Aseptic Loosening on Acetabular Side

Acetabular bone defects are frequently encountered in revision total hip arthroplasty (THA). Bone defects could be quite severe, even pelvic discontinuity (PD), which is an intractable condition for many surgeons. Paprosky classification (Table 3.1) is commonly used in the clinical evaluation of acetabular bone defects. To understand the Paprosky classification, one must be familiar with the important anatomical markers on which it is based. The Paprosky classification of acetabular bone loss was based on four reference indicators: (1) the location of the hip rotation center or the dislocate distance between the hip rotation center and the superior obturator foramen line; (2) the degree of teardrop damage; (3) the degree of osteolysis of the ischial ramus; and (4) the integrity of Kohler line. Anatomical markers are shown in Fig. 3.1.