The effect of EPSTR and minimal incision surgery on dislocation after THA.

Dislocation rates after posterior approach THA have decreased with the advent of enhanced posterior soft tissue (EPSTR) repairs that incorporate the external rotators. We examined three posterior approaches (simple posterior repair, EPSTR, and posterior minimal incision surgery using enhanced posterior soft tissue repair) performed by one surgeon in 390 consecutive primary THA operations (390 patients) from 1992-2003. A simple posterior repair of the external rotators done through three drill holes was performed in the first 90 patients. EPSTR incorporating the external rotators and posterior capsule in one continuous sleeve was performed in 180 patients. A 10 cm mini incision with EPSTR was performed in 120 patients. The overall dislocation rate for the series was 2.3% (9 of 390 procedures) with a 1% (4 of 390 procedures) revision rate for dislocation. The simple repair group had a greater dislocation rate (5.5%) compared to the group with EPSTR (1.3%) and the minimal incision with EPSTR group (1.7%). EPSTR decreased dislocation after total hip arthroplasty performed with a posterior approach. A 10 cm mini incision posterior approach with EPSTR maintained the low dislocation rate. Revision rate for dislocation was equivalent between the 3 groups.