Average depth of tarsometatarsal joint for trephine arthrodesis.

The trephine arthrodesis technique has been shown to be an effective method for various foot and ankle fusion procedures, with acceptable rates of fusion reported. The tarsometatarsal joints are an excellent example for this procedure because of the joint shape and soft tissue stability. The success of this procedure depends on many factors, but a large consideration is adequate joint resection. A cadaveric study to examine the joint depth of the Lisfranc complex was undertaken, allowing for improved understanding of the resection needed to maintain a stable plantar cortex while removing all apposing joint surfaces. A statistical analysis was then performed to determine the significance of the joint depth to available demographic data. A total of 51 limbs were evaluated for the depth of the first, second, and third metatarsal-cuneiform joints. The average joint depth for the first through third metatarsal-cuneiform joints was 32.3, 26.9, and 23.6 mm, respectively. The plantar cortex depth was less than 2 mm for the first through third metatarsal-cuneiform joints. The correlation between the length of the foot and the joint depth was statistically significant. Subgroups stratified by shoe size were analyzed for differences in joint size and were also statistically significant. A better understanding of the tarsometatarsal joint anatomy would benefit the trephine technique for Lisfranc arthrodesis.