Hallux valgus, commonly known as a bunion, is a progressive deformity of the first metatarsophalangeal (MTP) joint characterized by lateral deviation of the hallux and medial deviation of the first metatarsal. This condition frequently results in pain, impaired function, and difficulty with footwear, prompting many patients to seek surgical intervention. Among the array of surgical options, the Chevron osteotomy has emerged as a reliable and effective procedure for the correction of mild to moderate hallux valgus, particularly in patients with a congruent joint and minimal degenerative changes.
Background and Indications
The Chevron osteotomy, also referred to as the distal metatarsal “V” osteotomy, was first introduced by Austin and Leventen in 1981. It is primarily indicated for patients presenting with mild to moderate hallux valgus, typically defined by an intermetatarsal angle (IMA) of less than 15 degrees and a hallux valgus angle (HVA) of less than 30 degrees. The procedure is not generally recommended for severe deformities, significant joint degeneration, or where there is marked instability of the first ray.
Ideal candidates are those who have failed conservative management—such as footwear modification, orthoses, and physical therapy—and continue to experience pain or functional limitations. The Chevron osteotomy is particularly valued for its predictable correction, relatively low complication rate, and preservation of joint motion.
Surgical Technique
Preoperative Planning
Accurate preoperative assessment is critical. Weight-bearing radiographs are used to evaluate the extent of the deformity and to measure the HVA and IMA. The integrity of the first MTP joint and the presence of any associated pathologies, such as sesamoid subluxation or degenerative changes, should also be assessed.
Operative Steps
- Incision and Exposure:
A dorsomedial incision is made over the first MTP joint, taking care to avoid injury to the dorsal cutaneous nerves. The joint capsule is incised, and the medial eminence is exposed. - Osteotomy:
The Chevron osteotomy is performed at the distal metatarsal metaphysis, approximately 1 cm proximal to the articular surface. The osteotomy is V-shaped, with the apex directed distally. The distal fragment is then shifted laterally, correcting the metatarsal alignment. - Fixation:
Once the desired correction is achieved, the osteotomy is stabilized using a screw or Kirschner wire. The medial eminence is resected as necessary, and the capsule is repaired. - Closure:
The wound is irrigated, hemostasis is achieved, and the incision is closed in layers.
Postoperative Care
Postoperative protocols vary but generally include protected weight-bearing in a surgical shoe for 4–6 weeks, followed by gradual return to normal footwear and activities. Early mobilization of the MTP joint is encouraged to prevent stiffness.
Outcomes and Efficacy
Numerous studies have demonstrated the Chevron osteotomy’s efficacy in correcting mild to moderate hallux valgus deformities. Most patients report significant pain relief, improved function, and high satisfaction rates. Radiographic outcomes typically show substantial reduction in both HVA and IMA, with maintenance of correction over time.
Complication rates are low but can include delayed union, malunion, avascular necrosis of the metatarsal head, and recurrence of the deformity. Meticulous surgical technique and appropriate patient selection are critical to minimizing these risks.
Advantages
- Joint Preservation: Unlike more proximal osteotomies or arthrodesis procedures, the Chevron osteotomy preserves the first MTP joint, maintaining normal biomechanics and range of motion.
- Predictable Correction: The procedure offers reliable realignment for mild to moderate deformities.
- Low Morbidity: The minimally invasive approach and stable fixation enable early mobilization and a relatively quick recovery.
Limitations and Considerations
- Not Suitable for Severe Deformities: The Chevron osteotomy is less effective for severe hallux valgus, high IMA, or significant joint degeneration.
- Technical Precision Required: Accurate execution of the osteotomy and fixation is essential to avoid complications such as undercorrection, overcorrection, or joint stiffness.
- Recurrence: As with all bunion surgeries, recurrence can occur, particularly if underlying biomechanical factors are not addressed.
Comparison to Other Procedures
In comparison to other distal metatarsal osteotomies, such as the Scarf or Mitchell procedures, the Chevron osteotomy is technically simpler and associated with fewer complications. However, for larger deformities or in cases requiring greater correction, proximal osteotomies or more complex procedures may be indicated.
The Chevron osteotomy remains a mainstay in the surgical management of mild to moderate hallux valgus. Its joint-preserving nature, predictable results, and low complication profile make it a preferred choice for many podiatrists and foot surgeons. Careful patient selection, thorough preoperative planning, and meticulous surgical technique are essential to achieving optimal outcomes. As surgical techniques and fixation methods continue to evolve, the Chevron osteotomy is likely to retain its important role in the treatment of bunion deformities.
