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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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

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. 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 (β angle) and retroversion were also measured. 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 β 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). 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. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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°. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Shoulder osteoarthritis can be divided into different glenoid types (A, B, C, and D) and subtypes. The aim of this study was to investigate if there is an association between the prearthropathy scapular anatomy, shoulder osteoarthritis, and different glenoid types and subtypes. Using principal components analysis, a statistical shape model (SSM) of the scapula was constructed from a data set of 110 computed tomographic (CT) scans. These subjects formed the control group. Next, CT scan images of 117 patients with osteoarthritis were classified according to the modified Walch classification. A complete 3-dimensional (3D) scapular bone model was created for every patient, and using the SSM, a reconstruction of their prearthropathy scapular anatomy was performed. Automated 3D measurements were performed in both the patient and control group to obtain glenoid version and inclination, critical shoulder angle (CSA), posterior acromial slope (PAS), lateral acromion angle, scapular offset, and the rotational alignment of the coracoacromial complex. These parameters were compared between controls, patients with osteoarthritis, and glenoid types and subtypes. Mean version and inclination for the control group was 6° retroversion and 8° superior inclination (both SD 4°). The mean CSA, PAS, coracoid–posterior acromion angle, posterior acromion–scapular plane angle, and fulcrum axis ratio were 30° (SD 4°), 64° (SD 8°), 116° (SD 9°), 55° (SD 7°), and 46% (SD 4%), respectively. Patients with osteoarthritis had a significant lower CSA, posterior acromion–scapular plane angle, coracoid–posterior acromion angle, and fulcrum axis ratio (27°, 50°, 111°, and 44%, all P <.001). We found a significant difference between the control group and the respective glenoid types for the following parameters: mean CSA and coracoid–posterior acromion angle for A glenoids (27°, P =.001, and 111°, P =.007); mean version, CSA, PAS, coracoid–posterior acromion angle, posterior acromion–scapular plane angle, and fulcrum axis ratio for B glenoids (11°, 27°, 71°, 111°, 49°, and 43%, all P <.001); and mean version, CSA, and posterior acromion–scapular plane angle for D glenoids (2°, P =.002, 26°, P =.003, and 48°, P =.007). There seems to be an association between prearthropathy scapular anatomy and shoulder osteoarthritis. A small lateral extension and less posterior rotation of the acromion is associated with shoulder osteoarthritis and is present in almost all types and subtypes of glenoid morphology. Furthermore, B and D glenoids are associated with, respectively, a more and less pronounced prearthropathy glenoid retroversion. [ABSTRACT FROM AUTHOR]

Low-cost motion analysis systems (LCMASs) have emerged as easy and practical methods to measure the functional workspace (FWS). Thus, we ventured to apply an LCMAS, the Kinect2 gaming camera, to evaluate the FWS in patients with shoulder osteoarthritis (OA) and patients who underwent total shoulder arthroplasty (TSA) or reverse total shoulder arthroplasty (RTSA). A cross-sectional study of participants with OA (n = 53), TSA (n = 70), and RTSA (n = 34) was performed. The FWS as measured by an LCMAS, the American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment Form score, and the Patient-Reported Outcomes Measurement Information System (PROMIS) score were collected. For participants who underwent TSA or RTSA, the FWS was evaluated at 6, 12, and 24 months postoperatively. The correlation of the FWS with the ASES score and PROMIS score was determined. Significance was set at P <.05. Patients who underwent TSA or RTSA had a significantly higher FWS than patients with shoulder OA at almost all time points. Patients who underwent TSA had a significantly higher FWS than patients who underwent RTSA at 24 months after surgery. PROMIS and ASES scores showed strong correlations with the FWS in patients who underwent TSA (R = 0.75 [ P <.001] and R = 0.83 [ P <.001], respectively) and RTSA (R = 0.84 [ P <.001] and R = 0.73 [ P <.001], respectively). The FWS measured by an LCMAS is an easy and low-cost method to quantify the reachable space of the hand in patients and shows strong correlations with patient-reported outcome measures. This may be a useful tool to assess upper-extremity range of motion before and after shoulder arthroplasty. [ABSTRACT FROM AUTHOR]

