Biomedical Engineering Reference
In-Depth Information
4)
Survivorship Analysis
Kaplan-Meier [99] Survivorship analysis was performed using several end points:
1.
Revision of any component for any reason.
2.
Poor Harris Hip Score.
3.
Radiographic loosening or clinical loosening of any component.
These analyses are shown in Figs. 5.21- 5.23 respectively).
Buechel-Pappas™ Total Hip Replacement
KAPLAN-MEIER SURVIVAL ESTIMATE
(E
n
dpoin
t:
Revision for any r
e
ason)
100
95.5%@11.2 years
90
80
70
60
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
TIME (Years)
Fig. 5.21
Kaplan-Myer Survivorship of Buechel-Pappas Total Hip Replacements with and
endpoint of revision for any reason
c)
Discussion
Long-term fixation and function, together with excellent wear resistance are the
prerequisites for successful total hip arthroplasty. Survivorship analysis, radiographic
analysis and clinical results are important outcome parameters by which orthopedic
surgeons can measure the success or failure of one hip replacement system over
another when used in similar patient populations. Primary hip replacement represents
the best clinical condition to evaluate a new or improved prosthesis since the
variables of major bone stock deficiencies associated with revision conditions are
minimized or eliminated by study design. In this study there were 130 primary total
hip replacements in 117 patients with minimum two year follow-up.
The femoral components used in this study were developed in response to the
potential stress shielding problem posed by the extensively coated AML device
developed by Emmett Lunceford in the late 1970's [75].
