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1. General Principles & Basic Science MCQs

Practice Set 101 of 789

This practice set contains high-yield board review questions covering key concepts in 1. General Principles & Basic Science. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 2001

Topic: 1. General Principles & Basic Science

A 72-year-old female presents with bilateral knee pain and gradual deformity. Weightbearing anteroposterior radiographs are obtained, as shown below. Based on the provided image and case description, which of the following best describes the primary radiographic findings and the associated arthritic pattern?

. Option A: Medial compartment bone-on-bone contact with varus deformity, consistent with primary osteoarthritis.
. Option B: Patellofemoral arthrosis with lateral subluxation, indicating isolated patellofemoral syndrome.
. Option C: Lateral compartment bone-on-bone contact with moderate valgus deformity, and early medial compartment arthrosis.
. Option D: Diffuse joint space narrowing with significant osteophyte formation, suggestive of inflammatory arthritis.
. Option E: Isolated lateral meniscal extrusion with preserved joint space, indicating a meniscal tear without significant arthritis.

Correct Answer & Explanation

. Option C: Lateral compartment bone-on-bone contact with moderate valgus deformity, and early medial compartment arthrosis.

Explanation

Correct Answer: CThe case explicitly states, and the image demonstrates, 'narrowing of joint spaces with bone-on-bone contact in the lateral compartments of both knees. There is early arthrosis affecting the medial compartments of both knees. There is moderate valgus deformity.' This directly matches option C.Option A is incorrectbecause the deformity is valgus, not varus, and the primary bone-on-bone contact is in the lateral compartment, not medial.Option B is incorrectas the primary finding is tibiofemoral arthritis with valgus deformity, not isolated patellofemoral arthrosis.Option D is incorrectbecause while arthritis is present, the description specifies lateral compartment bone-on-bone contact and early medial arthrosis, not diffuse narrowing as the primary descriptor, and the image does not strongly suggest diffuse inflammatory changes over a specific compartment pattern.Option E is incorrectbecause the radiographs clearly show significant arthritic changes with bone-on-bone contact, not preserved joint space, and the primary diagnosis is arthritis with deformity, not an isolated meniscal tear.

Question 2002

Topic: 1. General Principles & Basic Science

A 68-year-old female presents with a valgus knee deformity and symptomatic arthritis, similar to the patient in the case. During the preoperative workup, the surgeon considers potential etiologies for this pattern of joint disease. Which of the following conditions is LEAST commonly associated with a valgus deformity of the knee with arthritis?

. Option A: Rheumatoid arthritis
. Option B: Primary osteoarthritis
. Option C: Overcorrection of a high tibial osteotomy (HTO)
. Option D: Post-traumatic arthritis following medial meniscectomy
. Option E: Osteonecrosis of the lateral femoral condyle

Correct Answer & Explanation

. Option D: Post-traumatic arthritis following medial meniscectomy

Explanation

Correct Answer: DThe case specifically lists conditions commonly associated with valgus deformity of the knee with arthritis: 'inflammatory joint conditions such as rheumatoid arthritis... primary osteoarthritis, overcorrection of high tibial osteotomy (HTO), post-traumatic arthritis following lateral meniscectomy and osteonecrosis.' Post-traumatic arthritis following amedialmeniscectomy would typically predispose tovarusdeformity and medial compartment arthritis, not valgus deformity.Option A (Rheumatoid arthritis) is incorrectbecause the case explicitly states it is a common association.Option B (Primary osteoarthritis) is incorrectbecause the case explicitly states it can occur in primary osteoarthritis.Option C (Overcorrection of a high tibial osteotomy (HTO)) is incorrectbecause the case explicitly states it can occur due to HTO overcorrection.Option E (Osteonecrosis of the lateral femoral condyle) is incorrectbecause the case explicitly states it can be a cause of valgus arthritis.

Question 2003

Topic: 1. General Principles & Basic Science

A surgeon is performing a TKR on a patient with a severe valgus deformity. During soft tissue balancing, significant release of the lateral and posterior structures is required to achieve adequate correction. What is the most likely immediate consequence of this extensive soft tissue release on the flexion-extension gap, and how might it impact implant selection?

. Option A: Decreased extension gap, requiring a thinner polyethylene insert and potentially a smaller femoral component.
. Option B: Increased extension gap, requiring a thicker polyethylene insert and potentially elevating the joint line.
. Option C: Balanced flexion and extension gaps, allowing for a standard polyethylene insert and preserving the joint line.
. Option D: Increased flexion gap, necessitating a larger femoral component to fill the space.
. Option E: Decreased flexion gap, requiring a posterior-stabilized implant to compensate for tightness.

