Anatomic and reverse shoulder arthroplasty for management of type B2 and B3 glenoids: a matched-cohort analysis.

BACKGROUND: Severe glenohumeral osteoarthritis (GHOA) with posterior glenoid erosion remains challenging to address for shoulder surgeons. Whereas anatomic total shoulder arthroplasty (TSA) has historically been the treatment of choice, reverse shoulder arthroplasty (RSA) offers an alternative option. Limited evidence exists directly comparing these 2 treatments in a similar patient population. The purpose of this study was to compare the clinical outcomes of patients with GHOA and Walch type B2 and B3 glenoid morphologies treated with TSA vs. RSA. METHODS: We performed a multicenter retrospective cohort study of patients with GHOA who were treated with primary shoulder arthroplasty and had a minimum follow-up period of 2 years. Preoperative computed tomography was used to determine type B2 and B3 glenoid morphology as described by the modified Walch classification. Three-dimensional perioperative planning software was used to characterize glenoid retroversion and humeral subluxation. Patients were categorized based on type of arthroplasty (TSA or RSA) and were matched 1:1 by sex, Walch classification, and age. Patient-reported outcome measures, active range of motion, presence and severity of glenoid loosening, and complications were compared. The percentage of patients who reached previously established clinically significant thresholds of the minimal clinically important difference and substantial clinical benefit for the American Shoulder and Elbow Surgeons score was also comparatively assessed. RESULTS: In total, 202 patients (101 per group) with GHOA and type B2 or B3 glenoids were included in the 1:1 matched analysis. The mean length of follow-up (± standard deviation) was 39 ± 18.7 months. The cohorts were well matched, with no differences in sex, age, American Society of Anesthesiologists score, body mass index, preoperative glenoid morphology (Walch classification), glenoid retroversion, or posterior subluxation (P > .05). RSA was associated with a lower postoperative visual analog scale pain score (0.5 in RSA group vs. 1.2 in TSA group, P = .036); however, no other no other significant differences in patient-reported significant differences in patient-reported outcome measures were found. Most patients in both groups (95.0% in TSA group vs. 98.0% in RSA group, P = .436) reached the minimal clinically important difference, and 82% of TSA patients and 90% of RSA patients reached the substantial clinical benefit value (P = .292). No significant differences in the overall complication rate (P = .781) and active range of motion were found, with the exception of internal rotation (scored on a numeric scale) being worse in the RSA group (2.7 preoperatively and 5.2 postoperatively in RSA group vs. 3.9 and 6.5, respectively, in TSA group; P < .001). Baseplate loosening occurred in 2 RSA cases, and 29 TSA cases had glenoid radiolucencies (P < .001), with 3 grossly loose glenoid components. CONCLUSION: Primary RSA results in short-term outcomes largely comparable to those of TSA in patients with Walch type B2 or B3 glenoid morphology. Both TSA and RSA provide substantial clinical benefit to patients with significant posterior glenoid wear.

Outcomes After Anatomic and Reverse Shoulder Arthroplasty for the Treatment of Glenohumeral Osteoarthritis: A Propensity Score-Matched Analysis.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is increasingly being utilized for the treatment of primary osteoarthritis. However, limited data are available regarding the outcomes of RSA as compared with anatomic total shoulder arthroplasty (TSA) in the setting of osteoarthritis. METHODS: We performed a retrospective matched-cohort study of patients who had undergone TSA and RSA for the treatment of primary osteoarthritis and who had a minimum of 2 years of follow-up. Patients were propensity score-matched by age, sex, body mass index (BMI), preoperative American Shoulder and Elbow Surgeons (ASES) score, preoperative active forward elevation, and Walch glenoid morphology. Baseline patient demographics and clinical outcomes, including active range of motion, ASES score, Single Assessment Numerical Evaluation (SANE), and visual analog scale (VAS) for pain, were collected. Clinical and radiographic complications were evaluated. RESULTS: One hundred and thirty-four patients (67 patients per group) were included; the mean duration of follow-up (and standard deviation) was 30 ± 10.7 months. No significant differences were found between the TSA and RSA groups in terms of the baseline or final VAS pain score (p = 0.99 and p = 0.99, respectively), ASES scores (p = 0.99 and p = 0.49, respectively), or SANE scores (p = 0.22 and p = 0.73, respectively). TSA was associated with significantly better postoperative active forward elevation (149° ± 13° versus 142° ± 15°; p = 0.003), external rotation (63° ± 14° versus 57° ± 18°; p = 0.02), and internal rotation (≥L3) (68.7% versus 37.3%; p < 0.001); however, there were only significant baseline-to-postoperative improvements in internal rotation (gain of ≥4 levels in 53.7% versus 31.3%; p = 0.009). The overall complication rate was 4.5% (6 of 134), with no significant difference between TSA and RSA (p = 0.99). Radiolucent lines were observed in association with 14.9% of TSAs, with no gross glenoid loosening. One TSA (1.5%) was revised to RSA for the treatment of a rotator cuff tear. No loosening or revision was encountered in the RSA group. CONCLUSIONS: When performed for the treatment of osteoarthritis, TSA and RSA resulted in similar short-term patient-reported outcomes, with better postoperative range of motion after TSA. Longer follow-up is needed to determine the ultimate value of RSA in the setting of osteoarthritis. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Predictors of poor and excellent outcomes after reverse total shoulder arthroplasty.

