The Risk of Iatrogenic Peroneal Nerve Injury in All-Inside Lateral Meniscus Repair Using a Vertical Stitch: A Cadaveric Study

Background: An all-inside lateral meniscus repair in relation to the popliteus tendon is still challenging in arthroscopic surgery, with a high rate of failure as the joint capsule is quite thin, often leading to insecure meniscal repairs. To reduce the rate of failure, vertical suturing has been suggested, but there is still a chance of iatrogenic peroneal nerve injury because the peroneal nerve is located close to the joint capsule and the popliteus tendon. Purpose: To evaluate the risk of iatrogenic peroneal nerve injury in all-inside meniscal repair with a vertical stitch, comparing between 90° and 120° of knee flexion, using full-body fresh-frozen cadavers. Study Design: Descriptive laboratory study. Methods: The study used 15 cadavers, 8 male and 7 female. A straight all-inside meniscal repair device with a 20-mm penetration depth was used for the meniscal repairs, randomized into repairs of the lateral meniscus penetrating the meniscus at the peripheral and inner one-third of the medial and lateral borders of the popliteus tendon in 2 knee positions. The shortest distance from the tip to the peroneal nerve was measured, and the measurements were compared between repairs in 2 knee positions. Results: In simulated cadaveric repair, there was a chance of iatrogenic peroneal nerve injury with vertical stitch deployment at the inner one-third of the medial border of the popliteus tendon, with injury incidences of 10% and 6.7% in 90° and 120° of knee flexion, respectively. The mean shortest distances related to the medial borders of the popliteus tendon in 90° of knee flexion were statistically significantly shorter than those with the knee in 120° of flexion. Conclusion: Vertical stitching at the lateral border of the popliteus tendon maintained a safe distance from the peroneal nerve. However, a small risk of iatrogenic injury remained at the inner one-third of the medial border. Clinical Relevance: The surgeon should avoid penetrating the lateral meniscus at the inner one-third of the medial border of the popliteus tendon, but if a repair must be done in this area, the surgeon should position the knee at 120° of knee flexion.