Bone Cement Waste in Total Knee Arthroplasty: A Preliminary Study of Scope and Cost.

Background: Medical waste is both costly and detrimental to the environment, and operating room waste represents a substantial portion of this. To the authors' knowledge, bone cement waste in total knee arthroplasty (TKA) has not previously been studied. The vast majority of TKA are cemented, and the volume of TKA is forecast to increase. Given this, we studied the waste resulting from the routine use of 2 40-gram bags of polymethyl methacrylate (PMMA) powder during cementing in primary TKA. Methods: We first studied the yield of commercially available plain and gentamicin medium-viscosity bone cement powder and calculated the cost/gram of product. We then collected the PMMA remaining after primary TKA to determine the average amount of waste, its cost, and possible correlations with patient and implant metrics that could improve efficiency and reduce waste of PMMA. Results: Overall, PMMA waste averaged 59% per TKA, at a median cost of $129 per case. Cost of waste was greater when gentamicin cement was used, as its cost was 2.5X that of plain cement. Implant sizes and surface area ranges were identified that could reliably allow the use of a single 40-gram package of powder, potentially reducing PMMA waste. Conclusions: While it is acknowledged that zero-waste cementing is not practical, any reduction in waste that does not compromise either the flow of surgery or the adequacy of fixation would be beneficial. Reevaluation of PMMA techniques could reduce waste, resulting in both cost savings and improved sustainability in arthroplasty.

Registry Data Show Complication Rates and Cost in Revision Hip Arthroplasty.

BACKGROUND: Revision total hip arthroplaty (rTHA) places a burden on patients, surgeons, and health care systems because outcomes and costs are less predictable than primary THA. The purpose of this study was to define indications and treatments for rTHA, quantify risk for readmissions, and evaluate the economic impacts of rTHA in a hospital system. METHODS: The arthroplasty database of a hospital system was queried to generate a retrospective cohort of 793 rTHA procedures, performed on 518 patients, from 2017 to 2019 at 27 hospitals. Surgeons performed chart reviews to classify indication and revision procedure. Demographics, lengths of stay, discharge dispositions, and readmission data were collected. Analyses of direct costs were performed and categorized by revision type. RESULTS: Totally, 46.3% of patients presented for infection. Patients presenting for infection were 5.6 times more likely to have repeat rTHA than aseptic patients. Septic cases (4.3 days) had longer length of stay than aseptic ones (2.4) (P < .0001). However, 31% of patients discharged to a skilled nursing facility. Direct costs were greatest for a two-stage exchange ($37,642) and lowest for liner revision ($8,979). Septic revisions ($17,696) cost more than aseptic revisions ($11,204) (P < .0001). The 90-day readmission rate was 21.8%. Septic revisions had more readmissions (13.5%) than aseptic revisions (8.3%). CONCLUSIONS: Hip revisions, especially for infection, have an increased risk profile and create a major economic impact on hospital systems. Surgeons may use these data to counsel patients on risks of rTHA and advocate for improved reimbursement for the care of revision patients.

The Economic Impact of Lower Extremity Periprosthetic Fractures in a Large Hospital System.

BACKGROUND: Periprosthetic fractures (PPFs) place a burden on hospital systems. They occur in older patients with medical comorbidities, as unplanned events requiring technically complex surgeries with expensive implants. The purpose of this study was to describe this patient population and evaluate the economic impact of PPFs on a hospital system. METHODS: We conducted a retrospective study of PPFs of the hip and knee between 2018 and 2019. Demographics, length of stay (LOS), and discharge disposition were collected. We performed chart and radiographic reviews to determine the fracture classification and type of treatment performed. An analysis of direct inpatient costs was performed and categorized by a fracture type. RESULTS: We identified 213 periprosthetic hip and 151 periprosthetic knee fractures. The mean age of hip patients was 77 years, and 71% were female. The average surgery time was 194 minutes, LOS was 5.01 days, and 71% were discharged to a skilled nursing facility (SNF). The mean age of knee patients was 76 years, and 79% were female. The average surgery time was 174 minutes, LOS was 5.12 days, and 70% were discharged to a SNF. The median direct cost of hip fractures was $17,108, with Vancouver B2 and B3 costing significantly more at $19,987 and $23,935, respectively (P value <.0001). The median direct cost of knee fractures was $13,713. Type 3 distal femur fractures cost significantly more at $37,445 (P value <.0001). CONCLUSION: PPFs create a significant economic impact on hospital systems. We stratified the costs of treatment based on the fracture type. Significantly higher costs are associated with injuries requiring revision implants.

Robotic Versus Manual Total Knee Arthroplasty in High Volume Surgeons: A Comparison of Cost and Quality Metrics.

