Hospital cost structures and resource utilisation across representative treatment pathways relevant to complex orthopaedic infection care: a nationwide DRG-based analysis in Germany

Purpose Implant-associated orthopaedic infections require prolonged inpatient treatment, repeated surgery and multidisciplinary care, yet nationwide evidence on how hospital resources are distributed across clinically distinct treatment pathways is limited. This study characterised hospital-side case costs, resource utilisation and aggregate expenditure across representative German diagnosis-related groups (DRGs) relevant to complex orthopaedic infection care. Methods Publicly available 2024 data from the German Institute for the Hospital Remuneration System (InEK) were analysed. Twelve representative DRGs were selected a priori from official definitions and diagnostic/procedural profiles and grouped into six treatment pathways. The InEK cost matrix reflects standardised hospital-side resource costs from participating calculation hospitals and does not represent actual DRG reimbursement. National case frequencies, length of stay and mean case costs were analysed using frequency-weighted pathway estimates, while pathway-level cost composition was calculated from aggregate component expenditure. Results The included DRGs represented 36,212 hospitalisations and €305.2 million in aggregate annual hospital-side expenditure represented by the selected DRGs. Mean hospital-side costs ranged from €5,859 to €22,495 per case. Ward care accounted for approximately 34–69% of pathway expenditure; operating theatre services contributed up to 39% in revision arthroplasty. Geriatric rehabilitation generated the largest aggregate expenditure (€119.0 million; 39.0%) because of high case volume, whereas complex vacuum-assisted wound care had the highest per-case cost but only 2.9% of aggregate expenditure. At the aggregated DRG level, mean length of stay was associated with mean case cost (Pearson r = 0.87, 95% CI 0.60–0.96; P < 0.001); leave-one-out correlations ranged from r = 0.79 to r = 0.96. Conclusion Resource requirements differ markedly across representative DRG pathways relevant to complex orthopaedic infection care. Because the selected DRGs are not infection-exclusive, the reported expenditure should not be interpreted as the national economic burden of implant-associated orthopaedic infection. The findings may inform hospital resource planning and future cost–revenue analyses.