective assessment.

Option C is incorrect as the case does not mention candidate feedback mechanisms for challenging questions, focusing instead on the internal structure and fairness of the exam design.

Option D is incorrect while the co-examiner's role is mentioned in preventing harassment, the case does not specify their role in monitoring content scope during the exam itself, rather the blueprint addresses this proactively.

Option E is incorrect the case mentions 'impossible basic science questions' as a characteristic of the old viva, but the solution is blueprinting for content validity, not merely a forbidden list.

Question 4

During an ABOS Part II Oral Examination, a candidate provides an excellent answer to a challenging question. The examiner, impressed by the candidate's insight, is tempted to say, 'That was an excellent response, well done!' Based on the guidelines for the new structured oral examination, what is the appropriate action for the examiner?

Explanation

Correct Answer: C

The case explicitly states, 'The examiners have to remind the candidate which oral they are sitting in order to give them time to settle and must be polite at all times. They are not allowed to give much candidate feedback at all such as ‘well done’ or ‘excellent’ and certainly no harassment of candidates is ever allowed and will be stopped by the co-examiner.' This guideline is in place to ensure consistency and fairness across all candidates, preventing any perceived bias or differential treatment based on immediate performance.

Option A is incorrect because the guidelines explicitly forbid giving such feedback during the exam.

Option B is incorrect there is no mention of co-examiner approval for feedback; the rule is a general prohibition.

Option D is incorrect the case does not provide for giving feedback post-session, only that it's not allowed during the exam.

Option E is incorrect giving positive feedback is a form of assessment interaction, but it is not described as a method for 'probing higher cognitive processes.' The case separates these two aspects of the exam.

Question 5

A new ABOS examiner is reviewing the educational evidence supporting the structured oral examination. They are particularly interested in how the new format addresses the historical issues of variability in assessment. According to the case, which characteristic of the new structured oral examination directly contributes to its improved consistency and reliability?

Explanation

Correct Answer: C

The case directly states, 'This has all changed with the introduction of blueprinting, structure and careful standard setting. The current exam is a fair, consistent, valid and reliable method of assessment.' These three elements are presented as the foundational changes that address the historical variability in assessment content, item difficulty, and examiner leniency.

Option A is incorrect as the case describes the old viva as having issues with 'examiner leniency' and emphasizes standardization, not individualized adjustments based on stress levels.

Option B is incorrect while 'political correctness is better observed these days,' it is presented as one aspect of examiner conduct, not the primary driver for the fundamental structural changes that ensure consistency and reliability. The core drivers are blueprinting, structure, and standard setting based on 'latest education evidence.'

Option D is incorrect the case advises that 'robust discussion' is 'probably best avoided' due to the risk of it turning into an argument, indicating it does not contribute to improved consistency or reliability.

Option E is incorrect the case mentions 'impossible basic science questions' as a problem in the old viva, but does not state that all basic science questions have been eliminated. Instead, blueprinting ensures a 'representative sample' of curriculum content, which would include relevant basic science.

Question 6

A candidate is informed that they are about to begin their structured oral examination. They are feeling anxious and unsure of the exact format. Based on the case, what specific action are the examiners required to take at the beginning of the examination to help the candidate settle?

Explanation

Correct Answer: C

The case explicitly states, 'The examiners have to remind the candidate which oral they are sitting in order to give them time to settle and must be polite at all times.' This specific instruction is designed to help reduce candidate anxiety and ensure they understand the context of the examination.

Option A is incorrect as the case does not mention providing a curriculum overview at the start of the exam.

Option B is incorrect because examiners are 'not allowed to give much candidate feedback at all such as ‘well done’ or ‘excellent’' during the exam.

Option D is incorrect 'robust discussions' are 'probably best avoided' and are not a settling mechanism.

Option E is incorrect the case does not mention any allowance for candidates to challenge question difficulty during the exam.

Question 7

The ABOS Board is reviewing the effectiveness of the new structured oral examination. A key metric for success is ensuring that the exam adequately covers the breadth of orthopedic knowledge expected of a board-certified surgeon. What concept, highlighted in the case, is crucial for ensuring this comprehensive coverage?

Explanation

Correct Answer: C

The case states, 'An assessment blueprint confirms that the exam tests a representative sample of all the appropriate curriculum outcomes and a representative sample of all the curriculum content.' It further emphasizes that the blueprint is 'an essential tool for examination planning and ensure content validity of the exam.' This directly addresses the need for comprehensive and appropriate coverage of the curriculum.

Option A is incorrect as examiner leniency was a characteristic of the old viva and contributed to inconsistency, not comprehensive coverage.

Option B is incorrect while co-examiners have a role (e.g., preventing harassment), the case does not describe their primary function as ensuring curriculum breadth through real-time feedback to the primary examiner.

Option D is incorrect the case does not state that all basic science questions are eliminated; rather, blueprinting ensures appropriate sampling of all content, which would include relevant basic science.

Option E is incorrect 'robust arguments' are explicitly advised against, as they are detrimental to the examination process.

Question 8

A candidate is struggling during a structured oral examination, showing signs of significant stress. The primary examiner notices this and considers softening their questioning or offering a hint. Based on the case, what is the appropriate course of action for the primary examiner?

Explanation

Correct Answer: B

The case emphasizes that the new structured oral examination is a 'fair, consistent, valid and reliable method of assessment.' While examiners 'must be polite at all times' and 'harassment of candidates is ever allowed and will be stopped by the co-examiner,' there is no provision for softening questions or offering hints to individual candidates. Doing so would introduce variability and compromise the consistency and fairness of the assessment, which are core tenets of the new system. The goal is to assess higher cognitive processes under standardized conditions, not to adjust the difficulty for struggling candidates during the exam.

Option A is incorrect because while politeness is required, altering the exam for an individual candidate (softening questions, offering hints) would undermine the 'consistent' and 'fair' nature of the assessment. 'Political correctness' refers to conduct, not altering assessment standards.

Option C is incorrect the co-examiner's role is primarily to prevent harassment, not to take over questioning due to candidate stress.

Option D is incorrect the case does not mention provisions for breaks during the examination for candidate composure.

Option E is incorrect while the exam is designed to be less stressful, simply reminding the candidate of this is not an 'action' to be taken by the examiner in response to observed stress that would alter the exam's consistency.

