Fibroblast activation and inflammation in frozen shoulder.

INTRODUCTION: Frozen shoulder is a common, fibro-proliferative disease characterised by the insidious onset of pain and progressively restricted range of shoulder movement. Despite the prevalence of this disease, there is limited understanding of the molecular mechanisms underpinning the pathogenesis of this debilitating disease. Previous studies have identified increased myofibroblast differentiation and proliferation, immune cell influx and dysregulated cytokine production. We hypothesised that subpopulations within the fibroblast compartment may take on an activated phenotype, thus initiating the inflammatory processes observed in frozen shoulder. Therefore, we sought to evaluate the presence and possible pathogenic role of known stromal activation proteins in Frozen shoulder. METHODS: Shoulder capsule samples were collected from 10 patients with idiopathic frozen shoulder and 10 patients undergoing shoulder stabilisation surgery. Fibroblast activation marker expression (CD248, CD146, VCAM and PDPN, FAP) was quantified using immunohistochemistry. Control and diseased fibroblasts were cultured for in vitro studies from capsule biopsies from instability and frozen shoulder surgeries, respectively. The inflammatory profile and effects of IL-1ß upon diseased and control fibroblasts was assessed using ELISA, immunohistochemistry and qPCR. RESULTS: Immunohistochemistry demonstrated increased expression of fibroblast activation markers CD248, CD146, VCAM and PDPN in the frozen shoulder group compared with control (p < 0.05). Fibroblasts cultured from diseased capsule produced elevated levels of inflammatory protein (IL-6, IL-8 & CCL-20) in comparison to control fibroblasts. Exposing control fibroblasts to an inflammatory stimuli, (IL-1ß) significantly increased stromal activation marker transcript and protein expression (CD248, PDPN and VCAM). CONCLUSIONS: These results show that fibroblasts have an activated phenotype in frozen shoulder and this is associated with inflammatory cytokine dysregulation. Furthermore, it supports the hypothesis that activated fibroblasts may be involved in regulating the inflammatory and fibrotic processes involved in this disease.

Isolation and characterization of human mesenchymal stem cells derived from shoulder tissues involved in rotator cuff tears.

BACKGROUND: Recent studies report a relatively high failure rate for tendon-bone healing after rotator cuff repair. Several studies have investigated biologically augmented rotator cuff repair; however, none has shown the application of synovial mesenchymal stem cells for such repair. PURPOSE: To demonstrate whether cells derived from shoulder tissues have mesenchymal stem cell properties and to identify which tissue is the best source of the mesenchymal stem cells. STUDY DESIGN: Controlled laboratory study. METHODS: Forty-two patients with a diagnosed rotator cuff tear preoperatively were enrolled in this study. Human mesenchymal tissues were obtained during arthroscopic surgery for rotator cuff tears from 19 donors who met the inclusion criteria and had investigable amounts of tissue. Colony-forming units, yield obtained, expandability, differentiation potential, epitope profile, and gene expression were compared among the cells from 4 shoulder tissues: synovium of the glenohumeral joint, subacromial bursa, margin of the ruptured supraspinatus tendon, and residual tendon stump on the greater tuberosity (enthesis). RESULTS: The number of live passage 0 cells from whole tissue was significantly higher in cells derived from the subacromial bursa (P < .05). Subacromial bursa-derived cells retained their expandability even at passage 10. In adipogenesis experiments, the frequency of Oil Red O-positive colonies was significantly higher for synovium- and subacromial bursa-derived cells than for tendon- and enthesis-derived cells (P < .0001). In studies of osteogenesis, the rate of von Kossa- and alkaline phosphatase-positive colonies was highest in subacromial bursa-derived cells (P < .0001). The chondrogenic potential was highest in cells derived from the enthesis. For epitope profiling, 11 surface antigens were measured, and most had similar epitope profiles, irrespective of cell source. CONCLUSION: The findings indicate that the subacromial bursa is a good candidate for the source of mesenchymal stem cells in rotator cuff tears. CLINICAL RELEVANCE: Synovial cells from the subacromial bursa in patients with rotator cuff tears are a superior cell source in vitro, suggesting that mesenchymal stem cells from this tissue could be good candidates for biological augmentation of rotator cuff repair.

