We performed a systematic review and meta-analysis
of modern total ankle replacements (TARs) to determine the survivorship,
outcome, complications, radiological findings and range of movement,
in patients with end-stage osteoarthritis (OA) of the ankle who
undergo this procedure. We used the methodology of the Cochrane Collaboration,
which uses risk of bias profiling to assess the quality of papers
in favour of a domain-based approach. Continuous outcome scores
were pooled across studies using the generic inverse variance method
and the random-effects model was used to incorporate clinical and
methodological heterogeneity. We included 58 papers (7942 TARs)
with an interobserver reliability (Kappa) for selection, performance,
attrition, detection and reporting bias of between 0.83 and 0.98.
The overall survivorship was 89% at ten years with an annual failure
rate of 1.2% (95% confidence interval (CI) 0.7 to 1.6). The mean
American Orthopaedic Foot and Ankle Society score changed from 40 (95%
CI 36 to 43) pre-operatively to 80 (95% CI 76 to 84) at a mean follow-up
of 8.2 years (7 to 10) (p <
0.01). Radiolucencies were identified
in up to 23% of TARs after a mean of 4.4 years (2.3 to 9.6). The
mean total range of movement improved from 23° (95% CI 19 to 26)
to 34° (95% CI 26 to 41) (p = 0.01). Our study demonstrates that TAR has a positive impact on patients’
lives, with benefits lasting ten years, as judged by improvement
in pain and function, as well as improved gait and increased range
of movement. However, the quality of evidence is weak and fraught
with biases and high quality randomised controlled trials are required
to compare TAR with other forms of treatment such as fusion. Cite this article:
We compared the performance of uncemented trabecular metal tibial components in total knee replacement with that of cemented tibial components in patients younger than 60 years over two years using radiostereophotogrammetric analysis (RSA). A total of 22 consecutive patients (mean age 53 years, 33 to 59, 26 knees) received an uncemented NexGen trabecular metal cruciate-retaining monobloc tibial component and 19 (mean 53 years, 44 to 59, 21 knees) a cemented NexGen Option cruciate-retaining modular tibial component. All the trabecular metal components migrated during the initial three months and then stabilised. The exception was external rotation, which did not stabilise until 12 months. Unlike conventional metal-backed implants which displayed a tilting migration comprising subsidence and lift-off from the tibial tray, most of the trabecular metal components showed subsidence only, probably due to the elasticity of the implant. This pattern of subsidence is regarded as being beneficial for uncemented fixation.
