Essential Insights On Treating Fifth Metatarsal Fractures

By Nicholas Romansky, DPM, and Todd Becker, DPM
They found the screw construct had greater strength and three times the load resistance of the tension band technique.12 Postoperative treatment includes a walking cast or Cam walker for four to six weeks postoperatively. Can You Spur An Earlier Return To Play For Athletes? In athletes, almost all fifth metatarsal fractures require surgical treatment. Given the high rates of delayed union, non-union or recurring fracture, early surgical intervention via ORIF or intramedullary fixation is strongly recommended. When pursuing these surgical options, the surgeon should ensure the patient is in a supine position on the OR table with the knee maximally flexed and the foot adducted on the surface of the OR table. This key position makes it very easy to place the guide or K-wire through the fracture site. Always aim down and inward to avoid hitting the lateral metatarsal cortex. Early surgical intervention helps avoid deconditioning of the athlete and typical prolonged bouts of immobilization. Modified activity or “relative rest” of activity can begin three days after the procedure. Both of the above options facilitate an earlier return to play for athletic patients. However, one should closely monitor these athletes as the rate of fracture recurrence can be 12 percent or higher. A Primer On Fifth Metatarsal Anatomy A thorough understanding of the anatomy is crucial to the successful treatment of fifth metatarsal fractures due to variations within the metatarsal. The fifth metatarsal is a long bone consisting of a capitum, cervical neck, diaphyseal shaft, a metaphyseal-diaphyseal junction as well as the distinctive tuberosity at the base. Researchers have shown that the narrow distal canal, thicker dorsal and plantar cortices, and lateral bowing of the metatarsal are all potential factors in fixation failure.1 Ligamentous attachment to the fifth metatarsal base includes a portion of the long plantar ligament as well as the short plantar ligament, an interosseous ligament between the fourth and fifth metatarsal bases. Ligamentous attachment also includes the medial, lateral, dorsal and plantar cuboid-fifth metatarsal ligaments. The peroneus brevis and peroneus tertius tendons also insert onto the base of the fifth metatarsal. Along the shaft of the bone is the origin of the three muscles, including the abductor digiti quinti brevis, the dorsal interosseous (which aids in interosseous stability due to its bipennate nature) and plantar interosseous muscles. While most of these muscular attachments play only a limited role in acute fractures, the peroneus brevis has been shown to be a major force in inversion injuries lending to styloid fractures. There is also a slip of the lateral plantar aponeurosis that attaches to the base of the metatarsal. The nutrient artery to the fifth metatarsal enters the shaft at the middle and proximal one-third junction, and divides into a short proximal and longer plantar branch. This network of arteries accounts for approximately 60 to 65 percent of the blood supply to the bone. The other 30 percent comes from the periosteum and 5 percent comes from the joint interface. There is an area of relative avascularity that exists at the juncture of the divergence of the proximal terminal branch of the nutrient artery and the metaphyseal arteries that lends itself to the high non-union rate of Jones fractures. This area tends to become even more avascular once a fracture has occurred due to the increase in cortical thickening and loss of medullary canal. Accordingly, proteins and nutrients necessary for bone healing cannot reach the fracture site, leading to a high rate of non-unions. It is also necessary to have a good working knowledge of the path of the sural nerve when undertaking surgical correction of proximal fifth metatarsal fractures. In 1999, Donley demonstrated through cadaveric dissection that one must give particular attention to the dorsolateral branch of the sural nerve when fixating these fractures due to its proximity to the insertion site of the screw.2 In Conclusion Podiatric physicians commonly see fractures of the fifth metatarsal when treating active patients. Choosing between conservative and surgical treatment is imperative because conservative treatment can sometimes lead to an extremely slow recovery or long-term problems. Both competitive and recreational athletes should be geared to a more rapid recovery.

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