Delaying ACL reconstruction and treating with exercise therapy alone may alter prognostic factors for 5-year outcome: an exploratory analysis of the KANON trial

Abstract

AimIdentify injury-related, patient-reported and treatment-related prognostic factors for 5-year outcomes in acutely ACL-ruptured individuals managed with early reconstruction plus exercise therapy, exercise therapy plus delayed reconstruction or exercise therapy alone.MethodsExploratory analysis of the Knee Anterior Cruciate Ligament, Nonsurgical versus Surgical Treatment (KANON) trial (ISRCTN84752559). Relationships between prognostic factors (baseline cartilage, meniscus and osteochondral damage, baseline extension deficit, baseline patient-reported outcomes, number of rehabilitation visits, graft/contralateral ACL rupture, non-ACL surgery and ACL treatment strategy) and 5-year Knee Injury and Osteoarthritis Outcome Score (KOOS) pain, symptoms, sport/recreation and quality of life (QOL) scores were explored using multivariable linear regression. Estimates were adjusted for sex, age, body mass index, preinjury activity level, education and smoking.ResultsFor all participants (n=118), graft/contralateral ACL rupture, non-ACL surgery and worse baseline 36-item Short-Form Mental Component Scores were associated with worse outcomes. Treatment with exercise therapy alone was a prognostic factor for less knee symptoms compared with early reconstruction plus exercise therapy (regression coefficient 10.1, 95% CI 2.3 to 17.9). Baseline meniscus lesion was associated with worse sport/recreation function (−14.4, 95% CI −27.6 to –1.3) and osteochondral lesions were associated with worse QOL (−12.3, 95% CI −24.3 to –0.4) following early reconstruction plus exercise therapy. In the same group, undergoing additional non-ACL surgery and worse baseline KOOS scores were prognostic for worse outcome on all KOOS subscales. Following delayed reconstruction, baseline meniscus damage was a prognostic factor for less pain (14.3, 95% CI 0.7 to 27.9). Following exercise therapy alone, undergoing non-ACL surgery was prognostic for worse pain.ConclusionsTreatment-dependent differences in prognostic factors for 5-year outcomes may support individualised treatment after acute ACL rupture in young active individuals.Trial registration numberCurrent Controlled Trials ISRCTN84752559.

Editorial Commentary: Fifty Is the New 30? Do Patients in Their 50s Deserve an Anterior Cruciate Ligament Reconstruction?

“…The KANON trial suggested that patients undergoing rehabilitation or delayed surgery had significantly better outcomes at 5 years compared with patients who had ACL reconstruction surgery within 10 weeks of injury. 2,3 However, these conclusions have to be viewed with caution, as many patients remain symptomatic and may opt for late reconstruction surgery. 4 In contrast, several studies demonstrated that early surgery resulted in better clinical outcomes with earlier return to sports.…”

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“…The time interval from ACL injury to ACLR may be less important as the condition of the knee at the time of surgery (Lattermann et al, 2018). Better pre-operative knee function is associated with fewer post-surgical complications and greater post-operative knee function (Beynnon et al, 2005;Filbay et al, 2017;. Therefore, treatment following ACL injury should involve physical rehabilitation to optimise functional ability before any decisions regarding surgical intervention are made (Eitzen et al, 2010;Thoma et al, 2019).…”

Why all the fuss about paediatric ACL rupture: isn’t the meniscus much more important?

“…Lately, a great deal of attention has been placed on the degenerative meniscal tear and the role of arthroscopic treatment 8. Let us stop being so concerned about meniscal tears in middle-aged people.…”