High origin of the anterior band of the inferior glenohumeral ligament: MR arthrography with anatomic and histologic correlation in cadavers.

INTRODUCTION: The anterior band of the inferior glenohumeral ligament has been described to arise from the anteroinferior labrum, but we have observed that in some persons its origin is from the anterior or anterosuperior labrum, creating diagnostic difficulties. MATERIALS AND METHODS: Ten fresh unembalmed cadaveric shoulders underwent magnetic resonance arthrography (MRA) using a posterior approach with a 1.5 T GE magnet, with the following sequences: T1-weighted fast spin-echo in axial, coronal and sagittal planes, and T1 fat-suppressed spin-echo in the axial plane (TR/TE 600/20, section thickness 2.5 mm, 0.5 mm interslice space, number of signals acquired, two, field of view 12 × 12 cm, and matrix 512 × 256 pixels). Following imaging, the shoulders were frozen and later sectioned using a band saw into 3-mm sections corresponding to the axial imaging plane. Histological analysis was also performed to determine the origin of the anterior band. RESULTS: Four of the ten shoulders had an origin of the anterior band above or at the 3 o'clock position: one at the 1 o'clock position, two at the 2 o'clock position, and one at the 3 o'clock position. In another shoulder, the anterior band of the inferior glenohumeral ligament originated from the middle glenohumeral ligament, and in five other shoulders, the anterior band originated from the anteroinferior labrum as has been described in the literature. CONCLUSIONS: This finding is of clinical significance as a high origin of the anterior band of the inferior glenohumeral ligament leads to MR arthrographic finding that can simulate those of labral tears or detachments.

An anatomic and histologic study of the coracohumeral ligament.

Although the anatomy and histology of the coracohumeral ligament (CHL) play an important role in the diagnosis and treatment of frozen shoulder, they remain unclear. Our objective was to study the anatomic features of the CHL and analyze its histology. Twenty-six fresh-frozen, normal cadaveric shoulders were used to examine the position and morphology of the CHL and their relationship with the superior glenohumeral ligament and to determine the CHL's histologic features in comparison with the joint capsule and coracoacromial ligament. The CHLs were all located in the rotator interval, with an irregular trapezoidal structure. The subacromial bursa was above the CHL, and the subcoracoid bursa was below the it. The CHLs in all shoulders originated from the lateral aspect of the base of the coracoid process. In 11 shoulders, it inserted into the supraspinatus tendon, whereas in 11 other shoulders, it inserted into the rotator interval. In 3 shoulders, the CHLs were split and inserted into both the supraspinatus and subscapularis tendons, respectively. Finally, the CHL in 1 shoulder only inserted into the subscapularis tendon. We also observed that the pectoralis minor tendons in 4 shoulders passed over the coracoid process top and inserted into the CHLs. In 11 shoulders, a complex of the CHL and the superior glenohumeral ligament was formed. Histologically, the CHL was found to be similar to the joint capsule without any ligament features. The position, morphology, and origin of the CHL did not change much, but its insertion varied greatly. In addition, the CHL had the histologic feature of a capsule, not a ligament.

Evaluation of clinical, radiographical and cytological findings compared to arthroscopic findings in shoulder joint lameness in the dog.

Forty-two dogs with lameness emanating from the shoulder joint were studied by clinical examination, radiographic examination, joint fluid analysis, and arthroscopic examination, following a set protocol. Dogs with mild clinical signs, absent or mild radiographic signs of osteoarthrosis, and without or with very mild changes in the synovial fluid, may still have moderate to severe degenerative pathological changes in the shoulder joint.

