Chondrodiatasis in a patient with spondyloepimetaphyseal dysplasia using the Ilizarov technique: successful correction of an angular deformity with ensuing ossification of a large metaphyseal lesion

Abstract

Case historyThe patient was born at term following a normal pregnancy. His family history was unremarkable, and all his anthropometric parameters at birth were normal, except for a height of 43 cm (below 3rd percentile). Psychomotor development was adequate for his age. Chromosomal and metabolic studies were normal. By the age of 5 years, extensive involvement of the proximal femora was evident, and the diagnosis of spondyloepimetaphyseal dysplasia was made. He underwent bilateral valgus derotational osteotomies of the proximal femur for the correction of severe coxa vara deformities.At 11 years of age he developed a progressive left genu recurvatum deformity of 30° (Fig. 1). Radiographs showed anterior collapse of the tibial plateau into a large, cystic radiolucent lesion of the proximal tibial metaphysis which lay adjacent to the physis and measured 3.0×3.2×1.2 cm (Fig. 2). It was decided to correct the deformity by slow, controlled distraction through the physis. An Ilizarov external fixator was percutaneously applied to the left tibia, and no osteotomy was performed. One ring was secured to the proximal tibial epiphysis oriented in the plane of the tibial plateau. The distal rings were secured to the proximal tibial shaft and then crosslinked. The proximal ring was connected to the distal ones by three hinged distracting rods, two anterior and one posterior. The distraction rate did not exceed 0.5 mm/day (Figs. 3 and 4). A simultaneous lengthening of 3 cm was performed to compensate for the expected growth arrest of the proximal tibial metaphysis following the physeal distraction. The fixator was removed 10 months after its application. The patient then remained in a cast for a period of 6 weeks followed by a brace for an additional 9 weeks. The only complication that occurred during treatment was a pin-tract infection which was successfully treated with oral antibiotics. Clinical and radiologic examination at the end of treatment and 8 months after showed complete correction of the angular deformity. The patient maintained a full range of motion of the affected knee. Surprisingly, the large metaphyseal cystic lesion ossified completely. At the latest follow-up, 3 years after the end of treatment, the patient was functioning well. The 3-cm lengthening performed was judicious, as there was no limb-length discrepancy at the end of growth (Figs. 5 and 6).