Question 9

A senior orthopedic surgeon, reflecting on their own board certification experience from the late 1990s, notes that their viva voce exam felt highly subjective, with different candidates receiving vastly different experiences. Based on the case, which of the following aspects of the new structured oral examination directly addresses this historical issue of subjectivity and variability?

Explanation

Correct Answer: D

The case explicitly states that the traditional viva voce suffered from variability in 'assessment content, item difficulty and examiner leniency.' It then introduces the assessment blueprint as a tool that 'confirms that the exam tests a representative sample of all the appropriate curriculum outcomes and a representative sample of all the curriculum content' and is 'essential... to ensure content validity.' This directly addresses the subjectivity and variability in what was tested.

Option A is incorrect while politeness improves the candidate experience, it doesn't directly address the variability in what is assessed or how it's scored.

Option B is incorrect the prohibition on feedback contributes to consistency in examiner conduct but doesn't directly solve the problem of variable content or difficulty.

Option C is incorrect applying education evidence is the overall approach to improving the exam, but the specific mechanism for addressing content variability is the blueprint.

Option E is incorrect avoiding robust discussions prevents arguments and stress, contributing to a better experience, but doesn't directly ensure that the content sampled is consistent and representative across candidates.

Question 10

The ABOS is considering further refinements to the structured oral examination. A proposal is made to reintroduce elements of rapid-fire questioning, arguing that it effectively probes a candidate's ability to think quickly under pressure, which is a critical skill for surgeons. Based on the provided case, what is the most likely response from the examination board regarding this proposal?

Explanation

Correct Answer: C

The case explicitly states, 'Examiners are not testing a candidate’s ability to stand up to rapid quick-fire questions and excessive probing. This was the norm in the late 1990s and could bring out the best in a candidate – has political correctness gone too far these days? In truth these methods were old fashioned and more often terrified and stressed candidates into performing poorly.' This strong condemnation of rapid-fire questioning indicates that the board would reject such a proposal, as it goes against the core philosophy of the new structured oral exam.

Option A is incorrect because the case states these methods 'more often terrified and stressed candidates into performing poorly,' not that they are proven to assess higher cognitive processes effectively in the current framework.

Option B is incorrect while blueprinting ensures content validity, the method of rapid-fire questioning itself is deemed detrimental, regardless of content adherence.

Option D is incorrect there is no indication that such methods would be selectively applied; the general principle is to avoid them.

Option E is incorrect while a co-examiner prevents harassment, the issue with rapid-fire questioning is its inherent stress-inducing nature and its ineffectiveness in assessing candidates fairly, not just the risk of harassment.

Question 11

A 35-year-old male presents after a high-energy motor vehicle collision with hemodynamic instability, a palpable hematoma in the left groin, and a pelvic ring injury classified as Young-Burgess LC-III. What is the most appropriate initial management step after fluid resuscitation and basic life support?

Explanation

Correct Answer: C

In hemodynamically unstable patients with pelvic ring injuries, the priority after fluid resuscitation and basic life support is to mechanically stabilize the pelvis to tamponade hemorrhage. A pelvic binder (or sheet) provides rapid temporary mechanical stabilization, reducing the volume of the pelvic cavity and potentially controlling venous bleeding. While angiography is often needed for arterial bleeds, mechanical stabilization is typically the immediate first step. External fixation is a more definitive form of stabilization but may not be as rapid to apply as a binder. Laparotomy is indicated for suspected intra-abdominal hemorrhage, which is a separate consideration from direct pelvic bleeding in LC-III injuries.

Question 12

A 68-year-old female undergoes a cemented total hip arthroplasty. Intraoperatively, she experiences sudden hypoxia, hypotension, and a drop in end-tidal CO2. What is the most likely diagnosis?

Explanation

Correct Answer: C

The constellation of sudden hypoxia, hypotension, and a drop in end-tidal CO2 (due to decreased pulmonary blood flow) occurring during cemented arthroplasty, particularly during femoral canal pressurization, is highly suggestive of Bone Cement Implantation Syndrome (BCIS). This syndrome is thought to be caused by the release of intramedullary contents (fat, bone marrow, air) into the systemic circulation, leading to pulmonary vaso-occlusion and release of vasoactive mediators. While pulmonary embolism is a differential, the acute intraoperative timing with cementing makes BCIS the most likely diagnosis.

Question 13

A 55-year-old male presents with progressive bilateral neurogenic claudication, worse on standing and walking, relieved by sitting or leaning forward. MRI shows severe lumbar spinal stenosis at L4/5. Which surgical approach is generally considered the gold standard for this condition if conservative measures fail?

Explanation

Correct Answer: D

For symptomatic lumbar spinal stenosis that causes neurogenic claudication and has failed conservative management, a decompressive laminectomy (with or without associated facetectomy or foraminotomy) is considered the gold standard surgical procedure. Its primary aim is to relieve neural compression directly. Fusion procedures (ALIF, TLIF) are typically reserved for cases with associated instability, significant deformity, or iatrogenic instability created by extensive decompression. Microdiscectomy is primarily for disc herniation, and artificial disc replacement is for discogenic back pain without stenosis or instability.

Question 14

A 6-month-old infant is diagnosed with a dislocatable hip on the Ortolani maneuver. Radiographs show a dislocated left hip with an acetabular index of 35 degrees. What is the most appropriate initial treatment?

Explanation

Correct Answer: A

For an infant aged 0-6 months (and often up to 9 months) with a dislocatable or reducible dislocated hip (Developmental Dysplasia of the Hip - DDH), the Pavlik harness is the gold standard initial treatment. It maintains the hips in gentle flexion and abduction, promoting concentric reduction and encouraging normal acetabular development. Closed reduction under general anesthesia and spica casting are typically reserved for older infants or failures of Pavlik harness treatment. Open reduction is indicated for irreducible dislocations.

Question 15

A 28-year-old semi-professional football player sustains a non-contact injury to his knee during a game, describing a 'pop' and immediate swelling. Lachman test is positive with a soft endpoint. MRI confirms an isolated ACL tear. He wishes to return to high-level sport. What is the primary goal of ACL reconstruction in this athlete?

Explanation

Correct Answer: B

The primary goal of ACL reconstruction in a young, active athlete, especially one aspiring to return to high-level sports, is to restore the normal kinematics and anterior-posterior/rotational stability of the knee. This functional stability is crucial to prevent episodes of giving way and allow the athlete to perform cutting, pivoting, and jumping activities confidently. While preventing meniscal injury and reducing the risk of osteoarthritis are important secondary benefits, they are consequences of achieving knee stability. Achieving full range of motion and early weight-bearing are rehabilitation goals rather than the direct primary surgical objective.

