title: Kinematic femoral alignment with gap balancing and patient-specific instrumentation in total knee arthroplasty: a randomized clinical trial.
abstract: While patient-specific instrumentation (PSI) in total knee arthroplasty (TKA) allows for transfer of the preoperative plan onto bony landmarks, the soft tissue balancing is not affected. The goals of this randomized clinical trial were to compare PSI and the measured resection technique (conventional) with PSI and the gap balancing technique. Fifty patients were randomized to TKA with conventional PSI (PSI-S) (n = 25) or to PSI with additional gap balancing (PSI-GB) (n = 25). All patients were clinically examined at 3 and 12 months postoperatively. Data on the range of motion, the Knee Society Score, the Western Ontario and McMasters Universities Osteoarthritis Index, the High-Flexion Knee Score (HFKS), and the Forgotten Joint Score (FJS) were compiled at follow-up. Statistically significant improvements were found for all clinical parameters in the PSI-GB group compared to the PSI-S group at 3 months postoperatively and for FS, FJS, and HFKS at 12 months. However, the relevance of these differences, as well as their effect on long-term outcomes, needs to be evaluated further. In conclusion, patient-specific instrumentation combined with gap balancing yielded good early clinical outcomes.
authors.affiliation: Clinic for Orthopedics, Sports Medicine and Rehabilitation, Krankenhaus Märkisch Oderland GmbH, Sonnenburger Weg 3, 16269, Wriezen, Germany. H.Hommel@khmol.de.
authors.forename: Hagen
authors.initials: H
authors.lastname: Hommel
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Abdel
authors.affiliation: Center for Musculoskeletal Surgery, Orthopedic Department, Charité University Hospital, Berlin, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Perka
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D013997:Time Factors
keywords: Extension-first technique; Gap balancing; Patient-specific instrumentation; Randomized clinical trial; Total knee arthroplasty