A Closer Look At Fixation For Fifth Metatarsal Fractures
- Volume 25 - Issue 9 - September 2012
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The most common fixation technique the lead author uses is a tubular plate with 2.7 mm cortical screws. Surgeons can accomplish reduction via distraction of the fifth toe to restore the length and applying a bone clamp to reduce the medial displacement in the diaphysis. One can use fluoroscopy to confirm reduction. The problem with the bone clamp is that it blocks lateral application of the plate so the lead author will insert a 0.062 K-wire through the fracture to maintain a reasonable degree of reduction and in a direction so it does not interfere with plate application.
One subsequently removes the clamp and applies the plate laterally, ensuring enough distal placement so the surgeon can insert at least one screw through the head depending on the characteristics of the fracture. The plate should also extend proximal enough so one can anchor at least two screws proximal to the fracture. You can usually accomplish this with a five- or six-hole plate. T-plates or L-plates also provide the ability to insert additional screws into the metatarsal head. Locking plates also enable the surgeon to insert two or even three screws distally, and locking plates are indicated in soft osteoporotic bone.
Many times, the fracture spike is so narrow that one cannot use an interfragmentary screw. Sometimes, the surgeon can use a smaller diameter 2.0 mm or 2.4 mm cortical screw to achieve interfragmentary compression but one should insert this screw prior to plate application. The tubular plate will function as a neutralization plate.
Essential Insights On Treating Jones Fractures
The Jones fracture occurs 1.5 to 3.0 cm distal to the tuberosity and at the articular surface of the fourth and fifth metatarsals.4 Given the poor healing or refracture that can occur with Jones fractures when clinicians opt for immobilization only, surgery is often an initial treatment, especially in active patients and athletes.
The Jones fracture lends itself to surgical repair because good exposure is easy to achieve and there is adequate bone both distal and proximal to the fracture to secure fixation modalities.
There are two likely options when surgery is the primary initial procedure. The first option is closed reduction with percutaneous fixation. We have found it easy to work with cannulated systems for these fractures. After reducing the fracture, insert a wire from the cannulated set through the base of the metatarsal across the fracture into the medullary canal. To avoid inadvertent perforation of the cortex, tap the wire and slowly advance it in the medullary canal with a small mallet. One can perform overdrilling as needed.
Proceed to make a small incision at the base of the metatarsal and insert the cancellous screw. The screw diameter is up to the surgeon. However, in a clinical and biomechanical study, Reese and colleagues determined that surgeons can achieve the best results when using the largest diameter screw that can fit in the medullary canal.5 This can be in the range of 4.0 mm to 6.5 mm, depending on the size of the bone.
Prior to surgery, one should measure the width of the medullary canal on the X-ray to determine the appropriate diameter screw. Also bear in mind that many fifth metatarsals have lateral diaphyseal bowing, which may not lend itself to using a long screw. In these cases, the tip of the screw may contact the distal medial surface of the metatarsal, resulting in displacement of the lateral portion of the fracture as one advances the screw. In the presence of lateral bowing, the lead author uses the shortest, widest screw possible for the Jones fracture.