Femoral Bone Classification Essay

CLASSIFICATION OF FEMORAL DEFICIENCY Of the numerous available classification systems for femoral deficiency, the two most commonly used are the American Academy of Orthopedic Surgeons (AAOS) classification (Table 1) [30] and the Paprosky classification (Table 2) [31-33]. The AAOS classification is simple and can be used to describe femoral bone deficiencies in both primary and revision settings. The Paprosky classification (Figure 2) correlates well with surgical complexity, can assist in predicting reconstruction options, and is solely utilized in the revision setting. Therefore, we prefer to use this classification when describing femoral bone loss prior to revision surgery. Type I defects (Figure 3) present with essentially normal femoral bone stock. These are often seen in isolated acetabular component revisions and may be managed with …show more content…

Type II (Figure 4) defects are the most commonly encountered. In this scenario, the loss of metaphyseal bone combined with an intact diaphysis precludes the use of standard length implants. While metaphyseal bone loss can be considerable, a type II defect may still contain enough proximal bone to provide metaphyseal support. Common reconstructive options for type II deficiencies include modular metaphyseal engaging stems (with or without sleeves), diaphyseal fit-and-fill stabilizing stems, or long, fully porous coated stems [32]. Type III (Figure 5) defects are further subclassified by the amount of intact diaphyseal bone remaining. Type IIIA defects have ≥4 cm of intact diaphysis, whereas type IIIB defects have <4 cm of intact diaphysis. The reconstruction options are significantly more complex in these scenarios due to the need for adequate distal fixation. When considering using modular cementless stems in type IIIA/B femoral defects, most authors recommend obtaining at least 4 cm of distal fixation. With decreasing distal bone stock, the native femoral bow must be