Short-term outcomes of anatomic total shoulder arthroplasty with nonaugmented glenoid component for Walch B2 and B3 glenoid morphology.

Abstract

Background: The optimal management of posterior glenoid bone loss in glenohumeral osteoarthritis with anatomic total shoulder arthroplasty (aTSA) remains unknown, as the degree of bone loss and retroversion can vary across a wide spectrum in glenoids with Walch B2 and B3 morphology. The objectives of the current study were to evaluate the clinical and radiographic outcomes of utilizing standard, all-polyethylene, nonaugmented anchor-peg glenoid (APG) components in aTSA for patients with mild to moderate B2 or B3 morphology.

Methods: Between January 2010 and September 2019, we identified 79 shoulders with mild to moderate B2 or B3 glenoid morphology that underwent aTSA with use of a nonaugmented APG glenoid component and minimum 2 years clinical and radiographic follow-up. In each case, the surgeon had access to an augmented glenoid component but chose to use a standard component based upon the presence of mild to moderate deformity, defined as the ability to template components within 10° of premorbid glenoid vault retroversion and within 3 mm of premorbid glenoid vault joint line based on preoperative 3-dimensional computed tomography planning. The Penn Shoulder Score (PSS), glenoid anchor-peg osteolysis (APO) (grade 1 vs. 2 and 3), and humeral head subluxation (HHS) were the main outcomes of interest.

Results: The cohort included 63/79 (80%) B2 glenoids and 17/79 (21%) B3 glenoids. Median patient age at surgery was 64.2 years [interquartile range {IQR} 59.6; 68.5]; median preoperative retroversion was 13.0° [IQR 9.8; 15.4]; and median preoperative joint line medialization was 1.4 mm [IQR 0.4; 2.4]. Median follow-up duration was 4.3 years [IQR 2.5; 6.8]; The PSS and HHS were improved amongst all patients postoperatively (P < .0001), with a median PSS at latest follow-up of 96.0 [IQR 88.5; 99.0] and posterior HHS present in 11.8% at final follow-up. There were 4 complications in the cohort (5.0%), one of which required reoperation due to persistent posterior HHS. Postoperative grade 1 APO was present on latest radiographs in 8/79 (10.1%) cases. Walch classification, preoperative glenoid version, inclination, and joint line medialization as measured on 3-dimensional computed tomography were not significantly associated with PSS or APO at final follow-up. Higher PSS at final follow-up was associated with better shoulder range of motion. APO at final follow-up was not associated with lower PSS.

Discussion: The use of nonaugmented polyethylene APG components in patients undergoing aTSA with mild to moderate B2 and B3 glenoids results in significant improvements in clinical and radiographic outcomes with low complication and reoperation rates at short-term follow-up. Further follow-up of this cohort is needed to better understand the implications of glenoid component APO on loosening patterns and failure rates in the long-term.