Learning curve of a robotic knee system in total knee arthroplasty

Robotically assisted knee arthroplasty (rTKA) is more time consuming, with a more extended learning curve than manual knee arthroplasty (mTKA). Our study aimed to estimate the learning curve of an experienced orthopaedic surgeon to achieve comparable mean operative time between rTKA and mTKA and we also compaired the early complications. The prospective comparative study included 150 Persona PS rTKA and 150 Evolution medial pivot mTKA. The surgeries were performed consecutively by 3 senior surgeons, 50 rTKN and 50 mTKA for each surgeon, between January 2023 and August 2025 and we compaired the operative time and the complications related to surgery between the 2 groups for each surgeon to establish the learning curve for knee robotic surgery. The consecutive cases in each group were divided in ten sugroups, each of 10 cases. The groups were compaired concerning age, sex, BMI and Kellgren-Lawrence classification. The first non-significant difference between the mTKAs and rTKAs operative times was observed in the subgroup of 30 to 40 cases. Till then, the operative time has been significantly lower for mTKA than the rTKA group of cases. The group of ten cases between 30 and 40 showed no operative time differences for all the surgeons. The learning curve analysis demonstrated that the surgeon becomes used and comfortable with surgery technique from case 33 onwards. Both groups had no differences regarding the complications rates. The study showed that about 30 cases are needed for a senior surgeon to balance operative time between mTKA and rTKA using the ROSA system.