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.

Statement of Purpose

Our experience with Taylor Spatial Frame correction of complex foot deformities in children.

Persistent foot deformity in congenital talipes equinovarus is a challenge. Open surgery is associated with complications including difficulty in achieving acute corrections in stiff, scarred feet. Gradual correction using the Ilizarov circular frame has been described as an alternative and we present the experience using a computer assisted hexapod gradual frame correction with the Taylor Spatial Frame (TSF).

A retrospective audit of sequential patients treated by TSF was performed. Technique, outcome, complications and key learning points were recorded.

21 paediatric patients underwent 27 treatments with a Taylor Spatial frame for complex foot deformity correction. Average age 11 years with majority diagnosis of congenital talipes equinovarus. The deformities severity meant acute correction would result in either neurovascular or soft tissue compromise.

Plantigrade feet with good function was achieved in 22 feet. 3 feet were deemed as failures. 2 feet have residual deformity but acceptable function. According to Paley's classification, there were 4 complications, 7 obstacles and 35 difficulties (pin tract infection and pain management). Complications did contribute to poorer outcomes. The key learning points were: protection of the ankle joint and distal tibial physis; staged osteotomy reduces swelling and complication rates; and consideration of further procedures at frame removal is important. Finally a thorough preoperative counselling programme should be instituted and patients warned of the time commitment and high difficulty rates associated with treatment. Managing patient expectation with goals is as important as meticulous surgery.

Although complication rates were high, the majority of treatment goals were met, therefore the TSF is valid in the treatment of complex deformities in the foot. Most patients with severe deformity can achieve a plantigrade functional foot but residual stiffness and need for minor orthotics is almost universal.