3. Adult Reconstruction (Hip & Knee) MCQs

A randomized controlled trial is conducted to compare a new implant against a standard implant for total hip arthroplasty. The study concludes that there is no statistically significant difference in the complication rates between the two implants (p = 0.15). However, five years later, a large, well-powered national registry demonstrates that the new implant actually has a significantly higher complication rate. The initial study's erroneous conclusion is an example of which of the following?

A new biomarker test for periprosthetic joint infection (PJI) is evaluated in a cohort of 200 patients undergoing revision arthroplasty. Fifty patients have a confirmed PJI, and the test is positive in 40 of them. The remaining 150 patients do not have PJI, and the test is positive in 30 of them. What is the negative predictive value (NPV) of this biomarker in this study?

A 72-year-old woman is undergoing revision total knee arthroplasty for aseptic loosening 14 years after the index procedure. Retrieval analysis of the ultra-high molecular weight polyethylene (UHMWPE) tibial insert reveals extensive macroscopic delamination, deep subsurface cracking, and gross pitting, primarily located within the medial compartment articulating surface. Which wear mechanism is predominantly responsible for this specific pattern of implant failure?

Highly cross-linked polyethylene (HXLPE) is the bearing surface of choice in modern total hip arthroplasty to reduce wear and subsequent osteolysis. Which of the following is a recognized biomechanical trade-off resulting from increasing the radiation dose during the cross-linking process?

Aseptic loosening secondary to polyethylene wear debris remains a major cause of late failure in total hip arthroplasty (THA). Which of the following modifications to conventional ultra-high molecular weight polyethylene (UHMWPE) has been proven to most significantly reduce volumetric wear rates?

A patient presents with anterior knee pain, particularly during stair climbing and descending. Patellar tracking issues are suspected. Which quadriceps muscle primarily contributes to the lateral pull on the patella, potentially exacerbating patellofemoral pain syndrome?

A patient with a patellar fracture undergoes surgical repair. To ensure proper patellar tracking and stability post-operatively, which of the following muscles acts as the primary dynamic medial stabilizer of the patella?

A 40-year-old male presents with deep, boring pain in the upper thigh and hip, exacerbated by weight-bearing. MRI shows evidence of avascular necrosis of the femoral head. Which of the following is typically the last anatomical location in the femoral head to receive arterial supply, making it particularly vulnerable to ischemia?

During a posterior approach to the hip for total hip arthroplasty, aggressive release of the short external rotators can endanger the primary blood supply to the femoral head. Which anatomical structure serves as the primary physical barrier protecting the deep branch of the medial circumflex femoral artery (MCFA) during this approach?

A 65-year-old female undergoes a total knee arthroplasty. To minimize postoperative pain while preserving quadriceps motor function for early ambulation, the anesthesiologist performs an ultrasound-guided adductor canal block. Which of the following nerves courses through the adductor canal and provides the primary target for this sensory block?

During a posterior approach to the hip for a total hip arthroplasty, the surgeon meticulously isolates and tags the short external rotators. To avoid avascular necrosis of the femoral head in a joint-preserving procedure, or to minimize bleeding, the deep branch of the medial circumflex femoral artery (MCFA) must be protected. At what specific anatomical location does the deep branch of the MCFA consistently run in relation to the short external rotators?

To preserve the blood supply to the femoral head during a surgical dislocation of the hip via a posterior approach, the surgeon must carefully protect the deep branch of the medial circumflex femoral artery (MCFA). Anatomically, the deep branch of the MCFA consistently courses in the interval between which of the following muscles?

A posterior approach (Kocher-Langenbeck) is utilized for a complex total hip arthroplasty. The surgeon takes extreme care to protect the major blood supply to the femoral head. The deep branch of the medial femoral circumflex artery (MFCA) is the primary blood supply. To avoid iatrogenic injury to this vessel during the approach, which anatomical relationship must be respected?

In total hip arthroplasty, placement of a screw in the anteroinferior quadrant of the acetabulum puts which of the following structures at greatest risk?

Where is the main arterial supply to the femoral head most vulnerable during a posterior approach to the hip (Kocher-Langenbeck)?

The predominant blood supply to the adult femoral head is provided by the:

During an anterior approach to the pelvis for a periacetabular osteotomy, the lateral femoral cutaneous nerve is at risk. What is its most common anatomic relationship to the anterior superior iliac spine (ASIS)?

During a standard medial parapatellar approach for a total knee arthroplasty, a branch of the saphenous nerve is frequently sacrificed. What is the typical resulting sensory deficit experienced by the patient?

A standard deltopectoral approach is utilized for a total shoulder arthroplasty. During the superficial dissection, the cephalic vein is identified in the deltopectoral groove. To best preserve venous drainage and minimize bleeding, how should the vein ideally be managed?

During a posterior approach to the knee for a popliteal artery injury, the vascular bundle is traced distally. The popliteal artery transitions into the posterior tibial and anterior tibial arteries as it exits the popliteal fossa by passing deep to the tendinous arch of which muscle?