Humeral rotation osteotomy is not associated with glenohumeral and scapulohumeral decentering at long-term follow-up.

BACKGROUND: Weber rotational osteotomy that increases humeral retrotorsion in patients with anterior shoulder instability has become unpopular because of recurrence of instability and high rates of early-onset osteoarthritis (OA). However, the wear pattern in patients after rotational osteotomy remains unknown. The aim of this study was to determine the influence of surgically increased humerus retrotorsion on glenohumeral and scapulohumeral centering in a long-term follow-up. METHODS: The data of 18 shoulders in 18 patients diagnosed with a unilateral chronic recurrent anterior shoulder instability treated with an internal rotation subcapital humerus osteotomy between 1984 and 1990 were drawn from a previously published cohort and enrolled in the study. All patients had available bilateral computed tomography (CT) scans performed after a mean follow-up of 14 (12-18) years. On these CT scans a comparison of the operated and the contralateral healthy side with regard to humerus torsion, glenoid version, glenoid offset, glenohumeral and scapulohumeral subluxation indices, rotator cuff action lines, and osteoarthritic changes was performed. RESULTS: The analysis of follow-up CT scans revealed a significantly higher mean humeral retrotorsion in the operated side compared with the healthy side (41.6° ± 14.0° vs. 20.7° ± 8.2°, P < .001). No differences were found in terms of glenohumeral subluxation index (0.50 ± 0.08 vs. 0.51 ± 0.03, P = .259), scapulohumeral subluxation index (0.53 ± 0.09 vs. 0.54 ± 0.03, P = .283), glenoid version (-3.9° ± 4.6° vs. -4.1° ± 3.7°, P = .424), glenoid offset (4.0 ± 2.8 mm vs. 4.0 ± 1.3 mm, P = .484), infraspinatus action lines (102.5° ± 4.7° vs. 101.2° ± 2.1°, P = .116), subscapularis action lines (74.0° ± 6.0° vs. 73.1° ± 2.3°, P = .260), and resultant rotator cuff action lines (87.8° ± 4.9° vs. 87.0° ± 1.8°, P = .231) between operated and healthy shoulders. Osteoarthritic changes were observed in all operated shoulders and in 13 of 18 healthy shoulders. The OA grade was mild in 5 patients, moderate in 11, and severe in 2 cases for operated shoulders and mild in 13 healthy shoulders at the last follow-up. CONCLUSION: The surgical increase of humeral retrotorsion by 20°-30° did not affect glenohumeral and scapulohumeral centering in patients with a Weber rotational osteotomy after a long-term follow-up compared to the healthy side. Although a high degree of early-onset OA was observed it remains unclear whether the cause is the surgical interventions performed or the joint instability itself.

B2 and B3 glenoid osteoarthirtis: outcomes of corrective and concentric (C2) reaming of the glenoid combined with pyrocarbon hemiarthroplasty.

BACKGROUND: Posterior humeral subluxation (PHS) in B2 and 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 and painful glenoid erosion in hemiarthroplasty with metallic heads. We hypothesized that corrective and concentric (C2) reaming 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 and active patients with B2 and B3 glenoid. METHODS: Between 2014 and 2020, 41shoulders (in 35 patients, mean age of 57.9 years) underwent HA-PYC combined with C2 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, and 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 (2-9.5 years), the prosthesis survival was 95% (39 of 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 = .001), and the mean PHS from 74% to 56.5% (P = .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 < .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 < .001). Overall, 84% of active patients returned to work, and all patients returned to sports. CONCLUSION: In B2 and 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 midterm follow-up. The combined procedure results in excellent functional outcomes and high prosthesis survivorship at midterm follow-up. HA-PYC and C2 reaming of the glenoid is an alternative shoulder arthroplasty for young/active patients with type B glenoid osteoarthritis who want to return to work or sports practice.

Total Shoulder Arthroplasty is associated With Less Pain and Better Functional Outcomes, but Humeral Head Resurfacing may be Preferred in Younger, Higher Demand Patients: A Short-Term Outcomes Study in Patients with Glenohumeral Osteoarthritis.

