Abstract
The aim of this study is to evaluate the efficiency of the Sheffield Ring Fixator (SRF) in the management of tibial deformity.
Tibial deformity correction is challenging and requires an efficient system with strong bony fixation.Progressive correction is usually necessary due to the low compliance of the anatomical compartments. The SRF provides an effective solution, employing a combination of wire and screw fixation for metaphyseal corrections and all screw fixation for diaphyseal corrections.
We reviewed a consecutive series of 50 patients with tibial deformity treated by progressive correction using the SRF between 1997 and 2000. The mean age was 33 years (range 18 to 65). Thirty nine cases were due to post-traumatic deformity and eleven as sequelae of childhood disease. Cases were analysed to ascertain the degree of deformity, treatment time, final outcome in terms of the accuracy of correction of deformity, and incidence of complications.
All patients had significant angular deformity and 12 had a rotational deformity. 21 patients had clinically significant shortening. The mean deformities were: varus 10.5, valgus 13, posterior 11.8, anterior 20.6 (giving a mean oblique plane deformity of 24° ) rotation 17° and 26mm of shortening. Full correction was achieved in 45 of the 50 cases: Three patients had residual angular deformities of 5,7 and 10 degrees and two had residual shortening (15mm& 5mm). Satisfactory bone formation occurred in all cases. There were no significant complications. The mean correction time was dependent on whether or not lengthening had been performed (72 and 53 days respectively). From this study the correction time can be estimated as 2 days per degree plus an extra 0.5 days per degree for every centimetre of length to be gained.
A knowledge of the efficiency of the system will enable estimation of treatment times to be made thereby facilitating the setting of goals for both patient and surgeon. Correction and total treatment times were satisfactory suggesting that the fixation system was both stable and yet sufficiently elastic to permit good bone healing. Even when the rotation translation systems were used prescribed movements led to satisfactory corrections suggesting few if any losses in the system. The SRF provides a strong and efficient system for the accurate and controlled correction of tibial deformities.
The abstracts were prepared by Mr Richard Buxton. Correspondence should be addressed to him at Bankton Cottage, 21 Bankton Park, Kingskettle, Cupar, Fife KY15 7PY, United Kingdom
