OBJECTIVE: To evaluate the MR imaging findings of painful type II accessory navicular bone and to correlate these with the surgical and pathologic findings. MATERIALS AND METHODS: The MR images of 17 patients with medial foot pain and surgically proven type II accessory navicular abnormalities were reviewed. The changes of signal intensity in the accessory navicular, synchondrosis and adjacent soft tissue, the presence of synchondrosis widening, and posterior tibial tendon (PTT) pathology on the T1-weighted and fat-suppressed T2-weighted images were analyzed. The MR imaging findings were compared with the surgical and pathologic findings. RESULTS: The fat-suppressed T2-weighted images showed high signal intensity in the accessory navicular bones and synchondroses in all patients, and in the soft tissue in 11 (64.7%) of the 17 patients, as well as synchondrosis widening in 3 (17.6%) of the 17 patients. The MR images showed tendon pathology in 12 (75%) of the 16 patients with PTT dysfunction at surgery. The pathologic findings of 16 surgical specimens included areas of osteonecrosis with granulomatous inflammation, fibrosis and destruction of the cartilage cap. CONCLUSION: The MR imaging findings of painful type II accessory navicular bone are a persistent edema pattern in the accessory navicular bone and within the synchondrosis, indicating osteonecrosis, inflammation and destruction of the cartilage cap. Posterior tibial tendon dysfunction was clinically evident in most patients.
Adolescent ; Adult ; Female ; Humans ; Korea ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Orthopedic Procedures ; Osteonecrosis/diagnosis/surgery ; Pain/pathology ; Posterior Tibial Tendon Dysfunction/diagnosis/surgery ; Tarsal Bones/*pathology/radiography/*surgery ; Tendinopathy/diagnosis/surgery ; Treatment Outcome

BACKGROUND: Patients with chronic lateral ankle instability also have peroneal tendinopathy often. However, preoperative MRIs of these patients are vague in many cases. Our study was performed to see the reliability of MRI findings of peroneal tendinopathy in patients with chronic lateral ankle instability. METHODS: MRI images for 82 patients who had chronic lateral ankle instability, and had received surgical treatment between March 2006 and November 2009 were compared with impressions from operating rooms. The mean age of patients was 36.4 years (range, 15 to 64 years), 82 ankles were studied, and patients with rheumatoid diseases were excluded from the study. RESULTS: Of the 82 cases, 26 were true positives, 38 true negatives, 13 false positives and 5 false negatives. Of 39 cases of peroneal tendinopathy diagnosed from MRI, 14 had peroneal tendon partial tears, 15 tenosynovitis, 3 dislocations, 17 low-lying muscle bellies, and 6 peroneus quartus muscles. Of 31 cases of peroneal tendinopathy observed in surgery 11 had peroneal tendon partial tears, 4 tenosynovitis, 5 dislocations, 12 low-lying muscle belliess, and 1 peroneus quartus muscle. Sensitivity and specificity of peroneal tendinopathy were 83.9% and 74.5%, respectively. Positive predictive value was 66.7%. Negative predictive value was 88.4%. Accuracy rate was 78.0%. CONCLUSIONS: MRI is a useful diagnostic tool for detecting peroneal tendinopathy in patients with chronic lateral ankle instability. However, MRI is vague in many cases. Therefore, a thorough delicate physical examination and careful observation is needed.
Adolescent ; Adult ; *Ankle Joint/surgery ; Chronic Disease ; Female ; Humans ; Joint Instability/*complications/surgery ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Observer Variation ; Predictive Value of Tests ; Sensitivity and Specificity ; Tendinopathy/*diagnosis/etiology/surgery ; Tendon Injuries/complications/diagnosis ; Young Adult