Objectives: This study aimed to compare short-term outcomes following Total Shoulder Arthroplasty (TSA) and Humeral Head Resurfacing (HHR) in patients with glenohumeral osteoarthritis (GHOA). Methods: A retrospective analysis included patients who had undergone either TSA or HHR for GHOA at a single institution. Baseline demographics, complications, range of motion (active forward flexion, FF and active external rotation, ER), visual analog scores (VAS), and Subjective Shoulder Values (SSV) were collected. Results: A total of 69 TSA and 56 HHR patients were analyzed. More HHR patients were laborers (44% versus 21%, P=0.01). There were more smokers in the TSA group (25% versus 11%, P=0.04) and more cardiovascular disease in the HHR cohort (64% versus. 6%, p<0.0001). Postoperative FF was similar, but ER was greater in the HHR (47° ± 15°) vs. TSA group (40° ± 12°, P = 0.01). VAS was lower after TSA vs. HHR (median 0, IQR 1 versus median 3.7, IQR 6.9, p<0.0001), and SSV was higher after TSA (89% ± 13% vs. 75% ± 20% after HHR; p<0.0001). Post-operative impingement was more common after HHR (32% vs. 3% for TSA, p<0.0001). All other complications were equivalent. Conclusion: While younger patients and heavy laborers had improved ER following HHR, their pain relief was greater after TSA. Decisions on surgical technique should be based on patient-specific demographic and anatomic factors.

Computer-Assisted Navigation in Reverse Shoulder Arthroplasty: Surgical Experience and Clinical Outcomes.

Background: The primary cause of medium- to long-term complications in reverse shoulder arthroplasty (RSA) is the failure of the glenoid component. The purpose of this study was to evaluate both the achievement of planning through computer-assisted navigation and the clinical outcomes at a minimum follow-up (FU) of 12 months. Methods: From December 2019 to December 2022, 57 Equinoxe RSAs with computer-assisted navigation were performed. The average age was 72.8 ± 6.6 years. Using the Orthoblue software, the version and inclination of the glenoid were evaluated from a preoperative CT scan, and planning was performed. Intraoperative navigation data were evaluated, and the clinical outcomes were assessed at a minimum follow-up of 12 months. Results: The average follow-up was 30.7 ± 13.5 months. The planning was reproduced in all implants. No errors in the computer-assisted navigation system were detected. No intraoperative or postoperative complications were recorded. At the final FU, the average active anterior elevation was 143° ± 36°, external rotation was 34° ± 5°, QuickDASH score was 19 ± 16 points, and constant score was 77 ± 18. Conclusions: Computer-assisted navigation is a reliable system for positioning prosthetic implants on challenging glenoids. A longer follow-up period is necessary to confirm the reduction in postoperative complications and the increase in survival compared to traditional RSA.

Glenohumeral Osteoarthritis: A Biological Advantage or a Missed Diagnosis?

(1) Background: Osteoarthritis is a degenerative joint disease that is commonly diagnosed in the aging population. Interestingly, the lower extremity joints have a higher published incidence of osteoarthritis than the upper extremity joints. Although much is known about the disease process, it remains unclear why some joints are more affected than others. (2) Methods: A comprehensive literature review was conducted utilizing the search engines PubMed, Google Scholar, and Elsevier from 2014 to 2024, directing our search to osteoarthritis of various joints, with the focus being on glenohumeral osteoarthritis. (3) Results and Discussion: The literature review revealed a publication difference, which may be explained by the inconsistency in classification systems utilized in the diagnosis of shoulder osteoarthritis. For instance, there are six classification systems employed in the diagnosis of glenohumeral osteoarthritis, making the true incidence and, therefore, the prevalence unobtainable. Furthermore, susceptibility to osteoarthritis in various joints is complicated by factors such as joint anatomy, weight-bearing status, and prior injuries to the joint. (4) Conclusions: This review reveals the lack of understanding of shoulder osteoarthritis's true incidence and prevalence while considering the anatomy and biomechanics of the glenohumeral joint. In addition, this is the first paper to suggest a single criterion for the diagnosis of glenohumeral osteoarthritis.

Utility of Patient Reported Outcome Measurement Information System measures in predicting shoulder arthroplasty in patients with shoulder osteoarthritis.

