Posterior Humeral Head Subluxation Research Articles

Total Shoulder Arthroplasty Versus Reverse Shoulder Arthroplasty in Primary Glenohumeral Osteoarthritis With Intact Rotator Cuffs: A Meta-Analyses.

Traditional practice favors total shoulder arthroplasty (TSA) for the treatment of primary glenohumeral osteoarthritis (PGHO) with an intact rotator cuff; however, the indications for reverse shoulder arthroplasty (RSA) have expanded to include PGHO. The purpose of this systematic review is to compare the mean differences in the range of motion and patient-reported outcomes between the TSA and RSA with an intact rotator cuff and to analyze the subgroup of the Walch type B2 glenoid. This IRB-exempt, PROSPERO-registered systematic review strictly followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) guidelines. A literature search of five databases revealed 493 articles, of which 10 were included for quantitative synthesis. Level III evidence studies with the diagnosis of PGHO and ≥2 years of follow-up were included. Studies without preoperative and postoperative data were excluded. The Newcastle-Ottawa scale was used to evaluate the methodologic quality of the included studies. Preoperative and postoperative range of motion and patient-reported outcomes were collected. The random-effects model was employed, and p < 0.05 was considered statistically significant. There were a total of 544 and 329 studies in the TSA group and RSA group, respectively. The mean age in the TSA group and RSA groups were 65.36 ± 7.06 and 73.12 ± 2.40, respectively (p = 0.008). The percentages of males in the TSA and RSA groups were 73.2% and 51.1%, respectively (p = 0.02). The mean differences in forward elevation, external rotation in adduction, internal rotation scale, visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, and Single AssessmentNumericEvaluation (SANE) scores were improved for both groups with no significant differences between the two. There were 9.6 times the revisions in the TSA group (8.8% vs. 0.91%; p = 0.014) and 1.5 times the complications in the TSA group (3.68% vs. 2.4%; p = 0.0096). Two hundred and forty-two glenoids were identified as Walch type B2 (126 in the TSA groupand 116 in the RSA group). The mean ages in the B2 subgroup were 68.20 ± 3.25 and 73.03 ± 1.49 for the TSA and RSA, respectively (p = 0.25). The percentages of males in the B2 subgroup were 74.6% and 46.5% for the TSA and RSA groups, respectively (p = 0.0003). The ASES, SANE, forward elevation, and external rotation in the adduction results were descriptively summarized for this subgroup, with average mean differences of 49.0 and 51.2, 45.7 and 66.1, 77.6° and 58.6°, and 38.6° and 34.1° for the TSA and RSA groups, respectively. In the setting of primary glenohumeral osteoarthritis with an intact rotator cuff, the RSA has a similar range of motion and clinical outcomesbut lower complication and revision rates as compared to the TSA. This may hold true in the setting of the B2 glenoid, although a high-powered study on this subgroup is required. Anatomic shoulder arthroplasty maintains an important role in select patients. Further studies are required to better elucidate the role of glenoid bone loss and posterior humeral head subluxation with regard to implant choice.

Three-dimensional analysis of biplanar glenoid deformities: what are they and can they be virtually reconstructed with anatomic total shoulder arthroplasty implants?

Descriptions of glenoid deformities in glenohumeral osteoarthritis (GHOA) have focused on the axial plane. Less is known regarding arthritic glenoids with higher amounts of superior inclination and little evidence exists to guide management of inclination or combined version-inclination deformity when performing anatomic total shoulder arthroplasty (aTSA). We hypothesized that biplanar deformities (BD) would be present in a higher proportion of GHOA patients than previously appreciated, and these deformities would be difficult to adequately reconstruct with contemporary aTSA implants. A retrospective query was performed of GHOA patients indicated for TSA 2012-2017 with a computed tomography (CT) scan within three months of surgery. Images were uploaded to three-dimensional (3D) software for automated measurements. Glenoids with superior inclination ≥10°, and retroversion ≥20° were considered to have BD. Walch classification was determined, and C-type glenoids were excluded. Rotator-cuff muscle cross-sectional area (CSA) was measured and fatty infiltration was graded. Glenoids withBD were virtually planned for aTSA with correction to neutral inclination and version, then with 5° superior inclination and 10° retroversion. Two-hundred and sixty-eight shoulders in 250 patients were included; average age was 65years, 67% male. There were no differences in inclination between Walch types (P=.25). Twenty-nine shoulders with BD were identified (11%). These deformities were not associated with age (P=.47) or gender (P=.50) but were skewed towards Walch B-type, specifically B2 (P=.03). Acromial index and posterior humeral head subluxation were higher in BD patients (P=.04, P<.001, respectively). Biplanar deformities had similar cuff CSA compared to those without but were less frequently associated with fatty infiltration of the subscapularis (P=.05). When correcting to neutral version and inclination, 41% BD could not be reconstructed. Of those that could, 94% required augmented implants. When correcting to 5° superior inclination and 10° retroversion, 10% could not be reconstructed. Of those that could, 58% required augmented implants. With partial correction, augment use was predicted by retroversion >26° (P=.009). Inclination did not predict augment use (P=.90). Final implant position commonly involved unseating in the posterosuperior quadrant and cancellous exposure in the anteroinferior quadrant. This retrospective computed tomography (CT)-based study of 268 shoulders with GHOA found an 11% prevalence of BD. These deformities were commonly associated with Walch B2 wear patterns. Virtual aTSA planning showed a high failure rate (41%) when correcting to neutral version and inclination. Posteriorly augmented implants were frequently required, and often still involved unseating in the posterosuperior quadrant, increased cancellous exposure in the anteroinferior quadrant, and vault perforation.

