Last reviewed: September 29, 2026

It is fairly common. Often it is because straightening the leg changes how the ankle carries weight, and it often eases, though not always.

A knee that has slowly become bowed or knock-kneed changes how the ankle and heel sit under it. Over years, the heel and ankle tilt to keep the foot flat on the ground. A knee replacement straightens the leg in one operation, and the ankle and heel then have to adjust again.

In one study, about 1 in 4 people reported new or worse ankle symptoms three months after surgery. In other studies, ankle pain became less common after surgery on average, especially when the heel had been turned outward beforehand. These studies are small, and the overall evidence is low quality.

Ankle pain afterward is more likely in people who already had ankle arthritis, a heel turned inward, or an ankle tilted before surgery, and after very large corrections of a bowed or knock-kneed leg. Studies disagree on whether a stiff heel matters. Higher body weight was linked in one study. In people over 65, the heel adjusted less to the new alignment.

How long it lasts is not well studied. In one study, ankle pain became less common over the first year, and an ankle tilted before surgery predicted pain still present at a year. After very large corrections, symptoms were still present about five years later.

Straightening the leg usually also makes it a little longer. No study has linked that to ankle pain. Whether a high-arched or flat foot before surgery makes ankle pain more likely has not been studied.

In general:

  • Tell your surgeon before surgery about any ankle pain, ankle arthritis or foot problem.
  • New ankle pain after a knee replacement is worth mentioning at follow-up, even when the knee is doing well.
  • Pain, swelling or tenderness in the calf needs to be seen promptly.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

  • Rühling M, et al. Increased Ankle Pain After Total Knee Arthroplasty Is Associated With a Preoperative Lateralized Gait and Talar Tilt, but Not With Ankle Laxity or the Range of Motion of the Subtalar Joint. Bone Joint J. 2023. https://doi.org/10.1302/0301-620X.105B11.BJJ-2023-0419.R1
  • Sakai T, et al. Abnormal Preoperative Tibiotalar Tilt Predicts Residual Ankle Pain After Mechanical-Alignment Total Knee Arthroplasty: A Retrospective Cohort Study. The Knee. 2026. https://doi.org/10.1016/j.knee.2026.104496
  • Chang CB, et al. Concomitant Ankle Osteoarthritis Is Related to Increased Ankle Pain and a Worse Clinical Outcome Following Total Knee Arthroplasty. J Bone Joint Surg Am. 2018. https://doi.org/10.2106/JBJS.17.00883
  • Turhan MK, et al. Risk Factors for Foot and Ankle Pain After Total Knee Arthroplasty and the Role of Subtalar Joint Motion Capacity. J Am Acad Orthop Surg. 2025. https://doi.org/10.5435/JAAOS-D-25-00479
  • Graef F, et al. Correction of Excessive Intraarticular Varus Deformities in Total Knee Arthroplasty Is Associated With Deteriorated Postoperative Ankle Function. Knee Surg Sports Traumatol Arthrosc. 2020. https://doi.org/10.1007/s00167-019-05812-9
  • Graef F, et al. Correction of Severe Valgus Osteoarthritis by Total Knee Arthroplasty Is Associated With Increased Postoperative Ankle Symptoms. Knee Surg Sports Traumatol Arthrosc. 2022. https://doi.org/10.1007/s00167-020-06246-4
  • Kikuchi N, et al. Varus Knee Osteoarthritis With Ankle Osteoarthritis Demonstrates Greater Hindfoot Inversion and Larger Ankle Inversion Loading During Gait Following Total Knee Arthroplasty Compared to Varus Knee Osteoarthritis Alone. Knee Surg Sports Traumatol Arthrosc. 2024. https://doi.org/10.1002/ksa.12249
  • Takenaka T, et al. Hindfoot Alignment at One Year After Total Knee Arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2016. https://doi.org/10.1007/s00167-015-3916-x
  • Diao N, et al. Association Between Changes in Hip-Knee-Ankle Angle and Hindfoot Alignment After Total Knee Arthroplasty for Varus Knee Osteoarthritis. BMC Musculoskelet Disord. 2021. https://doi.org/10.1186/s12891-021-04488-y
  • Kapoor V, et al. Ankle and Hindfoot Alignment Changes in Advanced OA Varus Knees After Cruciate Retaining Total Knee Arthroplasty: A Prospective Cohort Study. Indian J Orthop. 2022. https://doi.org/10.1007/s43465-022-00754-w
  • Prasad AR, et al. Does Total Knee Arthroplasty Affect Ankle and Hindfoot Alignment? A Prospective Study on Functional and Radiological Outcome. Indian J Orthop. 2025. https://doi.org/10.1007/s43465-025-01539-7
  • Butler JJ, et al. Alignment of the Hindfoot Following Total Knee Arthroplasty: A Systematic Review. World J Orthop. 2021. https://doi.org/10.5312/wjo.v12.i10.791
  • Chalmers BP, et al. Characterizing the Magnitude of and Risk Factors for Functional Limb Lengthening in Patients Undergoing Primary Total Knee Arthroplasty. HSS J. 2022. https://doi.org/10.1177/15563316211009140

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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