BACKGROUND: The decision to treat shoulder osteoarthritis (OA) definitively with shoulder arthroplasty (SA) is multifactorial, considering objective findings, subjective information, and patient goals. The first goal of this study was to determine if Patient Reported Outcome Measurement Information System (PROMIS) measures correlated with patients with shoulder OA who underwent SA within 1 year. The second goal of this study was to determine if score cut-offs in PROMIS domains could further discriminate which shoulder OA patients underwent SA within 1 year. METHODS: This retrospective case-control study examined patients with a diagnosis of shoulder OA who consulted an orthopedic provider from November 1, 2020 to May 23, 2022, and recorded PROMIS measures in the domains of Physical Function, Depression, and/or Pain Interference. A surgical group was defined as patients who underwent SA within 1 year of the most recent PROMIS measures and the nonsurgical patients were defined as the control group. Mean PROMIS scores were compared between the surgical and control groups. Separate logistic regression models controlling for age, race, ethnicity, and comorbidity count were performed for each PROMIS domain as a 1) continuous variable, and then as 2) binary variable defined by PROMIS score cut-off points to determine which scores correlated with undergoing SA to further characterize the potential clinical utility of PROMIS score cut-offs in relating to undergoing SA. RESULTS: The surgical group of 478 patients was older (68.2 vs. 63.8 years), more often of White race (82.6% vs. 70.9%), and less often of Hispanic Ethnicity (1.5% vs. 2.9%) than the control group of 3343 patients. Using optimal cut-offs in PROMIS scores, Pain Interference ≥63 (odds ratio [OR] = 2.97 (2.41-3.64), P < .001), Physical Function ≤39 (OR = 1.81 (95% confidence interval, 1.48-2.22), P < .001), and depression ≥49 (OR = 1.82 (95% confidence interval, 1.50-2.22), P < .001) were all found to correlate with undergoing SA within 1 year in multivariable logistic regressions. CONCLUSION: The results of this study demonstrate that cut-off scores for PROMIS measures differentiated patients undergoing SA within 1 year. These cut-off scores may have clinical utility in aiding in decision-making regarding surgical candidates for SA. Further research is needed to validate these cut-off scores and determine how they relate to patient outcomes after SA.

Covariations between scapular shape and bone density in B-glenoids: A statistical shape and density modeling-approach.

B-type glenoids are characterized by posterior humeral head migration and/or bony-erosion-induced glenoid retroversion. Patients with this type of osteoarthritic glenoids are known to be at increased risk of glenoid component loosening after anatomic total shoulder arthroplasty (aTSA). One of the main challenges in B glenoid surgical planning is to find a balance between correcting the bony shape and maintaining the quality of the bone support. This study aims to systematically quantify variabilities in terms of scapular morphology and bone mineral density in patients with B glenoids and to identify patterns of covariation between these two features. Using computed tomography scan images of 62 patients, three-dimensional scapular surface models were constructed. Rigid and nonrigid surface registration of the scapular surfaces, followed by volumetric registration and material mapping, enabled us to develop statistical shape model (SSM) and statistical density model (SDM). Partial least square correlation (PLSC) was used to identify patterns of covariation. The developed SSM and SDM represented 85.9% and 56.6% of variabilities in terms of scapular morphology and bone density, respectively. PLSC identified four modes of covariation, explaining 66.0% of the correlation between these two variations. Covariation of posterior-inferior glenoid erosion with posterior sclerotic bone formation in association with reduction of bone density in the anterior and central part of the glenoid was detected as the primary mode of covariation. Identification of these asymmetrical distribution of bone density can inform us about possible reasons behind glenoid component loosening in B glenoids and surgical guidelines in terms of the compromise between bony shape correction and bone support quality.

Bilateral reverse shoulder arthroplasty versus bilateral anatomic shoulder arthroplasty: a meta-analysis and systematic review.