BIO-RSA vs metal augmented baseplate in shoulder osteoarthritis with multiplanar glenoid deformity: a comparative study of radiographic findings and patient outcomes.

Reverse shoulder arthroplasty (RSA) requiring extensive reaming to address severe glenoid bone loss increases the risk of glenoid medialization and baseplate failure. We hypothesized that i) metal augmented baseplate prevents the medialization of the joint line and preserves glenoid bone stock similarly to BIO-RSA; ii) bone graft viability and healing in BIO-RSA patients become compromised over time. Eighty-one patients (83 shoulders) underwent glenoid lateralization with bone (BIO-RSA group, 44) or metal augmented baseplate (MIO-RSA group, 39) and a minimum follow-up of 24 months were included. The orientation and direction of glenoid erosion was identified and recorded using computerized 3D planning. Active range of motion, and the Western Ontario Osteoarthritis of the Shoulder (WOOS) index were assessed before arthroplasty and at the last follow-up visits. Radiographic changes around the glenoid and humeral components were assessed. Healing and thickness of bone graft were evaluated by predefined criteria. Postoperative global glenoid inclination (β angle) and retroversion were also measured. Delta scores of active anterior elevation were higher in the MIO-RSA group (p= 0.027). The differences in the other planes of shoulder motion and in WOOS index scores between the groups were not significant. Preoperative glenoid retroversion was higher in BIO-RSA patients, glenoid inclination was similar in both groups. Type B2 and B3 glenoids had a posterior-central (91%) and posterior-superior (90%) erosion with a mean posterior humeral head subluxation of 76% and 78%, respectively. The direction of erosion in Type E2 and E3 glenoids was posterior-superior, with a mean posterior humeral head subluxation of 74%. The rate of high position of the glenosphere was higher in the BIO-RSA group (p = 0.022), while the values of β angle and postoperative retroversion were similar in the two groups. BIO-RSA group showed radiolucent lines < 2mm around the bone graft in 16 patients (36.4%) and decreased thickness in 15 (34.1%). Incomplete baseplate seating was found in 4 MIO-RSA patients (10%). We found higher rate of humerus condensation lines in MIO-RSA patients (p= 0.01) and higher rate of cortical thinning and tuberosity resorption in the BIO-RSA group (p= 0.027 and p = 0.004, respectively). Metal augmented glenoid is a suitable alternative to BIO-RSA to preserve bone and prevent the medialization of the joint line in arthritic glenoid with multiplanar glenoid deformity. Bone and metal augmentation provided satisfactory clinical outcomes. Bone graft resorption in BIO-RSA patient raise concern about the risk of baseplate loosening and requires further long term studies.

Total Shoulder Arthroplasty in Patients with a B2 Glenoid Addressed with Corrective Reaming: Mean 8-year Follow-up.

The management of Walch B2 glenoid deformities in primary glenohumeral osteoarthritis is frequently debated. Previous literature has shown that the treatment of B2 glenoids with high-side reaming and anatomic total shoulder arthroplasty (TSA) perform well in the short-term, but is associated with an increased glenoid component failure rate in severe deformities. Therefore, many have explored alternative options, including augmented anatomic glenoid components and reverse shoulder arthroplasty. Our goal in this study is to provide mid-term radiographic and clinical outcomes after high-side reaming and anatomic TSA for B2 glenoids. Patients were followed both clinically and radiographically. Preoperative CT scans were used for retrospective analysis of deformity. Both preoperative and postoperative VAS pain, ASES score, and SST scores were collected. Radiographs were analyzed preoperatively and postoperatively for humeral head decentering relative to the glenoid vault, immediate glenoid seating, and final glenoid peg radiolucency. Of the original cohort of 59 patients (6 now deceased) reported at a mean radiographic follow-up of 3.4 years, 34 shoulders in 33 patients with B2 glenoids (mean retroversion 18.9°, range 4°-32°) were available for follow-up at a mean of 8.6 years (range 5.5-11.2) after high-side glenoid reaming with anatomic TSA. Three (5.1%) of the original 59 shoulder were revised. At final follow-up, 3 of 30 (10.0%) shoulders had radiographic glenoid component failure, but were unrevised. Glenoid component failure was associated with worse initial glenoid component seating (mean Lazarus score 1.2 vs. 2.0, p=0.002). Glenoid failure was also associated with increased posterior humeral head subluxation at 2-4 year follow-up (mean 5.6% vs 12.6%, p=0.045) and at final follow-up (mean 7.0% vs. 21%, p=0.002). There was no association between glenoid component failure and preoperative retroversion, inclination, or humeral head subluxation (all p>0.05). Glenoid component failure was associated with worse ASES (88 vs. 73) and VAS pain (0.8 vs. 2.1) scores (both p=0.03). At a mean of 8.6 years, 88% of shoulders available for follow-up had well-fixed glenoid components. Glenoid component failure was associated with poor initial glenoid component seating, with failed components having an average of 25% of the glenoid component not seated. Preoperative deformity such as glenoid retroversion, inclination, or humeral head subluxation did not predict glenoid component failure. This study supports that initial glenoid component seating and recurrence of posterior humeral head subluxation may be the most important factors for mid-term glenoid component survival in anatomic TSA in patients with B2 glenoids.

