The aim of the study was to review the effectiveness of rigid IM nailing in stabilisation and deformity correction of lower limb long bones in adolescents with metabolic bone disease which to our knowledge has not been studied before.

Medical records and radiographs were retrospectively reviewed looking at indications, deformity correction, number of osteotomies-if needed, bone healing, time to healing and incidence of complications.

Between Aug 2010 and Mar 2015 fifteen patients (24 segments) had rigid IM nailing. Ten patients had Osteogenesis Imperfecta, four with McCune Albright syndrome and one with hypophosphatemic rickets. 22 femora and two tibiae were IM nailed. The mean age of the patients was 13.1 (9.6–16.75 years). Eleven out 24 segments were previously rodded. Eight segments were for acute fractures. 13 bones had significant deformities requiring corrective osteotomies. One patient had previous fracture non union.

All patients were allowed to partial weight bear immediately postoperatively and were fully mobile six weeks following surgery. Mean follow up was 24 months (3–51 months) post-operatively. All deformities were corrected. All fractures and osteotomies radiologically united.

Mean radiological union time was 5.5 months (6 weeks – 11 months). Patients with acute fractures had mean radiological union time of 4 months. Patients who had osteotomies had a mean radiological union time of 7.1 months. The patient with previous non union had BMP at the same time and radiologically healed in 10 months. Two patients had persistent bisphosphonate osteotomy lines but were asymptomatic. One patient had removal of a prominent distal locking screw and one had persistent Trendelenburg gait.

Rigid intramedullary nailing is effective in stabilisation and deformity correction of long bones in adolescent patients with brittle bone disease. The technique has a low complication rate. We recommend the use of this technique in paediatric limb reconstruction in managing metabolic bone conditions.

Femoral head deformity can be a devastating outcome in a small percentage of patients with Perthes' disease. Deformities usually start during the fragmentation stage. In this study, we aimed to determine the effects of Vitamin D deficiency on the natural history of Perthes' disease.

Patients with Perthes' disease and Vitamin D deficiency presenting to our unit in the last 3 years were identified. All X-rays were reviewed retrospectively to determine the duration of the fragmentation and ossification stages. Treatment methods were obtained from the notes. Late presenters (i.e. after fragmentation stage) were excluded.

In our unit, Vitamin D deficiency is diagnosed if levels <72 nmol/L. Fifteen patients (17 hips) with Perthes' disease were found to be Vitamin D deficient. Levels ranged from (18–71 nmol/L). The mean length of the fragmentation stage was 15.7 months which is significantly higher than quoted literature figures (8 months). Ossification stage duration was 18.8 months which was comparable to quoted figures. However, patients with severe Vitamin D deficiency (< 52 nmol/L) were found to have longer ossification stage (20.6 months) compared with patients with mild deficiency (52–72 nmol/L) (16.4 months). Seven out of 16 patients (44%) required surgical containment which is significantly higher than the usually low rates of surgical intervention.

The critical fragmentation stage in Vitamin D deficiency is significantly longer putting the femoral head at higher risk of deformity and extrusion. This leads to higher rates of surgical containment. Also the severity of Vitamin D deficiency might be an important determinant of the period of time required for ossification and healing.

Vitamin D level is an important prognostic factor and must be measured in all patients with Perthes' disease. Prescribing Vitamin D supplements is advisable in this group of patients. However, the effects of these supplements on the course of the disease requires further research.

Level of evidence: III