Summary
The additional massive notchplasty to fully dilate the inner wall of the lateral femoral condyle as well as the intercondylar outlet is effective in case of a revision surgery.
Abstract
Introduction
Previous studies showed variations in femoral tunnel location led to altered anterior tibial translation, while a more vertical graft increased the passive anterior and rotational laxities of the knee, and resulted in fixed anterior tibial subluxation. Thus, in cases of revision anterior cruciate ligament (ACL) reconstruction, graft impingement to intercondylar notch after ACL reconstruction is a problem due to anterior tibial translation. The notchplasy during ACL reconstruction may have possibility to avoid the graft damage after the surgery. The purpose of this study was to clarify the effect of notchplasty during revision ACL reconstruction on clinical outcomes. Our hypothesis is massive notchplasty is quite effective on protect graft tear in revision ACL reconstruction.
Methods
Seventeen patients underwent revision ACL reconstruction with an ipsilateral bone-patellar tendon-bone autograft or an ipsilateral bone-quadriceps tendon autograft between January 2019 and May 2021 and were followed up for more than 2 years. There were twelve males and five females with mean age of 27. The ACL reconstruction was performed with the anatomic rectangular tunnel technique, in which rectangular bone tunnels were created within the anatomical tibial and femoral ACL footprints. In eight cases with primary non-anatomic ACL reconstruction, massive notchplasty to fully dilate the inner wall of the lateral femoral condyle as well as the intercondylar outlet was added. The mean duration between the primary and the revision surgery was 110 months. Then, the number of postoperative re-tears, tibial positions related to femur using MRI at 6 months postoperatively, and knee stability at 2 years postoperatively with KT Knee Arthrometer were evaluated. Statistical analysis was performed using Mann-Whitney’s U test to compare the result between cases with and without notchplasty.
Results
In nine cases without notchplasty, two patients showed instability without an obvious injury mechanism within 6 months after surgery, while no instability was observed in the 8 cases with notchplasty. The tibia position in relation to the femur at 6 months was 2.3 ± 1.2 mm for medial and 4.0 ± 1.9 mm for lateral in the cases without notchplasty, and 1.3 ± 0.9 mm for medial and 3.1 ± 2.5 mm for lateral in the cases with notchplasty, indicating a 1 mm posterior shift in both sides with a significant difference. The side-to-side difference at 2-year follow-up was 0.0±0.6mm in the cases without notchplasty, excluding the two cases showing instability, and 0.0±0.7mm in the cases with notchplasty.
Conclusion
Although the postoperative stability of ACL reconstruction using the anatomic rectangular tunnel technique were excellent, the higher rate of graft failure was observed in the cases without massive notchplasty. Thus, the additional massive notchplasty would be preferable to be performed in case of a revision surgery, regardless of the tunnel locations at the primary ACL reconstruction.