Foot and Ankle cases 42

A 31-year-old female presents to your office with increasing pain over the posterior medial ankle and stiffness in the great toe. She works as a professional ballet dancer and complains of increasing pain in the “demi pointe” position. On physical examination, the patient is noted to have decreased motion through the first MTP

joint and triggering of the first MTP joint with passive dorsiflexion. Dorsiflexion of the first MTP joint is measured both with the ankle in maximal plantar flexion and in moderate dorsiflexion. A decrease in first MTP motion of 30 degrees is noted when the ankle is brought into dorsiflexion. An MRI of the ankle is obtained (Fig. 5–88).

 

 

 

Figure 5–88 Axial T2-weighted MRI showing increased fluid surrounding the FHL tendon (arrow), consistent with FHL tenosynovitis.

 

FHL tenosynovitis can occur at which anatomic location?

1. Posterior ankle

2. Sustentaculum tali

3. Plantar midfoot

4. Level of the sesamoids

5. All of the above

 

Discussion

The correct answer is (E). FHL tenosynovitis can occur in four different regions of the foot and ankle. On physical examination, it is important to examine each region to localize the pathology. The muscle belly and musculotendinous region can be palpated at the level of the ankle posterior and lateral to the posterior tibial tendon. FHL tenosynovitis can occur in the setting of posterior ankle impingement associated with a symptomatic os trigonum. Most commonly, FHL tenosynovitis

occurs as the tendon enters the fibroosseous canal, which can be palpated inferior to the sustentaculum tali. At the plantar midfoot, at the level of the navicular medial cuneiform articulation, the FHL can be palpated as it traverses the knot of Henry. Distally, FHL tenosynovitis can occur at the level of the sesamoids and the FHL can be palpated plantar to the first metatarsal head.

The patient is diagnosed with FHL tenosynovitis. You initiate conservative treatment with immobilization in a walking boot and physical therapy to focus on FHL stretching. The patient wants to know the success rates of conservative treatment.

True/False: Nonoperative treatment of FHL tenosynovitis is successful 80% of the time?

1. True

2. False

 

Discussion

The correct answer is (B). The success of nonoperative treatment is low. Failure rates of nonoperative treatment have been reported at 40% to 100%. However, most authors recommend a 6-month trial of nonoperative treatment including rest, immobilization, NSAIDs, and stretching.

The patient fails nonoperative treatment and requires excision of a symptomatic os trigonum and release of the FHL through a posteromedial approach.

What is the intramuscular interval typically used for this approach?

1. Flexor digitorum longus and flexor hallucis longus

2. Flexor hallucis longus and peroneus brevis

3. Tibialis posterior and flexor hallucis longus

4. Peroneus longus and peroneus brevis

 

Discussion

The correct answer is (A). The posterior medial approach to the ankle is centered over the neurovascular bundle posterior to the medial malleolus. After incising the skin, the fascia and laciniate ligament are split to expose the neurovascular bundle. The bundle is most often retracted posteriorly, protecting the medial calcaneal branch of the tibial nerve. Next the deep aspect of the sheath is released to expose the FHL tendon. At this point, a tenosynovectomy can be performed. The FHL can be retracted posteriorly to gain access to the Os trigonum. This exposure can be

extended as needed plantar to the sustentaculum tali to release the fibroosseous tunnel.

 

Objectives: Did you learn...?

 

 

 

Describe the physical examination findings for FHL tenosynovitis? Identify nonoperative approach to management of FHL tenosynovitis? Describe the posterior medial approach to the ankle?