Factors associated with functional improvement after posteriorly augmented total shoulder arthroplasty.

Posteriorly augmented glenoid components in anatomic total shoulder arthroplasty (TSA) address posterior glenoid bone loss with inconsistent results. The purpose of this study was to identify preoperative and postoperative factors that impact range of motion (ROM) and function after augmented TSA in patients with type B2 or B3 glenoid morphology. This was a retrospective review of all patients who underwent TSA with a step-type augmentation performed by a single surgeon between 2009 and 2018. Patients with Walch type B2 or B3 glenoids were included. Outcomes included forward elevation (FE), external rotation (ER), internal rotation (IR), Single Assessment Numeric Evaluation (SANE) score, and visual analog scale pain score. Preoperative imaging was reviewed to assess glenoid retroversion and posterior humeral head subluxation relative to the scapular body and midglenoid face. Postoperative measurements included glenoid retroversion, subluxation relative to the scapular body, subluxation relative to the central glenoid peg, and center-peg osteolysis. Measurements were performed by investigators blinded to ROM and functional outcome scores. Fifty patients (mean age, 68.1±8.0 years) with a mean follow-up period of 42.0 months (range, 24-106 months) were included. Glenoid morphology included type B2 glenoids in 41 patients and type B3 glenoids in 9. One patient had center-peg osteolysis, and 1 patient had glenoid component loosening. Average preoperative FE, ER, and IR were 110°, 21°, and S1, respectively. Average postoperative FE, ER, and IR were 155°, 42°, and L1, respectively. The mean postoperative visual analog scale score was 0.5±0.8, and the mean SANE score was 94.5±5.6. Type B3 glenoids were associated with better postoperative IR compared with type B2 glenoids (T10 vs. L1, P=.024), with no other differences in ROM between the glenoid types. Preoperative glenoid retroversion did not significantly impact postoperative ROM. Postoperative glenoid component retroversion and residual posterior subluxation relative to the scapular body or glenoid face did not correlate with ROM in any plane. However, posterior subluxation relative to the glenoid face was moderately associated with lower SANE scores (r=-0.448, P=.006). Patients achieved excellent functional outcomes and pain improvement after TSA with an augmented glenoid component. Postoperative ROM and function showed no clinically important associations with preoperative or postoperative glenoid retroversion or humeral head subluxation in our cohort of posteriorly augmented TSAs, except for worse functional scores with increased humeral head subluxation in relation to the glenoid surface.

Serial 3D CT analysis of humeral head alignment in relation to glenoid correction and outcomes after total shoulder arthroplasty

Posterior humeral head (HH) subluxation after anatomic total shoulder arthroplasty (aTSA) is associated with worse outcomes, but it is unclear how corrective glenoid reaming correlates with HH alignment and whether HH alignment changes over time. Therefore, it was aimed to analyze the relationship between HH alignment and the scapula following aTSA to identify anatomic andsurgical factors that contribute to realignment of the HH, glenoid loosening, and clinical outcomes. Three-dimensional scapulohumeral alignment was assessed on three-dimensionally reconstructed computed tomography scans of 23 patients: preoperative (T0), 2 years post-aTSA (T1), and ≥5 years post-aTSA (T2). Anterior-posterior (AP), superior-inferior (SI), and medial-lateral offset measures of the HH center to the scapula were referenced to the HH diameter (scapulohumeral subluxation index). Glenoid version and inclination were measured at T0 and T1. Central peg osteolysis, rotator cuff fatty infiltration, and vault perforation were assessed on two-dimensional computed tomography. Relative Constant Score at T2 measured clinical outcome. Glenoid correction correlated strongly with AP and SI position of the HH (r=0.733 and r=0.797, respectively). Each degree of retroversion correction resulted in 0.9% AP scapulohumeral subluxation index offset change toward anterior. Each degree of inclination correction to superior resulted in a 1.0% offset change toward superior. A gradual postoperative proximal (mean difference [MD],-3%; P=.019), anterior (MD, 2%; P=.025), and medial (MD, 3 mm; P<.001) HH migration was observed. Asymmetric progressive rotator cuff fatty infiltration was associated with the direction of change in AP alignment over time (odds ratio, 2.04; P=.046), with progressive subscapularis fatty infiltration as the primary factor associated with gradual anterior HH translation (odds ratio, 15.61; P=.028). Gradual HH medialization was an indicator of glenoid components at risk for loosening (difference between medians, 4 mm; P=.003). Osteolysis around the central glenoid peg was influenced by overcorrection of glenoid version (MD, 7°; P=.038). Preoperative glenoid inclination was the sole anatomical or surgical factor predicting clinical outcome, as larger inferior inclination at T0 was associated with worse relative Constant Score at T2 (P=.016). Corrective glenoid reaming was an effective surgical technique to correct HH alignment in the AP and SI direction. Gradual anterior HH translation after aTSA was associated with progressive subscapularis fatty infiltration, and substantial HH medialization was an important indicator for potential glenoid loosening. While postoperative glenoid version and AP HH alignment were important for radiographic outcome, preoperative glenoid inclination predicted clinical outcome, as larger preoperative inferior inclination resulted in worse clinical scores.

