Biomechanical analysis of a centralization procedure for extruded lateral meniscus after meniscectomy in porcine knee joints

Abstract

The recently developed arthroscopic centralization for lateral meniscal extrusion has obtained satisfactory short‐term clinical and radiological results and improves the meniscus biomechanical properties. However, the effectiveness of treatment for meniscus extrusion after partial meniscectomy still requires elucidation. This study investigated the effect of centralization with modifications from a mechanical viewpoint. Porcine knee joints (N = 6) were set in a universal tester under the following conditions: (1) Intact; (2) Meniscectomy: Inner half of the posterior half meniscus was removed; (3) Extrusion: Posterior meniscus was dislocated laterally by transecting the posterior root and the meniscotibial ligament; (4) Centralization‐1: Centralization procedure using one anchor; (5) Centralization‐2: Centralization procedure using two anchors; and (6) Centralization‐ad: Centralization with capsular advancement using two anchors. Load distributions and contact pressure in the meniscus and tibial cartilage were evaluated with an axial compressive force of 200 N. After meniscectomy, the tibial cartilage load increased and that of the medial margin of the posterior part of the meniscus decreased. When the meniscus was extruded, the load was concentrated only on the tibial cartilage. Centralization‐1 increased the load on the meniscus, while Centralization‐2 further increased the meniscus load but decreased the tibial cartilage load. Centralization‐ad further decreased the load on the tibial plateau. The average contact pressure of the tibial cartilage was significantly higher in the Extrusion group than in the Intact group or the Centralization‐ad group. From a biomechanical viewpoint, centralization with capsular advancement was the most effective of the tested procedures for treatment for an extruded meniscus after partial meniscectomy.

Acute repair of meniscus root tear partially restores joint displacements as measured with MRI and loading in a porcine knee

“…Studies using pressure sensors placed into the joint space showed that the femoral contact point shifts medially after meniscus injury [2]- [4], [16], similar to our meniscus and femur results.…”

“…Our findings for the femur displacements agree with previous studies of joint kinematics. Studies using pressure sensors placed into the joint space showed that the femoral contact point shifts medially after meniscus injury [2]–[4], [16], similar to our meniscus and femur results. Contact pressure tracking primarily finds that the contact area decreases, indicating that the meniscus is not carrying load due to extrusion by the femur.…”

“…Thus, further in vivo studies are needed to explore if the suture anchor repair aids in healing to increase the strength of the anchor/anterior attachment complex and to reduce medial extrusion of the meniscus under load. Another solution to reduce medial extrusion may be to add sutures on the outside of the joint for meniscus centralization, especially in the anterior half, similar to studies by the Sekiya group [15], [16]. The methods used in the present study are valuable to test other repair strategies to restore joint kinematics and meniscus load distribution to protect the underlying cartilage.…”

“…First, though we kept the joint capsule and surrounding ligaments as intact as possible, a small incision was required for creation of the tear and for the repair procedure. This was an approximately 3.0 cm vertical incision in the joint capsule to the medial side of the patellar tendon, which is considerably smaller than the incisions or dissections used in other studies using pressure sensors [2]–[4], [16], [17]. Secondly, due to the aligned nature of the meniscus attachment, there is the possibility of suture slippage or pull-out in the Repair group.…”

“…Previous work has shown that there is a relation between greater meniscal extrusion and joint degeneration [13]- [15]. Some studies have shown, using pressure sensors (e.g., Tek-Scan) inserted into the joint space, that meniscus injury leads to larger peak forces and smaller contact areas on the tibial plateau; however, these studies required transecting the joint capsule and sometimes the LCL or MCL to make the measurement [2]- [4], [16], [17]. Therefore, developing non-invasive measurement of joint and meniscus kinematics is critical to understanding the impact of meniscus injury and repair on joint loading and chondroprotection.…”