Operative Approach to Adult Hallux Valgus Deformity

Principles and Techniques

Glenn G. Shi, MD; Joseph L. Whalen, MD, PhD; Norman S. Turner III, MD; Harold B. Kitaoka, MD

Disclosures

J Am Acad Orthop Surg. 2020;28(10):410-418. 

In This Article

Diagnosis and Clinical Evaluation

History

Patients often present to the physician when they become symptomatic, with pain commonly located over their medial eminence associated with footwear. Patients may describe symptoms of transfer metatarsalgia and hammertoe deformity with weight-bearing. In those patients presenting with recurrent deformity after previous surgical correction, an effort must be made to determine why the deformity had returned. Medical history of spasticity, neurologic injury, and inflammatory arthropathy can affect decision-making in patients with hallux valgus.

Clinical Examination

Clinical evaluation begins with a standing examination, looking specifically for evidence of flatfoot deformity, instability of the medial column, pronation of the hallux, and alignment of the lesser toes. The sitting examination focuses on the range of motion in the ankle and hindfoot and evidence of equinus contracture. Forefoot evaluation begins at the skin overlying the medial eminence and then location of tenderness, range of motion tenderness (arthritis of the first MTPJ), passive correctability to neutral alignment, and the coexistent hallux valgus interphalangeus component. The range of motion of the MTPJ should be measured with a goniometer, recording the dorsi- and plantarflexion of the proximal phalanx relative to the plantar foot.

Controversy exists in the ability of physicians to quantitate the degree of TMTJ motion, not only varus and valgus but also the sagittal plane motion. Because typical values of motion in the TMTJ have not been clearly presented in the literature, its clinical utility may be limited. One can compare the motion with the contralateral side to see whether there is gross discrepancy.

Hallux valgus deformities can be associated with lesser toe deformities or pain. This may include hammertoe, claw toe, plantar callosity, previous second toe amputation, and second metatarsalgia.[2] Patients may be symptomatic enough to undergo corrective lesser toe deformities during the hallux valgus correction. A neurovascular examination should be performed because abnormalities such as severe neuropathy (lack of protective sensation) or vasculopathy (poor pulses, capillary refill) may affect surgical decision-making. Multidisciplinary collaboration may be needed with appropriate consultation from neurology, vascular surgery, or rheumatology. A prominent bunion can also irritate the dorsomedial cutaneous nerve, producing numbness around the dorsomedial border of the great toe.

Imaging

Complete evaluation of patients with hallux valgus deformity requires weight-bearing AP and lateral foot radiography, which would also reveal evidence of osteoarthritis of the first MTPJ, hallux valgus interphalangeus, flatfoot, metatarsus adductus, and lesser toe deformities.

Measurements

The hallux valgus angle (HVA) is defined as the intersecting angle measured on the weight-bearing AP foot radiograph from longitudinal lines that bisect the proximal phalanx and first metatarsal (Figure 1A). The intermetatarsal angle (IMA) is the angular measurement of the intersection from the longitudinal lines that represent the longitudinal axes of the first and second metatarsals (Figure 1B).[3]

Figure 1.

Radiographs illustrating the measurements of (A) HVA, (B) IMA, and (C) DMAA. DMAA = distal metatarsal articular angle, HVA = hallux valgus angle, and IMA = intermetatarsal angle

There is some debate on the measurement, reliability, and importance of the DMAA (Figure 1C). It has been commonly accepted that DMAA measurements >10° are abnormal. The reliability of DMAA on the weight-bearing AP foot radiograph can be affected by pronation and rotational changes of the first metatarsal shaft.[4]

A change in the sesamoid position in relation to the metatarsal head occurs from medial displacement of the first metatarsal because the hallux valgus deformity progresses. The lateral sesamoid does not translate and remains stable. Therefore, lateral sesamoid position can be used as a static marker for surgeons to evaluate the degree of medial displacement of the metatarsal head.[5]

Although our understanding of the hallux valgus deformity is not yet complete, a classification system based on the angular measurements and general principles has been proposed (Table 1).

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