BACKGROUND: As the population is aging and indications are expanding, shoulder arthroplasty is becoming more frequent, especially bilateral staged replacement. However, surgeons are hesitant to use bilateral reverse prostheses due to potential limitations on activities of daily living. METHODS: This meta-analysis was conducted to compare bilateral anatomic to bilateral reverse shoulder implants. PubMed, Cochrane, and Google Scholar (pages 1-20) were searched until April 2023. The clinical outcomes consisted of postoperative functional scores (American Shoulder and Elbow Surgeons [ASES], Single Assessment Numeric Evaluation [SANE], Physical Component Score [PCS], Mental Component Score, and Simple Shoulder Test), pain, and range of motion (external rotation and forward elevation). Three studies were included in this meta-analysis. RESULTS: Bilateral anatomic implants had better postoperative functional outcomes and range of motion, but no significant difference was seen in postoperative pain when compared to the reverse prosthesis. Better ASES score, SANE score, and PCS as well as better external rotation and forward elevation were seen in the bilateral anatomic shoulder replacement group, but no significant difference in pain levels was seen between the two groups. CONCLUSIONS: The results may be explained by the lower baseline seen in the reverse prosthesis group, which may be due to an older population and different indications. Nevertheless, more randomized controlled studies are needed to confirm these findings. Level of evidence: III.

Survey of Osteoarthritis of the Shoulder in Patients who Underwent Knee Arthroplasty for Knee Osteoarthritis.

The relationship between osteoarthritis (OA) of the lower extremity and shoulder OA has not been established. This study evaluated the prevalence of shoulder OA in patients with knee OA. We collected contrast-enhanced computed tomography (CECT) images of the shoulder joints of 105 patients with knee OA that were taken 1 week after they underwent primary knee arthroplasty to check for venous thromboembolism (VTE). The images were compared with CECT images of 110 control-group patients that were taken for the purpose of differentiating VTE. Shoulder OA was present in a significantly higher percentage of patients with knee arthroplasty than controls (29% versus 15%), and the difference was particularly pronounced in patients in their 70s (33%) compared to age-matched controls (11%). Patients with knee OA often use arm support to stand up or walk due to knee joint pain and muscle weakness, which places the weight-bearing shoulder at risk of developing OA.

Assessment of Prevalence and Risk Factors for Central Sensitization Related to Shoulder Osteoarthritis and Rotator Cuff Tears Using the Central Sensitization Inventory: A Cross-Sectional Study in Shoulder Surgery Patients.

Shoulder disorders occasionally cause intractable pain. Central sensitization (CS) may be involved in such pain. Identifying risk factors associated with CS is crucial for effective pain control. This study aimed to determine the effects of shoulder osteoarthritis and rotator cuff tears (RCT) on CS and associated factors. This study included patients evaluated for CS using the Central Sensitization Inventory (CSI) before surgery for shoulder osteoarthritis, RCT, or cuff tear arthropathy. Patients with a CSI score of 40 or higher were defined as having CS. The relationships between glenohumeral osteoarthritis (GHOA), RCT size, and CS were statistically analyzed. Multiple regression analysis was performed to examine the factors affecting CSI scores. Subjects included 167 patients: 131 patients had RCT without GHOA, 23 had GHOA with RCT, and 13 had GHOA without RCT. The GHOA group had a significantly higher CSI score (27.5 [10.8-40.5] vs. 18.0 [10.0-27.5]) and CS prevalence (27.8% vs. 8.4%) than the RCT without GHOA group. There was no significant correlation between RCT size and CSI scores. Multiple regression analysis showed that female sex, severe pain, and long pain duration were associated with higher CSI scores. Considering the risk factors for CS might be helpful in shoulder treatment.

Hemiarthroplasty versus total shoulder arthroplasty in B2 glenoids with an intact rotator cuff: a long-term matched cohort analysis.

