Innovative Technologies for Salvage Procedures of Failed Treatments of Osteoarthritis: Biomimetics Solutions (CustomPN)

In this prospective multicenter study, a population of adult individuals consecutively treated for revision hips, requiring a custom-made acetabular implant for non-oncological reasons, will be included. The custom-made implant is a personalized implant produced using additive manufacturing, based on the pre-operative CT scan that details the bone damage. Patients eligible for this implant are those with severe acetabular bone damage Paprosky 3 (loss of the superolateral part and one of the two ventro-caudal walls).

Preoperatively, the patient will undergo a clinical evaluation. Data will be collected on the patient's general health status with the Charlson score, the reason for revision, number of revisions, type of implant in place, and the time elapsed between the failed implant and the revision in question. The bone deficit will be studied through CT measurements according to qualitative and quantitative scales. During the surgery, information on intraoperative complications will be collected. In the postoperative period, perioperative complications will be collected according to the Clavien Dindo classification. The clinical radiographic evaluations will be carried out during outpatient follow-up visits at 1, 3, 12, 24, and 36 months after revision. They include the Harris Hip Score clinical score, the EQ-5D PROM, and the patient's satisfaction level (qualitative assessment in 4 grades: unsatisfied, slightly satisfied, moderately satisfied, fully satisfied). The positional parameters of the implant will be evaluated, as compared to the immediate post-operative X-ray: acetabular abduction, acetabular anteversion, center of rotation height, center of rotation medialization, and inclination of the custom-made component. From 12 months onwards, the osteointegration characteristics of the component will be assessed: presence of radial trabeculae at the interface, superolateral and inferior reinforcements, stress shielding, absence of radiolucent lines. Re-revision rates will be determined using the Kaplan-Meier method. The reasons for re-revision will be noted.