Review Question - QID 211473

This patient has a hallux valgus deformity. Due to its attachment to the lateral aspect of the proximal phalanx and the fibular sesmoid, the adductor hallucis displaces laterally and becomes a primary deforming force in hallux valgus.

The pathoanatomical changes observed with hallux valgus deformity of the great toe occurs in a predictable pattern. First, valgus deviation of the phalanx promotes varus positioning of the metatarsal which displaces the metatarsal head medially leaving the sesamoid complex laterally translated relative to the metatarsal head. The sesamoids remain within the respective head of the flexor hallucis brevis tendon attached to the base of the proximal phalanx. With time, the medial MTP joint capsule becomes attenuated while the lateral capsule becomes contracted. The adductor tendon is allowed to become a primary deforming force as its attachment to the lateral aspect of proximal phalanx and fibular sesmoid accentuates this deformity. There is further contribution of the deformity due to the lateral deviation of the extensor hallucis tendons. The plantar and lateral migration of the abductor hallucis leads to plantarflexion and pronation of the phalanx. Due to its attachment to the base of the proximal phalanx, the adductor hallucis is often part of the first web space release along with the sesamoid suspensory ligament and the first MTP capsule.

Perera et al. review first ray static and dynamic stability. They report on the incomplete and nonlinear associations of several inherent or acquired biomechanical abnormalities with hallux valgus. They conclude that hallux valgus management should be tailored to the individual.

Devos et al. review the radiographic and clinical assessments used to identify the involved factors of hallux valgus. They report on the variables that best determine the recommended approach to correct the deformity. They note however, that following surgery, iatrogenic hallux varus may ensue as a complication. This should be managed similarly to acquired hallux varus.

Figure A demonstrates an incongruent MTP joint with lateral translation of the sesmoids with severe hallux valgus

Incorrect Answers:
Answer 1: The abductor hallucis is an intrinsic muscle of the foot that contributes to abduction and flexion of the great toe. This tendon moves laterally with gradual deformity of the foot and contributes to plantarflexion and pronation of the phalanx with this deformity
Answer: 3: The flexor hallucis brevis is displaced laterally with this deformity and has the sesmoids remined within its tendon. Its more plantar orientation contributes less to the valgus deformity than the adductor hallucis
Answer 4: The laterally based structures (adductor hallucis and contracted lateral capsule) are the primary contributors to the valgus deformity with hallux valgus
Answer 5: Flexor hallucis longus is not intimately associated with the sesmoid complex and is not a primary deforming force with hallux valgus deformity