BACKGROUND: Favorable clinical and functional outcomes can be achieved with reverse total shoulder arthroplasty (RSA). Given the expanding utilization of RSA in the United States, understanding the factors that influence both excellent and poor outcomes is increasingly important. METHODS: A single-surgeon prospective registry was used to identify patients who underwent RSA from 2015 to 2018 with a minimum of 2 years' follow-up. An excellent postoperative clinical outcome was defined as a final American Shoulder and Elbow Surgeons (ASES) score in the top quartile of ASES scores. A poor outcome was defined as an ASES score in the bottom quartile. Logistic regression was used to determine preoperative characteristics associated with both excellent and poor outcomes. RESULTS: A total of 338 patients with a mean age of 71.5 years (standard deviation [SD], 6.4 years) met the inclusion and exclusion criteria. The average preoperative ASES score for the entire cohort was 35.3 (SD, 16.4), which improved to 82.4 (SD, 16.1) postoperatively (P < .001). Univariate analysis demonstrated that a diagnosis of primary osteoarthritis (OA), private insurance, and higher preoperative ASES scores were significantly associated with achieving excellent outcomes (P < .01 for all). Variables predictive of poor outcomes were workers' compensation status (P = .03), depression (P = .02), a preoperative diagnosis of rotator cuff tear arthropathy (P < .01), preoperative opioid use (P < .01), a higher number of allergies (P < .01), and prior ipsilateral shoulder surgery (P < .01). Multivariate regression analysis demonstrated that OA (odds ratio [OR], 5.6; 95% confidence interval [CI], 1.2-26.5; P = .03) and private insurance (OR, 2.7; 95% CI, 1.12-6.5; P = .02) correlated with excellent outcomes whereas a higher number of reported allergies (OR, 0.83; 95% CI, 0.71-0.97; P = .02), self-reported depression (OR, 0.39; 95% CI, 0.16-0.99; P =.04), a history of ipsilateral shoulder surgery (OR, 0.36; 95% CI, 0.15-0.87; P =.02), and preoperative opioid use (OR, 0.26; 95% CI, 0.09-0.76; P = .01) were predictive of poor outcomes. CONCLUSIONS: A preoperative diagnosis of primary OA is the strongest predictor of excellent clinical outcomes following RSA. Patients with an increasing number of reported allergies, self-reported depression, a history of ipsilateral shoulder surgery, and preoperative opioid use are significantly more likely to achieve poor outcomes after RSA. Given the increasing utilization of RSA, this information is important to appropriately counsel patients regarding postoperative expectations.

Rotator cuff fatty infiltration and muscle atrophy: relation to glenoid deformity in primary glenohumeral osteoarthritis.

