OBJECTIVES: Total Knee Arthroplasty (TKA) is increasingly performed and novel designs need to address clinical improvements and cost savings. It was hypothesized that a new knee system – the Attune knee – may result in reduced length of stay (LOS). This study was thus conducted in a real-world setting in a German private clinic to determine LOS of patients with Attune vs LCS implants.

METHODS: A retrospective chart review from July 2008 to June 2016 was conducted and included all consecutive patients treated with LCS (from July 2008 to October 2013) and Attune (from November 2013 to June 2016). No organizational change took place during the study period and all patients were treated by the same surgical team. Data capture for all patients included sex, age group (41-50, 51-60, 61-70, 71-80), availability of home support, prior contralateral TKA, ASA score and length of stay. Statistical analyses included chi-squared test for differences in patient demographics and presentation, and difference in LOS was evaluated using an ANOVA test.

RESULTS: A total of 170 consecutive patients were included (85 Attune, 85 LCS), age distribution included 5%, 13%, 30%, 44% and 8% patients in the 41-50, 51-60, 61-70, 71-80 and >80 years age categories, respectively. 18% of patients had previous TKA in the contralateral knee, 68% had support at home and 56% were ASA Grade 3 at time of surgery. There were no significant differences in any of these variables between Attune and LCS cohorts. However, average LOS was significantly lower in the Attune group, from average 10.4 (SD:1.91) for the LCS group to 8.3 (SD:1.79) in the Attune cohort (p<0.001), a difference of 2.1 days (95% CI 2.7 - 1.6).

CONCLUSIONS: Comparing two cohorts with similar demographic factors, patients implanted with Attune had a LOS on average 2.1 days shorter than patients treated with LCS.