The Proximal 5th Metatarsal Fracture: A Spectrum of Misunderstood Fractures

Abstract

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: Several different types of 5th metatarsal fractures exist and are treated with various methods of immobilization, weight bearing restrictions, and occasionally operative procedures. The purpose of this study was to evaluate the differences in clinical and radiographic outcomes between pseudo-Jones fractures (Zones 1 and 2 of the 5th MT base), True Jones fractures (Zone 3), and 5th MT shaft fractures. Methods: This was a retrospective cohort study of patients presenting to a single large, urban, academic medical center with any 5th MT fracture between 2012 and 2022. Inclusion criteria for this analysis included patient follow up until there was evidence of radiographic healing, clinical healing, or duration greater than one year following injury. Radiographs obtained at the initial presentation were reviewed and fracture patterns were categorized as either Zone 1, Zone 2, Zone 3, or Shaft. Linear regression models were used to evaluate the effect of fracture type on the duration of healing when controlling for age, sex, BMI, smoking status, and history of diabetes. 1,279 patients with 5th metatarsal fracture met the inclusion criteria and were included in the analysis (mean age 49.2 +/- 17.9 years). Overall, 5.2% were treated in a splint or cast, 67.5% in a CAM boot, 20.3% in a hard sole shoe, and 7.0% without immobilization. Results: 31.2% of patients were non-weight bearing, 8.1% partial weight bearing, and 60.7% weight bearing as tolerated. There was no difference in time to radiographic union (p=0.946) or time to clinical healing (p=0.520) between any of the fracture types. Similarly, there was no difference in the proportion of patients with incomplete radiographic healing at 6 months (p=0.310) and at 1 year after injury (p=0.552) based on the fracture type. Likewise, there was no difference in any clinical or radiographic healing parameter based on fracture type for patients treated operatively. Based on linear regression model, there was no difference in the time to clinical or radiographic healing when controlling for confounding factors. Conclusion: All commonly occurring 5th metatarsal fractures, including those of both the metatarsal base and the shaft, demonstrate similar times to clinical and radiographic healing.