3. Adult Reconstruction (Hip & Knee) MCQs

A patient experiences recurrent posterior dislocations of their THA. The acetabular component is evaluated on CT scan and found to be placed in 5 degrees of anteversion and 30 degrees of abduction. Which parameter falls outside the traditional Lewinnek safe zone and is contributing most to the instability?

What is the primary biological mechanism responsible for the aseptic loosening and osteolysis commonly seen in older generation polyethylene total hip replacements?

A 55-year-old man with a metal-on-metal THA presents with groin pain and a palpable mass. Serum cobalt and chromium levels are elevated. MARS MRI demonstrates a large solid and cystic mass. What is the most characteristic histological finding of the periprosthetic tissue in this scenario?

A 45-year-old active male is undergoing a THA. The surgeon selects a ceramic-on-ceramic bearing surface. What is the most commonly reported specific complication associated with this bearing coupling compared to other options?

Following a primary THA using a posterior approach, a patient exhibits a foot drop and inability to extend the great toe. Which specific portion of the sciatic nerve is most vulnerable to injury during this procedure?

A patient complains of groin pain starting 3 months after a cementless THA. The pain is worst when rising from a seated position. Examination shows pain with active hip flexion against resistance. Radiographs demonstrate an acetabular component in 10 degrees of retroversion with an overhanging anterior edge. What is the most likely diagnosis?

A 28-year-old male sustains a displaced femoral neck fracture in a motor vehicle collision. He is hemodynamically stable. What is the most appropriate surgical management to minimize the risk of avascular necrosis and nonunion?

A 65-year-old male complains of recurrent posterior dislocations following a primary total hip arthroplasty performed via a posterior approach. Radiographs show the acetabular cup is placed in 40 degrees of abduction and 0 degrees of anteversion. What is the most appropriate definitive management?

A 70-year-old male presents with a painful total hip arthroplasty that has been symptomatic for 18 months. Aspiration reveals 45,000 WBC/mcL with 90% polymorphonuclear cells. Radiographs show circumferential radiolucencies around a loose femoral stem. What is the gold standard surgical management?

A 74-year-old woman sustains a fall around her cemented total hip arthroplasty.

Radiographs demonstrate a periprosthetic fracture around a loose femoral stem, but the proximal femur bone stock remains adequate. According to the Vancouver classification, what is the most appropriate surgical treatment?

What is the primary clinical advantage of utilizing highly cross-linked polyethylene (HXLPE) compared to conventional polyethylene in total hip arthroplasty?

A 60-year-old male with a metal-on-metal total hip arthroplasty presents with increasing groin pain. MRI reveals a large, thick-walled cystic mass. Serum cobalt and chromium levels are significantly elevated. The pathogenesis of this complication is best described as:

A 52-year-old female complains of a high-pitched squeaking noise coming from her total hip arthroplasty during ambulation. The implant is a ceramic-on-ceramic bearing. Which of the following is the most significant risk factor for this phenomenon?

Trunnionosis, or mechanically assisted crevice corrosion, has emerged as a significant mode of failure in modern total hip arthroplasties. Which of the following implant characteristics most increases the risk of this complication?

A 55-year-old male complains of numbness and burning over the anterolateral aspect of his thigh following a primary total hip arthroplasty. Which surgical approach was most likely utilized?

A 68-year-old female presents with persistent anterior groin pain 6 months after a total hip arthroplasty. The pain is exacerbated by active straight leg raising and getting out of a car. Radiographs reveal the acetabular cup is in 45 degrees of abduction and 20 degrees of anteversion, with slight anterior overhang. What is the most appropriate initial management?

During a total hip arthroplasty via a posterior approach, the surgeon meticulously repairs the short external rotators and the posterior capsule to the greater trochanter. What is the primary established clinical benefit of this step?

A patient requires a revision total hip arthroplasty for massive osteolysis. Preoperative planning suspects pelvic discontinuity. Which of the following radiographic findings is most characteristic of this condition?

During surgical fixation of a displaced femoral neck fracture with three cannulated screws, an inverted triangle configuration is utilized. What is the primary biomechanical rationale for placing the inferior screw closely adjacent to the calcar?

A 55-year-old highly active man is undergoing a total hip arthroplasty (THA). He is particularly concerned about the longevity of the implants and volumetric wear. Which of the following bearing surface combinations is biomechanically proven to have the lowest volumetric wear rate?