Abstract
Background
Endoprosthetic reconstruction is an established method of treatment for primary bone tumours in children. Traditionally these were implanted with cemented intramedullary fixation. Hydroxyapatite collars at the shoulder of the implant are now standard on all extremity endoprostheses, but older cases were implanted without collars. Uncemented intramedullary fixation with hydroxyapatite collars has also been used in an attempt to reduce the incidence of problems such as aseptic loosening. Currently there are various indications that dictate which method is used.
Aims
To establish long term survivorship of cemented versus uncemented endoprosthesis in paediatric patients with primary bone tumours.
Methods
This was a retrospective study of 441 endoprostheses implanted in 367 consecutive patients aged 18 years or less, between 1973 and 2005. This included the use of case notes, hospital databases and a radiological review. Information obtained included patient demographics, indications for surgery, anatomical distribution and type of implants, complications and survivorship.
Results
Mean age was 13.9 (range 3 - 38). 210 patients were male, 157 were female. There were 364 primaries and 77 revision implants. 161 extendable and 280 definitive prostheses. 282 patients had osteosarcoma, 54 had Ewing's sarcoma and 28 had other diagnoses. Commonest sites included 197 distal femoral replacements, 85 proximal tibial implants and 57 were in the upper limb. Kaplan-Meier survival analysis was used to compare anatomical sites and method of fixation. Upper limb implants had the best long term survival. Failure rates for distal femoral replacements were compared for cemented fixation (21.7% due to aseptic loosening) with cement plus hydroxyapatite collars (3.1%) and uncemented implants with hydroxyapatite collars (6.2%).
Conclusions
In the distal femur cemented fixation with hydroxyapatite collars gave the best survivorship in definitive primary prostheses. Uncemented fixation with hydroxyapatite collars gave the best survivorship in extendable prostheses. Cemented fixation without hydroxyapatite gave the worst survivorship.
