PURPOSE: To determine the accuracy of MR imaging in predicting bone graft healing in patients with scaphoid non-union. MATERIAL AND METHODS: 21 patients with scaphoid non-union were examined with MR imaging prior to bone grafting (conventional bone graft in 14 cases and vascularized bone graft in 7 cases). The protocol included unenhanced and Gadolinium-enhanced sequences. Signal intensity and homogeneity of the proximal fragment was analysed by two independent radiologists. MRI findings were then correlated to the postoperative rate of union. RESULTS: Healing occurred in 17 cases and failed in 4 cases with a mean follow up of 14 months. Intraobserver agreement in MR reading was respectively 0.92 et 0.86. Interobserver agreement was 0.88. On Tl-wi, the proximal fragment was hyperintense in 1 case (with positive surgical result), heterogeneous low signal intensity in 7 cases (healing in n = 7) and homogeneous low signal intensity in 13 cases (healing in n = 9). On T2-wi, the proximal fragment was hypointense in 4 cases (healing in n = 3), homogeneous high signal in 5 cases (healing in n = 4) and heterogeneous high signal intensity in 12 cases (healing in n = 10). After Gadolinium injection, enhancement was homogeneous in 4 cases (healing in n = 4), heterogeneous in 8 cases (healing in n = 7) and absent in 9 cases (healing in n = 6). In the group with no enhancement, 5 patients were treated with vascularized bone graft (healing in n = 4) and 4 with conventional bone graft (healing in n = 2). CONCLUSION: The absence of enhancement of the proximal scaphoid fragment leads to poor surgical results except for vascularized bone graft.
PURPOSE: To determine the accuracy of MR imaging in predicting bone graft healing in patients with scaphoid non-union. MATERIAL AND METHODS: 21 patients with scaphoid non-union were examined with MR imaging prior to bone grafting (conventional bone graft in 14 cases and vascularized bone graft in 7 cases). The protocol included unenhanced and Gadolinium-enhanced sequences. Signal intensity and homogeneity of the proximal fragment was analysed by two independent radiologists. MRI findings were then correlated to the postoperative rate of union. RESULTS: Healing occurred in 17 cases and failed in 4 cases with a mean follow up of 14 months. Intraobserver agreement in MR reading was respectively 0.92 et 0.86. Interobserver agreement was 0.88. On Tl-wi, the proximal fragment was hyperintense in 1 case (with positive surgical result), heterogeneous low signal intensity in 7 cases (healing in n = 7) and homogeneous low signal intensity in 13 cases (healing in n = 9). On T2-wi, the proximal fragment was hypointense in 4 cases (healing in n = 3), homogeneous high signal in 5 cases (healing in n = 4) and heterogeneous high signal intensity in 12 cases (healing in n = 10). After Gadolinium injection, enhancement was homogeneous in 4 cases (healing in n = 4), heterogeneous in 8 cases (healing in n = 7) and absent in 9 cases (healing in n = 6). In the group with no enhancement, 5 patients were treated with vascularized bone graft (healing in n = 4) and 4 with conventional bone graft (healing in n = 2). CONCLUSION: The absence of enhancement of the proximal scaphoid fragment leads to poor surgical results except for vascularized bone graft.