Economic analysis of two-stage septic revision after total hip arthroplasty: What are the relevant costs for the hospital's orthopedic department?

Intrawound Vancomycin Powder in Primary Total Hip Arthroplasty: A Prospective Quality Control Study

BACKGROUND

The purpose of this retrospective analysis of a prospective quality control project was to determine whether the use of intrawound vancomycin powder (IVP) decreases the rate of periprosthetic joint infection (PJI) within 90 days following primary total hip arthroplasty (THA).

METHODS

From October 2021 to September 2022, a prospective quality control project was undertaken in which 10 high-volume THA surgeons alternated between using and not using IVP each month while keeping other perioperative protocols unchanged. A retrospective analysis of the project was performed to compare the group of patients who received IVP to the group of patients who did not. The primary outcome was a culture positive infection within 90 days following primary THA. Secondary outcomes included gram-positive culture, overall reoperation rate, wound complications, readmission, and wound complications within 90 days post-operatively. A total of 1,193 primary THA patients were identified for analysis. There were 523 (43.8%) patients who received IVP and were included in the IVP group, while 670 (56.2%) did not and were included in the non-IVP group. Age, body mass index, and sex were similar between the 2 groups (P > .25).

RESULTS

The IVP group had a higher rate of culture positive joint infections (1.7 [0.8, 3.2] versus 0.3% [0.04, 1.1], P = .01) than the non-IVP group. All PJI's were found to have gram positive bacteria in both groups. The IVP group had a higher overall reoperation rate than the non-IVP group (6.1 [4.2, 8.5] versus 2.4% [1.4, 3.9], P < .01). The IVP group had a higher reoperation rate for any wound complication compared to non-IVP patients (2.7 [1.5, 4.5] versus 0.7% [0.2, 1.7], P < .01). The overall readmission rate (6.1 [4.2, 8.5] versus 2.8% [1.7, 4.4], P < .01), as well as readmission for suspected infection (2.1 [1.1, 3.7] versus 0.6% [0.02, 1.5], P = .03), were higher in the IVP group.

CONCLUSIONS

The use of IVP in primary THA was associated with a higher rate of PJI, overall reoperation, reoperation for wound complications, and readmission in a prospective quality control project. Until future prospective randomized studies determine the safety and efficacy of IVP in THA conclusively, we advocate against its utilization.

Direct Hospital Costs per Case of Periprosthetic Hip and Knee Joint Infections in Europe - A Systematic Review

BACKGROUND

The rise of periprosthetic joint infections (PJIs) due to aging populations is steadily increasing the number of arthroplasties and treatment costs. This study analyzed the direct health care costs of PJI for total hip arthroplasty and total knee arthroplasty (TKA) in Europe.

METHODS

The databases PubMed, Scopus, Embase, Cochrane, and Google Scholar were systematically screened for direct costs of PJI in Europe. Publications that defined the joint site and the procedure performed were further analyzed. Mean direct health care costs were calculated for debridement, antibiotics, and implant retention (DAIR), one-stage, and 2-stage revisions for hip and knee PJI, respectively. Costs were adjusted for inflation rates and reported in US-Dollar (USD).

RESULTS

Of 1,374 eligible publications, 12 manuscripts were included in the final analysis after an abstract and full-text review. Mean direct costs of $32,933 were identified for all types of revision procedures for knee PJI. The mean direct treatment cost including DAIR for TKA after PJI was $19,476. For 2-stage revisions of TKA, the mean total cost was $37,980. For all types of hip PJI procedures, mean direct hospital costs were $28,904. For hip DAIR, one-stage and 2-stage treatment average costs of $7,120, $44,594, and $42,166 were identified, respectively.

CONCLUSIONS

Periprosthetic joint infections are associated with substantial direct health care costs. As detailed reports on the cost of PJI are scarce and of limited quality, more detailed financial data on the cost of PJI treatment are urgently required.

