Summary

This study compares the diagnostic value of clinical assessment and magnetic resonance imaging in order to identify lack of meniscal healing after meniscal repair using rearthroscopy as gold standard. Sensitivity, specificity, positive and negative predictive values are calculated on different MRI sequences and different clinical symptoms.

Abstract

Background

Lack of healing after meniscus repair is seen in 25-30 % of patients. The role of magnetic resonance imaging (MRI) as a diagnostic tool in patients with clinical symptoms after meniscal repair, is not well described.

Purpose

/ Aim of Study: To compare the diagnostic value of MRI with second-look arthroscopy after meniscus repair in patients with clinical symptoms of an unhealed meniscus.

Materials And Methods

Eighty-two patients (34 women, 48 men, 83 menisci) with a mean age of 24.4 years were included. All patients had primary meniscus repair. MRI and second-look- arthroscopy were performed due to clinical symptoms of an unhealed meniscus. The symptoms recorded were swelling, joint-line tenderness, locking and a positive McMurray test. The MRIs were analysed for meniscal healing by a radiologist blinded for clinical data. Second-look arthroscopy recordings were equally examined and used as gold standard. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for both clinical symptoms and meniscal healing based on MRI findings.

Findings

Results

MRI analysis found 22 (26.5 %) healed menisci and 61 (73.5%) unhealed, whereas second-look arthroscopy found 15 (18.1%) healed menisci and 68 (81.9%) unhealed menisci. Sensitivity, specificity, PPV and NPV respectively were calculated for MRI overall: 0.85, 0.80, 0.95, 0.55 and the five most frequently used MRI sequences: sagittal STIR: 0.69, 0.75, 0.95, 0.30; sagittal pd: 0.29, 0.83, 0.89, 0.20; sagittal T2*: 0.33, 1.00, 1.00, 0.26; coronal T1: 0.26, 1.00, 1.00, 0.25; axial STIR: 0.15, 0.88, 0.88, 0.15.
Sensitivity, specificity, PPV and NPV for the symptoms were; swelling: 0.38, 0.73, 0.86, 0.21; joint-line tenderness: 0.75, 0.53, 0.88, 0.33; locking: 0.29, 0.73, 0.83, 0.19, and McMurrays test: 0.12, 1.00, 1.00, 0.21.

Conclusions

MRI provides an acceptable sensitivity and PPV in diagnosing an unhealed meniscus after repair. Sagittal STIR has the highest sensitivity and NPV, whereas sagittal T2* and coronal T1 have the highest PPV.
Regarding symptoms, joint-line tenderness has the highest sensitivity opposed to swelling and locking. All four symptoms show a rather high PPV.