Classifications in Brief: Sanders Classification of Intraarticular Fractures of the Calcaneus

Calcaneus fracture classification systems have evolved since Malgaine [10] first described them in 1843, before the advent of roentgenography. The French surgeon described two types of fracture mechanisms: an avulsion injury resulting from muscular pull and a crushing injury. In 1931, Böhler described the first comprehensive calcaneal fracture classification scheme with eight fracture patterns based on plain radiographs, proposing two major groups: intraarticular and extraarticular [1, 2]. In 1952, Essex-Lopresti [5] further distinguished intraarticular fracture patterns into two types (depending on the exit point of the secondary fracture line): “tongue type” and “joint depression” fractures. This classification scheme aided the surgeon in determining the treatment plan but had limited prognostic relevance. Subsequently, in 1975, Soeur and Remy [19] proposed a classification scheme based on the number of articular fragments and fracture displacement as determined on AP, lateral, and Harris axial heel views of the calcaneus. This classification was based on the extent of posterior facet articular involvement. Firstdegree fractures were nondisplaced shear-type fractures with widening of the joint surface. Second-degree fractures included a secondary fracture line, which produced at least three fragments. Third-degree fractures were highly comminuted, and as such, they could not be classified. Soeur et al. recommended operative management of displaced intraarticular fracture of the calcaneus, but their clinical results did not correlate with the proposed classification scheme [15]. The advent of CT in the 1980s revolutionized the characterization and management of calcaneal fractures, leading to a better understanding of the fracture anatomy. Zwipp et al. [22] were the first to use information garnered fromCT imaging to classify calcaneal fractures. Their scheme, similar to previous classification systems based on radiographs, divided the entire calcaneus into a total of five possible fragments. They also incorporated the number of affected joint facets and the degree of soft tissue damage into a 12point scoring system that was of prognostic relevance [11]. In 1990, Crosby and Fitzgibbons [4] developed a classification system based on articular surface displacement (nondisplaced, displaced, and comminuted fractures). They were the first to correlate clinical outcomes with a CT-based classification scheme [4]. This clinical correlation was limited to nonoperative treatment of a calcaneus fracture; nonetheless, they were able to predict which fracture type would do well with closed treatment and which would not One of the authors (EM) received personal fees from Zimmer Biomet (Warsaw, IN, USA), outside the submitted work. Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. This work was performed at the University of Kentucky, Lexington, KY, USA.