Introduction

Osteoarthritis frequently affects multiple joints through the lower limbs. This study sought to examine the incidence of knee pain in subjects undergoing foot or ankle surgery and determine if knee symptoms improved following foot or ankle surgery

Methods

93 subjects undergoing foot or ankle surgery completed patient reported outcomes measures (PROMs) preoperatively and 12 months after surgery including the Foot and Ankle Outcome Score (FAOS) and the Knee Osteoarthritis Outcome JR Scores (KOOS), EQ5D, and satisfaction.

Results

The mean age of the cohort was 63 years (range 24-85), and 60% were female. The proportion reporting knee pain significantly reduced after surgery for the activities of stairs (p=0.031), and standing (p=0.031). A small magnitude but statistically significant increase in the median KOOS Knee Score from 92 before surgery to 100 after surgery (p=0.041) was observed. Any knee pain was reported in 40% before, and 31% at 12 months after foot surgery. Of those reporting preoperative standing knee pain, 61% reported no standing knee pain with 12 months after foot surgery. Of those reporting preoperative knee pain with stairs, 40% reported no standing knee pain with 12 months after foot surgery. The presence of preoperative knee pain did not affect post operative satisfaction (p=0.99), or the proportion who would undergo the same surgery again (p=0.922). Those with preoperative knee pain had an equivalent distribution of change in FAOS at 12 months for pain (p=0.744), symptoms (p=0.301), ADL (p=0.997) and quality of life (p=0.857) compared to those without preoperative knee pain.

Conclusion

Knee pain was reported by 40% of those undergoing foot surgery, and significantly improved after foot surgery in up to 65%. Those with preoperative knee pain experienced at least equivalent improvement in foot related symptoms and mobility compared to those without knee pain.