Question 16

A 14-year-old male presents with right distal femur pain and swelling for 3 months. Radiographs show a lytic lesion with a Codman's triangle and sunburst periosteal reaction. Biopsy confirms osteosarcoma. What is the most critical investigation for staging and treatment planning?

Explanation

Correct Answer: B

Osteosarcoma has a significant propensity for pulmonary metastasis, which is the most common site of distant spread. Therefore, a CT scan of the chest is the most critical investigation for staging, as the presence of lung metastases significantly impacts prognosis and dictates the extent of systemic treatment (e.g., neoadjuvant chemotherapy). While MRI of the affected limb is crucial for local staging and surgical planning, and a bone scan for other osseous metastases, identifying pulmonary metastases is paramount for systemic staging and overall treatment strategy.

Question 17

A 40-year-old carpenter falls onto an outstretched hand and complains of severe wrist pain, particularly on the ulnar side. Physical exam reveals tenderness in the 'fovea' between the extensor carpi ulnaris and the flexor carpi ulnaris. X-rays are normal. What is the most likely injury?

Explanation

Correct Answer: D

A fall onto an outstretched hand (FOOSH) can cause various wrist injuries. Ulnar-sided wrist pain, especially with tenderness in the 'fovea' (the soft spot distal to the ulnar styloid between the ECU and FCU tendons), is a classic clinical sign of a Triangular Fibrocartilage Complex (TFCC) tear, particularly involving its foveal attachment. Normal X-rays are common as the TFCC is a soft tissue structure. While other carpal injuries like lunotriquetral tears can cause ulnar wrist pain, fovea tenderness is highly specific for TFCC pathology.

Question 18

A 60-year-old female presents with progressive pain and deformity in her hindfoot, worse with activity. She has a flexible flatfoot deformity with abduction of the forefoot. Examination reveals tenderness along the medial ankle and inability to perform a single-leg heel raise. What is the most likely diagnosis?

Explanation

Correct Answer: C

This clinical picture is highly characteristic of Posterior Tibial Tendon Dysfunction (PTTD), specifically Stage II. Key features include an adult-acquired flexible flatfoot deformity, forefoot abduction (the 'too many toes' sign), pain and tenderness along the course of the posterior tibial tendon (medial ankle), and inability to perform a single-leg heel raise (indicating significant weakness of the posterior tibial tendon, which is crucial for dynamic arch support). While the spring ligament is often involved in the progression of the deformity, PTTD is the overarching diagnosis.

Question 19

During a total knee arthroplasty, the surgeon aims to achieve a balanced soft tissue envelope. What principle describes the ideal state where ligamentous tension is uniform throughout the range of motion?

Explanation

Correct Answer: E

Isometry, in the context of knee kinematics and ligamentous balance, refers to the property where the distance between the origins and insertions of the collateral ligaments remains relatively constant throughout the range of motion. Achieving this during total knee arthroplasty (via appropriate implant positioning and soft tissue releases) is crucial for ensuring uniform ligamentous tension, which contributes significantly to knee stability, kinematics, and overall function. Ligament balancing is the technique used to achieve this.

Question 20

A 48-year-old male sustains a comminuted, intra-articular fracture of the distal radius (AO type C3) with significant metaphyseal comminution and displacement. He is an active manual labourer. What is the most appropriate surgical treatment to optimize functional outcomes in this patient?

Explanation

Correct Answer: D

For unstable, comminuted, intra-articular distal radius fractures (AO type C3), especially in active individuals requiring optimal functional outcomes and early return to work, volar locking plate fixation has become the preferred surgical treatment. It provides strong, stable fixation that allows for accurate anatomical reduction (particularly of the articular surface) and facilitates early range of motion, which is crucial for preventing stiffness and achieving the best possible functional recovery. Other methods like K-wires or external fixation are typically less stable for such complex fractures or may not allow for immediate mobilization.

Question 21

A candidate preparing for a high-stakes orthopedic oral examination (e.g., FRCS, AAOS, OITE) is advised to prioritize a comprehensive understanding of core orthopedic principles. Which of the following preparation strategies is MOST effective for solidifying foundational knowledge while simultaneously developing the nuanced communication skills required for an oral examination?

Explanation

Correct Answer: C

Structured, peer-led viva practice sessions are invaluable. They not only force the candidate to articulate their knowledge and reasoning aloud, mirroring the exam environment, but also allow for immediate feedback on communication style, logical flow, and depth of understanding. This active recall and explanation solidifies foundational knowledge far more effectively than passive memorization or sole reliance on past papers without the oral practice component. Commercial courses can supplement, but not replace, active personal and peer-group preparation which integrates verbalization and critical feedback.

Question 22

During an oral examination, an examiner asks a highly specialized question outside your immediate expertise. Which of the following responses is MOST appropriate and professional?

Explanation

Correct Answer: D

The most professional and constructive approach is to acknowledge the specific limitation directly but not completely shut down. Demonstrating an understanding of related foundational principles, a logical problem-solving approach, or indicating where one would seek the answer (e.g., specific literature, consultation) shows intellectual curiosity, critical thinking, and a safe approach to patient care, even when faced with an unfamiliar scenario. Bluffing or excessive apologies are detrimental to one's credibility and professionalism.

Question 23

You are presented with a simulated clinical scenario: a 45-year-old male with a displaced distal radius fracture. When asked to 'discuss your management,' which initial framework demonstrates the MOST structured and comprehensive approach expected by an examiner?

Explanation

Correct Answer: C

Examiners seek a structured, systematic approach that demonstrates a holistic understanding of patient care, not just technical surgical skills. An initial framework that covers the entire patient journey – from diagnosis (history, exam, investigations) through treatment decisions (non-op vs. op), patient communication (consent), and post-treatment considerations (post-op care, rehabilitation, complications) – demonstrates comprehensive clinical reasoning. While classification and latest research are important, they fit within this broader framework, not as the initial statement of management. Delaying an answer or over-focusing on a single aspect can suggest a lack of structured thinking.

Question 24

During your explanation of a complex surgical approach, the examiner repeatedly interrupts with challenging follow-up questions. What is the MOST effective strategy to maintain composure and demonstrate mastery?

