Good clinical and radiological outcomes of anatomic total shoulder arthroplasty with a novel convertible all polyethylene glenoid with hybrid fixation: minimum 2-year follow-up

Abstract

BackgroundThe ideal glenoid implant for anatomic total shoulder arthroplasty (aTSA) is one that provides sound fixation and allows ease of conversion to a reverse shoulder arthroplasty should the clinical need arise. This study is the first to report a consecutive series of patients treated with a novel convertible all polyethylene glenoid with hybrid fixation. The aim of the study was to evaluate the clinical, functional, and radiological outcomes of aTSA, for treatment of primary glenohumeral joint osteoarthritis using the SMR TT Hybrid Glenoid. MethodsThis is a prospective study including consecutive patients from two centers in New Zealand and Sweden. Between August 29, 2017 and April 22, 2020, 103 patients received an aTSA for osteoarthritis with the SMR TT Hybrid Glenoid implant (LimaCorporate, San Daniele del Friuli, Italy). Ninety-seven patients had a minimum follow-up of 24 months and were therefore included in this study. There were 45 female and 52 male patients. The average age at the time of surgery was 68.2 years (range 49-81 years). Preoperative and postoperative clinical evaluations were performed using the American Shoulder and Elbow Surgeons score and the Oxford Shoulder Score. Preoperative and postoperative range of motion measures were conducted using a goniometer. Standardized Grashey and axillary lateral radiographs were utilized to assess for evidence of glenoid and humeral component failure and loosening. ResultsThe mean follow-up duration was 2.3 years (range 2.0-4.6 years). The mean preoperative and postoperative American Shoulder and Elbow Surgeons scores were 29.0 ± 12.4 and 90.3 ± 14.5, respectively (P < .001). The mean preoperative and postoperative Oxford Shoulder Scores were 21.0 ± 6.7 and 45.3 ± 4.4, respectively (P < .001). We found significant improvements in the range of motion, with mean forward flexion increasing from 87° to 155° and abduction 73° to 149°, respectively. Radiologically, there was no evidence of glenoid or humeral component failure or loosening. Six patients had evidence of reduced bone density around the humeral component. Two patients had repair of traumatic rupture of subscapularis tendon in the early postoperative period. None of the patients had revision of the glenoid or humeral components. ConclusionsPatients treated with an aTSA with the SMR TT Hybrid Glenoid, a novel glenoid implant that has the potential to simplify the process of revision, achieved promising clinical and radiologic results at a minimum of two years.