16/01/2023
⁉️Can the anterior cruciate ligament (ACL) heal?
❗️Key Points
1. There is exploratory evidence that there may be signs of ACL healing at 2 and 5 yrs after injury.
2. Participants with evidence of ACL healing appeared to have better Outcomes at 2 years, but not 5 yr follow ups, when compared to nonhealed, early, or delayed ACL replacement groups.
3. Spontaneous ACL healing may occur more frequently than previously thought.
🦵🏼2 Groups
Group 1: 62 - Early ACL Reconstruction (ACLR) (Surgery)
Group 2: 59 - Rehab with the option of delayed surgery (51% of patients in this delayed group had ACLR within 5 yrs.)
📖 Results
2-yr follow-up: 30% of participants in Group 2 had evidence of ACL healing on MRI. Of these, 24 /54 participants went on to have surgery.
Of the 30 remaining in the rehabilitation only group (Group 2), 53% had evidence of ACL healing at 2 yrs. At 5 yrs, 58% had evidence of ACL healing.
Participants with evidence of ACL healing reported better outcomes at 2 yrs over participants with non-healed ACL or those in the early or delayed ACLR Surgical groups.
However, at 5 yrs, all groups had similar outcomes.
⚠️Limitations
This study was a secondary analysis and was not powered (i.e. sufficient sample size) to answer the research question. The small sample size and wide confidence intervals indicates a lack of certainty in the conclusions and findings should be interpreted with caution.
This study was conducted in recreational athletes, and we are unable to generalize to elite athletes or patients in jobs that place high demand on their knees (e.g. firefighters).
🏋🏽♀️ Clinical Implications
While this study provides exploratory evidence that the ACL can heal spontaneously, it by no means replaces our current knowledge and management of ACL tears. However, it does shed light on the fact that patients will benefit from a period of rehabilitation first before deciding upon surgical or non-surgical management, and perhaps one of these benefits is potential healing of the ACL.
We still do not know who or what type of patients may lead to ACL healing and current trials are underway regarding bracing acute ACL tears to promote healing.
