Radiographic Analysis of National Football League Players' Fifth Metatarsal Morphology Relationship to Proximal Fifth Metatarsal Fracture Risk

Background:: Fractures of the proximal fifth metatarsal are one of the most common foot injuries in athletes. Repetitive stresses endured by the fifth metatarsal can lead to stress fracture, delayed union, and refracture, making optimal treatment challenging. A radiographic analysis of fifth metatarsal morphology and foot type in National Football League (NFL) players was performed to investigate morphologic risk factors for these injuries.

Methods:: This was a case-control study that looked at NFL players treated between 1992 and 2012, as well as participants at the NFL Combine. Ninety-six feet (51 athletes) were included. Fractures were present in 15 feet. Two reviewers assessed fifth metatarsal morphology and foot type on anteroposterior, lateral, and oblique radiographs. Differences in foot type and metatarsal morphology between athletes with and without fractures were determined.

Results:: On anteroposterior radiographs, significant differences in apex medullary canal width, 4-5 intermetatarsal angle, fifth metatarsal angle, and talar head uncovering were observed between fractured and non-fractured feet ( P = .001, .003, .004, .008, respectively). On lateral radiographs, significant differences in the fifth metatarsal length, distance to apex, apex height, fifth metatarsal angle, and talocalcaneal angle were observed between fractured and nonfractured feet ( P = .04, .01, .02, .01, .01, respectively). On oblique radiographs, a significant difference was observed in apex height between fractured and nonfractured feet ( P = .002).

Conclusion:: Individuals with long, narrow, and straight fifth metatarsals with an adducted forefoot were most at risk for fifth metatarsal fractures. With this insight, attempts at fracture prevention can be implemented via footwear modifications, orthoses, and off-loading braces that account for those aforementioned morphologic attributes that place athletes at risk.

Level of evidence:: Level III, retrospective comparative study.