Background: Walch B2 glenoids present unique challenges to the shoulder arthroplasty surgeon, particularly in young, active patients who may wish to avoid the restrictions typically associated with an anatomic total shoulder arthroplasty (TSA). Long-term data are limited when comparing hemiarthroplasty (HA) and TSA for patients with an intact rotator cuff. The purpose of our study was to compare the long-term outcomes of HA vs. TSA in a matched analysis of patients with B2 glenoids, primary osteoarthritis (OA), and an intact rotator cuff. Methods: A retrospective review was performed of all patients who underwent HA or TSA between January 2000 and December 2011 at a single institution. Inclusion criteria were primary OA, Walch B2 glenoid morphology, an intact rotator cuff intraoperatively, at least 2 years of clinical follow-up, or revision within 2 years of surgery. Fifteen HAs met inclusion criteria and were matched 1:2 with 30 TSAs using age, sex, body mass index, and implant selection. Clinical outcomes including range of motion (ROM), visual analog scale (VAS) for pain, subjective shoulder value score, American Shoulder and Elbow Surgeons (ASES) score, complications, and revisions were recorded. Postoperative radiographs were reviewed to assess for stem loosening, humeral head subluxation, glenoid loosening, and glenoid erosion. Results: A total of 15 HAs and 30 TSAs met inclusion criteria at a mean follow-up of 9.3 years. The mean age at the time of surgery was 60.2 years for HA and 65.4 years for TSA (P = .08). Both cohorts had significant improvements in ROM, subjective shoulder value, and VAS pain scores (P < .001). TSA had higher postoperative ASES scores compared to HA (P = .03) and lower postoperative VAS pain scores (P = .03), although the decrease in pain from preoperatively to final follow-up was not significantly different between HA and TSA (P = .11). HAs were more likely to have posterior humeral subluxation (P < .001) and stem lucencies (P = .02). Revisions occurred in 11.1% of the cohort with no difference for HA and TSA (P = .73). Conclusions: At nearly 10 years of follow-up, HA and TSA both showed significant improvements in ROM and pain when performed for primary glenohumeral OA in B2 glenoids with intact rotator cuffs. Compared to HA, TSAs had less posterior humeral subluxation, less stem lucencies, higher ASES scores, and lower postoperative VAS pain scores. However, our study failed to demonstrate a difference in ROM, complication, or revision rates between HA and TSA.

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

BACKGROUND: 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 (1) metal-augmented baseplate prevents the medialization of the joint line and preserves glenoid bone stock similarly to bony increased-offset (BIO)-RSA and (2) bone graft viability and healing in BIO-RSA patients become compromised over time. MATERIALS AND METHODS: Eighty-one patients (83 shoulders) underwent glenoid lateralization with bone (BIO-RSA group, 44) or metal-augmented baseplate (metallic increased-offset [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 (ß angle) and retroversion were also measured. RESULTS: Delta scores of active anterior elevation were higher in the MIO-RSA group (P = .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, and 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 = .022), whereas the values of ß angle and postoperative retroversion were similar in the 2 groups. BIO-RSA group showed radiolucent lines <2 mm 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 rates of humerus condensation lines in MIO-RSA patients (P = .01) and higher rates of cortical thinning and tuberosity resorption in the BIO-RSA group (P = .027 and P = .004, respectively). CONCLUSION: 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 patients raise concern about the risk of baseplate loosening and requires further long-term studies.

Obesity is associated with an increased risk of undergoing shoulder arthroplasty in Australia.

BACKGROUND: The aim of this study was to examine the incidence of overweight and obesity in patients undergoing primary total shoulder arthroplasty (TSA) for osteoarthritis (OA) in Australia compared to the incidence of obesity in the general population. MATERIALS AND METHODS: A 2017/18 cohort consisting of 2997 patients from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) who underwent TSA were compared with matched controls from the Australian Bureau of Statistics (ABS) National Health Survey from the same time period. The 2 groups were analyzed according to body mass index (BMI) category, sex, and age. RESULTS: According to the 2017/18 National Health Survey, 35.6% of Australian adults were overweight and 31.3% were obese. Of the primary TSA cases performed, 34.9% were overweight and 50.1% were obese. The relative risk of requiring TSA for OA increased with increasing BMI category. Class III obese females, aged 55-64, were 8.6 times more likely to receive a TSA compared to their normal weight counterparts. Males in the same age and BMI category were 2.5 times more likely. Class III obese patients underwent TSA 4 years (female) and 6 years (male) younger than their normal weight counterparts. CONCLUSION: Obesity significantly increases the risk of requiring TSA. The association appears to be particularly strong for younger females.

Shoulder structure and function: The impact of osteoarthritis and rehabilitation strategies.

