Tourniquet-free minimally invasive total knee arthroplasty is associated with early aseptic loosening.

BACKGROUND

While tourniquet-free (T-) total knee arthroplasty (TKA) has gained popularity, tourniquet-use during minimally-invasive (MIS)-TKA has not been adequately studied. Traditional techniques employ knee hyper-flexion, compressing vasculature and reducing impact of bleeding, while MIS-TKA embraces the semi-extended knee position, which does not restrict the effects of bleeding on cementation and visualization. We compared the risk of aseptic loosening between patients undergoing T- MIS-TKA compared to T + MIS-TKA.

METHODS

This single-surgeon cohort study included 329 consecutive MIS-TKA (226 T+,103 T-) patients with minimum 3-year follow-up. Aseptic loosening, radiolucent lines (RLL), health related quality of life scores, and complications were recorded. T-test and chi-square test were used to compare continuous and categorical variables, and logistic regression included BMI, age, ASA, patellar-resurfacing, and tourniquet-use.

RESULTS

There were no differences in baseline demographics. One (0.4 %) aseptic loosening occurred with T+, versus 7 (6.8 %) with T- (p = 0.002). No T + and 3 T- patients (2.9 %, p = 0.01) had revision for aseptic loosening. The incidence of RLLs was 16.8 % in T + and 30.1 % in T- (p = 0.008). Logistic regression revealed T + was significantly associated with decreased aseptic loosening and risk of RLL (odds ratio = 16.4, odds ratio = 2.8).

CONCLUSION

In this consecutive series, T- MIS-TKA was associated with increased rates of revision for aseptic loosening as compared to the T + MIS-TKA, even controlling for BMI, age, ASA level, and patellar resurfacing. Radiolucent lines were increased with T- MIS-TKA compared to T + MIS-TKA. Complications, all-cause revision, ROM, and HRQoL scores were similar between tourniquet-use and tourniquet-free cohorts.