Diagnostic Values of 3 Methods for Evaluating Meniscal Healing Status After Meniscal Repair

BACKGROUND: The main diagnostic methods for evaluating repaired menisci include second-look arthroscopy, clinical assessment, and magnetic resonance imaging (MRI). None of the previous studies applied all 3 methods for each consecutive case nor made any systematic comparison among them. PURPOSE: This study was undertaken to compare the diagnostic values of the 3 different methods in an attempt to propose suggestions for evaluating meniscal healing results. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Eighty-one patients (89 menisci), with a mean age of 25.4 years (standard deviation [SD], 7.7; range, 15-50 years), underwent arthroscopic meniscal repair, including 65 medial menisci and 24 lateral menisci. Follow-up evaluation for each meniscus included clinical assessment, second-look arthroscopy, and postoperative MRI, with a mean follow-up time of 25.4 months (SD, 6.0; range, 17.4-48.3 months). Defined criteria for unhealed meniscus were any symptoms such as joint-line tenderness, swelling, locking, or positive McMurray test for clinical assessment; cleft or instability on second-look arthroscopy; and grade 3 signal intensity shown at the repaired site on postoperative MRI. RESULTS: Seventy-seven menisci were confirmed completely healed by second-look arthroscopy, with a total healing rate of 86.5%. Clinical assessment found 63 menisci healed, with a clinical healing rate of 70.8% (sensitivity, 58.3%; specificity, 75.3%; accuracy, 73.0%). By using the second-look arthroscopy as the standard, the sensitivity, specificity, and accuracy, respectively, were calculated for MRI in 5 sequences: sagittal T1: 91.7%, 58.4%, 62.9%; sagittal proton density (PD): 83.3%, 40.3%, 46.1%; sagittal T2: 58.3%, 89.6%, 85.4%; coronal PD: 75.0%, 74.0%, 74.2%; and coronal T2: 41.7%, 98.7%, 91.0%. CONCLUSION: Second-look arthroscopy was the most dependable way to determine meniscal healing. Clinical assessment had obvious limitations in diagnosing healed menisci. On MRI examination, T2-weighted sequences had obviously higher specificity and accuracy, while PD and T1 had higher sensitivity. The diagnostic value could be improved by a combined application of different sequences.