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
