Healing Status of Meniscal Ramp Lesion Affects Anterior Knee Stability After ACL Reconstruction

Abstract

Background: Although the biomechanical importance of the ramp lesion in the anterior cruciate ligament (ACL)–deficient knee has been demonstrated, there is no clear consensus on the appropriate treatment for ramp lesions during ACL reconstruction. Purpose: To compare the postoperative outcomes for ramp lesions between patients treated with all-inside repair through the posteromedial portal and those whose ramp lesions were left in situ without repair during ACL reconstruction. We also determined whether ramp lesion healing status affected postoperative knee stability. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 57 patients who underwent anatomic double-bundle ACL reconstruction between August 2011 and December 2017 had attendant ramp lesions. Of these, 25 ramp lesions that were considered stable were left in situ without repair (Nonrepaired group), and 25 ramp lesions, including 21 stable and 4 unstable lesions, were treated using all-inside repair through the posteromedial portal (Repaired group). We evaluated the side-to-side difference (SSD) in anterior tibial translation on stress radiographs and rotational stability by using the pivot-shift test 2 years after surgery, and healing status of the ramp lesions was evaluated on 3.0-T magnetic resonance imaging (MRI) scans 1 year after surgery. Results: The mean SSDs in anterior translation were 2.4 ± 1.6 mm for the Nonrepaired group and 1.9 ± 1.6 mm for the Repaired group, with no significant differences. The positive ratios on the pivot-shift test were not significantly different between groups. Healing rates of ramp lesions on MRI scans showed a significant difference between the Nonrepaired group (60%) and the Repaired group (100%) ( P = .001). The mean SSDs for knees in which the ramp lesion had healed as shown on MRI scans and those in which it had not healed were 1.9 ± 1.6 mm and 3.2 ± 1.1 mm, respectively, which was a significant difference ( P = .02). Conclusion: Healing rates of ramp lesions were significantly better in the Repaired group than in the Nonrepaired group, although postoperative knee stability was not significantly different between groups. Anterior laxity in the knees in which the ramp lesion was unhealed was significantly greater compared with the knees in which the ramp lesion healed. All-inside repair through the posteromedial portal was a reliable surgical procedure to heal ramp lesions.

Editorial Commentary: Ramp Lesion: The Eye Sees Only What the Mind Is Prepared to Comprehend

“…29 It is our opinion that if a posteromedial portal is being created for abrasion and trephination, then it is logical to also repair the ramp lesion. This view is supported by the recent study by Hatayama et al, 30 who compared the postoperative outcomes for ramp lesions between patients treated with all-inside repair through the posteromedial portal and those whose ramp lesions were left in situ without repair during ACL reconstruction. The authors found that healing rates of ramp lesions were significantly better in the repaired group than in the non-repaired group.…”

“…They also found that anterior laxity was significantly greater in the knees with unhealed ramp lesions compared with the knees in which the ramp lesions had healed. 30 DePhillipo et al 24 have shown that patients with combined ACL tear and ramp lesions have increased preoperative knee anteroposterior and rotational knee laxity, as demonstrated by grade 3 Lachman (44% vs 6%) and pivotshift (38% vs 12%) tests when compared with ACL tear group without ramp lesion (P .005 for both). Thus, it makes more sense to repair the ramp lesion to restore the physiological knee stability and kinematics.…”

Medial Meniscal Ramp Lesion Repair Through Anterior Portals Using a Medial Collateral Ligament Pie-Crusting Technique

“… 5 Unrepaired ramp lesions can cause failure of ACL reconstruction, and acute rupture or chronic deficiency of the ACL can also cause ramp lesions owing to anteroposterior and rotational laxity. 5 , 9 , 10 , 11 , 12 Thus, unstable ramp lesions need to be repaired to ensure successful ACL repair. 5 , 13 However, unlike other meniscal injuries, ramp lesions can easily be misdiagnosed or overlooked.…”

Ramp lesion of the medial meniscus

“… 18 Various treatments of MRL exist, but the most definite and frequently applied is lesion repair. 19 …”

“…To conclude it all, patients who underwent MRL repair show significantly higher subjective scores, healing rates and significantly lower anterior laxity than those who did not. 19 Thus, surgical treatment should be advocated in all unstable lesions. 43 …”