Question:
In young adults with an acute anterior cruciate ligament (ACL) tear, is a strategy of rehabilitation plus early ACL reconstruction superior to rehabilitation with delayed ACL reconstruction if needed?
Design:
Randomized (allocation concealed), unblinded, controlled trial with a two-year follow-up (Knee Anterior Cruciate Ligament, Nonsurgical versus Surgical Treatment [KANON] Study).
Setting:
Helsingborg and Lund University hospitals in Sweden.
Patients:
141 patients who were eighteen to thirty-five years of age and presented to the emergency department with recent knee trauma. Inclusion criteria were rotational trauma to a previously uninjured knee within the past 4 weeks, ACL insufficiency, and participation in recreational or competitive sports (Tegner Activity Scale [TAS] score of 5 to 9). Exclusion criteria included total collateral ligament rupture and full-thickness cartilage lesion. 121 patients (mean age 26.1 y, 74% men) were included in the analysis.
Intervention:
Patients were allocated to a strategy of structured rehabilitation plus ACL reconstruction within ten weeks (n = 62) or a strategy of structured rehabilitation plus optional delayed ACL reconstruction (n = 59). Rehabilitation was supervised by physiotherapists with goals for range of motion, muscle function, and functional performance at each of four levels. ACL reconstruction was performed by four senior knee surgeons using the patella-tendon procedure or the hamstring-tendon procedure according to surgeon preference. Patients in the optional delayed reconstruction group were referred for reconstruction if they had a self-reported symptomatic instability caused by ACL insufficiency and a positive result on a pivot-shift test.
Main outcome measures:
The primary outcome was change in mean score for 4 of 5 Knee Injury and Osteoarthritis Outcome Score subscales (KOOS4): pain, symptoms, difficulty in sports and recreational activities, and quality of life (score range, 0 [worst] to 100 [best]). Secondary outcomes included results on all five KOOS subscales (the fifth was activities of daily living), scores on the Short-Form 36 (SF-36) physical and mental components (score range, 0 [worst] to 100 [best]), results on the TAS, the proportion of patients who had a return to preinjury activity level or higher, the area under the curve for absolute KOOS4 scores, and the proportion of patients with a KOOS quality-of-life score of <44.
Main results:
The study had 80% power to detect a 10-point difference between groups in change from baseline in the KOOS4 score. The change from baseline in KOOS4 score did not differ between the early reconstruction and delayed reconstruction groups (Table). The groups did not differ for any secondary outcomes.
Conclusion:
In young adults with an acute anterior cruciate ligament tear, a strategy of rehabilitation plus early reconstruction was not superior to rehabilitation with the option of delayed reconstruction.
Frobell and colleagues are to be congratulated for their attempt to determine whether rehabilitation with early ACL reconstruction is better than delayed optional ACL reconstruction if needed. Their results at two years showed no difference for any outcome measures. However, two years is probably insufficient to resolve this controversy. ACL-injured knees acquire varying degrees of arthrosis1 with time, which might be the ultimate outcome.
In the rehabilitation plus early ACL reconstruction group, two of sixty-nine patients were excluded because of "extensive meniscal fixation." In the rehabilitation and optional delayed ACL reconstruction group, five of seventy-two patients were excluded for "extensive meniscal fixation." These patients were excluded because they were prescribed a different rehabilitation program.
In the rehabilitation and early ACL reconstruction group, there was one event of signs and symptoms of a torn meniscus, compared with thirteen in the delayed group. There were two events of instability (either proven or by complaint) in the early reconstruction group and nineteen in the delayed group. While these events did not influence the outcome scores, they might adversely influence the final outcome with longer follow-up.
In summary, only results with longer follow-up will definitively show that a nonsurgical approach is better than or equally beneficial as early ACL reconstruction.
Reference
Lohmander
LS;
Englund
PM;
Dahl
LL;
Roos
EM. The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med.
2007;35:1756-69.[PubMed] [CrossRef]