Outcomes of Corrective, Concentric (C2) Glenoid Reaming combined with Pyrocarbon Hemiarthroplasty for B2, B3 Glenoid Arthritis.

BACKGROUND: Posterior humeral subluxation (PHS) in B2/B3 glenoid is a cause of asymmetric long-term stress on the glenoid and the potential reason for glenoid loosening in anatomic total shoulder arthroplasty (ATSA) and painful glenoid erosion in hemiarthroplasty with metallic heads (HA-Metal). We hypothesized that corrective and concentric reaming (CCR) of the glenoid associated with pyrocarbon hemiarthroplasty (HA-PYC) could improve the centering of the humeral head and decrease the risk of persistent painful glenoid erosion in young/active patients with B2/B3 glenoid. METHODS: Between 2014 and 2020, 41shoulders (in 35 patients, mean age of 57.9 years) underwent HA-PYC combined with CCR reaming for B2 (n=30) or B3 (n=11) osteoarthritis. Patients were prospectively followed with computed tomography (CT) scans performed preoperatively, immediate postoperatively and at last follow-up (> 2 years). The primary outcomes were 3D-corrected CT-scan measurements of glenoid version, PHS, progression of glenoid erosion. Secondary outcomes included functional outcome scores, return to activities, and revision rate and complications. RESULTS: At a mean follow-up of 4.5 years (2 to 9.5 years), the prosthesis survival was 95% (39/41). No patient has been reoperated for painful glenoid erosion. The mean glenoid retroversion decreased from 17.1° ± 7.5 preoperatively to 8.3° ± 8.2 at last follow-up (p=0.001), and the mean PHS from 74% to 56.5% (p=0.001) based on the scapular plane and from 59.9% to 50.3% based on the glenoid plane. The humeral head was recentered in 97% according to the glenoid surface and 71% according to the scapular plane. Correction of PHS in the scapular plane was highly correlated to correction of glenoid retroversion (p<0.001). CT-scan measurements showed that the average total medialization was 3.7 ± 3.2 mm (2.0 ± 1.8 mm due to reaming and only 1.7 ± 2.4 mm due to erosion). The Adjusted Constant score increased from 43% ± 13 to 97% ± 16 and the Subjective Shoulder Value from 38% ± 14 to 84 % ± 12 (p<0.001). Overall, 84% of active patients returned to work and all patients returned to sports. CONCLUSION: In B2/B3 glenoid arthritis, corrective, concentric glenoid reaming combined with HA-PYC improves centering of the humeral head and shows a low risk of painful glenoid erosion at mid-term follow-up. The combined procedure results in excellent functional outcomes and high prosthesis survivorship at mid-term follow-up. HA-PYC and CCR is offering an alternative shoulder arthroplasty for young/active patients with B2/B3 glenoid osteoarthritis who want to return to work or sports practice.

Total shoulder arthroplasty for primary glenohumeral osteoarthritis: does posterior humeral subluxation persist after correction of the glenoid version at 5 years minimum?

BACKGROUND: Primary glenohumeral osteoarthritis is associated with both excessive posterior humeral subluxation (PHS) and excessive glenoid retroversion in 40% of cases. These morphometric abnormalities are a particular issue because they may be responsible for a deterioration in long-term clinical and radiologic outcomes. The aim of this study was to perform a computed tomographic (CT) analysis of patients who underwent total shoulder arthroplasty (TSA) for primary osteoarthritis (OA) with B2-, B3-, or C-type glenoids in whom an attempt was made to correct for excessive glenoid retroversion and excessive posterior humeral subluxation intraoperatively. MATERIAL: We performed a retrospective, single-center study including 62 TSA patients with a preoperative PHS of the glenohumeral joint (31 men, 31 women, 70 ± 9 years) between January 2000 and January 2014. Glenoids were classified as B2 (32 cases), B3 (13 cases), or C (17 cases). Glenoid retroversion was corrected by anterior asymmetric reaming. Patients were reviewed for clinical and CT scan assessment with a mean follow-up of 8.3 years (minimum 5 years). At final follow-up, the CT images were reconstructed in the scapular plane. A PHS index >65% defined persistence. RESULTS: The revision-free rate was estimated at 93%. Correlation between PHS and retroversion was moderate preoperatively (ρ = 0.58) and strong at final follow-up (ρ = 0.73). Postoperative CT scans on average showed a surgical correction of PHS compared to preoperatively (79% vs. 65% respectively, P < .05) and retroversion (20° vs. 10° respectively, P < .05). At final follow-up, 25 of 62 patients had a persistence in the 2-dimensional (2D) model and 41 of 62 in the corrected 2D model. Persistence of PHS had no influence on clinical outcomes but did demonstrate a significantly higher glenoid loosening rate (20% vs. 59%, P < .05). CONCLUSION: Correlation between PHS and retroversion was moderate preoperatively and strengthened at long-term follow-up. Anterior asymmetric reaming allowed for a surgical improvement of both PHS and retroversion, but it was not sufficient to maintain a correction over time. Glenoid loosening was more frequent in case of PHS persistence but seemingly without clinical relevance.

Total shoulder arthroplasty using trabecular metal augments to address glenoid retroversion: the preliminary result of 10 patients with minimum 2-year follow-up.

BACKGROUND: Options to address glenoid retroversion include eccentric reaming, bone grafting, modifications to component shape, and reverse shoulder arthroplasty. Trabecular metal (TM) augments have been used extensively in the hip and knee to address bone deficiency in arthroplasty as part of a hybrid combination of high-density polyethylene, polymethyl methacrylate, and TM. This study presents the initial results of the use of specifically designed augments in the shoulder to address glenoid retroversion as part of total shoulder arthroplasty (TSA). MATERIALS: Ten patients (4 women and 6 men; aged 60 to 79 years) with Walch grade B2 or C glenoids have undergone TM glenoid augment insertion as part of a TSA, with a longer than 24-month follow-up. Patients received a 15° or 30° TM wedge to correct excessive glenoid retroversion before the glenoid component was cemented. Outcome analysis was performed preoperatively, at 3, 6, and 12 months, and yearly thereafter. RESULTS: All patients have been satisfied, and all scores have improved. There have been no complications and no hardware failures or displacement. All glenoid components were implanted to within 10° of neutral glenoid version. Radiographs at 24 months show good incorporation of the TM augment and the glenoid component. CONCLUSIONS: The TM augments have the advantage of immediate secure fixation, no tendency to collapse, and the ability to correct retroversion of 25° or more. This study confirms the successful short-term outcome of wedge-shaped TM augments to correct glenoid retroversion as part of TSA.