Menu

3. Adult Reconstruction (Hip & Knee) MCQs

Practice Set 140 of 326

This practice set contains high-yield board review questions covering key concepts in 3. Adult Reconstruction (Hip & Knee). Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 2781

Topic: 3. Adult Reconstruction (Hip & Knee)

A 22-year-old man falls on an outstretched hand and sustains a scaphoid waist fracture, placing him at high risk for avascular necrosis of the proximal pole. The predominant intraosseous blood supply to the scaphoid enters at which specific location?

. Volar aspect of the proximal pole
. Volar aspect of the distal pole
. Dorsal ridge
. Tuberosity
. Scapholunate ligament

Correct Answer & Explanation

. Dorsal ridge

Explanation

Approximately 80% of the scaphoid's blood supply comes from branches of the radial artery that enter at the dorsal ridge. This blood supply travels in a retrograde fashion from distal to proximal, making proximal pole fractures highly susceptible to avascular necrosis.

Question 2782

Topic: 3. Adult Reconstruction (Hip & Knee)

The popliteal artery is at risk of injury during a high tibial osteotomy (HTO) or total knee arthroplasty. At the level of the knee joint line, what is the anatomical relationship of the popliteal artery to the vein and nerve?

. Artery is deepest (anterior) and most medial
. Artery is deepest (anterior) and most lateral
. Artery is most superficial (posterior) and central
. Artery is most superficial (posterior) and medial
. Artery is central and between the vein and nerve

Correct Answer & Explanation

. Artery is deepest (anterior) and most medial

Explanation

From superficial to deep (posterior to anterior), the order is Nerve, Vein, Artery. At the joint line, the popliteal artery is the deepest and most medial structure, placing it at high risk from over-penetrating instruments.

Question 2783

Topic: 3. Adult Reconstruction (Hip & Knee)

During a posterior approach to the hip for a total hip arthroplasty, the surgeon must be careful to protect the primary blood supply to the femoral head. Which of the following vessels provides the predominant blood supply to the adult femoral head?

. Medial femoral circumflex artery
. Lateral femoral circumflex artery
. Artery of the ligamentum teres
. Inferior gluteal artery
. Superior gluteal artery

Correct Answer & Explanation

. Medial femoral circumflex artery

Explanation

The medial femoral circumflex artery (MFCA) provides the primary blood supply to the adult femoral head via the lateral epiphyseal artery. It courses posterior to the femoral neck and must be protected during posterior hip approaches.

Question 2784

Topic: Total Hip Arthroplasty (THA)

During a posterior approach to the hip, protecting the primary blood supply to the femoral head is critical. The medial femoral circumflex artery (MFCA) courses deep to which of the following short external rotators?

. Superficial to the piriformis
. Superficial to the superior gemellus
. Deep to the quadratus femoris
. Inferior to the obturator externus
. Along the inferior border of the gluteus minimus

Correct Answer & Explanation

. Deep to the quadratus femoris

Explanation

The deep branch of the MFCA passes deep (anterior) to the quadratus femoris. To protect the blood supply to the femoral head during a posterior approach, the quadratus femoris should be released with a cuff or spared, and the obturator externus must remain intact.

Question 2785

Topic: 3. Adult Reconstruction (Hip & Knee)

The precarious blood supply of the scaphoid makes it prone to avascular necrosis following fracture. The primary blood supply enters the scaphoid at which location?

. Volar and proximal
. Volar and distal
. Dorsal and proximal
. Dorsal and distal
. Directly at the waist

Correct Answer & Explanation

. Dorsal and proximal

Explanation

The primary blood supply to the scaphoid arises from branches of the radial artery. It enters the bone dorsally at the distal pole, perfusing the proximal pole in a retrograde fashion.

Question 2786

Topic: Total Hip Arthroplasty (THA)

A posterior approach to the hip is performed. To protect the main blood supply to the adult femoral head, careful handling of which vessel is required, and where does it course?