Correct Answer & Explanation

. Option B: Increased extension gap, requiring a thicker polyethylene insert and potentially elevating the joint line.

Explanation

Correct Answer: BThe case states: 'With regards to flexion–extension gap, the release of lateral and posterior structures results in increased extension gap requiring a thicker insert which may elevate the joint line.' This directly describes the consequence of extensive lateral and posterior soft tissue release in a valgus knee.Option A is incorrectbecause releasing contracted structures would increase, not decrease, the extension gap.Option C is incorrectbecause significant release of contracted structures will almost certainly alter the gap, making it unlikely to be perfectly balanced without specific intervention.Option D is incorrectbecause the primary effect of releasing lateral and posterior structures is on the extension gap, not typically an isolated increase in the flexion gap that would necessitate a larger femoral component.Option E is incorrectbecause releasing structures would loosen, not tighten, the knee, making a decreased flexion gap unlikely.

Question 2004

Topic: 1. General Principles & Basic Science

In a patient presenting with a valgus knee deformity requiring TKR, the case describes specific anatomical and rotational characteristics of the femur and tibia. Which of the following statements accurately describes these characteristic deformities?

. Option A: The medial femoral condyle is deficient, the femur is externally rotated, and the tibia is internally rotated.
. Option B: The lateral femoral condyle is deficient, the femur is internally rotated, and the tibia is externally rotated.
. Option C: Both femoral condyles are equally deficient, and both the femur and tibia are externally rotated.
. Option D: The lateral femoral condyle is hypertrophied, the femur is externally rotated, and the tibia is internally rotated.
. Option E: The medial femoral condyle is deficient, the femur is internally rotated, and the tibia is internally rotated.

Correct Answer & Explanation

. Option B: The lateral femoral condyle is deficient, the femur is internally rotated, and the tibia is externally rotated.

Explanation

Correct Answer: BThe case explicitly states: 'In valgus knees the lateral femoral condyle is deficient, therefore the femur is internally rotated and tibia is externally rotated.' This directly matches option B.Option A is incorrectbecause the lateral femoral condyle is deficient, not the medial, and the rotational deformities are reversed.Option C is incorrectbecause the lateral femoral condyle is specifically deficient, not both equally, and the rotational deformities are not both external.Option D is incorrectbecause the lateral femoral condyle is deficient, not hypertrophied, and the rotational deformities are reversed.Option E is incorrectbecause the lateral femoral condyle is deficient, not the medial, and the tibial rotation is external, not internal.

Question 2005

Topic: Surgical Anatomy & Approaches
A surgeon is planning a TKR for a patient with a valgus knee. While a medial parapatellar approach is commonly used, the surgeon considers a lateral approach. According to the case, what is the theoretical advantage of utilizing a lateral surgical approach for total knee arthroplasty in a valgus knee?
. It provides better access to the medial compartment for soft tissue release.
. It offers superior soft tissue coverage for the extensor mechanism.
. It is a direct approach providing easier access and preserves the neurovascular supply to the extensor mechanism.
. It allows for easier correction of internal rotation of the femoral component.
. It reduces the risk of peroneal nerve palsy postoperatively.

Correct Answer & Explanation

. It is a direct approach providing easier access and preserves the neurovascular supply to the extensor mechanism.

Explanation

The case directly addresses this: 'EXAMINER: What is the theoretical advantage of a lateral approach? CANDIDATE: It is a direct approach providing easier access and preserves the neurovascular supply to the extensor mechanism.' This statement directly supports option C. Option A is incorrect because a lateral approach would make medial compartment access more challenging, not easier. Option B is incorrect because the case states that a medial parapatellar approach 'gives good access to the whole knee and better soft tissue cover,' implying this is an advantage of the medial approach, not the lateral. Option D is incorrect because while component rotation is critical, the advantage of the lateral approach is not specifically tied to easier correction of femoral internal rotation compared to other approaches. Option E is incorrect because the risk of peroneal nerve palsy is related to the degree of valgus correction and traction on the nerve, not inherently reduced by the surgical approach itself.

Question 2006

Topic: Infection, Pharmacology & VTE

When discussing consent for the proposed Scarf osteotomy, the candidate outlines potential complications.

