Prognostic factors and the value of radiographic osteoarthritis for persistent complaints after referral for ankle radiography

Background: Ankle symptoms are a common reason to consult the general practitioner and often persist for years. In a population referred for ankle radiography, the prevalence of radiographic osteoarthritis (OA) is substantial, but its additional predictive value for persistent symptoms is unknown. Therefore, we examined the prognosis of symptoms 2–3 years after referral for ankle radiography, assessed clinical prognostic factors, and the additional predictive value of radiographic OA for persistent ankle complaints. Methods: We included 893 adults referred for ankle radiography and studied the following candidate prognostic factors at baseline: age, sex, body mass index (BMI), referral for chronic complaints (>3 months), pain during activity (NRS-11) and presence of stiffness and functional loss as predominant symptom. X-rays were scored for radiographic OA. After 2–3 years participants were invited for a follow-up questionnaire including persistence of ankle complaints. To assess prognostic factors for persistent complaints, uni- and multivariable logistic regression were used. Results: Of the 194 responders at follow-up, ankle complaints persisted in 71(36.6 %). BMI (OR 1.08; 95 % CI 1.01–1.15), stiffness as predominant symptom (OR 1.69; 95 % CI 0.89–3.21), and chronic complaints (OR 2.84; 95 % CI 1.45–5.57) were in the initial model for persistent complaints (AUC=0.69). After adding radiographic OA (OR 2.36; 95 % CI 1.01–5.50), the AUC of the final model became 0.70. Conclusion: Ankle complaints persist in a considerable proportion of patients 2–3 years after referral for ankle radiography. BMI, chronic complaints and radiographic OA are prognostic factors for persistent complaints, but the additional predictive value of radiographic OA on top of clinical factors is negligible.