{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T15:20:50Z","timestamp":1773415250559,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T00:00:00Z","timestamp":1773360000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Learning curves robotic arm-assisted total knee arthroplasty (TKA) are well-documented for semi-active systems, but evidence for advanced fully active robotic systems remains scarce. This study aimed to characterize the learning curve for operative time, implant positioning, and lower-limb alignment using a fully active robotic TKA system, specifically accounting for the impact of rotating resident involvement in a tertiary center. Materials and Methods: Sixty consecutive primary TKAs were performed using the advanced active robotic system (CUVIS-Joint\u00ae). The learning curve for operative time was evaluated using cumulative summation (CUSUM) analysis. To identify independent predictors of surgical duration and radiographic precision, a multivariate linear regression model was constructed, including case number, implant type, and resident rotation period as variables. Results: CUSUM analysis identified a statistically significant inflection point at the 39th case. Beyond this point, mean operative time decreased approximately 20 min (133.3 \u00b1 13.5 vs. 113.8 \u00b1 7.9 min, p &lt; 0.001). Multivariate regression confirmed that case number was the sole independent predictor of operative time (p &lt; 0.001). Notably, implant positioning and lower-limb alignment showed no detectable difference across the sequential cases (p &gt; 0.05), maintaining high precision from the outset. Conclusions: Active robotic TKA demonstrated a learning curve for operative time that stabilized after 39 cases within a clinical setting of rotational resident participation. Radiographic accuracy remained consistent despite these educational requirements, supporting the technical feasibility and reliability of this advanced system for the management of end-stage knee osteoarthritis<\/jats:p>","DOI":"10.3390\/medicina62030533","type":"journal-article","created":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T11:12:25Z","timestamp":1773400345000},"page":"533","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Does Resident Rotation Affect the Learning Curve of Active Robotic TKA? A Study of Surgical Efficiency and Radiographic Precision"],"prefix":"10.3390","volume":"62","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3741-2311","authenticated-orcid":false,"given":"Yong-Beom","family":"Park","sequence":"first","affiliation":[{"name":"Department of Orthopedic Surgery, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, Gwangmyeong-si 14353, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jin-Woong","family":"Jeon","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Seong Hwan","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Han-Jun","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06973, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1186\/s43019-021-00125-z","article-title":"The use of imageless navigation to quantify cutting error in total knee arthroplasty","volume":"33","author":"Schwarzkopf","year":"2021","journal-title":"Knee Surg. Relat. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1186\/s43019-022-00143-5","article-title":"A comparison of utilization and short-term complications of technology-assisted versus conventional total knee arthroplasty","volume":"34","author":"Simcox","year":"2022","journal-title":"Knee Surg. Relat. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"82","DOI":"10.4055\/cios21138","article-title":"No Difference in Clinical Outcomes and Survivorship for Robotic, Navigational, and Conventional Primary Total Knee Arthroplasty with a Minimum Follow-up of 10 Years","volume":"15","author":"Lee","year":"2023","journal-title":"Clin. Orthop. Surg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"425","DOI":"10.4055\/cios22289","article-title":"The Usefulness of a Simplified Navigation-Based Instrumentation for a Novice Surgeon in Primary Total Knee Arthroplasty: A Retrospective Analysis of a Randomized Controlled Trial","volume":"15","author":"Shon","year":"2023","journal-title":"Clin. Orthop. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3854","DOI":"10.1016\/j.arth.2017.07.021","article-title":"Patient Dissatisfaction Following Total Knee Arthroplasty: A Systematic Review of the Literature","volume":"32","author":"Gunaratne","year":"2017","journal-title":"J. Arthroplast."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1007\/s11999-012-2533-y","article-title":"Postoperative alignment and ROM affect patient satisfaction after TKA","volume":"471","author":"Matsuda","year":"2013","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1253","DOI":"10.1302\/0301-620X.92B9.24394","article-title":"Predicting dissatisfaction following total knee replacement: A prospective study of 1217 patients","volume":"92","author":"Scott","year":"2010","journal-title":"J. Bone Jt. Surg. Br."