Does surgical technique influence graft extrusion following meniscal allograft transplantation – a systematic review

Purpose To provide an update on the incidence and extent of graft extrusion following meniscus allograft transplantation (MAT) and to systematically review the literature to identify if the type of root fixation or additional surgical techniques may reduce the risk of developing graft extrusion. Methods A systematic search, in accordance with the PRISMA guidelines, was conducted using the MEDLINE, EMBASE, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Patients undergoing medial meniscal allograft transplantation (MMAT) or Lateral MAT (LMAT) were included. The primary outcome measure was meniscal extrusion measured on post-operative MRI taken > 6 weeks after the MAT. The following extrusion outcomes were investigated; Absolute extrusion (AE), Relative percentage extrusion (RPE), Proportion of major extrusion (PME). Additional surgical techniques that reduced the risk of developing graft extrusion in the included comparative studies were identified. Results For MMAT, the pooled mean extrusion outcomes were; AE 3.2 mm vs 3.36 mm and RPE 44.43% vs 33.18% for soft tissue versus (vs) bony fixation, respectively. The pooled mean PME for soft tissue fixation MMAT was 51.62%. For LMAT, the pooled mean extrusion outcomes were; AE: 3.72 mm vs 2.78 mm , RPE: 31.89% vs 29.47% and PME: 64.37% vs 35.80% for soft tissue vs bony fixation, respectively. Additional capsulodesis was identified as a technique to reduce LMAT extrusion. Conclusion This study highlights that graft extrusion is a common finding following MMAT and LMAT, independent of the root fixation technique. However, MAT extrusion with bony fixation was, depending on the outcome measurement, lower or equal to soft tissue fixation.