Abstract
Introduction
A clinical case of catastrophic ring failure in a 13 year old autistic overweight patient during treatment for tibial lengthening and deformity using a Taylor Spatial Frame is reported. Ring failure was noted during the later stages of bone healing and the frame was removed. The clinical outcome was not affected by the catastrophic ring failure.
The photograph of the deformed ring is presented below:
Materials and Methods
The patient's notes and X-rays were reviewed and a macroscopic examination of the deformed ring was performed. Mechanical tests of different Taylor Spatial frame constructs were performed in an attempt to simulate the deformity that was clinically observed. Different constructs of TSF of different ring sizes were fixed to polyurethane cylinders simulating bone, were mechanically tested to failure and load/deflection curves were produced.
Results
Macroscopically the ring looked otherwise normal. Gradual mechanical compression tests of Taylor Spatial frame constructs showed that ring deformation increased by increasing the ring diameter and by using jointed rather than full joints without a ring. The ring deformation observed clinically was reproduced at the lab by applying high loads on frame constructs composed of large diameter jointed rings not rigidly fixed to bone.
Conclusions
Taylor Spatial frame ring failure during treatment is a serious complication that has not been described in the literature. Possible causes are discussed. Clinicians are advised to use the smaller possible diameter rings. Where large diameter rings are required, these rings should preferably be not jointed. Half rings when used should be carefully and securely joined together by the operating surgeon in order to make a complete ring.
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