Different methods of posterior capsule and external rotators reparation in total hip arthroplasty.

Abstract

Objective To explore the validity of different methods used to repair posterior capsule and external rotators in primary total hip arthroplasty. Methods Forty-three patients (37 males, 6 females) undergoing unilateral total hip arthroplasty for unilateral femoral head avascular necrosis were selected, aging from 31 to 52 years old (average 45.6 years old). The surgery was performed via conventional pesterolateralapproach. The patients were randomized into two groups: 21 cases had their posterior capsule and external rotators reattached to the posterior edge of femoral greater trochanter (bony reattachments), whereas the other 22 cases had their posterior structures reattached to inferior posterior edge of the gluteus medius muscle (soft tissue reattachment). The patients in both groups were evaluated with Harris scores before operation, 6 weeks and 3 months after operation. The integrity of reattachment was double blinded detected by type B ultra- sonography at the 6th week and the 3rd month after operation. Discontinuance for more than 50% of repaired tissue was defined as poor continuity and repair failure. Results Harris scores before operation, 6 weeks and 3 months after operation in both groups showed no significant difference. Ultrasonic inspection at 6 weeks and 3 months after operation both showed that the rate of good repair was 57.1% (12/21) for the group of bony reattachment and 86.4% (19/22) for the group of soft tissue reattachment (χ2=4.560,P=0.033). Con-dusion Failure rate of reattachment of posterior capsule and external rotators to posterior edge of the greater trochanter is higher than that of posterior structures reattachment to the inferior posterior edge of the gluteus medius muscle. Soft tissue reattachment of posterior structures during THA is recommended. Key words: Arthroplasty, replacement, knee; Femur head necrosis; Ultrasonography