Gradual distraction for treatment of severe knee flexion contractures using the Ilizarov’s apparatus

Background: Knee flexion contractures result in a significant amount of functional disability due to reduced mobility and limb length discrepancy. Treatment options include non-surgical methods like serial casting, dynamic splinting and traction or surgical methods like osteotomies and soft tissue procedures. External fixation has emerged as a highly successful means of achieving controlled gradual correction of joint contractures with low rates of complications including recurrence. The aim of this study is to evaluate the functional outcome in terms of residual deformity and change in ambulatory status following correction using the Ilizarov’s apparatus.Methods: 12 patients with knee flexion contractures ranging from 20°-70° underwent correction using the Ilizarov’s external fixator (IEF). The use of simple mathematic formulae enabled us to calculate and estimate the rate and duration of distraction. End results were assessed at one year by the residual contracture as: Excellent: 0-5°, Good: 6-15°, Fair: 16-30° and Poor: >30°.Results: The functional assessment was graded as excellent in 7, good in 4 and fair in 1 out of 12 patients. All patients were independent ambulators and only 1 out of 12 patients required an additional orthosis for maintenance of the correction.Conclusions: The IEF is a safe and precise modality even for the most complex contractures of the knee. Accurate placement of the hinges along the center of rotation of the knee avoids undue subluxation of the tibia during correction. In order to ensure a low rate of complications, it is imperative to have a detailed pre-operative plan and all principles of fixation should be meticulously adhered to.