Talonavicular Dislocations: A Bad Actor Made Worse Without Sufficient Fixation

Abstract

Category: Trauma; Midfoot/Forefoot Introduction/Purpose: The talonavicular joint (TNJ) is critical to midfoot architecture, and traumatic disruptions of this joint threaten the midfoot arch. We sought to better elucidate injuries to the TNJ and understand if transient methods of stabilization after TN dislocations (TNDs), such as closed/open reduction with or without percutaneous pinning resulted in different radiographic and clinical outcomes when compared to more permanent methods such as bridge plating or primary arthrodesis of the TNJ. Methods: We retrospectively identified skeletally mature patients from one tertiary level 1 trauma center treated for midfoot injuries between 2002-2022. Patients with isolated or concomitant TNDs were included. Demographics, treatment, radiographic outcomes, and patient reported outcomes (PROs) were recorded. Patients who underwent temporary fixation methods (closed/open reduction and trans-articular pinning with k-wire removal at 6-8 weeks) were compared to those with permanent fixation (bridge plating or primary arthrodesis). Primary outcome was reoperation, including fusions and amputations. Secondary outcomes were radiographic arch measurements (Meary’s angle [MA], calcaneal inclination angle [CIA]) and PROMIS measures of physical function, pain interference, and anxiety. Sixty-two patients and 66 feet were included (Table 1). Average follow up was 2 years. Results: TNDs manifested as both pure dislocations (18) and in conjunction with associated injuries: chopart dislocations (5), talar head/body fractures (23), navicular fractures (35), and subtalar dislocations (25). Twelve were a part of Hawkins IV talar neck fracture dislocations (18%). Forty-two patients were treated with temporary fixation (64%). Injuries treated with transient fixation had higher mean change in MA from immediately postop to final follow-up (-7.9° v -1.1°, p=0.006). They also exhibited significantly different MA and CIA values at final follow-up (7.8° v -1.4°; 17.3° v 21.3°, p< 0.03). Nearly two thirds required reoperation; 32% underwent fusion and 7% required amputation. Fixation method had no significant association with PROMIS scores, but those with temporary fixation methods trended toward lower final PF scores (34.9 v 41.1, p=0.11). Conclusion: TNDs are generally the result of high energy mechanisms, often occurring in combination with other significant mid/hindfoot injuries. Reduction and fixation method of these injuries should be carefully considered to avoid potential ramifications of loss of normal arch and midfoot sag.