We present the results of the surgical correction of lower-limb deformities caused by metabolic bone disease. Our series consisted of 17 patients with a diagnosis of hypophosphataemic rickets and two with renal osteodystrophy; their mean age was 25.6 years (14 to 57). In all, 43 lower-limb segments (27 femora and 16 tibiae) were osteotomised and the deformity corrected using a monolateral external fixator. The segment was then stabilised with locked intramedullary nailing. In addition, six femora in three patients were subsequently lengthened by distraction osteogenesis. The mean follow-up was 60 months (18 to 120). The frontal alignment parameters (the mechanical axis deviation, the lateral distal femoral angle and the medial proximal tibial angle) and the sagittal alignment parameters (the posterior distal femoral angle and the posterior proximal tibial angle) improved post-operatively. The external fixator was removed either at the end of surgery or at the end of the lengthening period, allowing for early mobilisation and weight-bearing. We encountered five problems and four obstacles in the programme of treatment. The use of intramedullary nails prevented recurrence of deformity and refracture

The aim of this pilot study was to evaluate the accuracy of two different methods of navigated retrograde drilling of talar lesions. Artificial osteochondral talar lesions were created in 14 cadaver lower limbs. Two methods of navigated drilling were evaluated by one examiner. Navigated Iso-C^3D was used in seven cadavers and 2D fluoroscopy-based navigation in the remaining seven. Of 14 talar lesions, 12 were successfully targeted by navigated drilling. In both cases of inaccurate targeting the 2D fluoroscopy-based navigation was used, missing lesions by 3 mm and 5 mm, respectively. The mean radiation time was increased using Iso-C^3D navigation (23 s; 22 to 24) compared with 2D fluoroscopy-based navigation (14 s, 11 to 17).