At least 200,000 ACL reconstructions are carried out annually in the U.S., according to the researchers, with an estimated cost of $3 billion. Yet high-quality evidence for this intervention is lacking, they write in the July 22 issue of the New England Journal of Medicine.
ìIt seems like starting out with rehabilitation is a good idea instead of starting out with surgery,î lead author Dr. Richard Frobell of Lund University told Reuters Health.
ìWe already knew that people with low activity levels could manage well with only rehabilitation,î he said. ìBut these were athletes, so that was surprising.î
At two years, less than half of the patients randomly assigned to rehabilitation without early reconstruction had opted for surgery. Although knee stability, a secondary outcome, was greater in the early reconstruction in group, improvements on the Knee Injury and Osteoarthritis Outcome Score (KOOS) were similar in the two groups.
In an editorial, Dr. Bruce Levy of the Mayo Clinic in Rochester, Minnesota, noted that two-year outcomes do not reflect long-term knee function.
ìUltimately, the most important predictor of long-term outcome may not be instability due to ACL deficiency but rather the presence of articular-cartilage or meniscal lesions, which may lead to premature arthritis,î he writes.
Dr. Frobell and colleagues included competitive and recreational athletes aged 18 to 35, who had ACL insufficiency following recent rotational trauma. Those with total collateral ligament rupture or full-thickness cartilage lesions were excluded.
At baseline, there were no differences between the 62 patients in the early reconstruction group and the 59 in the optional reconstruction group. Surgeons performed the patella-tendon or the hamstring-tendon procedure at their discretion.
The primary outcome was the average score on four of the KOOS subscales, that is, pain, symptoms, difficulty in sports and recreational activities, and quality of life (0: worst, 100: best).
At two years, there was no difference in KOOS score improvements between patients who had early reconstruction and those who didnít (mean change, 39.9 vs. 39.4; p=0.96). Patients in the latter group had fewer rehabilitation visits (mean, 53 vs. 63; p=0.05), and 23 (39%) underwent surgery in the two-year period.
The frequency of serious adverse events did not differ significantly between the two groups (p=0.06). Three patients with early reconstruction had ACL graft ruptures and one had arthrofibrosis; there was one rupture in the delayed optional-reconstruction group.
Patient-reported secondary outcomes, including health status and return to preinjury activity levels, were similar. Early-reconstruction patients had better results in knee-stability tests and less anteroposterior laxity on average (6.6 mm vs. 8.3 mm, p=0.001).
ìI guess that mechanical stability at rest is not that important,î Dr. Frobell said. ìIt is more important that you train muscles and nerves to make your knee stable.î
He added that the results might not apply to professional athletes. ìItís very difficult to give scientific advice to professional athletes,î he told Reuters Health. ìThey need to get back on track as soon as possible, and theyíre not very prone to wait and see.î
Dr. Levy noted that different people may have different needs, such as ìan 18-year-old college soccer player who performs repetitive planting, pivoting, and cutting maneuversî and a ì35-year-old who participates in recreational sports such as cycling or jogging.î
ìGiven that no two patients and no two ACL injuries are identical,î he concluded, ìit is extremely difficult to recommend a single treatment strategy for all patients with ACL injuries.î
N Engl J Med 2010; 363:331-342, 386-388.