Cadaveric analysis of articular involvement following placement of tibiotalocalcaneal retrograde nail.

Objective: Previous studies have analyzed Tibiotalocalcaneal (TTC) nail placement and proximity to neurovascular structures. However, there is a paucity of literature regarding the bony/articular involvement following nail placement. The objective of this study is to analyze calcaneus, talus, and tibia bone structures and articular involvement of the tibiotalar and subtalar joints following TTC nail placement.

Methods: Ten fresh-frozen cadaver legs were utilized without previous injuries or surgeries. Prior to nail placement, the tibiotalar and subtalar joints were arthroscopically evaluated for any pre-existing defects or bony abnormalities. The starting point for a TTC nail was established using fluoroscopic guidance with anteroposterior, lateral, and calcaneal views. Following nail placement, each specimen was dissected to analyze for any compromise of the plantar neurovascular bundles and surrounding bone structures. Measurements of nail involvement of the tibiotalar and subtalar joints were recorded.

Results: An arthroscopic evaluation of the specimen before nail insertion confirmed no cartilage abnormalities in any specimen. After nail insertion, four of ten (40%) of the specimens had a partial breach of the medial wall of the calcaneus with no associated fracture. There was no damage to the neurovascular bundles. On average, the subtalar joint had 4.7% of the total cross-sectional area involved in the posterior subtalar facet. In the tibiotalar joint, there was no additional involvement of the articular surface on the talar dome or tibial plafond outside the nail diameter. There was no breach of the walls of the talar dome or tibial plafond.

Conclusions: There was no significant damage to the surrounding neurovascular structures or soft tissues. The posterior subtalar facet had minimal involvement after a TTC nail placement. A more lateral and anterior entry point may avoid a medial wall breach and avoid the posterior subtalar facet.