Aims

Perthes’ disease is a condition which leads to necrosis of the femoral head. It is most commonly reported in children aged four to nine years, with recent statistics suggesting it affects around five per 100,000 children in the UK. Current treatment for the condition aims to maintain the best possible environment for the disease process to run its natural course. Management typically includes physiotherapy with or without surgical intervention. Physiotherapy intervention often will include strengthening/stretching programmes, exercise/activity advice, and, in some centres, will include intervention, such as hydrotherapy. There is significant variation in care with no consensus on which treatment option is best. The importance of work in this area has been demonstrated by the British Society for Children’s Orthopaedic Surgery through the James Lind Alliance’s prioritization of work to determine/identify surgical versus non-surgical management of Perthes’ disease. It was identified as the fourth-highest priority for paediatric lower limb surgery research in 2018.

We report a retrospective review of 62 consecutive patients who had a vascularised fibular transfer to reconstruct a large skeletal defect. We were particularly interested in the bone dynamics of the vascularised graft, since fractures occurred in 25% of the cases at an average time of eight months after surgery. Hypertrophy was more common when the limb was mechanically loaded; it was enhanced where the graft was not bypassed by internal fixation. The length of the graft and the use of additional bone graft material had no influence on the incidence of stress fracture or on hypertrophy. We conclude that a vascularised graft should be protected against fatigue fracture during the first year, and that a gradual increase in mechanical loading will enhance remodelling and hypertrophy.

In 65 mature Wistar rats a Kirschner wire was introduced into the medullary cavity of each femur. A closed transverse mid-shaft fracture of one femur was produced by a three-point bending technique. Subsequently the mechanical characteristics of the healing fracture, including the torque and angle of twist required to take the callus to its yield point and to ultimate failure, were compared with those for the opposite femur of each rat. Controls were killed in groups at two, three, four, five and seven weeks. Test animals were given bovine growth hormone in a daily dose of five milligrams before being killed in groups at two, three and four weeks. A significant increase in torque index was found in the two-week group of test animals but not in subsequent groups. No evidence was found that growth hormone given alone could produce an overall shortening of the healing time in fresh fractures.