gms | German Medical Science

Objectives: The acetabular labrum is a stabilizer of the hip joint and responsible for the suction seal. It is therefore recommended to preserve or reconstruct the labrum in joint preserving hip surgery instead of resecting it. The rationale of the technique is to preserve the intact tip of the labrum and to restore the volume with a graft of the Lig. teres inbetween bony rim and preserved part of the labrum. We present the technique and the preliminary results after 1 year.

Methods: From April 2013 to December 2015, we performed labral augmentation with ligamentum teres in 16 hips (11 right) in 16 patients (7 male, mean age 29 years) during surgical dislocation for treatment of femoro-acetabular impingement (FAI). An ap pelvic x-ray, lateral cross-table view of the hip and MR arthrography were obtained preoperatively. Joint degeneration was graded according to Tönnis. The acetabular Index (AI), the lateral center edge angle (LCE), asphericity angle (AA) and the acetabular retroversion index (ARI) were determined. The Merle d'Aubigné and Postel score (MdA) was calculated pre- and postoperatively. The Oxford Hip Score (OHS) was obtained at the 1 year followup. Surgical technique: After surgical dislocation of the hip, the ligamentum teres is resected and from it a graft with a width of 4-5 milimeters is created. The labrum is sharply detached from the acetabulum and trimming of the bony acetabulum is performed as needed. The ligamentum teres graft is sutured inbetween the acetabulum and the remaining labrum using bone anchors.

Results: Of the 16 hips, 4 had previous surgery (3 hip arthroscopy, 1 periacetabular osteotomy). There were seven grade 1 and nine grade 0 hips (Tönnis). Mean LCE was 29° (SD 4.9, range 25 to 39). The mean AI was 1.85° (SD 3.9, range -0.5 to 9.9). Mean AA was 62.5° (SD 12.4, range 52 to 106). Mean ARI was 23.4% (SD 10.8, range 6.4 to 40.0). Mean MdA improved from 14.5 (SD 0.93, range 13 to 16) preoperatively to 17 (SD 1.75, range 11 to 18) at 1 year (p< 0.0001). Main improvement in the MdA score was due to a reduction of pain with good walking ability and hip ROM pre and postoperatively. The mean OHS after one year was 42 (SD 9.1, range 17 to 48). Previous surgery was a risk factor for inferior results. Hips without previous surgery had a mean OHS of 44.5 (SD 6.6, range 29 to 48) versus 26 (SD 10.3, range 17 to 42) in the hips with previous surgery at latest follow-up. Regarding the MdA score, the mean score improved from 15 (SD 1.0, range 13 to 16) preoperatively to 17.5 (SD 0.8, range 17 to 18) in the group without previuos surgery versus 14 (SD 0.7, range 13 to 15) to 16 (SD 2.4, range 11 to 17) for the group with previous surgery. Whether this is statistically significant was not calculated because of the small sample size (4 hips) with previuos surgery.

Conclusion: Augmentation of the labrum using ligamentum capitis femoris shows good clinical results after one year. Patients with previous hip surgery had inferior results.