The Walch type B glenoid has the hallmark features of retroversion, joint subluxation, and bony erosion. Although the type B glenoid has been well described, the morphology of the corresponding type B humerus is poorly understood. As such, the aim of this imaging-based anthropometric study was to investigate humeral torsion in Walch type B shoulders. Three-dimensional models of the full-length humerus were generated from computed tomography data for the Walch type B group (n = 59) and for a control group of normal nonarthritic shoulders (n = 59). An anatomic humeral head-neck plane was created and used to determine humeral torsion relative to the epicondylar axis. Measurements were repeated, and intraclass correlation coefficients were calculated. The type B humeri had significantly (P <.001) less retrotorsion (14° ± 9°) than the control group (36° ± 12°) relative to the epicondylar axis. Male and female individuals within the control group showed statistically significant differences in humeral torsion (P =.043), which were not found in the type B group. Inter-rater reliability showed excellent agreement for humeral torsion (intraclass correlation coefficient, 0.962). A subgroup analysis between Walch type B2 and B3 shoulders showed no significant differences in any of the humeral or glenoid parameters. The Walch type B humerus has significantly less retrotorsion than non-osteoarthritic shoulders. At present, it is unknown whether the altered humeral retrotorsion is a cause or effect of the type B glenoid. In addition, it is unknown whether surgeons should be reconstructing type B2 humeral component version to pathologic torsion or to nonpathologic population means to optimize arthroplasty survivorship. [ABSTRACT FROM AUTHOR]

Background Shoulder osteoarthritis is a gradual wearing of the articular cartilage concomitant with degenerative rotator cuff tears (RCTs). This pathologic disorder is related to inflammation, oxidative stress, and angiogenesis. Degenerative alterations may prompt production of cytokines and angiogenesis-related proteins, evoking rotator cuff diseases. This study tested the hypothesis that oxidative stress–responsive mediators can influence joint inflammation of patients with RCT. Methods Twelve healthy RCT patients not suffering shoulder osteoarthritis were categorized as the control group, and 24 patients were allocated to 2 RCT groups (RCTP1 and RCTP2), according to severity of RCT and glenohumeral arthritis. Cytokines, growth factors, and angiogenic biomarkers in synovial fluids, blood, platelet-rich plasma (PRP), and tendon tissues were analyzed with enzyme-linked immunosorbent assay, immunoblotting, and collagen zymography. Results Induction of interleukin 8, tumor necrosis factor α, and interleukin 1β was considerably elevated in synovial fluids of RCTP groups ( P  = .0398, P  = .0428, P  = .0828, respectively). The joint inflammation highly enhanced insulin-like growth factor 1 and transforming growth factor β1 (TGF-β1) in the synovial fluids and serum. Angiogenesis-related angiopoietin (Ang) 1 and 2, Tie-2, and hypoxia-inducible factor 1α were upregulated in reactive oxygen species–exposed RCTP synovium ( P  < .05). The production of matrix metalloproteinase 1 markedly increased in synovial fluids of the RCTP group ( P  = .043), whereas tissue collagen type I expression diminished with reduction of connective tissue growth factor expression ( P  = .032). Although the secretion of platelet-derived growth factor AB and vascular endothelial growth factor was marginal in the circulation ( P  = .714, P  = .335), platelet-derived growth factor AB, TGF-β1, Ang-1, and matrix metalloproteinase 1 were enriched in PRP of the RCTP group ( P  < .001, P  = .002, P  = .0389, respectively). Conclusions Synovial matrix degradation and oxidative stress–triggered angiogenesis may be involved in inducing RCT with joint inflammation. TGF-β1, Ang-1, and Ang-2 are the major components to repair RCT and to alleviate joint inflammation in PRP therapy. [ABSTRACT FROM AUTHOR]