. Lateral femoral circumflex artery running anterior to the neck
. Medial femoral circumflex artery running posterior to the obturator externus
. Medial femoral circumflex artery running superior to the piriformis
. Inferior gluteal artery running anterior to the quadratus femoris
. Artery of the ligamentum teres running inferiorly

Correct Answer & Explanation

. Medial femoral circumflex artery running posterior to the obturator externus

Explanation

The medial femoral circumflex artery provides the primary blood supply to the adult femoral head. It courses posterior to the obturator externus and anterior to the triceps coxae/quadratus femoris.

Question 2787

Topic: Total Hip Arthroplasty (THA)

When performing a posterior approach to the knee, the tibial nerve is identified in the popliteal fossa. Which of the following correctly describes its position relative to the popliteal artery and vein?

. Medial and deep
. Lateral and superficial
. Lateral and deep
. Medial and superficial
. Directly anterior

Correct Answer & Explanation

. Lateral and deep

Explanation

In the popliteal fossa, the sequence of structures from superficial (posterior) to deep (anterior) is nerve, vein, artery. The tibial nerve is lateral to the vessels proximally and crosses to medial distally.

Question 2788

Topic: Total Hip Arthroplasty (THA)

The deep branch of the medial femoral circumflex artery (MFCA) provides the primary blood supply to the femoral head. Prior to piercing the hip capsule, it courses posteriorly between which two muscles?

. Piriformis and superior gemellus
. Superior gemellus and obturator internus
. Obturator internus and inferior gemellus
. Inferior gemellus and quadratus femoris
. Quadratus femoris and obturator externus

Correct Answer & Explanation

. Quadratus femoris and obturator externus

Explanation

The deep branch of the MFCA runs anterior to the quadratus femoris but posterior to the obturator externus. It then travels superiorly along the posterior capsule to supply the femoral head, making it vulnerable during posterior approaches.

Question 2789

Topic: Total Hip Arthroplasty (THA)

The direct lateral (Hardinge) approach to the hip involves splitting the gluteus medius. To avoid denervating the anterior portion of the gluteus medius, the proximal split should not extend beyond what distance from the tip of the greater trochanter?

. 1 cm
. 3 cm
. 5 cm
. 8 cm
. 10 cm

Correct Answer & Explanation

. 5 cm

Explanation

The superior gluteal nerve innervates the gluteus medius, gluteus minimus, and tensor fasciae latae. Its main trunk courses approximately 5 cm proximal to the tip of the greater trochanter, marking the safe limit for proximal dissection.

Question 2790

Topic: Total Hip Arthroplasty (THA)

To preserve the primary blood supply to the adult femoral head during a posterior approach to the hip, which of the following structures must be carefully protected as it defines the upper limit of the deep dissection?

. Piriformis tendon
. Quadratus femoris
. Obturator externus
. Superior gemellus
. Gluteus minimus

Correct Answer & Explanation

. Quadratus femoris

Explanation

The medial circumflex femoral artery provides the primary blood supply to the adult femoral head. It courses posteriorly and is protected by the intact obturator externus muscle, making it a critical landmark to preserve during a posterior approach.

Question 2791

Topic: Total Hip Arthroplasty (THA)

During a posterior approach to the knee, the surgeon dissects through the popliteal fossa. From superficial to deep (posterior to anterior), what is the correct order of the major neurovascular structures encountered?

. Popliteal artery, Popliteal vein, Tibial nerve
. Tibial nerve, Popliteal vein, Popliteal artery
. Popliteal vein, Tibial nerve, Popliteal artery
. Tibial nerve, Popliteal artery, Popliteal vein
. Popliteal artery, Tibial nerve, Popliteal vein

Correct Answer & Explanation

. Tibial nerve, Popliteal vein, Popliteal artery

Explanation

In the popliteal fossa, from superficial (posterior skin) to deep (anterior/closest to the bone capsule), the structures are arranged strictly as Tibial nerve, Popliteal vein, and Popliteal artery. This makes the artery the most difficult to repair if injured.

Question 2792

Topic: Total Knee Arthroplasty (TKA)

A 50-year-old recreational runner presents with acute posteromedial knee pain after a minor squatting twisting injury. MRI demonstrates a medial meniscus posterior root tear with 4 mm of meniscal extrusion. If left untreated, this injury rapidly alters knee biomechanics to most closely resemble which of the following?

