Freiberg infraction (osteonecrosis of the metatarsal head)
Freiberg infraction is a condition that affects the metatarsal bones of the foot. It most commonly affects the second metatarsal (the bone underneath the second toe) but it can also affect the 3rd or 4th metatarsal. Essentially the rounded end or ‘head' of the metatarsal bone collapses and flattens out. Typically, it occurs in young female athletes between the ages of 12 and 15. However, it can occur at any age in either males or females. Non-athletes may be affected; however, Freiberg infraction is more common in individuals engaged in activities that involve repetitive impact on the feet including soccer, running and dancing.
How it occurs
The development of Freiberg infraction is not completely understood. The condition may be due to loss of blood supply around this area and/or mild injury to the bone from repetitive activities that stress the area.
Signs and symptoms
The symptoms may begin gradually and worsen over time. Most individuals describe a dull ache in the forefoot. Freiberg is usually only on one side but can be present in both feet. The pain tends to worsen with activities that bend the toes. The area where the base of the toe meets the metatarsal may be painful to the touch. Occasionally, the pain is severe enough to cause a limp.
Diagnosis
A doctor will ask you about the symptoms and examine the foot. The physician may also get x-rays of the foot if he feels Freiberg infraction is likely.
Treatment
The initial treatment depends on how severe the symptoms are. Most athletes need to rest the affected area of the foot by refraining from irritating. The physician may recommend casting the foot and/or using crutches if symptoms are severe. Custom shoe pads or inserts can take pressure off the metatarsal. These may be worn for an extended period of time to help with the long-term pain and healing.
Rarely, pain persists despite conservative treatment with rest, casting and/or crutch use. Individuals with persistent pain which limits their activities may need surgery to remove loose fragments of bone, restructure the bone or, occasionally, to remove the end of the bone.
Returning to activities and sport
Return to sports is permitted when the patient can tolerate impact activities without pain while wearing a custom insert in the shoe.