Is the popliteal tendon an adequate anchor for lateral meniscus repairs? A cadaveric study

OBJECTIVES: Arthroscopic lateral meniscus repairs are performed in the Cabot test position. Anchor fixation to the popliteal tendon is often the primary anchor. Our hypothesis was that the mobility of the popliteal tendon in flexion-extension leads to significant stress or even early loosening of sutures. METHODS: Twenty-two fresh adult human cadaveric knees were used. A vertical stitch was made arthroscopically with "all-internal" implants in the popliteal tendon through the lateral meniscus. The knee was taken from the Cabot test position and placed in full extension at the end of the procedure. The condition of the suture was then assessed under arthroscopy. Sutures were considered to have failed if they had sufficient slack to pass the arthroscope through the hiatus, if the knot had passed through the meniscus, or if the thread was broken. RESULTS: 59.9% (n = 9) of the stitches were tight and 40.1% were loose (n = 9). 18.2% (n = 4) were relaxed, for 18.2% (n = 4) the knot had passed through the meniscus, and 4.5% (n = 1) had a break in the suture. CONCLUSION: Sutures placed between the lateral meniscus and the popliteal tendon failed after a single cycle of knee flexion and extension in 40% of the cases. A single stitch in this manner is not an adequate means of repairing lateral meniscal injuries.