Total Hip Arthroplasty (THA) MCQs

During a primary total hip arthroplasty using a posterior approach, the surgeon decides to use a 'high offset' femoral stem instead of a standard offset stem. Assuming the neck angle remains the same, how does this stem primarily affect hip biomechanics?

A patient is undergoing revision of a failed metal-on-metal total hip arthroplasty due to severe trunnionosis. The well-fixed titanium femoral stem will be retained, but the trunnion is macroscopically damaged. Which of the following head component combinations is most appropriate to place on the damaged trunnion?

A 60-year-old highly active man undergoes a primary total hip arthroplasty using a ceramic-on-ceramic bearing. Two years postoperatively, he complains of a reproducible, audible squeaking sound from the hip during deep flexion. Radiographs show a well-fixed implant but with a steeply positioned acetabular component. What is the most likely biomechanical cause of the squeaking?

To protect the deep branch of the medial femoral circumflex artery (MFCA) during a posterior approach to the hip, the surgeon should carefully avoid aggressive dissection and electrocautery at the upper border of which of the following muscles?

During a direct lateral (Hardinge) approach to the hip, the gluteus medius is split longitudinally. To prevent denervation of the anterior portion of the gluteus medius and minimus, the proximal split should not extend beyond what distance from the tip of the greater trochanter?

The medial circumflex femoral artery (MCFA) is at risk during a posterior approach to the hip if the dissection extends too far inferiorly. The MCFA typically passes between which two muscles before entering the hip capsule?

During a posterior approach to the hip, the surgeon identifies the medial femoral circumflex artery (MFCA) to protect the blood supply to the femoral head. What is the correct anatomic course of the main branch of the MFCA?

During a direct lateral (Hardinge) approach to the hip, proximal splitting of the gluteus medius must be limited to avoid denervating the anterior portion of the muscle. What is the generally accepted safe distance from the tip of the greater trochanter?

A surgeon uses the direct lateral (Hardinge) approach to the hip, which involves splitting the gluteus medius. To avoid denervating the anterior portion of the gluteus medius and tensor fasciae latae, the split should not extend proximally from the tip of the greater trochanter more than:

During a posterior approach to the hip, the short external rotators must be identified and tagged. Which of the following structures exits the pelvis through the lesser sciatic foramen?

To avoid denervation of the hip abductors during a direct lateral (Hardinge) approach to the hip, the proximal split of the gluteus medius should be limited to what maximum distance from the tip of the greater trochanter?

During a total hip arthroplasty, the surgeon uses a high-offset femoral stem to restore the patient's native anatomy. What is the primary biomechanical effect of increasing femoral offset on hip kinematics and joint reaction forces?

During a posterior approach to the hip (Kocher-Langenbeck), the blood supply to the femoral head via the deep branch of the medial femoral circumflex artery (MFCA) is at risk. Which of the following structures acts as the primary anatomic barrier protecting the MFCA and should generally be preserved?

A 55-year-old female sustains a Dubberley Type 3B capitellum-trochlea fracture, characterized by a highly comminuted articular fragment involving the posterior condyle with complete loss of soft tissue attachment. Which surgical approach provides the best exposure for internal fixation?

Which of the following describes the 'stress-shielding' phenomenon observed in orthopedic implants?

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

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 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?

When performing a direct lateral (Hardinge) approach to the hip, proximal splitting of the gluteus medius must be strictly limited to less than 3 to 5 cm from the tip of the greater trochanter. This safe zone prevents denervation of the muscle by protecting which nerve?

A patient undergoes a primary THA via a direct anterior approach. Postoperatively, they report a burning sensation and numbness over the anterolateral aspect of the operative thigh. Which nerve is most likely affected, and where is it most vulnerable during this surgical exposure?