Rockwood, Green, and Wilkins' Fractures, 10e Package

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SECTION ONE • General Principles

clearly play a role in the future of classifications and ideally the treatment of fractures. The Neer classification was deemed valuable at the time of its creation; however, with routine use of CT imaging in the proximal humerus, how will that affect the future of classification? The Sanders classification has since replaced the previously widely adopted Essex-Lopresti classifi cation due to incorporation of CT imaging. Pelvic ring stability is regularly debated following high and low energy fractures; thus, with MRI accessibility, will future classifications incorpo rate soft tissue injury and correlate with surgical treatment? THE GUSTILO–ANDERSON CLASSIFICATION Open fractures present unique treatment challenges to ortho paedic surgeons and unique challenges to classification. Given the importance of soft tissue wounds associated with such fractures, the wide variation in severity of these injuries and the known effect of this variation on prognosis, this is a very important area to have good classification. However, not all of the important information is present on radiographs, and this presents challenges to designing and assessing classifications. The following section will illustrate issues present in historical classifications and to describe a modern process that has been undertaken to improve classification of open fractures. It also illustrates the difficulty of replacing entrenched classification language. Fractures that are exposed to environmental contamination through disruption of the soft tissue envelope have been shown to have increased risks of infection, delayed union, nonunion, and even limb amputation. 16,21 A variety of factors have been found to contribute to the complications associated with open fractures. Classification systems have been developed to char acterize these injuries and to account for the most important of these factors. The most notable of these from a historic con text is the open fracture classification that was described in tibia fractures by Gustilo and Anderson Table 5-4. 21,22 The Gustilo and Anderson system has withstood the test of time likely owing to its simplicity and ability to quickly stratify severity of injury. 22 Several studies have shown that this system OPEN FRACTURES

demonstrates only moderate interobserver agreement. 5,24 In one study, Brumback et al. distributed a survey to 245 orthopaedic surgeons, asking them to classify 12 open fractures of the tibia based upon a video presentation. The level of agreement for the classification of each fracture was determined according to the largest percentage of observers who chose a single classifica tion type. The average agreement among the observers for all 12 fractures was 60%, with the overall agreement for each fracture ranging from 42% to 94%. 5 There are several reasons why this classification has poor observer agreement. There is a lack of precision in describing different injury characteristics of open fractures allowing for interpretation of how the open fracture should be classified, that is, a fracture with a small wound but extensive periosteal stripping. In addition, the treatment can actually dictate the appropriate classification, such as the abil ity to close a traumatic wound, a decision often left to the dis cretion of the treating surgeon, which distinguishes between a type IIIA and type IIIB open fracture. In an attempt to build on the reliability and validity of the Gustilo and Anderson open fracture classification, the OTA Classification Committee underwent an extensive process which included the review of available evidence, the identification of 34 factors which were placed in a preliminary rank order of factor importance, and then modified through consensus expert opinion from an Open Fracture Study Group of the OTA, 45 who ultimately selected the five most essential categories of open fracture severity establishing the new OTA/AO Open Fracture Classification (OTA-OFC; Table 5-5). It consists of five catego ries of injury: skin injury (S), muscle injury (M), arterial injury (A), bone loss (B), and contamination (C) with each of these categories further stratified into three subcategories according to injury severity (mild, moderate, and severe). The interobserver reliability of the OTA-OFC in most catego ries has been determined to be good to excellent. 1 In one study, 136 independent raters comprising 91 attending surgeons and 45 resident surgeons reviewed six videos of various open frac tures. In addition to excellent reliability, this classification has been shown to provide prognostic information. The OTA-OFC has been shown to aid in the prediction of short-term complica tions in open fracture management, such as infection, amputa tion, number of debridements, and wound healing at a single in stitution 2 and across multiple institutions. 27 A large retrospective study utilizing the Gustilo–Anderson classification and the OTA OFC for assessments of open fractures found that the Gustilo– Anderson classification demonstrated no correlations with any of the postoperative complications measured; however, they found that the OTA-OFC skin injury component was an independent predictor of limb amputation. Furthermore, they commented that a summative OTA-OFC score ≥10 best correlated with need for amputation. While expanding evidence demonstrates superiority of the OTA-OFC in both reliability and predictive ability to aid clinicians in treatment of these challenging inju ries, further evidence will be needed to determine its true utility. OPEN FRACTURES AND THE OTA/AO OPEN FRACTURE CLASSIFICATION

TABLE 5-4. Gustilo–Anderson Classification of Open Fractures

Type I

<1 cm

Type II

1–10 cm

Type III

>10 cm

Type IIIA

High energy regardless of wound size

Type IIIB

Periosteal stripping and bone exposure associated requiring flap coverage

Type IIIC

Associated vascular injury requiring repair