More tendon degeneration in patients with shoulder osteoarthritis.

PURPOSE: Tendon disorders are a major problem in the general population. It is known that rotator cuff tendinopathy contributes to osteoarthritis (OA) of the shoulder. The aim of the study was to analyse the presence of tendinopathy in patients with shoulder OA and an intact rotator cuff, using a multimodal approach. METHODS: Thirteen consecutive patients median age 67 (52-84) years, with OA of the shoulder, and 13 consecutive control patients, with a fracture of the proximal humerus, median age 70 (51-84) years, underwent an open biopsy procedure from the biceps and subscapularis tendon in conjunction with shoulder arthroplasty. In addition to a macroscopic evaluation, the samples underwent histologic, morphologic and ultrastructural analyses in light and transmission electron microscopy. RESULTS: Macroscopic degeneration was found in 15 of 26 specimen in the OA group but in seven of 25 in the control group (p = 0.048). The histologic analysis revealed a non-significant difference for the total degeneration score (TDS) between the study groups. The morphologic evaluation of the samples revealed that the OA group had significantly more samples with non-homogeneous extracellular matrix (ECM), (p = 0.048). Ultrastructurally, the OA group revealed a significantly larger fibril diameter in the biceps tendon (p < 0.0001) but not in the subscapularis tendon compared with the control group. CONCLUSION: A significantly worse macroscopic appearance and significantly more morphologically inhomogeneous ECM, indicating more tendon degeneration, were found in the OA group compared with the control group. This indicates that it could be beneficial to treat the tendinosis in an early stage to decrease symptoms from the OA. STUDY DESIGN: Level of evidence, III.

More histologic and ultrastructural degenerative signs in the subscapularis tendon and the joint capsule in male patients with shoulder impingement.

PURPOSE: The purpose of the present study was to analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with shoulder impingement syndrome (SAIS) and compare them with samples from male patients with post-traumatic recurrent shoulder instability. The hypothesis of the study was that patients with SAIS would have more histologic and ultrastructural degenerative changes in their subscapularis tendon and joint capsule than patients with post-traumatic recurrent shoulder instability. METHODS: Male patients scheduled for surgery, with either subacromial decompression or Bankart reconstruction, were included. Four biopsies from each patient were obtained from the capsule and four from the subscapularis tendon during arthroscopic surgery. The histologic characteristics and the presence of glycosaminoglycans were assessed using the light microscope, and the ultrastructure was assessed using a transmission electron microscope. RESULTS: Eight patients, median age 53 (45-74) years (p < 0.0001), were included in the impingement group, and 12 patients, median age 27 (22-48) years, were included in the instability group. The histologic assessment revealed significantly higher cellularity and total degeneration score in the capsule (p = 0.016 and p = 0.014 respectively) in patients with subacromial impingement compared with the instability patients. The corresponding finding was not made for the subscapularis tendon. The ultrastructural evaluation revealed that the instability patients had more fibrils with a large diameter (indicating less degeneration) in both the subscapularis tendon and the capsule compared with the impingement patients (p < 0.0001). CONCLUSION: Male patients with subacromial impingement have more histologic and ultrastructural degenerative changes in their shoulder compared with patients with post-traumatic recurrent shoulder instability. CLINICAL RELEVANCE: It appears that in patients with subacromial impingement, the whole shoulder joint is affected and not only the subacromial space. It is the opinion of the authors that intra-articular therapeutic injections could be tried more often in these patients. LEVEL OF EVIDENCE: III.

Dynamic high-resolution ultrasound of the shoulder: how we do it.

Ultrasonography (US) is an established and well-accepted modality that can be used to evaluate articular and peri-articular structures around the shoulder. US has been proven to be useful in a wide range of rotator cuff diseases (tendon tears, tendinosis, and bursitis) as well as non-rotator cuff abnormalities (instability problems, synovial joint diseases, and nerve entrapment syndromes). Diagnostic accuracy of shoulder US when evaluating rotator cuff tears can reach 91-100% for partial and full thickness tears detection, respectively, having been reported to be as accurate as magnetic resonance imaging in experienced hands. US is cheap, readily available, capable to provide high-resolution images, and does not use ionizing radiations. In addition, US is the only imaging modality that allows performing dynamic evaluation of musculoskeletal structures, that may help to further increase diagnostic performance. In this setting, a standardized imaging protocol is essential for an exhaustive and efficient examination, also helping reducing the intrinsic dependence from operators of US. Furthermore, knowledge of pitfalls that can be encountered when examining the shoulder may help to avoid erroneous images interpretation. In this article we use detailed anatomic schemes and high-resolution US images to describe the normal US anatomy of soft tissues, articular, and para-articular structures located in and around the shoulder. Short video clips emphasizing the crucial role of dynamic maneuvers and dynamic real-time US examination of these structures are included as supplementary material.

Hemiarthroplasty of the shoulder joint using a custom-designed high-density nano-hydroxyapatite/polyamide prosthesis with a polyvinyl alcohol hydrogel humeral head surface in rabbits.

