Reduction of the period of treatment for leg lengthening

Purpose of the study We assessed an adaptation of the Ilizarov method aimed at a considerable reduction in the period of treatment for leg lengthening in order to limit complications related to the duration of the external fi xation. This technique associates multiple segment lengthening, automatic h igh-frequency lengthening, and stimulation of bone regeneration by extempor aneous compression at the end of traction. Material and methods We analyzed 78 cases of automatic femur lengthening in 40 patients and simultaneous femur and tibia lengthening in 38 patients. T here were 51 men and 27 women, mean age 13.2 years (6 - 43 years). Mean len gth deficiency was 4.3 cm for the femur and 3.5 cm for the tibia. Femoral a nd/or tibial deformations were observed in 32 patients. Minimal follow-up w as 1.5 years. The automatic traction device was composed of the conventiona l Ilizarov fixator and complementary elements. Different assemblies were us ed depending on the associated deformations allowing their progressive corr ection. For 17 patients, radioimmunoassay of thyrocalcitonin and parathormo ne was performed to compare the time courses. Results Mean femoral lengthening achieved was 49 mm (8.5 to 20%). Mean tibi al lengthening was 42 mm (7.2 to 18.8%). The consolidation index was 18.1 t o 21.3 days/cm for single-segment lengthenings and 11.5 days/cm (mean) for two-segment lengthenings (taking into account both the femoral and tibial g ain in length). The ideal moment of compression was 5.6 N/cm(2). Accelerati on of the bone repairing process was evidenced by activation of the osteotr op hormone system. According to the SOFCOT classification of complications (1990), 60 patients (76.9%) were in category 1, 15 (19.3%) in category II, and 3 (3.8%) in category III. Discussion Improvement of lengthening procedures with external fixators rem ains an important issue. Treatment periods are often long with consolidatio n indices for the femur ranging from 39.6 d/cm to 45 d/cm, which can lead t o many types of complications. Use of a high-frequency progressive lengthen ing procedure based on the Ilizarov method considerably reduces the rate of complications compared with progressive lengthening methods and has allowe d achieving more satisfactory results in a shorter treatment period. Conclusion Multiple-segment lengthening using an automatic lengthening proc edure set at 1 mm per day in four times provides an important reduction in the treatment delays since distraction is performed more rapidly and fewer steps are needed. Automatic high-frequency lengthening with the Ilizarov me thod provides optimal conditions for tissue regeneration: Treatment periods are shorter and anatomic and functional outcome is very satisfactory. Stim ulation by extemporaneous compression of the regeneration zone allows a red uction in the duration of consolidation. Shorter delays to consolidation he lp avoid device-related complications.