Review Question - QID 278

This patient has a moderate hallux valgus deformity as shown by the intermetatarsal angle of 15 degrees shown in Figure B, and the hallux valgus angle of 40 degrees shown in Figure C. A Scarf osteotomy is the only procedure of the available options in isolation appropriate for this amount of deformity.

If there is an incongruent joint, a soft tissue rebalancing is appropriate to make the joint congruent. With a congruent MTP joint and a DMAA of greater than 10 degrees, the distal articular surface needs to be realigned to create an appropriate correction. Moreover, this patient's IMA is >13 degrees suggesting moderate disease necessitating the need for a proximal metatarsal osteotomy. A Scarf osteotomy adequately addresses this.

The review article by Jones et al describes multiple methods of proximal osteotomies including crescentic, chevron, and oblique osteotomies. Overcorrection of IMA can lead to hallux varus and dorsiflexion at osteotomy can lead to transfer metatarsalgia. Double osteotomies can also be utilized for moderate deformities with Jones et al describing 92% satisfaction with a combined Akin and scarf osteotomy (Illustration A).

The Level 5 review article by Robinson et al discussing management of hallux valgus. They review several surgeries and note that the distal chevron is most often used in a non-congruent deformity with a normal DMAA. A complication with the Chevron and other distal osteotomies is the development of AVN of the first metatarsal head with an estimated incidence of up to 20% reported in the literature.

Illustration B demonstrates a hallux valgus deformity with a congruent MTP joint, as is also the case for the patient in this question. A distal soft-tissue release, including a release of the lateral structures, would be an appropriate procedure combined with a proximal metatarsal osteotomy if the MTP joint was incongruent.

Incorrect Answers:
Answer 1: An Akin osteotomy is a proximal phalanx osteotomy. Its indications include hallux valgus interphalangeus, a congruent joint with DMAA <10°, or is used as a secondary procedure if a primary procedure (e.g., chevron or distal soft-tissue procedure)did not provide sufficient correction due to a large DMAA or HVI
Answer 2: Distal soft tissue release attempts to correct an incongruent MTP joint Its indications include a HVA less than 25 degrees, IMA deformity less than 15 degrees and is rarely appropriate in isolation
Answer 3: MTP arthrodesis is indicated with hallux valgus in cerebral palsy, Down's syndrome, rheumatoid arthritis, gout, severe DJD, and Ehler-Danlos
Answer 4: A medial eminence resection and exostectomy (Silver)is a simple exostectomy/bunionectomy procedure involving resection of the medial eminence and is indicated in mild disease