Outpatient total shoulder arthroplasty in the ambulatory surgery center: a comparison of early complications in patients with and without glenoid bone loss

The purpose of this study is to compare the 90-day complications and readmission rates between patients undergoing total shoulder arthroplasty (TSA) in an ambulatory surgery center (ASC) with glenoid bone loss requiring an augmented glenoid component compared to patients without bone loss. This is a retrospective cohort study of patients undergoing outpatient TSA at an ASC (2018-2021). Readmission, direct transfer, and complications were recorded. Major and minor complications were compared. Secondary outcomes included operative time, estimated blood loss, range of motion, and patient-reported outcome measures. There were 44 patients (45 shoulders) included in the study, 20 with augmented implants for glenoid bone loss and 25 nonaugmented with a concentric glenoid. There were no statistical differences in demographics. Two complications were seen in both the augmented and nonaugmented groups (10% vs. 8%). There were no readmissions or direct transfers. The augmented group had significantly increased preoperative glenoid retroversion (23° vs. 9°, P<.05), posterior humeral head subluxation (78% vs. 61%., P<.05), and longer operative time (124.4 min vs. 112.3 min., P<.05). Patient-specific instrumentation was used in 60% of augmented cases and 29% of nonaugmented cases. There was no significant difference in complications, direct transfers, or readmissions between patients with and without glenoid bone loss being treated in an outpatient ASC. The augmented group had significantly worse preoperative deformities, longer operative times, and increased utilization of patient-specific instrumentation. Outpatient TSA in the setting of glenoid bone loss requiring augmentation was found to be safe and effective at a stand-alone ASC.

The association between anterior shoulder joint capsule thickening and glenoid deformity in primary glenohumeral osteoarthritis.

Anterior shoulder joint capsule thickening is typically present in osteoarthritic shoulders, but its association with specific patterns of glenoid wear is incompletely understood. We sought to determine the relationship between anterior capsular thickening and glenoid deformity in primary glenohumeral osteoarthritis. We retrospectively identified 134 consecutive osteoarthritic shoulders with magnetic resonance imaging and computed tomography scans performed. Axial fat-suppressed magnetic resonance imaging slices were used to quantify the anterior capsular thickness in millimeters, measured at its thickest point below the subscapularis muscle. Computed tomography scans were used to classify glenoid deformity according to the Walch classification, and an automated 3-dimensional software program provided values for glenoid retroversion and humeral head subluxation. Multinomial and linear regression models were used to characterize the association of anterior capsular thickening with Walch glenoid type, glenoid retroversion, and posterior humeral head subluxation while controlling for patient age and sex. The anterior capsule was thickest in glenoid types B2 (5.5mm, 95% confidence interval [CI]: 5.0-6.0) and B3 (6.1mm, 95% CI: 5.6-6.6) and thinnest in A1 (3.7mm, 95% CI: 3.3-4.2; P<.001). Adjusted for age and sex, glenoid types B2 (odds ratio: 4.4, 95% CI: 2.3-8.4, P<.001) and B3 (odds ratio: 5.4, 95% CI: 2.8-10.4, P<.001) showed the strongest association with increased anterior capsule thickness, compared to glenoid type A1. Increased capsular thickness correlated with greater glenoid retroversion (r=0.57; P<.001) and posterior humeral head subluxation (r=0.50; P<.001). In multivariable analysis, for every 1-mm increase in anterior capsular thickening, there was an adjusted mean increase of 3.2° (95% CI: 2.4-4.1) in glenoid retroversion and a 3.8% (95% CI: 2.7-5.0) increase in posterior humeral head subluxation. Increased thickening of the anterior shoulder capsule is associated with greater posterior glenoid wear and humeral head subluxation. Additional research should determine whether anterior capsular disease plays a causative role in the etiology or progression of eccentric glenohumeral osteoarthritis.

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.

Glenoid bone loss in anatomic total shoulder arthroplasty (aTSA) remains a controversial and challenging clinical problem. Previous studies have shown high rates of glenoid loosening for aTSA in shoulders with retroversion, posterior bone loss, and posterior humeral head subluxation. This study is the first to present minimum 2-year follow-up data of an all-polyethylene, biconvex augmented anatomic glenoid component for correction of glenoid retroversion and posterior humeral head subluxation. This study is a multicenter, retrospective review of prospectively collected data on consecutive patients from 7 global clinical sites. All patients underwent aTSA using the biconvex posterior augmented glenoid (PAG). Inclusion criteria were preoperative computed tomographic (CT) scan, minimum 2 years since surgery, preoperative and minimum 2-year postoperative range of motion examination, and patient-reported outcome measures (PROMs). Glenoid classification, glenoid retroversion, and posterior humeral head subluxation were measured from preoperative CT and radiography and postoperative radiography. Statistical comparisons between pre- and postoperative values were performed with a paired t test. Eighty-six of 110 consecutive patients during the study period (78% follow-up) met the inclusion criteria and were included in our analysis. Mean follow-up was 35±10 months, with a mean age of 68±8 years (range 48-85). Range of motion statistically improved in all planes from pre- to postoperation. Mean visual analog scale score improved from 5.2 preoperation to 0.7 postoperation, Single Assessment Numeric Evaluation score from 43.2 to 89.5, Constant score from 41.8 to 76.9, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score from 49.8 to 86.7 (all P<.0001). Mean glenoid retroversion improved from 19.3° to 7.4° (P<.0001). Posterior subluxation improved from 69.1% to 53.5% and posterior decentering improved from 5.8% to -3.0% (P<.0001). There was 1 patient with both a prosthetic joint infection and radiographic glenoid loosening that required revision. Seventy-nine of 86 patients had a Lazarus score of 0 (no radiolucency seen about peg or keel) at final follow-up. This study shows that at minimum 2-year follow-up, a posterior-augmented all-polyethylene glenoid can correct glenoid retroversion and posterior humeral head subluxation. Clinically, there was significant improvement in both range of motion and PROMs.

