1. General Principles & Basic Science MCQs

During an anterior intrapelvic (modified Stoppa) approach to the acetabulum, the surgeon must identify and ligate the 'corona mortis'. This structure represents an anastomosis between which two vascular systems?

A surgeon utilizes the anterior (Smith-Petersen) approach for an open reduction of a developmental dysplasia of the hip. What is the superficial internervous plane utilized in this approach?

During an ilioinguinal approach for an anterior column acetabular fracture, the surgeon must mobilize contents within three distinct surgical windows. Which of the following structures is primarily isolated and protected in the middle window?

When performing a direct lateral (Hardinge) approach to the hip, proximal extension of the incision into the gluteus medius must be strictly limited to avoid injury to which of the following nerves?

During an intrapelvic (modified Stoppa) approach for acetabular fracture fixation, significant hemorrhage is encountered while dissecting over the superior pubic ramus. This bleeding is most likely originating from an anastomosis (corona mortis) between which two vascular systems?

A 35-year-old man is brought to the emergency department after a high-speed motor vehicle collision. He has a shortened, internally rotated, and adducted right lower extremity. Following closed reduction of the hip, he is noted to have a foot drop and inability to extend his great toe. Which specific nerve division is most likely injured?

During an anterior (Smith-Petersen) approach to the hip, the superficial internervous plane lies between which two muscles?

During an ilioinguinal approach to the acetabulum, severe bleeding occurs as the surgeon dissects near the superior pubic ramus. This is most likely due to an injury to an anastomotic vessel connecting the obturator system and the:

Which of the following vessels provides the primary blood supply to the weight-bearing portion of the adult femoral head?

A 65-year-old woman undergoes a primary total hip arthroplasty via a direct lateral (Hardinge) approach. Postoperatively, she demonstrates a severe, persistent Trendelenburg gait. Iatrogenic injury to which of the following structures is the most likely cause?

A surgeon is performing a direct anterior (Smith-Petersen) approach to the hip for a total hip arthroplasty. The superficial surgical dissection utilizes an internervous plane between two muscles. Which of the following defines this interval?

During a primary total hip arthroplasty for a patient with bilateral Crowe type IV developmental dysplasia of the hip, the surgeon plans to restore the hip center of rotation to the true anatomic acetabulum. What intraoperative step is frequently required to minimize the risk of postoperative sciatic nerve palsy?

A 35-year-old woman presents with bilateral groin pain and is diagnosed with Ficat Stage II avascular necrosis (AVN) of the femoral head. She undergoes core decompression. What is the primary biological mechanism by which this procedure is thought to relieve pain and promote healing?

The direct anterior approach (Smith-Petersen) to the hip is favored by some surgeons due to its true internervous plane. Which two nerves supply the muscles that form the boundaries of this superficial surgical interval?

A patient undergoes a primary total hip arthroplasty utilizing a direct lateral (Hardinge) approach. Postoperatively, the patient demonstrates a pronounced Trendelenburg gait and persistent abductor weakness. Injury to which of the following nerves is the most likely iatrogenic cause?

A 68-year-old woman who has been taking alendronate for 8 years presents with a transverse, non-comminuted fracture of the femoral shaft with a medial spike. What is the primary underlying mechanism of this fracture?

A 35-year-old man sustains a transverse acetabular fracture with predominant displacement of the posterior column following a motor vehicle collision. Which surgical approach is most appropriate for direct visualization and reduction of the primary displacement?

Highly cross-linked polyethylene (HXLPE) is widely used in modern THA to reduce wear rates. What is the primary mechanical trade-off associated with increasing the radiation dose used to create cross-linking in polyethylene?

A 65-year-old active man undergoes a total hip arthroplasty using a highly cross-linked polyethylene liner. Which of the following mechanical properties is most significantly decreased in highly cross-linked polyethylene compared to conventional ultra-high-molecular-weight polyethylene (UHMWPE)?

A 45-year-old woman with a history of systemic lupus erythematosus presents with severe groin pain. MRI confirms Ficat Stage II osteonecrosis of the femoral head without subchondral collapse. She undergoes a core decompression. What is the primary physiologic mechanism by which this procedure relieves pain?