Which of the following complications is explicitly mentioned by the candidate as a possibility following a Scarf osteotomy?

. Deep vein thrombosis (DVT) and pulmonary embolism (PE).
. A high risk of avascular necrosis of the metatarsal head.
. Significant stiffness of the MTP joint and sensory loss due to dorsomedial sensory nerve injury.
. Chronic regional pain syndrome (CRPS) as a common sequela.
. A 50% chance of recurrence within 5 years.

Correct Answer & Explanation

. Significant stiffness of the MTP joint and sensory loss due to dorsomedial sensory nerve injury.

Explanation

Correct Answer: CThe candidate explicitly states: 'A minority of patients will have significant stiffness of the MTP joint afterwards and there can be sensory loss if the dorsomedial sensory nerve is injured.' While DVT/PE and CRPS are general surgical risks, they are not specifically highlighted by the candidate in this discussion. Avascular necrosis is a known complication of some distal osteotomies (e.g., Chevron) but not specifically emphasized for Scarf in this context. The recurrence risk is mentioned as 'greatest in adolescent cases' and not given a specific high percentage like 50% for this patient.

Question 2007

Topic: Infection, Pharmacology & VTE
According to the AAOS Clinical Practice Guidelines on the management of osteoarthritis of the knee, which of the following non-operative modalities has a strong recommendation against its use?
. Oral nonsteroidal anti-inflammatory drugs (NSAIDs)
. Supervised physical therapy
. Intra-articular hyaluronic acid (viscosupplementation) injections
. Weight loss for patients with a BMI > 25
. Intra-articular corticosteroid injections

Correct Answer & Explanation

. Intra-articular hyaluronic acid (viscosupplementation) injections

Explanation

The AAOS guidelines provide a strong recommendation against the use of intra-articular hyaluronic acid for symptomatic knee osteoarthritis, citing a lack of clinically significant efficacy over placebo. NSAIDs, weight loss, and physical therapy all have strong recommendations for use.

Question 2008

Topic: 1. General Principles & Basic Science

When performing a medial opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis, failing to account for the native triangular geometry of the proximal tibia (wider anteriorly than posteriorly) during the opening will most likely result in which unintended intraoperative change?

. Decreased posterior tibial slope
. Increased posterior tibial slope
. Increased patellar height (patella alta)
. Iatrogenic valgus overcorrection
. Sagittal plane extension deformity

Correct Answer & Explanation

. Increased posterior tibial slope

Explanation

Opening the anterior and posterior cortex equally during a medial opening wedge HTO will unintentionally increase the posterior tibial slope because the anterior tibial dimension is naturally larger. The anterior gap must generally be roughly half the size of the posterior gap to maintain the native slope.

Question 2009

Topic: 1. General Principles & Basic Science

A 52-year-old male is diagnosed with moderate midfoot (tarsometatarsal) osteoarthritis. He wishes to pursue non-operative management. Which of the following footwear modifications is most appropriate to alleviate his symptoms?

. A flexible, minimalist running shoe
. A shoe with an elevated heel and wide toe box
. A stiff-soled shoe with a full-length steel shank and a rocker bottom
. A shoe insert with a medial heel wedge
. A shoe insert with a lateral forefoot post

Correct Answer & Explanation

. A stiff-soled shoe with a full-length steel shank and a rocker bottom

Explanation

Midfoot arthritis pain occurs primarily during the propulsive phase of gait when bending moments across the tarsometatarsal joints are maximal. A stiff-soled shoe with a full-length steel shank and a rocker bottom limits midfoot dorsiflexion and effectively unloads the arthritic joints.

Question 2010

Topic: Infection, Pharmacology & VTE

According to the American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guidelines for the management of osteoarthritis of the knee, which of the following non-operative treatments is strongly recommended based on high-quality evidence?

. Intra-articular hyaluronic acid injections
. Oral glucosamine and chondroitin sulfate supplementation
. Lateral wedge insoles for medial compartment osteoarthritis
. Weight loss and oral nonsteroidal anti-inflammatory drugs (NSAIDs)
. Arthroscopic lavage and debridement

Correct Answer & Explanation

. Weight loss and oral nonsteroidal anti-inflammatory drugs (NSAIDs)

Explanation

The AAOS strongly recommends weight loss, physical therapy, and oral NSAIDs for the symptomatic treatment of knee osteoarthritis. High-quality evidence has consistently demonstrated a lack of efficacy for oral glucosamine/chondroitin, lateral wedge insoles, and intra-articular hyaluronic acid in the routine management of primary knee OA.

