Glenohumeral joint injuries frequently result in shoulder instability. However, the biomechanical effect of cartilage loss on shoulder stability remains unknown. The aim of the current study was to investigate biomechanically the effect of two severity stages of cartilage loss in different dislocation directions on shoulder stability. Joint dislocation was provoked for 11 human cadaveric glenoids in seven different dislocation directions between 3 o'clock (anterior) to 9 o'clock (posterior) dislocation. Shoulder stability ratio (SSR) and concavity gradient were assessed in intact condition, and after 3 mm and 6 mm simulated cartilage loss. The influence of cartilage loss on SSR and concavity gradient was statistically evaluated. Between intact state and 6 mm cartilage loss, both SSR and concavity gradient decreased significantly in every dislocation direction (p≤0.038), except the concavity gradient in 4 o'clock dislocation direction (p=0.088). Thereby, anterior-inferior dislocation directions were associated with the highest loss of SSR and concavity gradient of up to 59.0% and 49.4%, respectively, being significantly higher for SSR compared to all other dislocation directions (p≤0.04). The correlations between concavity gradient and SSR for pooled dislocation directions were significant for all three conditions of cartilage loss (p<0.001). From a biomechanical perspective, articular cartilage of the glenoid contributes significantly to the concavity gradient, correlating strongly with the associated loss in glenohumeral joint stability. The highest effect of cartilage loss was observed in anterior-inferior dislocation directions, suggesting that surgical intervention should be considered for recurrent shoulder dislocations in the presence of cartilage loss

Introduction. The highest incidence of recurrent shoulder instability is in young patients, surgical repair can reduce recurrent instability and improve shoulder function. This has led to an increasing rate of stabilisation and use of MRI to identify associated injuries in first time dislocations. MRA has the benefit of distending the joint and is becoming increasingly used. The aim of this study is to establish the sensitivity and specificity of MRA in the investigation of patients with traumatic anterior shoulder dislocations. Methods. A retrospective analysis of patients undergoing both magnetic resonance arthrography and arthroscopy after a traumatic anterior shoulder dislocation between January 2011 and 2014. Images were interpreted by eight musculoskeletal radiologists and arthroscopic findings were obtained from surgical notes and used as a reference. The sensitivity, specificity and positive predictive value for the different injuries were calculated. Results. 60 patients were reviewed; 88% were male, mean age was 28 years (range 18 to 50) and 27% were primary dislocations. The overall sensitivity and specificity of MRA to all associated injuries was 0.9 (CI 0.83–0.95) and 0.94 (CI 0.9–0.96) retrospectively. The lowest sensitivity was seen in osseous Bankart 0.8 (CI 0.44–0.96) and SLAP lesions 0.5 (CI 0.14–0.86). Conclusion. MRA has a high sensitivity when used to identify associated injuries in shoulder dislocation although in 8 patients (13%) arthroscopy identified an additional injury. The overall agreement between MRA and arthroscopic findings was good but identification of GHL and rotator cuff injuries was poor. Level of Evidence. IV. Conflict of Interests. The authors confirm that they have no relevant financial disclosures or conflicts of interest. Ethical approval was not sought as this was a systematic review

Aims. Isolated greater tuberosity fractures make up 17–21% of proximal humeral fractures, 30% are associated with shoulder dislocation. Conservative management of minimally displaced fractures (<5 mm) is recommended. There are few guides to which and how many fractures displace over time. Methods. A retrospective analysis of isolated greater tuberosity fractures presenting to a shoulder fracture clinic over 1 year was performed. Patients were identified from shoulder fracture clinic lists and a bluespier database. Radiological fracture displacement was measured from the edge of the defect in the humeral head to the closest edge of the greater tuberosity. All measurements were performed by three oberservers on two occasions. Data was analysed to study the relationship between initial displacement and fracture stability and between concurrent dislocation and fracture stability. Inter-observer analysis was performed. Results. 64 (m:32; f:32; mean age 53) patients were identified. 37 were displaced 0–5 mm at presentation, 18 were displaced 5–10 mm, 9 were displaced >10 mm. Of those displaced less than 5 mm on presentation, 22% (n8) further displaced to greater than 5 mm and 5% (n2) to >10 mm at follow-up. Of those displaced 5–10 mm on presentation, 17% (n3) displaced to >10 mm. 42% (n27) of fractures were associated with dislocation; they had greater displacement at presentation. In the 0–5 mm displacement group that displaced >5 mm, 88% (n7) had concurrent dislocation. Inter-observer analysis of the x-ray measurement showed moderate agreement (0.684). Conclusion. Isolated greater tuberosity fractures displaced less than 5 mm at presentation and that are not associated with dislocation are stable. Concurrent dislocation is associated with both greater fracture displacement at presentation and ongoing fracture instability

Background. Hyperlaxity is associated with a high incidence of shoulder dislocations. Collagen V regulates the diameter of fibrils of the abundant collagen type I. Decorin and biglycan are members of the small leucine rich proteoglycans(SLRP's)family and play important roles in the regulation of collagen fibrillogenesis. The aim of this study was to identify if there was a link in hyperlaxity, capsule strength, collagen V and SLRP's expression. Methods. Data was collected for 10 patients undergoing open shoulder stabilization for recurrent instability. Beighton score was used to assess hyperlaxity. Localization of Collagen V and SLRP's was studied by immunohistochemical staining of paraffin embedded sections of shoulder capsule. Grading of the stain was done on a 0-4 scale(0=no staining and 4=strong staining>50% of the slide)by three observers. Shoulder capsules were mounted on a material testing system and vertical load was applied to reach yield. Results. The mean force required for yield in 15 shoulder capsules was 45N(17-78). Data was analysed for Group A(weak group) with yield<45N(8 specimens) and Group B(strong group)with yield>45N(7 specimens). The mean age was 26 years and all were male. The mean force for group A was 31N(17-41) and group B was 59N(45-78). The mean Beighton score for group A was 1.9(0-4) and Group B was 2. 2 specimens in Group A had Beighton score>4 as compared to 0 in Group B, indicating hyperlaxity. The mean grading of collagen V expression in synovial surface was 2.6,Blood vessels(BV)1.6 and extracellular matrix(ECM)1.9 in Group A and 4,3.1 and 2.6 respectively in group B. The mean grading of decorin expression for shoulder capsule was 2.7 in Group A and 3.3 in group B. The mean grading of Biglycan expression in synovial surface was 2,BV 2 and ECM 2.9 in Group A and 2,2.5 and 4 respectively in group B. Conclusions. We found that weaker capsule specimen(group A)had higher incidence of hyperlaxity. Decorin and biglycan expression in ECM and Collagen V expression in synovial surface, BV and ECM of shoulder capsule was higher in group B(strong group). This study shows a link between hyperlaxity, strength, Collagen V and SLRP's expression in shoulder capsule

Objectives

Intra-articular injections of local anaesthetics (LA), glucocorticoids (GC), or hyaluronic acid (HA) are used to treat osteoarthritis (OA). Contrast agents (CA) are needed to prove successful intra-articular injection or aspiration, or to visualize articular structures dynamically during fluoroscopy. Tranexamic acid (TA) is used to control haemostasis and prevent excessive intra-articular bleeding. Despite their common usage, little is known about the cytotoxicity of common drugs injected into joints. Thus, the aim of our study was to investigate the effects of LA, GC, HA, CA, and TA on the viability of primary human chondrocytes and tenocytes in vitro.