Fractures of the fifth metatarsal base, the long bone on the outside of the foot, are among the most common injuries treated in foot fracture surgery. Despite being frequently encountered, these fractures continue to create confusion among orthopedic surgeons due to multiple overlapping classification systems and evolving definitions since their first description by Jones in 1902.
In a recent evaluation, members of the American Orthopaedic Foot & Ankle Society (AOFAS) were surveyed to assess how consistently these fractures are classified and managed today. The results shed new light on the reliability of current classification systems and the trends in treatment preferences among experienced orthopedic foot and ankle specialists.
The Challenge of Classifying Fifth Metatarsal Base Fractures
The fifth metatarsal base fracture has long been debated due to its proximity to the midfoot fracture region and the complex anatomy of the lateral foot. Historically, the Jones fracture, first introduced over a century ago, referred to a specific break between the metaphyseal and diaphyseal regions of the bone.
Over time, new zone-based classification systems were developed to better define fracture patterns and guide foot fracture surgery decisions. However, even with these updates, many orthopedic surgeons found inconsistencies when identifying exact fracture types on radiographs.
The latest classification distinguishes fractures as either metaphyseal or meta-diaphyseal, but awareness and adoption of this newer system still vary among practitioners.
Study Overview
To better understand the reliability of these classification systems, a study surveyed AOFAS members and provided radiographs of 18 fifth metatarsal base fractures. Surgeons were asked to:
- Identify the presence of a Jones fracture
- Classify the fractures by zone and metaphyseal/meta-diaphyseal designations
- Share their management preferences for different fracture types
A second survey, sent three weeks later, tested intrarater reliability, whether the same surgeon would classify the same fracture consistently over time.
Key Findings
A total of 223 orthopedic surgeons participated in the initial survey, with a median of 12 years in practice (ranging from 0 to 50 years). Of these, 80 surgeons completed the follow-up survey.
The study found:
- Interrater reliability (agreement between different surgeons) was moderate for Jones and zone classifications but substantial for the newer 2-zone metaphyseal/meta-diaphyseal system.
- Intrarater reliability (consistency by the same surgeon) was strong, with median kappa values of 0.78 for Jones, 0.75 for zone, and 0.78 for metaphyseal/meta-diaphyseal classifications.
- 70% of surgeons treat zone 2 and zone 3 fractures similarly.
- About 60% consider acute symptomatic Jones, zone 2, or zone 3 fractures as operative cases, meaning many of these injuries are candidates for foot fracture surgery in otherwise healthy patients.
What This Means for Surgeons and Patients
According to Dr. Eitan Ingall, the findings highlight the growing recognition that a simpler, 2-zone system may be the most practical and reliable classification method currently available.
“Consistency in diagnosis is critical for guiding appropriate treatment,” explains Dr. Ingall. “When orthopedic specialists can classify fractures with greater reliability, it ensures that patients receive standardized, evidence-based care, reducing variability in outcomes.”
For patients, this translates to more predictable management decisions. Understanding whether a fifth metatarsal fracture falls into a “metaphyseal” or “meta-diaphyseal” category can influence whether foot fracture surgery is recommended or if conservative treatment is appropriate.
Moving Toward Consensus
Despite over a century of research, the Jones fracture remains a topic of discussion among orthopedic professionals. However, the data suggest that simplifying the classification into two primary zones could help reduce diagnostic confusion and improve communication across the field.
As Dr. Ingall notes, “This study reinforces the need for continued education and consensus around fifth metatarsal and midfoot fracture classifications. The more reliable our systems become, the better we can align treatment decisions and improve patient outcomes.”
Conclusion
The study provides valuable insight into the reliability and practicality of current fifth metatarsal base fracture classifications. With substantial interrater agreement and consistent management preferences among AOFAS members, the 2-zone metaphyseal/meta-diaphyseal classification emerges as a strong candidate for standard use.
As orthopedic practice evolves, ongoing collaboration and clarity in classification will remain key to ensuring high-quality, consistent care for patients with midfoot fractures and fifth metatarsal base fractures.