Antibiotic-loaded hip spacers in two-stage revision for chronic hip periprosthetic joint infection: comparative outcomes in a multimorbid rheumatic cohort from 2008 to 2023

Background: Periprosthetic joint infection (PJI) after total hip arthroplasty causes repeated surgery, prolonged antimicrobial therapy, functional decline, and high morbidity. Management is difficult in complex multimorbid patients with inflammatory rheumatic disease because immunosuppression, overlapping comorbidities, and disease flares may obscure diagnosis and compromise recovery. We described the institutional burden of chronic hip PJI requiring spacer-based two-stage revision and compared articulating versus static antibiotic-loaded hip spacers. Methods: We performed a single-center retrospective cohort study of consecutive adults treated from 2008 to 2023 for chronic hip PJI with implant removal, antibiotic-loaded spacer placement, and planned two-stage revision. Patients were grouped by spacer construct. Spacer choice was pragmatic and non-randomized, reflecting intraoperative anatomy, rehabilitation potential, surgeon assessment, and construct/material availability. Functional outcomes, pain, range of motion, perioperative variables, microbiology, failure patterns, comorbidity burden, and follow-up were evaluated using complete-case denominators. Results: Among 511 hip arthroplasty procedures, 31 chronic hip PJI cases requiring spacer-based two-stage revision were identified, corresponding to 6.1% of recorded hip procedures (95% CI, 4.3–8.5%). Two patients declined participation, leaving 29 patients for comparative analysis; 22 (75.9%) received an articulating spacer, and 7 (24.1%) received a static spacer. Source-case comorbidity coding showed frequent multimorbidity, including rheumatic disease, diabetes, hypertension, steroid exposure, hypothyroidism, and neoplasia. Mean follow-up was 7.9 +/- 4.8 years in the articulating group and 10.8 +/- 6.9 years in the static group. The articulating group improved significantly in WOMAC, Harris Hip Score, and NPRS, whereas functional changes in the static group were limited. In reimplanted patients, static spacers were associated with greater blood loss, longer operative time, and higher residual pain. Staphylococcus aureus was the most frequent isolate. Conclusions: Chronic hip PJI requiring spacer-based two-stage revision represented a clinically relevant burden in this complex tertiary referral cohort. Articulating spacers were associated with greater improvements in function and pain than static spacers, but findings remain exploratory and require confirmation in larger matched or prospective cohorts. Clinical trial number: not applicable.