Impact of spinal Anaesthesia versus general Anaesthesia on the incidence of surgical site infections after knee or hip arthroplasty: A meta-analysis

Postoperative Surgical Site Infections (SSIs) pose significant challenges to recovery after joint arthroplasty. This systematic review and meta-analysis aim to compare the incidence of SSIs after knee or hip arthroplasty under Spinal Anaesthesia (SA) versus general anaesthesia (GA). We conducted the systematic review and meta-analysis following the PRISMA guidelines, analysing data from 15 studies selected from PubMed, Embase, Web of Science, and Cochrane Library up to May 16, 2023. The analysis included studies comparing SSIs incidence in patients aged 18 years and above who underwent knee or hip arthroplasty under SA or GA. Quality assessment was performed using the Cochrane Collaboration's risk of bias tool. The effect size was calculated using random or fixed-effects models based on the observed heterogeneity. We assessed the heterogeneity between studies and conducted a sensitivity analysis. Of 1651 initially identified studies, 15 articles encompassing 353 169 patients were included in the final analysis. A total of 156 405 patients were under SA, while 196 764 received GA. The studies demonstrated substantial heterogeneity (p = 0.007, I2  = 53.7%), resulting in a random-effects model being employed. Patients receiving SA showed a 23% lower likelihood of developing SSIs postoperatively compared to GA patients (OR: 0.77, 95% CI: 0.70-0.86, p < 0.001). Sub-group analysis further confirmed these findings regardless of the type of joint arthroplasty. This meta-analysis indicated a significantly lower incidence of SSIs following knee or hip arthroplasty under SA compared to GA. Despite observed heterogeneity, the results underscore the potential benefit of SA over GA in orthopaedic surgeries to reduce the risk of SSIs.

Cost-effectiveness of implant movement analysis in aseptic loosening after hip replacement: a health-economic model

OBJECTIVE

To investigate the cost-effectiveness of using Implant Movement Analysis (IMA) to follow up suspected aseptic loosening when the diagnosis after an initial X-ray is not conclusive, compared with a diagnostic pathway with X-ray follow-up.

METHODS

A health-economic model in the form of a decision tree was developed using quality-adjusted life years (QALY) from the literature, cost-per-patient data from a university hospital and the probabilities of different events from expert physicians' opinions. The base case incremental cost-effectiveness ratio (ICER) was compared with established willingness-to-pay thresholds and sensitivity analyses were performed to account for assumptions and uncertainty.

RESULTS

The base case ICER indicated that the IMA pathway was cost effective (SEK 99,681, compared with the SEK 500,000 threshold). In the sensitivity analysis, the IMA pathway remained cost effective during most changes in parameters. ICERs above the threshold value occurred in cases where a larger or smaller proportion of people receive immediate surgery.

CONCLUSION

A diagnostic pathway using IMA after an inconclusive X-ray for suspected aseptic loosening was cost effective compared with a pathway with X-ray follow-up.

Economics of Total Hip Arthroplasty: Review

This review article focuses on issues of economic analysis in providing care to patients requiring total hip arthroplasty. A large number of factors affecting the final financial result force us to look at economic research in the field of arthroplasty with a certain degree of criticality. At the same time, the existing financing systems cannot fully take into account all the possible costs arising from total hip arthroplasty. For this reason, studies concerning revision total hip arthroplasty are of particular interest, where treatment costs can vary significantly depending on the etiology and complexity of the case. These differences are reflected in the works of authors from France, Germany and Great Britain, who compared the treatment costs of patients with septic and aseptic revisions. Very different data both between countries and within the same country well demonstrate the need for a critical approach to the results of cost-effectiveness studies, QALYs based on Markov and other models, as the quality of the original data can be highly variable and reproduce the error of the initially incorrect price structure. At the same time, the rapidly increasing number of operations of primary and revision hip arthroplasty and, accordingly, the increasing economic costs of these operations require clear and effective economic criteria for their evaluation. The formation and application of these criteria will be the purpose of further research.

Time Required for Planned and Unplanned Episodes of Care in Septic Two-Stage Revision Hip and Knee Arthroplasty

BACKGROUND

Septic revision total hip (rTHA) and knee (rTKA) arthroplasty requires more effort but is reimbursed less than primary procedures per minute of intraoperative time. This study quantified planned and unplanned work performed by the surgical team for septic 2-stage revision surgeries during the entire episode-of-care "reimbursement window" and compared that time to allowable reimbursement amounts.

METHODS

Between October 2010 and December 2020 all unilateral septic 2-stage rTHA and rTKA procedures performed by a single surgeon at a single institution were retrospectively reviewed. Time dedicated to planned work was calculated over each episode of care, from surgery scheduling to 90 days postoperatively. Impromptu patient inquiries and treatments after discharge, but within the episode of care, involving the surgeon/surgeon team constituted unplanned work. Planned and unplanned work minutes were summed and divided by the number of patients reviewed to obtain average minutes of work per patient.

