Experimental study of polypropylene mesh implantation in the knee joint capsule defect

The problem of anterior cruciate ligament (ACL) reconstruction of the knee joint remains relevant, despite of significant number of designed surgical techniques for its reconstruction. Repeated ruptures of the restored ACL are recorded in 3–15 % of cases. Objective: to determine the morphological features of the knee joint tissues rearrangement in rabbits after implantation of a polypropylene mesh (PM) into the capsule defect. Methods: the study was performed on 50 rabbits weighing (694 ± 27) g. A capsule defect was formed on the right knee joint between the patellar ligament and the medial collateral ligament. In the experimental group (25 rabbits), the defect was repaired using PM, in the control group (25) — the edges of the defect were tightened and sutured with vicryl. A modified Vanderbilt University scale was used to assess the scarring process. Morphological analysis was performed. Results: no significant clinical differences in the state of the operated knee joint in the postoperative period were found between the groups. In the control group, from the 7th day after the surgery, the formation of dense connective tissue (scar) was observed. In animals of the experimental group, against the background of the formation of connective tissue around the PM, a significant thickening of the capsule and ligaments was observed at the points of contact with it. In 21 days after PM implantation, 51–75 % of its area showed ingrowth of connective tissue, after 45 — 75–100 %. After 2 months after the surgery, the relative area of dense connective tissue in the experiment was (68.12 ± 2.74) % versus (51.68 ± 4.22) % in the control.Conclusions: implantation of PM into the area of the knee joint capsule defect of rabbits between the patellar ligament and the medial collateral led to the formation of a larger volume of dense connective tissue at the final follow-up period (2 months). Ingrowth of connective tissue between cells and fibers of PM promotes the formation of a tight connection with the surrounding tissues, thereby strengthening area of traumatic injury.