Functional outcome of 103 fractures of the proximal fifth metatarsal bone.

Background: Metatarsal fractures are common skeletal injuries of the lower extremity in adults. The majority involves the proximal fifth metatarsal bone. In the current literature, there still exists controversy regarding treatment recommendations for the different fracture entities.

Methods: All patients suffering from single fractures to the proximal fifth metatarsal bone between 2003 and 2015 were enrolled in this retrospective analysis. Only patients with a minimum follow-up of 12 months were included. The fractures were classified according to Lawrence and Botte (L&B). Data were collected via patient registry, radiographs and a standardized questionnaire (Foot and Ankle Outcome Score = FOAS). For outcome analysis, the nonparametric Mann-Whitney U test was performed and Spearman's rank correlation coefficient calculated.

Results: In total, the functional outcomes of 103 patients suffering from fractures to the proximal fifth metatarsal bone were analyzed. L&B type I fractures (n = 13) had a FAOS score of 91 ± 23, L&B type II (n = 67) presented a score of 91 ± 15 and L&B type III (n = 23) a score of 93 ± 11. Surgically treated patients with an L&B type II fracture had no statistically significant better functional outcome in comparison to conservative management (p = 0.89). Operatively treated L&B type III fractures tended to have a better functional score (p = 0.16). The follow-up time was 58 (min: 15; max: 164) months.

Conclusions: Overall, the functional outcome following fractures to the proximal fifth metatarsal bone is satisfactory. Conservatively treated L&B type II fractures showed an equivalent functional outcome compared to surgical management. Patients with an L&B type III fracture mainly were treated surgically, but difference in FAOS score did not reach level of significance.