Sarah I Kamel1, Jeffrey A Belair2, Tarek M Hegazi3, Ethan J Halpern1, Vishal Desai1, William B Morrison1, Adam C Zoga1. 1. Department of Musculoskeletal Radiology, Thomas Jefferson University Hospital, Main Building 1090, Philadelphia, PA, 19107, USA. 2. Department of Musculoskeletal Radiology, Thomas Jefferson University Hospital, Main Building 1090, Philadelphia, PA, 19107, USA. Jeffrey.belair@jefferson.edu. 3. Department of Radiology, Imam Abdulrahman Bin Faisal University, College of Medicine, Dammam, Saudi Arabia.
Abstract
OBJECTIVE: To provide a novel MRI classification system for the symptomatic type II os naviculare by creating a standardized grading of associated bone marrow edema (BME) and correlating with patient symptoms. METHODS: BME was classified on an ordinal scale: grade 1, faint signal immediately adjacent to the synchondrosis; grade 2, intermediate signal within the os and navicular tuberosity without extending to the navicular body; grade 3, intense signal extending to the navicular body. BME on 59 MRIs was independently graded by three radiologists. Inter- and intra-observer agreement was analyzed using intraclass correlation coefficient. Univariate and multivariate analyses assessed for patient and imaging characteristics predictive of subjective pain score. A cohort of 82 patients without BME represented a control group. RESULTS: Inter-observer agreement of BME grade was 0.95 (CI 0.93-0.97) and intra-observer was 0.92 (CI 0.87-0.96), indicating excellent agreement. In patients with BME, predictors of more severe pain were longer duration of pain (p = 0.02) and presence of soft tissue edema overlying the os naviculare (p < 0.001). One hundred percent of subjects with BME localized their pain to the medial midfoot (59/59) versus 25.6% (21/82) of controls (p < 0.001). CONCLUSIONS: This novel grading system provides reliable quantification of BME associated with os naviculare, which is a specific cause of medial foot/ankle pain. Early diagnosis is important as pain severity worsens with longer duration of symptoms. Pain severity is correlated with soft tissue edema overlying the os, which may be secondary to extrinsic compression, reactive to biomechanical stress, or reflect direct trauma.
OBJECTIVE: To provide a novel MRI classification system for the symptomatic type II os naviculare by creating a standardized grading of associated bone marrow edema (BME) and correlating with patient symptoms. METHODS: BME was classified on an ordinal scale: grade 1, faint signal immediately adjacent to the synchondrosis; grade 2, intermediate signal within the os and navicular tuberosity without extending to the navicular body; grade 3, intense signal extending to the navicular body. BME on 59 MRIs was independently graded by three radiologists. Inter- and intra-observer agreement was analyzed using intraclass correlation coefficient. Univariate and multivariate analyses assessed for patient and imaging characteristics predictive of subjective pain score. A cohort of 82 patients without BME represented a control group. RESULTS: Inter-observer agreement of BME grade was 0.95 (CI 0.93-0.97) and intra-observer was 0.92 (CI 0.87-0.96), indicating excellent agreement. In patients with BME, predictors of more severe pain were longer duration of pain (p = 0.02) and presence of soft tissue edema overlying the os naviculare (p < 0.001). One hundred percent of subjects with BME localized their pain to the medial midfoot (59/59) versus 25.6% (21/82) of controls (p < 0.001). CONCLUSIONS: This novel grading system provides reliable quantification of BME associated with os naviculare, which is a specific cause of medial foot/ankle pain. Early diagnosis is important as pain severity worsens with longer duration of symptoms. Pain severity is correlated with soft tissue edema overlying the os, which may be secondary to extrinsic compression, reactive to biomechanical stress, or reflect direct trauma.
Entities:
Keywords:
Accessory navicular syndrome; Bone marrow edema; Medial foot pain; Painful type II os naviculare; Posterior tibial tendinosis; Synchondrosis