. An isolated anterior cruciate ligament tear
. A total medial meniscectomy
. A partial medial meniscectomy
. An isolated medial collateral ligament sprain
. A posterior cruciate ligament tear

Correct Answer & Explanation

. A total medial meniscectomy

Explanation

A posterior root tear of the medial meniscus completely disrupts the hoop stresses of the meniscus. Biomechanically, this is equivalent to a total medial meniscectomy and leads to rapid progression of unicompartmental osteoarthritis.

Question 2793

Topic: 3. Adult Reconstruction (Hip & Knee)

An 8-month-old child with a late-presenting dislocated hip undergoes a closed reduction and application of a spica cast in the operating room. An arthrogram is utilized to determine the 'safe zone' of Ramsey. What defines this safe zone?

. The arc of motion between maximum adduction and maximum extension
. The angle between 90 degrees of flexion and 120 degrees of flexion
. The arc of motion from maximum comfortable abduction to the angle of redislocation in adduction
. The arc of motion from maximum internal rotation to maximum external rotation
. The angle at which the femoral head achieves concentric reduction on the AP radiograph

Correct Answer & Explanation

. The arc of motion from maximum comfortable abduction to the angle of redislocation in adduction

Explanation

The safe zone of Ramsey is the arc of motion between the maximum comfortable abduction and the point of redislocation as the hip is brought into adduction. Immobilizing the hip within this zone helps maintain reduction while minimizing the risk of avascular necrosis.

Question 2794

Topic: 3. Adult Reconstruction (Hip & Knee)

During closed reduction of a dislocated hip in a 9-month-old child, the Ramsey safe zone is assessed. What defines the boundaries of this zone?

. The angle between maximal abduction and the point of re-dislocation in adduction
. The degree of hip flexion required to maintain the reduction
. The ultrasound alpha angle measured post-reduction
. The fluoroscopic teardrop distance
. The distance between the medial femoral metaphysis and the ischium

Correct Answer & Explanation

. The angle between maximal abduction and the point of re-dislocation in adduction

Explanation

The Ramsey safe zone is the arc of abduction between the angle of re-dislocation (lower limit) and the angle of maximal abduction (upper limit). Excessive abduction past this safe zone dramatically increases the risk of avascular necrosis.

Question 2795

Topic: 3. Adult Reconstruction (Hip & Knee)

A 3-year-old girl presents with a painless limp. Examination reveals a positive Trendelenburg sign. Radiographs show a dislocated left hip with a false acetabulum. What is the most appropriate surgical management?

. Closed reduction and spica casting
. Open reduction and capsulorrhaphy only
. Open reduction, femoral shortening osteotomy, and pelvic osteotomy
. Total hip arthroplasty
. Observation until skeletal maturity

Correct Answer & Explanation

. Open reduction, femoral shortening osteotomy, and pelvic osteotomy

Explanation

In children older than 2-3 years with a dislocated hip, open reduction combined with a femoral shortening osteotomy (to reduce AVN risk) and a pelvic osteotomy (to correct dysplasia) is the standard of care.

Question 2796

Topic: 3. Adult Reconstruction (Hip & Knee)

A 16-year-old patient who had a severe, unstable SCFE treated with in situ pinning 4 years ago now presents with severe hip pain and limited abduction. Radiographs show a collapsed, sclerotic femoral head with crescent signs. What is the most definitive surgical option for this patient?

. Core decompression
. Free vascularized fibular graft
. Total hip arthroplasty
. Hip arthrodesis
. Valgus intertrochanteric osteotomy

Correct Answer & Explanation

. Total hip arthroplasty

Explanation

This patient has advanced avascular necrosis with femoral head collapse secondary to an unstable SCFE. Total hip arthroplasty provides reliable pain relief and functional restoration when head-preserving procedures are no longer viable.

