Current And Emerging Insights On Hammertoe Correction
Given the risks and patient concerns associated with K-wire fixation, these authors discuss the use of emerging hammertoe implants, absorbable pins and cannulated screws, and share a couple of illuminating case studies.
Hammertoe correction is one of the most frequently performed procedures for foot and ankle surgeons. Hammertoe digital deformity is characterized by an extension deformity at the metatarsophalangeal joint (MPJ) and a flexion deformity at the proximal interphalangeal joint.1,2
Digital deformity typically is associated with pain in the forefoot, difficulty fitting shoes and an unacceptable cosmetic appearance for the affected patients.2,3 Forefoot pain is typically attributed to hyperkeratotic skin lesions, callosities or ulcerations about the MPJ, the proximal interphalangeal joint and distal interphalangeal joints as well as nail deformities secondary to the curling of the digits.4 Loss of purchase of the digit overloads the MPJ as well as the surrounding digits, ultimately changing the gait pattern. This often advances other forefoot etiologies.
Treatment options are often guided by the patient’s discomfort as well as the reducibility of the affected digit. Conservative management of a fixed hammertoe includes shoe gear modification with a high and wide toe box, toe sleeves, a foam cushioning device, orthotics or offloading pads such as a metatarsal bar. However, if conservative management fails to alleviate symptoms, then surgical correction is warranted.
Surgical approaches for hammertoe correction are based on the surgeon’s preferred approach. We prefer the transverse elliptical incision over the proximal interphalangeal joint. One would perform a DuVries condylectomy on the head of the proximal phalanx. Using a rongeur, remove the cartilage of the base of the middle phalanx. Following this, the surgeon would implant the hardware under standard protocol.
K-Wires: A Fading Gold Standard For Hammertoe Repair?
K-wires have been the gold standard for hammertoe digital repair. Kirschner originally introduced K-wires to orthopedics in 1909, utilizing surgical grade stainless steel for the fixation of fractures. Taylor was the first surgeon to introduce K-wires for fixation of hammertoe repairs in 1940.5 Today, the most commonly used sizes for K-wire fixation in the foot and ankle are 0.9 mm (0.035 inch) to 1.6 mm (0.062 inch). The introduction of K-wire fixation for hammertoe correction was initially popular to help prevent flail toe, which is the most common complication secondary to excessive bone resection.1
Although K-wires are simplistic to use as fixation, they carry inherent risks such as pin tract infections, migration and breakage.3 Zingas and colleagues noted a 2.5 percent failure rate when they utilized 1.1 mm (0.045 inch) K-wire for fixation of the lesser digit hammertoe deformity.6 Reese and co-workers reported a rate of pin tract infections of as much as 18 percent in digital arthrodesis procedures with K-wire fixation.7 In a study by Caterini and colleagues, the average incidence of nonunion following proximal interphalangeal joint arthrodesis and fixation via intramedullary K-wire was about 20 percent.8
The biggest concerns our patients have about externally protruding K-wires are the anxiety with the removal of the K-wire in the office as well as accidental “trauma” within their home.