Does the direct anterior approach in THA offer faster rehabilitation and comparable safety to the posterior approach?

Abstract

Background: Newer surgical approaches to THA, such as the direct anterior approach, may influence a patient's time to recovery, but it is important to make sure that these approaches do not compromise reconstructive safety or accuracy.

Questions/purposes: We compared the direct anterior approach and conventional posterior approach in terms of (1) recovery of hip function after primary THA, (2) general health outcomes, (3) operative time and surgical complications, and (4) accuracy of component placement.

Methods: In this prospective, comparative, nonrandomized study of 120 patients (60 direct anterior THA, 60 posterior THAs), we assessed functional recovery using the VAS pain score, timed up and go (TUG) test, motor component of the Functional Independence Measure™ (M-FIM™), UCLA activity score, Harris hip score, and patient-maintained subjective milestone diary and general health outcome using SF-12 scores. Operative time, complications, and component placement were also compared.

Results: Functional recovery was faster in patients with the direct anterior approach on the basis of TUG and M-FIM™ up to 2 weeks; no differences were found in terms of the other metrics we used, and no differences were observed between groups beyond 6 weeks. General health outcomes, operative time, and complications were similar between groups. No clinically important differences were observed in terms of implant alignment.

Conclusions: We observed very modest functional advantages early in recovery after direct anterior THA compared to posterior-approach THA. Randomized trials are needed to validate these findings, and these findings may not generalize well to lower-volume practice settings or to surgeons earlier in the learning curve of direct anterior THA.

Fig. 1

A flowchart demonstrates patient enrollment for the study.

Fig. 2

A photograph demonstrates operating room setup for the direct anterior approach performed on a standard operating table with a table mounted femoral elevator. The foot end of the table is dropped during femoral preparation to achieve the desired hip extension and the contralateral lower extremity is placed on a Mayo stand to allow adduction and external rotation for femoral exposure. A C-arm can be easily used as the pelvis and hips are placed on the radiolucent part of the operating table.

Fig. 3A–B

A scatterplot demonstrates variability of acetabular component placement with the (A) direct anterior approach and (B) posterior approach. Note smaller variances for the direct anterior approach.