Objective To examine the 6-year course of nontraumatic knee symptoms in adults in general practice, to identify prognostic factors for unfavorable outcome, and to develop a clinical prediction rule. Methods Adults (ages >35 years) with incident nontraumatic knee symptoms (n = 549) were followed for 6 years. Multivariable logistic regression analysis was used to identify prognostic factors associated with an unfavorable outcome, the area under the receiver operating curve (AUC) was calculated to determine discriminative ability, and a clinical prediction rule was developed. Unfavorable outcome is defined as persistent knee symptoms at 6-year followup or having undergone knee replacement surgery during followup. Results At 6-year followup, 42.1% of patients had an unfavorable outcome. Having persistent knee symptoms (odds ratio [OR] 5.31, 95% confidence interval [95% CI] 3.27-8.61) and fulfilling the clinical American College of Rheumatology (ACR) criteria for osteoarthritis (OA; OR 2.65, 95% CI 1.48-4.73) at 1-year followup were significantly associated with unfavorable outcome, while fulfilling the clinical ACR criteria for OA at baseline was not. Baseline factors independently associated with an unfavorable outcome were low/middle education level, comorbidity of the skeletal system, duration of knee symptoms of >3 months, bilateral knee symptoms, self-reported warm knee, history of nontraumatic knee symptoms, valgus alignment, pain at passive knee flexion/extension, and bony enlargement of the knee joint (AUC 0.80). Conclusion Nontraumatic knee symptoms in adults in general practice appear to become a chronic disorder in nearly half of the patients. The developed clinical prediction rule with 10 baseline prognostic factors can be used to select high-risk patients for an unfavorable outcome at long-term followup. Copyright

dx.doi.org/10.1002/acr.20522, hdl.handle.net/1765/31052
Arthritis Care & Research
Erasmus MC: University Medical Center Rotterdam

Kastelein, M, Luijsterburg, P.A.J, Belo, J.N, Verhaar, J.A.N, Koes, B.W, & Bierma-Zeinstra, S.M. (2011). Six-year course and prognosis of nontraumatic knee symptoms in adults in general practice: A prospective cohort study. Arthritis Care & Research, 63(9), 1287–1294. doi:10.1002/acr.20522