Aim. To assess the efficacy of combined medical and surgical management in obtaining normal lower limb mechanical alignment in a patient cohort with genotypically similar hypophosphataemic rickets. Methods. A notes and radiograph audit was performed of all patients attending our institution with hypophosphataemic rickets: a subset with PHEX gene anomalies was studied further. Lower limb radiographs were assessed at two points during childhood and note made of treatment start, compliance; indication, timing and result of surgery. Standing leg alignment radiographs were measured at skeletal maturity or at latest review. Results. 35 patients (16 females, 18 skeletally mature) were identified. 10 commenced treatment at <12m. 11 patients (5 female) underwent 24 surgical procedures (13 for varus deformities). Surgery was bilateral in 10/11 patients. 5/14 osteotomies were performed after skeletal maturity. Malalignment was common: with NSA (neck-shaft angle) abnormalities in 20%, abnormal angles at distal femur and proximal tibia in 58% and 60% respectively and ankle abnormalities in 24%, prior to surgery. Surgical management led to normal mechanical alignment at skeletal maturity. At latest review, no patient had a leg length difference. 40% of non-operated, skeletally immature limbs have significant malalignment despite medical therapy. There was no statistical relationship between treatment onset and need for surgical correction. The relationship between non-compliance with medical treatment and surgical intervention was confounded by the changing emphasis on preferred method of surgical correction from osteotomy to guided growth. Conclusion. Even when medical treatment is commenced promptly and adhered to, significant lower limb malalignment can occur requiring surgical correction. Guided growth principles allow early deformity correction. Significance. Lower limb malalignment should not be considered a failure of medical treatment but more a consequence of the disease process. Earlier surgical intervention may encourage a more normal pattern of growth

Distal femoral physeal fractures in children have a high incidence of physeal arrest, occurring in a mean of 40% of cases. The underlying nature of the distal femoral physis may be the primary cause, but other factors have been postulated to contribute to the formation of a physeal bar. The purpose of this study was to assess the significance of contributing factors to physeal bar formation, in particular the use of percutaneous pins across the physis.

We reviewed 55 patients with a median age of ten years (3 to 13), who had sustained displaced distal femoral physeal fractures. Most (40 of 55) were treated with percutaneous pinning after reduction, four were treated with screws and 11 with plaster. A total of 40 patients were assessed clinically and radiologically after skeletal maturity or at the time of formation of a bar. The remaining 15 were followed up for a minimum of two years.

Formation of a physeal bar occurred in 12 (21.8%) patients, with the rate rising to 30.6% in patients with high-energy injuries compared with 5.3% in those with low-energy injuries. There was a significant trend for physeal arrest according to increasing severity using the Salter-Harris classification. Percutaneous smooth pins across the physis were not statistically associated with growth arrest.