Question 2011

Topic: 1. General Principles & Basic Science

A 60-year-old female presents with progressive, activity-related aching in the midfoot. Radiographs reveal isolated osteoarthritis of the tarsometatarsal joints. She strongly prefers non-operative management. What specific shoe modification is most appropriate to alleviate her symptoms?

. Flexible, minimalist running shoe
. High-heeled shoe with a narrow toe box
. Stiff-soled shoe with a rocker bottom
. Shoe with a medial heel wedge
. Shoe with a lateral heel wedge

Correct Answer & Explanation

. Stiff-soled shoe with a rocker bottom

Explanation

A stiff-soled shoe with a rocker bottom effectively limits stress and motion through the arthritic midfoot joints during the toe-off phase of gait. This modification is highly successful for the conservative management of midfoot arthritis.

Question 2012

Topic: Surgical Anatomy & Approaches

A 32-year-old male sustains a high-energy motor vehicle collision resulting in a displaced anterior column acetabular fracture. During open reduction and internal fixation via the Smith-Petersen approach, the surgeon identifies the primary internervous plane. Which two muscles define this critical interval, and what are their respective innervations?

. A. Gluteus medius (superior gluteal nerve) and rectus femoris (femoral nerve)
. B. Sartorius (femoral nerve) and rectus femoris (femoral nerve)
. C. Sartorius (femoral nerve) and tensor fascia lata (superior gluteal nerve)
. D. Tensor fascia lata (superior gluteal nerve) and vastus lateralis (femoral nerve)
. E. Iliopsoas (femoral nerve) and pectineus (femoral nerve)
. F. Gluteus minimus (superior gluteal nerve) and sartorius (femoral nerve)

Correct Answer & Explanation

. C. Sartorius (femoral nerve) and tensor fascia lata (superior gluteal nerve)

Explanation

Correct Answer: CThe Smith-Petersen approach primarily utilizes an internervous plane proximally between the sartorius muscle and the tensor fascia lata (TFL) muscle. The sartorius muscle is innervated by the femoral nerve (L2-L4), and the TFL muscle is innervated by the superior gluteal nerve (L4-S1). This distinct innervation pattern allows for dissection without denervating either muscle, theoretically minimizing muscle damage and facilitating recovery.Why other options are incorrect:A. Gluteus medius (superior gluteal nerve) and rectus femoris (femoral nerve):While these muscles are in the vicinity, the gluteus medius is lateral to the primary interval and the rectus femoris is deep to it, requiring reflection. This is not the primary internervous plane.B. Sartorius (femoral nerve) and rectus femoris (femoral nerve):Both muscles are innervated by the femoral nerve, making this an intramuscular plane, not an internervous one. The rectus femoris is also deep to the sartorius, not adjacent in the primary interval.D. Tensor fascia lata (superior gluteal nerve) and vastus lateralis (femoral nerve):The vastus lateralis is a component of the quadriceps femoris, located more distally and deep to the TFL. This is not the primary internervous plane for initial hip joint access.E. Iliopsoas (femoral nerve) and pectineus (femoral nerve):Both are medial to the primary approach and innervated by the femoral nerve. The iliopsoas lies posteromedial to the rectus femoris and inferior to the anterior hip joint, requiring careful medial retraction if needed for deeper exposure, but it does not define the primary internervous plane.F. Gluteus minimus (superior gluteal nerve) and sartorius (femoral nerve):The gluteus minimus is deep to the gluteus medius and lateral to the primary interval. It is not directly involved in defining the primary internervous plane of the Smith-Petersen approach.

Question 2013

Topic: Surgical Anatomy & Approaches

A 58-year-old female undergoes a revision total hip arthroplasty via the Smith-Petersen approach for a loose acetabular component. Two weeks post-operatively, she complains of persistent numbness, burning, and dysesthesia over the anterolateral aspect of her operative thigh. Physical examination confirms sensory deficits in this distribution without motor weakness. Which of the following nerves is most likely injured, and what is its typical anatomical course relative to the ASIS?

. A. Femoral nerve; exits the pelvis medial to the ASIS and courses inferomedially.
. B. Sciatic nerve; exits the pelvis through the greater sciatic notch, posterior to the hip joint.
. C. Obturator nerve; exits the pelvis through the obturator foramen, medial to the hip joint.
. D. Lateral femoral cutaneous nerve; exits the pelvis typically inferior to the ASIS and courses inferomedially, often piercing or passing deep to the sartorius or TFL.
. E. Superior gluteal nerve; exits the pelvis through the greater sciatic notch, superior to the piriformis muscle.