Explanation

Correct Answer: C

Examiners often use interruptions to test a candidate's ability to think on their feet, manage pressure, and maintain a structured thought process. The most effective strategy is to acknowledge the interruption, address the specific question concisely, and then gracefully pivot back to your original, planned answer structure. This demonstrates flexibility, responsiveness, and an ability to stay organized under pressure. Ignoring or directly challenging the examiner is unprofessional and detrimental to the candidate's perceived professionalism and ability to handle pressure.

Question 25

When discussing a controversial management decision (e.g., choice of implant, timing of surgery, non-operative vs. operative) in an oral exam, how should a candidate MOST effectively integrate Evidence-Based Medicine (EBM) into their response?

Explanation

Correct Answer: C

A strong candidate in an oral exam demonstrates the ability to critically appraise and integrate EBM into clinical decision-making. This involves acknowledging areas of controversy, citing high-level evidence (e.g., landmark RCTs, systematic reviews) to support a chosen approach, and crucially, explaining how this evidence is applied or modified for the individual patient. This approach shows critical thinking, knowledge of the literature, and the ability to tailor treatment. Avoiding discussion or relying on anecdote demonstrates a lack of critical appraisal skills. Simply listing studies without synthesis is insufficient.

Question 26

An examiner asks you to 'talk me through a total hip arthroplasty.' Which aspect of your answer should you prioritize to demonstrate a comprehensive understanding, beyond just the technical steps?

Explanation

Correct Answer: C

While technical steps, biomechanics, and approaches are important, a comprehensive understanding of a procedure in an oral exam extends to the entire patient journey. Prioritizing patient selection, indications, contraindications, pre-operative planning, and post-operative care, alongside intra-operative details and complication management, demonstrates a holistic clinical perspective expected of a board-certified orthopedic surgeon. This shows an understanding of the 'why' and 'what next', not just the 'how'.

Question 27

You are presented with a difficult ethical scenario involving a patient refusing a life-saving amputation. How should you MOST appropriately structure your response?

Explanation

Correct Answer: C

Ethical dilemmas require a structured approach grounded in medical ethics. Discussing the core principles (autonomy, beneficence, non-maleficence, justice) demonstrates a foundational understanding. Crucially, assessing patient capacity to make informed decisions, exploring their reasoning, and involving a multidisciplinary team (e.g., palliative care, psychiatry, social work) and ethics committee consultation showcases a comprehensive, patient-centered, and legally sound approach to complex ethical situations. Stating personal beliefs or focusing solely on legal aspects without ethical deliberation is insufficient.

Question 28

During a viva, an examiner challenges your chosen management plan aggressively, stating 'That's not how we do things in my practice.' What is the MOST appropriate and professional response?

Explanation

Correct Answer: C

This scenario tests your ability to handle pressure, respect authority, and stand by evidence-based reasoning. The most professional approach is to respectfully acknowledge the examiner's input, demonstrate that you've heard their perspective, but then clearly and concisely reiterate the scientific rationale or evidence supporting your own plan. Offering to hear their alternative or discuss nuances demonstrates maturity and an open, learning mindset, while avoiding confrontation. Blindly agreeing or becoming defensive are both poor responses.

Question 29

When discussing potential post-operative rehabilitation for a complex orthopedic injury, what aspect should you emphasize to demonstrate a comprehensive understanding of patient recovery?

Explanation

Correct Answer: C

A comprehensive understanding of rehabilitation involves recognizing it as an integral part of the overall management plan, guided by biological healing and functional goals. A phased approach that incorporates specific milestones, addresses potential barriers (like patient compliance), and acknowledges the collaborative role of the multidisciplinary team demonstrates a holistic and practical grasp of patient recovery. Simply listing immobilization times is insufficient.

Question 30

An examiner asks a very open-ended question, such as 'Tell me about fractures around the knee.' How should you initiate your response to provide structure and depth?

Explanation

Correct Answer: C

Open-ended questions test your ability to structure a broad topic. Initiating with a categorized overview demonstrates organized thinking and control of the subject matter. It shows you can distill a vast topic into manageable sections, and then offers the examiner the opportunity to guide you to a specific area of interest, making your answer relevant and tailored. Avoiding structure or immediately narrowing the topic is less effective.

Question 31

A 12-year-old obese male presents with an acute-on-chronic unstable slipped capital femoral epiphysis (SCFE). Which of the following intraoperative maneuvers or surgical decisions carries the highest risk for inducing avascular necrosis (AVN) of the femoral head?

Explanation

Forceful or anatomic closed reduction of an unstable SCFE significantly increases the risk of avascular necrosis due to further disruption of the already compromised retinacular vessels. Current guidelines advocate for in situ fixation or controlled open reduction techniques like the modified Dunn procedure.

Question 32

A 28-year-old male sustains a vertically oriented (Pauwels III) femoral neck fracture. Which of the following biomechanical factors best explains the high rate of nonunion and hardware failure in this fracture pattern?

Explanation

Pauwels III fractures have a vertical orientation (angle greater than 50 degrees), which translates weight-bearing loads into high shear forces rather than compressive forces. This leads to instability, varus collapse, and an increased risk of nonunion.

Question 33

A 65-year-old male presents with progressive clumsiness in his hands and a broad-based gait. MRI reveals multilevel cervical spondylotic myelopathy from C3 to C6 with preserved cervical lordosis. There is no evidence of instability on flexion-extension radiographs. What is the most appropriate surgical intervention?

Explanation

Cervical laminoplasty is ideal for multilevel (3 or more) cervical myelopathy in the presence of preserved cervical lordosis and the absence of instability. It avoids the morbidity of multilevel anterior fusions while effectively decompressing the spinal cord.

Question 34

A 72-year-old female experiences her third posterior dislocation following a primary total hip arthroplasty performed via a posterior approach. Radiographs demonstrate the acetabular component is placed in 5 degrees of retroversion and 45 degrees of abduction. The femoral component is well-fixed with 15 degrees of anteversion. What is the most appropriate definitive management?

Explanation

The acetabular component is retroverted, which is the primary driver of this patient's recurrent posterior dislocations. Revision of the acetabular shell to correct the version (target 15-20 degrees of anteversion) is the definitive mechanical solution.

