Intramedullary Screw Fixation for Chronic Proximal Fourth Metatarsal Stress Fractures: A New Technique for the Fourth Metatarsal “Jones”

Abstract

In athletes, conservative treatment of proximal fourth metatarsal stress fractures can result in deconditioning, delayed return to sport, disability, and recurrence of the fracture. Although nonoperative care has been advocated for such an injury, internal fixation can provide more rapid and reliable healing in athletes. However, until now, bone grafting with or without dorsal plate fixation was the only surgical option. We have developed a means of inserting a 4.5-mm cannulated intramedullary screw as a safe approach that can promote complete healing and timely return to sport. This fixation shows healing similar to intramedullary screw fixation of the fifth metatarsal Jones fracture. We term this the ''fourth metatarsal 'Jones' fracture'' and treat it in a similar manner as the fifth. The senior author has treated 8 athletes surgically with this approach for chronic nonunion of fourth metatarsal stress fractures. Clinical and radiographic assessments up to 10 years after surgery show 100% healing without fourth tarsometatarsal joint degeneration. Subjective reporting indicates 100% healing in as little as 6 weeks. No postoperative complications (screw failure, persistent sclerosis, refractures, or arthritis at the tarsometatarsal joint) have occurred. This technique results in reliable, effective, fast healing of chronic fourth metatarsal stress fracture sites in competitive athletes. However, the technique is technically demanding.The concept of a stress fracture was first described by the Prussian military physician, Breithaupt, in 1855. 1 Since then, numerous studies have highlighted the relatively high incidence of stress fractures in competitive athletes and others who undergo rigorous training, such as military recruits at boot camps.Stress fractures of the metatarsals are the second most common type of fracture that athletes sustain, 2 accounting for approximately 10% of all overuse injuries. 3 Some reports say this is as high as 28%. 4 Athletes who repeatedly perform high levels of running and jumping activities are particularly predisposed to metatarsal stress fractures, as the injury is associated with a marked increase in loading forces applied to the foot. 5 Despite this, the frequency with which such fractures occur is not well documented. 5 Chuckpaiwong et al 2 reported that 10% to 20% of all stress fractures in athletes are metatarsal fractures, which corroborates earlier studies. [6][7][8][9] Although all stress fractures are precipitated by excessive force or strain without adequate rest periods, the etiology for fourth metatarsal stress fractures remains unclear. 10-12 Studies have documented numerous factors that may predispose an athlete to stress fractures, 5,10,11 but the primary cause seems to be related to muscle fatigue transmitting excessive forces to the underlying bone. 10 Strength gains in bone (bone remodeling) lag behind strength gains in muscle. 13 Regional vascularity may also contribute to the pathomechanics, as the fourth metatarsal's nutrient artery is compressed during weigh...