Case: A 51-year-old patient with medial compartment osteoarthritis of the left knee underwent an osteotomy of the proximal aspect of the fibula. Gait kinematic data were collected before and after the surgery with use of an optical tracking system during level walking. A sharp increase of approximately 5° to 7° in femoral abduction and a 5° to 8° increase in femoral external rotation were exhibited at 3 months postsurgery. At 1 year postsurgery, femoral external rotation had increased by 3° to 5°. There was also an increase of distal femoral translation (approximately 2 to 10 mm).
Conclusion: An osteotomy of the proximal aspect of the fibula altered the kinematics by increasing valgus, femoral external rotation, and distal translation of the knee. These alterations may help reduce knee pain and improve early functional recovery.