Question 35

A 45-year-old manual laborer presents with chronic wrist pain. Radiographs reveal a scaphoid nonunion advanced collapse (SNAC) pattern with degenerative changes extending to the capitolunate joint (SNAC Stage III). The radiolunate joint is preserved. What is the most appropriate surgical treatment?

Explanation

In SNAC Stage III, arthritis involves the capitolunate joint, making proximal row carpectomy (PRC) contraindicated due to the wear on the capitate head. Scaphoid excision with a four-corner fusion reliably relieves pain while preserving functional, albeit reduced, wrist motion.

Question 36

A 45-year-old hemodynamically unstable male presents after a motorcycle accident with an APC-III pelvic ring injury. A pelvic binder is applied, and he receives 2 units of packed RBCs, but his systolic blood pressure remains 70 mmHg. A FAST exam is negative. What is the most appropriate next step in management?

Explanation

In a hemodynamically unstable patient with a pelvic ring injury and a negative FAST, the source of bleeding is presumed to be the pelvis. Preperitoneal packing or angiography (depending on institutional protocol and immediate availability) is the next definitive step to control hemorrhage.

Question 37

A 65-year-old female presents with a draining sinus tract over her right knee 6 weeks after a primary total knee arthroplasty. Cultures from a recent aspiration grew Methicillin-resistant Staphylococcus aureus (MRSA). According to current standards for periprosthetic joint infection (PJI), what is the most appropriate surgical treatment?

Explanation

The presence of a draining sinus tract represents a chronic periprosthetic joint infection, which is a contraindication for DAIR. A two-stage exchange arthroplasty is the gold standard treatment for chronic PJI, especially with virulent organisms like MRSA.

Question 38

A 13-year-old obese male presents with left groin pain and an inability to bear weight on the left leg for the past 24 hours. Radiographs confirm a severe left slipped capital femoral epiphysis (SCFE). Which of the following management strategies carries the lowest risk of avascular necrosis (AVN) while addressing the pathology?

Explanation

This is an unstable SCFE (inability to bear weight), which has a high rate of AVN. Urgent gentle in-situ pinning, often accompanied by intracapsular decompression to lower tamponade pressure, is the standard of care. Forceful reduction significantly increases AVN risk.

Question 39

A 60-year-old male presents with progressive hand clumsiness and broad-based gait. MRI shows severe cervical spinal stenosis at C4-C6. Upright lateral radiographs demonstrate a fixed rigid cervical kyphosis of 20 degrees. What is the most appropriate surgical approach?

Explanation

In the setting of cervical myelopathy with a fixed kyphotic deformity, posterior-only decompression (laminectomy or laminoplasty) is contraindicated as the spinal cord will not drift backward, and kyphosis may worsen. An anterior approach allows for direct decompression of anterior pathology and correction of kyphosis.

Question 40

A 25-year-old male presents with a 6-month-old scaphoid proximal pole nonunion. MRI demonstrates avascular necrosis of the proximal pole, but there are no signs of radiocarpal arthritis. What is the most appropriate surgical treatment?

Explanation

For a scaphoid nonunion with AVN of the proximal pole and no arthritic changes, vascularized bone grafting (such as a pedicled distal radius graft or free medial femoral condyle graft) provides the best union rates. Salvage procedures (four-corner fusion, PRC) are reserved for cases with arthritis.

Question 41

When performing an incisional biopsy of a suspected soft-tissue sarcoma in the anterior thigh, which of the following principles must be strictly followed to avoid compromising future limb-salvage surgery?

Explanation

Biopsy tracts for suspected sarcomas must be excised during definitive surgery. Therefore, a longitudinal incision directly over the mass, avoiding transverse extensions and minimizing flap elevation or hematoma formation, is critical to prevent tumor seeding and allow future en bloc resection.

Question 42

A 9-year-old boy (Tanner stage 1) sustains a complete anterior cruciate ligament (ACL) tear. He experiences recurrent instability despite bracing and physical therapy. What is the most appropriate surgical option?

Explanation

In a skeletal immature patient with significant growth remaining (Tanner stage 1), transphyseal drilling risks growth arrest and angular deformity. A physeal-sparing reconstruction utilizing the iliotibial band is indicated for recurrent instability.

Question 43

A 55-year-old diabetic patient presents with a red, hot, swollen unilateral foot. Peripheral pulses are bounding. Radiographs show soft tissue swelling but no fractures or dislocations. What is the most appropriate initial management for this suspected Eichenholtz "stage 0" Charcot arthropathy?

Explanation

Eichenholtz stage 0 Charcot arthropathy presents with acute inflammation but normal radiographs. It must be differentiated from infection. The standard of care to prevent catastrophic bony destruction is immediate offloading, typically with a total contact cast, until the acute inflammatory phase resolves.

Question 44

A 30-year-old male is admitted with a comminuted midshaft tibia fracture. Overnight, he develops pain out of proportion to the injury. His blood pressure is 110/70 mmHg. Direct measurement of the anterior compartment pressure is 45 mmHg. What is the "delta pressure" and what is the next step in management?

Explanation

The delta pressure is calculated as Diastolic BP minus Compartment Pressure (70 - 45 = 25 mmHg). A delta pressure less than 30 mmHg is highly sensitive for acute compartment syndrome, necessitating urgent four-compartment fasciotomies.

Question 45

A patient experiences recurrent posterior dislocations following a total hip arthroplasty. Radiographic evaluation demonstrates an acetabular cup abduction angle of 40 degrees and anteversion of 0 degrees. What is the primary cause of the instability?

Explanation

The "safe zone" for acetabular component placement generally dictates an anteversion of 15 +/- 10 degrees. An anteversion of 0 degrees represents a lack of anteversion (retroversion), which strongly predisposes the patient to posterior hip dislocation.

Question 46

During a Part II oral exam, a candidate presents a case of an iatrogenic common peroneal nerve palsy following a surgical approach to the lateral tibia. According to ABOS evaluation rubrics, which candidate response demonstrates the highest level of professionalism and practice-based learning?

Explanation

In board examinations, examiners assess a candidate's ability to safely manage and honestly evaluate complications. Transparent documentation, early recognition, and executing an appropriate standard-of-care workup reflect maximum professionalism and patient safety.

Question 47

A 5-year-old child sustains a Gartland type III extension-type supracondylar humerus fracture. After successful closed reduction and percutaneous pinning, the hand remains pink but the radial pulse is absent on Doppler ultrasound. Capillary refill is 2 seconds. What is the most appropriate next step?