STUDY DESIGN: Invited review. BACKGROUND: Shoulder osteoarthritis can result in significant functional deficits. To improve diagnosis and treatment, we must better understand the impact of osteoarthritis on shoulder biomechanics and the known mechanical benefits of currently available treatments. PURPOSE: The purpose of this paper is to present up-to-date data on the effects of osteoarthritis and rehabilitation on the biomechanical parameters contributing to shoulder function. With this goal, we also reviewed the anatomy and the ranges of motion of the shoulder. METHODS: A search of electronic databases was conducted. All study designs were included to inform this qualitative, narrative literature review. RESULTS: This review describes the biomechanics of the shoulder, the impact of osteoarthritis on shoulder function, and the treatment of shoulder osteoarthritis with an emphasis on rehabilitation. CONCLUSIONS: The shoulder is important for the completion of activities of daily living, and osteoarthritis of the shoulder can significantly reduce shoulder motion and arm function. Although shoulder rehabilitation is an integral treatment modality to improve pain and function in shoulder osteoarthritis, few high-quality studies have investigated the effects and benefits of shoulder physical and occupational therapies. To advance the fields of therapy and rehabilitation, future studies investigating the effects of therapy intensity, therapy duration, and the relative benefits of therapy subtypes on shoulder biomechanics and function are necessary.

Does the osteoarthritic shoulder have altered rotator cuff vectors with increasing glenoid deformity? An in silico analysis.

BACKGROUND: A transverse force couple (TFC) functional imbalance has been demonstrated in osteoarthritic shoulders by recent 3-dimensional (3D) muscle volumetric studies. Altered rotator cuff vectors may be an additional factor contributing to a muscle imbalance and the propagation of glenoid deformity. METHODS: Computed tomography images of 33 Walch type A and 60 Walch type B shoulders were evaluated. The 3D volumes of the entire subscapularis, supraspinatus, and infraspinatus-teres minor (ISP-Tm) and scapula were manually segmented. The volume masks and scapular landmarks were imported into MATLAB to create a coordinate system, enabling calculation of muscle force vectors. The direction of each muscle force vector was described in the transverse and vertical plane, calculated with respect to the glenoid. Each muscle vector was then resolved into compression and shear force across the glenoid face. The relationship between muscle force vectors, glenoid retroversion or inclination, compression/shear forces on the glenoid, and Walch type was determined using linear regression. RESULTS: In the transverse plane with all rotator cuff muscles combined, increasing retroversion was significantly associated with increasing posterior drag (P < .001). Type B glenoids had significantly more posterior drag than type A (P < .001). In the vertical plane for each individual muscle group and in combination, superior drag increases as superior inclination increases (P < .001). Analysis of individual muscle groups showed that the anterior thrust of ISP-Tm and supraspinatus switched to a posterior drag at 8° and 10° of retroversion respectively. The compression force on the glenoid face by ISP-Tm and supraspinatus did not change with increasing retroversion for type A shoulders (P = .592 and P = .715, respectively), but they did for type B shoulders (P < .001 for both). The glenoid shear force ratio in the transverse plane for the ISP-Tm and supraspinatus moved from anterior to posterior shear with increasing glenoid retroversion, crossing zero at 8° and 10° of retroversion, whereas the subscapularis exerted a posterior shear force for every retroversion angle. CONCLUSION: Increased glenoid retroversion is associated with increased posterior shear and decreased compression forces on the glenoid face, explaining some of the pathognomonic bone morphometrics that characterize the osteoarthritic shoulder. Although the subscapularis always maintains a posterior thrust, the ISP-Tm and supraspinatus together showed an inflection at 8° and 10° of retroversion, changing from an anterior thrust to a posterior drag. This finding highlights the importance that in anatomic TSA the rotator cuff functional balance might be better restored by correcting glenoid retroversion to less than 8°.

Total shoulder replacement stems in osteoarthritis-short, long, or reverse? An analysis of the impact of crosslinked polyethylene.

