SLR - March 2020 - Matthew J. Dougherty
Reference: Sanders R, Serrano R. Navicular Body Fractures-Surgical Treatment and Radiographic Results. J Orthop Trauma. 2020 Feb;34 Suppl 1:S38-S44.Scientific Literature Review
Reviewed By: Matthew J. Dougherty, DPM
Residency Program: Temple University Hospital – Philadelphia, PA
Podiatric Relevance: Navicular body fractures are generally associated with high-energy mechanisms and can be difficult to surgically repair. Historically, the Sangeorzan classification has been utilized for methodically classifying navicular body fractures. As seen in this study, certain fractures cannot be placed into a specific classification based on the radiographic appearance. Another classification system, developed by Schmid et al, has been found to more readily classify a larger number of navicular body fractures. By utilizing this classification system and the results of this study, which assessed the radiographic and functional outcomes of Schmid type fractures, podiatric surgeons will be able to enhance their surgical planning in regards to fixation technique based off the Schmid classification and also be able to adequately discuss with the patient the prognosis of their injury in order to better patient expectations.
Methods: A retrospective radiographic study was completed at a Level 1 trauma center. All radiographs including fractures were queried for surgically treated navicular fractures between January 1, 2006 and December 31, 2015. Exclusion criteria included fractures in patients referred from other institutions, stress fractures, Sangeorzan/Schmid type I fractures, and those lost to follow-up. A total of 39 operatively treated, displaced navicular fractures with at least three years of follow up were included. The Schmid classification was determined to be a suitable classification system due to the nature of the injuries. Radiographs were then evaluated for the three-year follow-up course to determine radiographic presence of nonunion, malunion, post-traumatic arthritis, and any secondary operations and if there were any correlations between Schmid classification and post-operative outcome.
Results: Radiographic evaluation determined there were 18 Schmid type II fractures and 21 Schmid type III fractures. Of the Type II fractures, 10 were treated with tension band plates and eight were treated with screws. Of the Type II fractures, 12/18 healed without complications. A total of three complications arose in the screw technique group with one case requiring a revision secondary to failure of fixation and two required a talo-navicular fusion. It was noted that there were no cases of avascular necrosis in the Schmid type II group. Schmid type III results were found to be uniformly poor. Only three Schmid type III fractures healed after the primary procedure without evidence of post-traumatic arthritis. In addition, four of the Schmid type III fractures required talo-navicular fusion and the remaining 14 demonstrated radiographic collapse, end-stage post-traumatic arthritis, and significant mid-foot deformity.
Conclusions: Overall, navicular body fractures are severe injuries with non-uniform outcomes. The amount of comminution of Schmid Type II fractures determines the extent of damage to the talo-navicular joint. The form of fixation this study found to be most secure was the tension band technique due to its ability to prevent lag screw loosening. Schmid type III fractures were found to have a very poor prognosis. Ultimately, these injuries generally result in some form of extensive surgical reconstruction including reconstruction of the medial column, lateral column or both.