Jones Fractures
Jones fractures are fractures of the 5th metatarsal at the metaphyseal-diaphyseal junction, where there is a watershed area of decreased vascularity between the intramedullary nutrient and metaphyseal arteries. Current thought is that the rising rate of Jones fractures among football players is partially caused by the use of flexible, narrow cleats that do not provide enough stiffness and lateral support for the 5th metatarsal during running and cutting. Additionally, lateral overload from a baseline cavovarus foot posture with or without metatarsus adductus and/or skewfoot is thought to contribute to Jones fractures.10 Preoperative radiographs should be evaluated for fracture location, orientation, amount of cortical thickening, and overall geometry of the foot and 5th metatarsal. In elite athletes, the threshold for surgical intervention is decreasing in order to expedite healing and recovery and decrease re-fracture risk. This rationale is based on delayed union rates of 25% to 66%, nonunion rates of 7% to 28%,11 and re-fracture rates of up to 33% associated with nonoperative treatment.12 Nonoperative management is usually not feasible in the competitive athlete, as it typically involves a period of protected weight-bearing in a tall controlled ankle motion (CAM) boot for 6 to 8 weeks with serial radiographs to evaluate healing.
Our preference for surgical intervention involves percutaneous screw fixation with a “high and inside” starting point on fluoroscopy (Figures 2A-2D).
Figures 2A-2D
Figures W4A-W4F
In career athletes, we augment the fracture site using a mixture of bone marrow aspirate concentrate (BMA) (Magellan, Arteriocyte Medical Systems) and demineralized bone matrix (DBM) (Mini Ignite, Wright Medical Technology) injected percutaneously in and around the fracture site under fluoroscopic guidance. Using this technique in a cohort of 25 NFL players treated operatively for Jones fractures, we found that 100% of athletes were able to RTP in the NFL in an average of 9.5 weeks.14 Two patients (7.5%) suffered re-fractures requiring revision surgery with iliac crest bone graft and repeat screw placement with a RTP after 15 weeks. We did not find an association between RTP and re-fracture rate.
The appropriate rehabilitation protocol for Jones fractures after surgery remains controversial and dependent on individual needs and abilities.15,16 For athletes in-season, we recommend a brief period of NWB for 1 to 2 weeks followed by toe-touch weight-bearing in a tall CAM boot for 2 to 4 weeks. After 4 weeks, patients begin gentle exercises on a stationary bike and pool therapy to reduce impact on the fracture site. Low-intensity pulsed ultrasound bone stimulators (Exogen, Bioventus) are frequently used directly over fracture site throughout the postoperative protocol as an adjuvant therapy. If clinically nontender over the fracture site, patients are allowed to begin running in modified protective shoe wear 4 weeks after surgery with an average RTP of 6 to 8 weeks. RTP is determined clinically, as radiographic union may not be evident for 12 to 16 weeks. Useful custom orthoses include turf toe plates with a cushioned lateral column and lateral heel wedge if hindfoot varus is present preoperatively.10 The solid intramedullary screw is left in place permanently.
In our experience, we have found the average re-fracture and nonunion rate to be approximately 8% across all athletes. Our observation that union rates do not appear to be related to RTP times suggests that underlying biology such as Vitamin D deficiency may play a larger role in union rates than previously thought. We have found that most Jones re-fractures occur in the first year after the initial injury, but can occur up to 2.5 years afterwards as well.14 For the management of symptomatic re-fractures and nonunions, the previous screw must be first removed. This can be difficult if the screw is bent or broken, and may require a lateral corticotomy of the metatarsal.
After hardware removal, we advocate open bone grafting of the fracture site using bone from the iliac crest retrieved with a small, percutaneous trephine. Re-fixation should be achieved using a larger, solid screw and postoperative adjuvants may include bone stimulators, Vitamin D and calcium supplemention, and possible teriparatide use (Forteo, Eli Lilly), depending on individual patient profile. In a cohort of 21 elite athletes treated for Jones fracture revision surgery with screw exchange and bone grafting, we found that 100% of patients had computed tomography (CT) evidence of union, with an average RTP of 12.3 weeks.17