Simultaneous Intraoperative Measurement of Cadaver Ankle and Subtalar Joint Compression During Arthrodesis With Intramedullary Nail, Screws, and Tibiotalocalcaneal Plate.

BACKGROUND: Suboptimal tibiotalocalcaneal arthrodesis (TTCA) fusion rates may result from inadequate compression that increases motion and interferes with bony bridging. The aim of this study was to evaluate compressive forces at the ankle and subtalar joints with 3 contemporary TTCA constructs.

METHODS: Thirty fresh-frozen cadaveric lower extremity specimens were divided into 3 groups of 10 each: 3 partially threaded cannulated screws, hindfoot nail, and lateral plate. Specimens were mounted to a testing apparatus, and compression was independently measured at the tibiotalar and talocalcaneal interfaces. Statistical analysis included paired Student t tests, analysis of variance, and Tukey post hoc tests.

RESULTS: Mean forces at the ankle joint for the screws, nail, and plate constructs were 331 ± 86, 479 ± 137, and 548 ± 199 N, respectively, with plates providing significantly more compression than screws ( P < .01). Similarly, subtalar compressive forces demonstrated 319 ± 105 N in the screws group, 466 ± 125 N, in the nail group, and 513 ± 181 N in the plate group, with plate compression greater than that achieved with screws ( P < .01). No differences were identified in compression between ankle and subtalar joints within specimens in any group.

CONCLUSIONS: Lateral TTCA plates provided increased compressive forces at the ankle and subtalar joint compared with screws-only constructs. Hindfoot nails did not demonstrate significant differences in either of these parameters compared with plates or screws in this study.

CLINICAL RELEVANCE: Hindfoot nail and lateral plate options should be strongly considered when aiming to maximize compression in patients undergoing TTCA.