Correct Answer & Explanation

. D. Lateral femoral cutaneous nerve; exits the pelvis typically inferior to the ASIS and courses inferomedially, often piercing or passing deep to the sartorius or TFL.

Explanation

Correct Answer: DThe patient's symptoms of numbness, burning, and dysesthesia over the anterolateral thigh are classic for meralgia paresthetica, which is caused by injury to the lateral femoral cutaneous nerve (LFCN). The LFCN is a purely sensory nerve (L2-L3) that exits the pelvis, typically inferior to the ASIS, and courses inferomedially. Its course is highly variable, often piercing or passing deep to the sartorius or tensor fascia lata (TFL), making it particularly vulnerable during the Smith-Petersen approach. It is the most common neurological complication of this approach.Why other options are incorrect:A. Femoral nerve; exits the pelvis medial to the ASIS and courses inferomedially:While the femoral nerve is medial to the sartorius and vulnerable to medial retraction, its injury would typically result in quadriceps weakness (motor deficit) and sensory loss on the anterior thigh and medial leg, not specifically the anterolateral thigh dysesthesia.B. Sciatic nerve; exits the pelvis through the greater sciatic notch, posterior to the hip joint:The sciatic nerve is located posteriorly and is not typically at risk during an anterior approach like Smith-Petersen. Injury would cause motor and sensory deficits in the posterior thigh and entire lower leg/foot.C. Obturator nerve; exits the pelvis through the obturator foramen, medial to the hip joint:The obturator nerve supplies the adductor muscles and sensation to the medial thigh. It is not typically at risk with the Smith-Petersen approach and its injury would present with adductor weakness and medial thigh sensory changes.E. Superior gluteal nerve; exits the pelvis through the greater sciatic notch, superior to the piriformis muscle:The superior gluteal nerve supplies the gluteus medius, minimus, and TFL. It is located superior and lateral to the primary approach and is generally not directly at risk unless dissection extends significantly superiorly and laterally along the iliac crest. Injury would cause abductor weakness (Trendelenburg gait).

Question 2014

Topic: Surgical Anatomy & Approaches

During the deep dissection phase of a Smith-Petersen approach for an anterior column acetabular fracture, after detaching the direct and indirect heads of the rectus femoris and reflecting the muscle distally and laterally, the surgical team encounters a pulsatile bleed deep to the reflected rectus femoris. Which vessel is most likely the source of this bleeding?

. A. Femoral artery
. B. Superior gluteal artery
. C. Ascending branch of the lateral circumflex femoral artery
. D. Obturator artery
. E. Deep femoral artery (profunda femoris)

Correct Answer & Explanation

. C. Ascending branch of the lateral circumflex femoral artery

Explanation

Correct Answer: CAs the rectus femoris muscle is reflected distally and laterally during the deep dissection of the Smith-Petersen approach, the ascending branch of the lateral circumflex femoral artery is almost always encountered. This vessel, a branch of the deep femoral artery (profunda femoris), runs deep to the rectus femoris and supplies the vastus lateralis and contributes to the vascular supply of the femoral head. It must be carefully identified and ligated or cauterized to prevent hemorrhage. Its ligation is generally well-tolerated due to redundant blood supply.Why other options are incorrect:A. Femoral artery:The femoral artery is located more medially within the femoral triangle, medial to the femoral nerve and iliopsoas. While at risk with aggressive medial retraction, it is not typically encountered deep to the rectus femoris during its reflection.B. Superior gluteal artery:The superior gluteal artery is located more superiorly and laterally, exiting the pelvis through the greater sciatic notch. It supplies the gluteal muscles and TFL and is generally not directly at risk during the standard Smith-Petersen approach unless dissection extends significantly superiorly and laterally along the iliac crest.D. Obturator artery:The obturator artery is located medially within the pelvis, supplying structures in the obturator region. It is not typically encountered in the field of view during rectus femoris reflection in a Smith-Petersen approach.E. Deep femoral artery (profunda femoris):While the ascending branch of the lateral circumflex femoral artery originates from the deep femoral artery, the main trunk of the deep femoral artery is located more medially and deeper in the thigh, not typically exposed directly during rectus femoris reflection.

