Mega prosthetic distal femoral arthroplasty for non-tumour indications: does the indication affect the functional outcome and survivorship?
OBJECTIVE
To report the functional outcome, implant survival, and patient mortality after mega prosthetic distal femoral arthroplasty according to the surgical indication.


METHODS
A prospective database was compiled for 45 consecutive patients undergoing distal femoral arthroplasty, of which 26 had fractures of the distal femur (group 1) and 19 underwent revision of a total knee arthroplasty (group 2). There were 17 males and 28 females with a median age of 74.5 years. Short form (SF)-12 scores were recorded pre-operatively (before the fracture or revision) and 1 year post-operatively, at which point a Toronto Extremity Salvage Score (TESS) was also obtained. Length of hospital stay and return to place of domicile was obtained from the hospital database. Mortality status was obtained from the General Register Office for Scotland. No patient was lost to follow-up.


RESULTS
The 1-year physical (52.4) and mental (63.4) components of the SF-12 score and the TESS (70.5 %) did not significantly differ between the groups (n.s.). The fracture group, however, had a longer length of stay (8 vs. 19 days, p = 0.001) and were also less likely to return to their original domicile (odds ratio 9.5, p = 0.02). The overall implant survival rate was 85 % at 5 years, which was worse for the fracture group (80 vs. 90 %, n.s.). The 5-year mortality rate for the revision group was 17 %, whereas the fracture group demonstrated a greater mortality rate of 43 % (n.s.).


CONCLUSIONS
The functional outcome, revision rate, and mortality of patients undergoing distal femoral arthroplasty for non-tumour reasons are not influenced by indication, but patients undergoing surgery for fractures of the distal femur have a longer length of stay and are less likely to return home. Distal femoral arthroplasty should be considered as a management option for non-tumour salvage procedures of the distal femur.


METHODS
Retrospective comparative study, Level III.
Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK. nickclement@doctors.org.uk.
N D
ND
Clement
University of Edinburgh, Edinburgh, UK.
D
D
MacDonald
Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
M
M
Moran
Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
R
R
Burnett
Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
C R
CR
Howie
Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
J T
JT
Patton
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005264:Femoral Fractures / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D012606:Scotland / Q000453:epidemiology; D015996:Survival Rate / Q000639:trends