Explanation

A "pink, pulseless" hand following adequate reduction and stabilization of a pediatric supracondylar humerus fracture indicates sufficient collateral perfusion. The standard of care is close clinical observation, as vascular exploration is generally reserved for a "white, pulseless" hand.

Question 48

A 45-year-old patient has an incidental finding of a heavily calcified lesion in the proximal femur on an abdominal CT. Follow-up MRI and radiographs reveal endosteal scalloping involving >2/3 of the cortical thickness and soft tissue extension. The patient reports deep, aching thigh pain at night. What is the most likely diagnosis and appropriate treatment?

Explanation

Endosteal scalloping greater than 2/3 cortical thickness, soft tissue extension, and nocturnal pain in the setting of a cartilaginous lesion are hallmarks of high-grade chondrosarcoma. Wide resection is the treatment of choice, as these tumors are notoriously resistant to chemotherapy and radiation.

Question 49

A 22-year-old female presents with a purely ligamentous Lisfranc injury. Weight-bearing radiographs demonstrate 4 mm of diastasis between the bases of the 1st and 2nd metatarsals. According to high-level orthopedic evidence, which surgical intervention provides the most reliable long-term outcome?

Explanation

Level 1 evidence (e.g., Ly and Coetzee) has demonstrated that primary arthrodesis of the medial column (1st, 2nd, and 3rd TMT joints) yields better functional outcomes and fewer revision surgeries than ORIF for purely ligamentous Lisfranc injuries.

Question 50

In repairing a zone II flexor digitorum profundus (FDP) laceration, biomechanical studies demonstrate that the strength of the repair is most directly proportional to which of the following factors?

Explanation

The strength of a flexor tendon repair is most directly proportional to the number of core suture strands crossing the repair site. Modern protocols typically recommend at least 4 to 6 strands to safely permit early active motion rehabilitation.

Question 51

A 30-year-old male sustains a high-energy vertical femoral neck fracture (Pauwels Type III). What biomechanical challenge is most critical to overcome when selecting a fixation construct for this specific fracture pattern?

Explanation

Pauwels Type III femoral neck fractures have a vertically oriented fracture line (>50 degrees), which subjects the fracture site to high vertical shear forces rather than compression. Fixation constructs must be robust enough to resist these shear forces to prevent varus collapse and nonunion.

Question 52

A 65-year-old female presents with severe neurogenic claudication. Flexion-extension radiographs reveal an L4-L5 degenerative spondylolisthesis that increases from 3 mm of translation in extension to 8 mm in flexion. Based on standard guidelines for dynamic instability, what is the most appropriate surgical treatment?

Explanation

In the setting of symptomatic degenerative spondylolisthesis with clear dynamic instability (>3-4 mm of translation on dynamic views), decompression alone risks catastrophic postoperative destabilization. Decompression with instrumented fusion is the gold standard.

Question 53

A patient is 8 weeks post-operative from a primary total knee arthroplasty. Despite diligent physical therapy and good pain control, their active range of motion is 15 degrees of extension to 65 degrees of flexion. Radiographs show appropriately sized and positioned components without loosening. What is the most appropriate next step in management?

Explanation

For post-operative stiffness following TKA that fails to progress with physical therapy by 6-12 weeks, manipulation under anesthesia (MUA) is the most effective next step to break arthrofibrotic scar tissue before it fully matures.

Question 54

In the ABOS Part II structured oral examination, candidates are frequently asked to defend their surgical indications. If a candidate presents a complex intra-articular fracture that resulted in early hardware failure, what is the primary competency the examiner is assessing by probing the initial choice of fixation?

Explanation

The structured oral exam evaluates not just medical knowledge, but also practice-based learning. Examiners probe complications to see if the candidate can honestly self-reflect, identify technical or cognitive errors, and articulate how they would improve future practice.

Question 55

A 6-month-old female with developmental dysplasia of the hip (DDH) has failed a 4-week trial of a Pavlik harness for a dislocated left hip. Ultrasound confirms the hip remains dislocated. What is the most appropriate next step in management?

Explanation

If a Pavlik harness fails to achieve reduction within 3-4 weeks, it must be discontinued to avoid "Pavlik harness disease" (posterior acetabular wear and AVN). The next appropriate step is an examination under anesthesia, arthrogram, and closed reduction with spica casting.

Question 56

A 65-year-old female presents with recurrent posterior instability following a primary total hip arthroplasty. Radiographs demonstrate well-fixed components, with the acetabular cup at 45 degrees of inclination and 20 degrees of anteversion. The femoral head is 32mm. Examination reveals severely atrophied abductor musculature. What is the most appropriate surgical management?

Explanation

In cases of recurrent posterior instability with well-positioned, well-fixed components and deficient abductor musculature, a dual mobility construct provides increased jump distance and stability without altering cup position.

Question 57

A 35-year-old male involved in a high-speed MVC presents with a hemodynamically unstable APC-III pelvic ring injury. Following pelvic binder application and initial fluid resuscitation, his blood pressure remains 70/40 mmHg. The FAST exam is negative. What is the next best step in management?

Explanation

For a hemodynamically unstable pelvic fracture with a negative FAST exam (ruling out major intra-abdominal hemorrhage), preperitoneal pelvic packing and/or angiography with embolization is the appropriate emergent intervention.

Question 58

A 22-year-old football player is undergoing an ACL reconstruction using a bone-patellar tendon-bone autograft. During femoral tunnel drilling via the anteromedial portal, the posterior cortical wall blows out. What is the best intraoperative management?

Explanation

A posterior wall blowout compromises standard interference screw fixation. Suspensory cortical button fixation relies on the lateral femoral cortex, effectively bypassing the deficient posterior wall.

Question 59

A 68-year-old male presents with bilateral hand clumsiness, gait instability, and hyperreflexia. MRI demonstrates severe cervical stenosis with myelomalacia at C4-C5. He has neutral sagittal alignment and denies any neck pain. What is the most appropriate surgical approach?

Explanation

ACDF provides direct anterior decompression and stabilization for localized cervical spondylotic myelopathy. Laminectomy alone in a patient without lordosis carries a high risk of post-laminectomy kyphosis.

Question 60

A 13-year-old obese male presents with a sudden inability to bear weight on his right leg after a minor fall. Radiographs demonstrate a severe slipped capital femoral epiphysis (SCFE). Which of the following complications is he at the highest risk of developing compared to a patient who can bear weight?

