Foot and Ankle cases 13

A 45-year-old man presents to your office with pain and stiffness in his big toe. He denies any history of trauma. He has noticed increased pain with exercise. His pain is primarily over the dorsal aspect of first metatarsophalangeal (MTP) joint. On physical examination, there is a negative MTP joint grind test and dorsiflexion is limited to 30 degrees. He complains of pain when jogging. Weight-bearing AP and lateral radiographs were obtained (Fig. 5–25A and B).

 

 

Figure 5–25 A, B: AP and lateral radiographs demonstrating degenerative changes in the first MTP joint with a dorsal osteophyte and <50% loss of joint space.

 

Which of the following orthoses may be effective in reducing symptoms?

1. Orthotic with Morton’s extension

2. Hinged AFO

3. UCBL

4. Arizona brace

 

Discussion

The correct answer is (A). A Morton’s extension provides added stiffness under the

first MTP joint to limit dorsiflexion through the first MTP joint. Alternative forms of shoe modification include a carbon fiber insert, stiff soled shoe, and toe box stretching. A hinged AFO and Arizona brace would stabilize the ankle and would not address the pain at the hallux. A UCBL (University California Biomechanics Laboratory) orthosis is used to stabilize flexible deformities such as flexible pes planus or flexible metatarsus adductus/abductus.

After failing treatment with a Morton’s extension orthosis and shoe wear modification, the patient has elected to proceed with surgery.

What would be the most appropriate surgical treatment option at this point?

1. Cheilectomy

2. Lapidus procedure

3. Clayton–Hoffman procedure

4. Keller procedure

5. First MTP arthrodesis

 

Discussion

The correct answer is (A). A cheilectomy is a good treatment option for younger patients wanting to preserve motion of first MTP joint. It is best for patients with “bump” pain and no pain in the mid arch of motion (grind test). It has been shown to be effective in grade I–II first MTP joint arthritis and can be combined with a Moberg (proximal phalanx) osteotomy to treat grade III disease. A Lapidus procedure is an arthrodesis of the first tarsometatarsal joint. A Clayton–Hoffman procedure combines a first MTP fusion with resection of the lesser metatarsal heads and is typically used to treat severe forefoot deformities associated with inflammatory arthritis. A Keller procedure is a resection arthroplasty of the first MTP joint and is best used in very low-demand patients with severe hallux rigidus. The Keller procedure often leads to a “cock-up” toe deformity and poor push off strength. Arthrodesis can be used to treat more severe or global forms of first MTP arthritis, such as grade III and IV diseases.

After performing a cheilectomy, range of motion is limited to 20 degrees of dorsiflexion. What is the best option for increasing dorsiflexion in this setting?

1. Keller procedure

2. Akin osteotomy

3. Release of the flexor hallucis brevis

4. Moberg osteotomy

 

Discussion

The correct answer is (D). The Moberg, or dorsiflexion osteotomy of the proximal phalanx, can be combined with a cheilectomy procedure to increase effective dorsiflexion through the first MTP joint. It can be used if the cheilectomy does not achieve 30 to 40 degrees of dorsiflexion or if the patient is a runner. Runners require >60 degrees of dorsiflexion. A Keller procedure is poorly tolerated in young, active patients hoping to preserve push off strength. An Akin osteotomy is a varus producing proximal phalanx osteotomy used to treat hallux valgus interphalangeus. Release of the flexor hallucis brevis will result in unopposed pull from the extensor hallucis brevis and flexor hallucis longus, resulting in a claw toe deformity.

Branches from which sensory nerve are at risk from the dorsomedial approach to the great toe?

1. Medial plantar

2. Superficial peroneal

3. Tibial

4. Saphenous

5. Deep peroneal

 

Discussion

The correct answer is (B). The superficial peroneal nerve branches into the medial dorsal cutaneous and the intermediate dorsal cutaneous nerves, providing sensation to the dorsal foot. The first web space is innervated by the deep peroneal nerve. The medial plantar nerve is a branch off of the tibial nerve and provides sensation to the plantar medial foot. The saphenous nerve is the largest cutaneous nerve from the femoral nerve and provides sensation to the medial foot up to the level of the first MTP joint.

 

Objectives: Did you learn...?

 

 

Describe approach to nonoperative management of hallux rigidus? Identify the indications for cheilectomy?

 

Identify when it is appropriate to consider the addition of a Moberg osteotomy?