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.

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.