Paper 06: The Natural History of Nonoperative Treatment of Posterior Instability in a High Demand Population

Objectives:Nonoperative management of posterior shoulder instability is common, however there is limited data available to assess the pathomorphology of nonoperative management. The purpose of this study is to evaluate glenohumeral pathomorphology in shoulders with posterior glenohumeral instability treated nonoperatively.Methods:We conducted a retrospective review of a consecutive series of patient with isolated posterior shoulder instability defined as an isolated posterior labral tear with a corresponding positive Jerk or Kim test. Patients were excluded if they had prior shoulder surgery or absence of a Jerk or Kim test. Non-operative management was defined as a trial of formal physical therapy pursuit of nonsurgical modalities for a minimum 6 months. Patients who underwent non-operative management and subsequently had a repeat MRI of the initially injured shoulder were identified, and the two studies were compared to evaluate for changes in glenoid bone loss, glenoid morphology, cartilage injuries, and the presence of concurrent pathology. Our primary outcome was glenoid changes associated with failure of non-operative management, which was defined as reoperation and/or medical separation from the military due to the injured shoulder. Secondary outcomes included evaluation of potential risk factors for failure of non-operative management including glenoid bone loss, glenoid version, and posterior humeral head subluxation. Continuous variables were compared with student’s t-test or Fisher exact test when appropriate. Categorical variables were analyzed using Chi-squared. Multivariable regression analysis was used to evaluate risk factors for failure.Results:42/90 (46.7%) patients failed a 6-month trial of nonoperative management after being diagnosed with posterior glenohumeral instability and went onto receive an arthroscopic stabilization procedure. The failure group demonstrated a significantly greater humeral head subluxation ratio than the cohort of patients who survived nonoperative management (0.65 ± 0.2 vs 0.62 ± 0.2; p = 0.0375). Of those who failed nonoperative management only 17 had repeat MRI’s for comparison with initial MRI’s, which revealed a significantly greater increase in glenoid bone loss (6.54 ± 1.59 vs 2.68 ±1.71; p = 0.00274). The mean time from index MRI and repeat MRI was 488 days (95% CI 317 to 658).Conclusions:In patients that underwent 6-months of nonoperative management for isolated posterior glenohumeral instability, failure occurred approximately 47% of the time and was associated with a greater posterior humeral head subluxation ratio on index MRI than those who did not fail. Additionally, those who had repeat MRI on average 1.3 years later demonstrated greater glenoid bone loss when compared to the index MRI.

Scapular Y: the forgotten radiograph in glenohumeral arthritis—novel measurement of posterior humeral head subluxation on scapular Y radiographs

BackgroundAxillary radiographs, 2-dimensional (2D) axial computed tomography (CT) scans, and 3-dimensional (3D) software are described to quantify posterior humeral head subluxation (PHHS) in patients with glenohumeral arthritis (GHOA). This study’s purpose was to compare a novel method of PHHS calculated from upright scapular Y radiographs and compare it to legacy measures of PHHS on axillary radiographs, 2D CT, and 3D CT in patients with Walch type B glenoid morphology. MethodsPatients undergoing anatomic total shoulder arthroplasty for primary GHOA with Walch B glenoids and a full series of preoperative radiographs and 2D and 3D CT scans were retrospectively identified. Three fellowship-trained shoulder surgeons independently measured the percentages of PHHS on axillary and scapular Y radiographs and axial 2D CT. PHHS on 3D CT was measured volumetrically using surgical templating software. ResultsThirty patients were identified with GHOA undergoing anatomic total shoulder arthroplasty. There were 26 type-B2 (86.7%) glenoids, 3 type-B1 (10%) glenoids, and 1 type-B3 (3.3%) glenoid. The mean PHHS value for the entire group on the scapular Y radiographs was 77.0% ± 13.8%, axillary radiographs was 77.3% ± 8.6%, 2D CT was 74% ± 5.6%, and 3D CT was 83.3% ± 6.0%. PHHS on 3D CT was 6% greater than that on scapular Y (P = .04) and axillary (P < .01) radiographs and 9% greater than that on 2D CT (P < .0001). Correlation between scapular Y PHHS and all other imaging modalities was weak (axillary radiograph, r = 0.369; 2D CT, r = 0.097; 3D CT, r = 0.134). Correlation between axillary radiograph PHHS was moderate for 2D CT (r = 0.518) and weak for 3D CT (r = 0.398). Correlation of 2D CT PHHS to volumetric 3D CT was strong (r = 0.754). Excellent inter-rater reliability for a single measure between raters was observed on scapular Y radiographs (intraclass correlation coefficient; ICC = 0.922), and moderate inter-rater reliability was observed on axillary radiographs (ICC = 0.680) and 2D CT (ICC = 0.692). ConclusionScapular Y radiographs provide a novel, reliable method to measure PHHS. The weak-to-moderate correlation between scapular Y and other imaging modalities (axillary radiographs and 2D and 3D CTs) may be related to the dynamic position of the humeral head in the supine vs. upright position. Taken along with the axillary radiograph, the scapular Y radiograph provides a more comprehensive understanding of subluxation. With an increasing focus on reducing cost, utilizing the scapular Y method provides another objective measure of PHHS. Surgeons should be aware that PHHS on volumetric 3D CT was 9% greater than that on 2D CT and 6% greater than that on axillary or scapular Y radiographs.

