Review Question - QID 4614

Based on the radiographs and current literature, the best intervention is an uncemented metal on polyethylene total hip arthroplasty.

Avascular necrosis of the hip may be idiopathic in nature or associated with alcoholism, steroid use, or as in this case, sickle cell anemia. The Ficat staging system is used to classify avascular necrosis of the hip. Changes in treatment are driven by development of symptoms as well as the development of subchondral bone collapse (Ficat Stage 3). In those with with femoral head flattening (Ficat Stage 4) and acetabular degenerative changes (Ficat Stage 5), total hip replacement has good to excellent outcomes.

Mont et al. review surgical options for avascular necrosis of the hip. Head preserving procedures are generally reserved for those patients where the femoral head has not collapsed. Collapse and associated arthritis warrant utilization of arthroplasty procedures.

Mont et al. conducted a systematic review to better delineate the symptomatic progression of asymptomatic avascular necrosis of the hip. They found that patients with sickle cell disease have the highest rate of progression to collapse. Medium sized, laterally located lesions were associated with a higher frequency of collapse and joint preserving procedures are recommended for these.

Figure A shows radiograph of a patient with avascular necrosis; note the femoral head flattening, narrowing of the joint space and acetabular sclerosis.

Incorrect Answers:
Answer 1: Conservative measures in this patient would not improve this patient’s outcome give the degree of the femoral head collapse and presence of acetabular degeneration.
Answer 2: Bisphosphonates can be used in patients with avascular necrosis of the hip prior to collapse. Current data is conflicting as to whether they prevent collapse or not.
Answer 3: Outcomes for patients undergoing hemiarthroplasty for avascular necrosis of the hip in the young patient are poor; and as a result, this has been largely abandoned.
Answer 5: Higher failure rates have been seen in patients undergoing cemented total hip arthroplasty in treatment of avascular necrosis of the hip.