The reduction of bowing of the fifth metatarsal after intramedullary screw insertion for jones fractures may reduce risk of refracture.

BACKGROUND

Bone morphological change intramedullary screw fixation, characterized by gap widening at the plantar side of the fifth metatarsal shaft, is considered a factor contributing to delayed union and pseudoarthrosis. However, the reduction in bowing of the fifth metatarsal, which occurs alongside the plantar gap, has not been reported. A reduction in bowing height, concurrent with plantar gap widening, may protect against refracture.

PURPOSE: This study aimed to investigate the effects of surgery for Jones fractures on morphological changes associated with refractures.

METHODS

From 2008 to 2019, 222 patients underwent headless intramedullary screw fixation for Jones fractures. Of these, 19 feet had postoperative refractures, which were matched to 57 feet with normal bony union (1:3 ratio) based on bone graft, screw diameter, and metatarsal screw ratio.

RESULTS

X-ray analysis compared the height of bowing of the fifth metatarsal between group R (refracture patients) and group U (normal union patients).In Group R, the bowing height remained at 4.5 mm before and after surgery. In Group U, the bowing height decreased from 4.5 mm preoperatively to 4.3 mm postoperatively (P < 0.01).

CONCLUSION

The reduction in bowing height of the fifth metatarsal was significantly greater in the normal union group than in the refracture group after intramedullary screw fixation. This suggests that the alignment change post-surgery may help prevent refracture.