Among patients randomized to the optional-delayed ACL-reconstruction group, 30 (51%) opted for an ACL reconstruction. The treatment groups had comparable 5-year patient-reported outcomes and changes in patient-reported outcomes (eg, knee pain, knee symptoms, activities of daily living, sport and recreational levels, knee-related quality of life, general physical health, and general mental health). Patients in the optional-delayed ACL-reconstruction group had greater mechanical knee instability than patients who received early ACL reconstruction; however, this was primarily among the patients opting for conservative management alone. In the overall sample, 61 knees (51%) required meniscal surgery over 5 years, regardless of treatment group. At 5 years, radiographs were available for 113 patients (93%). Overall, 29 patients (26%) had knee osteoarthritis at 5 years. Specifically, 13 patients (12%) developed tibiofemoral radiographic osteoarthritis (9 patients [16%] in the early ACL-reconstruction group, 4 [7%] in the optional-delayed ACL-reconstruction group) and 22 (19%) developed patellofemoral osteoarthritis (14 patients [24%] in the early ACL-reconstruction group, 8 [15%] in the optional-delayed ACL-reconstruction group). Patients with patellar tendon grafts (n = 40) had a greater incidence of ipsilateral patellofemoral osteoarthritis than patients with hamstrings tendon grafts (n = 51), but the 2 groups had similar incidences of ipsilateral tibiofemoral osteoarthritis. Six knees (5%) had both tibiofemoral and patellofemoral osteoarthritis.

The authors studied a total of 121 moderately active adults (age = 18–35 years) with an acute ACL rupture in a knee with no other history of trauma. Excluded were patients with a collateral ligament rupture, full-thickness cartilage defect, or extensive meniscal fixation. One patient assigned to the early ACL-reconstruction group did not attend the 5-year follow-up visit. Patients were randomly assigned to (1) an early ACL reconstruction plus structured rehabilitation group (n = 62, surgery within 10 weeks of injury) or (2) optional-delayed ACL reconstruction plus structured rehabilitation group (n = 59). The primary outcome measure was change in the average of 4 out of 5 subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS). The authors also assessed crude KOOS (combined 4 subscales), KOOS subscale scores, general physical and mental health (Short-Form 36), activity level (Tegner Activity Scale), mechanical knee stability (Lachman and pivot shift tests), meniscal surgery status, and presence of knee osteoarthritis on radiographs.

Reconstruction is often recommended after anterior cruciate ligament (ACL) rupture. However, some clinicians advocate nonsurgical treatment or at least attempting nonsurgical treatment with an optional-delayed ACL reconstruction. Unfortunately, the literature comparing the long-term efficacy of these treatment strategies is scarce, of low methodologic quality, marred by inconsistent surgical methods (eg, different ACL grafts, various levels of meniscal resection), and lagging behind rapidly changing surgical standards. Based on the available literature, 32% to 51% of patients who underwent ACL reconstruction had tibiofemoral knee osteoarthritis at 10- to 14-year follow-up compared with 24% to 42% of patients who received nonsurgical care.1 Patients undergoing ACL reconstruction may have a higher prevalence of knee osteoarthritis later in life, but until this recent high-quality randomized clinical trial by Frobell et al,2,3 no definitive data were available to compare treatment strategies. This clinical trial is the only study to directly compare early ACL reconstruction with an optional-delayed ACL-reconstruction treatment strategy.

The current results by Frobell et al2 are an extended follow-up of the randomized clinical trial.3 In the initial article,3 the authors described no differences among treatment strategies in patient-reported outcomes over the first 2 years of follow-up.3 Based on the results of this clinical trial,2,3 participants with early ACL reconstruction did not experience better outcomes at 2 or 5 years than participants who received optional-delayed ACL reconstruction. Furthermore, the authors found no differences at either time point among participants with early ACL reconstruction, delayed ACL reconstruction, or no ACL reconstruction (rehabilitation alone). Therefore, contrary to current practice, Frobell et al2 concluded that “these results should encourage clinicians and young active adult patients to consider rehabilitation as a primary treatment option for an acute ACL tear.”2

Among participants randomized to the optional-delayed ACL-reconstruction group, 30 participants (51%) opted for a delayed ACL reconstruction.2 Twenty-three of these participants decided to undergo the delayed surgery within 2 years of ACL injury. Accordingly, patients need to be informed that both treatment strategies may have similar outcomes and that if conservative treatment fails, it will likely be within the first 2 years postinjury. Although they were not the focus of the current study, patient demographics and activity levels may be important for determining why 49% of participants responded favorably to nonsurgical treatment.1,4 Some of these participants may be copers: ACL-deficient individuals who sufficiently stabilize the knee to allow them to return to physical activity without episodes of instability. Another group of these participants may be adapters, who change their level of activity to function without an ACL. Unfortunately, adapters may be the predominant group of patients after an ACL injury, which is concerning because 1 goal of an ACL reconstruction is to promote a safe and effective return to physical activities. At 2 years postinjury, Frobell et al3 found that only 44% and 36% of participants with early or optional-delayed ACL reconstruction, respectively, had returned to their preinjury level of activity. At 5 years, 20% to 22% of participants undergoing early ACL reconstruction, delayed ACL reconstruction, or rehabilitation alone were competing at their preinjury level of activity.2 However, in the original study, the authors did not define participants as copers or adapters, which makes it difficult to determine why some participants returned to competition and others did not. Within the sports medicine community, we must recognize this as a sign that our current strategies may be failing to achieve the goal of a safe return to preinjury competition for most ACL-injured patients.

This study also provides some of the best estimates for the incidence of knee osteoarthritis after different ACL treatment strategies. Frobell et al2 reported that 26% of patients (n = 29) had radiographic knee osteoarthritis within 5 years of injury, regardless of the treatment strategy. Furthermore, 61 patients from the clinical trial had magnetic resonance imaging at baseline (<5 weeks), 3 months, 6 months, 1 year, and 2 years postinjury. These patients had cartilage thinning in the trochlea and cartilage thickening in the central medial femur (possibly from cartilage swelling), regardless of treatment.5 These cartilage changes may indicate that the path to joint failure begins within the first 2 years after an ACL injury. Ostensibly, within 5 years after injury, the risk of developing knee osteoarthritis is elevated. This risk may be attributed to the injury and not be ameliorable by current treatment strategies, such as those assessed by Frobell et al.2 Some ACL-injured patients, regardless of treatment strategy, may be burdened by knee osteoarthritis for more than half their lives, which may lead to considerable psychosocial and economic costs (eg, health care expenses, work loss). Such an outcome is not acceptable for this patient population, and as a health care community, we must strive to find strategies to reduce the risk of knee osteoarthritis and its long-term consequences (eg, pain, disability).

Limiting factors for this study are a relatively short postsurgical follow-up (5 years) and the confounding effect of meniscal surgery (51% of knees), particularly within the first year after the injury and regardless of treatment strategy. Because so many knees had meniscal damage, it is difficult to determine if the osteoarthritis was attributable to the ACL injury, the meniscal injury, or both. Accordingly, the long-term implications of these ACL treatment strategies on radiographic and symptomatic knee osteoarthritis are yet to be determined.