Summary
Two-year post operative quantitative and qualitative MRI analysis revealed no statistically significant differences in cartilage health observed in the patellofemoral joint between patients who underwent primary ACLR with or without LET.
Abstract
Introduction
Anterior cruciate ligament reconstruction combined with lateral extraarticular tenodesis (LET) has shown to reduce graft failure rate. However, there is concern whether intervention by LET may cause increase contact pressure in the patellofemoral joint (PFJ) leading to cartilage injury. Therefore, the current study will evaluate PFJ cartilage status for patients that have undergone ACLR with LET by analyzing magnetic resonance imaging (MRI) quantitatively and qualitatively and compare with patients with ACLR without LET. We hypothesized that there will be no difference in cartilage injury analyzed by MRI between group with and without LET at two-year post-operative.
Methods
A subset of patients from the STABILITY 1 randomized control trial were included. All patients underwent primary ACLR with a hamstring autograft. The patients were randomized either to receive a combined LET procedure or not. Cartilage injury in the PFJ between ACLR alone group and ACLR and LET group were assessed quantitatively by quantitative MRI (qMRI) and qualitatively by ACL osteoarthritis score of post-operative 2 year MRI for surgical and contralateral non-surgical knees. Objective function outcomes (range of motion (ROM), hop test, and strength test) and patient reported outcome measures (ACL Quality of Life Questionnaire (ACLQOL), Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, lower extremity functional scale (LEFS), P4, Marx Activity Rating Scale, 12 item short form survey (SF-12)) were evaluated.
ANCOVA was used to determine the adjusted mean difference in T1rho and T2 relaxation times between groups for each compartment in the patella and trochlea. Adjusted mean T1 rho and T2 relaxation times and standard errors (SE) were provided for each compartment and group, along with associated p-values. We used Spearman’s rho to assess the correlation between relaxation times within each compartment and patient-reported and functional outcomes at two-years postoperative. Statistical significance was set at P = 0.05.
Results
92 patients (43 patients in ACLR group and 49 patients in ACLR and LET group) were included in the study. The mean and SE values for qMRI for adjusted T1 rho relaxation times (milliseconds) in the order of medial (MP), central (CP), and lateral patella (LP), and medial (MT), central (CT), and lateral trochlea (LT), ACLR vs ACLR and LET, (MP: 47.8(0.8) vs 47.3(0.7), CP: 45.5(0.7) vs 44.1(0.7), LP: 48.2(0.9) vs 47.3(0.8), MT: 54.7(1.2) vs 56.4(1.1), CT: 53.3(0.7) vs 53.1(0.7), LT: 5.9(1.0) vs 53.9(0.9)), and adjusted T2 relaxation times similarly, (MP: 42.2(0.8) vs 43.2(0.8), CP: 42.5(0.7) vs 42.7(0.6), LP: 43.5(0.8) vs 43.0(0.7),MT: 50.9(0.7) vs 50.9(0.6), CT: 51.1(0.8) vs 52.0(0.7), LT: 52.1(0.7) vs 52.6(0.6)) did not have any significant difference in between the two groups. Significant difference in ACLOAS scores and all objective functional outcomes and PROMs were not identified.
Conclusion
There was no difference in cartilage status in the patellofemoral joint between knees performed primary ACLR with hamstring tendon autograft with or without LET at 2 years post-operative follow-up assessed by MRI.