RESULTS

Sixty-eight hips and 64 knees were included. For 2-stage rTHA and rTKA the average time per patient for planned care was 1728 and 1716 minutes and for unplanned care was 339 and 237 minutes. Compared to the Centers for Medicare and Medicaid Services' allowable reimbursement times, an additional 799 and 887 minutes of uncompensated time was required to care for 2-stage rTHA and rTKA patients.

CONCLUSION

Two-stage revision procedures are substantially more complex than primary procedures. Financially disincentivizing surgeons to care for these patients reduces access to care when high-quality care is most needed. These findings support increasing the allowable times for 2-stage septic revision cases.

Trend of serum C-reactive protein is associated with treatment outcome of hip Periprosthetic joint infection undergoing two-stage exchange arthroplasty: a case control study

Background

Serum C-reactive protein (CRP) trends are critical for monitoring patients’ treatment response following a two-stage exchange arthroplasty for periprosthetic joint infection (PJI) of the hip. However, CRP trends are poorly described in the literature. The primary aim of this study was to identify the relationships between PJI treatment outcomes and our proposed CRP trend definitions, parameters, and microbiological data. The secondary aim was to investigate CRP trends after the occurrence of spacer-related complications.

Methods

We conducted a retrospective review of 74 patients treated with a two-stage exchange protocol for PJI in a tertiary referral joint center between 2014 and 2016. Patients with factors that may affect CRP levels (inflammatory arthritis, concomitant infections, liver and kidney diseases, and intensive care admissions) were excluded. CRP trends were categorized into five types and PJI treatment outcome was defined as “success” or “failure” according to the Delphi criteria.

Results

Treatment was successful in 67 patients and failed in 7 patients. Multivariate logistic regression analysis showed that type 5 CRP, defined as serum CRP fluctuation without normalization after first stage surgery (odds ratio [OR]: 17.4; 95% confidence interval [CI]: 2.3–129.7; p = 0.005), and methicillin-resistant Staphylococcus aureus (MRSA; OR: 14.5; 95% CI: 1.6–131.7; p = 0.018) were associated with treatment failure. Spacer-related complications occurred in 18 patients. Of these, 12 had elevated CRP levels at later follow-up, while six had no elevation in CRP levels.

Conclusions

We found that MRSA infection and type 5 CRP were associated with PJI treatment failure.

Case Report of a Diagnosed Septic Hip Joint Treated with a 2-Stage Hip Arthroplasty

Introduction

Identifying and determining appropriate treatment of adult hip septic arthritis (SA) can be quite challenging. Although rare, the annual incidence of this diagnosis is approximately 8 cases per 100,000 patients. The timing of patient symptoms is wide spread. The presentation may be acute, subacute, or even chronic, and moreover, the disease process may be masked by an underlying etiology. Once diagnosed, SA requires rapid and aggressive treatment.

Case Report

A 67-year-old patient presented with left hip pain. Physical examination shifted the differential diagnosis from osteoarthritis to a possible septic joint. Elevated inflammatory markers were revealed. Joint aspiration was obtained, which demonstrated rare Group G streptococcus. Two-stage hip arthroplasty was performed. Intra-operative cultures still reveal no growth of bacteria, and the patient is progressing well.

Conclusion

Adult septic hip arthritis is a rare diagnosis. Hence, a proper history, physical examination, infectious laboratory workup is important. The treatment of the condition is based on the duration of symptoms and the physician's clinical gestalt.

Inflation-Adjusted Medicare Reimbursement for Revision Hip Arthroplasty: Study Showing Significant Decrease from 2002 to 2019

BACKGROUND

Investigations into reimbursement trends for primary and revision arthroplasty procedures have demonstrated a steady decline over the past several years. Revision total hip arthroplasty (rTHA) due to infection (rTHA-I) has been associated with higher resource utilization and complexity, but long-term inflation-adjusted data have yet to be compared between rTHA-I and rTHA due to aseptic complications (rTHA-A). The present study was performed to analyze temporal reimbursement trends regarding rTHA-I procedures compared with those for rTHA-A procedures.

METHODS

The Centers for Medicare & Medicaid Services (CMS) Physician Fee Schedule Look-Up Tool was used to extract Medicare reimbursements associated with 1-stage and 2-stage rTHA-I as well as 1-stage rTHA-A procedures from 2002 to 2019. Current Procedural Terminology (CPT) codes for rTHA were grouped according to the American Academy of Orthopaedic Surgeons coding reference guide. Monetary values were adjusted for inflation using the consumer price index (U.S. Bureau of Labor Statistics; reported as 2019 U.S. dollars) and used to calculate the cumulative and average annual percent changes in reimbursement.