Arthroscopic Removal of the Polyethylene Glenoid Component After Total Shoulder Arthroplasty: A Systematic Review

To identify prior studies of arthroscopic glenoid component removal after total shoulder arthroplasty (TSA) and understand indications, techniques and patient outcomes. A search of the English language literature on arthroscopic removal of the glenoid component (ARGC) after TSA published between 2005 and 2021 was performed from MEDLINE and EMBASE databases. Articles with ARGC after TSA were identified and we recorded article characteristics as well as patient demographics and outcomes contained within the studies. A total of six publications (two case reports and four retrospective case series) detailing the outcome of ARGC performed on twenty-five shoulders were identified. The average time from index procedure to glenoid removal was 117 months and mean age at time of ARGC was 75 years. Although patient reported outcomes measures (PROMs) varied in type and reporting style, all articles reported improvements in PROMs. Twenty patients in this systematic review were evaluated for post-operative complications and the complication rate was found to be 15% (n = 3). There were 2 cases (18%) of superior migration of the humeral head relative to the glenoid and no reported cases of anterior or posterior humeral head subluxation. Two of 25 patients (8%) underwent subsequent open revision procedures. The limited number of publications in this systematic review demonstrates that ARGC after TSA can result in improvements in both pain and PROMs. This less-invasive arthroscopic technique may be an alternative to open revision for lower demand patients; however, future prospective, comparative studies are necessary to better define indications.

Encouraging outcomes of stemless ceramic head anatomic shoulder arthroplasty in severe primary osteoarthritis (Walch type B glenoids).

Background: We report the radiological and functional outcomes at five years in patients with severe osteoarthritis of the glenohumeral joint and a Walch type B glenoid who have undergone stemless anatomic total shoulder replacement. Methods: A retrospective analysis of case notes, computed tomography scans and plain radiographs of patients undergoing anatomic total shoulder replacement for primary glenohumeral osteoarthritis were performed. Patients were grouped by the severity of their osteoarthritis using the modified Walch classification, glenoid retroversion and posterior humeral head subluxation. An evaluation was made using modern planning software. Functional outcomes were assessed using the American shoulder and elbow surgeons score, shoulder pain and disability index and visual analogue scale. Annual Lazarus scores were reviewed as regard to glenoid loosening. Results: Thirty patients were reviewed at 5 years. Analysis of all patient-reported outcome measures demonstrated significant improvement at 5-year review, American shoulder and elbow surgeons (p = <0.0001), shoulder pain and disability index (p = 0.0001), visual analogue scale (p = 0.0001). Radiological associations between Walch scores and Lazarus scores were not statistically significant (p = 0.1251) at 5 years. There were no associations between features of glenohumeral osteoarthritis and patient-reported outcome measures. Discussion: The severity of osteoarthritis did not show any association with glenoid component survivorship or with patient-reported outcome measures at 5 years review. Level of evidence: IV.

Radiographic Severity May Not be Associated with Pain and Function in Glenohumeral Arthritis.

Despite the routine use of plain radiographs to stratify the severity of glenohumeral osteoarthritis, little is known about the relationship between radiographic measures and patient-perceived pain and function. (1) What radiographic findings are associated with worse pain and function in patients with glenohumeral osteoarthritis? (2) What demographic factors are associated with worse pain and function in patients with glenohumeral osteoarthritis? This retrospective study included patients presenting for an initial office visit for primary glenohumeral osteoarthritis. Patients with other concurrent shoulder pathologic findings, prior surgery, lack of pain and functional scores, recent injection, or inadequate radiographs were excluded. Between January 2017 and January 2019, 3133 patients were eligible based on these inclusion criteria; 59% (1860) had outcome assessments and 48% (893) of those had radiographs. An additional 42% (378) of those with radiographs were excluded because of other shoulder findings, recent injection, prior surgery, or inadequate radiographs, leaving 16% (515 of 3133) who were fully analyzed in this study. A radiographic review included the joint space width, posterior humeral head subluxation, inferior humeral head osteophyte size, cystic change, and head asphericity. Additionally, radiographic arthritis was classified according to the Walch, Samilson-Prieto, and Kellgren-Lawrence classifications by two separate reviewers. Radiographic and demographic criteria as well as the presence of psychologic or mental illness were correlated with VAS Pain (range 1-10; minimal clinically important difference [MCID] 1.6), American Shoulder and Elbow Surgeons (ASES; range 0-100; MCID 13.6), Single Assessment Numeric Evaluation (SANE; range 0-100; MCID 14), and Simple Shoulder Test (SST; range 0-12; MCID 1.5) scores using univariate and multivariable regression analyses. After accounting for age, gender, and psychologic illness in the multivariable analysis, we found that patients with Samilson-Prieto Grade 4 arthrosis had lower VAS Pain scores (β = -1.9; p = 0.02) than those with Grade 0 or 1 did; however, no clinically important associations were found between Samilson-Prieto Grade 4 and ASES (β = 7; p = 0.25), SANE (β = 4; p = 0.63), or SST (β = 0.5; p = 0.62) scores. No clinically important associations were found between Kellgren-Lawrence Grade 3 and VAS Pain (β = 1.4; p = 0.10), ASES (β = -8; p = 0.22), SANE (β = -13; p = 0.11), or SST scores (β = 0.4; p = 0.66). Radiographic joint space and posterior subluxation also did not have any clinically important associations with VAS Pain or functional scores. In assessing Walch glenoid type, there was no clinically important association between glenoid type and VAS Pain (F = 3.1; p < 0.01), ASES (F = 1.9; p = 0.15), SANE (F = 0.45; p = 0.66), or SST scores (F = 0.76; p = 0.71). Men had higher SST scores than women did (β = 2.0; p < 0.01), but there were no clinically important differences in VAS Pain (β = -0.4; p = 0.04), ASES (β = 6; p < 0.01), or SANE (β = 4; p = 0.07) scores. No clinically important association was found between age or the presence of any psychologic illness and VAS Pain or functional scores. In patients with glenohumeral arthritis, no consistent clinically important differences in pain or function were discovered with respect to radiographic or demographic factors. Surgeons should understand that the pain levels of patients with glenohumeral arthritis may not parallel radiographic severity. Future studies can build on these findings by examining other non-radiographic or demographic factors that affect pain in patients with shoulder arthritis, such as psychological factors. Level III, prognostic study.

