Foot pressure pattern, hindfoot deformities, and their associations with foot pain in individuals with advanced medial knee osteoarthritis

This survey clarified foot pressure patterns and hindfoot deformities in individuals with advanced knee osteoarthritis (OA) and analyzed their associations with foot pain. Sixty-four individuals with unilateral knee OA who underwent total knee arthroplasty (TKA) were divided into the following groups: no foot pain (n = 26; men:women, 4:22; mean age, 73.7 years), foot pain resolved after TKA (12; 2:10; 75.8), and foot pain remaining after TKA (26; 4:22; 74.7). Elderly individuals without pain or deformity in either knee (54; 10:44; 74.3) were controls. Navicular height ratio of the medial longitudinal arch, leg-heel angle, and partial foot pressure as the percentage of body weight (%PFP) were calculated.%PFPs of the medial and lateral heel regions before TKA were significantly lower for the no foot pain group than for controls. One year after TKA, %PFP improved significantly. In the foot pain resolved group, before TKA, the leg-heel angle was significantly higher, and%PFPs of the medial and lateral heel regions and navicular height ratio before TKA were significantly lower than those of controls. One year after TKA, all parameters improved significantly. In the foot pain remaining group, similar abnormalities were observed before TKA; however, significant improvement was only observed for%PFP of the medial heel region 1 year after TKA. More than half of the patients with advanced knee OA had foot pain. This improved in approximately one-third, 1 year after TKA. Hindfoot deformities are probably associated with foot pain in individuals with advanced knee OA.