Foot and Ankle cases 4

A 53-year-old man presents to your office 2 months after a motor vehicle accident. He reports that he had to slam on the break prior to a collision and noted the immediate onset of pain in his left foot. He was taken by ambulance to an emergency room, where he underwent a reduction of a dislocated great toe. He reports that he has been wearing a walking boot since the time of the injury. A photograph and x-ray of his foot are shown (Figs. 5–7 and 5–8). On examination, you are able to passively push his toes into proper alignment.

 

 

 

Figure 5–7 Photograph of the left foot with patient standing.

 

 

 

Figure 5–8 Standing AP radiograph of the left foot.

 

What is your diagnosis?

1. Ligamentous Lisfranc injury

2. Hallux varus

3. Hallux valgus

4. Turf toe

 

Discussion

The correct answer is (B). The patient likely sustained a varus-directed dislocation at the first metatarsophalangeal (MTP) joint. This was presumably closed-reduced,

but a hallux varus deformity has persisted. There is no widening between the medial cuneiform and second metatarsal base to suggest Lisfranc injury. The photograph and x-ray show hallux varus, not hallux valgus. And while a turf toe that differentially ruptured the lateral aspect of the plantar plate of the hallux could result in hallux varus, the better answer to this question is hallux varus.

Which of the following structures around the first MTP joint are restraints preventing hallux varus?

1. Lateral capsule, lateral ligaments, adductor hallucis, lateral aspect of the flexor hallucis brevis, fibular sesamoid

2. Lateral capsule, lateral ligaments, abductor hallucis, lateral aspect of the flexor hallucis brevis, fibular sesamoid

3. Lateral capsule, lateral ligaments, adductor hallucis, lateral aspect of the flexor hallucis brevis, tibial sesamoid

4. Lateral capsule, lateral ligaments, abductor hallucis, lateral aspect of the flexor hallucis brevis, tibial sesamoid

Discussion

The correct answer is (A). The first MTP joint is balanced by both bony and soft tissue stabilizers. The soft tissue stabilizers on the lateral aspect of the joint prevent the toe from drifting into a hallux varus position.

The most common cause of hallux varus is:

1. Congenital

2. Traumatic

3. Shoe-wear related

4. Over-correction during hallux valgus surgery

 

Discussion

The correct answer is (D). Hallux varus has been reported to occur between 2% and 15% of the time after hallux valgus surgery. This can result from a number of technical causes, including over-correction with a metatarsal osteotomy or fusion, excessive resection of the medial first metatarsal head, excessive tightening of the medial capsule, and excessive lateral soft tissue release. Postoperative hallux varus has been described with the true McBride procedure, in which the fibular sesamoid is excised.

After you meet this patient, your initial management should include all of the following except:

1. Closed reduction and percutaneous pinning of the hallux

2. Shoe modifications with the use of wider shoes and/or shoe stretching

3. Strapping or taping of the hallux into a neutral position

4. Counseling on the importance of avoiding narrow toe-box shoes

 

Discussion

The correct answer is (A). This patient presents to you 2 months after his injury. For hallux varus, the initial treatment is most often nonsurgical and should involve patient counseling and shoe modifications to avoid shoes that rub against the hallux. Sometimes taping or strapping of the hallux into a neutral position can manage symptoms.

This patient undergoes a period of attempted taping and shoe modifications, yet finds that he has persistent pain at his hallux MTP joint and also from his toe rubbing against his shoes. You decide to proceed with operative reconstruction.

What is the most appropriate procedure for this patient?

1. First MTP joint arthrodesis

2. Proximal metatarsal osteotomy

3. Extensor tendon transfer

4. Reverse distal Chevron osteotomy

 

Discussion

The correct answer is (C). Extensor tendon transfer, either with extensor hallucis longus (EHL) or extensor hallucis brevis (EHB), has been shown to effectively correct a nonarthritic flexible hallux varus deformity. If using the EHL—either the entire EHL or a split portion of the EHL—the tendon is released distally and then passed deep to the transverse metatarsal ligament and attached to the hallux proximal phalanx to correct the deformity. If using EHB, the attachment distally is maintained and the proximal portion of the tendon is passed deep to the transverse metatarsal ligament and then attached to the first metatarsal head to hold the deformity corrected. These procedures are often coupled with a medial soft tissue release.

 

Objectives: Did you learn...?

 

Identify structures that contribute to maintenance of alignment of the hallux MTP

joint?

 

Pinpoint causes of hallux varus?

 

Describe various treatment options for hallux varus?