Robotic Guided Knee Arthroplasty - Group Learning Curve and Early Outcomes

Previous studies have reported initial and proficiency phases of the learning curve among individual surgeons when robotic-assisted total knee arthroplasty (raTKA) into their practices. The purpose of this study was to assess the number of raTKA cases needed to achieve proficiency in the operative time (OT) across a group of surgeons.

A retrospective analysis comparing raTKA to manual Total Knee Arthroplasty (mTKA) was performed at a single-site comprised of 6 orthopaedic surgeons. The first 90 patients who underwent raTKA at the institution divided chronologically into 3 groups of 30 each and compared to 30 previous mTKA cases. Tourniquet time was used as the measure for OT, range of motion (ROM) was measured preoperatively and at 2 and 6 weeks postoperative.

Average OT was significantly shorter in the mTKA group in comparison with all the raTKA groups. A statistically significant difference was found in OT when comparing the succeeding raTKA groups (mean time of 97.6, 86.6, and 76.7 min P value<.001). The change in ROM at 6 weeks postoperative was found to be greater in the first raTKA group in comparison to the second raTKA group (mean of 0.9° vs -17.1°; P = .04) and the mTKA group (mean of 0.9° vs -7.9°; P = .04). However, when controlling for preoperative ROM and performing surgeon, there was no difference in ROM at 6 weeks postoperative between defined time periods (P = .78). No difference was found when comparing rate of complications (P value>.05).

When evaluating the group learning curve, this study showed average shorter operating time with every 30 cases (mean time of 97.6; 86.6- and 76.7-min P value<.001) and no difference in complication rate (P value>.05). These findings suggest continued proficiency over time; however, adoption of the technology is associated with longer OTs.