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1186\/s43019-021-00106-2","article-title":"Comparison of post-operative three-dimensional and two-dimensional evaluation of component position for total knee arthroplasty","volume":"33","author":"Tanifuji","year":"2021","journal-title":"Knee Surg. Relat. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"S249","DOI":"10.1016\/j.arth.2018.02.046","article-title":"Periarticular Soft Tissue Envelope Size and Postoperative Wound Complications Following Total Knee Arthroplasty","volume":"33","author":"Yu","year":"2018","journal-title":"J. Arthroplast."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1302\/2058-5241.4.190022","article-title":"Robotic technology in total knee arthroplasty: A systematic review","volume":"4","author":"Kayani","year":"2019","journal-title":"EFORT Open Rev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2049","DOI":"10.1007\/s00402-021-04048-y","article-title":"Concepts and techniques of a new robotically assisted technique for total knee arthroplasty: The ROSA knee system","volume":"141","author":"Batailler","year":"2021","journal-title":"Arch. Orthop. Trauma Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1302\/0301-620X.100B7.BJJ-2017-1449.R1","article-title":"Robotic-arm assisted total knee arthroplasty is associated with improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based total knee arthroplasty: A prospective cohort study","volume":"100","author":"Kayani","year":"2018","journal-title":"Bone Jt. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1080\/24699322.2018.1519038","article-title":"Accuracy assessment of a novel image-free handheld robot for Total Knee Arthroplasty in a cadaveric study","volume":"23","author":"Casper","year":"2018","journal-title":"Comput. Assist. Surg."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1055\/s-0038-1641729","article-title":"Robotic-Arm Assisted Total Knee Arthroplasty Demonstrated Greater Accuracy and Precision to Plan Compared with Manual Techniques","volume":"32","author":"Hampp","year":"2019","journal-title":"J. Knee Surg."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3585","DOI":"10.1007\/s00167-020-06283-z","article-title":"MAKO CT-based robotic arm-assisted system is a reliable procedure for total knee arthroplasty: A systematic review","volume":"29","author":"Batailler","year":"2021","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1007\/s00264-022-05630-8","article-title":"The learning curve of imageless robot-assisted total knee arthroplasty with standardised laxity testing requires the completion of nine cases, but does not reach time neutrality compared to conventional surgery","volume":"47","author":"Vermue","year":"2023","journal-title":"Int. Orthop."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1007\/s00264-022-05618-4","article-title":"How long does image based robotic total knee arthroplasty take during the learning phase? Analysis of the key steps from the first fifty cases","volume":"47","author":"Shatrov","year":"2023","journal-title":"Int. Orthop."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2974","DOI":"10.1111\/ans.17975","article-title":"Robotic-arm assisted total knee arthroplasty has a learning curve of 16 cases and increased operative time of 12\u2009min","volume":"92","author":"Tay","year":"2022","journal-title":"ANZ J. Surg."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1186\/s40634-022-00524-5","article-title":"Introduction of ROSA robotic-arm system for total knee arthroplasty is associated with a minimal learning curve for operative time","volume":"9","author":"Bolam","year":"2022","journal-title":"J. Exp. Orthop."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1007\/s11701-021-01254-z","article-title":"The successful implementation of the Navio robotic technology required 29 cases","volume":"16","author":"Bell","year":"2022","journal-title":"J. Robot. Surg."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1007\/s11999-012-2407-3","article-title":"Robotic-assisted TKA reduces postoperative alignment outliers and improves gap balance compared to conventional TKA","volume":"471","author":"Song","year":"2013","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.1007\/s00167-011-1400-9","article-title":"Simultaneous bilateral total knee arthroplasty with robotic and conventional techniques: A prospective, randomized study","volume":"19","author":"Song","year":"2011","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e1334","DOI":"10.3928\/01477447-20120822-18","article-title":"Robot-assisted implantation improves the precision of component position in minimally invasive TKA","volume":"35","author":"Kim","year":"2012","journal-title":"Orthopedics"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2666","DOI":"10.1007\/s00167-021-06452-8","article-title":"Learning curve for active robotic total knee arthroplasty","volume":"30","author":"Mahure","year":"2022","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_25","first-page":"135","article-title":"Accuracy of Advanced Active Robot for Total Knee Arthroplasty: A Cadaveric Study","volume":"37","author":"Lee","year":"2023","journal-title":"J. Knee Surg."