Impingement in total hip arthroplasty: A geometric model

Abstract

Total Hip Arthroplasty (THA) is one of the most common and successful surgical interventions. The survivorship at 10 years for the most commonly used systems is over 95%. However, the incidence of revision is usually much higher in the 0–1 year time period following the intervention. The most common reason for revision in this early time period is dislocation and subluxation, which may be defined as complete or permanent, and partial or temporary loss of contact between the bearing surfaces respectively. This study comprises the development of a geometric model of bone and an in situ total hip replacement, to predict the occurrence and location of bone and component impingement for a wide range of acetabular cup positions and for a series of frequently practiced activities of daily living. The model developed predicts that anterior-superior component impingement is associated with activities that result in posterior dislocation. The incidence may be reduced by increased cup anteversion and inclination. Posterior-inferior component impingement is associated with anterior dislocation activities. Its incidence may be reduced by decreased cup anteversion and inclination. A component impingement-free range was identified, running from when the cup was positioned with 45° inclination and 25° anteversion to 70° inclination and 15°–20° anteversion.

Is It Necessary to Obtain Lateral Pelvic Radiographs in Flexed Seated Position for Preoperative Total Hip Arthroplasty Planning?

“…Investigators have shown the importance of hip-spine relations and how differences in pelvic tilt in different positions can affect the risk of THA impingement [ 1 , 3 , 6 , 16 , [20] , [21] , [22] ]. Computer simulations and preoperative planning software have been developed to optimize the orientation of acetabular implants by considering sagittal pelvic tilt [ [23] , [24] , [25] , [26] , [27] , [28] , [29] ]. Many of these software programs concentrate on pelvic tilt in standing and relaxed sitting positions, but sagittal pelvic tilt in flexed seated positions is not always considered.…”

Elucidation of target implant orientations with the safety range of hip rotation with adduction or abduction during squatting: Simulation based on in vivo replaced hip kinematics

“…Eighth, only one activity rising from a squatting position was considered, and a specific recommendation for target orientations of components in this study could not be adapted to the other activities, such as leg cross, stooping, pivoting, and lunging. Target orientations of components need to be a compromise to satisfy the disparate requirements of different activities (Nadzadi et al, 2003;Pryce et al, 2022).…”

Phantom validation of a novel RSA-based impingement metric to assess component-on-component impingement risk

“…Because of its consequences, many clinical studies are looking at methods to reduce risk of impingement following hip 1 arthroplasty. 5,[8][9][10] Currently, reducing impingement is being achieved via implant design, improved templating, and intra-operative technologies such as navigation.…”