Lower limb pain in a preadolescent population: Prognosis and risk factors for chronicity - A prospective 1-and 4-year follow-up study

Objective. To determine the short- term and long- term prognosis of preadolescent lower limb pain and to assess factors that contribute to pain persistence at 1-year follow-up and pain recurrence at 4-year follow-up. Methods. A 1- and 4- year follow-up was conducted of a population-based 10- and 12-year old cohort of schoolchildren with lower limb pain at baseline Results. Of the baseline students with lower limb pain, 32% reported pain persistence at 1-year follow-up and 31% reported pain recurrence at 4-year follow- up. Vigorous exercise was the only statistically significant predictor of lower limb pain persistence at 1-year follow-up (odds ratio [OR]: 2.43; 95% confidence interval [CI]: 1.16 - 5.05), whereas at 4- year follow- up (at adolescence), hypermobility was predictive of pain recurrence (OR: 2.93; 95% CI: 1.13 - 7.70). Traumatic lower extremity pain had a 50% lower risk for pain recurrence compared with nontraumatic pain (OR: 0.48; 95% CI: 0.19 - 0.92). Conclusion. Trauma- induced lower extremity pain in preadolescents has a favorable long- term natural course. Children's involvement in vigorous exercise predicts short- term outcome of lower limb pain, whereas hypermobile children have a worse long- term prognosis.