INTRAOPERATIVE PRE-TENSIONING ON MENISCAL TRANSPLANTS IN AN OVINE MODEL – EVALUATION OF THE CHONDROPROTECTIVE EFFECTS

Introduction: The goal of meniscal transplantation is to prevent progressive joint degeneration that predictably follows meniscectomy. The meniscal transplant’s ability to transfer load effectively depends on its ability to bear circumferential loading. Purpose of this study was thus to investigate the influence of intraoperative pre-tensioning on the chondroprotective of meniscal transplants in a sheep model. Methods: 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 pre-tensioning (group C, 0 N; group D, 20 N; group E, 40 N; group F, 60 N). Macroscopic (International Cartilage Repair Society score) and histological evaluation (Mankin score) of the articular cartilage was performed after 6 months. Results: Higher suture pretension (40 N, 60 N) resulted in less cartilage degeneration than in meniscectomized (P =.047; P =.036) and non-pre-tensioned (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 pre-tensioning, 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 non-pretensioned 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. Conclusion: Adequate intraoperative pre-tensioning has an influence on the chondroprotective effect of meniscal transplants but did not prevent the development of articular cartilage degeneration. Clinical Relevance: The results suggest that intraoperative pre-tensioning could improve the chondroprotective effect of meniscal transplantation.