Lower limb lengthening and deformity correction in polyostotic fibrous dysplasia using external fixation and flexible intramedullary nailing.

The study describes preliminary experience of the use of external fixators for limb lengthening and deformity correction in combination with flexible intramedullary nailing in management of polyostotic fibrous dysplasia. PATIENTS AND METHODS: The retrospective study included 8 patients (mean age 11.6 ± 3.38 years; range 7-17 years) with polyostotic fibrous dysplasia operated on using external circular frame and flexible intramedullary nailing. Mean follow-up was 2.6 years. Surgical technique consisted of percutaneous osteotomy of a segment and application of circular external frame. The intramedullary nailing was done using two bent nails. Hydroxyapatite-coated nails were applied in three patients; five patients had titanium nails. Amount of lengthening (cm and %), amount of deformity correction, duration of external fixator use, index of external fixation, "nail/medullary canal at narrowest site" ratio, "nail-medullary canal at osteotomy site" ratio were analyzed. Results and complications were assessed according to Lascombes's classification. RESULTS: The mean amount of lengthening was 4.5 cm (or 13.7 ± 6.0% per segment). This gave a mean external fixation index of 32.5 ± 13.97 days/cm. The mean ratio of IM nail diameter/medullary canal diameter at the narrowest site was 0.22 ± 0.07 (range, 0.125-0.3 mm). No migration of IM nails into medullary canal were noticed. But in one case there was external migration of Ti-nail. In a year after frame removal, the results of treatment were classified as grade I in 7 cases and IIb in one case.At the latest follow-up control, mechanical axis deviation was found within normal limits in six patients. Two patients had excessive MAD of 11 and 28 mm. In the first case a partial varus deformity recurrence occurred at middle shaft site where a large dysplastic zone was presented. In the second case, a specific shepherd's crook deformity developed and caused excessive MAD. Mean lower limb length discrepancy varied from 1 to 15 mm. CONCLUSION: There are advantages of using elastic intramedullary nailing and external fixation in the treatment of limb length discrepancy and deformity of long bones in patients with PFD. This strategy ensures reduced external fixation time and high accuracy of alignment. Intramedullary nails left in situ, especially nails with HA-coating, seem to prevent deformity recurrence and stimulate remodeling in dysplastic fibrous zones.

Results of deformity correction in children with X-linked hereditary hypophosphatemic rickets by external fixation or combined technique.

BACKGROUND: The operative procedures to correct multiplanar bone deformities may be indicated for prevention of secondary orthopaedic complications in children with X-linked hereditary hypophosphatemic rickets (XHPR). Different problems related to surgical correction were reported: increased rate of non-union, delayed union, recurrent deformity, deep intramedullary infection, refracture, nerve palsy, and pin tract infection. The aim of this retrospective study was comparison of results of correction in children with XHPR who underwent the treatment with either the Ilizarov device alone or a combined technique: the Ilizarov fixator with flexible intramedullary nailing (FIN) with hydroxyapatite bioactive coating and FIN. MATERIAL AND METHODS: We retrospectively analysed 47 cases (children of age under 14 years) affected by XHPR. Simultaneous deformity correction in femur and tibia was performed with the Ilizarov device (group I) or the combined method (group II). This article is based on the results of a historical comparative retrospective study from the same institution. RESULTS: The duration of external fixation is noted to be shorter applying the combined technique: 124.7 days (group I) vs 87.4 days (group II). In both groups deformity correction was achieved with a proper alignment. Nevertheless, while a child continues to grow during long-term follow-up, deviations of the mechanic axis from the centre of the knee joint have been developing again and values of mLDFA, mMPTA have become pathologic in the most of the cases. In group I location of a newly developed deformity resembled a pre-operative one, whereby both diaphyseal and metaphyseal parts were deformed. In group II in all the cases an apex of deformity was located in distal metadiaphyseal zone of the femur and proximal metadiaphyseal zone of the tibia. It is important to note that all of those in group II were out of the zone of the intramedullary nail. CONCLUSION: Simultaneous correction of femoral and tibial deformities by means of circular external fixators is preferable. Application of a combined osteosynthesis allows to considerably reduce the duration of external fixation and decrease the number of complications. There were no recurrent deformities in parts of bone reinforced by intramedullary nails.

Prevention of recurrence of tibia and ankle deformities after bone lengthening in children with type II fibular hemimelia.

PURPOSE: This study aimed to evaluate development of the tibia after Ilizarov lengthening and deformity correction depending on whether or not the simultaneous resection of fibular anlage was performed in children with fibular aplasia type II, who did not undergo early surgery. METHODS: The study analyses results of reconstructive treatment in 38 children at the age of over four years. Two groups of children are compared: bifocal tibial lengthening with the Ilizarov device (group I) and bifocal lengthening associated with resection of the fibular anlage (group II). The results were estimated at 12 months and in the long-term exceeding three years. RESULTS: Radiological data of measurement of the anatomical lateral distal tibial angle (aLDTA) show surgical correction of deformities achieved in both groups. During the further limb growth a tendency to normalisation of the aLDTA was observed only in the group II. Quick relapse of the angular deformities of the tibial shaft in the first group occurred mainly during further growth of the limb regardless of complete correction at the time of treatment. On the other hand, there were no recurrences of diaphyseal deformities in the group II. CONCLUSIONS: In children with congenital fibular deficiency of type II at the age of four years, the bone lengthening and deformity correction should be associated with fibular anlage resection. That approach improves conditions for distal tibia development and prevents or decreases significantly the recurrence of deformities of the tibia and ankle joint in long-term follow-up.