Total Hip Arthroplasty (THA) MCQs

Trunnionosis, or wear at the head-neck junction of a modular femoral stem, has become increasingly recognized in total hip arthroplasty. Which of the following implant combinations represents the highest risk factor for developing symptomatic trunnionosis?

During the posterior approach to the hip, protecting the blood supply to the femoral head in the setting of a femoral neck fracture is not required; however, understanding the vascular anatomy is critical to limit bleeding. The medial femoral circumflex artery (MFCA) provides the primary blood supply to the head. Where is the deep branch of the MFCA anatomically located during this approach?

When templating for a total hip arthroplasty, the surgeon notes an anticipated leg length discrepancy. Lowering the center of rotation of the acetabular component without changing the femoral neck cut or stem size will result in which of the following?

A 55-year-old male with a history of severe slipped capital femoral epiphysis (SCFE) undergoes a total hip arthroplasty. During the operation, the surgeon finds it difficult to restore femoral offset without excessively lengthening the limb. Sinking the femoral stem deeper is not possible due to a narrow diaphysis. What is the most appropriate next step?

While performing an anterolateral approach to the hip, the surgeon proceeds to release the reflected head of the rectus femoris to improve acetabular exposure. Ligation of which of the following vascular structures is necessary to prevent significant hemorrhage during this step?

An MRI of the hip reveals an intra-articular mass requiring a surgical dislocation via a posterior approach. To protect the deep branch of the medial circumflex femoral artery (MCFA), the tendon of which muscle must be preserved or carefully handled?

During a direct lateral (Hardinge) approach to the hip, the anterior third of the gluteus medius is split to gain access to the joint. Splitting the muscle too proximally risks denervating the remaining anterior portion of the muscle. What is the accepted safe zone for splitting the gluteus medius proximal to the tip of the greater trochanter to avoid injuring the superior gluteal nerve?

Which of the following histological findings is pathognomonic for an Aseptic Lymphocyte-Dominated Vasculitis-Associated Lesion (ALVAL) in the setting of a failed metal-on-metal THA?

A 55-year-old female underwent THA with a ceramic-on-ceramic bearing. At her 2-year follow-up, she complains of a loud squeaking noise from her hip when bending to tie her shoes. Which of the following factors is most strongly associated with squeaking in ceramic-on-ceramic THA?

A dual mobility cup is often used in revision THA to reduce the risk of dislocation. Which of the following best describes the primary biomechanical principle of a dual mobility construct?

When planning a primary THA, the surgeon uses the AP pelvis radiograph to assess leg length discrepancy.

Which of the following radiographic landmarks is most reliable for establishing a horizontal reference line for leg length measurement?

Biomechanical optimization during Total Hip Arthroplasty (THA) is crucial for longevity and function. Increasing the femoral offset during a THA has which of the following mechanical effects?

A 78-year-old female with a history of recurrent dislocations following a primary total hip arthroplasty is scheduled for revision surgery.

The surgeon decides to use a dual mobility construct. What is the defining biomechanical feature of a dual mobility articulation?

A 65-year-old female presents with recurrent posterior dislocations following a primary THA. Radiographs demonstrate adequate acetabular component position, but the femoral component has decreased offset compared to the contralateral side. Increasing the femoral offset during revision provides which of the following biomechanical advantages?

During acetabular preparation in THA, a screw is placed in the anterior-superior quadrant of the acetabulum based on the Wasielewski safe zones. Which neurovascular structure is at greatest risk of injury?

A 62-year-old female is undergoing a direct anterior approach for a THA. The surgeon utilizes the interval between the tensor fasciae latae and the sartorius. Which of the following structures is at the highest risk of injury during the initial superficial dissection?

A 45-year-old active male underwent a total hip arthroplasty utilizing a ceramic-on-ceramic bearing. Two years later, he complains of an audible squeaking sound from the hip during deep flexion activities. Which of the following factors is most strongly associated with the development of this phenomenon?

During templating for a primary THA, the surgeon notes a 15 mm leg length discrepancy (affected leg is short) and a highly offset native femur. If a standard offset stem is used instead of a high offset stem, what compensatory intraoperative error is most likely to occur in an attempt to restore soft tissue tension?

A 42-year-old highly active female undergoes THA using a ceramic-on-ceramic bearing. One year later, she complains of a loud, audible squeaking noise from the hip during specific movements, though she is pain-free. What is the most significant risk factor for this phenomenon?

A 75-year-old male with Parkinson's disease and a history of recurrent posterior hip dislocations is scheduled for revision THA. A dual mobility construct is selected. What is the primary biomechanical advantage of a dual mobility bearing that reduces dislocation risk?