Summary
Preoperatively, the ramp group showed increased anterior knee instability compared to the control group, but postoperative knee stability was comparable between the two groups, suggesting that ramp lesion repair may restore knee stability in ACL reconstruction, and ramp lesion repair may be recommended.
Abstract
Introduction
Previous studies have suggested that concomitant medial meniscus ramp lesions in anterior cruciate ligament (ACL) injuries are associated with preoperative knee instability. However, there is a lack of studies on the postoperative stability and outcomes. Therefore, the purpose of the present study was to invesitgate the impact of ramp lesion repair in primary ACL reconstruction on postoperative outcomes.
Methods
The present retrospective study included 132 patients who underwent primary ACL reconstruction using hamstring autograft, and second-look arthroscopy approximately one year postoperatively. At the time of primary ACL reconstruction, a definitive diagnosis was made regarding the presence of concomitant meniscal injuries. Ramp group consisted of patients with ramp lesions, while control group was defined as the patients without medial/lateral meniscal injuries. Preoperatively, under general anesthesia, anterior tibial translation (ATT) during the Lachman test and posterior tibial acceleration during the pivot-shift test were measured using an electromagnetic measurement system (EMS) as previously reported. The ATT was also measured using a KT arthrometer. The side-to-side difference (SSD) in ATT was calculated. These measurements were repeated about one year after the surgery under general anesthesia at the time of screw removal and second look arthroscopy. An unpaired t-test was used to compare SSD in ATT, tibial acceleration, IKDC subjective knee form (IKDC-SKF) between the Control and the Ramp groups at pre- and post-ACL reconstruction respectively (P < 0.05).
Results
The ramp group consisted of 26 patients (age: 22 ± 7 years, 12 male, 14 female), and control group consisted of 44 patients (age: 26 ± 13 years, 23 male, 21 female) after excluding those with other medial/lateral meniscus injuries. All ramp lesions were repaired and healing was confirmed via second-look arthroscopy. Preoperatively, the SSD in ATT during the Lachman test was significantly larger in the ramp group (6.1 ± 3.5 mm vs 4.0 ± 4.5 mm, P = 0.04). However, no significant difference was observed between two groups postoperatively (0.2 ± 3.5 mm vs 1.4 ± 4.1 mm, P = 0.22). Regarding the pivot-shift test, no significant difference was found in preoperative tibial acceleration (1.7 ± 1.0 m/s² vs 1.7 ± 0.7 m/s², P = 0.94), but significant difference was observed postoperatively (1.1 ± 0.5 m/s² vs 1.3 ± 0.6 m/s², P =0.02). No significant differences were observed in terms of SSD in ATT using the KT and IKDC-SKF scores preoperatively and postoperatively.
Conclusion
Preoperatively, the ramp group showed increased anterior knee instability compared to the control group, but postoperative knee stability was comparable between the two groups. The findings suggest that ramp lesion repair may restore knee stability in ACL reconstruction, and ramp lesion repair may be recommended.