Explanation

An unstable SCFE, defined clinically by the inability to bear weight, is associated with a significantly higher risk of avascular necrosis of the femoral head compared to a stable SCFE.

Question 61

A 15-year-old female presents with a blastic lesion and sunburst periosteal reaction in the distal femur. Biopsy confirms high-grade conventional osteosarcoma. Workup reveals no pulmonary metastases. What is the standard treatment protocol?

Explanation

The standard of care for high-grade conventional osteosarcoma is neoadjuvant chemotherapy, wide surgical resection, and adjuvant chemotherapy. This protocol has significantly improved long-term survival.

Question 62

A 55-year-old male with poorly controlled diabetes presents with a warm, swollen, erythematous left foot. His pedal pulses are bounding. Radiographs show fragmentation of the navicular and cuneiforms without any open ulcers. What is the most appropriate initial management?

Explanation

This presentation is classic for acute Eichenholtz stage I Charcot arthropathy. The gold standard initial treatment for an acute, non-ulcerated Charcot foot is strict offloading with a total contact cast to prevent progressive deformity.

Question 63

A 28-year-old male presents with radial-sided wrist pain 8 months after a fall. Radiographs demonstrate a scaphoid waist fracture nonunion with a "humpback" deformity. MRI confirms the proximal pole is well-vascularized. What is the recommended treatment?

Explanation

A scaphoid waist nonunion with a "humpback" deformity requires correction of the volar intercalated segment instability (VISI) posture. This is best achieved via a volar approach using an anterior wedge structural bone graft and rigid fixation.

Question 64

A 40-year-old female undergoes open reduction and internal fixation for a volar-shear distal radius fracture (Goyrand-Smith) using a standard volar Henry approach. Dissection straying too far ulnarly puts which of the following structures at greatest risk?

Explanation

The palmar cutaneous branch of the median nerve runs longitudinally between the FCR and palmaris longus. It is at high risk of iatrogenic injury during a standard volar Henry approach if the dissection retracts too far ulnarly.

Question 65

A 70-year-old male is 4 weeks post-operative from a total knee arthroplasty. He presents with acute onset knee pain, swelling, and erythema for 2 days. Aspiration yields 65,000 WBCs with 95% PMNs. Radiographs show well-fixed components. What is the best management?

Explanation

For an acute periprosthetic joint infection (symptoms lasting less than 3 weeks or occurring less than 4 weeks post-op) with well-fixed components, debridement, antibiotics, and implant retention (DAIR) with polyethylene liner exchange is the standard of care.

Question 66

A 6-year-old boy sustains a completely displaced extension-type supracondylar humerus fracture. Examination reveals a "puckered" appearance of the anterior antecubital skin and an absent radial pulse. The hand remains warm and pink. What is the next best step?

Explanation

A pink, pulseless hand in the setting of a displaced pediatric supracondylar humerus fracture is an indication for urgent closed reduction and percutaneous pinning. The pulse often returns immediately after anatomical fracture reduction.

Question 67

A 72-year-old female presents with severe neurogenic claudication that improves with leaning forward. MRI shows severe L4-L5 central stenosis with a mobile grade 1 degenerative spondylolisthesis. She has failed 6 months of conservative care. What is the preferred surgical intervention?

Explanation

Laminectomy combined with instrumented fusion is historically preferred for degenerative spondylolisthesis with stenosis, as it provides superior long-term clinical outcomes and prevents progressive instability compared to decompression alone.

Question 68

A 20-year-old collegiate rugby player has recurrent anterior shoulder instability. Three-dimensional CT reveals 28% glenoid bone loss. What is the most appropriate surgical intervention to minimize recurrence?

Explanation

In collision athletes with critical glenoid bone loss (>20-25%), isolated arthroscopic Bankart repairs have unacceptably high failure rates. A coracoid transfer (Latarjet) reconstructs the bone defect and provides a dynamic soft-tissue sling.

Question 69

A 42-year-old weekend warrior feels a "pop" in his posterior ankle while playing basketball. Examination reveals a palpable gap and a positive Thompson test. He opts for non-operative management. What is the optimal initial bracing protocol?

Explanation

Non-operative management of acute Achilles tendon ruptures utilizes functional bracing. Initial immobilization places the foot in resting equinus to appose the tendon ends, followed by sequential decreases in plantarflexion over several weeks.

Question 70

A 25-year-old male sustains a laceration over the volar aspect of his proximal phalanx (Zone II), severing both the FDS and FDP tendons. Following primary repair, what rehabilitation protocol yields the best outcomes?

Explanation

Early controlled motion protocols (e.g., early active extension/passive flexion or modified Duran) for Zone II flexor tendon repairs prevent restrictive adhesions while protecting the repair from excessive tension.

Question 71

A 28-year-old male suffers a closed tibial shaft fracture. Twelve hours later, he complains of severe leg pain out of proportion to the injury, worsening with passive toe stretch. During a dual-incision four-compartment fasciotomy, which compartment is most commonly missed?

Explanation

The deep posterior compartment is the most frequently missed or incompletely decompressed compartment during leg fasciotomies due to its deep anatomical location and proximity to the posterior neurovascular bundle.

Question 72

Which of the following fracture fixation constructs relies entirely on endochondral ossification (secondary bone healing) to achieve union?

Explanation

Intramedullary nails provide relative stability, allowing for controlled micromotion at the fracture site. This mechanical environment stimulates callus formation, leading to secondary bone healing via endochondral ossification.

Question 73

A 60-year-old female presents with deep thigh pain. Radiographs show a lytic lesion with "popcorn" calcifications in the proximal femur metaphysis. Biopsy confirms a low-grade (Grade 1) chondrosarcoma. What is the most appropriate surgical treatment?

Explanation

Low-grade (Grade 1) chondrosarcomas of the long bones can safely and effectively be managed with joint-sparing extensive intralesional curettage, local chemical/thermal adjuvants, and cementation.

Question 74

A 55-year-old male with a history of a metal-on-metal THA 10 years ago presents with groin pain and a palpable mass. Serum cobalt and chromium levels are highly elevated. MRI demonstrates a large pseudotumor. What is the next best step?

Explanation

Adverse local tissue reactions (ALTR) or pseudotumors associated with elevated metal ions in metal-on-metal THA indicate progressive soft tissue destruction, requiring revision to a non-MoM bearing surface.

