Length of stay after introduction of a new total knee arthroplasty (TKA)—results of a German retrospective database analysis

Abstract

Background

Although total knee arthroplasty (TKA) procedures are increasing, patient satisfaction is still inferior compared to total hip arthroplasty. The ATTUNE^® Knee System was designed to reduce pain and improve function, leading to greater patient satisfaction and decreased resource utilization in TKA. The objective of this study was to compare length of stay (LOS) of TKA with ATTUNE knee versus LCS^® knee implants.

Methods

A retrospective chart review analysis in a German center was conducted between 2008 and 2016. All patients without prior ipsilateral knee operation, treated with a cemented LCS or ATTUNE knee were included. Endpoints captured included gender, age, availability of home support, prior contralateral TKA, ASA grade and LOS. Statistical analyses included chi-squared test for differences in patient demographics and Welch two-sample t-test for difference in LOS.

Results

Mean LOS in the ATTUNE Knee group (N=85) was 8.3 days (SD: 1.79) compared to 10.4 days (SD: 1.91) in the LCS knee group (N=85). No significant differences in gender, age, availability of home support, prior contralateral TKA, or ASA grade between both cohorts were observed. The 2.1 days reduction was statistically significant (P<0.001; 95%CI: 2.7–1.6). A sensitivity analysis outlined the impact of the study duration: even when assuming that 1.3 days reduction resulted from the observed national LOS decrease, the remaining 0.8 reduction in days LOS reduction was still significant (P<0.01).

Conclusion

When comparing two cohorts with similar sociodemographic and medical factors, LOS of ATTUNE knee patients was 2.1 days shorter than patients treated with the LCS knee.

Keywords:

• total knee arthroplasty
• ATTUNE Knee System
• length of stay
• Germany

Acknowledgments

The authors thank Johnson & Johnson for an unrestricted grant for data analysis, data extraction and publication.

Disclosure

Prof. Dr B Brüggenjürgen reports grants from J&J Medical, during the conduct of the study. Dr C Mühlendyck is an employee of Johnson and Johnson Medical, Germany.  Mrs LV Gador is an employee of Johnson and Johnson Medical, Germany. Prof. Dr A Katzer reports no conflicts of interest in this work.

This paper/the abstract of this paper was presented at:

1. ISPOR Europe 2017 as a poster presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in Value in Health 20 (2017) A399–A811: https://www.valueinhealthjournal.com/article/S1098-3015(17)31460-2/abstract.

2. Endoprothetikkongress Berlin, 22–24.02.2018, as a poster presentation with interim findings.