Exploring Various Labral Reconstruction Techniques in an Ovine Hip Model: A Biomechanical Perspective

Abstract

Background:

Labral reconstruction using various graft materials, including autografts and allografts, is gaining popularity to address labral deficiencies. However, the biomechanical effects of graft size, type, and fixation techniques remain underexplored.

Purpose/Hypothesis:

The purpose was to evaluate the effects of graft size, graft type, tubularization, and anchor number on suction seal force and distractive stability in an ovine hip model. It was hypothesized that larger graft sizes and the use of allografts would improve the suction seal force and distractive stability compared with smaller grafts and fewer anchor numbers, while tubularization would have no significant effect.

Study Design:

Controlled laboratory study.

Methods:

A total of 40 sheep hip joints were randomly assigned to 5 groups. Labral excision was performed, followed by reconstruction using autografts or allografts. Ovine extensor tendons were chosen as autografts, whereas labrums from a different ovine hip were used for allografts. For group 1, autografts matching the original labral width were used. For group 2, autografts twice the original labral width were used. For group 3, allografts matching the original labral width were harvested from a different ovine hip. For group 4, autografts matching the original width were fixed with only 2 anchors. For group 5, autografts matching the original width were tubularized before use.

Suction seal force was measured before and after reconstruction using an electromechanical testing system. Statistical analyses included Mann-Whitney U and Wilcoxon signed-rank tests (P < .05).

Results:

Group 2 showed the highest improvement in suction seal force, outperforming all other groups (P < .01). Group 4 exhibited the lowest distractive stability among all groups. Tubularization (group 5) did not enhance biomechanical performance (P = .752). Group 3, reconstructed with an allograft, exhibited suction seal performance most closely approximating that of group 2, with no significant difference between them.

Conclusion:

The data from the ovine cadaveric model indicate that increasing the graft size enhances the suction sealing force; however, it remains below the measurements observed in an intact labrum. Furthermore, increasing the number of anchors and optimal graft selection improve postoperative biomechanical stability.

Clinical Relevance:

Optimizing graft size and fixation techniques in labral reconstruction may improve joint stability and suction seal function and may support surgical strategies aimed at improving outcomes and delaying the progression of osteoarthritis in patients with labral defects.