Question 75

A 32-year-old male sustains a Pauwels type III femoral neck fracture. He undergoes closed reduction and percutaneous pinning with three cannulated screws. At 6-month follow-up, radiographs show varus collapse and 1.5 cm of shortening, but no evidence of avascular necrosis on MRI. He reports moderate groin pain with weight-bearing. What is the most appropriate next step in management?

Explanation

Valgus intertrochanteric osteotomy alters the mechanical axis, converting shear forces to compressive forces at the fracture site. It is the treatment of choice for young patients with femoral neck nonunion or varus collapse who have preserved femoral head viability.

Question 76

A 65-year-old male presents with worsening hand clumsiness, a positive Hoffman's sign, and lower extremity hyperreflexia. MRI shows severe cervical stenosis at C4-C6 with cord signal changes. He undergoes a C4-C6 anterior cervical discectomy and fusion (ACDF). Postoperatively, he exhibits isolated new-onset right deltoid and biceps weakness without sensory deficits. What is the most likely etiology of this new neurological deficit?

Explanation

C5 nerve root palsy is a known complication following cervical decompression, typically presenting as isolated deltoid and/or biceps weakness. It is thought to occur due to the posterior shift of the spinal cord resulting in traction on the relatively tethered C5 nerve root.

Question 77

A 10-year-old female soccer player with wide-open physes sustains a complete mid-substance anterior cruciate ligament (ACL) tear. Operative intervention is planned due to persistent, symptomatic instability. Which of the following surgical techniques minimizes the risk of iatrogenic growth arrest?

Explanation

In skeletally immature patients with significant remaining growth (Tanner stages 1 and 2), an all-epiphyseal or physeal-sparing ACL reconstruction is recommended to prevent physeal injury. Hamstring autografts are typically utilized to avoid placing a bone block across or near the open physis.

Question 78

A 28-year-old laborer presents with chronic radial-sided wrist pain 18 months after a fall. Radiographs demonstrate a scaphoid waist nonunion with a humpback deformity, dorsal intercalated segment instability (DISI), and established radiocarpal arthrosis. Which of the following is the most appropriate surgical management?

Explanation

Scaphoid excision and four-corner fusion is indicated for scaphoid nonunion advanced collapse (SNAC) with established radiocarpal arthrosis. Bone grafting to achieve union is contraindicated once significant degenerative changes have developed in the midcarpal or radiocarpal joints.

Question 79

A 72-year-old female presents with persistent left knee pain, swelling, and a draining sinus tract that developed two months ago, three years following a primary total knee arthroplasty (TKA). Aspiration yields 65,000 WBCs/mcL (92% PMNs), and cultures grow methicillin-resistant Staphylococcus aureus (MRSA). Radiographs show well-fixed components. What is the most appropriate surgical management?

Explanation

For a chronic periprosthetic joint infection (symptoms > 4 weeks or presence of a sinus tract), especially with highly virulent organisms like MRSA, a two-stage revision TKA is the gold standard in the United States. Irrigation and debridement with liner exchange is reserved for acute infections (< 3 weeks) with susceptible organisms.

Question 80

A 13-year-old obese boy undergoes in situ percutaneous single-screw fixation for a stable slipped capital femoral epiphysis (SCFE). Which of the following represents the most significant long-term clinical complication directly associated with the residual deformity from this condition?

Explanation

Even after successful in situ fixation of a SCFE, the residual proximal femoral deformity (a prominent anterolateral metaphysis) frequently leads to cam-type femoroacetabular impingement (FAI). Over time, this impingement causes labral tearing and early secondary hip osteoarthritis.

Question 81

A 15-year-old male presents with a mixed lytic and blastic lesion in the distal femoral metaphysis with periosteal reaction forming a Codman's triangle. Biopsy demonstrates malignant spindle cells producing osteoid matrix, confirming osteosarcoma. What is the most critical prognostic factor for this patient's long-term overall survival?

Explanation

The degree of tumor necrosis following neoadjuvant chemotherapy is the most important prognostic factor for overall survival in patients with high-grade, non-metastatic osteosarcoma. Greater than 90% necrosis is classified as a good histologic response and strongly correlates with improved outcomes.

Question 82

A 55-year-old male with poorly controlled diabetes presents with a swollen, erythematous, and warm right foot without open ulceration. Radiographs show acute fragmentation, periarticular debris, and subluxation at the tarsometatarsal joints. Inflammatory markers are mildly elevated. What is the most appropriate initial management?

Explanation

The patient is in the acute, inflammatory phase (Eichenholtz stage I) of Charcot arthropathy. The gold standard for initial management is total contact casting and strict non-weight-bearing to arrest the inflammatory process and prevent progressive midfoot collapse.

Question 83

A 68-year-old male with a massive, retracted, irreparable posterosuperior rotator cuff tear presents with pseudoparalysis of the right shoulder. Radiographs show advanced Hamada grade 4 cuff tear arthropathy. His axillary nerve and deltoid function are intact. What is the most appropriate definitive surgical intervention?

Explanation

Reverse total shoulder arthroplasty (RTSA) is the treatment of choice for elderly patients with massive, irreparable rotator cuff tears, pseudoparalysis, and established cuff tear arthropathy. By medializing and distalizing the center of rotation, RTSA allows the intact deltoid muscle to effectively elevate the arm.

Question 84

During an ABOS oral examination, an examiner asks the candidate about the biomaterial science behind bearing surfaces in total hip arthroplasty. Which of the following factors most significantly contributes to the phenomenon of "stripe wear" in ceramic-on-ceramic articulations?

Explanation

Stripe wear in ceramic-on-ceramic bearings is primarily caused by microseparation of the femoral head from the acetabular liner during the swing phase, followed by edge loading upon heel strike. This repetitive edge loading results in a characteristic linear wear track on the ceramic head.

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

ABOS Part I & II Oral Exam Comprehensive Orthopedic Review MCQs | Part 22306

Key Takeaway

ABOS Part I & II Oral Exam Comprehensive Orthopedic Review MCQs | Part 22306

Correct Answer: C

Correct Answer: C

Correct Answer: B

Correct Answer: C

Correct Answer: C

Correct Answer: C

Correct Answer: C

Correct Answer: B

Correct Answer: D

Correct Answer: C

Chapter Index