RESULTS

Following inflation adjustment, the physician fee reimbursement for rTHA-A decreased by a mean [and standard deviation] of 27.26% ± 3.57% (from $2,209.11 in 2002 to $1,603.20 in 2019) for femoral component revision, 27.41% ± 3.57% (from $2,130.55 to $1,542.91) for acetabular component revision, and 27.50% ± 2.56% (from $2,775.53 to $2,007.61) for both-component revision. Similarly, for a 2-stage rTHA-I, the mean reimbursement declined by 18.74% ± 3.87% (from $2,063.36 in 2002 to $1,673.36 in 2019) and 24.45% ± 3.69% (from $2,328.79 to $1,755.45) for the explantation and reimplantation stages, respectively. The total decline in physician fee reimbursement for rTHA-I ($1,020.64 ± $233.72) was significantly greater than that for rTHA-A ($580.72 ± $107.22; p < 0.00001).

CONCLUSIONS

Our study demonstrated a consistent devaluation of both rTHA-I and rTHA-A procedures from 2002 to 2019, with a larger deficit seen for rTHA-I. A continuation of this trend could create substantial disincentives for physicians to perform such procedures and limit access to care at the population level.

LEVEL OF EVIDENCE

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

The projected volume of primary and revision total knee arthroplasty will place an immense burden on future health care systems over the next 30 years

PURPOSE

Total knee arthroplasty (TKA) rates have increased substantially in the recent decades worldwide, with Germany being one of the leading countries in the prevalence of TKA. The aim of this study was to provide an overview of treatment changes during the last decade and to project the expected burden of primary and revision TKA (rTKA) for the next 30 years.

METHODS

Comprehensive nationwide data from Germany was used to quantify primary and revision TKA rates as a function of age and gender. Projections were performed with use of a Poisson regression models and a combination of exponential smoothing and autoregressive integrated moving average models on historical procedure rates in relation to official population projections from 2020 to 2050.

RESULTS

The incidence rate of primary TKAs is projected to increase by around 43% to 299 per 100,000 inhabitants [95% CI 231-368], leading to a projected total number of 225,957 primary TKAs in 2050 (95% CI 178,804-276,442). This increase has been related to a growing number of TKA performed in male patients, with the highest increase modelled in patients between 50 and 65 years of age. At the same time, the annual total number of revision procedures is forecast to increase even more rapidly by almost 90%, accounting for 47,313 (95% CI 15,741-78,885; IR = 62.7 per 100,000, 95% CI 20.8-104.5) procedures by 2050. Those numbers are primarily associated with a rising number of rTKAs secondary to periprosthetic joint infection (PJI).

CONCLUSIONS

Using this country- specific forecast approach, a rising number of primary TKA and an even more rapidly growing number of rTKA, especially for PJI, has been projected until 2050, which will inevitably provide a huge challenge for the future health care system. As many other industrialized nations will face similar demographic and procedure-specific developments, these forecasts should be alarming for many health care systems worldwide and emphasize the tremendous need for an appropriate financial and human resource management in the future.

LEVEL OF EVIDENCE

Level III, prognostic study, economic and decision analysis.

Projections and Epidemiology of Revision Hip and Knee Arthroplasty in the United States to 2030

BACKGROUND

As the incidence of primary total joint arthroplasty rises in the United States, it is important to investigate how this will impact rates of revision arthroplasty. The purpose of this study was to analyze the incidence and future projections of revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) to 2030. Anticipating surgical volume will aid surgeons in designing protocols to efficiently and effectively perform rTHA/rTKA.

METHODS

The national inpatient sample was queried from 2002 to 2014 for all rTHA/rTKA. Using previously validated measures, Poisson and linear regression analyses were performed to project annual incidence of rTHA/rTKA to 2030, with subgroup analyses on modes of failure and age.

RESULTS

In 2014, there were 50,220 rTHAs and 72,100 rTKAs. From 2014 to 2030, rTHA incidence is projected to increase by between 43% and 70%, whereas rTKA incidence is projected to increase by between 78% and 182%. The 55-64 and 65-74 age groups increased in revision incidence during the study period, whereas 75-84 age group decreased in incidence. For rTKA, infection and aseptic loosening are the 2 most common modes of failure, whereas periprosthetic fracture and infection are most common for rTHA.