BACKGROUND: Robotic-assisted total knee arthroplasty (RTKA) was introduced to improve surgical accuracy and patient outcomes. However, RTKA may also increase operating time and add cost to TKA. This study sought to compare the differences in cost and quality measures between manual TKA (MTKA) and RTKA METHODS: All MTKAs and RTKAs performed between January 1, 2017 and December 31, 2019, by 6 high volume surgeons in each cohort, were retrospectively reviewed. Cohorts were propensity score matched. Operative time, length of stay (LOS), total direct cost, 90-day complications, utilization of postacute services, and 30-day readmissions were studied. RESULTS: After one-to-one matching, 2392 MTKAs and 2392 RTKAs were studied. In-room/out-of-room operating time was longer for RTKA (139 minutes) than for MTKA (107 minutes) P < .0001, as was procedure time (RTKA 78 minutes; MTKA 70 minutes), P < .0001. Median LOS was equal for MTKA and RTKA (33 hours). Total cost per case was greater for RTKA ($11,615) than MTKA ($8674), P < .0001. Home health care was utilized more frequently after RTKA (38%) than MTKA (29%), P < .0001. There was no significant difference in 90-day complication rates. Thirty-day readmissions occurred more often after MTKA (4.9%) than RTKA (1.2%), P < .0001. CONCLUSION: RTKA was a longer and costlier procedure than MTKA for experienced surgeons, without clinically significant differences in LOS or complications. Home health care was utilized more often after RTKA, but fewer readmissions occurred after RTKA. Longer term follow-up and functional outcome studies are required to determine if the greater cost of RTKA is offset by lower revision rates and/or improved functional results.

Can a Reduction in Revision Rates Make Robotic Total Knee Arthroplasty Cost Neutral With Manual Total Knee Arthroplasty at Ten-Year Follow-Up? An Episode Cost Analysis.

BACKGROUND: Advocates of robotic total knee arthroplasty (RTKA) suggest that its greater cost may be recaptured through a reduction in revision rates. We sought to determine what reduction in revision TKA would be required for RTKA to become cost neutral with manual TKA (MTKA). METHODS: Episode costs were determined for 2392 RTKAs and 2392 MTKAs. Mean total cost of revision TKA in our health system was identified. Episode cost difference of the RTKA and MTKA cohorts was divided by the mean cost of revision TKA to estimate the reduction in revisions required to make RTKA cost neutral with MTKA. The National Joint Registry was consulted to determine the cumulative revision rate for the implant used in this study. RESULTS: Episode cost for the RTKA cohort was $5.7M greater than MTKA. Mean acute stay cost for revision TKA was $20,972, but post-acute costs were not available. If post-acute costs for revision TKA are conservatively estimated at 50% of episode cost (ie, episode cost = $41,944), 131 revision TKAs would need to be prevented in the RTKA cohort to make it cost neutral with MTKA. The National Joint Registry cumulative revision rate for this implant is 3.37% at 10 years, thus only 81 revisions would be expected per cohort. CONCLUSION: Our data suggest that it is not possible for RTKA to achieve cost parity with MTKA through a reduction in revision rate alone. Future price reductions may make the cost comparison more favorable. In addition, demonstration of improved patient outcomes would undeniably add value to RTKA and change the analysis.

Extremes of body mass index have significant impact on complications, readmissions, and utilization of post-acute services after primary total hip arthroplasty.

AIMS: High body mass index (BMI) is associated with increased rates of complications in primary total hip arthroplasty (THA), but less is known about its impact on cost. The effects of low BMI on outcomes and cost are less understood. This study evaluated the relationship between BMI, inpatient costs, complications, readmissions, and utilization of post-acute services. METHODS: A retrospective database analysis of 40,913 primary THAs performed between January 2013 and December 2017 in 29 hospitals was conducted. Operating time, length of stay (LOS), complication rate, 30-day readmission rate, inpatient cost, and utilization of post-acute services were measured and compared in relation to patient BMI. RESULTS: Mean operating time increased with BMI and for BMI > 50 kg/m2 was approximately twice that of BMI 10 kg/m2 to 15 kg/m2. Mean inpatient cost did not vary significantly with BMI. Mean total reimbursement was lowest for the lowest BMI cohort and increased with BMI. Mean LOS was greatest at the extremes of BMI (4.0 days for BMI 10 kg/m2 to 15 kg/m2; 3.75 days for BMI > 50 kg/m2) and twice that of normal BMI. Mean complication rates were greatest in the lowest BMI cohort (16% for BMI 10 kg/m2 to 15 kg/m2) and five times the mean rate of complications in the normal BMI cohorts. Furthermore, 30-day readmissions were greatest in the highest BMI cohort (10% for BMI > 50 kg/m2) and five times the rate for normal BMI patients. CONCLUSION: LOS, complications, and 30-day readmissions all increase at the extremes of BMI and appear to be greater than those of patients with normal BMI. The lowest BMI patients had the lowest payment for inpatient stay yet were at considerable risk for complications and readmission. Patients with extreme BMI should be counselled about their increased risk of complications for THA and nutritional status/obesity optimized preoperatively if possible. Cite this article: Bone Joint J 2020;102-B(7 Supple B):62-70.