Freiberg Disease

Synonyms: Freiberg's infraction

It is difficult to ascertain the true incidence of Freiberg disease as many cases are asymptomatic, and others may resolve spontaneously before seeking treatment.
Most series in the literature have small numbers.
Occurs during the growth spurt at puberty. Most commonly found in young females with a ratio of 1:5 - M:F.²
It is also more common in patients whose 1st metatarsal is shorter than the 2nd metatarsal, which increases the weight on 2nd metatarsal head.

The initial injury as described by Freiberg was thought to be repetitive stress with microfractures at the junction of the metaphysis and the growth plate.
The fractures deprive the epiphysis of adequate circulation, and there is avascular necrosis of the metatarsal head.
However, despite much subsequent research, the true aetiology remains elusive and it is now thought to belong to a group of related diseases involving growth disturbances of the epiphysis or apophysis, collectively termed the osteochondroses.³

• Pain in the forefoot, usually localized to head of the second metatarsal.
• Usually this is associated with physical activity.
• Wearing high heeled shoes makes it worse.
• There may also be localized swelling and stiffness in the metatarsophalangeal joint.
• A limp may be visible.

A small effusion may be palpable and a callus may be seen underneath the affected metatarsal head.

Plain x-ray appearance

Oblique views may be useful to appreciate subtle changes early in the disease.³

• Initially the joint space is widened.
• Then, much later, it narrows & irregular bony surfaces, sclerosis, & bone spurs at margins give the appearance of osteoarthritis.
• The metatarsal head becomes irregular, widened, and flattened at the articular surface.

Magnetic resonance imaging

MRI has been advocated as useful for preoperative evaluation, especially if an osteotomy is planned.

• Synovitis
• Stress fracture
• Osteosarcoma
• Morton neuroma

• Stage I - The earliest sign is fissuring of the epiphysis. X-ray changes at this stage may be so subtle that they are missed with routine pictures.
• Stage II - Later central depression of the articular surface becomes evident as subchondral cancellous bone is resorbed. The articular cartilage hinges on an intact plantar bridge.
• Stage III - The central depression is seen to be resulting in medial and lateral projections at the margins. The plantar hinge remains intact at its plantar isthmus.
• Stage IV - This stage demonstrates that the central portion has sunk below the surface and is free of the plantar hinge, thus becoming a loose body. Fractures of the medial and lateral projections are present, with folding of the projections over the central loose body.
• Stage V - The final stage shows marked flattening and deformity of the metatarsal head with secondary degenerative changes. The central loose body may have been resorbed at this stage. The shaft of the metatarsal becomes thickened and dense.

Although originally described over 85 years ago, Freiberg disease remains controversial as to the most appropriate treatment. Most would advocate an initial period of conservative measures.

General measures

• Supportive foot wear with a metatarsal bar or pad placed beneath the involved bone.⁵
• Reduce weight-bearing activities for four to six weeks.
• If symptoms are severe, consider immobilizing foot in short leg walking cast until symptoms subside, usually in 3-4 weeks.

Surgical

This is rarely used, but the most usual indication is failure of conservative treatment. Options include:

• Debridement
• Bone grafting
• Osteotomy⁶
• Arthroplasty⁷