Evaluation of distraction apparatus for correcting flexion contractures deformities of the knee joint / 中国矫形外科杂志

ABSTRACT

[Objective]To study the safety,clinical effect and therapeutic characteristics of distraction apparatus for correcting flexion contracture deformities of the knee joint by evaluating the clinical outcomes and investigating the results of biomechanic test.[Method]Forty-nine patients (included 52 knees) were treated by the standardized distraction apparatus and the comprehensive assessment standard was adopted to evaluate the clinical outcomes.Five patients were examined by three-dimensional CT of the knee joints pre-operatively and post-operatively to observe the changes in the knee structure.To observe the effect of distraction on the popliteal artery and the limb nerves,the popliteal artery diameter and blood flow speed were examined in 15 patients and the regio cruris electromyogram and nerve conduction velocity were examined in 6 patients before and after treatment.Three different means of distraction and measurement were underwent in 3 patients so as to observe the changes in the flexion curve and force of posterior soft tissues of the knee.[Result]All patients (52 knees) regained congruous structure and better function,the final excellent and good result rate was 65%.Three-dimensional CT examination of 5 patients showed that the postoperative knee joint structures were superior to the preoperative ones and there weren't damage of articular surface.The statistic results indicated that the popliteal arteries weren't obviously disturbed by distraction,whereas the limb nerves were probably disturbed temporarily.Three methods of distraction and measurement in 3 patients showed different outcomes,indicating that the effect of distraction on soft tissues was influenced by the distraction method,the ages of patients and the extents of deformities of the limb.[Conclusion]The distraction speed of therapeutic method is safe,reasonable and effective in correcting flexion contracture of the knee joint;The distraction force on posterior soft tissues of the knee is influenced by various elements,thus,the distraction speed should be individualized.Low-load and steady stretch are advantageous to soft tissue regeneration and safer.