Functional outcome after computer-assisted total knee arthroplasty using measured resection versus gap balancing techniques: a randomised controlled study

Purpose. To compare the 2-year outcome of total knee arthroplasty (TKA) using the measured resection versus the gap balancing techniques. Methods. 21 men and 31 women aged 41 to 89 (mean, 73) years who underwent primary TKA by a single surgeon for osteoarthritis and had an American Society of Anesthesiologists I or II physical status were prospectively studied. Patients were randomised to undergo computer-assisted TKA using the measured resection technique (n= 26) or the gap balancing technique (n= 26). At the 2-year followup, patients were assessed by a single orthopaedic registrar blinded to the type of surgery using the Knee Society score (KSS), functional Knee Society score (FKSS), and revised Oxford Knee score (ROKS). Results. In the measured resection group, the mean KSS, FKSS, and ROKS increased from 34.3, 48, and 21 to 85.9, 89.6, and 36.5, respectively. In the gap balancing group, the respective scores increased from 35.4, 50, and 22.5 to 89.1, 92.4, and 40.6. Postoperative increases in the respective scores were slightly better with the gap balancing technique; the respective p values were 0.46, 0.44, and 0.12. Conclusion. Improvements in the knee scores were comparable with the 2 techniques.