Preoperative planning for hip arthroplasty considering the structural features of the spinopelvic complex

Total hip arthroplasty (THA) is clinically one of the most successful surgeries, with its frequency steadily increasing due to the growing incidence of primary coxarthrosis [1,2]. It is estimated that around 5% of these procedures are complicated by instability and dislocations, despite the positioning of the prosthetic head within the "safe zone" [15-18]. With this prosthesis positioning, complications are most commonly found in patients with a rigid spine [37]. Preoperative assessment, including radiography of the lumbar spine and hip joint in lateral view in standing and sitting positions, with evaluation of sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis, and other parameters of the spinopelvic complex, allows for more precise planning of prosthesis positioning and reduces the risk of dislocation [13, 19]. Spinal stiffness may be increased in patients over 65 years old, in cases of ankylosing spondylitis, or following prior spinal fusion. In such cases, it is recommended to increase cup inclination and anteversion to compensate for the reduced posterior pelvic tilt in the sitting position [46]. In this review, we present various classifi ations of spinopelvic complex deformities and recommendations for cup positioning in total hip arthroplasty. A more personalized approach can reduce the risk of prosthetic instability and the number of revision surgeries [55].