Summary
At median 11-year follow-up, no cases of clinically relevant radiographic osteoarthritis as well as excellent clinical outcomes including high patient reported outcome measures and preserved knee stability were observed in patients that underwent selective, arthroscopic anterior cruciate ligament primary repair.
Abstract
Introduction
The current gold standard for addressing knee instability after anterior cruciate ligament (ACL) rupture is ACL reconstruction (ACLR) using autograft; however, despite its clinical benefits, the incidence of post-traumatic osteoarthritis (PTOA) (Kellgren & Lawrence (KL) grade 2 or higher) after ACLR remains considerable. It has been suggested that ACLR initiates a “second inflammatory hit” associated with an acute increase in cartilage degenerative markers. Unlike historical open repair techniques that demonstrated high failure rates, arthroscopic ACL primary repair (ACLPR), with its less invasive nature, may potentially reduce the incidence of PTOA after ACL injury.
Purpose
This study builds upon findings reported at the 2014 ACL Study Group Meeting and aimed to assess the long-term incidence of PTOA and clinical outcomes at a minimum of 10-years following selective, arthroscopic ACL primary repair (ACLPR). It was hypothesized that the selective application of, and the less invasive nature of ACLPR would result in both excellent clinical outcomes and a lower incidence of significant PTOA as compared to the commonly reported 21% rate following ACLR.
Methods
Prospective data was collected on consecutive patients with proximal, modified Sherman type I ACL tears who underwent arthroscopic ACLPR with dual suture anchor fixation between 2008 and 2014. Inclusion required a minimum of 10-year follow-up data. Standardized radiographs of both knees were obtained preoperatively and at 10-year follow-up to assess PTOA as determined by KL and minimal joint space width (JSW). Secondary outcomes comprised repair failure and reoperation rates, anterior tibial translation side-to-side difference (ATT SSD), International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Single Assessment Numeric Evaluation (SANE), Cincinnati Knee Rating System (Cincinnati), Forgotten Joint Score (FJS-12), Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) score, Tegner Activity Scale, and Patient Acceptable Symptom State (PASS).
Results
Outcomes for 16 out of 18 patients (median: 40 years, 79% male) were recorded at final follow-up (median (IQR), 11 (10-12) years). Radiographic analysis revealed 46% KL grade 0 and 55% grade 1; 0% demonstrated KL 2 or higher. KL grade at 10-years was similar to preoperative KL grade in the ipsilateral (p=0.39) and 10-years contralateral knee (p=0.84). Furthermore, JSW was not significantly different in all compartments (all p>0.05). Two patients (12.5%) reported a traumatic ipsilateral ACL reinjury (one non-compliant, one slip on ice), both treated non-op. Two patients (12.5%) had to undergo reoperation, one for meniscal repair (3.5 years post-op, power lifter, deep squat) and one for contralateral ACLPR (10.5 years post-op, basketball). ATT SSD was 0.9±1.4mm while median IKDC was 95 (93-99), Lysholm: 96 (90-100), SANE: 90 (88-100), Cincinnati: 97 (96-100), FJS-12: 96 (90-100), ACLR-RSI: 90 (68-100), equal pre- to postoperative Tegner (p=0.25), and PASS was achieved in 92-100%.
Conclusion
Although, this study has a limited sample size, common with novel procedures, it represents the longest follow-up of modern-day, selective, arthroscopic ACLPR outcomes in the literature. At 10 to 12 years, no cases of clinically relevant PTOA, as well as excellent clinical outcomes including high patient reported outcome measures and preserved objective knee stability were observed.