Key Insights On Treating Freiberg’s Infraction

Bob Baravarian, DPM, and Rotem Ben-Ad, DPM

Avascular necrosis of the metatarsal head is known as Freiberg’s infraction and most commonly occurs in the second metatarsal. It is more prevalent in women and the condition most often manifests in the adolescent years between the ages of 11 and 17.1

   Most agree that the cause of this osteochondritis is a combination of both traumatic and vascular insults.1 For example, any biomechanical issue that may cause increased loading of the second metatarsal may result in repetitive stress to the metatarsal. Hallux valgus, hallux rigidus or an elongated second metatarsal can all be contributing factors. Some even hypothesize that high heel shoes worn by women may result in increased stress incurred by the second metatarsophalangeal joint (MPJ). In addition, any vascular compromise to the vessels supplying the metatarsal head and neck may result in necrosis of the bone.

   Patients with Freiberg’s infraction will typically complain of pain with activity. Ambulation either barefoot or in high heel shoes may exacerbate this. Clinically, tenderness upon compression and range of motion of the joint is evident. Swelling is usually present as well. The patient may or may not exhibit limitation of motion of the joint depending on the stage of the disease process.2

   Although first-line imaging for diagnosis is plain radiographs, these may prove to be inconclusive in the early stages of the disease. The earliest changes on radiographs include widening of the joint space. The metatarsal may appear osteopenic due to a hyperemic response. Eventually, sclerosis is visible with flattening of the metatarsal head. Loose bodies may also occur later on as well as central depression of the metatarsal head. Severe joint space narrowing and arthrosis characterize end-stage Freiberg’s infraction.1,2

   Magnetic resonance imaging (MRI) is a useful tool in evaluating the condition of the joint before plain radiographic changes are visible. In general, weighted T2 images would reveal increased signal intensity. The T1 images would display a decrease in signal intensity. In addition, subchondral fractures can be apparent on MRI. This finding, combined with notable bone marrow edema, is highly suggestive of early stages of infraction.4 Later stage findings include flattening of the metatarsal head with subchondral sclerosis and little to no marrow edema.4

A Closer Look At The Treatment Options

Immobilization with limitation of activity is paramount in the early stages of the disease. One may augment conservative treatment with non-steroidal anti-inflammatories, a bone stimulator or physical therapy modalities such as ultrasound. The ideal length of immobilization should be four to six weeks and return to activity should be gradual thereafter.2

   The most simple surgical approach to early-stage Freiberg’s disease is a cheilectomy with cleanup of the joint and removal of any osteophytes. If necessary, subchondral microfracture of the damaged cartilage can promote angiogenesis and fibrocartilage formation.5 Although most surgeons reserve cheilectomy for early-stage disease, some studies have shown no difference in outcomes between debridement with microfracture and dorsal crescentic osteotomy in patients with late-stage Freiberg’s infraction.6

   Core decompression is another fairly simple adjunct to the treatment of avascular necrosis. Use a small Kirschner wire to drill multiple holes in the metatarsal head. This leads to a decrease in the intra-osseous pressure that contributes to the painful symptoms. The drilling also allows revascularization of the necrotic tissue prior to any noted structural transformations.7

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