Question 2797

Topic: Total Knee Arthroplasty (TKA)

A 3-year-old girl presents with progressive bilateral genu varum and lateral thrust during gait. Radiographs show a sharp varus angulation at the proximal tibial metaphysis with breaking of the medial cortex. Which radiographic measurement is most useful to distinguish infantile Blount disease from physiologic bowing?

. Metaphyseal-diaphyseal angle (Drennan angle)
. Tibiofemoral angle
. Mechanical axis deviation
. Physeal slope angle
. Q angle

Correct Answer & Explanation

. Metaphyseal-diaphyseal angle (Drennan angle)

Explanation

The metaphyseal-diaphyseal angle (Drennan angle) is used to differentiate physiologic bowing from infantile Blount disease. An angle greater than 16 degrees is highly predictive of Blount disease.

Question 2798

Topic: Total Hip Arthroplasty (THA)

A 4-year-old boy sustains a nondisplaced proximal tibial metaphyseal fracture that is treated successfully in a long leg cast for 4 weeks. One year later, the parents bring him to the clinic concerned about a deformity in the injured leg. What is the most likely deformity and its anticipated natural history?

. Progressive varus deformity requiring a corrective osteotomy
. Valgus deformity (Cozen's phenomenon) that typically remodels and resolves spontaneously
. Valgus deformity requiring a corrective osteotomy within 6 months
. Recurvatum deformity that requires immediate bracing
. Leg length discrepancy requiring epiphysiodesis

Correct Answer & Explanation

. Valgus deformity (Cozen's phenomenon) that typically remodels and resolves spontaneously

Explanation

Cozen's phenomenon is a valgus overgrowth deformity that occurs after proximal tibial metaphyseal fractures in children. It typically peaks at 12 to 18 months post-injury and generally remodels spontaneously over 2 to 3 years.

Question 2799

Topic: 3. Adult Reconstruction (Hip & Knee)

Figure 46 shows the AP radiograph of an active 80-year-old patient with an acetabular fracture. The fracture was initially managed nonsurgically; however, the patient is now scheduled to undergo total hip arthroplasty. What is the treatment of choice for the contained acetabular bone defect?

. Bipolar femoral component
. Acetabular cage
. Large structural allograft
. Use of the femoral head
. Double-bubble acetabular cup

Correct Answer & Explanation

. Use of the femoral head

Explanation

Acetabular fractures can result in a relative or actual acetabular bone defect. The medial blow-out fracture of the acetabulum has united well in this patient. It is likely that a medial shell of bone will be present during hip arthroplasty. The femoral head may be used as morcellized or structural bone to augment the medial defect and is preferred to structural allograft. Bipolar hip arthroplasty is notorious for medial migration in patients without a medial bone defect; therefore, it will not be a good choice in this patient. Filling the defect with methylmethacrylate cement, though an option, is not the best option in this active patient with an extensive medial defect. A double-bubble acetabular cup is used for patients with deficiency of the bone in the dome region. Mears DC: Surgical treatment of acetabular fractures in elderly patients with osteoporotic bone. J Am Acad Orthop Surg 1999;7:128-141.

Question 2800

Topic: 3. Adult Reconstruction (Hip & Knee)

A patient with a valgus knee and lateral compartment bone loss undergoes a total knee arthroplasty using posterior condylar referencing instrumentation. Six months after surgery, the patient reports significant anterior knee pain, and radiographs reveal severe lateral patellar tilt. Management should consist of

. lateral retinacular release.
. femoral component revision.
. medialization of the patellar component.
. patellectomy.
. tibial tubercle transfer.

Correct Answer & Explanation

. femoral component revision.

Explanation

Severe valgus deformity is frequently accompanied by hypoplasia of the lateral femoral condyle. Posterior referencing instrumentation can substantially internally rotate the femoral component with respect to the transepicondylar axis and Whiteside's line. The femoral component malrotation must be corrected to properly address this problem. Berger RA, Della Valle CJ, Rubash HE: Patellofemoral problems in total knee arthroplasty, in Callaghan JJ, Rosenberg AG, Rubash HE, et al (eds): The Adult Knee. Philadelphia, PA, JB Lippincott, 2003, vol 2, pp 1245-1258.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page