Review Question - QID 215613

Hip outcome scores are thought to be improved with total hip arthroplasty (THA) compared to hemiarthroplasty in a patient who is a previously active, independent ambulator.

Femoral neck fractures are increasingly common in the elderly population. Displaced femoral neck fractures, specifically, are usually treated with arthroplasty because of the damage to the blood supply with initial displacement, and risk for AVN. Indications for THA have been increasing relative to hemiarthroplasty, as the longevity of THA implants improve. This is likely due to the fact that THA has shown more reliable pain relief, lower re-operation rates, and improved outcome scores compared to hemiarthroplasty. However, not all displaced femoral neck fractures are indicated for THA, especially in patients with a high risk of instability (e.g. dementia). The best indication for THA compared to hemiarthroplasty in this case is the active patient who was a prior independent community ambulator without assistive devices.

Hedbeck et al. performed a retrospective review of 120 displaced femoral neck fractures, comparing outcomes between those treated with bipolar hemiarthroplasty or THA. Harris hip scores were significantly improved in the THA group at all time intervals (24 and 48 months), as were the quality of life indices at 24 months). They conclude that THA is a better option with regards to hip function and quality of life in elderly patients without dementia who sustain a displaced femoral neck fracture.

Zhou et al. performed a meta-analysis specifically reviewing hemiarthroplasty, comparing the outcomes between unipolar and bipolar designs. They found no difference in dislocation rate, reoperation, acetabular erosion, mortality, and noted postoperative outcome scores to be similar. They concluded there was no difference between the use of unipolar and bipolar hemiarthroplasty components in this cohort.

Incorrect Answers:
Answer 1: The dislocation rate of THA is higher than hemiarthroplasty. In a patient with risk factors for instability (neuromuscular disease, dementia), a hemiarthroplasty may be more appropriate.
Answer 3: No difference in the rate of intra-operative complications has been demonstrated with THA compared to hemiarthroplasty.
Answer 4: In this patient, outcomes of THA would be expected to be improved compared to both unipolar and bipolar hemiarthroplasty.
Answer 5: THA does not place patients at increased mortality risk compared to hemiarthroplasty.