We compared revision and mortality rates of 4668
patients undergoing primary total hip and knee replacement between
1989 and 2007 at a University Hospital in New Zealand. The mean
age at the time of surgery was 69 years (16 to 100). A total of
1175 patients (25%) had died at follow-up at a mean of ten years
post-operatively. The mean age of those who died within ten years
of surgery was 74.4 years (29 to 97) at time of surgery. No change
in comorbidity score or age of the patients receiving joint replacement
was noted during the study period. No association of revision or
death could be proven with higher comorbidity scoring, grade of
surgeon, or patient gender. We found that patients younger than 50 years at the time of surgery
have a greater chance of requiring a revision than of dying, those
around 58 years of age have a 50:50 chance of needing a revision,
and in those older than 62 years the prosthesis will normally outlast
the patient. Patients over 77 years old have a greater than 90%
chance of dying than requiring a revision whereas those around 47
years are on average twice as likely to require a revision than
die. This information can be used to rationalise the need for long-term
surveillance and during the informed consent process.
We reviewed the results at nine to 13 years of 125 total hip replacements in 113 patients using the monoblock uncemented Morscher press-fit acetabular component. The mean age at the time of operation was 56.9 years (36 to 74). The mean clinical follow-up was 11 years (9.7 to 13.5) and the mean radiological follow-up was 9.4 years (7.7 to 13.1). Three hips were revised, one immediately for instability, one for excessive wear and one for deep infection. No revisions were required for aseptic loosening. A total of eight hips (7.0%) had osteolytic lesions greater than 1 cm, in four around the acetabular component (3.5%). One required bone grafting behind a well-fixed implant. The mean wear rate was 0.11 mm/year (0.06 to 0.78) and was significantly higher in components with a steeper abduction angle. Kaplan-Meier survival curves at 13 years showed survival of 96.8% (95% confidence interval 90.2 to 99.0) for revision for any cause and of 95.7% (95% confidence interval 88.6 to 98.4) for any acetabular re-operation.