Valuation of the effect of primary total knee arthroplasty performed for advanced-stage osteoarthritis on plantar pressure using plantar pressure analysis

Object: This prospective study aimed to evaluate the relationship between knee mechanical alignment and static plantar pressure distribution in patients undergoing total knee arthroplasty (TKA). Methods: A total of 60 patients who underwent TKA at the Department of Orthopedics and Traumatology, Afyonkarahisar Health Sciences University, were included. Preoperative and postoperative demographic data, body mass index (BMI), Q angle, mechanical axis (MA), and static plantar pressure parameters were analyzed separately for the operated and non-operated feet. Results: The mean preoperative BMI was 33.01±5,71 kg/m² in males and 33.22±5,32 kg/m² in females, with no significant postoperative change (p>0.05). Q angle increased significantly after surgery, from 4,44±1,92° to 6,99±2,10° in males (p=0.006) and from 1,93±3,91° to 6,40±2,14° in females (p<0.001). Mechanical axis values improved significantly in both sexes (female p<0.001; male p=0.001). While no significant change was observed in plantar pressure parameters of the operated foot, a borderline decrease in total pressure was noted among males. No significant change was detected on the non-operative side. Conclusion: Despite the significant improvement in knee alignment following TKA, complete symmetry in plantar pressure distribution could not be achieved. The increased load observed on the non-operative foot, particularly in women, indicates that the dynamic adaptation process of lower limb load distribution continues after surgery. These findings highlight the necessity of incorporating plantar pressure analyses and balance exercises into post-TKA rehabilitation programs. Keywords: Knee osteoarthritis, Mechanical axis, Plantar pressure analysis, Static plantar pressure, Total knee arthroplasty