CONCLUSION

The incidence of rTHA/rTKA is projected to increase, particularly in young patients and for infection. Given the known risk factor profiles and advanced costs associated with revision arthroplasty, our projections should encourage institutions to generate revision-specific protocols to promote safe pathways for cost-effective care that is commensurate with current value-based health care trends.

LEVEL OF EVIDENCE

IV.

Burst Release of Antibiotics Combined with Long-Term Release of Silver Targeting Implant-Associated Infections: Design, Characterization and in vitro Evaluation of Novel Implant Hybrid Surface

Implant-associated infections represent a serious risk in human medicine and can lead to complications, revisions and in worst cases, amputations. To target these risks, the objective was to design a hybrid implant surface that allows a local burst release of antibiotics combined with long-term antimicrobial activity based on silver. The efficacy should be generated with simultaneous in vitro cytocompatibility. The investigations were performed on titanium K-wires and plates and gentamicin was selected as an illustrative antibiotic. A gentamicin depot (max 553 µg/cm2) was created on the surface using laser structuring. The antibiotic was released within 15 min in phosphate buffered saline (PBS) or agar medium. Metallic silver particles (4 µg/cm2) in a titanium dioxide layer were deposited using plasma vapor deposition (PVD). About 16% of the silver was released within 28 days in the agar medium. The local efficacy of the incorporated silver was demonstrated in a direct contact assay with a reduction of more than 99.99% (Escherichia coli). The local efficacy of the hybrid surface was confirmed in a zone of inhibition (ZOI) assay using Staphylococcus cohnii. The biocompatibility of the hybrid surface was proven using fibroblasts and osteoblasts as cell systems. The hybrid surface design seems to be promising as treatment of implant-associated infections, considering the achieved amount and release behavior of the active ingredients (gentamicin, silver). The generated in vitro results (efficacy, biocompatibility) proofed the concept. Further in vivo studies will be necessary translate the hybrid surface towards clinical applied research.

One-stage exchange with antibacterial hydrogel coated implants provides similar results to two-stage revision, without the coating, for the treatment of peri-prosthetic infection

PURPOSE

Aim of this study was to verify the hypothesis that a one-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, provides similar infection recurrence rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic joint infection (PJI).

METHODS

In this two-center case-control, study, 22 patients, treated with a one-stage procedure, using implants coated with an antibiotic-loaded hydrogel [defensive antibacterial coating (DAC)], were compared with 22 retrospective matched controls, treated with a two-stage revision procedure, without the coating.

RESULTS

At a mean follow-up of 29.3 ± 5.0 months, two patients (9.1%) in the DAC group showed an infection recurrence, compared to three patients (13.6%) in the two-stage group. Clinical scores were similar between groups, while average hospital stay and antibiotic treatment duration were significantly reduced after one-stage, compared to two-stage (18.9 ± 2.9 versus 35.8 ± 3.4 and 23.5 ± 3.3 versus 53.7 ± 5.6 days, respectively).

CONCLUSIONS

Although in a relatively limited series of patients, our data shows similar infection recurrence rate after one-stage exchange with DAC-coated implants, compared to two-stage revision without coating, with reduced overall hospitalization time and antibiotic treatment duration. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

LEVEL OF EVIDENCE

III.

Cost-effectiveness of timely versus delayed primary total hip replacement in Germany: A social health insurance perspective

Without clinical guideline on the optimal timing for primary total hip replacement (THR), patients often receive the operation with delay. Delaying THR may negatively affect long-term health-related quality of life, but its economic effects are unclear. We evaluated the costs and health benefits of timely primary THR for functionally independent adult patients with end-stage osteoarthritis (OA) compared to non-surgical therapy followed by THR after progression to functional dependence (delayed THR), and non-surgical therapy alone (Medical Therapy), from a German Social Health Insurance (SHI) perspective. Data from hip arthroplasty registers and a systematic review of the published literature were used to populate a tunnel-state modified Markov lifetime model of OA treatment in Germany. A 5% annual discount rate was applied to costs (2013 prices) and health outcomes (Quality Adjusted Life Years, QALY). The expected future average cost of timely THR, delayed THR and medical therapy in women at age 55 were €27,474, €27,083 and €28,263, and QALYs were 20.7, 16.7, and 10.3, respectively. QALY differences were entirely due to health-related quality of life differences. The discounted cost per QALY gained by timely over delayed (median delay of 11 years) THR was €1270 and €1338 in women treated at age 55 and age 65, respectively, and slightly higher than this for men. Timely THR is cost-effective, generating large quality of life benefits for patients at low additional cost to the SHI. With declining healthcare budgets, research is needed to identify the characteristics of those able to benefit the most from timely THR.

