Systematic measurement of spino-pelvic alignment as a simple strategy to reduce the dislocation rate in primary hip arthroplasties.

Abstract

The incorporation of spinopelvic alignment measurement in the planning of primary hip arthroplasties is a simple and low-cost method whose isolated impact on reducing dislocation rates has not been clearly established. The objective was to estimate the probability of dislocation and its occurrence rate by comparing 2 demographically similar populations, 1 with the measurement incorporated and the other without it. Additionally, the modification and distribution of surgical practices and indications aimed at reducing the risk of dislocations were compared. A before-and-after study with prospective registry and retrospective control group was designed. We compared 693 patients (prospective registry) with the incorporation of spinopelvic alignment measurement in preoperative planning versus 341 from a previous period who constituted the control group (retrospective registry). All had a minimum follow-up of 2 years. The dislocation rate significantly decreased from 3.2% to 0.7%, with an OR of 0.22 for dislocation in the intervention group. There was a significant increase in the use of dual-mobility components in patients with complete misalignment and stems with extended offset in patients with partial misalignment. In conclusion, the incorporation of spinopelvic alignment measurement in preoperative planning is an accessible method for any medical centre that contributed to modifying surgical practices, ultimately leading to a significant reduction in the dislocation rate.