gms | German Medical Science

Objectives/Interrogation: Preoperative image assessment for osteonecrosis in the proximal spicula is important for selecting the surgical technique to apply to scaphoid fracture pseudarthrosis. However, synostosis may also be obtained by nonvascularized bone graft, and actual divergence from image findings has been noted. Here, we report pseudarthrosis preoperative image findings and intraoperative pathological findings in comparison with the therapeutic outcomes of vascularized bone graft.

Methods: Taken from among vascular bone graft operations for 116 hands in treatment of vascular scaphoid fracture, the subjects in this study were 22 hands presenting pathological specimens of pseudarthrosis regions. The mean age of the subjects was 28.8 years, the male:female ratio was 20:2, the mean time from injury to surgery was 52.6 months, and the position of the pseudarthrosis was proximal:medial:distal in 8:13:1 hands. Surgery was performed by the Zaidemberg technique for 21 hands and the Makino technique for 1 hand. X-ray images assessed using the Ikeda classification showed filamentary in 2 cases, cystic in 7 cases, and sclerotic or transpositional in 13 cases. The preoperative MR images (obtained for 20 cases) for proximal spicule, T1, and T2 findings were compared with the peripheral carpal bones and assessed for signal intensity. Low signal intensity was found in both T1 and T2 in 8 cases and low T1 signal intensity alone in 7 cases. In the pathologic diagnosis, samples from within the proximal spicule of the pseudarthrosis were taken and assessed for osteonecrosis. The image findings, pathological diagnoses, and postoperative outcomes were investigated.

Results and Conclusions: In the pathological investigation, osteonecrosis was found in 11 cases (50.0%), with the position proximal in 6 cases (necrosis 75.0%), medial in 5 cases (38.5%), and distal in 0 cases (0%), and thus most often proximal. In the Ikeda classification, osteonecrosis was filamentous in 2 cases (100%), cystic in 4 cases (57.1%), and sclerosal or transpositional in 5 cases (6.7%). From MRI, osteonecrosis was both T1 and T2 in 4 cases (50.0%) and T1 alone in 5 cases (71.4%). The synostosis rate was 11 cases (100%) in the necrotic group and 10 cases (90.9%) in the non-necrotic group. Osteonecrosis findings by pathological examination did not necessarily match the X-ray or MRI findings, thus indicating that determination of osteonecrosis as a preoperative finding is difficult.