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

Authors' Preferred Approach and Technique

No single operation can be universally applied to all patients with hallux valgus. It first must be determined whether the patient has significant pain, impairment, understanding of the proposed operation, appropriate expectations, and ability to comply with postoperative care. Once it is determined whether a patient is a candidate for operative management, the choice is dependent on the condition of the MTPJ, degree of the deformity, associated conditions, and other patient factors. For patients with severe MTPJ arthritis or failed hallux valgus operations, arthrodesis is applicable.

In symptomatic patients without arthritis, with mild deformities without a rotational component, we recommend distal chevron osteotomy transfixed with a single screw or 2-mm absorbable pin, with the release of only the lateral capsular tissue and not adductor hallucis. For elderly patients with very low demands with symptoms primarily because of a prominent medial eminence who cannot tolerate the recovery and weight-bearing limitations of an osteotomy, a simple bunionectomy is applicable.

For distal chevron osteotomy, a standard medial longitudinal incision is made around the MTPJ. Subcutaneous dissection is performed carefully to protect the dorsomedial cutaneous nerve branch. Longitudinal or inverted L-shaped capsulotomy is performed, developing a thick periosteal flap and exposing the joint. Medial eminence resection is performed 1 mm medial to the sulcus in line with the medial border of the metatarsal shaft. With distraction of the joint, the lateral capsule may be released under direct visualization. A Kirschner wire is placed at the center of the metatarsal head to guide the microsagittal saw, preventing unintended elevation or depression of the metatarsal head and converging or diverging osteotomy cuts. The osteotomy angle is cut between 55° and 60° (Figure 3). Stripping of the plantar and lateral periosteum is avoided to limit the risk of osteonecrosis and nonunion. With traction of the great toe, translation of the distal fragment can be performed from 33% to 50% of the width of the metatarsal head. Controlled gentle axial compression along the hallux allows for mild impaction of the osteotomy. The osteotomy should be stable with both valgus and rotational positions of the improved toe. The osteotomy is temporarily pinned in place with a guide wire for a 2.0-mm cannulated compression screw, and then drilling and placement of the screw are performed. A 2.0 mm absorbable may be used instead, oriented from proximal to distal. The remaining metatarsal neck fragment is removed in plane parallel with the medial border of the foot. A small portion of the redundant capsular tissue can be excised with a tight medial capsular closure with 2 to 0 absorbable suture. We do not rely on aggressive lateral soft-tissue release or excessively tight medial capsular closure to compensate for an incomplete bony correction. Compressive forefoot soft dressing is applied. Patients are instructed to bear weight through the heel in postsurgical shoes, as tolerated, for 6 weeks. In some instances, a Robert Jones compressive dressing with splint is applied initially, followed by a short leg cast for 3 weeks.

Figure 3.

Illustration showing the medial approach to distal chevron osteotomy.

Moderate deformities may be addressed with either proximal osteotomy such as scarf although distal ostetotomies may also be applied successfully. A lateral soft-tissue release may be performed. In some instances, it is helpful to judge the adequacy of the correction intraoperatively with capsular closure and removal of the tourniquet to see whether the great toe has been rebalanced and derotated. This may be performed by visual inspection with simulated weight-bearing and fluoroscopy.

The scarf osteotomy is performed through a medial incision around the forefoot over the MTPJ and longitudinal capsulotomy. A proximal extension of the capsulotomy is performed to expose the midshaft of the first metatarsal (Figure 4). The distal fragment is translated laterally. In some instances, the osteotomy is translated laterally and rotated medially to achieve correction. A two-screw fixation technique is used to stabilize the osteotomy. Our postoperative protocol is similar to that after distal osteotomies.

Figure 4.

Illustration showing the medial approach to scarf osteotomy.

In patients with first TMTJ arthritis, a modified Lapidus procedure can be used to address both the hallux valgus correction and the TMTJ arthritis. We do not primarily use the modified Lapidus procedure as the first TMTJ hypermobility, which is difficult to define. A dorsal incision is made over the first TMTJ. The extensor hallucis longus tendon is retracted laterally, and the joint capsule is then incised. With joint distraction by pin distractors, the joint is prepared using a combination of microsagittal saw, curettes, and rongeurs, and the subchondral sclerotic bone is punctured with a 2.5-mm drill. The metatarsal head is reduced over the sesamoid complex because the microsagittal saw is passed through the TMTJ to remove any imperfections in joint preparation. The TMTJ is pinned provisionally, and screw and plate fixation is used. A distal lateral soft-tissue release may be needed through a smaller but separate incision. After a modified Lapidus procedure, we routinely cast the patient for 4 to 6 weeks before full weight-bearing.

Congruent hallux valgus deformities with a dysplastic metatarsal head may require a more complex double metatarsal osteotomy technique to correct the DMAA. A closing wedge biplanar distal chevron osteotomy is recommended for most patients.

After correction of the hallux valgus, if there is significant residual interphalangeus deformity, an Akin osteotomy may be performed. An incision is typically extended to the midshaft of the proximal phalanx. A medial closing wedge osteotomy is performed using a microsagittal saw at the base of the phalanx, and a cannulated 2.0-mm compression screw is used to transfix the osteotomy.

In severe deformities with arthritic changes, revision hallux valgus deformity, and selected neurologic conditions, or inflammatory arthropathies, the first MTPJ arthrodesis should be considered. A medial or dorsal longitudinal incision is made over the MTPJ, and care is take to avoid trauma to the extensor hallucis longus tendon and dorsomedial cutaneous nerve. Gentle pressure on the conical reamers is a reliable method joint surface preparation. A flat surface platform can be used to simulate a weight-bearing foot to guide hallux valgus correction to 5° to 10° valgus, neutral rotation, and 5° to 10° dorsiflexion relative to the plantar foot. Either two cross screws or a cannulated compression screw in addition to a dorsal MTPJ plate fixation may be used for fixation. Forefoot dressings are applied, and patients are instructed to bear weight in a postsurgical shoe for 6 weeks before transitioning to a tennis shoe. In some instances, a Robert Jones dressing is applied followed by a cast.

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