The rate of dislocation after primary total hip arthroplasty has decreased, but given the high volume of total hip arthroplasty procedures that are performed, dislocation remains a common complication.» The etiology of dislocation after total hip arthroplasty is multifactorial and depends on the patient's characteristics as well as the orthopaedic surgeon's operative techniques and decisions regarding implants.» A detailed assessment of the patient, preoperative planning, a thorough understanding of the anatomy, proper surgical technique, and knowledge of the biomechanics of the implant decrease the likelihood of dislocations following total hip arthroplasty.» The advent of new techniques and procedures has further reduced the occurrence of dislocation following total hip arthroplasty. However, should dislocation occur, primary management or revision total hip arthroplasty techniques provide excellent results to salvage the mobility and function of the hip.
With nearly 400,000 Americans undergoing total hip arthroplasty every year, total hip arthroplasty deserves the distinction of "operation of the century" 1,2 . Although the surgery drastically decreases pain, improves function, and increases quality of life, total hip arthroplasty is not without risk and failures. The most common reason for failure and indication for early revision is instability 3 . The rate of dislocation after primary total hip arthroplasty ranges from 0.2% to 10% and is as high as 28% with revision total hip arthroplasty, affecting thousands of patients per year 3-6 . Therefore, dislocation represents a major challenge to the orthopaedic surgeon and the health-care system. This article reviews patient risk factors, surgical techniques, implant design, and management strategies regarding total hip arthroplasty instability.
Risk FactorsTiming Dislocation is the most common early complication of total hip arthroplasty following primary implantation, and most dislocations occur within 3 weeks of the index procedure 7 . Of note, the timing of a first dislocation is a risk factor for having a second dislocation. Brennan et al. demonstrated that patients with a first-time dislocation at 13 weeks had an increased risk of occurrence of a second dislocation when compared with those who had a first-time dislocation at 3 weeks 8 . Therefore, early dislocation may be an indicator of instability due to surgical technique, including inadequate soft-tissue tensioning or lack of repair of the surgical approach, or patient noncompliance since even well-positioned implants will dislocate under these circumstances. In contrast, late first-time dislocations Disclosure: The authors indicated that no external funding was received for any aspect of this work. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSREV/A472).