Abstract
Objectives:
Short-term follow-up of anterior cruciate ligament (ACL) primary repair (ACLPR) presented increased failure risk (37%) in patients ≤21 years of age (y/o), however low rates in patients >21 y/o (3.5%). Mid- and long-term clinical evidence for contemporary anterior cruciate ligament primary repair (ACLPR) is lacking, whereas outcomes of historical ACL repair were shown to deteriorate at midterm follow-up after initial good short-term outcomes. This study evaluates age-differentiated survival rates of ACLPR at 5-year FU to assess whether the previously presented rates at 2-year FU can be maintained at 5-year FU.
Methods:
The first 113 consecutive patients with proximal ACL tears undergoing ACLPR by a single surgeon, from 04/2008 to 09/2017, were prospectively followed up. Indication for ACLPR was determined if a proximal type I or II tear and good to excellent tissue quality was present. Failure and re-operation rates, patient reported outcome measurements (PROMs) (IKDC score, Lysholm score, Forgotten Joint score, ACL-RSI score, and Tegner Activity Scale Difference) and instrumented anterior-tibial translation side-to-side difference (ATT-SSD) were recorded at minimum 5-year FU.
Results:
A total of 96 patients (85%) with a mean final FU of 7.2 ±2.3 (5.0 – 12.8) years were evaluated. Ipsilateral reinjury rates for patients ≤21 y/o, from 2- to 5-year FU, remained stable (40.0%) with no additional failure recorded. Six additional re-injuries were detected in patients >21 y/o, leading to a failure rate of 9.8% at 5-year FU. Mean time to failure following surgery was 17 ±11 months in patients ≤21 y/o versus 26 ±16 months in patients >21 y/o. Re-operation rates for patients ≤21- and >21 y/o were 0.0% and 4.0% respectively. PROMs showed no significant differences as compared to outcomes at 2-year FU (p <.001) and 5-year ATT-SSD was 0.75 ±1.2 mm.
Conclusions:
ACLPR is correlated with a high risk of early failure (40.0% at 17 ±11 months) in patients < 21 y/o, however no additional subsequent re-injuries were reported at minimum final 5-year FU. In contrast, patients >21 y/o demonstrate low failure rates at 2- (3.5%) and 5-year FU (9.8%).