Does anterior cruciate ligament reconstruction prevent development of meniscal damage? Results from a secondary analysis of a randomized controlled trial.

Snoeker BAM, Roemer FW, Turkiewicz A, et al. Br J Sports Med. 2019. [Epub Ahead of Print].

https://bjsm.bmj.com/content/early/2019/10/25/bjsports-2019-101125.long

Take-Home Message

A person who received an early anterior cruciate ligament reconstruction was less likely to have medial meniscal damage at 5 years after surgery than someone who received an option for a delayed reconstruction.

Summary

Anterior cruciate ligament (ACL) rupture is a common injury in sport that can compromise long-term joint health and greatly affect an athlete’s short- and long-term quality of life. One critical factor with respect to the long-term joint health is the status of the meniscus. We know from observational studies that a delay in ACL reconstruction may increase the risk of meniscal damage over time; but, there is no data from randomized clinical trials. Therefore, Snoeker and colleagues used data from the KANON study, which is a randomized controlled trial, to determine if new or worsening meniscal damage over 5 years after an ACL injury differed between people receiving either an early ACL reconstruction or an optional delayed ACL reconstruction. The KANON study included 121 active adults who underwent a knee MRI at both baseline and 5-year follow-up appointments. For the current study, these MRIs were obtained and read to observe meniscal damage at the follow-up appointment. One radiologist used The Anterior Cruciate Ligament Osteoarthritis Score (ACLOAS) to grade meniscal damage. The authors evaluated group differences in new or worsening meniscal damage or the severity of meniscal damage.

Before treatment, the early ACL reconstruction group had more lateral meniscal damage (25% vs 7%) than the optional delayed group; however the frequency of medial meniscal damage was similar (15% in each group). After 5 years, 45% participants in the early reconstruction group showed new or worsening meniscal damage compared to 53% in the delayed reconstruction group. Meniscal severity scores were worse in the optional delayed treatment group than in the early reconstruction group. These findings were primarily driven by new or worsening meniscal damage in the medial compartment.

Viewpoints

Overall, the authors found strong evidence in a randomized clinical trial to support prior findings that an early ACL reconstruction may help protect the long-term status of the meniscus. While the cause of this is still unknown, ACL reconstruction is often recommended to try to restore the biomechanics of the knee to preinjury levels. While other biomechanical research has suggested that the mechanics never truly reach preinjury levels, perhaps the reconstruction restores these mechanics enough to protect the medial meniscus. It will be important to better understand how these findings relate to prior work from this clinical trial where the authors found no differences in the presence of osteoarthritis at 5 years between groups and possibly a trend for the early reconstruction group having more osteoarthritis (33% vs 18%). Based on the meniscal findings, we would have expected the early reconstruction group to have less osteoarthritis at 5 years. May be some of the increased osteoarthritis is related to the early reconstruction group having more lateral meniscal damage at baseline. These findings highlight the need for more clinical trials to help us understand the long-term consequences of our treatment decisions after an ACL injury. In the meantime, we should educate patients that an early ACL reconstruction may protect the medial meniscus; however, it may not offer superior clinical outcomes (e.g., reduced chance of osteoarthritis, better patient-reported outcomes) than opting for a choice to have a delayed ACL reconstruction.

Questions for Discussion

Have you discussed with a patient the pros and cons of opting for an early ACL reconstruction or opting to try conservative care before deciding on an ACL reconstruction? What do you tell the patient?

Written by: Kyle Harris

Reviewed by: Jeffrey Driban

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