Fifth Metatarsal Fractures: When Should You Operate?

Fifth metatarsal fractures are a common pathology in my practice, sometimes with two or three presenting per clinic session. How we treat these fractures depends on a number of factors such as fracture location, displacement, patient age, activity level and medical co-morbidities. In this blog, I'll go over the different kinds of fifth metatarsal fractures and my general treatment algorithm.

The most common fifth metatarsal fractures that I encounter are generally those of the base and distal shaft. First, we’ll discuss base fractures and the treatment options for these injuries. Fifth metatarsal base fractures are classified into three zones. Zone 1 fractures, also called “pseudo-Jones” fractures, are the most common of these base injuries. They are typically secondary to the pull of the peroneus brevis tendon or pull from the lateral band of the plantar fascia. Nonunion is uncommon and I rarely operate on these in minimally to non-displaced clinical scenarios. My treatment is typically six-to-eight weeks in a walking boot with gradual return to normal shoe gear and activity based on clinical and radiographic signs of improvement and healing.¹ In rare cases where surgery is indicated, such as with rotational displacement or skin tenting, I prefer a hook plate construct with lag screw to reduce the fragment. Alternatively, I have used a tension band construct when the fragment is not large enough for a lag screw.

Zone 2 injuries or “Jones fractures” are the fractures typically associated with surgical intervention. These fractures at the metaphyseal-diaphyseal junction are notorious for non-healing secondary to the anatomic watershed that exists in terms of blood flow to that area of the bone. In a young, healthy, athletic population I will usually recommend surgical intervention and typically use a non-cannulated partially threaded 5.5 mm screw for fixation.² Additionally, I will use autologous bone marrow aspirate concentrate (BMAC) at the time of surgery and inject into the area adjacent to the fracture before screw fixation. In cases where we elect to not pursue surgical intervention, I will order a bone stimulator and pursue non-weight bearing for six weeks before weight bearing in a CAM boot until achieving clinical and radiographic healing. Important to note that in my experience, up to 33 percent of these non-operatively treated fractures can lead to refracture. This is something I discuss with all patients with this injury who elect to not proceed with surgical fixation.

Zone 3 injuries are fractures involving the proximal diaphysis which are also at higher risk for non-healing and associated with a cavovarus foot type. While there is not much literature on these injuries to demonstrate definitive superiority of surgical versus non-surgical treatment, similar to Jones fractures I will also employ a more aggressive approach in electing to pursue surgical intervention in a young, athletic population. In this pursuit, the goal is faster return to activity and sport as well as a faster healing time given the diaphyseal nature of these fractures.³

Fifth metatarsal shaft fractures with greater than ten degrees of plantar angulation or three millimeters of displacement in any plane require operative management when closed reduction proves insufficient.⁴ It is important to note that these fractures tolerate a high degree of angulation before necessitating surgical intervention. I will typically employ a bridge or neutralization plate construct for fixation of these fractures and have a low threshold for bone grafting in the event of a void that requires backfilling.⁴

Fifth metatarsal fractures are common injuries that can be treated both surgically and conservatively. I hope this article has shed some light on when to pursue various treatments for these injuries.

Dr. Ali Rahnama is a fellowship-trained foot and ankle surgeon and an Assistant Professor at the Georgetown University School of Medicine in Washington, D.C. You can follow him on Instagram @DrAliRahnama for interesting cases and educational material. 

References

1. Shahid MK, Punwar S, Boulind C, Bannister G. Aircast walking boot and below-knee walking cast for avulsion fractures of the base of the fifth metatarsal: a comparative cohort study. Foot Ankle Int. 2013;34(1):75-79.

2. Thevendran G, Deol RS, Calder JD. Fifth metatarsal fractures in the athlete: evidence for management. Foot Ankle Clin. 2013;18(2):237-254.

3. Rikken QGH, Dahmen J, Hagemeijer NC, et al. Adequate union rates for the treatment of acute proximal fifth metatarsal fractures. Knee Surg Sports Traumatol Arthrosc. 2021;29:1284–1293.

4. Bowes J, Buckley R. Fifth metatarsal fractures and current treatment. World J Orthop. 2016;7(12):793-800.