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  • Study: A Few Tests (And Demographic Variables) Can Help Predict Success of Nonsurgical Treatment of ACL Injury in Athletes

    In brief:

    • Researchers in Norway and the US looked at tests and measures of 118 athletes who experienced an anterior cruciate ligament (ACL) rupture and did not have surgery within the first 6 months of the incident.
    • The same tests were administered both at baseline (as soon as possible after the injury) and then after 5 weeks of rehabilitation. Researchers then tracked the patients and administered the International Knee Documentation Committee subjective knee form (IKDC) after 2 years for all participants who did not eventually have surgery.
    • Of 97 patients reporting IKDC scores, 53% reported successful outcomes (at or above 15th percentile).
    • At both baseline and 5 weeks, the strongest indicators of later success of nonsurgical approaches were older age and being female. Higher quadriceps symmetry scores and Knee Outcome Survey – Activities of Daily Living Scale (KOS-ADLS) scores were predictive at baseline; higher IKDC scores were predictive of success after 5 weeks of rehabilitation.
    • Researchers believe their findings are an easy way to help patients and clinicians make decisions about whether to pursue surgical versus nonsurgical treatment for ACL injury.

    For athletes with ACL injuries, deciding whether to pursue surgical versus nonsurgical treatment can be a tough call. Now authors of a new study say that a few tests and outcome measures—and a few demographic factors—can help to shed light on the chances of a nonsurgical approach leading to success.

    The study, conducted in Delaware and Oslo, Norway, included 118 patients who experienced a unilateral ACL rupture and did not elect to have ACL reconstruction surgery (ACLR) by 6 months after the injury (although some did wind up undergoing surgery later on). All of the patients reported participation in a "pivoting sport"—for example, soccer, football, handball, basketball, tennis, skiing, snowboarding, baseball, or softball—for at least 50 hours a year. Researchers focused on 2-year outcomes for these patients in an effort to find out possible predictors for success in nonsurgical treatment, both at baseline and after a 5-week rehabilitation program.

    All participants first underwent rehabilitation to address effusion and range-of-motion deficits, and then were administered a battery of tests as well as the KOS-ADLS and the IKDC. Next, patients participated in a 5-week neuromuscular and strength training program that included 10 sessions of perturbation training, and were administered the same tests and measures. Researchers then tracked the patients for 2 years after baseline and readministered the IKDC. Researchers labeled a nonsurgical approach a success if, after 2 years, nonsurgical participants recorded IKDC scores at or above the 15th normative percentile.

    As for the participants, age at baseline ranged from 18 to 39, with a mean age of 28.6, and a fairly even split between males and females (49.2% and 50.8%, respectively). Demographics at the Oslo and Delaware sites didn't vary much in terms of age, sex, or preinjury activity, but patients in Delaware did report a higher average body mass than the cohort in Oslo. The study was published in the Orthopaedic Journal of Sports Medicine.

    Among the findings:

    • Of the 97 patients for whom 2-year IKDC scores were available, 52 (53%) were found to have a successful outcome; of the 45 patients classified as having an unsuccessful outcome, 33 underwent late ACLR, with 12 remaining nonsurgically treated but scoring below the target IKDC percentile.
    • Patients who scored above the target percentile at the 2-year followup averaged a 94.2 on the 100-point IKDC scale; those who scored below the target averaged a score of 73.2.
    • When comparing the results with tests and measures conducted at baseline, higher KOS-ADLS scores and quadriceps symmetry index scores (LSI) above 89% as assessed through the single-leg hop test were predictive of success after 2 years. Older age and being female also increased the chance of a successful outcome.
    • The 5-week assessments yielded somewhat different predictors of success from the baseline tests, with a higher IKDC score being a stronger indicator of future success. As with baseline assessments, older age and being female increased the odds of success at the 2-year mark, but the LSI score didn't generate any predictive power. "It is possible that when knee function improves with rehabilitation, the measures of knee function lose the variance that is required for predictive ability," authors write.

    Authors see several compelling reasons for using these tests to help make a patient arrive at a decision about whether to continue nonsurgical treatment—primary among them the fact that the models can be easily applied and yield reliable results. As an example, they calculate that a 30-year-old women who scores 90 on the KOS-ADLS and has an LSI of 90% or above early after injury has an 85% probability of a successful nonsurgical outcome 2 years after injury. By contrast the same woman scoring a 65 on the KOS-ADLS and an LSI below 90% would have only a 29% probability of success after 2 years.

    "These differences in prognoses provide a powerful argument for why clinicians should routinely assess the patient's knee function after injury," authors write.

    As for the better probabilities of success with age, authors point to a problem in ACL treatment overall—namely, that younger athletes also tend to have lower success rates for surgical treatment compared with older athletes.

    "Our results in nonsurgically treated patients, as well as previous studies on surgically treated patients, support the growing concern that our current treatment methods are not successful enough for the youngest and most active patient group," authors write. "For those who have good prognoses with nonsurgical treatment, however, our results can help clinicians and patients to have more confidence in a nonsurgical treatment choice (active rehabilitation)."

    The researchers believe their study is a solid investigation into predictive factors around ACL treatment, but they see possibility for the inclusion of more variables as predictors of success, including anatomic factors, associated injuries, laxity, and psychological components. Still, they see the current results as helpful.

    "Clinicians and patients can have more confidence in a nonsurgical treatment choice in athletes who are female, are older, and have good knee function early after ACL injury," authors write. "A simple set of measures, assessed either before or after a short period of rehabilitation, can provide 2-year prognoses and thereby aid shared treatment decision making."

    APTA members Elizabeth Wellsandt, PT, DPT, PhD; and Lynn Snyder-Mackler, PT, ScD, FAPTA, are among the coauthors of the article.

    Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association's PTNow website.