Revision shoulder arthroplasty with positive intraoperative cultures: the value of preoperative studies and intraoperative histology.

Currently, there are no reported results of patients without overt infection who had a positive intraoperative culture during revision shoulder arthroplasty. We therefore reviewed the intraoperative and preoperative investigations as well as the postoperative course of these patients who had positive intraoperative cultures. We reviewed the results of 75 shoulders without overt infection that underwent revision shoulder arthroplasty at our institution between January 1, 1974 and December 31, 2002 who had positive intraoperative cultures. Preoperatively, the results of 67 (93%) of 72 white-blood-cell counts were negative, 64 (91%) of 70 polymorphonuclear percentage distributions were negative, and 36 (86%) of 42 samples of erythrocyte sedimentation rate were negative. C-reactive protein concentration was measured in 16 patients, of which 12 (75%) had negative results. Results of intraoperative histologic evaluations were negative in 67 (92%) of 73 patients. The most common pathogen cultured was Propionibacterium acnes in 45 of 75, followed by Staphylococcus epidermidis in 10 of 75. Another operation was necessary in 10 (13%) of 75 shoulders to decrease pain or improve function. The mean time to re-revision was 2.5 years. The data from this study suggest that there are no good preoperative or intraoperative investigations to detect who will have a positive intraoperative culture at the time of revision shoulder arthroplasty.

Topography of muscle spindles and Golgi tendon organs in shoulder muscles of "Monodelphis domestica".

The topography of muscle spindles and Golgi tendon organs in the rotator cuff and surrounding shoulder muscles of a small laboratory marsupial (monodelphis domestica) were studied using light microscopy of serial sections. The shoulder joint of monodelphis has a large degree of freedom of movement allowing this animal to use the upper extremities for a wide range of activities like climbing and manipulating food. Thus, similar to the situation in man the shoulder joint is mainly secured by muscles. Silver stained serial paraffin sections were examined under the light microscope and the distribution of muscle spindles and Golgi tendon organs was reconstructed using three-dimensional image processing. In the two animals examined 113 and 131 muscle spindles respectively were found within the 4 rotator cuff muscles. In addition, 76 and 40 Golgi tendon organs respectively were seen at the musculo-tendinous junctions of these muscles preferentially close to the insertion at the humerus head. Also the surrounding shoulder muscles contain both muscle spindles and Golgi tendon organs in large numbers, but the ratio of Golgi tendon organs per muscle spindle appears to be lower. Number and localization of muscle spindles and Golgi tendon organs suggest, that these receptors are important for both reflex control of shoulder muscle tone as well as monitoring of static position and movement in the shoulder joint.

Multiquadrant digital analysis of shoulder capsular thickness.

