This study aims to evaluate the development of deformity in patients with hypophosphataemic rickets and the evolution of the orthopaedic management thereof. Fifty-four patients had undergone treatment for hypophosphataemic rickets at our institution since 1995. Clinical records for all patients were obtained. Forty-one patients had long leg radiographs available that were analysed using Traumacad™ software. Statistical analysis was performed using SPSS 23 (SPSS Inc., Chicago, Illinois, USA). Of the 41 patients, 18 (43%) had no radiographic deformity. 20 have undergone bilateral lower limb surgery for persistent deformity (Mechanical Axis ≥ Zone 2). A further 3 patients are awaiting surgery. Six patients (12 limbs, 14 segments) had osteotomies and internal fixation as primary intervention: only one limb developed recurrent deformity. There were no major complications. Fourteen patients (28 limbs) had 8-plates (Orthofix, Verona) applied. In 5 limbs correction is on-going. Neutral alignment (central Zone 1) was achieved in 14/20 (70%) patients. Two patients required osteotomy and external fixation for resistant deformity. The mean rate of angular correction following 8-plate application was 0.3 and 0.7 degrees/month for the tibia and femur respectively. The mean age at 8-plate insertion was 10.25y (5–15y). Patients with more than 3 years of growth remaining responded significantly better than older patients (Fisher Exact Test, p=0.024). Guided growth was more successful in correcting valgus deformity than varus deformity (Fisher Exact Test, p=0.04). In the younger patients, diaphyseal deformity corrected as the mechanical axis improved at the rate of 0.2 and 0.7 degrees /month for the tibial and femoral shafts. Serum phosphate and alkaline phosphatase levels did not affect response to surgery or complication rate. Guided growth by means of 8-plates is a successful in addressing deformity in hypophosphataemic rickets. Surgery is best performed in patients with more than 3 years of growth remaining

Background. Unicameral bone cysts (UBCs) are difficult to treat and have a high recurrence rate. Their pathogenesis is unknown making targeted therapies difficult. Attributed causes include venous and interstitial fluid obstruction, oxygen free radicals, lysosomal enzymes, prostaglandins and genetic factors. Skeletal stem cells (SSCs) are osteoblast precursors critical to bone formation and cyst fluid may influence their growth, however the association between SSCs and cyst fluid has never been investigated. Aim. To investigate the effect of UBC fluid on SSC growth. Methods. Fluid was aspirated from a UBC in the proximal femur of a nine year old boy and centrifuged to isolate the acellular supernatant. SSCs were harvested from bone marrow of a haematologically normal adult and cultured with graded concentrations of cyst fluid in culture media (0,10,25,50%). Cell growth was assessed by alkaline phosphatase staining, and cytokine levels in the fluid were measured. Results. High levels of cytokines known to be chemo-attractive for cells of the of macrophage-monocyte lineage were found, including Macrophage Chemotactic Protein-1 (1853pg/ml), Monokine Induced by γ-interferon (656pg/ml), Macrophage Inflammatory Protein (MIP)-1α (401pg/ml) and MIP-1β (34pg/ml) suggesting a role of osteoclasts in UBC pathogenesis. Furthermore, SSC growth in vitro was reduced in cyst fluid in a concentration dependent manner. Conclusion. This is the first time altered SSC and osteoprogenitor function has been associated with the fluid of a UBC. A negative effect on osteogenesis was demonstrated, the precise mechanisms of which are under investigation, and macrophage-monocyte chemokines suggest high osteoclast activity. This study has indicated a role of the cyst fluid in limiting osteogenesis and bone turnover, which may explain the high failure rate for current interventions. More patients are needed to validate these findings

Slipped capital femoral epiphysis (SCFE) is uncommon in India and we routinely look for associated metabolic or endocrine abnormalities. In this study we investigated a possible association between vitamin D deficiency and SCFE. All children presenting with SCFE during the study period had their 25-hydroxyvitamin D levels measured as part of an overall metabolic, renal and endocrine status evaluation, which included measurement of body mass index (BMI). Vitamin D status was compared with age-, gender- and habitat-matched controls with acute trauma or sepsis presenting to our emergency department.

A total of 15 children (12 boys and three girls) with a mean age of 13 years (sd 1.81; 10 to 16) presented for treatment for SCFE during a two-year period beginning in January 2010. Renal and thyroid function was within the normal range in all cases. The mean BMI was 24.9 kg/m² (17.0 to 33.8), which was significantly higher than that of the controls (p = 0.006). There was a statistically significant difference between the mean values of 25-hydroxyvitamin D in the children with SCFE and the controls (11.78 ng/ml (sd 5.4) versus 27.06 ng/ml (sd 5.53), respectively; p < 0.001). We concluded that, along with high BMI, there is a significant association of vitamin D deficiency and SCFE in India.

Cite this article: Bone Joint J 2013;95-B:851–4.