The morphometric variability of the acetabular labrum: Insights for personalised hip labral reconstruction

Abstract

Background/objectives: The acetabular labrum plays a key role in hip biomechanics, reducing contact pressure and peak stress on articular cartilage. In femoroacetabular impingement (FAI), injuries often require surgical intervention. While anatomical repair restores function, irreparable cases necessitate labral reconstruction with grafts. Despite advancements, detailed morphometric studies remain limited. This study analyses labral morphometry, focusing on regional and sex-based differences to optimise graft selection. Materials and methods: 18 adult hip specimens were included after screening for normal hip morphometry on fluoroscopy (Wiberg 25-40 degrees, alpha angle <55 degrees, preserved joint space; Tonnis <2) and verification of intact labral and chondral structures after dissection. Morphometric measurements included labrum height (anterior,superior,posterior), acetabular diameter, anterior superior iliac spine (ASIS) distance, and transverse ligament (TAL) width. Specimens were analysed regionally and stratified by sex. Statistical comparisons identified morphometric differences. Results: Labrum height was greatest in the posterior (7.49 +/- 0.95 mm), followed by the superior (6.78 +/- 0.91 mm) and anterior (5.60 +/- 0.71 mm) regions. Statistically significant (p < 0.05) sex-based differences were observed in all measurements. Males exhibited greater labral height in the superior (7.19 +/- 1.02 mm vs. 6.29 +/- 0.91 mm), posterior (7.38 +/- 0.66 mm vs. 6.93 +/- 0.70 mm), and anterior (5.49 +/- 1.03 mm vs. 5.03 +/- 0.71 mm) regions. Additionally, males had larger transverse ligament width (7.04 +/- 0.68 mm vs. 6.66 +/- 0.63 mm), ASIS distance (285.73 +/- 7.12 mm vs. 275.88 +/- 9.24 mm), and acetabular diameter(54.35 +/- 2.76 mm vs. 50.29 +/- 4.97 mm). Conclusions: The acetabular labrum shows progressive height variation - posterior > superior > anterior - with males exhibiting approximately 1 mm greater dimensions across all regions. These anatomical differences should guide graft selection and surgical planning to optimise patient-specific hip preservation and outcomes.