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Treatment ● Advice on footwear ● Insole with metatarsal bar/pad ● Functional foot orthoses ● Steroid injection ● 0.5% Marcaine injection ● Surgical excision

2. FREIBERG’S INFRACTION First described by Freiberg in 1914 where he observed in six cases that the metatarsal head appeared crushed as if infraction had occurred (Fig.3).

to return to physical activity ● Surgery - the type of surgical intervention is determined by the stage of the condition. If the condition is diagnosed early enough, blood supply is restored by bone graft. In stage 4 and 5 various options are available, which may include a dorsal closed wedge osteotomy (Gauthier osteotomy), excision of the metatarsal head, and silastic double stem hinge joint

3. MARCH FRACTURE (metatarsal stress fractures) Stress fractures of the metatarsals are not uncommon. The condi- tion was first described as a complication among army recruits who had to march carrying heavy loads, hence the term March fracture.

Figure 3: X-ray showing Freiberg’s infraction (stage 5)

Clinical picture It is an uncommon condition that affects the head of the second metatarsal, usually in adolescent females. There is no general agreement whether the infraction is due to arterial insufficiency or trauma, but in all cases avascular necrosis of the epiphysis is pre- sent. It is usually unilateral. There are five stages in the develop- ment of the condition as shown in table 1.

The pain mainly occurs on tiptoeing and in high-heeled shoes. This is as a result of reduced dorsiflexion at the MTP joint and early arthrosis. The condition is self-limiting and is usually not sympto- matic in adult life.

Investigations ● Plain radiograph ● Isotope bone scan

Treatment ● Conservative - the main aim is to reduce the pain. Various phys- iotherapeutic modalities are utilised. In stage 4 and 5 localised steroid injection can provide substantial relief and allow the patient

Stage 1 2 3

4 5

Development Fissure fracture. Bone absorption.

Further absorption with sinking of the central portion.

Loose body separation.

Flattening, degeneration of the 2nd metatarso-phalangeal joint (MTP joint)

12 SportEX Table 1: The five stages in the development of Freiberg’s infraction

Clinical picture This stress fracture occurs as a result of excessive loading, either as a result of unaccustomed exercise or intensive physical activity. It is not uncommon in middle aged joggers who are particularly sus- ceptible to stress fractures of either the 2nd or 3rd metatarsal shaft. The pain occurs over the forefoot and will be aggravated by run- ning, dancing or any impact activity. Initially the pain may be bear- able but will gradually get worse with activity. The foot will be swollen over the area of the fracture and tends to be more painful on the dorsal aspect with focal tenderness.

Investigations ● Plain radiographs (Fig.4) - in the early stages of the stress frac- ture, radiographs may appear normal ● Isotope bone scan (Fig.5) is a very sensitive investigation and is recommended when the x-ray shows no obvious abnormality but where the history is strongly suggestive of the condition

Figure 4: Plain radiograph of a stress fracture to the 3rd metatarsal

Figure 5: Isotope bone scan of a stress fracture to the 3rd metatarsal

Treatment ● Weight bearing rest for between 4-6 weeks ● In severe cases Aircast walking boot ● Foot orthoses

4. SESAMOID INJURY In the foot there are two sesamoids (medial & lateral) under the big toe joint in 99.9% of the population. It is however, not unusual to find more than two sesamoids, sometimes four, under the hallux joint. Bipartite sesamoids are found in approximately 30% of the population. Sesamoids are necessary for stabilisation of the first metatarso-phalangeal joint.