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1483","DOI":"10.1007\/s00402-013-1841-3","article-title":"The impact of resident involvement on post-operative morbidity and mortality following orthopaedic procedures: A study of 43,343 cases","volume":"133","author":"Schoenfeld","year":"2013","journal-title":"Arch. Orthop. Trauma Surg."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1375","DOI":"10.1007\/s11999.0000000000000002","article-title":"Resident Participation is Not Associated with Worse Outcomes After TKA","volume":"476","author":"Bao","year":"2018","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.artd.2022.02.029","article-title":"Does Resident Participation Influence Surgical Time and Clinical Outcomes? An Analysis on Primary Bilateral Single-Staged Sequential Total Knee Arthroplasty","volume":"15","author":"Maheshwari","year":"2022","journal-title":"Arthroplast. Today"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"236","DOI":"10.4055\/cios20308","article-title":"Clinical Results after Design Modification of Lospa Total Knee Arthroplasty System: Comparison between Posterior-Stabilized (PS) and PS Plus Types","volume":"14","author":"Lee","year":"2022","journal-title":"Clin. Orthop. Surg."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"326","DOI":"10.5792\/ksrr.18.028","article-title":"Reliability and Validity of the Femorotibial Mechanical Axis Angle in Primary Total Knee Arthroplasty: Navigation versus Weight Bearing or Supine Whole Leg Radiographs","volume":"30","author":"Kim","year":"2018","journal-title":"Knee Surg. Relat. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1007\/s11999-016-5097-4","article-title":"What Differences in Morphologic Features of the Knee Exist Among Patients of Various Races? A Systematic Review","volume":"475","author":"Kim","year":"2017","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1097\/00003086-198911000-00003","article-title":"The Knee Society total knee arthroplasty roentgenographic evaluation and scoring system","volume":"248","author":"Ewald","year":"1989","journal-title":"Clin. Orthop. Relat. Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1033","DOI":"10.1302\/0301-620X.100B8.BJJ-2018-0040.R1","article-title":"The learning curve associated with robotic-arm assisted unicompartmental knee arthroplasty: A prospective cohort study","volume":"100","author":"Kayani","year":"2018","journal-title":"Bone Jt. J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1007\/s00167-021-06814-2","article-title":"Robotic-arm assisted unicompartmental knee arthroplasty system has a learning curve of 11 cases and increased operating time","volume":"31","author":"Tay","year":"2023","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2851","DOI":"10.1007\/s00264-021-05179-y","article-title":"Imageless robotic-assisted total knee arthroplasty accurately restores the radiological alignment with a short learning curve: A randomized controlled trial","volume":"45","author":"Thiengwittayaporn","year":"2021","journal-title":"Int. Orthop."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2119","DOI":"10.1007\/s00402-021-04036-2","article-title":"Imageless robotic handpiece-assisted total knee arthroplasty: A learning curve analysis of surgical time and alignment accuracy","volume":"141","author":"Savov","year":"2021","journal-title":"Arch. Orthop. Trauma Surg."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1186\/s40634-021-00438-8","article-title":"The initial learning curve for the ROSA\u00ae Knee System can be achieved in 6-11 cases for operative time and has similar 90-day complication rates with improved implant alignment compared to manual instrumentation in total knee arthroplasty","volume":"8","author":"Vanlommel","year":"2021","journal-title":"J. Exp. Orthop."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2799","DOI":"10.1016\/j.arth.2019.06.040","article-title":"Accuracy of a New Robotically Assisted Technique for Total Knee Arthroplasty: A Cadaveric Study","volume":"34","author":"Parratte","year":"2019","journal-title":"J. Arthroplast."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1055\/s-0039-1700570","article-title":"Accuracy of Bone Resection in MAKO Total Knee Robotic-Assisted Surgery","volume":"34","author":"Sires","year":"2021","journal-title":"J. Knee Surg."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1007\/s00167-020-06341-6","article-title":"Robot-assisted total knee arthroplasty is associated with a learning curve for surgical time but not for component alignment, limb alignment and gap balancing","volume":"30","author":"Vermue","year":"2022","journal-title":"Knee Surg. Sports Traumatol. Arthrosc."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/3\/533\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T11:41:06Z","timestamp":1773402066000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/3\/533"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,13]]},"references-count":40,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["medicina62030533"],"URL":"https:\/\/doi.org\/10.3390\/medicina62030533","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,13]]}}}