Summary
The residual meniscus width with the midbody would be recommended to be around 11 mm during surgery.
Abstract
Introduction
Objectives: Arthroscopic reshaping surgery is the first treatment option for a symptomatic discoid lateral meniscus (DLM) to preserve the peripheral rim. However, adequate residual volume of meniscus during surgery is unclear. The purpose of this study was to measure the meniscus just after reshaping surgery, 3 months and 2 years after the surgery for a DLM and divided into three groups; higher, middle and low volume, to verify when the morphological change occurred.
Methods
We retrospectively reviewed DLM patients who underwent surgery minimum 2 years follow-up. Magnetic resonance imaging (MRI) was performed just after surgery, 3 and 24 months postoperatively. The residual meniscal width of anterior horn, midbody and posterior horn were measured every period. We divided into three groups according to the volume of the midbody based on coronal MRI just after surgery: high volume group (more than 13mm) (H group), middle volume group (9mm or more and less than 13mm) (M group) and low volume group (less than 9mm) (L group). Statistical differences between groups were calculated using a one-way analysis of variance with a post hoc Student’s t-test. p < 0.05 was considered significant.
Results
We included 55 knees of 55 patients in this study. The mean age at the time of surgery was 16.7 years. Overall, the width of the midbody decreased significantly from 0 to 24 months after surgery from 10.6 to 6.4 mm (P<0.001). The width of the midbody in H and M group was wider than that in M (P<0.001) and L (P<0.001) group at 0 months, respectively. Although the width of the midbody in H group was no difference between M group at postop 3 (P=0.11) and 24 (P=1.00) months, H and M groups was wider than L groups at postop 3(P<0.001, <0.001) and 24 (P=0.009, 0.015) months, respectively.
Conclusions
More than 13mm residual meniscus (H group) rapidly decreases the width to the same level of M group and there was no difference between H and M group at 24 months after the surgery. The residual meniscus width with the midbody would be recommended to be around 11 mm during surgery.