Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol
Stephanie R. Filbay, Matthew Dowsett, Mohammad Chaker Jomaa, Jane Rooney, Rohan Sabharwal, Phil Lucas, Andrew Van Den Heever, J. Kazaglis, Justin Merlino, M. Moran, Maggie Allwright, D. Kuah, Ra Durie, Greg Roger, Mervyn J. Cross, Tom Cross
Abstract
Objective Investigate MRI evidence of anterior cruciate ligament (ACL) healing, patient-reported outcomes and knee laxity in patients with acute ACL rupture managed non-surgically with the Cross Bracing Protocol (CBP). Methods Eighty consecutive patients within 4 weeks of ACL rupture were managed with CBP (knee immobilisation at 90° flexion in brace for 4 weeks, followed by progressive increases in range-of-motion until brace removal at 12 weeks, and physiotherapist-supervised goal-oriented rehabilitation). MRIs (3 months and 6 months) were graded using the ACL OsteoArthritis Score (ACLOAS) by three radiologists. Mann-Whitney U tests compared Lysholm Scale and ACL quality of life (ACLQOL) scores evaluated at median (IQR) of 12 months (7–16 months) post-injury, and χ 2 tests compared knee laxity (3-month Lachman’s test and 6-month Pivot-shift test), and return-to-sport at 12 months between groups (ACLOAS grades 0–1 (continuous±thickened ligament and/or high intraligamentous signal) versus ACLOAS grades 2–3 (continuous but thinned/elongated or complete discontinuity)). Results Participants were aged 26±10 years at injury, 39% were female, 49% had concomitant meniscal injury. At 3 months, 90% (n=72) had evidence of ACL healing (ACLOAS grade 1: 50%; grade 2: 40%; grade 3: 10%). Participants with ACLOAS grade 1 reported better Lysholm Scale (median (IQR): 98 (94–100) vs 94 (85–100)) and ACLQOL (89 (76–96) vs 70 (64–82)) scores, compared with ACLOAS grades 2–3. More participants with ACLOAS grade 1 had normal 3-month knee laxity (100% vs 40%) and returned to pre-injury sport (92% vs 64%), compared with participants with an ACLOAS grades 2–3. Eleven patients (14%) re-injured their ACL. Conclusion After management of acute ACL rupture with the CBP, 90% of patients had evidence of healing on 3-month MRI (continuity of the ACL). More ACL healing on 3-month MRI was associated with better outcomes. Longer-term follow-up and clinical trials are needed to inform clinical practice.