Radiologic midterm results of cemented and uncemented glenoid components in primary osteoarthritis of the shoulder: a matched pair analysis.

Cemented all-polyethylene glenoid components are considered the gold standard in anatomic shoulder arthroplasty. New designs of cementless metal backed glenoid components showed promising early and midterm results. The aim of this matched-pair analysis was to compare the radiologic results of two cemented glenoid components and a cementless glenoid component in patients with primary osteoarthritis (OA). Sixty shoulders were clinically and radiologically evaluated after a mean follow-up of 59months. Mean patient age was 70.4years at surgery. Based on the design of the glenoid component (keel, peg, MB), 3 groups with, respectively, 20 shoulders were formed according to the matching criteria time of follow-up, patient age and gender. RLL and osteolysis in anteroposterior and axillary X-ray images were quantified and combined in a radiologic score (R-Score). Higher scores expressed worse radiologic outcomes. Further radiological parameters such as lateral glenohumeral offset (LGHO) and subluxation index were measured according to Walch. The functional results were documented using the age and gender normalized Constant-Murley score. Postoperative R-Score was highest in pegged components (peg: 5.7, keel: 2.4, MB: 1.6; p < 0.001) when combining both radiographs and after separate analysis of anteroposterior radiographs. MB glenoids had the lowest R-score in axillary radiographs (peg: 2.2, keel: 1.4, MB: 0.6; MB vs. keel: p = 0.004, MB vs peg: p < 0.001). RLL were more common (p = 0.004) and severe (p = 0.005) in pegged glenoids (RLL incidence: 77.8%, RLL-score: 2.5) than in MB glenoids (RLL incidence: 30%, RLL-score 0.7) and tended (p = 0.084) to have a higher RLL-score than keeled glenoids (RLL incidence: 63.2%, RLL-score:1.4). Both the osteolysis score (keel vs. peg: p < 0.001, MB vs. peg p < 0.001) and the incidence of osteolysis (keel vs. peg: p = 0.008, MB vs peg: p = 0.003) were significant higher in pegged glenoids (peg: osteolysis score: 3.2, osteolysis incidence: 100%; keel: osteolysis score: 1.0, osteolysis incidence: 63.2%, MB: osteolysis score: 0.9, osteolysis incidence: 60%), while the osteolysis score in axillary images was lowest for MB glenoids (peg: 1.2, keel: 0.9, MB: 0.4; peg vs. MB: p = 0.009, keel vs. MB: p = 0.047). Osteolysis in the central axillary zone was least common in MB glenoids (peg: 50%, keel: 47.4%, MB: 15%; peg vs. MB p = 0.035, keel vs. MB p = 0.041). LGHO was highest in MB glenoids (peg: 54.1, keel: 54.5, MB: 57.8; p < 0.001) but did not increase radiographic loosening (r = 0.007; p = 0.958). Preoperative posterior humeral head subluxation seemed to affect incidence of RLL negatively (pre-op posterior decentered 64.3%, pre-op centered 31.9%; p = 0.201) but did not reach statistical significance. Pegged glenoid components had a concerning rate of RLL and osteolysis. MB glenoid components had a better outcome in axillary radiographs concerning RLL and osteolysis. Increased LGHO did not increase radiographic loosening. Retrospective comperative treatment study Level III.

Severe erosive lesion of the glenoid in gouty shoulder arthritis: a case report and review of the literature

BackgroundGout is a metabolic disease characterized by recurrent episodes of acute arthritis. Gout has been reported in many locations but is rarely localized in the shoulder joint. We describe a rare case of gouty arthritis involving bilateral shoulder joints and leading to severe destructive changes in the right shoulder glenoid.Case presentationA 62-year-old male was referred for pain and weakness in the right shoulder joint for two years, and the pain had increased in severity over the course of approximately nine months. A clinical examination revealed gout nodules on both feet and elbows. A laboratory examination showed a high erythrocyte sedimentation rate (ESR), high levels of C-reactive protein and hyperuricemia, and an imaging examination showed severe osteolytic destruction of the right shoulder glenoid and posterior humeral head subluxation. In addition, the left humeral head was involved and had a lytic lesion. Because a definite diagnosis could not be made for this patient, a right shoulder biopsy was performed. The pathological examination of the specimen revealed uric acid crystal deposits and granulomatous inflammation surrounding the deposits. After excluding infectious and neoplastic diseases, the patient was finally diagnosed with gouty shoulder arthritis.ConclusionsGout affecting the bilateral shoulder joints is exceedingly uncommon, and to our knowledge, severe erosion of the glenoid has not been previously reported. When severe erosion is present, physicians and orthopedic surgeons should consider gouty shoulder arthritis according to previous medical history and clinical manifestations.