PURPOSE: Nonablative thermal capsular shrinkage has been developed in an attempt to address the plastic capsule deformation thought to cause increased rates of recurrent instability following arthroscopic stabilization procedures. Although the temperature required to optimize collagen shrinkage is known, a safe depth of thermal penetration, in various locations about the shoulder capsule, has not been defined. The purpose of this study was to measure shoulder capsule thickness by quadrant and circumferentially from the glenoid to the humerus so that thermal energy in shoulder procedures can be more precisely applied to limit possible injury to pericapsular structures. TYPE OF STUDY: This is an anatomic study using a cadaveric shoulder specimens. MATERIALS AND METHODS: Soft tissue was dissected from 8 fresh cadaveric shoulders to isolate intact glenohumeral joint capsules. The humeral insertion was released and the capsule was cut into 6 longitudinal quadrants around the glenoid. The capsule specimens were then flash frozen and stored at -80 degrees C. Quadrant tissue was cut into longitudinal sections 14 to 16 microm wide and stained with hematoxylin and eosin. The specimens were then digitized under a dissecting microscope and measured using computer imaging software at approximately 4-mm intervals. Two-way analysis of variance (ANOVA) was performed on the measurements of the intact capsule specimens 2.5 cm off the glenoid. Humeral insertion data were recorded separately. RESULTS: A total of 248 separate measurements were made throughout the capsule in 8 specimens. Capsular thickness increased from an average of 2.42 mm anteriorly to 2.80 mm in the inferior capsular pouch and again thinned to 2.22 mm posteriorly. Global shoulder capsule thickness ranged from 1.32 to 4.47 mm. When analyzed by position, from glenoid to humerus, a general thinning was noted with a mean thickness of 3. 03 mm at the glenoid to 2.17 mm at the humeral insertion. Two-way ANOVA showed a significant thickness variation along the specimen (P <.05), a nearly significant thickness variation with regard to quadrant (P <.03), and no significant interaction (P >.07) when applied to specimen measurements approximately 2.5 cm off the glenoid. CONCLUSIONS: The thickness of the shoulder capsule ranges from 1.32 to 4.47 mm, with a significant thinning laterally from the glenoid to the humerus. Further, capsule thickness ranges from 2.76 to 3.18 mm in the regions in closest proximity to the axillary nerve. These data may help determine the proper amount of thermal penetration necessary when performing shrinkage procedures and provide safety guidelines to limit the depth of thermal penetration to avoid possible injury to pericapsular structures.

The effect of thermal heating on the length and histologic properties of the glenohumeral joint capsule.

The purpose of this study was to evaluate the effect of temperature on shrinkage and the histologic properties of glenohumeral joint capsular tissue. Six fresh-frozen cadaveric shoulders were used for this study. Seven joint capsule specimens were taken from different regions from each glenohumeral joint and assigned to one of seven treatment groups (37 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees C) using a randomized block design. Specimens were placed in a tissue bath heated to one of the designated temperatures for 10 minutes. Specimens treated with temperatures at or above 65 degrees C experienced significant shrinkage compared with those treated with a 37 degrees C bath. The posttreatment lengths in the 70 degrees, 75 degrees, and 80 degrees C groups were significantly less than the pretreatment lengths. Histologic analysis revealed significant thermal alteration characterized by hyalinization of collagen in the 65 degrees, 70 degrees, 75 degrees, and 80 degrees C groups. This study demonstrated that temperatures at or above 65 degrees C caused significant shrinkage of glenohumeral joint capsular tissue. These results are consistent with histologic findings, which revealed significant thermal changes of collagen in the 65 degrees, 70 degrees, 75 degrees, and 80 degrees C groups. To verify the validity of laser application for shrinkage of joint capsule, studies designed to compare these findings with the effects of laser energy must be performed.

Estudo morfológico e biomecânico dos tendöes do músculo supra-espinhoso e porçäo longa do píceps braquial / Morphplogical biomechanical study the tendons of the supraspinatus and biceps brachii

Tendöes do músculo supre-espinhoso e biceps braquial de 57 adultos submetidos a autópsia foram estudados para avaliar-se a freqüência de rotura tendinosa, comprimento do tendäo e resistência à traçäo. No grupo com idade entre 20 e 50 anos, nenuma rotura tendinosa foi observada, contrastando com a pecentagem de 66,7 por cento, observada na faixa etária entre 71 e 80 anos. O comprimento dos tendöes apresentou aumento com o avanço da idade e a resistência à traçäo nos grupos com idade entre 61 e 80 anos era 40 por cento menor do que nos grupos com idade entre 20 e 40 anos. A resistência à traçäo do tendäo do músculo bíceps braquial estava nos grupos etários mais avançados 28 por cento reduzida, em relaçäo aos mais jovens

Anatomy, histology, and vascularity of the glenoid labrum. An anatomical study.

