EARLY RATE OF DISLOCATION AFTER HIP ARTHROPLASTY USING POSTERIOR APPROACH WITH CAPSULORRAPHY AND SIZE 22MM HEAD

Abstract

Objectives: Dislocation is one of the common complications of total hip Arthroplasty. Posterolateral approach and small femoral heads have been shown to be high-risk factors for dislocation of the implanted total hip prosthesis. The use of a posterior capsulorraphy has also shown to decrease the rate of dislocation with a posterolateral approach. The objective of this study was to evaluate the early dislocation rate using size 22 mm head and a Posterolateral approach augmented with a posterior capsulorraphy.

Methods: Questionnaire and case notes review of 148 patients operated at one institution by 3 different senior surgeons from Aug’03 to Jan’05. A posterior capsulorraphy was performed in all the patients. The primary outcome measure was the dislocation of the prosthetic hip within the first year of surgery.

Results: 4 of the 148 patients (2.7%) had an episode of dislocation during the first year of surgery. 3 patients were treated conservatively and 1 required operative intervention in the form of PLAD. Radiographic analysis of this patient showed excessive anteversion of the socket(28⁰⁾.

Conclusions: Studies have consistently shown an increased rate of dislocation with a Posterolateral approach and use of a size 22mm head. A recently published study by Berry et.al has shown a 12.1% dislocation rate with the use of this approach and size 22mm head. However posterior capsulorraphy was not performed in patients in this study group. Our study shows that performing a posterior capsulorraphy can reduce early dislocation rates using Posterolateral approach and size 22 mm head. The dislocation rate (2.7%) is comparable to any other approach and the use of a larger head size.

These patients continue to be monitored to evaluate long term outcomes with this approach. (301 words)