Several types of fractures occur to the fifth metatarsal bone of the foot, which can create confusion for patients trying to understand what is the best treatment and if fifth metatarsal fracture surgery is necessary.
The fifth metatarsal bone is the outermost metatarsal bone of the foot. This bone is shaped slightly different than the other metatarsal in that the bone is bowed in two planes. It’s also the only metatarsal bone to have two points of contact with the ground - at the top of the bone (called the head) as well as at the bottom (called the base).
Fifth metatarsal fractures generally occur from trauma to the foot by either a direct force making contact with the bone or a rotational injury causing the bone to break. There are a very powerful ankle and foot tendon that attaches to the base of the metatarsal (called the peroneus Brevis tendon), which can transmit a strong enough force to fracture the bone under certain circumstances. Inversion type of foot and ankle injuries are the most common maneuvers that lead to fracture of the fifth metatarsal (and are also the same injuries that can cause ankle fractures).
The types of fifth metatarsal fracture are:
Head or neck fractures
Fifth Metatarsal Head or Neck Fractures
These fractures occur at the top of the bone in the anatomic region of the metatarsal head and/or neck. The fifth metatarsal head and neck fractures are most common with lower force injuries or direct blunt trauma. Sometimes stubbing the fifth toe can result in this injury. When the fractures occur with more global forefoot injury they may occur with other metatarsal fractures.
The orientation of these fractures lend themselves to instability and may require surgery. Though it's common for foot surgeons to watch these fractures for a week or so to see if they shift out of position, then recommend surgery, each case is different.
The dancers fifth metatarsal fracture has become a universal term for any fifth metatarsal fracture, but foot surgeons generally reserve the term dancers fracture for a specific fracture orientation. A true dancers fracture occurs mostly in the mid-substance of the long metatarsal bone and is oriented obliquely in the shaft of the bone. The fracture line may even spiral and rotate throughout the bone. Sometimes the dancer's fracture that occurs from significant energy can also cause the bone to chip into smaller pieces (called comminution).
Treatment for a true dancers fractures often avoids surgery unless the bone ends are separated or angulated to an unacceptable degree.
The Jones fracture is the most infamous of fifth metatarsal fractures because of their difficulty with healing. The Jones fracture occurs near the bottom of the bone at a specific anatomic location called the metaphyseal-diaphyseal junction. This area of bone, especially on the fifth metatarsal is thought to have less blood supply which is a speculated cause for the prolonged healing that is seen with these injuries.
Jones fractures can be treated with or without surgery, though many feet and ankle surgeons will recommend surgery so long as the patient is active. Athletes with a Jones fracture are almost always recommended surgery. Jones fracture surgery generally involves placing a single surgical screw into the canal of the bone to stabilize it. When Jones fractures are treated without surgery, casts up to the knee are common for six weeks to three months.
Avulsion Fractures of the Fifth Metatarsal
The avulsion fracture is by far the most common fifth metatarsal fracture. They occur at the bottom-most portion of the bone. They are frequently confused with Jones Fractures by patients as well as doctors, so much so that they are also called pseudo-Jones fractures.
They are term avulsion fracture because they occur from a portion of the bone being pulled off (or avulsed) from an over pulling off the strong tendon onto this bone. The avulsion fracture may be incomplete involving a portion of the bone, or it may fully break a segment off of the bone. Sometimes the injury can be quite violent causing the bone to fracture into small pieces.
Most avulsion fractures of the fifth metatarsal do not undergo surgery, rather are treated with protective immobilization with fracture boots/or shoes. When the bones are unacceptable separated, angulated and/ or the fracture displaces its joint surface fifth metatarsal fracture surgery may be necessary.