Medical Officer III Philippine Orthopedic Center PARANAQUE, National Capital Region, Philippines
Objectives: The primary objective of this study was to determine the association of Pes Planus and Hallux Valgus with functional status of patients with knee osteoarthritis.
Design: This was a prospective analytical, cross sectional study examining patients 60 years old and above diagnosed with knee Osteoarthritis. Functional assessment was assessed using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. Anterior-posterior and lateral foot standard radiographs were obtained. A lateral talometatarsal angle greater than 4° was defined as pes planus. A hallux valgus angle greater than 21° was defined as hallux valgus.
Results: Eighty-nine patients were included in the study. Pes planus was seen in 26 patients (38.20%); and hallux valgus was seen in 11 patients (21.35%). Patients without pes planus and hallux valgus had significantly lower scores on WOMAC overall, and across pain, stiffness, and physical function. Pes planus is associated with higher WOMAC scores, after adjusting for age, sex, and BMI of patients (p < 0.001). Patients with hallux valgus are likely to have worse WOMAC scores than those without (p = 0.009), but association was not sustained after adjusting for age, sex, and BMI. There is a moderate and direct correlation between WOMAC scores with lateral talometatarsal angle and hallux valgus angle (p < 0.001). There is a weak and direct correlation between pain domain and hallux valgus angle, as well as stiffness and physical function subscales with both lateral talometatarsal angle and hallux valgus angle.
Conclusions: The study demonstrated the correlation of Pes Planus and Hallux Valgus deformity with moderate and direct correlation with WOMAC disability scores (p < 0.001). The early identification of these foot deformities with simple conventional radiographs, especially in those patients at risk, would allow the clinician to provide an individualized and targeted treatment approach in order to improve the quality of life of our patients.