2025 ISAKOS Biennial Congress ePoster
Changes In Foot Pressure Among Patients With Varus Knee Osteoarthritis Undergoing Bilateral Simultaneous Total Knee Arthroplasty – A Prospective Observational Pedobarographic Assessment
Roop Bhushan Kalia, M.S (Orthopaedics), Dehradun, Uttarakhand INDIA
Divyansh Sharma, MBBS,M.S (Orthopaedics), Dehradun, Uttarakhand INDIA
Pradeep Kumar Meena, MBBS,M.S(Orthopaedics), Dehradun, Uttarakhand INDIA
Raj Kumar Yadav, MBBS,M.D, Dehradun, Uttarakhand INDIA
Ankit Gaurav, MS ORTHOPAEDICS, Chandigarh, Chandigarh INDIA
All India Institute of Medical Sciences, Rishikesh,Dehradun, Uttarakhand, INDIA
FDA Status Not Applicable
Summary
A marked redistribution of pressure from lateral to medial side of foot occurs after TKA and was more pronounced in greater degrees of varus deformity. Correcting the knee varus deformity following TKA also normalises the hindfoot alignment and restores the foot loading pattern.
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Abstract
Introduction
Severe knee osteoarthritis with significant disability requires surgical management by Total knee arthroplasty (TKA). Many severe osteoarthritic varus knees have compensatory foot and ankle malalignment which keeps progressing with time. With hindfoot valgus there are significant changes in the weight transmission in the foot during standing and ambulation. After TKA there is change in the hindfoot bio-mechanics and weight transmission in the foot.
Aims and objectives
To determine the pedobarographic patterns in patients with primary varus osteoarthritis knee undergoing bilateral total knee arthroplasty by assessing the changes in pedobarographic parameters pre-operative and post-operatively. Pre-operative and post-operative AOFAS ankle hindfoot score and FAAM (foot and ankle ability measure) were assessed to determine the effect of TKA on ankle function.
Materials And Methods
A total of 31 patients (62 knees) were included in the final results and underwent simultaneous bilateral total knee arthroplasty. Data on the patient’s age, sex, height and body mass index (BMI) was recorded. HKA angles were recorded for both knees using Medicad software. Based on the deformity patients were divided into group 1 with HKA angles between 170-180 and group 2 with HKA angles less than 170 degrees. Foot pressure measurements were done using BTS P-walk system in static and walking mode and recorded preoperatively and at 6 months postoperatively. Similarly, PROM’s were also recorded preoperatively and at 6 months follow-up. Statistical significance was set at a P-value <0.05.
Results
The mean age and BMI of patients was 61.42 with 95% C.I (58.93-63.90) and 28.68 with 95% C.I(27.35 – 30.01). 23(37.1%) knees fell in group 1 (HKA 170-180) and 39(62.9%) knees were in group 2 (HKA<170). In comparison of foot pressure according to severity of knee deformity, there was a statistically significant difference (p=0.029) between group 1 and group 2 in preoperative static pressures in head of 5th metatarsal(M5). The M5 preoperative static pressure was 49(IQR=29-68) and 34(IQR=18-54) in group 1 and 2 respectively. Similarly, there was a statistically significant difference (p=0.028) between group 1 and group 2 in postoperative static pressures of heel. The average heel postoperative static pressure was 159.5(IQR=112.5-192.5) and 224.5(IQR=136-311.5) in group 1 and 2 respectively. Differences were more accurate when standing than in walking. Statistically significant improvement was seen in AOFAS ankle hindfoot and FAAM scores post-operatively with p-value <0.001.
Conclusion
A marked redistribution of pressure from lateral to medial side of foot was more pronounced in greater degrees of varus deformity. Correcting the knee varus deformity following TKA also normalises the hindfoot alignment and restores the foot loading pattern.
Conflict of interest
None.