Jones Fractures: Surgical Tips and Pearls

Jones fractures are a type of fracture at the diaphyseal-metaphyseal junction of the 5th metatarsal bone, approximately 1.5 cm distally from the base of the 5th metatarsal. This type of fracture is caused by an adduction force of the forefoot, creating tensile stress along the lateral border of the bone. Lawerance et al in 1993 described three fracture patterns at the base of the 5th metatarsal bone:

1. 1. Zone 1 – tuberosity avulsion fractures

1. 1. Zone 2 – Jones fractures

1. 1. Zone 3 – diaphyseal stress fractures including the proximal 1.5 cm of the diaphysis (It should be noted that zone 2 injuries are acute injuries, whereas zone 3 injuries are preceded by prodromal symptoms.)

This blog post will focus on Jones Fractures including surgical tips and pearls. I prefer surgical open reduction and internal fixation of these injuries if the patient is a good surgical candidate for the following reasons:

1. 1. Superior union rate (decreased risk of delayed or nonunions) as compared to nonoperative treatment (source)

1. 1. Earlier return to preinjury activities and sports

1. 1. Patients can bear weight earlier following surgery, as compared to prolonged non-weight-bearing for nonsurgical care.

Surgical Tips and Pearls:

1. 1. Place the patient in a lateral decubitus position and use a thigh tourniquet for hemostasis. If surgery is performed in a supine position, place a bump under the ipsilateral hip to improve visualization of the lateral foot during the surgery.

1. 1. Preoperatively, measure the medullary canal width and length of the 5th metatarsal (proximal to the lateral deviation of the 5th metatarsal bone) as this helps to anticipate the screw size length and width. The screw diameter should be maximized within the diaphyseal canal to improve purchase. A solid core screw seems to provide superior fatigue strength as compared to cannulated screws (comment below on your preferred choice of fixation).

1. 1. Outline the 5th metatarsal medullary canal on the A-P and lateral radiographic views prior to the incision using intraoperative C-arm fluoroscopy.

1. 1. A 1 cm incision is placed 1 cm proximal to the 5th metatarsal base

1. 1. A guidewire is inserted “high and inside” on the 5th metatarsal base -confirm proper placement on the A-P and Lateral views. Once the k-wire pierces the proximal cortex, a mallet can be utilized to advance the wire down the medullary canal of the 5th metatarsal bone.

1. 1. Place the intramedullary screw making sure that the threads cross the fracture site and engage the medial and lateral cortices of the 5th metatarsal bone. According to a cadaveric study published in the Journal of Foot and Ankle Surgery in 2015, a 4.5 mm screw is the smallest diameter screw that should be utilized for this type of surgery. (see source)

1. 1. Post-op course
      -non-WB x 2 weeks with crutches
      -Weight bear as tolerated in CAM boot for 4-6 weeks
      -Weight bear without boot at 6 weeks if the patient can tolerate
      -return to full activity at about 3 months

Non-surgical Treatment Considerations

1. 1. 50% of Jones fractures treated closed either do not heal or refracture once initial healing has occurred.

1. 1. Treatment non-surgically requires at least 6-8 weeks NWB (often times longer), with an increased rate of delayed or nonunion.

1. 1. Nonoperative care is typically reserved for sedentary patients and those with high surgical risks.

1. 1. **Studies have shown that screw fixation heals faster than nonoperative care of these injuries (JBJS- Source).

Torg Classification for Proximal Fifth Metatarsal Fractures

This classification system describes the chronicity of these types of fractures based on the degree of sclerosis adjacent to the fracture on imaging and can assist with treatment planning.

1. 1. Type 1 – Acute fracture demonstrating no intramedullary sclerosis, minimal periosteal reaction, and no widening at the fracture line

1. 1. Type 2 – Delayed union – Fracture line involves both the medial and lateral cortices with periosteal reaction noted. A widened fracture line is noted with adjacent radiolucent (due to bone resorption). Intramedullary sclerosis of bone is developing.

1. 1. Type 3 – Nonunion – There is a wide fracture line with obliteration of the medullary canal by sclerotic bone.

Jone’s Fractures: Conclusion

In conclusion, surgical treatment of Jones fractures of the foot represents a viable and effective approach to address this specific injury. The decision to opt for surgery should be guided by careful consideration of various factors, including the fracture type (Torg Classification), the patient’s medical history, and the patient’s activity level. Surgical intervention, often involving the fixation of the fracture with intramedullary screw fixation, aims to promote optimal alignment and stability, thereby facilitating proper healing and early return to activity. While conservative measures such as casting may be suitable for some cases, surgery offers a more direct and controlled means of addressing the fracture, reducing the risk of complications and promoting a faster return to normal function. However, as with any medical procedure, individualized assessment and thorough consultation with healthcare professionals remain essential to determine the most appropriate course of action for each patient.