Last Updated on March 20, 2024
Freiberg disease or Freiberg infraction is a rare condition in which the metatarsal head undergoes osteonecrosis. It is an osteochondrosis of metatarsal heads Freiberg disease is osteochondrosis affecting the metatarsal heads. Osteochondroses are a group of conditions that affect phses and epiphysis affecting ossification and may lead to irregularities and degenerative changes of the affected joint/ apophysis.
The condition was described originally by Dr Freiberg in 1914. It is mostly seen in adolescents aged between 13-18 years (Though cases as old as 70 years have been described) and is almost 4-5 times more common in females. It is the only osteochondrosis more common in females.
The metatarsal head is most commonly involved followed by the 3rd. About 10% of cases have bilateral involvement. is only osteochondrosis more common in females.
Most of the cases of infractions are not symptomatic or may resolve spontaneously.
The disease affects females five times more commonly than males.
Causes of Freiberg Disease
In adolescents, Freiberg disease is thought to be a growth disturbance and belongs to the group of the disease called osteochondrosis. Though Freiberg thought trauma was the cause of the condition, the exact etiology has still not been explained.
The process leads to osteonecrosis of subchondral cancellous bone. If the body can restore this, there is a regeneration or recalcification. Otherwise, this leads to subchondral collapse and fragmentation of the joint surface.
Freiberg disease in adults is thought to represent a different process though they have similar radiological features. The primary cause may be vascular or traumatic
- In vascular causes, the primary event is thought to be a direct or repetitive insult to the blood supply of the metatarsal head
- Repetitive or acute trauma is thought to be another reason
Certain patients may be anatomically predisposed due to local, mechanical, vascular, and developmental factors.
Staging of Freiberg Disease
Smillie classification
It is most widely used and is based on radiological changes.
- I – Fissure develops in the ischemic epiphysis. Opposing cancellous bone on either side of the fissure appears sclerotic.
- II – Collapse, central resorption of bone within the metatarsal head causes the subchondral bone to subside.
- III – Peripheral irregularities present. Subchondral bone sinks further into the head, creating peripheral irregularities of the intact joint surface. An isthmus of the articular cartilage on the plantar aspect of the metatarsal head remains intact.
- IV – Osteochondral Loose body.
- V – Flattening deformity and arthrosis. Only the plantar aspect of the metatarsal head where the final isthmus of cartilage fractured retains its original contour. The shaft of the metatarsal becomes thickened and dense.
Presentation of Freiberg Disease
Some patients may remain asymptomatic. The patient usually complains of pain in the forefoot, often localized to the involved metatarsal head region of the foot. Depending on the duration of the affliction, patients may present with gradual onset or acute pain of recent onset or chronic pain that episodically exacerbates. The pain is typically present during activity. There might be associated stiffness. A limp on walking may be present. Some patients may complain of a sensation of a small, hard object under the foot.
On examination, the involved toe may be swollen near the metatarsophalangeal. There may be dorsiflexion of the toe. In long-standing cases, the alignments of the toe may be affected. The range of motion may be affected.
Imaging Studies
Radiographs
Anteroposterior and oblique views are routinely done. Early X-rays in Freiberg disease may show only sclerosis and widening of the joint space but radiographs in a later stage show with the collapse of the metatarsal head. Fragmentation of the head and osteochondral loose bodies may be visible in further stages. [refer to stages of the disease given above]
MRI
Magnetic resonance imaging may assist in the early detection of Freiberg disease when X-rays are normal. Early changes that MRI detects are an edema-like signal localized to the affected metatarsal head.
Treatment of Freiberg Disease
Several patients in stage I-III may resolve spontaneously or with conservative treatment. The patients who do not respond to conservative treatment in the above-listed stages as well as those who fall in stages IV & V require surgery.
The goal of therapy is to rest the joint to allow inflammation and mechanical irritation to resolve.
Nonoperative Treatment
The treatment aims to address the symptoms and minimize epiphyseal deformity and secondary degeneration,
These interventions consist of
- Activity modification/curtailing
- Protected weight-bearing
- Cast, brace
- Customized shoes (stiff-soled shoes with MT bars or pads)
- Drugs
- Antiinflammatory drugs like NSAIDs
Most patients with Smillie stages 1 through 3 respond to conservative treatment and obtain long-term success.
In acute presentations, a simple below-knee non-weight-bearing cast may be sufficient. In nonacute presentations, a weight-bearing cast may be given.
Symptomatic analgesic drugs might be taken. Few physicians recommend steroid injections too.
In patients who do not respond to the medical treatment or those who are in stages IV and V, surgery may be considered.
Operative Treatment
the following options can be considered –
- Simple debridement can be done alone or combined with other procedures including excision of the metatarsal head, hemiphalangectomy, and loose body excision.
- Bone grafting
- Osteotomy
- Dorsal closing wedge osteotomies – Reorienting the intact cartilage on the plantar surface to articulate with the base of the proximal phalanx.
- Shortening osteotomy – To shorten the metatarsal
- Arthroplasty*
- Resection arthroplasty – Involves resection of the base of the proximal phalanx or of the metatarsal head. Not done nowadays
- Total small joint arthroplasty using a silicone prosthesis
- interposition arthroplasty
- Core decompression – Multiple drill holes with K-wire
- Osteochondral plug transplantation
*Arthroplasties, irrespective of the type, are not very useful
In stage I or II grafting and elevation of the collapsed articular surface is recommended.
For advanced lesions, the treatment needs to be individualized.
References
- Talusan PG, Diaz-Collado PJ, Reach JS Jr. Freiberg’s infraction: diagnosis and treatment. Foot Ankle Spec. 2014 Feb;7(1):52-6. [Link]
- Wax A, Leland R. Freiberg Disease and Avascular Necrosis of the Metatarsal Heads. Foot Ankle Clin. 2019 Mar. 24 (1):69-82. [ Link].
- Cerrato RA. Freiberg’s disease. Foot Ankle Clin. 2011 Dec;16(4):647-58. [Link]
