Introduction: The aim of this study was to compare the functional outcome between the first and second knee replacement in patients undergoing staged bilateral total knee arthroplasty.
Methods: We identified 64 patients who had bilateral knee replacements and had at least one year of postoperative outcome studies. Data on pain scores, walking ability, use of walking aids, range of movement, instability, muscle strength, WOMAC® (Western Ontario and McMaster Universities) scores, SF-12 (Short Form 12) scores, American Knee Society radiological scores and length of hospital stay (LOS) were recorded. The difference in data between the first and second knee was assessed.
Results: Groups remained statistically comparable between the first and second operation. Four outcomes showed a significant difference between the second and first knee. The mean score for postoperative walking ability was 4.83 (second knee) vs 4.51 (first knee) (p =0.03). The mean score for postoperative walking aid requirement was 5.73 (second knee) vs 5.46 (first knee) (p=0.01). The mean postoperative SF-12 score was 54.26 (second knee) vs 52.45 (first knee) (p=0.04). The mean LOS was 4.73 days (second knee) vs 6.16 days (first knee) (p =0.05). All other data comparisons were statistically insignificant.
Conclusions: Patients have a reduced LOS and continue to improve after the second procedure with regards to walking ability, use of walking aids and psychological wellbeing.