The prevalence of the various patterns of spinopelvic abnormalities that increase the risk for prosthetic impingement is unknown. While prior surgery or lumbar fusion are recognized as a risk factors for postoperative dislocation, many patients presenting for THA do not have obvious radiographic abnormalities. The purpose of this study is to determine the prevalence of large posterior pelvic tilt (PPT) when standing, stiff lumbar-spine (SLL) and spino-pelvic sagittal imbalance (SSI) in patients undergoing primary THA. A consecutive series of 1592 patients (56% female) over 2 years underwent functional analysis of spinopelvic mobility using CT, standing, and flexed seated lateral radiographs as part of pre-operative THA planning. The average age was 65 (20–93). We investigated the prevalence of these 3 validated spinopelvic parameters known to increase the risk for impingent and correlated them to the patient's age and gender using Chi squared analysis. Finally, the risk of flexion and extension impingement was modeled for each patient at a default supine cup orientation (DSCO) of 40°/20° (±5°).Introduction
Methods
