Early clinical and radiographic outcomes of anatomic total shoulder arthroplasty with a biconvex posterior augmented glenoid for patients with posterior glenoid erosion: minimum 2-year follow-up

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

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.

Tornier Perform Anatomic Augmented Glenoid Implants correct posterior subluxation and maintain active joint reduction in Walch B2 glenoids

BACKGROUND

The Walch type B2 glenoid is characterized by retroversion, posteroinferior erosion and posterior humeral head subluxation. A surgical management option for a B2 glenoid is an anatomic total shoulder arthroplasty (aTSA) with a posteriorly augmented all-posterior augmented glenoid (PAG) implant. However, little is known about what occurs actively at the glenohumeral articulation after aTSA with a PAG. Additionally, most studies on B2 glenoids, whether pre-aTSA or post-aTSA, assess subluxation statically. Presently, it is unknown if subluxation recurs after aTSA with a PAG or if it varies dynamically throughout active motion. Therefore, the primary objective of this study was to determine if Walch type B2 patients managed with an aTSA and a PAG (Tornier Perform Anatomic Augmented Glenoid Implant) would maintain correction of subluxation when examined statically and when stressed with active motion. The secondary objective was to analyze if a patient's range of motion (good or limited), magnitude of B2, or PAG implant size (15° or 25°) affect postoperative correction of subluxation.

METHODS

Twenty Walch type B2 patients (mean age 68 years, range 54-83) underwent stemless aTSA with a 15° or 25° PAG implant and were assessed at a minimum 2-year follow-up. All patients underwent dynamic four-dimensional computed tomography scanning to actively track glenohumeral implant alignment and subluxation during a provocative active internal rotation (IR) motion protocol. Bone and implant 3D models of the humerus and scapula for each four-dimensional computed tomography scan were created using 3D Slicer. Landmarks were selected on the models to create coordinate systems that were then used in conjunction with a custom program (MATLAB) to determine subluxation preoperatively (statically), and postoperatively (dynamically).

RESULTS

Posterior humeral head subluxation was significantly corrected (P < .001) from an average of 66% (range 51%-98%) preoperatively to 54% (range 41%-77%) postoperatively. Concentric aTSA joint alignment was maintained throughout an active IR motion protocol, as subluxation percentage only varied by 1% throughout IR movement (range 54%-55%). Neither patient IR range of motion (good or limited) nor size of PAG (15° or 25°) had a significant effect (P > .05) on subluxation postoperatively.

CONCLUSION

At short-term follow-up, aTSA with an all-polyethylene PAG (Tornier Perform Anatomic Augmented Glenoid Implant) was successful at restoring and maintaining glenohumeral alignment with correction of subluxation throughout a provocative active IR motion protocol. As such, recurrence of subluxation does not occur statically or actively in patients who have undergone glenoid reconstruction with correction of posteroinferior erosion with a half-wedge PAG implant. Thus, aTSA with a PAG implant is an acceptable option for patients with mild or moderate B2 glenoids.

Inconsistencies in measuring glenoid version in shoulder arthroplasty: a systematic review

BACKGROUND

Glenoid version is a critical anatomic parameter relied upon by many surgeons to inform preoperative planning for shoulder arthroplasty. Advancements in imaging technology have prompted measurements of glenoid version on various imaging modalities with different techniques. However, discrepancies in how glenoid version is measured within the literature have not been well characterized.

METHODS

A literature search was performed by querying PubMed, EMBASE, CINAHL, and Cochrane computerized databases from their inception through December 2023 to identify studies that assessed the relationship between preoperative glenoid version and at least one clinical or radiologic outcome following shoulder arthroplasty. Study quality was assessed via the Methodologic Index for Nonrandomized Studies criteria. Imaging modalities and techniques for measuring glenoid version, along with their association with clinical outcomes, were aggregated.

RESULTS

Among 61 studies encompassing 17,070 shoulder arthroplasties, 27 studies (44.3%) described explicitly how glenoid version was measured. The most common imaging modality to assess preoperative glenoid version was computed tomography (CT) (63.9%), followed by radiography (23%); 11.5% of studies used a combination of imaging modalities within their study cohort. Among the studies using CT, 56.5% utilized two-dimensional (2D) CT, 41.3% utilized three-dimensional (3D) CT, and 2.2% used a combination of 2D and 3D CT. The use of 3D CT increased from 12.5% of studies in 2012-2014 to 25% of studies in 2018-2020 to 52% of studies in 2021-2023 (ptrend = 0.02). Forty-three (70.5%) studies measured postoperative version, most commonly on axillary radiograph (22 [51.2%]); 34.9% of these studies used different imaging modalities to assess pre- and postoperative version.

CONCLUSIONS

This systematic review revealed marked discrepancies in how glenoid version was measured and reported in studies pertaining to shoulder arthroplasty. A temporal trend of increased utilization of 3D CT scans and commercial preoperative planning software was identified. Improved standardization of the imaging modality and technique for measuring glenoid version will enable more rigorous evaluation of its impact on clinical outcomes.

