Increased Early Mortality in Bilateral Simultaneous TKA Using Conventional Instrumentation Compared with Technology-Assisted Surgery: A Study of 34,908 Procedures from a National Registry

No Difference in 30-day Mortality Between Patients Undergoing Bilateral Simultaneous Total Knee Arthroplasty With Technology Assistance Compared to Conventional Instrumentation

Background: Bilateral simultaneous total knee arthroplasty (BSTKA) has decreased in frequency due to concerns about higher rates of early mortality and complications than unilateral or staged surgeries. Purpose: We sought to evaluate whether technology assistance (encompassing robotics and computer assistance) decreases early mortality following BSTKA. Methods: We conducted a retrospective cohort study using a national all-payer claims database. Patients who underwent BSTKA from October 2015 to December 2020 were identified. Univariate and multivariable analyses were conducted to compare outcomes in patients who underwent BSTKA with technology assistance compared to conventional instrumentation. The primary outcome was 30-day postoperative mortality. Secondary outcomes were respiratory failure and fat embolism. A post-hoc analysis was performed to evaluate length of stay, readmission, and other medical complications. Results: A total of 14,870 patients who underwent BSTKA were included in this study. Of these, 860 patients underwent technology-assisted BSTKA, and 14,010 patients underwent BSTKA without technology assistance. After a multivariable analysis, patients who underwent technology-assisted BSTKA had equivalent odds of 30-day mortality compared to those who underwent BSTKA without technology assistance. Technology assistance was not protective against the development of acute respiratory failure or fat embolism. Conclusion: This retrospective cohort study found no differences in the rates of 30-day mortality, respiratory failure, or fat embolism after technology-assisted BSTKA compared to conventional BSTKA. On the post-hoc analysis, technology use was associated with a decreased length of stay, lower readmission risk, and decreased rates of deep vein thrombosis, pulmonary embolism, and blood transfusion.

Improving alignment in total knee arthroplasty: a cadaveric assessment of a surgical navigation tool with computed tomography imaging

PURPOSE

To investigate the accuracy of an imageless, optical surgical navigation tool to assist with femoral and tibial bone cuts performed during TKA.

PATIENTS AND METHODS

Six board-certified orthopedic surgeons participated in a laboratory cadaver investigation, performing femoral and tibial bone cuts with the assistance of a computer navigation tool. Femoral and tibial varus/valgus, tibial slope, femoral flexion, and both femoral and tibial rotation measurements from the device were compared with angular measurements calculated from computed tomography (CT) images of the knees.

RESULTS

Measurements with the navigation tool were highly correlated with those obtained from CT scans in all three axes. For the distal femoral cut, the absolute mean difference in varus/valgus was 0.83° (SD 0.46°, r = 0.76), femoral flexion was 1.91° (SD 1.16°, r = 0.85), and femoral rotation was 1.29° (SD 1.01°, r = 0.88) relative to Whiteside's line and 0.97° (SD 0.56°, r = 0.81) relative to the posterior condylar axis. For the tibia, the absolute mean difference in varus/valgus was 1.08° (SD 0.64°, r = 0.85), posterior slope was 2.78° (SD 1.40°, r = 0.60), and rotation relative to the anteroposterior axis (posterior cruciate ligament to the medial third of the tibial tuberosity) was 2.98° (SD 2.54°, r = 0.79).

CONCLUSION

Utilization of an imageless navigation tool may aid surgeons in accurately performing and monitoring femoral and tibial bone cuts, and implant rotation in TKA and thus, more accurately align TKA components.

Bilateral Total Knee Arthroplasty: Current Concepts Review

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Bilateral total knee arthroplasty (BTKA) is an effective surgical treatment for bilateral knee arthritis and can be performed as a simultaneous surgery under a single anesthetic setting or as staged surgeries on separate days.

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Appropriate patient selection is important for simultaneous BTKA with several factors coming into consideration such as age, comorbidities, work status, and home support, among others.

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While simultaneous BTKA is safe when performed on appropriately selected patients, current evidence suggests that the risk of complications after simultaneous BTKA remains higher than for staged BTKA.

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When staged surgery is preferred, current evidence indicates that complication risks are minimized if the 2 knees are staged at least 3 months apart.

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Simultaneous BTKA is the economically advantageous treatment option relative to staged BTKA, primarily because of shorter total operative time and total hospital stay.

Increased early mortality after total knee arthroplasty using conventional instrumentation compared with technology-assisted surgery: an analysis of linked national registry data

OBJECTIVES

This study aims to compare early mortality after total knee arthroplasty (TKA) using conventional intramedullary instrumentation to TKA performed using technology-assisted (non-intramedullary) instrumentation.

DESIGN

Comparative observational study. Using data from a large national registry, the 30-day mortality after unilateral TKA performed for osteoarthritis was compared between procedures using conventional instrumentation and those using technology-assisted instrumentation. Firth logistic regression was used to calculate ORs, adjusting for age, sex, use of cement and procedure year for the whole period, and additionally adjusting for American Society of Anesthesiologists physical status classification system class and body mass index (BMI) for the period 2015 to 2019. This analysis was repeated for 7-day and 90-day mortality.

SETTING

National arthroplasty registry.

PARTICIPANTS

People undergoing unilateral, elective TKA for osteoarthritis from 2003 to 2019 inclusive.

INTERVENTIONS

TKA performed using conventional intramedullary instrumentation or technology-assisted instrumentation.

MAIN OUTCOME MEASURES

30-day mortality (primary), and 7-day and 90-day mortality.

RESULTS

A total of 581 818 unilateral TKA procedures performed for osteoarthritis were included, of which 602 (0.10%) died within 30 days of surgery. The OR of death within 30 days following TKA performed with conventional instrumentation compared with technology-assisted instrumentation, adjusted for age, sex, cement use, procedure year, American Society of Anesthesiologists and BMI was 1.72 (95% CI, 1.23 to 2.41, p=0.001). The corresponding ORs for 7-day and 90-day mortality were 2.21 (96% CI, 1.34 to 3.66, p=0.002) and 1.35 (95% CI, 1.07 to 1.69, p=0.010), respectively.

CONCLUSIONS

The use of conventional instrumentation during TKA is associated with higher odds of early postoperative death than when technology-assisted instrumentation is used. This difference may be explained by complications related to fat embolism secondary to intramedullary rods used in conventional instrumentation. Given the high number of TKA performed annually worldwide, increasing the use of technology-assisted instrumentation may reduce early post-operative mortality.