SCIENTIFIC PAPER Anterior Dislocation Following Primary Total Hip Replacement by the Posterior Approach — Aetiology and Treatment

Objective: Review of 5 patients after anterior dislocation of prosthesis following primary total hip replacements done from the posterior approach. Patients and Methods: The implanted prostheses included 3 hybrid hips and 2 cementless hips. Results: The mean age of the patients was 60 years. Dislocation occurred between 2 and 25 days after operation. All dislocations were treated by closed reduction. The hips were unstable in extension, adduction, and external rotation. Special splints were designed to protect the hips in the ‘safety zone’ of flexion, abduction, and internal rotation. After an average protection period of 2.7 weeks, all hips were stable after a mean follow-up of 31 months. Total anteversion angle was measured under fluoroscopy in 3 hips and this ranged from 50° to 75°. Conclusion: Anterior dislocation was proposed to be associated with excessive anteversion of the components. The special rehabilitation method was effective for treating anterior dislocation, even with sub-optimally positioned components.