Use of computed axial tomography to determine the correct alignment of prosthetic components in primary hip arthroplasty A single-center observational study.

Abstract

Introduction: Correct placement and alignment of hip prosthetic components are critical for optimal short—and long-term results. Among the factors influencing biomechanics is femoral and acetabular anteversion, which decreases the risk of dislocations. This study aimed to determine by tomographic study the angles of femoral and acetabular anteversion of the prosthetic components after hip arthroplasty to avoid dislocation in the Traumatology and Orthopedics Service of the Alcivar Clinic in the period June 2022 - 2023.

Methods: This is a descriptive, retrospective study of the Alcivar Clinic's Traumatology and Orthopedics Service from 2022 to 2023.

Results: Twenty-one patients were analyzed with average acetabular anteversion of 14° ± 8 (6 - 22), 15° in men and 12° in women; average femoral anteversion of 18° ± 10 (8 - 28), 18° in men and 20° in women, with average combined anteversion of 33° ± 14 (21 - 47), 33 for male and female gender.  Of 5 early dislocations and 2 late dislocations, 4 posterior dislocations (<21°) and 3 anterior dislocations (>47°), functionality with the modified Harris scale, with excellent to good results (80 - 95 %).

Conclusions: CT is a valuable and reliable tool for determining the correct alignment of prosthetic components in the hip in patients undergoing CTA. Early dislocations are unrelated to acetabular and femoral anteversion; multifactorial causes should be considered.