Abstract

Dislocation in primary total hip arthroplasty is common and problematic and is attributable to several factors, including previous hip surgery, neuromuscular disorders, cerebral dysfunction, psychosis, alcoholism, and female gender. Factors under the control of the surgeon include component orientation and restoration of soft-tissue tension. Prosthetic factors lowering the risk of dislocation include increasing the size of the prosthetic femoral head, keeping femoral neck circumference to a minimum, and optimizing the geometry of the acetabular component. Postoperatively, patients should be expected to comply with standard hip precautions. Treatment is with immediate closed reduction. Multiple dislocations can be treated by advancing the trochanter in the presence of inadequate soft-tissue tension, revision arthroplasty in the presence of malpositioned components, or the use of a constrained cup when intraoperative instability persists. Because the risk of redislocation is much higher than that for first-time dislocation, prevention is critical. An enhanced repair technique can be used to reconstruct the posterior soft-tissue sleeve during the posterior surgical approach. This technique has been successful in lowering the dislocation rate from 4% to 0% in a series of 395 consecutive patients.