BACKGROUND: The 2021 Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) report indicated that total shoulder replacement using both midhead (TMH) length humeral components and reverse arthroplasty (RTSA) had a lower revision rate than stemmed humeral components in anatomic total shoulder arthroplasty (aTSA)-for all prosthesis types and diagnoses. However, there are many factors that affect the outcome of total shoulder replacement, including stem length and polarity, polyethylene type, and glenoid fixation (cemented vs. cementless). The aim of this study was to assess the impact of these variables in the various primary total arthroplasty alternatives for osteoarthritis (OA) in the shoulder. METHODS: Data from a large national arthroplasty registry were analyzed for the period April 2004 to December 2020. The study population included all primary aTSA, RTSA, and TMH shoulder arthroplasty procedures undertaken for OA using either crosslinked polyethylene (XLPE) or noncrosslinked polyethylene (non-XLPE). Because of the previously documented and reported higher revision rate compared with other anatomic total shoulder replacement options, those using cementless metal-backed glenoid components were excluded. The rate of revision was determined by Kaplan-Meier estimates, with comparisons by Cox proportional hazard models. Reasons for revision were also assessed. RESULTS: For a primary diagnosis of OA, aTSA with a cemented XLPE glenoid component had the lowest revision rate, with a 12-year cumulative revision rate of 4.7%, compared with aTSA with cemented non-XLPE glenoid component at 8.7% and RTSA at 6.8%. The revision rate for TMH (with XLPE or non-XLPE) was lower than aTSA with cemented non-XLPE but was similar to the other implants at the same length of follow-up. The reason for revision of cemented aTSR was most commonly component loosening, not rotator cuff deficiency. CONCLUSION: Long-stem humeral components matched with XLPE in aTSA achieve a lower revision rate compared with shorter stems, long stems with conventional polyethylene, and RTSA when used to treat shoulder OA. In all these cohorts, loosening, not rotator cuff failure, was the most common diagnosis for revision.

Survey of Shoulder Osteoarthritis in Patients who Underwent Total Hip Arthroplasty for Hip Osteoarthritis.

To the best of our knowledge, no previous studies have reported a relationship between osteoarthritis (OA) of the lower limbs and OA of the shoulder joints. We evaluated the correlation between shoulder OA and hip OA. We collected contrast-enhanced computed tomography (CECT) images of the shoulder joints of 159 patients with hip OA who underwent primary total hip arthroplasty (THA). The images, taken 1 week after THA to monitor venous thromboembolism (VTE), were used to examine the prevalence of shoulder OA. They were compared with those of 103 controls who underwent CECT during the same period to monitor VTE. Shoulder OA was observed in 15% of the controls and 24% of the THA patients. Although the rate was somewhat higher in the THA group, the difference was not significant. However, in the THA group, significantly more patients with bilateral hip OA (33%) had shoulder OA than those with unilateral hip OA (17%). In summary, the prevalence of shoulder OA was significantly higher in patients with bilateral hip OA. In these patients, pain and instability in the hip joints require them to use arm support to stand up or walk, putting the weight-bearing shoulder at risk of developing OA.

11% complications rate after Latarjet procedure at up to 14 years follow-up.

PURPOSE: Evaluate complications in correlation with radiological findings after an open Latarjet procedure performed on 140 shoulders with recurrent anterior instability with follow-up from 8 to 174 months. METHODS: Retrospectively, 140 shoulders, diagnosed with recurrent anterior glenohumeral instability, which were surgically treated with the open Latarjet procedure in our hospital, between January 2004 and November 2017, had been analysed. Mean age of operated patients was 29.5 years. One hundred and twenty-three patients were male (88.5%) and 16 were female (11.5%). Average length of follow-up was 110 months. Radiographs and CT scans of 16 patients with complications had been evaluated and correlations between radiological findings and observed complications had been analysed. RESULTS: Complications occurred in 16 shoulders (11%). Rates of individual complications were: 1. persistent pain (9%), 2. limited ROM (7%), 3. recurrent instability (6%), 4. neurologic injury (2%), 5. persistent apprehension (2%), 6. reduced strength (2%), 7. hematoma (1%) and 8. intraoperative coracoid graft fracture (0.8%). Mean postoperative ASES score and ROWE score were statistically significantly lower in the group with complications, compared to the group without complications. Good or excellent results were reported by 87.9% patients. CONCLUSION: Open Latarjet procedure is an effective and safe method for the treatment of recurrent shoulder instability, resulting in good to excellent outcomes in 87.9% of our cases. However, it is related to a higher postoperative complication rate compared to some other treatment options. Overall, very good results with high level of patient satisfaction have been demonstrated.

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.