Adequate union rates for the treatment of acute proximal fifth metatarsal fractures

PURPOSE: To compare the bone healing, clinical, and return to daily activity outcomes after either surgical or conservative management of acute zone 1, 2, and 3 fifth metatarsal fractures. METHODS: A literature search was performed to identify studies published from the earliest record to January 2019 using EMBASE (Ovid), MEDLINE via PubMed, CINAHL, and Web of Science. All articles assessing clinical outcomes of acute proximal fifth metatarsal fractures were included. Bone healing and clinical outcomes were thereafter calculated using a simplified pooling method. RESULTS: Thirty-two articles comprising of a total of 1,239 fractures were included, of which one was a randomized controlled trial, seven were prospective studies, and 24 were retrospective studies. 627 zone 1 fractures demonstrated union rates of 93.2% following conservative treatment and 95.1% following surgical treatment. Conservatively managed zone 1 fractures were displaced 49.5% of the time, compared to a rate of 92.8% for the surgically treated cases. For Jones’ (zone 2) fractures, bone healing outcomes of conservative versus surgical treatment showed union rates of 77.4% versus 96.3%, refracture rates of 2.4% versus 2.1%, and mean time to union of 11.0 weeks versus 9.4 weeks, respectively. Only ten proximal diaphyseal (zone 3) fractures were reported, with a mean return to work of 8.2 weeks. CONCLUSION: Acute zone 1 fractures are preferably treated conservatively as similar union rates were found after both conservative and surgical management. In contradistinction, acute zone 2 fractures demonstrate higher union rates and faster time to union when treated surgically. The outcomes of acute zone 3 fractures are rarely reported in the literature, so treatment recommendations remain unclear. Further research of proximal fifth metatarsal fractures is warranted to provide more definitive conclusions, but current findings can aid surgeons during the shared clinical decision making process. LEVEL OF EVIDENCE: IV. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00167-020-06072-8) contains supplementary material, which is available to authorized users.