Abstract
Extensor mechanism disruption following total knee arthroplasty (TKA) is a devastating
complication that causes high failure rates. There is controversy on what is the best
way to do an extensor mechanism reconstruction. This study aims to compare both allograft
and synthetic reconstructive techniques for success, reoperation, and infection rates
and functional outcomes. The search on PubMed, MEDLINE, Embase, BIOSIS, and Cochrane
databases was performed on March 15, 2019, using the following keyword groups: (1)
“extensor mechanism” and “total knee arthroplasty,” (2) “extensor mechanism” and “knee
arthroplasty,” (3) “extensor mechanism” and “revision total knee arthroplasty,” and
(4) “extensor mechanism” and “revision knee arthroplasty”. Only studies on extensor
mechanism disruption after TKA that included sufficient data to compare these two
surgical techniques were included. Meta-analysis was performed with random effect
model using the DerSimonian–Laird method. Thirty studies were included. The overall
success rate of the reconstruction was 73.3% (95% confidence interval [CI]: 0. 651,
0.814). The success rate of allograft (72.8%, 95% CI: 0.626, 0.829) was not significantly
different from synthetic material (78%, 95% CI: 0.707, 0.852, p = 0.416). There was no significant difference in revision rates between allograft
(14.2%, 95% CI: 0.095, 0.189) and synthetic material (16%, 95% CI: 0.096, 0.223, p = 0.657). The overall relative risk of infection was 4.301 (95% CI: 1.885, 9.810).
There was no significant difference in relative risk of infection between allograft
(3.886, 95% CI: 1.269, 11.903) and synthetic material (4.851, 95% CI: 1.433, 16.419,
p = 0.793). No statistically significant difference was found in mean postoperative
Knee Society score (73.109 [95% CI: 67.296, 78.922] vs. 72.679 [95% CI: 69.184, 76.173],
p = 0.901) between allograft and mesh reconstruction groups. There were no significant
differences in overall failures, infections, functional outcomes, or revision reconstructions
between allograft and synthetic material extensor mechanism reconstructions. Our results
demonstrate the difficulty in treating this serious injury, independent of technique,
as well as the significant risk for overall failure and infection.
Keywords
extensor mechanism - knee arthroplasty - allograft - mesh - replacement