Question 2015

Topic: Surgical Anatomy & Approaches

A surgical resident is preparing a patient for a Smith-Petersen approach to address developmental dysplasia of the hip (DDH) requiring a pelvic osteotomy. The patient is positioned supine on a radiolucent operating table. To optimize exposure of the anterior acetabulum and iliac wing, a firm bolster is placed under the ipsilateral gluteal region. What is the primary biomechanical effect of this bolster placement?

. A. To facilitate hip extension and external rotation.
. B. To internally rotate the pelvis, bringing the ASIS and iliac crest more anteriorly.
. C. To externally rotate the pelvis, moving the ASIS laterally.
. D. To increase lumbar lordosis, improving access to the posterior pelvis.
. E. To abduct the hip, tensioning the gluteal muscles.

Correct Answer & Explanation

. B. To internally rotate the pelvis, bringing the ASIS and iliac crest more anteriorly.

Explanation

Correct Answer: BPlacing a firm bolster or rolled towel under the ipsilateral gluteal region (from the sacrum to the greater trochanter) internally rotates the pelvis. This maneuver brings the Anterior Superior Iliac Spine (ASIS) and the iliac crest more anteriorly, which significantly facilitates access to the anterior acetabulum and iliac wing, crucial for the Smith-Petersen approach. This positioning optimizes the surgical field for the anterior approach.Why other options are incorrect:A. To facilitate hip extension and external rotation:This positioning would typically be achieved by placing a bolster under the contralateral hip or by specific leg manipulation, but not primarily by an ipsilateral gluteal bolster for anterior exposure.C. To externally rotate the pelvis, moving the ASIS laterally:This is the opposite effect of the ipsilateral gluteal bolster, which aims to internally rotate the pelvis.D. To increase lumbar lordosis, improving access to the posterior pelvis:A bolster under the gluteal region does not primarily aim to increase lumbar lordosis, and the Smith-Petersen approach is for anterior, not posterior, pelvic access.E. To abduct the hip, tensioning the gluteal muscles:While leg draping allows for hip manipulation, the primary purpose of the ipsilateral gluteal bolster is not to abduct the hip or tension the gluteal muscles.

Question 2016

Topic: Surgical Anatomy & Approaches

A 40-year-old male is undergoing a Smith-Petersen approach for open reduction and internal fixation of a complex anterior column acetabular fracture. During deep dissection, the surgeon requires extensive medial exposure to access the pubic ramus and quadrilateral surface. The iliopsoas muscle is retracted medially. What critical neurovascular structure is immediately medial to the iliopsoas and at significant risk with aggressive or prolonged retraction in this area?

. A. Sciatic nerve
. B. Superior gluteal nerve and artery
. C. Lateral femoral cutaneous nerve
. D. Femoral nerve and vessels
. E. Obturator nerve

Correct Answer & Explanation

. D. Femoral nerve and vessels

Explanation

Correct Answer: DThe text explicitly states: 'Care must be taken as the femoral nerve and vessels lie directly medial to the iliopsoas.' When the iliopsoas muscle is retracted medially for extensive medial exposure (e.g., to access the pubic ramus or quadrilateral surface for acetabular fractures), the femoral nerve and vessels (artery and vein) are immediately adjacent and highly vulnerable to direct trauma or excessive/prolonged retraction. Injury to the femoral nerve can lead to significant quadriceps weakness and sensory deficits.Why other options are incorrect:A. Sciatic nerve:The sciatic nerve is located posteriorly and is not at risk during medial retraction of the iliopsoas in an anterior approach.B. Superior gluteal nerve and artery:These structures are located more superior and lateral, supplying the gluteus medius, minimus, and TFL. They are not immediately medial to the iliopsoas.C. Lateral femoral cutaneous nerve:While the LFCN is vulnerable in the Smith-Petersen approach, it typically exits inferior to the ASIS and courses inferomedially, often piercing the sartorius or TFL. It is not immediately medial to the iliopsoas in the deep dissection plane.E. Obturator nerve:The obturator nerve is located more medially within the pelvis, exiting through the obturator foramen. While it is a pelvic nerve, it is not immediately adjacent to the iliopsoas in the context of medial retraction during the Smith-Petersen approach.

