Optimal Treatment and Management of Proximal Fifth Metatarsal Fractures

Abstract

Category: Midfoot/Forefoot Introduction/Purpose: Proximal fifth metatarsal fractures (PFMF) are among the most common fractures of the foot, and may be subdivided into tuberosity avulsion fracture, Jones fracture, and proximal diaphyseal fracture. However, for Jones fractures and proximal diaphyseal fractures optimal treatment is still debated in literature. The Torg criteria are used in deciding to treat surgically or conservative, whereby Torg type I and II indicates conservative treatment, and type III indicates surgical treatment. Yet failure rates of both management options vary and derive from small study groups. The aim of this study was to compare failure rates after surgical- and conservative treatment of Jones fractures and proximal diaphyseal fractures, to evaluate the incidence of treatment failure, and to assess factors associated with healing difficulties of PFMF. Methods: A total of 1,133 adult patients that were diagnosed and treated for PFMF between 2005 and 2015 in a tertiary care foot and ankle referral center were included. Retrospective chart review recorded patient demographics, suspected risk factors for impaired healing of PFMF (rheumatoid arthritis, diabetes mellitus, osteoporosis, nutritional and hormonal disorders, foot deformities, (neuropathic) arthropathy of the foot and/or ankle and peripheral neuropathy of the lower extremity), and treatment indication. Multivariable logistic regression analysis was used to determine factors associated with healing difficulties. Propensity score matching was used to minimize selection bias between treatments in Jones fractures and proximal diaphyseal fractures. Results: In total, 489(43.2%) patients were diagnosed with a tuberosity avulsion fracture, 391(34.5%) patients with a Jones fracture and 253(22.3%) patients with a proximal diaphyseal fracture. In the tuberosity fracture group, a nonunion was found in 5.3%(25/473) of the patients treated conservatively and in 0%(0/16) treated operatively. For the Jones fractures and proximal diaphyseal fractures the non-union rate for conservative treatment was 10%(35/337) and 5.9%(14/238), and for surgical treatment 11%(6/54) and 0%(0/15), respectively. No independent risk factors for complicating the healing process of PFMF were identified. With propensity score matching, 37 patients treated operatively were matched to 37 patients undergoing conservative treatment. The risk for a nonunion was lower in the operative group compared to the conservative treatment group (relative risk 0.8, P=0.006). Conclusion: In this propensity-matched cohort, surgical treatment for Jones fractures and proximal diaphyseal fractures were associated with better fracture healing compared to conservative treatment. In addition, no factors were found to be associated with healing difficulties of proximal fifth metatarsal fractures.