Unstable RAMP Lesions of the Medial Meniscus in ACL-Deficient Knee: Comparing the Outcomes of Outside-in versus All-inside Surgical Repair - a Retrospective Study

PURPOSE OF THE STUDY We present the results of the retrospective study comparing the clinical outcomes of outside-in versus all-inside suture techniques of unstable RAMP lesions (RL) of the medial meniscus in patients with simultaneous ACL lesion with a minimum two-year follow-up. MATERIAL AND METHODS The retrospective evaluation covered two groups of patients who underwent the arthroscopic repair of unstable RL in combination with anterior cruciate ligament reconstruction (ACLR). Group 1 included 42 patients (28 men/24 women). Group 2 consisted of 36 patients (21 men/15 women). In Group 1, RL suture repair using the outside-in technique by posteromedial approach with absorbable PDS suture was performed, while in Group 2 the all-inside technique of RL suture via the standard anteromedial portal was applied using the Fast-Fix system (Smith Nephew, USA). The evaluation was done preoperatively and postoperatively with the mean follow-up of 27.9 months in Group 1 and 30.1 months in Group 2. The patients were assessed using the subjective IKDC score and the side-to-side difference (SSD) in ventral laxity was measured by Genourob (GNRB) laximeter at the applied pressure of 134 N and 250 N. Moreover, the failure rate of RAMP lesion repair, ACL graft, necessity of secondary partial meniscectomy and return to pre-injury level of sport were analysed. RESULTS The median IKDC score increased in Group 1 from 56 points preoperatively to 92 points postoperatively and in Group 2 from 58 points preoperatively to 90 points postoperatively (p>0.05). The median value of SSD in ventral laxity of the knee measured by the GNRB laximeter at the applied pressure of 134 N in Group 1 was 5.6 mm preoperatively and 1.9 mm postoperatively and in Group 2 it was 5.9 mm preoperatively and 2.3 mm postoperatively. At the pressure of 250 N, the median value in Group 1 was 7.9 mm preoperatively and 2.7 mm postoperatively and in Group 2 it was 8.1 mm preoperatively and 3.2 mm postoperatively. When comparing the SSD of the groups postoperatively, no statistically significant difference was found (p>0.05). Revision arthroscopy was performed in 8 patients. In 1 patient (2.4 %) in Group 1 and in 4 patients (11.1%) in Group 2 a rerupture of the RL of the meniscus occurred and partial meniscectomy was performed. In Group 2, statistically significant higher occurrence of the RL suture failure (p 0.05). 31 evaluated patients (73.8%) from Group 1 and 24 patients (66.7%) from Group 2 (p>0.05) returned to the pre-injury level of sports activities. DISCUSSION When comparing the outcomes of individual techniques of the RL repair published in recent literature with our conclusions, we may state that the results of subjective as well as objective criteria achieved were similar to those reported by other authors worldwide. No study has so far been published which would compare the outcomes of the by us presented two surgical techniques of the RL suture in an ACL-deficient knee with a minimum follow-up of 24 months. CONCLUSIONS Both the surgical techniques of unstable RL repair in combination with the ACLR using a tendon graft result in a statistically significant improvement of clinical outcomes postoperatively. In Group 2, with the all-inside RL repair, a statistically significant higher failure rate of RL repair was confirmed as well as the need to perform secondary partial meniscectomy compared to Group 1. Key words: RAMP lesion, ACL-deficient knee, unstable medial meniscus lesion, repair of meniscus, all-inside technique, posteromedial technique, ACL reconstruction.