BACKGROUND: Muscle atrophy (MA) and fatty infiltration (FI) are degenerative processes of the rotator cuff musculature that have incompletely understood relationships with the development of eccentric glenoid wear in the setting of primary glenohumeral osteoarthritis (GHOA). METHODS: All patients with GHOA and an intact rotator cuff who underwent both magnetic resonance imaging and computed tomography scans of the affected shoulder prior to total shoulder arthroplasty between 2015 and 2020 were identified from a prospectively maintained registry. Rotator cuff MA was measured quantitatively on sequential sagittal magnetic resonance images, whereas FI was assessed on sagittal magnetic resonance imaging slices using the Goutallier classification. Preoperative computed tomography scans were reconstructed using automated 3-dimensional software to determine glenoid retroversion, glenoid inclination, and humeral head subluxation. Glenoid deformity was classified according to the Walch classification. Univariate and multivariable regression analyses were performed to characterize associations between age, sex, muscle area, FI, and glenoid morphology. RESULTS: Among the 127 included patients, significant associations were found between male sex and larger overall rotator cuff musculature (P < .01), increased ratio of the posterior rotator cuff (PRC) to the subscapularis area (P = .01), and glenoid retroversion (19° vs. 14°, P < .01). Larger supraspinatus and PRC muscle size was correlated with increased retroversion (r = 0.23 [P = .006] for supraspinatus and r = 0.25 [P = .004] for PRC) and humeral head subluxation (r = 0.25 [P = .004] for supraspinatus and r = 0.28 [P = .001] for PRC). The ratio of PRC muscle size to anterior rotator cuff muscle size was not associated with evidence of eccentric glenoid wear (P > .05). After we controlled for confounding factors, increasing glenoid retroversion was associated with high-grade infraspinatus FI (ß, 6.8; 95% confidence interval, 2.9-10.7; P < .01) whereas larger PRC musculature was predictive of a Walch type B (vs. type A) glenoid (odds ratio, 1.3; 95% confidence interval, 1.0-1.5; P = .04). CONCLUSION: Patients with eccentric glenoid wear in the setting of primary GHOA and an intact rotator cuff appear to have both larger PRC musculature and higher rates of infraspinatus FI. Although the temporal and causal relationships of these associations remain ambiguous, MA and FI should be considered 2 discrete processes in the natural history of GHOA.

Variation in the Profit Margin for Different Types of Total Joint Arthroplasty.

BACKGROUND: As health care shifts to a value-based model with bundled-payment methods, it is important to understand the costs and reimbursements of arthroplasty procedures that represent the largest expenditure of Medicare. The aim of the present study was to characterize the variation in (1) total hospital costs, (2) reimbursement, and (3) profit margin for different arthroplasty procedures. METHODS: The total hospital costs of total knee arthroplasty (TKA), total hip arthroplasty (THA), anatomic total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), and total ankle arthroplasty (TAA) were calculated with use of time-driven activity-based costing at an orthopaedic institution from 2018 to 2020. The average reimbursement for each type of procedure was determined. Profit margin, defined as the reimbursement profit after direct costs, was calculated by deducting the average time-drive activity-based total hospital costs from the reimbursement value. Multivariate analyses were performed to evaluate the associations between costs, reimbursement, and profit margins. RESULTS: There were 13,545 arthroplasty procedures analyzed for this study, including 6,636 TKAs, 5,902 THAs, 346 TSAs, 577 RSAs, and 84 TAAs. Costs and reimbursement were highest for TAA. THA and TKA resulted in the highest profit margins, whereas RSA resulted in the lowest. The strongest associations with profit margin were private insurance (0.46547), age (-0.22732), and implant cost (-0.19240). CONCLUSIONS: THA and TKA had greater profit margins overall than TAA and upper-extremity arthroplasty in general. Profit margins for RSA, TSA, and TAA were all at least 28% lower than those for TKA or THA. Lower-volume arthroplasty procedures were associated with decreased profit margins. Study findings suggest that optimizing implant costs and length of stay are important for sustaining institutional fiscal health when performing shoulder and ankle arthroplasty surgery.

Primary reverse total shoulder arthroplasty performed for glenohumeral arthritis: does glenoid morphology matter?