Posterior Open-wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-free, J-shaped Iliac Crest Bone Graft in Atraumatic Posterior Instability with Pathologic Glenoid Retroversion and Dysplasia: A Preliminary Report.

Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery. In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up? Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care. In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned. In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures. Level IV, therapeutic study.

The Evolution of the Walch Classification for Primary Glenohumeral Arthritis.

Our understanding of the pathology of and treatment for glenohumeral arthritis (GHA) has grown dramatically in the past few decades. Original observations regarding patterns of glenoid erosion, glenoid retroversion, and posterior humeral head subluxation in patients with primary GHA were documented in the 1980s and early 1990s. In the late 1990s, Walch et al proposed what is now the most widely used classification system to describe the characteristic pathology of GHA. Improved understanding of both premorbid and pathologic anatomies, along with advancements in imaging, have steered modifications in this classification system. These changes have improved its reliability and helped to further guide management decisions. The purpose of this article is to review the evolution of the Walch classification, understand the rationale behind the modifications, and discuss potential future developments.

Does the Walch type B shoulder have a transverse force couple imbalance? A volumetric analysis of segmented rotator cuff muscles in osteoarthritic shoulders.

The etiology of the Walch type B shoulder remains unclear. We hypothesized that a scapulohumeral muscle imbalance, due to a disturbed transverse force couple (TFC) between the anterior and posterior rotator cuff muscles, may have a role in the pathogenesis of the type B morphology. The purpose of this study was to determine whether there is a TFC imbalance in the Walch type B shoulder using an imaging-based 3-dimensional (3D) volumetric and fatty infiltration assessment of segmented rotator cuff muscles. Computed tomography images of 33 Walch type A and 60 Walch type B shoulders with the complete scapula and humerus including the distal humeral epicondyles were evaluated. The 3D volumes of the entire subscapularis, supraspinatus, and infraspinatus-teres minor (Infra-Tm) were manually segmented and analyzed. Additionally, anthropometric parameters including glenoid version, glenoid inclination, posterior humeral head subluxation, and humeral torsion were measured. The 3D muscle analysis was then compared with the anthropometric parameters using the Wilcoxon rank sum and Kruskal-Wallis tests. There were no significant differences (P > .200) in muscle volume ratios between the Infra-Tm and the subscapularis in Walch type A (0.93) and type B (0.96) shoulders. The fatty infiltration percentage ratio, however, was significantly greater in type B shoulders (0.94 vs. 0.75, P < .001). The Infra-Tm to subscapularis fatty infiltration percentage ratio was significantly larger in patients with >75% humeral head subluxation than in those with 60%-75% head subluxation (0.97 vs. 0.74, P < .001) and significantly larger in patients with >25° of retroversion than in those with <15° of retroversion (1.10 vs. 0.75, P = .004). The supraspinatus fatty infiltration percentage was significantly lower in Walch type B shoulders than type A shoulders (P = .004). Walch type A shoulders had mean humeral retrotorsion of 22° ± 10° whereas Walch type B shoulders had humeral retrotorsion of only 14° ± 9° relative to the epicondylar axis (P< .001). The TFC is in balance in the Walch type B shoulder in terms of 3D volumetric rotator cuff muscle analysis; however, the posterior rotator cuff does demonstrate increased fatty infiltration. Posterior humeral head subluxation and glenoid retroversion, which are pathognomonic of the Walch type B shoulder, may lead to a disturbance in the length-tension relationship of the posterior rotator cuff, causing fatty infiltration.

Arthroscopic Posterior Glenoid Reconstruction Using a Fresh Distal Tibia Allograft for Recurrent Posterior Instability

Posterior glenohumeral instability is a relatively uncommon cause of shoulder instability. Recurrent posterior instability with static posterior humeral head subluxation is often associated with critical glenoid bone loss. Unlike anterior instability, the amount of bone loss for posterior instability that requires surgical reconstruction remains a topic of debate. Several techniques have been described to treat critical bony defects in patients with recurrent posterior shoulder instability with the use of both autografts and allografts depending on the amount of bone loss present. Open posterior glenoid bone block procedure is associated with increased risk of complications and morbidity to the patient. As such, all-arthroscopic techniques have emerged with the advantage of allowing for the diagnosis and treatment of concomitant glenohumeral pathology and minimizing soft-tissue dissection through the posterior deltoid and rotator cuff muscles. Reported short-term outcomes of arthroscopic posterior bone block stabilization are promising; however, it remains a technically challenging procedure due to intra-articular graft insertion and subsequent fixation congruent to the posterior glenoid articular margin. We describe an all-arthroscopic technique using a fresh distal tibia allograft fixation using 2 partially threaded screws in conjunction with an arthroscopic Latarjet fixation set for a patient with recurrent posterior shoulder instability and associated glenoid bone loss.