Question 2017

Topic: Surgical Anatomy & Approaches

A 65-year-old patient is undergoing a primary total hip arthroplasty via a modified Smith-Petersen (direct anterior) approach. During exposure of the hip capsule, the surgeon notes a strong, inverted Y-shaped ligament reinforcing the anterior aspect of the capsule, extending from the anterior inferior iliac spine (AIIS) to the intertrochanteric line. What is the name of this ligament, and what is its primary biomechanical function?

. A. Pubofemoral ligament; prevents excessive abduction.
. B. Ischiofemoral ligament; prevents excessive internal rotation.
. C. Ligamentum teres; provides vascular supply to the femoral head.
. D. Iliofemoral ligament (Ligament of Bigelow); prevents hyperextension.
. E. Transverse acetabular ligament; deepens the acetabular socket.

Correct Answer & Explanation

. D. Iliofemoral ligament (Ligament of Bigelow); prevents hyperextension.

Explanation

Correct Answer: DThe description of a strong, inverted Y-shaped ligament extending from the AIIS to the intertrochanteric line is characteristic of the iliofemoral ligament, also known as the Ligament of Bigelow. This is recognized as the strongest ligament of the hip joint, and its primary biomechanical function is to prevent hyperextension of the hip, contributing significantly to anterior hip stability.Why other options are incorrect:A. Pubofemoral ligament; prevents excessive abduction:The pubofemoral ligament is located inferiorly and anteriorly, and while it contributes to hip stability, its primary role is to prevent excessive abduction and external rotation, not hyperextension, and it does not have the described Y-shape.B. Ischiofemoral ligament; prevents excessive internal rotation:The ischiofemoral ligament is located posteriorly and primarily prevents excessive internal rotation and hyperextension, but it is not the strongest anterior ligament and is not encountered in the anterior approach in the same manner.C. Ligamentum teres; provides vascular supply to the femoral head:The ligamentum teres is an intra-articular ligament connecting the fovea of the femoral head to the acetabular notch. While it can provide some vascular supply (artery to the head of the femur), it is not a primary stabilizer of the hip joint and does not have the described shape or location.E. Transverse acetabular ligament; deepens the acetabular socket:The transverse acetabular ligament bridges the acetabular notch, converting it into a foramen. Its function is to deepen the acetabular socket and provide a passage for neurovascular structures, but it is not the primary anterior capsular ligament.

Question 2018

Topic: 1. General Principles & Basic Science

A 35-year-old male undergoes open reduction and internal fixation of a complex acetabular fracture via the Smith-Petersen approach. He has a history of ankylosing spondylitis and a previous episode of heterotopic ossification (HO) following a shoulder fracture. To mitigate the risk of HO, the surgeon plans post-operative prophylaxis. Which of the following is the most appropriate and evidence-based prophylactic regimen for this high-risk patient?

. A. High-dose corticosteroids for 6 weeks.
. B. Daily oral calcium and vitamin D supplementation.
. C. A single dose of post-operative radiation therapy (PORT) within 72 hours of surgery.
. D. Long-term therapeutic anticoagulation with warfarin.
. E. Continuous passive motion (CPM) for 24 hours post-operatively.

Correct Answer & Explanation

. C. A single dose of post-operative radiation therapy (PORT) within 72 hours of surgery.

Explanation

Correct Answer: CFor high-risk patients, such as those with a history of ankylosing spondylitis and previous HO, a single dose of post-operative radiation therapy (PORT, 7-10 Gy) administered within 72 hours of surgery is an equally effective and well-established prophylactic measure against heterotopic ossification as NSAIDs. It is particularly useful in patients with contraindications to NSAIDs or those at very high risk. The text specifically mentions this as an option for HO prophylaxis.Why other options are incorrect:A. High-dose corticosteroids for 6 weeks:Corticosteroids are not a standard or evidence-based prophylaxis for HO and carry significant side effects, including impaired wound healing and increased infection risk.B. Daily oral calcium and vitamin D supplementation:These are important for bone health but do not prevent heterotopic ossification.D. Long-term therapeutic anticoagulation with warfarin:Warfarin is used for DVT/PE prophylaxis or treatment, not for HO prophylaxis.E. Continuous passive motion (CPM) for 24 hours post-operatively:While CPM can be used in some orthopedic rehabilitation protocols, it is not an established or effective method for preventing HO. The primary methods are NSAIDs or radiation therapy.

Question 2019

Topic: Surgical Anatomy & Approaches

A 50-year-old male is undergoing a Smith-Petersen approach for excision of a benign tumor located on the anterior acetabulum. During the approach, after developing the internervous plane and reflecting the rectus femoris, the surgeon needs to open the hip joint capsule for direct visualization. Which of the following capsulotomy techniques is commonly employed to achieve wide exposure of the femoral head and acetabular articular surface?

