Management of pelvic discontinuity in revision arthroplasty

Acetabular defect classification and management

“…When grading acetabular defects in revision arthroplasty after THR there is a need for a universal and valid system [17]. Precise classification of acetabular defects has always been a complex problem [7,17]. Therefore, it is vital to provide a classification system that reliably describes the criteria of the acetabular structure and directly relates to surgical management.…”

“…Table 3) is based on the presence or absence of supporting structures, such as the acetabular rim, superior dome, medial wall, anterior and posterior columns, and the surgeon's assessment of these structures' capacity to support the revision prosthesis [19]. This classification system gained wide acceptance [7,22]. The original classification system was developed by evaluating 147 patients with AP X-ray imaging, classifying each as type I, II, or III [19].…”

“…bone defects and the insufficient documentation of the initial clinical findings [6,7,13,15,22]. There are several published classification systems for acetabular bone defects in THA [1,3,5,11,12,19,20].…”

“…Important additional information about the anterior and posterior acetabular columns can only be obtained by means of special X-ray techniques through the ala and obturator views, as well as in the faux profile view. Computer tomographic imaging, although limited by metal artifacts, still provides further information on the intraoperative need for special implants or bone grafts; however, it is only the intraoperative finding after the removal of the implants that provides complete clarity of the bony configuration of the acetabulum [7,9]. A practical, reproducible and valid classification system is needed not only for preoperative planning but above all for scientific evaluations and comparisons.…”

“…Comment on type III: in cases of implantation of a revision cup with cranial strap and iliac stem, the iliac stem itself is an essential point of fixation. In cases of implantation of the a cup-cage system, the dome screw is an essential point of fixation.Green points point of contact with no fixation: type I treated with a spherical multihole cup (DePuy-Synthes); type II treated with an oval cup (AQ Implants, currently AQ Solutions GmbH); type III treated with a revision cup with cranial strap and iliac stem, AQ Implants, currently AQ Solutions GmbH) or with a cup-cage system (Peter Brehm GmbH); type IV treated with a custom-made partial pelvic replacement (AQ Implants, currently AQ Solutions GmbH) scribed in the literature as too coarse, too confusing or too complex [1,7,9]. The purpose of this study was to provide a practical and contemporary classification system that is reliable and pragmatic with respect to perioperative evaluation, planning, scientific comparison and analysis.…”