Rationale for the use of the original classification of posttraumatic acetabular deformities in primary total hip replacement

Abstract. Introduction Analysis of publications on primary hip replacement shows lower survival rates in patients with acetabular injuries. With the lack of a unified system for assessing post-traumatic acetabular deformities, authors tend to use the available classifications of acute pelvic trauma (AO/ ASIF, Young & Burgess, Tile, etc.) and acetabular osteolysis (AAOS, DGOT, Gross and Saleh, Paprosky), which we think can be inappropriate with the classifying systems meant for different patterns of acetabular deficiency. Material and methods CT scans of 117 patients with posttraumatic acetabular deformities were reviewed prior to total hip replacement (THR) performed for posttraumatic grade III coxarthrosis. The displacement of acetabular walls was determined with the measurements tabulated and analyzed. Results An original "ASPID" classification of post-traumatic deformities based on the findings obtained was offered with use of three assessment criteria: localization of the deformity, extent of displacement and the integrity of the pelvic ring. The ASPID classification can be used for the localization of the deformity with anterior (A), superior (S), posterior (P) and inner acetabular walls (I) to be identified. Measurements of displacement ranging 0-5 mm suggests grade 0 displacement; 6-15 mm, grade 1 displacement and greater than 15 mm, grade 2 displacement. The integrity of the pelvic ring evaluated from the involvement side as D0 suggests maintained pelvic integrity and D1, broken pelvic integrity. An acetabular hardware would be marked with 'H'. Conclusion ASPID classification is easy to use and has shown to be practical for planning of primary THR after acetabular fracture.