At ten year follow-up of an RCT there is no clinical benefit with remnant sparing ACLR compared with remnant debridement ACLR although re-operations were higher and time to graft rupture were longer in the remnant spared group.
Delayed ligamentization following anterior cruciate ligament reconstruction (ACLR) may result in reduced graft stiffness and strength, and an increased risk of secondary re-tear. Remnant sparing ACLR may accelerate ligamentization and proprioceptive function, theoretically reducing re-injury risk.
A lower graft failure rate and higher perceived functioning knee would exist at 10 years in those undergoing ACLR with remnant preservation (RP), versus remnant debridement (RD).
Study Design: Prospective randomized controlled trial (RCT).
A prospective RCT allocated 49 patients to ACLR with a hamstrings autograft together with a RD (n=25) or RP (n=24) procedure, of which 86% were clinically evaluated at 10 years (22 RD, 22 RP). A detailed chart review and patient phone consultation was undertaken with all patients at 10 years to evaluate the incidence (and timing) of subsequent re-tear and/or contralateral ACL tear, as well as other knee injuries/surgeries, the patient’s ability to perform full work/sport duties and their perceived knee function using a numerical rating scale (NRS). Independent t-tests were used to compare continuous outcomes, and Chi-square tests (and Fisher’s exact test when appropriate) were used to compare categorical outcomes.
No differences existed between groups (p>0.05) in descriptive variables. There were 2 graft ruptures (10.0%) in the RP group and 3 (13.6%) in the RD group, with an earlier mean time to graft failure in the RD group (RD 7.7 ± 4.5 months, RP 49.5 ± 17.7 months), albeit the size of this sub-sample was too small for statistical comparison. There was a significantly higher number of patients requiring =1 additional ipsilateral knee surgery in the RP group (RP=10, RD=4, p=0.048). At 10 years, 16 (72.7%) and 15 (75.0%) patients in the RD and RP ACLR groups, respectively, were unrestricted in work/sport duties (p=0.867). There were no group differences in the functional NRS ratings (p=0.537).
No long term clinical benefit of RP ACLR could be determined by this study with similar re-tear incidence and perceived knee function, though a higher number of re-operations were observed in RP patients with a tendency toward later time to re-tear. Time to graft rupture may be a useful measure of graft ligamentization
Keywords: anterior cruciate ligament reconstruction, remnant sparing, remnant preservation, clinical outcomes, knee function, re-injury.