Background In 2013 Moor et al introduced the concept of the critical shoulder angle (CSA) and suggested that an abnormal CSA was a leading factor in development of rotator cuff tear (RCT) and osteoarthritis (OA) of the shoulder. This study assessed whether the CSA was associated with RCT and OA and tested the inter- and intrarater reliability of the CSA when measuring RCT and OA. Materials and methods The study was performed as a retrospective case-control study. The cases comprised 2 groups: 97 patients with RCT and 87 patients with OA. The controls were matched 3:1, by age and sex, from a population of 795 patients with humeral fractures. The CSA was measured as described by Moor et al. Analysis of the relation with CSA for RCT and OA was done by logistic regression. Models were fitted separately for RCT and OA and used the controls matched to the respective cases. Inter- and intrarater reliability was determined by measuring the intraclass correlation coefficient and minimal detectable change. Results The mean CSA was 33.9° in the RCT group and 33.6° in the matched control group. The odds ratio for developing RCT for people with a CSA above 35° was 1.12 ( P  = .63). The mean CSA in the OA group was 31.1° and in the matched control group 33.3°. The odds ratio for developing OA for people with a CSA below 30° was 2.25 ( P  = .002). The CSA measurements showed strong intra- and inter-rater reliability, with intraclass correlation coefficient values above 0.92 and minimal detectable change values below 0.4°. Conclusions This study did not find any association between CSA and RCT but did show association between CSA and OA, with a 2.25 odds ratio of developing OA given the patient had a CSA below 30°. The results do not support the suggested praxis of shaving away the lateral border of the acromion to make the CSA smaller because it might increase the risk of developing OA without decreasing the risk of developing RCT. The CSA measurements showed excellent intra- and inter-rater reliability. [ABSTRACT FROM AUTHOR]

Background Chronic osteoarthritis can result in glenohumeral subluxation and loss of posterior glenoid bone. This can alter normal glenohumeral biomechanics and affect the stress placed on the glenoid implant after total shoulder arthroplasty. This study evaluated the clinical and radiographic results of an augmented all-polyethylene glenoid for the treatment of glenoid osteoarthritis in the presence of posterior glenoid bone loss and determined whether any failures or complications occurred with short-term follow-up. Methods During a 2-year period, 21 patients were treated with an augmented glenoid for an index diagnosis of osteoarthritis with a biconcave glenoid and average posterior glenoid bone loss of 4.7 mm. Clinical outcomes were recorded for the American Shoulder and Elbow Surgeons Shoulder Assessment, Simple Shoulder Test, and active motion. Radiographic analysis included glenoid version, humeral head subluxation, component seating, ingrowth, and loosening. Results Significant improvements were demonstrated for American Shoulder and Elbow Surgeons Shoulder Assessment (52.3), Simple Shoulder Test (8.1), forward flexion (50°), external rotation (32°), and pain. Radiographic improvements were found for glenoid version (12°), humeral scapular alignment (23%), and humeral glenoid alignment (8%). Central peg ingrowth was demonstrated in all patients, and complete component seating was achieved in 19 patients. No complications were encountered, and no clinical or radiographic failures were identified. Conclusion Augmented polyethylene glenoid components demonstrated improved clinical outcome, without implant failure or complications, during short-term follow-up. [ABSTRACT FROM AUTHOR]

Background: Total shoulder arthroplasty is technically demanding in regard to implantation of the glenoid component, especially in the setting of increased glenoid deformity and posterior glenoid wear. Augmented glenoid implants are an important and innovative option; however, there is little evidence accessible to surgeons to guide in the selection of the appropriate size augmented glenoid. Methods: Solid computer models of commercially available augmented glenoid components (+3, +5, +7) contained within the software allowed placement of the best fit glenoid component within the three-dimensional reconstruct of each patient’s scapula. Peg perforation, amount of bone reamed, and amount of medialization were recorded for each augment size. Results: There was strong correlation between the medialization of the joint line and the glenoid retroversion for each augmented component at neutral correction and correction to 6° of retroversion. At neutral, the range of retroversion that restored the anatomic joint line was ?3° to ?17° with use of the +3 augmented glenoid, ?5° to ?24° with the +5 augmented glenoid, and ?9° to ?31° with the +7 augmented glenoid. At 6° of retroversion, the range of retroversion that restored the anatomic joint line was ?4° to ?21° with use of the +3 augmented glenoid, ?7° to ?27° with the +5 augmented glenoid, and ?9° to ?34° with the +7 augmented glenoid. Conclusions: There was a strong correlation between glenoid retroversion and medialization for all augment sizes, supporting the recommendation for glenoid retroversion as the primary guide in selecting the amount of augmentation. [Copyright &y& Elsevier]

