Proximal 5th Metatarsal Fractures 

The fifth metatarsal is a long  bone in the foot that connects the fifth toe to the midfoot/hindfoot.  This is one of the most frequently fractured bones in the body.  Luckily, the vast majority of these fractures heal quickly, with minimal intervention.  Depending on the location of the fracture, however, problems can arise.

Proximal 5th metatarsal fractures are classified according to the location of the injury as well as how the injury occurred.  Fractures at the very base of the metatarsal are usually classified as “avulsion” type fractures.  Acute fractures approximately 1-2 cm from the base of the metatarsal are classified as “Jones fractures,” and fractures distal to this are usually considered “stress” fractures.

5th Metatarsal Avulsion Fractures

5th Metatarsal Avulsion FractureThese acute injuries are frequently associated with a twisting injury to the ankle and are occasionally misdiagnosed as ankle sprains.  Even with misdiagnosis these fractures tend to heal.  Typically, treatment includes a walking boot or stiff soled shoe with early weight bearing using crutches or a cane as necessary.  Occasionally, patients may require some physical therapy after the bone is healed.  

This type of fracture very rarely requires surgical intervention.  Surgery is indicated for persistant symptoms despite adequate conservative treatment.  Infrequently, the fracture will displace significantly.  Even with significant displacement and minimal evidence of healing on x-ray, these fractures usually do not require surgery.

 

Jones Fractures

Acute Jones FractureA Jones fracture occurs approximately 1.5 to 2 cm distal to the tip of the proximal 5th metatarsal.  These injuries occur as a result of indirect force and the mechanism includes axial loading and rotation of the foot.  The acute onset of symptoms and mechanism of injury distinguishes the Jones fracture from the proximal 5th metatarsal stress fracture (see below).

Jones fractures can be difficult to treat.  Conservative recommendations include cast immobilization and non-weight bearing.  Because of the unique nature of the blood supply to this part of the fifth metatarsal, healing can be delayed (up to 3 months) and there is a relatively high incidence of non-healing of these fractures (fracture non-union). 

Jones Fracture after screw fixationBecause of the possibility of delayed healing or non-union, Jones fractures are frequently treated operatively, particularly in professional athletes and other high-demand individuals.  Some authors suggest that these injuries should be routinely treated with surgery in most patients due to more predictable healing and quicker return to activity.

Surgery involves percutaneous screw placement into the bone across the fracture site (see video below).  Frequently bone marrow concentrate is injected into the fracture site as well to stimulate healing.  Patients may bear weight immediately in a cast brace and bracing is continued until bony healing is evident, usually around 6 weeks.  High demand athletes can frequently return to their sport at 8-12 weeks after surgery.  

 

 

Proximal 5th Metatarsal Stress Fractures

5th Metatarsal Stress Fracture

Healed 5th Metatarsal Stress Fracturerunners and military recruits.     Occasionally in these individuals, the day to day stress that the bones in their feet experience becomes overwhelming, and the bone can fracture as a result of this stress. Foot pain  gradually increases as the stress fracture progresses and eventually, weight bearing activity can become extremely painful.

These injuries arise gradually and often occur in runners and military recruits.  The day to day stress experienced by the bones of the foot in these individuals can lead to fatigue "failure" of the bone with ultimate fracture.

5th metatarsal stress fractures occur in a similar area to Jones fractures, occasionally more distally.  They are subject to the same limitations in blood supply and, because they are frequently long standing by the time medical care is sought, delayed and non-unions are common.

 Treatment includes cast immobilization and non-weight bearing.  If an established non-union is apparent on x-ray, surgical treatment is indicated.  Occasionally, patients will opt for surgical treatment upon diagnosis.  The technique and post-operative course is similar to that of Jones fractures.

Click below to view Dr. McWilliam's technique for operative fixation of a Jones fracture.