The Megaendoprosthesis in Revision Arthroplasty - a Cost-revenue Analysis in the aG-DRG System

Abstract

Introduction

Megaendoprosthesis offer a viable treatment in complex revision arthroplasty cases with good functional outcome. In the context of a neoplastic indication, the diagnosis-related group (DRG) I95A is usually assigned with a relative weight of 4.906 (2021). In contrast, in revision arthroplasty, the appropriate DRG is assigned, depending on the joint replacement. The additional costs compared to the invoiced DRG are to be compensated by agreeing on hospital-specific individual fees. These complex revision arthroplasties set high technical and operative demands and are mainly performed in specialised departments. We conducted a cost-benefit analysis of the use of the megaendoprosthesis in revision cases in a specialised orthopaedic clinic, as a single centre study. The question we sought to answer was: Is cost recovery possible in the modified German DRG system (aG-DRG)?

Materials and Methods

A retrospective single centre analysis of treatment costs was performed. From 2018 to 2020, 113 patients treated with a megaendoprosthesis reconstruction in a referral centre due to extensive bone loss after aseptic or septic revision of a hip or knee prosthesis were included in the study. Relevant case-related cost drivers of the aG-DRG matrix (including staff and material costs of the operating theatre area and the ward) were taken into account. The actual costs were determined according to the specifications of the calculation manual published by the German institute for the remuneration system in hospitals (InEK). For each case, the contribution margin was calculated by relating the hospital’s internal costs to the corresponding cost pool of the aG-DRG matrix.

Results

According to the DRG system 2021, 17 different DRGs were used for billing – in 70% based on a patient clinical complexity level (PCCL) ≥ 4. Compared with the InEK calculation, there is a deficit of −2,901 € per case in the examined parameters. The costs of physicians show a shortfall in both the operating theatre and on the ward. Implant costs, which were supposed to be compensated by hospital-specific additional charges, show a hospital-specific shortage of −2,181 €. When analysing the risk factors for cost recovery, only these showed a significant difference.

Conclusion

Implantation of the megaendoprosthesis in revision arthroplasty is often the last option to preserve limb function. At present, despite a high degree of specialisation and process optimisation, this treatment cannot be provided cost-effectively even in tertiary care. The politically desired specialised department structure requires sufficient reimbursement for complex cases. The economic outcome of each treatment case is often unpredictable, however the surgeon is confronted with these cases and is expected to treat them. The high standard deviation indicates large differences in the cost/revenue situation of each individual case. Our results show for the first time a realistic cost analysis for megaprosthesis in revision arthroplasty and underline the importance of an adequate hospital-specific charge, individually agreed by the funding units. The calculation should include not only the implant costs, but also the increased staff costs (increased, complex planning effort, quality management, surgery time, etc.).

Keywords

megaendoprosthesis in revision arthroplasty - diagnoses-related group (DRG) - cost-benefit analysis

