Summary

A retrospective analysis of 84 lateral meniscus root ruptures treated with repair through separate bone tunnels or trough the tibial ACL-R tunnel in concomitant ACL-R and root repair

Abstract

Introduction.
A meniscus root rupture is a serious additional injury to an Anterior Cruciate Ligament (ACL) injury. However, specific treatment of this injury has been performed only in recent time. Several instruments have been developed to reattach the root to the bone in a separate tunnel in the tibia at the time of ACL reconstruction (ACL-R). The lateral meniscus posterior root is closely related to the tibial ACL tunnel in ACL-R. we wanted to assess if the fixation of the lateral posterior root rupture (LPRR) through the ACL tibial tunnel affected the results after ACL-R. Primary endpoint was re-rupture assessed by second look arthroscopy.

Method

Retrospective analysis of ACL-R done at the institution 2015-2021 with 2 years follow up completed. Comparison between LPRR with separate tunnel or through ACL tibial tunnel. Was assessed for re-rupture with re-arthroscopy due to persisting symptoms and suspected rupture on Magnet Resistance Tomography (MRT). Patient related knee function was assessed with Knee injury and Osteoarthritis Outcome Score including PASS, range of motion by goniometer, strength with Biodex.

Results

Of 1395 ACL-R between 2015-2021 108 (7.8%) patients with a posterior meniscus root rupture (PMRR) was identified. The mean patient age was 31 (SD 11) and 66 (62%) were males. For a majority the activity at injury was a pivoting sport (29% soccer and 7% downhill skiing). There were a mix of grafts used for the reconstruction with the majority 63 (58%) hamstring and Quadriceps second with 40 (37%) and Patella least frequently used 5 (5%) fitting the normal proportion in the clinic.
Of the meniscus root ruptures 84 (78%) was lateral (6.0% of all ACL-R). The pivoting activity similar in the lateral root ruptures, 32% soccer and 7% downhill skiing. A separate tunnel technique was used in 38 (45%) (group S) and the tibial ACL tunnel in 46 (55%) (group T) Mean age in these groups was similar 31 (SD 11) and graft types used 58% (grp S) and 57%(grp T) Hamstring 42 % (grp S) and 37% (grp T). There were 68% males in grp S and 57% in grp T. At the six months follow-up there were few ROM deficits in either group. Few patients had an LSI on Biodex testing above 90% in patients with a Quadriceps graft with no difference between the groups. Of the patients with hamstring graft more had gained an LSI>90% in grp S 86% compared to grp T with 44% (p=0.03). Knee injury and osteoarthritis outcome score (KOOS) was similar at 2 years after surgery. Failure of the meniscus was recorded in 2 patients (5.3%) in grp S and 4 patients (8.7%) with no statistical difference between the methods.

Discussion

The major finding was that the use of the ACL tibial tunnel seems to be a comparable method to fixation of a LPRR with a separate tunnel. However, there was a limited number of patients assessed in this study and the absolute numbers might indicate advantages with the use of a separate tunnel.