A Prospective Double-Blinded Randomized Controlled Trial Comparing the Direct Superior Approach Versus the Posterior Approach for THA.

BACKGROUND The direct superior approach (DSA) is a modification of the posterior approach (PA) that is intended to preserve the iliotibial band and short external rotators, except for the piriformis and conjoined tendon, during total hip arthroplasty (THA). The objective of this study was to compare postoperative pain scores between patients undergoing the DSA versus the PA for THA. METHODS This study included 80 patients with symptomatic hip arthritis undergoing primary THA. Patients were prospectively randomized to receive either the DSA or PA for THA. Surgery was undertaken using identical implant designs in both groups, and all patients underwent a standardized postoperative rehabilitation program. Predefined study outcomes were recorded by blinded observers at regular intervals for 2 years after THA. RESULTS Patients in the PA and DSA groups had comparable baseline characteristics for age (mean and standard deviation, 67.3 ± 7.4 and 67.8 ± 7.8 years, respectively; p = 0.962), sex (26 male and 14 female patients, and 21 male and 19 female patients, respectively; p = 0.499) and body mass index (29.0 ± 4.3 and 29.1 ± 5.3 kg/m2; respectively; p = 0.298). There was no significant difference between the PA and DSA groups with respect to postoperative pain scores at 24 hours as assessed using the visual analogue scale (4.5 ± 1.2 and 4.2 ± 2.0, respectively; p = 0.312). The overall time to hospital discharge was 43.6 ± 9.7 hours in the PA group and 45.4 ± 8.9 hours in the DSA group. Two patients in the PA group and 1 in the DSA group developed superficial wound infections, which were successfully treated with oral antibiotics. There were no further complications or harm sustained by patients in either treatment group. CONCLUSIONS This study showed that the intended benefits of the DSA in preserving the iliotibial band and the short external rotators, except for the piriformis and conjoined tendon, did not translate to any difference in postoperative pain scores when compared with the PA for THA. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.