Background: The magnitude and anatomic consequences of pathologic acquired glenoid retroversion and posterior bone loss that can be surgically corrected with a standard versus an augmented glenoid component have not been studied extensively in a surgical patient population. Materials and methods: Twenty-nine patients with glenohumeral osteoarthritis, acquired posterior bone loss, and increased retroversion were studied by use of a three-dimensional computer surgical simulation. For each case, amount of medialization was measured as the linear distance from the lateral aspect of the glenoid vault model to the center of the articular implant surface. Simulation of implant placement at 0° or 6° was performed with use of a standard glenoid having a uniform thickness and an asymmetric thickness augmented component. Results: An increased amount of medialization was seen with the standard glenoid, 8.3 ± 4.1 mm, compared with 3.8 ± 3.3 mm with use of the augmented glenoid implant (P < .001). When glenoid retroversion was corrected to 0°, pathologic version was shown to have strong and significant relationship to the amount of medialization for both the standard (R 2 = 0.825) and augmented (R 2 = ?0.68) glenoid implant. There was an increased ability to correct greater amounts of pathologic version with less medialization by use of an augmented step glenoid compared with a standard anchor peg glenoid. Discussion: Correction of moderate to severe glenoid retroversion by asymmetric reaming cannot always be done with use of a standard component, and if it is done, it will result in greater medialization of the joint line. Use of an augmented component can allow complete correction of retroversion and minimize the effect of medialization. [Copyright &y& Elsevier]

Background and hypothesis: Posterior glenoid bone loss is found in a majority of patients with advanced osteoarthritis of the shoulder. In total shoulder arthroplasty, several methods currently exist for management of this bone loss, including the use of an augmented glenoid component. Different augmented glenoid designs would be expected to vary in their resistance to loosening during mechanical bench-top testing. Our hypothesis is that a stepped augmented glenoid component will have less mechanical liftoff than augmented components of varying designs without a step. Materials and methods: Four glenoid prototypes articulated with a humeral head were loaded with a 170-lb compressive load and with 4 mm of posterior-superior translation of the humeral head to 100,000 cycles. Anterior glenoid liftoff was measured. Results: The stepped glenoid component had significantly lower liftoff values (P < .05) compared with several other designs at many of the test intervals. Discussion: A stepped design for an augmented glenoid component has superior fixation and less anterior glenoid liftoff in the presence of eccentric loading and may have better long-term clinical results. [Copyright &y& Elsevier]

Background: The aim of this study was to evaluate the midterm results and complications of a total shoulder arthroplasty implanted with a metal-backed, bone-ingrowth glenoid component. Materials and methods: In total, 62 patients (65 shoulders) diagnosed with primary osteoarthritis were treated with total shoulder arthroplasty with a cementless glenoid component. The mean age was 66 years (range, 54-85 years). Fifty-three patients were evaluated after a mean of 64 months (range, 26-85 months). Functional results were documented by use of the age- and sex-adjusted Constant score. Radiolucent line (RLL) assessment of the glenoid component was performed by use of true anteroposterior and axillary views. Results: The Constant score improved significantly from 49% preoperatively to 89.8% postoperatively (P < .0001). Active range of motion improved significantly for flexion (from 118° to 146°), abduction (from 87° to 133°), and external rotation (from 21° to 44°) (P < .0001). In 3 cases (5.7%), RLLs of 1 mm or less were present, and 1 case (1.8%) had an RLL of 2 mm or less in 1 zone. Glenoid component loosening occurred in 5 cases (9.4%) because of breakage of the cage screw. Four of these patients presented preoperatively with a type B1 glenoid and one patient with type A2. Two of the patients who underwent revision also had a complete tear of the rotator cuff. The revision rate was 11.3% (6 patients) after a mean of 68 months. Conclusion: After midterm follow-up, clinical outcomes of patients operated on with a cementless, metal-backed glenoid implant improved significantly. However, an unacceptable rate of complications and revisions was found. Glenoid loosening predominantly occurred in patients with preoperative eccentric glenoid morphology and was also related to cranial migration of the proximal humerus during the follow-up period. [Copyright &y& Elsevier]

