Predicting no return to sports after three months in patients with traumatic knee complaints in general practice by combining patient characteristics, trauma characteristics and knee complaints.

It remains unclear to what extent patients with traumatic knee complaints aged 18-45 years seen in general practice experience difficulties with return to sports. This study aims to determine the proportion of patients with a knee trauma that return to sports at six weeks and three months follow-up. Also examined were associations between no return to sports and baseline patient/trauma characteristics, knee complaints and MR (magnetic resonance) findings, as well as the additive value of MR findings. Included were patients with traumatic knee complaints participating in a randomized controlled trial assessing the cost-effectiveness of an MR scan in general practice. Patients were classified as 'no return to sports' or 'return to sports' (sports on pre-injury or adapted level). Potential baseline predictors for no return to sports were assessed using logistic regression analyses. The area under the curves (AUC) was compared. At six weeks and three months follow-up, 147 (59%) and 175 (74%) patients, respectively, reported return to sports. Combining patient characteristics, trauma characteristics and knee complaints predicted no return to sports with an AUC of 0.86 (95%CI: 0.81-0.90) at six weeks and of 0.82 (95%CI: 0.76-0.88) at three months follow-up. After adding MR findings, the AUC was 0.79 (95%CI: 0.71-0.87) at six weeks and 0.79 (95%CI: 0.70-0.88) at three months follow-up. Three out of four patients with a knee trauma in general practice reported return to sports at three months follow-up. A combination of patient/trauma characteristics and knee complaints predicted no return to sports, whereas MR findings had no additive value.  Dutch trial registration: registration number: NTR3689. registration date: 7 November 2012.