Fast-Track Bilateral Simultaneous Total Knee Arthroplasty: How's That Working?

Studies conflict regarding the safety of bilateral simultaneous total knee arthroplasty (BSTKA). Some show high risk of postoperative complications and mortality compared to staged procedures, while others report that BSTKA is as safe as staged procedures.

A retrospective single-center study examined BSTKA patients in a modern, fast-track setting and looked at early morbidity and mortality, factors for re-admission within 90 days, and for a length of stay (LOS) of greater than 5 days. The results were published in the January 2016 issue of Acta Orthopaedica.

The researchers selected 284 patients who presented with painful bilateral knee osteoarthritis. Patients had no known cardiopulmonary comorbidity and underwent BSTKA at the authors’ institution. (The fast-track setup was described in an earlier paper; it involves combining evidence-based, clinical features with organizational optimization including a revision of traditions.) All surgeries occurred between 2008 and 2014 and were preformed by a consultant specialized in joint replacement surgery. The median age was 65 years (33-86 years old), 53% of patients were female (150/284), mean BMI was 30 (19-50), 26% of the patients has an ASA score of 1, 68% has an ASA score of 2, and 6% had an ASA score of 3.

After surgery, patients were transferred to the postoperative recovery unit, where immediate mobilization was attempted. Attending surgeons delayed patient discharge until patients met certain functional criteria (e.g., walking 70 meter with or without crutches).

The authors report 90-day mortality was 0% (perhaps, the researchers reason, because the fast-track process chooses the best surgical candidates), and 8% of patients were re-admitted within 30 days (this increased to 10% within 90 days). Patients with ASA scores of 3 were more likely to be readmitted than those with lower scores.

Re-admission times ranged from 18-75 days (the median was 18 days). Patients were most often re-admitted for surgical site infection (treated with antibiotics alone n = 2, and with revision n = 6). The median length of stay was 3 days (2-30 days with 14% of patients staying longer than 5 days).

The authors concluded that their results are “encouraging” and mirror other studies that have examined postoperative mortality for BSTKA procedures in fast-track settings. The researchers also noted that their readmission rates (8% within 30 days, 10% within 90 days), the reason for re-admission (infection), and length of stay all were similar to other studies.

The authors concluded that BSTKA in a fast-track setting and performed on patients without cardio-pulmonary disease seems to be safe with respect to postoperative morbidity and mortality.