Foot and Ankle cases 24

A 50-year-old male presents with 6 months of atraumatic forefoot pain. He has noticed the gradual onset of pain that is worse with running and prolonged weight bearing. There has been no trauma, and he has not recently changed his exercise regimen. He denies numbness, tingling, or burning. On physical examination, there is mild hammering of the second toe. He is focally tender at the second

metatarsophalangeal joint, which can be translated dorsally (positive “drawer” test). There is no web space tenderness. Weight-bearing radiographs of the foot were obtained (Fig. 5–51).

 

 

 

Figure 5–51 A–C: Weight-bearing radiographs of the foot.

 

What is the most likely diagnosis?

1. Morton’s neuroma

2. Metatarsal stress fracture

3. Second metatarsophalangeal synovitis and instability

4. Freiberg’s infraction

 

Discussion

The correct answer is (C). The history, physical examination, and radiographs are most consistent with second metatarsophalangeal synovitis and instability. The second metatarsophalangeal joint can become inflamed, injured, and unstable, which can lead to pain and sometimes deformity. Most often pain in this joint is the result of thinning or a tear of the plantar plate, which essentially is a thickening of the plantar joint capsule. Due to the instability, the joint does not track properly and becomes inflamed and painful. This condition is often associated with a long second metatarsal, which is visible on the radiographs. He is nontender in the web space and

denies any burning sensation, making Morton’s neuroma less likely. While a gradual onset may be seen in metatarsal stress fractures, they typically occur with a change in exercise frequency, duration, or intensity. The second metatarsal head is characteristically the site of Freiberg’s infraction, but there is no evidence of an irregular bony surface, sclerosis, or flattening of the metatarsal head.

Initial treatment might include all of the following treatment except:

1. Metatarsal pads or a custom orthotic

2. Taping or a “Budin” splint

3. A short walking boot

4. A corticosteroid injection

 

Discussion

The correct answer is (D). All of the above are appropriate initial treatments except for injection. This is the most invasive choice and is also associated with joint dislocation due to further attenuation and weakening of the plantar plate from the corticosteroid.

Despite these treatments, the patient remains symptomatic 6 months later and reports unchanged pain that interferes with activities of daily living. He requests surgery.

Of the following, which is the most appropriate surgical intervention?

1. Shortening metatarsal osteotomy

2. Extensor tendon transfer

3. Syndactylization of the second and third toes

4. Partial second metatarsal head resection

 

Discussion

The correct answer is (A). The long second metatarsal is felt to contribute to the attenuation of the plantar plate. As such, most surgeons use a shortening osteotomy, with or without a plantar plate repair, if surgery is indicated.

 

Objectives: Did you learn...?

 

Differentially diagnose second metatarsophalangeal joint pain?

 

 

Identify initial treatment options for second metatarsophalangeal joint synovitis? Describe the relationship between a long second metatarsal and second

metatarsophalangeal joint synovitis and instability?