COMPUTER-ASSISTED DISTRACTION OSTEOGENESIS USING THE TAYLOR FRAME: INITIAL CLINICAL EXPERIENCES

Abstract

Our research group has recent clinical experience with our novel computer-assisted method of bone deformity correction using the Taylor spatial frame (Smith & Nephew, Memphis, TN). Practitioners of the Taylor spatial frame admit that there is a steep learning curve in using the frame. This is in large part due to the difficulty in accurately measuring 13 frame parameters and mounting the frame to the patient without inducing residual rotational and translational errors. Our technique aims to reduce complications due to these factors by preoperatively planning the desired correction and calculating the correction based on the actual three-dimensional location of the frame with respect to the anatomy, rather than from traditional radiographs. The surgeon has greater flexibility in choosing the position of the rings since this technique does not depend on placing the rings in a particular configuration.

Four clinical procedures have been performed at Kingston General Hospital (Kingston, ON, Canada) to date. The first patient presented with a proximal tibial growth-plate arrest that was secondary to a fracture. The result was a recurvatum deformity secondary to an eccentric growth arrest anteriorly. This deformity caused a stretch of the posterior capsule and posterior cruciate ligament that produced an unstable knee. The achieved correction, measured radiographically, was from an initial; − 14 degrees to a final +7 degrees of posterior slope.

The second patient presented with a proximal tibial soft tissue imbalance that was thought would eventually lead to a recurvatum deformity. An increase in the posterior slope of the tibia was induced to compensate for the soft tissue deformity. The radiographic correction was an increase in posterior slope from +7 degrees to +14 degrees and from 5 degrees varus to 8 degrees varus.

The third patient patient presented with a partially-healed malunited tibial fracture with 14 degrees of proximal tibial varus and 16 degrees of posterior slope. In spite of an uncomplicated frame application, the patient was not compliant with post-operative care and the frame was removed before correction could be achieved.

The fourth patient underwent a limb lengthening. At the time of writing, the adjustment schedule had not been completed.

Our computer-assisted procedure appears to be an effective method of improving Taylor spatial frame use. The senior surgeon (DPB) noted that the procedure is easy to perform, he no longer needs to measure the 13 frame parameters, and he can plan the correction in three dimensions. We also have the ability to modify the pace of the correction schedule to accommodate the rate of bone growth for each individual patient. Drawbacks of the technique include the requirements for a preoperative CT scan and a segmentation of the scan to produce the three-dimensional computer models.