How surgeons correct bow-legged (varus) knees during knee replacement
Correcting varus deformity
In simple words
Some people with knee arthritis develop a severely bowed (bow-legged, or 'varus') knee. This paper describes the surgical technique used to straighten such knees during a total knee replacement, and the results.
What the study looked at
173 knee replacements in 117 patients whose knees were bowed by more than 20° (about 23° on average), followed for 2 to 9 years. Tight tissues on the inner side were released step by step, excess bone at the inner edge of the shin bone was trimmed, and a bone cut below the knee was added when the deformity lay outside the joint.
What it found
The average bow of about 23° was corrected to about 5° of normal (valgus) alignment, with 86% of knees in the target range. Knee Society scores rose from about 23 to 91, and function scores from about 23 to 72. 28 of 30 bone grafts healed, no patient reported significant instability, and 3 knees showed loosening of the shin-bone component.
Why it matters for patients
Even badly bowed knees can be straightened and kept stable with standard implants, without needing more constrained, bulkier designs.
Authors: Mullaji A, Marawar S, Sharma A · J Arthroplasty 2007;22(4 Suppl 1):15–19