BACKGROUND: Indications for reverse total shoulder arthroplasty (RTSA) have expanded to include primary glenohumeral osteoarthritis (GHOA) with an intact rotator cuff. Limited evidence exists on RTSA in patients with primary GHOA and no posterior glenoid wear (Walch A1, A2, and B1 morphologies). The purpose of this retrospective cohort study was to determine if glenoid morphology is associated with clinical outcomes in patients undergoing RTSA for primary GHOA. METHODS: A retrospective review of prospectively collected data was performed in patients undergoing primary RTSA for GHOA with a minimum of 2-year clinical follow-up. Preoperative computed tomography and magnetic resonance imaging were used to categorize glenoid morphology as described by the modified Walch classification. Pre- and postoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Single Assessment Numeric Evaluation (SANE), visual analog scale (VAS) pain scores, and range of motion (ROM) measurements were compared across Walch glenoid subtypes. The percentage of patients that reached previously established clinically significant thresholds for minimal clinically important difference (MCID) and substantial clinical benefit (SCB) was also comparatively assessed. Multivariable analysis was used to evaluate the association between glenoid morphology and postoperative ASES score while controlling for potentially confounding variables. RESULTS: Of the 247 consecutive patients, 197 were available at a minimum 2-year follow-up (80%). Significant improvements were seen in ASES, VAS pain, SANE, and ROM from baseline to final postoperative follow-up in the combined patient cohort (all P < .001). Most (98.0%) patients reached MCID, and 90.9% of patients reached SCB for ASES threshold. No significant differences were found among Walch subtypes in terms of preoperative to postoperative improvement in ASES (P = .39), SANE (P = .4), VAS pain (P = .49), forward elevation (P = .77), external rotation (P = .45), or internal rotation (P= 0.1). The only significant difference in postoperative outcomes between Walch glenoid subtypes was higher postoperative ASES scores among type B3 glenoids compared with type A1 glenoids (P = .03) on univariate analysis. However, no individual Walch glenoid subtype was associated with lower postoperative ASES scores on multivariable analysis (P > .05). CONCLUSION: Primary RTSA provides excellent short-term outcomes in patients with glenohumeral arthritis with intact rotator cuff, regardless of the degree of preoperative glenoid deformity. Surgeons can use these data to support the use of RTSA for glenohumeral arthritis in a more standardized way.

Clinical Outcomes After Reverse Total Shoulder Arthroplasty in Patients With Primary Glenohumeral Osteoarthritis Compared With Rotator Cuff Tear Arthropathy: Does Preoperative Diagnosis Make a Difference?

INTRODUCTION: The primary purpose of this study was to evaluate the clinical outcomes of patients who underwent reverse total shoulder arthroplasty performed for primary glenohumeral osteoarthritis (GHOA) with an intact rotator cuff compared with rotator cuff tear arthropathy (CTA). METHODS: This was a retrospective review of prospectively collected data including consecutive patients who underwent primary reverse total shoulder arthroplasty for GHOA or CTA with a minimum of 2-year follow-up. Baseline patient demographics and clinical outcomes including active range of motion, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numerical Evaluation, and visual analog scale for pain were collected. Univariate and multivariate regression analyses were performed to evaluate the effect of preoperative diagnosis on clinical outcomes. RESULTS: Patients with a preoperative diagnosis of GHOA demonstrated significantly better postoperative active forward elevation (138.6° versus 127.3°; P < 0.01), external rotation (54.2° versus 43.8°; P < 0.01), and change in internal rotation (Δ 2.1 points versus Δ 1.2 points; P < 0.01). Patients with GHOA demonstrated significantly better postoperative ASES (86.8 versus 76.6; P < 0.01), Single Assessment Numerical Evaluation (89.7 versus 78.5; P < 0.01), and visual analog scale scores (0.63 versus 1.2; P < 0.01). Minimal clinically important difference for ASES score was achieved by 97.5% of patients with GHOA compared with 86.7% of patients with CTA (P < 0.01), whereas substantial clinical benefit was achieved by 90.4% of patients with GHOA and 71.7% of patients with CTA (P < 0.01). After a multivariate linear regression analysis, postoperative ASES scores were independently associated with previous ipsilateral shoulder surgery (P = 0.042), preoperative ASES score (P = 0.01), and primary diagnosis of GHOA (P < 0.01). CONCLUSION: RTSA performed in patients with GHOA and an intact rotator cuff is associated with improved functional and clinical outcomes compared with those patients treated for CTA. LEVEL OF EVIDENCE: Level III Therapeutic Study.

Rotator cuff fatty infiltration and muscle atrophy do not impact clinical outcomes after reverse total shoulder arthroplasty for glenohumeral osteoarthritis with intact rotator cuff.

