Multisegmental Foot and Ankle Kinematics in Hallux Valgus Before and After Surgery

INTRODUCTION: Hallux valgus (HV) is a common first metatarsophalangeal (MTP1) joint deformity characterized by lateral deviation of the large toe, medial deviation of the first metatarsal, and hallux pronation [1,2]. Progressive subluxation of the MTP1 joint is common and results in attenuation of the medial soft tissues and contracture of the lateral soft tissues. The flexors and sesamoid complex of the great toe are laterally displaced, and this displacement further increases the valgus moment at the MTP1 joint. This worsens the deformity resulting in subluxation, articular incongruity, and arthritis. The consequent pathologic anatomy leads to biomechanical dysfunction and impairment [3]. The common etiology is constricting footwear but some authors suggest intrinsic factors for HV. Pathologies located more proximally such as hypermobility of the first metatarsocuneifrom joint, pes planus, hindfoot pronation, and Achilles tendon contracture have been postulated to play a role in the development of HV [1]. Given the numerous potential pathological elements in HV, authors have described a vast number of operative procedures to address the deformities. Surgical correction of HV most commonly involves structures such as the distal metatarsal, the proximal phalanx, and soft tissues around the MTP1 joint; and frequently consists of a combination of operative procedures. Alterations in plantar loading and gait kinematics in HV have been studied in the past [4-7] but literature on quantitative characterization of segmental foot motion is limited. Given its vital role in normal gait, it is important to understand how hallux function is impaired and how the rest of the foot and ankle is affected in patients with this disabling condition. Equally important is how surgical treatment affects these segments. This study aims to describe segmental foot and ankle kinematics before and after surgery in a population of patients with HV. The results may help clarify the kinematic segmental interaction of this condition.