In skeletally immature patients, resection of
bone tumours and reconstruction of the lower limb often results
in leg-length discrepancy. The Stanmore non-invasive extendible
endoprosthesis, which uses electromagnetic induction, allows post-operative
lengthening without anaesthesia. Between 2002 and 2009, 55 children
with a mean age of 11.4 years (5 to 16) underwent reconstruction
with this prosthesis; ten patients (18.2%) died of disseminated
disease and one child underwent amputation due to infection. We
reviewed 44 patients after a mean follow-up of 41.2 months (22 to
104). The mean Musculoskeletal Tumor Society score was 24.7 (8 to
30) and the Toronto Extremity Salvage score was 92.3% (55.2% to
99.0%). There was no local recurrence of tumour. Complications developed
in 16 patients (29.1%) and ten (18.2%) underwent revision. The mean length gained per patient was 38.6 mm (3.5 to 161.5),
requiring a mean of 11.3 extensions (1 to 40), and ten component
exchanges were performed in nine patients (16.4%) after attaining
the maximum lengthening capacity of the implant. There were 11 patients
(20%) who were skeletally mature at follow-up, ten of whom had equal
leg lengths and nine had a full range of movement of the hip and
knee. This is the largest reported series using non-invasive extendible
endoprostheses after excision of primary bone tumours in skeletally
immature patients. The technique produces a good functional outcome,
with prevention of limb-length discrepancy at skeletal maturity.
Aims
Patients and Methods
