2023 ISAKOS Biennial Congress ePoster
Bidirectional Evaluation for the Lateral Meniscal Extrusion After Repairing Isolated Longitudinal Tear
Akira Tsujii, MD, PhD, Suita, Osaka JAPAN
Seira Sato, MD, PhD, Suita, Osaka JAPAN
Tomoki Ohori, MD, PhD, Suita, Osaka, Asia JAPAN
Tatsuo Mae, MD, PhD, Suita, Osaka JAPAN
Kazutaka Kinugasa, MD, PhD, Sakai, Osaka JAPAN
Yasukazu Yonetani, MD, PhD, Hirakata, Osaka JAPAN
Masayuki Hamada, MD, Sakai, Osaka JAPAN
Ken Nakata, MD, PhD, Suita, Osaka JAPAN
Osaka University, Suita, Osaka, JAPAN
FDA Status Not Applicable
Summary
Not only lateral extrusion but also posterior extrusion should be evaluated on MRI to assess meniscal function because the posterior extrusion changes largely after the operation over time.
ePosters will be available shortly before Congress
Abstract
Purpose
The incidence of meniscal repairs increases over the past few decades due to understanding of its crucial, chondroprotective, role in knee joints and due to advancements in surgical instruments. Meniscal extrusion has become widely recognized as one of the measurement methods for meniscal function because extruded meniscus is associated with meniscal tear, cartilage damage, and tibiofemoral osteoarthritis. We have already reported that postoperative lateral meniscus extruded posteriorly over time in the repaired meniscus with concomitant anterior cruciate ligament reconstruction (ACLR), but meniscal position might be changed because ACLR changes tibiofemoral relationship. It is unknown how meniscal extrusion changes in the isolated meniscus tear. Thus, the purpose of this study is to evaluate meniscal extrusion on magnetic resonance images (MRI) after repairing isolated lateral meniscus (LM) tear.
Methods
From 2014 to February 2022, 215 patients underwent isolated meniscal repair. Among them, patients who underwent inside-out repair for isolated LM longitudinal tears were retrospectively reviewed. After surgery, operated knee was immobilized with a brace for 2 weeks, then range of motion exercise and partial weight bearing were started, and full weight bearing was allowed at 4 weeks. Jogging was allowed at 3 months, and a return to sports activities was permitted after 6 months. Patients who underwent MRI at 3 time points (preoperatively, immediately after the operation, and 6 months postoperatively) were included, and patients who had locked lateral meniscus were excluded because preoperative MRI measurements were not available. Finally, 10 patients were included in this study. Meniscal extrusion was assessed in coronal and sagittal plane, and the changes from pre- to post-operative values were analyzed with the preoperative value as the baseline. Lateral extrusion was measured by the distance from the peripheral margin of the lateral tibial plateau to the meniscocapsular junction of the LM in coronal plane. Posterior extrusion was measured by the distance from the inner margin of the anterior horn of the LM to the meniscocapsular junction of the posterior horn of the LM in sagittal plane.
Results
There were 9 female and 2 male patients with a mean age of 26.2. All patients had no pain and swelling with no difficulty in daily activities at final follow-up. Mean changes of the lateral/posterior extrusion were -0.2 ± 0.8 / 0.8 ± 1.6 mm at immediately after the operation and -0.4 ± 0.7 / 1.7 ± 1.6 mm at 6 months postoperatively.
Conclusions
It was shown that posterior extrusion increased immediately after inside-out repair and it progressed at 6 months postoperatively, while lateral extrusion had not changed. This might be due to that the tear sites were posterior segment and the sutures were tightened against posterior joint capsule. As in the case of LM repair with concomitant ACLR, meniscal extrusion towards posterior direction progressed over time. Meniscal extrusion should be evaluated not only on coronal plane but also on sagittal plane.