# Tibial spino–meniscal clearance: A reproducible MRI‐derived measurement associated with hypermobile lateral meniscus

## TL;DR

This study introduces a new MRI measurement called tibial spino-meniscal clearance (TSMC) that is associated with a specific type of meniscal instability in the knee and is reproducible across observers.

## Contribution

The novel contribution is the development and validation of TSMC as a reproducible MRI-based indicator of hypermobile lateral meniscus.

## Key findings

- TSMC values were significantly lower in patients with confirmed hypermobile lateral meniscus compared to controls.
- The TSMC measurement showed excellent intra- and interobserver reliability.
- TSMC remained independently associated with hypermobility after adjusting for demographic and anatomical variables.

## Abstract

To evaluate whether tibial spino–meniscal clearance (TSMC), a magnetic resonance imaging (MRI)‐derived imaging measurement, is associated with arthroscopically confirmed hypermobile lateral meniscus (HML), and to assess the reproducibility of this measurement.

A combined retrospective–prospective diagnostic accuracy study was conducted including 164 patients who underwent knee MRI followed by arthroscopy within six months. TSMC was measured on sagittal MRI as the shortest distance between the apex of the lateral tibial spine and the inner margin of the posterior horn of the lateral meniscus. Three blinded observers independently performed measurements to assess intra‐ and interobserver reliability using intraclass correlation coefficients (ICCs). Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis, and multivariable logistic regression was used to examine the association between TSMC and HML.

Mean TSMC values were lower in patients with arthroscopically confirmed HML compared with controls. The measurement demonstrated excellent intra‐ and interobserver reliability. ROC analysis showed good discriminatory performance for identifying HML, and TSMC remained independently associated with hypermobility after adjustment for demographic and anatomical variables.

TSMC is a reproducible MRI‐derived imaging measurement associated with HML. While these findings suggest that TSMC may assist in preoperative suspicion of lateral meniscal instability, further external validation is required before routine clinical application.

Level III.