We studied the gross, histological, and vascular anatomy of the glenoid labrum in twenty-three fresh-frozen shoulders from cadavera to demonstrate its cross-sectional anatomy, its microvascularity, and its attachments. The superior and anterosuperior portions of the labrum are loosely attached to the glenoid, and the macro-anatomy of those portions is similar to that of the meniscus of the knee. The superior portion of the labrum also consistently inserts directly into the biceps tendon, while its inferior portion is firmly attached to the glenoid rim and appears as a fibrous, immobile extension of the articular cartilage. The arteries supplying the periphery of the glenoid labrum come from the suprascapular, circumflex scapular, and posterior circumflex humeral arteries. In general, the superior and anterosuperior parts of the labrum have less vascularity than do the posterosuperior and inferior parts, and the vascularity is limited to the periphery of the labrum. Vessels supplying the labrum originate from either capsular or periosteal vessels and not from the underlying bone.

Fibrous structure of the joint capsule in the human shoulder.

The fibrous structure and arrangement of joint capsules of human shoulders [8 males (7 right, 6 left), 4 females (4 right, 3 left)] were observed under a low magnification microscope as well as a polarized microscope on film preparations (Häutchen-Präparat, Vogt 1935) with reference to stained sections (mainly with H, E and orcein). The joint capsule is composed of synovial and fibrous layers and is classified into three types according to tissue composition [areolar (loose connective tissue-Fawcett, 1986) type, fibrous (dense fibrous- Fawcett, 1986) type and adipose type- (Key 1932)]. In the joint capsule of the shoulder, the areolar type was found in the anterior region, and the fibrous type in the posterior, superior and inferior regions; the adipose type was not found. The author found that the fibrous layer of the fibrous type basically has a 3 layered structure; the composition and arrangement of fibers differ depending on the type of layer. These three layers were named in order from the synovial layer as "Internal fibrous layer (IFL)", "Intermediate fibrous layer (MFL)" and "External fibrous layer (EFL)". The external fibrous layer can normally be directly visualized by peeling off the muscles. The EFL consists of external fascia, tendons and their transitional regions, which compose the joint of the shoulder. IFL and MFL can only be observed under a low magnification microscope and are distinguishable on film preparations. The IFL, which is located immediately under the stratum synoviale, consists of fibrous bundles approximately 20 microns thick. The MFL, which is adjacent to the IFL, consists of 100-400 microns thick fibrous bundles. The IFL and the MFL have a differently fixed arrangement. The fibrous bundle of EFL is slightly thicker than that of IFL and the arrangement of the fibrous bundle is like that of supraspinatus m., infraspinatus m. and teres minor m. in the superior and posterior regions of the joint capsule. The local existence as well as the arrangement of the fibrous layer of these three different types is discussed from the standpoint of mechanical movement of the shoulder joint.

Effects of exercise on the histochemical changes of articular chondrocytes in adult dogs.

Effects of exercise regimens on the enzyme histochemical changes of articular chondrocytes of the humeral heads in adult shepherd-type dogs were studied. One group of 4 dogs was exercised by walking on a flat surface 5 days a week for 6 months. A 2nd group of 4 dogs was exercised under the same conditions, except that the dogs were forced to walk over platforms placed in their path. Three control dogs were exercised ad libitum in their housing area. In all dogs, the reactivity of lactic acid dehydrogenase was quite strong nicotinamide dinucleotide dehydrogenase was moderate, and glucose-6-phosphatase was week. Succinic acid dehydrogenase uridine diphosphate (UDP)-galactose-4-epimerase, and UDP-N-acetylglucosamine-4-epimerase were of weakly moderate staining reactivity. Consistent regional or laminar variability was not found among the chondrocytic populations of the exercised and control groups for the reactivity of the enzymes studied. However, regional and/or laminar variabilities in individuals of the experimental groups were identified. The weak reactivity of glucose-6-phosphatase as seemingly contradictory to the presence of intracellular lipids of adult articular chondrocytes. Lipid synthesis was suggested as a mechanism to store excessive quantities of hydrogen ions in an innocuous form, rather than in the potentially deleterious by-product of anaerobic glycolysis, lactic acid.