Figure. Sagittal MRI shows a proximal anterior cruciate ligament rupture.
A 14-year-old adolescent presents with left knee pain after a noncontact twisting injury during a soccer game 2 days ago. She was making a cutting maneuver and the knee buckled. She felt a pop and was unable to bear weight on the knee after the injury. On physical examination, she has a moderate knee effusion with a positive Lachman test. Sagittal magnetic resonance imaging (Figure) shows a proximal anterior cruciate ligament (ACL) rupture. The patient’s mother mentioned she heard some patients are having ACL repairs instead of reconstruction.
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Anterior cruciate ligament (ACL) reconstruction is the gold standard treatment option for patients who sustain an ACL tear. The ACL has a poor blood supply and ruptures are unlikely to heal with the same stability as its original form. This is why ACL repair options have failed in the past. The ACL fails to form a provisional scaffold between the 2 torn ends of the ACL, which is critical for wound site healing.1,2
The knee joint is lubricated by a continuous flow of synovial fluid that is thought to inhibit ACL healing by getting in-between the torn ends preventing healing tissue from forming. Unlike the ACL, the extra-articular medial collateral ligament (MCL) forms a scaffold between torn ends resulting in high rates of healing.1,2
Recent studies have started to show primarily ACL repair in select patients may be as effective as ACL reconstruction. The patient’s age, activity level, and location of the tear are all factors in determining if a patient is a repair candidate. Current data shows that repairs are more likely to fail in patients less than 18 years compared to patients more than 30 years. Also, patients who are active, particularly in running and cutting sports, are at a much higher risk of failure and repair should be avoided in these patients. Proximal ACL tears seem to be more amenable to repair than midsubstance and distal tears.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopaedics for Physician Assistants.
1. Murray MM. Current status and potential of primary ACL repair. Clin Sports Med. 2009;28(1):51-61. doi:10.1016/j.csm.2008.08.005
2. Gee MSM, Peterson DR, Zhou ML, Bottoni CR. Anterior cruciate ligament repair: historical perspective, indications, techniques, and outcomes. J Am Acad Orthop Surg. 2020;28(23):963-971. doi:10.5435/JAAOS-D-20-000771