The influence of intraoperative pretensioning on the chondroprotective effect of meniscal transplants.

Abstract

Meniscal replacement has become more common in recent years. The meniscal transplant's ability to transfer load effectively depends on its ability to bear circumferential loading. Intraoperative pretensioning on the meniscal transplant sutures has a positive influence on meniscal transplants' chondroprotective effect. Controlled laboratory study. Thirty-six sheep were divided into 6 groups (n = 6), subjected to a sham operation (group A), a meniscectomy (group B), or a meniscal autograft using tag sutures with different levels of pretensioning (group C, 0 N; group D, 20 N; group E, 40 N; group F, 60 N). Macroscopic (International Cartilage Repair Society score) and histologic evaluations (Mankin score) of the articular cartilage were performed after 6 months. Higher suture pretension (40 N, 60 N) resulted in less cartilage degeneration than in meniscectomized (P =.047; P =.036) and nonpretensioned (P =.028; P =.015) knees, with International Cartilage Repair Society scores of 1.63 +/- 0.57 and 1.66 +/- 0.51 in groups E and F, respectively, and scores of 2.40 +/- 0.27 and 2.68 +/- 0.46 observed after meniscectomy and meniscal transplantation with no pretensioning, respectively. Group F had a significantly better Mankin score of 6.66 +/- 2.15 (P =.05) compared with group D. Regarding criterion cells, trends toward less degeneration compared with meniscectomized and nonpretensioned knees (P = .054 and P =.055) were found. The coefficient of variation of the Mankin scores was greater than that of the International Cartilage Repair Society score. Group A had significantly better cartilage than all other groups. Adequate intraoperative pretensioning has a significant influence on the chondroprotective effect of meniscal transplants but did not prevent the development of articular cartilage degeneration. The results suggest that intraoperative pretensioning could improve the chondroprotective effect of meniscal transplantation.