Intercondylar Notch Size Can Be Predicted on Preoperative Magnetic Resonance Imaging

PURPOSE: To develop a standardized method of intercondylar notch measurement on preoperative radiographs and magnetic resonance imaging (MRI) and validate that it could predict intraoperative notch measurements. METHODS: The charts and imaging of 50 patients undergoing anterior cruciate ligament reconstruction were reviewed. A standardized method of intercondylar notch measurement on radiographs and MRI was used by 3 blinded reviewers. Arthroscopic measurements were made by the surgeon who was blinded to the imaging measurements. Interrater reliability was determined between reviewers and between imaging and arthroscopic measurements using interclass correlation coefficients (r). RESULTS: The average notch base width was 16.5 (± 2.7) mm on MRI, 19.0 (± 3.4) mm on radiographs, and 15.8 (± 3.0) mm on arthroscopic measurement. The radiographic notch base width measurements were on average 1.2 times greater than the arthroscopic measurements. There was no significant difference between males and females in notch base width (16.7 mm vs 15.3 mm, P = .19) or area (312.5 mm(2) vs 284.3 mm(2), P = .17). Interrater reliability was excellent between the reviewers for notch base width measurement on both MRI (r = 0.91) and radiographs (r = 0.95). Good-to-excellent interrater reliability between notch base width measurements on MRI and arthroscopy (r = 0.78, 0.73, 0.7) and fair-to-good interrater reliability between notch base width measurements on radiographs and arthroscopy were found (r = 0.61, 0.58, 0.55). CONCLUSIONS: This study introduces a reliable method of using preoperative MRI to predict intercondylar notch width during arthroscopy. This data can be used to identify patients with narrow notches preoperatively. LEVEL OF EVIDENCE: Level III, diagnostic study.