Meta-analysis Comparing Allograft to Synthetic Reconstruction for Extensor Mechanism Disruption after Total Knee Arthroplasty

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.

A Modified Surgical Technique of Patellar Tendon Reconstruction in Total Knee Arthroplasty Using Achilles Tendon Allograft

“…Hence, the extensor mechanism composite graft is typically used in patients where the patella is absent or insufficient [ 14 ]. Risk of infection also presents a concern in allograft reconstructions with reviews showing up to a 3.8% risk of postoperative infections [ 15 ].…”

“…Meta-analysis such as that by Deren et al. shows comparable outcomes between synthetic mesh repairs and allograft repairs in postoperative complications, need for revision reconstruction, and functional outcomes as measured by the knee society score [ 15 ].…”

“…In recent years, there has also been an increased usage of synthetic meshes over traditional allografts due to cheaper costs, easier availability, and decreased risks of host immune reactions or disease transmission [16]. Meta-analysis such as that by Deren et al shows comparable outcomes between synthetic mesh repairs and allograft repairs in postoperative complications, need for revision reconstruction, and functional outcomes as measured by the knee society score [15].…”

Extensor mechanism failure in total knee arthroplasty

“…However, both reconstruction techniques carry a high risk of complications, including infection and failure with persistent extensor lag. 39 , 40 …”

Bilateral Extensor Mechanism Allograft Reconstruction in Native Knees

“…Various reconstructive techniques using synthetic mesh or tendon auto/allograft have been described 18,19 . Complete extensor mechanism allograft reconstruction has been used for complicated scenarios including oncologic treatment 20 and failed knee arthroplasty [21][22][23] with satisfactory results.…”