The risk factors of failed reimplantation arthroplasty for periprosthetic hip infection

Background

Two-stage reimplantation arthroplasty is one of the standard treatments for chronic periprosthetic joint infection (PJI). Scanty data exist regarding the risk factors for failure after two-stage reimplantation for periprosthetic hip infection. The purpose of this study was to investigate and identify the risk factors associated with failure after two-stage reimplantation hip arthroplasty.

Methods

Sixty-two patients with hip PJI treated with a two-stage reimplantation protocol at our institution from 2005 to 2012 were reviewed. Patients requiring medical treatment or reoperation for recurrent infection were defined as treatment failure. A multivariate Cox proportional hazards model was used to analyze the risk factors associated with treatment failure.

Results

Of the 62 patients, 11 (17.7%) patients had developed reinfection after the two-stage reimplantation with a mean follow-up of 5.7 years. The implant survival was 82.2% (95% confidence interval [CI] 75.19−92.55) at 10 years. Multivariate analysis revealed BMI ≥30 kg/m² (hazard ratio [HR] 9.16; 95% CI 1.51−55.3; p = 0.0158), liver cirrhosis (HR 6.39; 95% CI 1.09−37.4; p = 0.0398), gram-negative organism (HR 5.68; 95% CI 1.18−27.4; p = 0.0303), and presence of sinus tract (HR 18.2; 95% CI 2.15−153; p = 0.0077) as the independent risk factors for treatment failure.

Conclusions

We found obesity, liver cirrhosis, gram-negative organism, and the presence of sinus tract were significantly related to the risks of failure after reimplantation arthroplasties.

Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

BACKGROUND

The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available.

QUESTIONS/PURPOSES

A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department's perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations.

METHODS

A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department's perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes.

RESULTS

Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p <.001). On the level of the separate hospitalizations the mean direct costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p <.001). Major cost drivers were the cost of the implant and general staff. The septic implantation part was on average $3,142.87 more expensive than septic explantations (p <.001).

CONCLUSIONS

Our study for the first time provides a detailed analysis of the major direct case costs of aseptic and septic revision TKA from the hospital-department's perspective which is the basis for long-term orientated decision making. In the future, our cost analysis has to be interpreted in relation to reimbursement estimates. This is important to check whether revision TKA lead to a financial loss for the operating department.

Is it time to rebalance the case mix? A portfolio analysis of direct catheterization laboratory costs over a 5-year period

Background

Cardiac catheterization laboratories (CLL) have continued to function as profit centers for hospitals. Due to a high percentage of material and labor costs, they are natural targets for process improvement. Our study applied a contribution margin (CBM) concept to evaluate costs and cost dynamics over a 5-year period.

Methods

We retrospectively analyzed all procedures performed at a tertiary heart center between 2007 and 2011. Total variable costs, including labor time, material, and maintenance-expenses, were allocated at a global as well as a procedural level. CBM and CBM ratios were calculated by integration of individual DRG revenues.

Results

Annual case volume increased from 1288 to 1545. In parallel, overall profitability improved as indicated by a 2% increase in CBM ratio and a higher CBM generated per hour of CLL working time (4325 vs. 5892 €, p < 0.001). Coronary angiography generated higher average CBMs per hour than coronary or electrophysiological interventions (5831 vs. 3458 vs. 1495 €; p < 0.001). The latter are characterized by relatively high per case material expenditures. On a procedural level, DRG-specific trends as a steady improvement of examination time or an increase in material costs were detectable.

Conclusions

The CBM concept allows a comprehensive analysis of CLL costs and cost dynamics. From a health service providers view, its range of application includes global profitability analysis, portfolio evaluation, and a detailed cost analysis of specific service lines. From a healthcare payers perspective, it may help to monitor hospital activities and to provide a solid data basis in cases where inappropriate developments are suspected. The calculation principle is simple which may increase user acceptance and thus the motivation of team members.

Electronic supplementary material

The online version of this article (doi:10.1186/s40001-016-0238-5) contains supplementary material, which is available to authorized users.