Comparing Clinical and Radiological Outcomes for a Three-Dimensional Printed Highly Porous Cup and a...

Total hip arthroplasty (THA) is a widely used treatment for hip joint degeneration. While the use of highly-porous acetabular components in THA has increased, the long-term clinical and radiological benefits of these implants remain unclear. Prior research has shown that hydroxyapatite (HA)-coated non-highly-porous cups are a standard option in THA. However, the introduction of 3D-printed highly-porous cups has raised questions about their performance in comparison. This gap motivated the need to evaluate whether the newer 3D-printed implants offer equivalent or superior outcomes. No prior work had resolved the comparative effectiveness of these two cup types in CT-based navigated THA. Understanding the differences in clinical and radiological outcomes is essential for guiding implant selection. The study aimed to address this uncertainty by analyzing a matched cohort of patients. This approach allows for a more accurate comparison of the two cup types. The findings could help surgeons make informed decisions when choosing between these implant options.

This study aimed to compare the clinical and radiological outcomes of 3D-printed highly-porous cups and HA-coated non-highly-porous cups in CT-based navigated total hip arthroplasty. The specific problem addressed was the lack of direct evidence on the effectiveness of 3D-printed implants in this context. The motivation for the study was to determine whether the newer 3D-printed cups offer comparable or superior outcomes to the traditional HA-coated cups. The researchers focused on outcomes such as cup orientation, migration, and radiolucent lines. The study also evaluated clinical scores to assess patient-reported outcomes. The need for this comparison arises from the increasing use of 3D-printed implants in orthopedic surgery. By using a matched cohort design, the researchers aimed to reduce bias and improve the validity of their findings. This approach allows for a more accurate assessment of the two cup types in a real-world setting.

The study used a retrospective design to compare 3D-printed highly-porous cups with HA-coated non-highly-porous cups in CT-based navigated THA. Researchers analyzed data from 196 hips in 175 patients, with 112 hips in the highly-porous group and 84 in the HA-porous group. Propensity score matching was applied to balance age, sex, diagnosis, and surgical approach between the groups, resulting in 66 hips in each. Clinical outcomes were measured using the Japanese Orthopaedic Association hip (JOA) score and the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) at multiple time points. Radiological outcomes included cup orientation, positioning, initial gap, migration, loosening, and radiolucent lines. 3D templating software was used to assess cup placement. Statistical analysis compared the two groups for differences in clinical and radiological outcomes. The study design allowed for a direct comparison of the two cup types in a real-world clinical setting.

After two years, clinical outcomes did not differ significantly between the two groups. The mean absolute error for cup inclination was 2.9 ± 2.3° in the highly-porous group and 2.6 ± 2.2° in the HA-porous group. The mean absolute error for anteversion was 2.7 ± 2.0° in both groups. No migration or loosening was observed in either group during the study period. The incidence of initial gap was significantly higher in the highly-porous group (27.3%) compared to the HA-porous group (12.1%). Radiolucent lines (RLLs) showed a progressive decline in both groups over the two-year follow-up. There were no significant differences in RLLs at the two-year mark. The 3D-printed highly-porous cups demonstrated excellent radiological outcomes. These findings suggest that the two cup types perform similarly in the short to mid-term.

The two-year clinical outcomes and radiological evaluations of 3D-printed highly-porous cups and HA-coated non-highly-porous cups were comparable. The study found no significant differences in clinical scores between the two groups. The mean absolute error for cup orientation did not differ significantly between the groups. No migration or loosening was observed in either group during the study period. The incidence of initial gap was higher in the highly-porous group, but this did not affect long-term outcomes. Radiolucent lines showed a progressive decline in both groups. The authors propose that the 3D-printed cups offer excellent radiological outcomes. These findings support the use of 3D-printed highly-porous cups in CT-based navigated THA.