# Learning Curve in Robotic-Assisted Total Knee Arthroplasty: A Systematic Review of the Literature
## 4 Discussion
[24] observed no difference in the mean surgical time for the last ten raTKA and mTKA cases. Similarly, no surgical time differences were reported both either [PERSON] et al. [28] or [PERSON] et al. [32] in the last cases of raTKA compared to mTKA. The robots and the implants used differ, so improvements may be found at different surgery phases [39; 41; 42; 43]. [PERSON] et al. [33] reported that the most remarkable improvement was observed in robot setup (from 14.8 min to 9.2 min), bone registration (from 15.8 min to 11.5 min), bone preparation (from 15.8 min to 11.1 min), and joint balancing (from 14.3 min to 9 min). In contrast, no significant improvement was observed in surgical steps, such as surgical approach, implant trial, cement implantation, and closure. Conversely, different data were reported by [PERSON] et al. [23] that noted a significant improvement not only in robotic setup (from 8.9 min to 7.3 min), bone registration (from 103 min to 7.5 min), and joint balancing (from 7 min to 4.1 min) but also for implant trialing (from 17.3 min to 13.5 min). At the same time, no significant improvement was noted for the surgical approach and bone preparation phases. [PERSON] et al. [27] reported a \"dramatic increase in efficiency\" during the review of the intraoperative phase, in which the surgeon reviews the bone cuts suggested by the robot. Appropriate component placement in TKA has a crucial role in improving clinical outcomes and patient satisfaction [7; 13; 14]. Inadequate implant positioning leads to increased polyethylene wear due to higher contact forces and inappropriate soft tissue tension, reducing implant survival [3; 5; 39]. Some authors have hypothesized that implant malignant may reduce postoperative satisfaction because of proprioception changes [1; 44; 45]. Based on this systematic review, most studies did not report an evident learning curve for component positioning accuracy [25; 26; 27; 28; 29]. In their paper, [PERSON] et al. [21] observed a significantly high rate of misaligned components during the raTKA learning phase compared to the proficiency phase. Furthermore, the authors found no statistically significant differences between intraoperative measurement and postoperative values [21]. On the contrary, [PERSON] et al. [25] reported a statistically significant difference between intraoperative and postoperative valuation, and [PERSON] et al. [29] described a mean postoperative HKA of 1.2\({}^{\circ}\) more valgus than for intraoperative. [PERSON] et al. [24] showed improved accuracy for HKA, femoral sagittal inclination, and tibial coronal inclination in raTKA. [PERSON] et al. [23] reported better accuracy for HKA, femoral coronal and sagittal alignment, tibial coronal and sagittal alignment, and tibial slope in raTKA. In contrast, [PERSON] et al. [32] found no statistically significant differences between patients undergoing mTKA and raTKA. The studies included in this systematic review reported complications both related and unrelated to robotic-assisted surgery. [PERSON] et al. [29] described persistent tibial pain at the pin placement site. Further inspections revealed a tibial diaphysseal stress fracture caused by the registration pin insertion. The fracture healed without complications in eight weeks. [PERSON] et al. [26] reported the persistence of a pin metal fragment in the distal femur that did not result in further complications. [PERSON] et al. [23] described a case of arthofibrosis during both the learning and proficiency curve phases. Additional complications not directly related to robotic-assisted surgery, such as patellar tendon rupture, arthofibrosis, tibial fracture, surgical wound dehiscence, deep vein thrombosis, and pulmonary embolism, are also described in the studies included in this systematic review [21; 23; 28; 31]. Ra surgery could simplify and minimize the instrumentation needed to perform surgical procedures, significantly reducing instrumentation sterilization and storage costs.