Patellar height after unicompartmental knee arthroplasty: comparison between fixed and mobile bearing

• Published in: Archives of orthopaedic and trauma surgery 2022-11, Vol.142 (11), p.3449-3460
• Main Authors: D’Ambrosi, Riccardo, Buda, Matteo, Nuara, Alessandro, Mariani, Ilaria, Scelsi, Michele, Valli, Federico, Ursino, Nicola, Hirschmann, Michael Tobias
• Format: Article
• Language: English
• Subjects: Clinical outcomes; Joint replacement surgery; Knee; Knee Arthroplasty; Medicine; Medicine & Public Health; Orthopedics
• ISSN: 1434-3916; 0936-8051; 1434-3916
• DOI: 10.1007/s00402-021-04183-6

Purpose The purpose of this study was to determine the changes in patellar heights by comparing standardised pre- and post-operative radiographs in a consecutive series of patients undergoing unicompartmental knee arthroplasty (UKA) with two different approaches and implant designs [fixed bearing (FB) vs mobile bearing (MB)] and to correlate the patellar heights with clinical outcomes. Methods One hundred and seventy-two UKA patients were prospectively enrolled in the study. 75 patients underwent a minimally invasive FB medial UKA (referred to hereinafter as the ‘FB group’); 97 patients were treated with a minimally invasive MB medial UKA. The pre-operative and mid-term (1-year) post-operative patellar heights and clinical scores of these groups of patients were compared using the Insall–Salvati (IS) and Caton–Deschamps (CD) indices and the Oxford Knee Score (OKS). Results No differences were found between the two groups either with regard to the pre-operative data ( p > 0.05) or between pre- and post-operative radiographic scores at the time of each follow-up ( p > 0.05). Both the groups reported a significant clinical improvement ( p