The Bernese periacetabular osteotomy: is transection of the rectus femoris tendon essential?

The Bernese periacetabular osteotomy (PAO) traditionally is performed using the iliofemoral or the ilioinguinal approach with transection of the rectus femoris tendon attachments. Although a rectus-preserving approach has been developed, there is limited direct comparison data regarding the surgical safety, radiographic correction, and improvement in hip pain and function between the rectus-preserving and the classic approaches.

The purposes of this study were to determine whether preserving the rectus femoris tendon attachment would (1) reduce intraoperative blood loss and length of surgery; (2) improve Harris hip scores (HHS); (3) decrease the rate of complications; and (4) affect the radiographic correction when compared with the classic approach.

A retrospective matched cohort study was used to compare the endpoints listed above after PAO using a rectus-preserving approach versus the classic approach. Operative blood loss, preoperative and postoperative hematocrit, duration of surgery, HHS, and postoperative complications were recorded for the two groups. Pelvic radiographs were reviewed for measurement of the lateral center-edge angle, anterior center-edge angle, and Tönnis acetabular inclination angle. A total of 64 patients were included (32 in each group). Followup was at a minimum of 1 year (mean, 20 months; range, 13-44 months).

Blood loss (p = 0.2405), hematocrit change (p = 0.3277), and operative time (p = 0.3960) were similar between groups. At latest followup, the HHS improved in the rectus-preserving (mean improvement, 25; 95% CI, 21-29; p < 0.0001) and control groups (mean improvement, 21; 95% CI, 17-25; p < 0.0001) with no difference in HHS improvement between the groups (mean difference, 4.3; 95% CI, -1.6 to 10.1; p = 0.1523). The complication rate was 12.5% (four of 32) in the rectus-preserving group and 25% (eight of 32) in the classic approach groups, respectively (p = 0.2002). The rectus-preserving approach allowed for similar lateral center-edge angle (p = 0.4463), anterior center-edge angle (p = 0.0936), and Tönnis angle (p = 0.7953) improvement when compared with the classic approach.

The rectus-preserving approach for PAO is as safe and effective as the classic approach to achieve radiographic correction and HHS improvement at minimum 1 year. Additional investigation is needed to determine whether the rectus-preserving approach allows for improvement in functional recovery including hip flexion strength.