Peripheral fixation of meniscal allograft does not reduce coronal extrusion under physiological load

Abstract

Purpose Meniscal graft extrusion is a concern following meniscal allograft transplantation (MAT). MAT surgical techniques continue to evolve in an effort to reduce extrusion; however, improvements remain difficult to measure in vivo. A novel MRIcompatible in vitro loading device capable of applying physiologically relevant loads has been developed, allowing for the measurement of extrusion under a variety of controllable conditions. The objective of this study was to compare maximal medial MAT extrusion (1) with and (2) without an additional peripheral third point of fixation on the tibial plateau. Methods Twelve human cadaveric knees underwent medial MAT, utilizing soft tissue anterior and posterior root fixation via transosseous suture, with a third transosseous suture tied over a button providing peripheral fixation on the tibial plateau. The joint was positioned at 5 degrees of flexion and loaded to 1 × body weight (647.7 ± 159.0 N) during MR image acquisition, with and without peripheral fixation. The joint was then positioned at 30 degrees of flexion and the process was repeated. Maximal coronal extrusion was measured. Results An increase in maximal coronal meniscal extrusion was noted between the unloaded and loaded states. At 30 degrees of flexion, with the addition of a peripheral fixation point, a statistically significant difference in absolute extrusion (p = 0.02) and relative percent extrusion (p = 0.04) between the unloaded and loaded state was found. The addition of a peripheral fixation suture resulted in an overall mean percent difference of − 2.49% (SD 14.1; 95% CI − 11.95, 6.97; n.s.) in extrusion at 5 degrees of flexion and a mean percent difference of − 0.95% (SD 7.3; 3.71; n.s.) in extrusion at 30 degrees of flexion. These differences were not statistically significant. Conclusion These results suggest that the addition of a peripheral anchor in medial MAT does not reduce the amount of maximal coronal extrusion and, therefore, may not confer any clinical benefit. Surgical techniques utilized to reduce MAT extrusion need further investigation to understand if the added technical difficulty and potential expense is warranted.

In Vivo Kinematic Analysis of Lateral Meniscal Allograft Transplantation With Soft Tissue Fixation

“…16 Some authors have conducted imaging studies that correlate the grade of meniscal extrusion with the surgical technique, obtaining controversial results. 6,11,21,22 Koh et al 13 demonstrated instead that lateral MAT was significantly more extruded than medial MAT at 3 years’ follow-up; this difference might be related to differences in the anatomic restraints of the medial and lateral compartments.…”

Effect of Injury to the Lateral Meniscotibial Ligament and Meniscofibular Ligament on Meniscal Extrusion: Biomechanical Evaluation of the Capsulodesis and Centralization Techniques in a Porcine Knee Model

“…Starting from a base load of 1 N, a repetitive load with a magnitude of 10 N was then applied 100 times (frequency, 1 Hz). A ground-reaction force of 200 N was applied to the distal tibia, 5,8 and scaled loads of 50 N and 20 N were applied to the quadriceps and hamstrings, respectively, at 30° and 60° of flexion (each angle of flexion was confirmed using a goniometer and defined as the angle formed between the anatomic axes of the femur and the tibia at their lateral aspects). The porcine knee cannot extend to 0°, beginning its range of motion at 30° of flexion.…”

Meniscus Allografts: How to Improve Clinical Results, Limit Chondral Degeneration?

“…So one of the goals of the technical improvements in MAT should be to decrease graft extrusion. Mid-body fixation of MAT to the tibia doesn't prevent extrusion under loading conditions [12]. Soft tissue fixation leads to a higher level of meniscal extrusion when compared to bone block fixation technique [3].…”