The Dislocator, Early and Late: The Role of Large Heads

Abstract

Dislocation after total hip arthroplasty (THA) is a potentially devastating complication that can be difficult to manage. Many patient and mechanical factors have been associated with an increased risk of dislocation. Conservative treatments such as abduction bracing have not proven effective at treating this difficult problem. Surgical options include the use of larger femoral heads, unconstrained tripolar femoral heads, and constrained devices. While each device has its merits, there is no one-size-fits-all solution to this problem. With the development of highly cross-linked polyethylene and its superior wear characteristics and mechanical properties, the use of larger femoral heads is now available. Twenty-six hips in 25 patients who underwent revision surgery for recurrent dislocation were treated with a femoral head =/>36 mm in diameter. The direct lateral surgical approach was used in 24 hips, and the posterior and anterior supine intermuscular approaches were used in 1 hip each. One patient died 5 years after revision surgery, and 3 patients have not returned for clinical follow-up over the past 2 years. Four hips subsequently suffered a repeat dislocation, for a dislocation rate of 17%. Two patients underwent a subsequent surgery: 1 irrigation and debridement and 1 hardware removal. There have been no other revisions to date. Mean time to follow-up is 17.2 months. While the use of large femoral heads for the treatment of dislocation is warranted, continued follow-up is necessary.