Suture-Only Fixation Technique Leads to a Higher Degree of Extrusion Than Bony Fixation in Meniscal Allograft Transplantation

Abstract

Background:

Most of the published series of transplanted menisci have consistently shown some degree of allograft extrusion. The speculation is that this meniscal extrusion may be caused by the soft tissue technique used to fix the allograft.

Hypothesis:

The percentage of extruded meniscal graft would be higher if the allograft were only fixed with sutures rather than with associated bony fixation.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We performed a prospective series of 88 meniscal allograft transplantations. Thirty-three of the grafts were fixed with the suture-only technique (group A). The remaining 55 cases were performed with the bone plug method (group B). All patients were studied with magnetic resonance imaging (MRI) at a minimum 3 years’ follow-up to determine the degree of meniscal extrusion. The time between surgery and MRI evaluation was 40 months (range, 36-48 months) in both groups. Meniscal extrusion was measured on coronal MRI. The percentage of the meniscal body width that was extruded was calculated. The average percentage of extrusion for each group was compared. The Lysholm score was analyzed in relation to the fixation method and degree of meniscal extrusion. Tears of the allograft that required surgical intervention were also reported.

Results:

The average percentage of meniscal tissue extruded in group A was 36.3% ± 13.7% without differences between the medial (35.9% ± 18.1%) and lateral (38.3% ± 14.4%) compartments (P = .84). Group B had a mean 28.13% ± 12.2% of the meniscal body extruded without differences between the medial (25.8% ± 16.2%) and lateral (30.14% ± 13.5%) compartments. A higher percentage of extruded meniscal tissue was found in group A than in group B (P < .001). No association between the degree of meniscal extrusion and the functional score was observed (P = .4). Graft tears were observed in 21.4% of the cases in group A and in 7.3% of the cases in group B (P = .09).

Conclusion:

A meniscal allograft fixed with the suture-only technique showed a significantly higher degree of extruded meniscal body than that fixed with the bony fixation method, with no influence on the functional outcome. There was also a considerably higher rate of graft tears observed in those menisci fixed only with sutures, although this difference was not statistically significant with the numbers available.