The learning curve of MAKO-assisted total knee arthroplasty / 中华骨科杂志

ABSTRACT

Objective:To explore the learning curve of MAKO-assisted total knee arthroplasty.Methods:From May 2021 to September 2022, 136 patients were conducted MAKO-assisted total knee arthroplasty in the PLA General Hospital, including 37 males and 99 females, 65.53±7.01 years old (range 54-80 years). All cases were patients with unilateral knee osteoarthritis. The operations were performed by three surgeons, respectively. Sixty-one cases were performed by surgeon 1, 47 cases were performed by surgeon 2, and 28 cases were performed by surgeon 3. Record the time of each step during the operation, and measure the limb alignment in X-ray. The statistical difference between the two groups was compared by t test by SPSS. The cumulative sum control chart (CUSUM) learning curve was modeled by curve fitting and R2 was used to testify the goodness. Results:The total operation time of the three surgeons was 114.3±25.1 min, 109.8±10.9 min, and 118.6±15.1 min, respectively. The time of each step in the first 10 cases and the last 10 cases of operator 1-3 was counted. The osteotomy time of surgeons 1, 2 and 3 in the final 10 cases was less than that in the initial 10 cases (surgeon 1 13.5 ± 3.41 min vs. 8.0±1.58 min, t=4.30, P=0.001; surgeon 2 13.7±3.02 min vs. 8.0± 2.58 min, t=4.77, P=0.001; surgeon 3 15.3±3.97 min vs. 11.0±2.38 min, t=2.87, P=0.010), and the difference was statistically significant. The CUSUM of osteotomy was calculated and the curve was fitted. The highest point of the curve of the three surgeons was in the 16th, 18th and 12th patients, respectively, and the time of osteotomy continued to decline after passing the peak. No statistical differences were found in surgery time for the remaining steps. Comparing the lower alignment angles of intraoperative planning and postoperative X-ray films, the overall difference was greater than 1 degree. The difference was 1.41°±1.32° for operator 1, 1.34°±1.22° for operator 2, and 1.04°±0.88° for operator 3. The percentages of fully accurate implant size planning were 85.2%(52/61), 76.7%(36/47), and 85.7%(24/28), respectively. Conclusion:For MAKO-assisted total knee arthroplasty, the operator can decrease the operation time by practice, which is mainly reflected in the shortening of the osteotomy time. The learning curve threshold is around in the 15th case. The increase in the number of surgeries did not bring about changes in the accuracy of lower extremity alignment.