. A. Posterior capsulotomy along the piriformis fossa.
. B. Transverse capsulotomy across the femoral neck.
. C. H-shaped capsulotomy or a longitudinal incision parallel to the femoral neck.
. D. Inferior capsulotomy along the pubofemoral ligament.
. E. Superior capsulotomy along the iliofemoral ligament.

Correct Answer & Explanation

. C. H-shaped capsulotomy or a longitudinal incision parallel to the femoral neck.

Explanation

Correct Answer: CWhen the hip joint needs to be opened via the Smith-Petersen approach (e.g., for intra-articular fracture reduction, arthroplasty, synovectomy, FAI, or tumor excision), a common and effective technique is an H-shaped capsulotomy or a longitudinal incision parallel to the femoral neck. The arms of the H extend superiorly and inferiorly, allowing for wide exposure of the femoral head, femoral neck, and acetabular articular surface, while preserving a cuff of capsular tissue for later repair.Why other options are incorrect:A. Posterior capsulotomy along the piriformis fossa:This is a technique used in posterior approaches to the hip, not the anterior Smith-Petersen approach.B. Transverse capsulotomy across the femoral neck:While a transverse incision might be made, an H-shaped or longitudinal incision provides better extensibility and allows for easier repair, minimizing the risk of instability. A purely transverse incision might also compromise vascularity to the femoral neck.D. Inferior capsulotomy along the pubofemoral ligament:While the pubofemoral ligament is part of the anterior capsule, an isolated inferior capsulotomy would not provide the broad exposure needed for most intra-articular procedures.E. Superior capsulotomy along the iliofemoral ligament:The iliofemoral ligament is the strongest anterior ligament and is crucial for hip stability. While the capsule is incised, directly incising along the entire length of the iliofemoral ligament as a primary capsulotomy technique is not standard for wide exposure, as it might compromise stability. The H-shaped or longitudinal incision typically works around or through less critical parts of the capsule while respecting the overall integrity for later repair.

Question 2020

Topic: Surgical Anatomy & Approaches

A 68-year-old female is undergoing a total shoulder arthroplasty via the deltopectoral approach for severe glenohumeral osteoarthritis. During the procedure, after the subscapularis tenotomy and medial retraction, the surgeon is performing an inferior capsular release to improve external rotation and posterior translation. Which of the following neurovascular structures is at the highest risk of iatrogenic injury during this specific maneuver?

. Axillary artery
. Musculocutaneous nerve
. Cephalic vein
. Axillary nerve
. Lateral pectoral nerve

Correct Answer & Explanation

. Axillary nerve

Explanation

Correct Answer: DExplanation:Theaxillary nerveis at the highest risk during an inferior capsular release via the deltopectoral approach. The case explicitly states: "The axillary nerve... courses inferiorly and then anteriorly, approximately 5-7 cm distal to the acromion, around the surgical neck of the humerus. It runs in close proximity to the inferior border of the subscapularis muscle and the inferior glenohumeral joint capsule. The anterior humeral circumflex artery typically accompanies the nerve anteriorly. These structures are highly susceptible to injury during inferior capsular releases, humeral head resection, and subscapularis dissection or repair. Meticulous protection with a blunt Hohmann retractor beneath the inferior border of the subscapularis is essential."A. Axillary artery:While part of the axillary neurovascular bundle, the axillary artery is situated more medially and deeper, typically protected by the conjoined tendon and pectoralis minor. It is at risk with extreme medial retraction, but less directly vulnerable during an inferior capsular release compared to the axillary nerve.B. Musculocutaneous nerve:This nerve enters the deep surface of the coracobrachialis muscle approximately 5-8 cm distal to the coracoid tip. It is at risk with aggressive medial retraction or mobilization of the conjoined tendon, but not directly during an inferior capsular release of the glenohumeral joint capsule.C. Cephalic vein:This superficial vein lies within the deltopectoral groove. It is managed early in the approach (usually retracted medially) and is not typically at risk during deep intra-articular maneuvers like capsular release.E. Lateral pectoral nerve:This nerve innervates the pectoralis major muscle. It is located more superiorly and medially, and while theoretically at risk with excessive superior dissection or muscle division, it is not directly threatened by an inferior capsular release.

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