Endoprosthetic replacement of the distal femur for bone tumours: long-term results.
We investigated whether improvements in design have altered the outcome for patients undergoing endoprosthetic replacement of the distal femur after resection of a tumour. Survival of the implant and 'servicing' procedures have been documented using a prospective database, review of the design of the implant and case records. In total, 335 patients underwent a distal femoral replacement, 162 having a fixed-hinge design and 173 a rotating-hinge. The median age of the patients was 24 years (interquartile range 17 to 48). A total of 192 patients remained alive with a mean follow-up of 12 years (5 to 30). The risk of revision for any reason was 17% at five years, 33% at ten years and 58% at 20 years. Aseptic loosening was the main reason for revision of the fixed-hinge knees while infection and fracture of the stem were the most common for the rotating-hinge implant. The risk of revision for aseptic loosening was 35% at ten years with the fixed-hinge knee, which has, however, been replaced by the rotating-hinge knee with a hydroxyapatite collar. The overall risk of revision for any reason fell by 52% when the rotating-hinge implant was used. Improvements in the design of distal femoral endoprostheses have significantly decreased the need for revision operations, but infection remains a serious problem. We believe that a cemented, rotating-hinge prosthesis with a hydroxyapatite collar offers the best chance of long-term survival of the prosthesis.
Myers
G J C
GJ
he Royal Orthopaedic Hospital, Bristol Road South, Birmingham B31 2AP, UK.
Abudu
A T
AT
Carter
S R
SR
Tillman
R M
RM
Grimer
R J
RJ
D000293:Adolescent; D000328:Adult; D005260:Female; D005266:Femoral Neoplasms / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D023821:Limb Salvage / Q000379:methods; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000209:etiology / Q000601:surgery; D012086:Reoperation; D016019:Survival Analysis; D016896:Treatment Outcome