Publication History

Received: 01 June 2023

Accepted after revision: 11 September 2023

Article published online:
23 October 2023

• Literatur

• 1 Statistisches Bundesamt (Destatis). Fallpauschalenbezogene Krankenhausstatistik (DRG-Statistik) Operationen und Prozeduren der vollstationären Patientinnen und Patienten in Krankenhäusern bis zum kodierbaren Endpunkt 2021. 22.09.2022
• 2 Institut für Qualitätssicherung und Transparenz im Gesundheitswesen. Bundesqualitätsbericht 2022. Berlin: Institut für Qualitätssicherung und Transparenz im Gesundheitswesen; 2022. Accessed September 13, 2023 at: https://iqtig.org/downloads/berichte/2022/IQTIG_Bundesqualitaetsbericht-2022_2022–10–28.pdf
• 3 Bundesgeschäftsstelle Qualitätssicherung gGmbH. BQS Qualitätsreport 2005. Düsseldorf: Bundesgeschäftsstelle Qualitätssicherung gGmbH; 2006. Accessed September 13, 2023 at: https://www.bqs.de/default-wAssets/docs/reports/Qualitt-sichtbar-machen.-BQS-Qualittsreport_2005.pdf
• 4 Puttock DR, Howard DP, Eastley NC. et al. Apparent trends in the use of femoral megaprostheses: an analysis from the National Joint Registry. Arthroplasty 2022; 4: 50
• 5 Ghanem M, Schneider I, Zajonz D. et al. Management of Modular Mega-Implant Infection of the Lower Extremity. Z Orthop Unfall 2021; 160: 317-323
• 6 Sobol KR, Fram BR, Strony JT. et al. Survivorship, complications, and outcomes following distal femoral arthroplasty for non-neoplastic indications. Bone Jt Open 2022; 3: 173-181
• 7 Bundesinstitut für Arzneimittel und Medizinprodukte. Operationen- und Prozedurenschlüssel Version 2021. Accessed May 12, 2023 at: https://www.dimdi.de/static/de/klassifikationen/ops/kode-suche/opshtml2021/
• 8 Vaishya R, Thapa SS, Vaish A. Non-neoplastic indications and outcomes of the proximal and distal femur megaprosthesis: a critical review. Knee Surg Relat Res 2020; 32: 18
• 9 Di Martino A, Pederiva D, Bordini B. et al. Proximal femoral replacement for non-neoplastic conditions: a systematic review on current outcomes. J Orthop Traumatol 2022; 23: 18
• 10 Schmolders J, Koob S, Schepers P. et al. Tumorprothesen in der endoprothetischen Revisionschirurgie der unteren Extremität – Ergebnisse von 25 Patienten nach Versorgung mit einem modularen Tumor- und Revisionssystem (MUTARS®). Z Orthop Unfall 2017; 12: 61-66
• 11 Kasch R, Merk S, Drescher W. et al. Marginal contribution of UKS- versus TKA in varus arthritis of the knee. Arch Orthop Trauma Surg 2012; 132: 1165-1172
• 12 Institut für das Entgeltsystem im Krankenhaus GmbH. aG-DRG-Report-Browser 2021. Accessed May 12, 2023 at: https://www.g-drg.de/datenbrowser-und-begleitforschung/g-drg-report-browser/ag-drg-report-browser-2021
• 13 Institut für das Entgeltsystem im Krankenhaus GmbH. Abschlussbericht G-DRG-System 2014. Accessed May 12, 2023 at: https://www.g-drg.de/content/download/5188/file/Abschlussbericht_G-DRG-System2014.pdf
• 14 Institut für das Entgeltsystem im Krankenhaus GmbH. Handbuch zur Kalkulation von Behandlungskosten Version 4.0. Accessed May 12, 2023 at: https://www.g-drg.de/content/download/6489/file/Kalkulationshandbuch_4.0_20161010.pdf
• 15 Graulich T, Steimer D, Zhang D. et al. High complication and revision rates after total femoral replacement: a retrospective single center analysis of indication, function, and complication. Arch Orthop Trauma Surg 2019; 139: 913-920
• 16 Viste A, Perry KI, Taunton MJ. et al. Proximal femoral replacement in contemporary revision total hip arthroplasty for severe femoral bone loss: a review of outcomes. Bone Joint J 2017; 99-B: 325-329
• 17 Höll S, Schlomberg A, Gosheger G. et al. Distal femur and proximal tibia replacement with megaprosthesis in revision knee arthroplasty: a limb-saving procedure. Knee Surg Sports Traumatol Arthrosc 2012; 20: 2513-2518
• 18 Aprato A, Tosto F, Comba A. et al. The clinical and economic burden of proximal femur periprosthetic fractures. Musculoskelet Surg 2022; 106: 201-206
• 19 Regierungskommission für eine moderne und bedarfsgerechte Krankenhausversorgung. Dritte Stellungnahme und Empfehlung der Regierungskommission für eine moderne und bedarfsgerechte Krankenhausversorgung. Accessed May 12, 2023 at: https://www.bundesgesundheitsministerium.de/fileadmin/Dateien/3_Downloads/K/Krankenhausreform/3te_Stellungnahme_Regierungskommission_Grundlegende_Reform_KH-Verguetung_6_Dez_2022_mit_Tab-anhang.pdf
• 20 Ministerium für Arbeit Gesundheit und Soziales des Landes Nordrhein-Westfalen. Krankenhausplan Nordrhein-Westfalen 2022. Accessed May 12, 2023 at: https://www.mags.nrw/sites/default/files/asset/document/krankenhausplan_nrw_2022.pdf
• 21 Wirtz DC, Stöckle U. Editorial. Z Orthop Unfall 2020; 158: 583-585