BACKGROUND: The clinical significance of rotator cuff muscle quality following reverse total shoulder arthroplasty (RTSA) remains uncertain. The purpose of this study was to evaluate the influence of rotator cuff fatty infiltration (FI) and muscle atrophy (MA) on clinical outcomes following RTSA for glenohumeral osteoarthritis (GHOA). METHODS: One hundred eight shoulders with primary GHOA that underwent RTSA with a lateralized glenosphere for GHOA with a minimum of 2-year follow-up were identified from a prospectively maintained registry. Each rotator cuff muscle was assessed on preoperative magnetic resonance imaging for FI and quantitative amount of MA. Pre- and postoperative outcomes included American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score, Single Assessment Numerical Evaluation (SANE) score, visual analog scale pain score, and range of motion (ROM) measurements. RESULTS: Eighty-one patients with a mean age of 70.7 ± 5.4 years (range: 57-85) were included who underwent RTSA with a mean follow-up of 2.1 years (range: 2-3.9 years). There was a significant improvement in all outcome measures postoperatively (P < .01). Twenty-two patients (27.1%) had moderate to severe combined infraspinatus and teres minor FI. There was no significant difference in the postoperative external rotation or clinical outcomes compared with those patients with only mild FI (P > .05). Forty-three patients (53.1%) had moderate to severe global rotator cuff FI. There was no significant difference in postoperative outcomes compared with those patients with only mild FI (P < .01). Univariate analysis did not reveal any significant association between the degree of FI or MA of any individual rotator cuff muscle and postoperative clinical outcomes or ROM. The size ratio of the posterior rotator cuff to the subscapularis muscle was positively correlated with preoperative SANE scores but negatively correlated with absolute postoperative and change in preoperative to postoperative SANE scores. However, there were no significant correlations between this size ratio and the other outcome measures. CONCLUSION: Rotator cuff muscle quality as assessed by MA and FI does not impact clinical outcomes following RTSA with a lateralized glenosphere in patients with GHOA and an intact rotator cuff.

Predictors of acromial and scapular stress fracture after reverse shoulder arthroplasty: a study by the ASES Complications of RSA Multicenter Research Group.

BACKGROUND: Acromial (ASF) and scapular spine (SSF) stress fractures are well-recognized complications of reverse shoulder arthroplasty (RSA), but much of the current data are derived from single-center or single-implant studies with limited generalizability. This study from the American Shoulder and Elbow Surgeons (ASES) Complications of Reverse Shoulder Arthroplasty Multicenter Research Group determined the incidence of ASF/SSF after RSA and identified preoperative patient characteristics associated with their occurrence. METHOD: Fifteen institutions including 21 ASES members across the United States participated in this study. Patients undergoing either primary or revision RSA between January 2013 and June 2019 with a minimum 3-month follow-up were included. All definitions and inclusion criteria were determined using the Delphi method, an iterative survey process involving all primary investigators. Consensus was achieved when at least 75% of investigators agreed on each aspect of the study protocol. Only symptomatic ASF/SSF diagnosed by radiograph or computed tomography were considered. Multivariable logistic regression was performed to identify factors associated with ASF/SSF development. RESULTS: We identified 6755 RSAs with an average follow-up of 19.8 months (range, 3-94). The total stress fracture incidence rate was 3.9% (n = 264), of which 3.0% (n = 200) were ASF and 0.9% (n = 64) were SSF. Fractures occurred at an average 8.2 months (0-64) following RSA with 21.2% (n = 56) following a trauma. Patient-related factors independently predictive of ASF were chronic dislocation (odds ratio [OR] 3.67, P = .04), massive rotator cuff tear without arthritis (OR 2.51, P < .01), rotator cuff arthropathy (OR 2.14, P < .01), self-reported osteoporosis (OR 2.21, P < .01), inflammatory arthritis (OR 2.18, P < .01), female sex (OR 1.51, P = .02), and older age (OR 1.02 per 1-year increase, P = .02). Factors independently associated with the development of SSF included osteoporosis (OR 2.63, P < .01), female sex (OR 2.34, P = .01), rotator cuff arthropathy (OR 2.12, P = .03), and inflammatory arthritis (OR 2.05, P = .03). CONCLUSION: About 1 in 26 patients undergoing RSA will develop a symptomatic ASF or SSF, more frequently within the first year of surgery. Our results indicate that severe rotator cuff disease may play an important role in the occurrence of stress fractures following RSA. This information can be used to counsel patients about potential setbacks in recovery, especially among older women with suboptimal bone health. Strategies for prevention of ASF and SSF in these at-risk patients warrant further study. A follow-up study evaluating the impact of prosthetic factors on the incidence rates of ASF and SSF may prove highly valuable in the decision-making process.