Hypothesis: Hemiarthroplasty for shoulder osteoarthritis with a glenoid dysplasia gives satisfactory results at medium-range follow-up. Materials and methods: From 1998 to 2006, 9 patients (10 shoulders) with glenoid dysplasia and osteoarthritis were treated with shoulder hemiarthroplasty. The mean age at surgery was 54 years (range, 44-73 years). At a minimum of 24 months after surgery, all patients were retrospectively reviewed with a clinical and radiographic evaluation. The average duration of follow-up was 71 months (range, 28-126 months). Results: One shoulder underwent revision surgery for anterior dislocation within 6 months after the initial procedure. The pain level improved significantly, with no or slight pain for 9 of the 10 shoulders. Postoperatively active external rotation and anterior elevation increased significantly, with a mean of 34.5° and 124°, respectively. The average American Shoulder and Elbow Surgeons score was 81.5 points at the last follow-up, and results were considered as excellent or satisfactory in 7 shoulders according to the modified Neer rating scale. Erosion of the glenoid was considered as slight on radiographs, and radiolucencies were seen around humeral stem in one case. Discussion: The opportunity of glenoid component implantation in case of anatomic shoulder replacement with dysplastic morphology has to be carefully evaluate because of bone stock insufficiency, glenoid orientation, and the age of patients. Conclusions: Despite a limited number of patients in this study, hemiarthroplasty gave satisfactory clinical results in most cases. It seems to be a reliable option to treat osteoarthritis in case of dysplastic morphology of shoulder. [ABSTRACT FROM AUTHOR]

Background Current techniques for resurfacing of the glenoid in the treatment of arthritis are unpredictable. Computed tomography (CT) studies have demonstrated that the medial tibial plateau has close similarity to the glenoid. The purpose of this study was to assess contact pressures of transplanted massive tibial osteochondral allografts to resurface the glenoid without and with CT matching. Methods Ten unmatched cadaveric tibiae were used to resurface 10 cadaveric glenoids with osteochondral allografts. Five cadaveric tibiae and glenoids were CT matched and studied. An internal control group of 4 matched pairs of glenoids, with the contralateral glenoid transplanted to the opposite glenoid, was also included as a best-case scenario to measure the effects of the surgical technique. All glenoids were tested before and after grafting at different abduction and rotation angles, with recording of peak contact pressures. Results Peak contact pressures were not different from the intact state in the autografted group but were increased in both allografted groups. CT-matched tibial grafts had lower peak pressures than unmatched grafts. Peak pressures were on average 24.8% (range [18.3%, 29.6%]) greater than in the native glenoids for unmatched allografts, 21.8% ([17.0%, 25.5%]) greater for the matched allografts, and 4.9% ([3.8%, 5.5%]) greater for matched autografts. Conclusion Osteochondral grafting from the medial tibial plateau to the glenoid is feasible but results in increased peak contact pressures. The technique is reproducible as defined by the autografted group. Contact pressures between native and allografted glenoids were significantly different. The clinical significance remains unknown. Peak pressures experienced by the glenoid seem highly sensitive to deviations from the native glenoid shape. [ABSTRACT FROM AUTHOR]

Background: Patients with osteoarthritis undergoing shoulder arthroplasty may suffer from osteoporosis. The purpose of this study was to determine whether computed tomography (CT)-derived Hounsfield unit (HU) measurements correlate with bone mineral density (BMD) and whether these data could predict implant size and fixation choice. Materials and methods: The study analyzed preoperative dual energy x-ray absorptiometry and shoulder CT scans for 230 patients who underwent total shoulder arthroplasty. Hip BMD and T scores and HU attenuation in the humerus were correlated. HU cutoff values were developed to aid in differentiating patients whose BMD values were within normal reference ranges from patients with osteopenia or osteoporosis. Risk factors associated with low BMD were correlated, and the effect of BMD on humeral stem size, and fixation method was investigated. Results: Significant correlations between HU and hip BMD and T score were identified (P < .001). HU value ranges were identified that may alert the surgeon of metabolic bone disease. Significant correlation (P < 0.05) was found between low BMD and certain osteoporosis risk factors. Age at time of surgery was a predictor of cemented stem fixation (P = .024). Patients with a lower BMD were statistically more likely to receive a larger-diameter humeral stem (P = .016). Conclusions: Orthopedic surgeons may be able to use data obtained from shoulder CT scans to predict the need for larger stem size or cement fixation during shoulder arthroplasty. In combination with the risk factor profile, these data may be useful in predicting the need for an osteoporosis workup and treatment. [ABSTRACT FROM AUTHOR]