Essential Insights On Treating Freiberg's Infraction

Author(s): 
By Justin Franson, DPM, and Babak Baravarian, DPM

As practitioners of the foot and ankle, some conditions and their treatment options become second nature to us. For example, it seems we are fairly comfortable with the treatment options associated with a degenerated first metatarsophalangeal joint. However, what does one do with the patient who has pain at the ball of the foot when X-rays reveal flattening of the second metatarsal head and degenerative changes in the second metatarsophalangeal joint? The answer probably should be, “Well, it depends.” Freiberg’s disease can vary in severity and typically undergoes a progression over time. Accordingly, let us take a closer look at some of the findings and variables with this condition, and review the conservative and surgical treatment options. First described by Freiberg in a review of six cases in 1914, infraction of the metatarsal head is most common in young females. The onset of the condition often occurs in the early to later stages of puberty. Although the etiology is not known for sure, the prevailing thinking is there is a vascular disruption at the epiphyseal plate that is likely secondary to trauma. Repetitive stress can cause microfractures at the junction of the epiphysis and metaphysis. The disease process can be gradual over time as it responds to the repetitive trauma. The onset of this process of aseptic necrosis or osteochondrosis commonly occurs in this patient population while the epiphyseal plate is open. It is not uncommon for a patient to be relatively asymptomatic through this process only to have the condition reveal itself later in life in response to poor shoegear, high heels, increased activity, etc. There is a strong female predilection in Freiberg’s disease with females five times more likely to have the condition than men. An Overview Of Key Findings And Diagnostic Considerations As mentioned above, Freiberg’s disease most commonly affects adolescent girls, especially those involved in athletic activities. The patient typically complains of focal pain at the ball of the foot in the region of the second metatarsal head. The pain is exacerbated with activity and typically increases over time. It is not uncommon for a patient to be asymptomatic during the early stages and for symptoms to develop later in life as a result of the joint degeneration. Radiographic findings can show early osteopenia with subchondral fracture. (See “Infraction Or Infarction?” below) Subchondral sclerosis can develop over time. Flattening of the metatarsal head is a classic sign that one usually sees with this condition, especially later in the patient’s life. The fracture and fragmentation can lead to sclerosis and avascular necrosis of the fragments. Loose bodies can form over time, contributing to the joint degeneration and the symptoms. Authors have presented radiographic classification of this condition in the literature. Smillie’s classification (1967) seems to be quoted most often and is summarized as follows:1Stage 1: Subtle fracture line through the epiphysis. Stage 2: Central depression. Stage 3: Central depression leads to medial and lateral projections at the margins. Plantar hinge remains intact. Stage 4: Central portion frees from the intact plantar hinge, forming a loose body. Fractures of the medial and lateral projections. Stage 5: Flattening of the metatarsal head with secondary degenerative changes. In most cases, when one is considering surgery, it is a good idea first to obtain a MRI of the forefoot in order to check the surrounding quality of bone and the level of damage to the joint involving the avascular necrosis. The points to consider include: • the amount of cartilage damage; • the location of cartilage damage (dorsal versus the entire surface versus central damage); • the quality of the cartilage and bone surrounding the infarction region; and • the level of degeneration to the base of the associated phalynx. Infraction Or Infarction? Freiberg’s infraction was the term used to describe Freiberg’s disease. This indicated that there was a traumatic etiology involving epiphyseal fracture and fragmentation. This causes a secondary obstruction of local blood flow, leading to an infarction or avascular state of the metatarsal head. Both terms could be appropriate for describing this condition. The infraction may have caused the infarction.

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