Advances in Anatomic Total Shoulder Arthroplasty Glenoid Implant Design

Since the advent of Neer's total shoulder arthroplasty in 1974, glenoid implant design has evolved to optimize patient function and increase implant longevity. Glenoid loosening continues to be a major cause of total shoulder arthroplasty failure due to both patient and implant factors. The more recent development of posterior augmented glenoids, peg fixation with ingrowth potential, inlay implants, zoned conformity implants, and convertible glenoids have all shown promising results in improving glenoid fixation and survival in different clinical circumstances. The increased utilization of 3D CT scans, preoperative planning, and patient-specific instrumentation has paralleled innovation in glenoid implants with the aim of improving the accuracy of glenoid implant placement to further optimize patient function and implant longevity. Specific indications for the variety of glenoid implants available today are still being studied. The shoulder arthroplasty surgeon should consider patient and implant factors and patient goals when determining the appropriate implant for each individual.

Surgical management of biconcave glenoids: a scoping review

Biconcave (B2) glenoids, characterized by significant posterior glenoid bone loss and a biconcave wear pattern, are a challenging pathology in shoulder surgery. Significant bone defects present in B2 glenoids increases the risk of complications and rates of failure for operative patients with glenohumeral osteoarthritis. Diagnosing this entity is of pivotal importance, and can be accomplished with imaging and a comprehensive clinical investigation. There are no clear-cut guidelines for management, but options include hemiarthroplasty, anatomic total shoulder arthroplasty, and reverse shoulder arthroplasty. In recent years, modern techniques such as corrective reaming, bone grafts, and the use of augmented components have improved patient outcomes. Educating prospective patients is essential for reaching a shared management decision, setting appropriate expectations, and optimizing prognostic outcomes.

The role of the anterior shoulder joint capsule in primary glenohumeral osteoarthritis

The pathogenesis of primary glenohumeral arthritis (GHOA) is mediated by a complex interaction between osseous anatomy and the surrounding soft tissues. Recently, there has been growing interest in characterizing the association between the anterior shoulder joint capsule and primary GHOA because of the potential for targeted treatment interventions. Emerging evidence has shown substantial synovitis, fibrosis, and mixed inflammatory cell infiltrate in the anterior capsule of osteoarthritic shoulders. In addition, increased thickening of the anterior shoulder joint capsule has been associated with greater posterior glenoid wear and humeral head subluxation. While these findings suggest that anterior capsular disease may play a causative role in the etiology and progression of eccentric GHOA, further studies are needed to support this association. The purpose of this article is to review the pathogenesis of primary GHOA, contextualize current hypotheses regarding the role of the anterior capsule in the disease process, and provide directions for future research.

Anatomic shoulder arthroplasty with high side reaming versus reverse shoulder arthroplasty for eccentric glenoid wear patterns with an intact rotator cuff: comparing early versus midterm outcomes with minimum 7 years of follow-up

BACKGROUND

Eccentric glenoid bone loss patterns (B- and C-type glenoid) pose a difficult challenge when performing shoulder arthroplasty. Anatomic total shoulder arthroplasty with preferential high-side reaming (ATSA + HSR) has been an accepted method to treat this problem. Reverse shoulder arthroplasty (RSA) has become an alternative method to manage these cases with eccentric glenoid wear. The purpose of this study was to compare the early 2-year outcomes with the midterm outcomes for patients who underwent ATSA + HSR vs. RSA for eccentric glenoid wear patterns with an intact rotator cuff.

MATERIALS AND METHODS

From 2008 to 2014 there were 242 shoulder arthroplasties performed in the setting of eccentric glenoid wear patterns. Of that initial cohort 101 ATSA + HSR and 93 RSA had both 2-year and final follow-up with a minimum of 7 years from surgery. American Shoulder and Elbow Surgeons (ASES) scores, Simple Shoulder Test (SST), range of motion, patient satisfaction, and radiographs were evaluated for each cohort and contrasted at the 2-year follow-up point and last follow-up time point.

RESULTS

The average follow-up in the ATSA + HSR cohort was 8.3 years compared with 7.8 years in the RSA cohort. At the 2-year follow-up point, the ATSA + HSR group had better average ASES scores (85 vs. 80 [P < .001]), SST scores (10 vs. 9.6 [P < .001]), forward elevation (162° vs. 151° [P < .001]), external rotation (47° vs. 42° [P < .001]), and internal rotation (IR) (80% full IR vs. 55% full IR [P < .001]). At the 2-year follow-up, 95% of the ATSA + HSR cohort were satisfied compared with 93% in the RSA cohort. At the final follow-up, the RSA group had better average ASES scores (80 vs. 77 [P < .001]) and SST scores (9.4 vs. 8 [P < .001]) and a similar forward elevation (152° vs. 149° [P = .025]). The ATSA + HSR had better external rotation (45° vs. 41° [P < .001]) and IR (74% full IR vs. 54% full IR [P = .005]). Patient satisfaction at the final follow-up had decreased to 82% in the ATSA + HSR group, compared with 95% satisfied in the RSA group. Of the initial ATSA + HSR cohort, 8% of patients had undergone revision compared with 2% in the RSA cohort.

CONCLUSION

ATSA with HSR had better outcome scores and range of motion with a similar patient satisfaction rating to RSA at the 2-year point. Over time, the ATSA + HSR results deteriorated, and at the final midterm follow-up, the RSA group had more durable results with better outcome scores, a higher patient satisfaction rating, and a lower revision rate.