Essential Insights On Treating Fifth Metatarsal Fractures

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By Nicholas Romansky, DPM, and Todd Becker, DPM
However, even with non-weightbearing immobilization, many of theses fractures will go on to nonunion after 10 or 12 weeks with rates as high as 28 percent being reported in the literature. Type II fractures also tend not to heal and many go on to non-union after the eight to 12 weeks of cast immobilization. Kavanaugh and Delee advocated percutaneous insertion of a cannulated screw, which one would place longitudinally down the intramedullary canal, as the primary treatment of choice for active patients with Type I fractures and all Type II fractures.3,8 They noted that active patients tend to have a much faster recovery from this surgery and can begin earlier weightbearing (usually within days) with cross-training. Other Insights On The Treatment Of Jones Fractures Portland, et. al., found union rates of 6.2 weeks for acute Jones fractures and 8.3 weeks for stress fractures treated with intramedullary screw fixation. In their study, all 22 of the patients achieved complete union.9 In 1999, Pietropaoli found no biomechanical difference between the use of 4.5 mm malleolar screws and 4.5 mm partially threaded cannulated screws.10 In 2001, Shah determined there is no difference in fixation rigidity based on the size of the partially threaded cannulated screw used (4.5 mm vs. 5.5 mm) and may actually increase the risk of intraoperative or postoperative fracture.11 Conversely, Kelly, et. al., found that fifth metatarsal fractures can accommodate 6.5 mm screws and that they had greater pull-out strength and greater purchase than 5.5 mm screws.12 They also found that using a large screw did not result in greater fracture stiffness but did result in a high rate of fracture with insertion. They suggest using a 6.5 mm screw but recommend using smaller screws for canals with diameters less than 5 mm. Husain and DeFronzo compared the use of intramedullary screw fixation with bicortical screw fixation.13 They found a greater resistance to load failure in the bicortical screw when they compared it to intramedullary screw fixation. However, there was also a high propensity for failure at the medial aspect of the screw’s exit through the stress riser. Other ORIF modalities include tension banding, percutaneous pinning and inlay bone grafting. Torg described the use of inlay bone grafting as the treatment of choice for stage II and III stress fractures.4 Tuberosity Fractures: What You Should Know Fractures to the styloid process occur proximal to the fourth/fifth intermetatarsal articulation and are believed to be the result of tensile mediated avulsion by the lateral cord of the plantar aponeurosis and/or peroneus brevis. Stewart classified these fractures based on their anatomic site and articular involvement.6 Type I fractures correspond to the aforementioned Jones fracture. Type II is an intraarticular fracture of the base of the metatarsal. Type III is an extraarticular fracture of the styloid process. Type IV is an intraarticular comminuted fracture of the metatarsal. Type V represents an injury to the apophysis in children. In adolescents, it important to remember that the apophysis is also the site of a secondary growth plate and may actually be apophysitis. One can easily determine this by the presence of a radiolucent line parallel to the shaft of the metatarsal. This apophysis is most common among girls aged 9 to 11 and boys aged 11 to 14. It disappears two to three years after it first appears. One must also be aware of the possibility of a possible secondary ossicle that mimics symptoms of a base fracture. It is important to obtain contralateral films to rule out an os vesalianum or os peroneum. Proximal fifth metatarsal fractures typically demonstrate minimal displacement and heal very well conservatively with a short leg cast for two weeks followed by a progressive return to shoe gear for another two to four weeks. Joint displacement greater than 5.0 mm, the presence of a lateral prominence, comminution or delayed union are all indications for ORIF with intramedullary screws, tension band wiring or fragment excision with tendon repair (if the fragment is small). In a frozen cadaveric study, Husain, et. al., compared 4.0 mm partially threaded screws to two 0.062 K-wire tension band wirings.

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