title: Pinning across the metatarsophalangeal joint for hammertoe correction: where are we aiming and what is the damage to the metatarsal articular surface?
abstract: Kirschner wire (K-wire) fixation across the metatarsophalangeal joint (MTPJ) is commonly used in hammertoe repair surgery. The purpose of the present study was twofold: (1) to determine where the K-wire penetrates the metatarsal articular surface to achieve a rectus digit; and (2) to quantify the percentage of cartilage disruption to better understand the consequences of K-wire transfixation of the MTPJ. Arthrodesis was conducted on the second, third, and fourth proximal interphalangeal joints of 10 below-the-knee cadaver specimens, using a 1.6-mm K-wire. Digital alignment was confirmed with simulated weightbearing intraoperatively and radiographically. The K-wire was removed, and the MTPJ was dissected until the metatarsal head was fully exposed. The penetration point was plotted on a quadrant system with deviation noted from the epicenter. Center was defined as the point equidistant from the medial-to-lateral and superior-to-inferior edges on the distal surface of the metatarsal head, excluding the plantar condyles. Statistically significantly deviations were found in the K-wire placement from the center (35.9% ± 17.5%, p < .001), medial-to-lateral width (22.2% ± 19.2%, p < .001), and dorsal-to-plantar height (15.8% ± 25.0%, p = .002). Relative to the center, the K-wire was superior in 22 (79%), inferior in 6 (21%), medial in 22 (79%), and lateral in 6 (21%) of the cadaveric MTPJs. The mean percentage of disruption of the articular cartilage was 1.8% ± .4% and was similar for the second, third, and fourth MTPJs (p = .13) and for the left and right feet (p = .75). This information could be used to guide surgeons when they transfixate the MTPJ during hammertoe correction and might contribute to preservation of the articular cartilage.
authors.affiliation: Fellow, Department of Foot and Ankle Reconstruction, Coordinated Health, Bethlehem, PA.
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Galli
authors.affiliation: Fellowship Director, Department of Foot and Ankle Reconstruction, Coordinated Health, Bethlehem, PA. Electronic address: drsbrigido@mac.com.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Brigido
authors.affiliation: Research Associate, Coordinated Health, Bethlehem, PA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Protzman
mesh_terms: D001174:Arthrodesis / Q000009:adverse effects / Q000295:instrumentation; D001864:Bone Wires / Q000009:adverse effects; D002102:Cadaver; D002358:Cartilage, Articular / Q000293:injuries*; D005260:Female; D037801:Hammer Toe Syndrome / Q000601:surgery*; D006801:Humans; D008297:Male; D008683:Metatarsophalangeal Joint / Q000601:surgery*
keywords: articular cartilage; cadaver; complication; pin fixation; splintage; toe surgery