Clinical outcomes of a canal-sparing shoulder arthroplasty system at a minimum of 2-year follow-up

Abstract

BackgroundStemless implants in anatomic total shoulder arthroplasty (TSA) have demonstrated comparable results to stemmed implants with both spherical and elliptical humeral heads. The primary purpose of this study is to report the 2-year clinical outcomes of a new cohort of patients that underwent anatomic TSA using an elliptical humeral head and multiplanar osteotomy system. MethodsPatients who underwent anatomic TSA with the Catalyst total shoulder system (OrthoScience) from 2017 to 2019 by a single surgeon were included in this study. Preoperative shoulder radiographs, computer tomography scans, and/or magnetic resonance imagings were reviewed and classified according to the Walch Classification. At a minimum of 2-year follow-up, patient-reported outcome measurements (PROMs) were obtained, including the Western Ontario Osteoarthritis Shoulder index, American Shoulder and Elbow Surgeons score, Patient-Reported Outcomes Measurement Information System upper extremity, and the Single Assessment Numerical Evaluation (SANE) score. PROMs were stratified by age, body mass index, and medical comorbidities. Revisions, secondary surgeries, and any radiographic notes of hardware loosening were also recorded. ResultsForty anatomic TSAs in 38 patients met inclusion criteria for the study. The average age of the cohort was 66.1 year old, 45% male, and with a mean body mass index of 31.5. PROMs were available for 27 out of 40 patients (70%) with a mean follow-up time of 33.9 ± 5.2 months. Radiographic analysis demonstrated that 6/27 (22%) were Walch A2 type glenoids while 21/27 (78%) were Walch B2 type glenoids. The mean PROMs for the cohort were as follows: Western Ontario Osteoarthritis Shoulder index (91.2 ± 8.8), American Shoulder and Elbow Surgeons score (85.4 ± 14.7), Patient-Reported Outcomes Measurement Information System upper extremity (31.5 ± 3.6), SANE ipsilateral (83.8 ± 15.9), and SANE contralateral (85.7 ± 10.3). Three patients (11%) required revision surgery, including 2 subscapularis repairs, and 1 revision to a reverse TSA. ConclusionThe present study demonstrated clinical outcomes using an ellipsoid anatomic TSA system on a high percentage of patients with B2 type glenoids at a minimum of 2-year follow-up. Further study is warranted to evaluate long-term outcomes of this new stemless ellipsoid anatomic TSA system.