Description
Objectives
The ramp lesion of medial meniscus in anterior cruciate ligament (ACL) injury has drawn attention recently, but the association between ramp lesion and preoperative knee laxity remains unclear. The objective of the present study was to evaluate the contribution of ramp lesion to preoperative knee antero-posterior (AP) laxity and antero-lateral rotatory instability (ALRI). It was hypothesized that with concomitant ramp lesion, the AP laxity would be greater compared to the isolated ACL injury.
Methods
206 patients (mean age at the surgery: 27 years, 107 males / 99 females) who underwent ACL reconstruction from 2014 to 2022 were retrospectively enrolled in the study. The diagnoses of the meniscal injuries were made by arthroscopic inspections, and the incidence of ramp lesion was identified. The patients with ramp lesion and no other meniscal injury were allocated to ‘ramp group’, and the patients without any meniscal injury were allocated to ‘noninjury group’. Prior to ACL reconstruction under general anesthesia, the electromagnetic measurement system (EMS) was used to measure the side-to-side difference (SSD) in anterior tibial translation (ATT) during Lachman test (mm) and posterior tibial acceleration (PTA) (m/s2) during the pivot-shift test. KT-2000 was also used to evaluate SSD in ATT (mm). The data were statistically compared between two groups using unpaired student t-test. All the patients were given the informed consent and the present study was approved by the Institutional Review Board.
Results
Ramp lesions were observed in 30 patients (14.7%), in which lateral meniscal injuries were seen in 13 patients. 17 patients were in ‘ramp group’ and 77 patients were in ‘noninjury group’, and there were no statistical differences with regard to background demographics. ATT-SSD measured by EMS was significantly greater in ‘ramp group’ (9.1±6.6 mm vs. 6.2±4.4mm, p=0.037). However, KT2000-SSD (5.5±2.5mm vs. 5.1±2.2mm, p=0.55) and PTA (1.3±0.9 m/s2 vs. 1.5±0.9 m/s2, p=0.65) were not significantly different.
Conclusions
Concomitant ramp lesion contributed to greater ATT during the Lachman test, but did not have significant impact on ATT in KT-2000 and ALRI. Concomitant ramp lesion in ACL injury may contribute to greater anterior knee laxity evaluated by Lachman test.
