2019 ISAKOS Biennial Congress ePoster #929
The Learning Curve Associated with Robotic-Arm Assisted Unicompartmental Knee Arthroplasty: A Prospective Cohort Study
Babar Kayani, BSc (HONS), MBBS, MRCS (Eng), London UNITED KINGDOM
Sujith Konan, MD(Res), MBBS, MRCS, FRCS(Tr&Orth), London UNITED KINGDOM
Jurek R. T. Pietrzak, MBBCh, FCS(SA)Orth, London UNITED KINGDOM
Sumon S. Huq, MBBS, MRCS, London UNITED KINGDOM
Jenni Tahmassebi, BSc, London UNITED KINGDOM
Fares S. Haddad, MCh(Orth), BSc, FRCS(Orth), London UNITED KINGDOM
University College London Hospital, London, UNITED KINGDOM
FDA Status Cleared
Summary
Robotic-arm assisted UKA was associated with a learning curve of six cases for operating time and surgical team confidence levels but no learning curve for accuracy of implant positioning.
Abstract
Aims:
The primary aim of this study was to determine the surgical team’s learning curve for introducing robotic-arm assisted unicompartmental knee arthroplasty (UKA) into routine surgical practice. The secondary objective was to compare accuracy of implant positioning in conventional jig-based UKA versus robotic-arm assisted UKA.
Patients and Methods:
This prospective single-surgeon cohort study included 60 consecutive conventional jig-based UKAs compared with 60 consecutive robotic-arm assisted UKAs for medial compartment knee osteoarthritis. Patients undergoing conventional UKA and robotic-arm assisted UKA were well-matched for baseline characteristics including a mean age of 65.5 years (SD 6.8) vs 64.1 years (SD 8.7), (p = 0.31); a mean body mass index of 27.2 kg.m2 (SD 2.7) vs 28.1 kg.m2 (SD 4.5), (p = 0.25); and gender (27 males: 33 females vs 26 males: 34 females, p = 0.85). Surrogate measures of the learning curve were prospectively collected. These included operative times, the Spielberger State-Trait Anxiety Inventory (STAI) questionnaire to assess preoperative stress levels amongst the surgical team, accuracy of implant positioning, limb alignment, and postoperative complications.
Results
Robotic-arm assisted UKA was associated with a learning curve of six cases for operating time (p < 0.001) and surgical team confidence levels (p < 0.001). Cumulative robotic experience did not affect accuracy of implant positioning (p = 0.52), posterior condylar offset ratio (p = 0.71), posterior tibial slope (p = 0.68), native joint line preservation (p = 0.55), and postoperative limb alignment (p = 0.65). Robotic-arm assisted UKA improved accuracy of femoral (p < 0.001) and tibial (p < 0.001) implant positioning with no additional risk of postoperative complications compared to conventional jig-based UKA.
Conclusion
Robotic-arm assisted UKA was associated with a learning curve of six cases for operating time and surgical team confidence levels but no learning curve for accuracy of implant positioning.