In this study, a novel custom-designed high-density nano-hydroxyapatite/polyamide (n-HA/PA) prosthesis with a polyvinyl alcohol (PVA) hydrogel humeral head surface was employed to repair the shoulder joint head for hemiarthroplasty in rabbits. The prosthesis was fabricated using three-dimensional computed tomography and computer-aided design and computer-aided manufacturing systems for perfect fitting. Sixteen New Zealand white rabbits underwent humeral head excision, and received the composite prostheses for hemiarthroplasty. The implant sites were free from suppuration and necrosis at all periods. The X-ray results showed that there was a clear space between the prosthesis head and the glenoid surface, and the joint capsules and surfaces of the glenoid and PVA were well preserved without any damage during the whole inspection period. A high density of bone was observed around the firmware part of the prosthesis. Histological results revealed that significant osteogenesis was surrounding the firmware part, and the joint space was clear and the cartilage of the upper joint surface was basically intact. There was no visible absorption of the joint surfaces even after 3 months of continuous functional motions. The maximum tensile strength between the prosthesis and host bone reached 2.63 MPa at the 12th week postimplantation. In conclusion, the customized prosthesis by combination of PVA and high-density n-HA/PA has excellent biocompatibility and biological fixation, and offers a promising substitute for both the cartilage and the bone of the humeral head in a rabbit model as level V evidence.

A method for predicting collagen fiber realignment in non-planar tissue surfaces as applied to glenohumeral capsule during clinically relevant deformation.

Previously developed experimental methods to characterize micro-structural tissue changes under planar mechanical loading may not be applicable for clinically relevant cases. Such limitation stems from the fact that soft tissues, represented by two-dimensional surfaces, generally do not undergo planar deformations in vivo. To address the problem, a method was developed to directly predict changes in the collagen fiber distribution of nonplanar tissue surfaces following 3D deformation. Assuming that the collagen fiber distribution was known in the un-deformed configuration via experimental methods, changes in the fiber distribution were predicted using 3D deformation. As this method was solely based on kinematics and did not require solving the stress balance equations, the computational efforts were much reduced. In other words, with the assumption of affine deformation, the deformed collagen fiber distribution was calculated using only the deformation gradient tensor (obtained via an in-plane convective curvilinear coordinate system) and the associated un-deformed collagen fiber distribution. The new method was then applied to the glenohumeral capsule during simulated clinical exams. To quantify deformation, positional markers were attached to the capsule and their 3D coordinates were recorded in the reference position and three clinically relevant joint positions. Our results showed that at 60deg of external rotation, the glenoid side of the posterior axillary pouch had significant changes in fiber distribution in comparison to the other sub-regions. The larger degree of collagen fiber alignment on the glenoid side suggests that this region is more prone to injury. It also compares well with previous experimental and clinical studies indicating maximum principle strains to be greater on the glenoid compared to the humeral side. An advantage of the new method is that it can also be easily applied to map experimentally measured collagen fiber distribution (obtained via methods that require flattening of tissue) to their in vivo nonplanar configuration. Thus, the new method could be applied to many other nonplanar fibrous tissues such as the ocular shell, heart valves, and blood vessels.

Shoulder involvement in rheumatic diseases. Sonographic findings.

OBJECTIVE: To distinguish using shoulder sonography the different changes present in rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), and periarticular disorders (PD) of soft tissue of the shoulder. METHODS: Ninety shoulders of patients with RA, 32 with PMR, 122 with PD, and 108 controls were studied sonographically, using a 7.5 MHz linear probe. The following structures were evaluated: long head of biceps tendon, supraspinatus, infraspinatus and subscapularis tendons, subacromial and subscapularis bursae, rotator cuff (thickness), calcifications, and glenohumeral and acromioclavicular joints. Statistical analysis was by Student's t test and chi-squared test. RESULTS: Involvement of long head of biceps tendon (peritendinous fluid collection, changes of thickness, and/or echotexture) was significantly different between RA and PMR and between PD and PMR. Alterations in thickness and/or fibrillar pattern were evaluated in rotator cuff tendons: supraspinatus tendon was involved with significant differences between PD and both RA and PMR; the changes of subscapularis tendon were present, with significant differences between PD and both the other groups; the alterations of infraspinatus tendon were not statistically different between the 3 groups. Effusion within bursae was present, with significant differences only between RA and PD. The mean thickness of rotator cuff was significantly different between controls (6.2 mm) and both PD (5.3 mm) and RA (5.8 mm), and between PMR (6 mm) and PD. Evaluation of effusion within the glenohumeral joint (capsule-bone distance) showed significant differences between controls (2.4 mm) and both RA (4.2 mm) and PMR (4 mm), between RA and PD (2.6 mm), and between PMR and PD. Calcifications were present only in PD (21.3%) and RA (6.7%), with significant differences. Effusion within the acromioclavicular joint was present in RA (35.5%) and PD (20.5%), with significant differences. CONCLUSION: Shoulder sonography showed involvement of all structures in RA, the prevalence of effusion in PMR, and involvement mainly of tendons in PD.

[Histological and electron microscopic study of rotator cuff tear].

OBJECTIVE: To understand the changes of rotator cuff during tear and observe the pathologic and ultramicroscopic structure of rotator cuff. METHOD: Histological and ultra thin slides of samples of 36 cases of rotator cuff were made. RESULT: The degeneration of rotator cuff happened in synovium side, and then extended to the middle and deep sides of tendon. The deep side of cuff tendon could degenerate without synovium. The repair of tendon could be achieved with two types of healing. CONCLUSION: It would be difficult to achieve full repair when complete tear and deep side tear occurred to the rotator cuff.

Ultrastructural study of a perineurioma with ribosome-lamella complexes.

The participation of the perineurial cell in peripheral nerve tumors is the subject of much debate. The case of a 75-year-old female with a soft tissue tumor on her left shoulder is presented. The tumor had histological, ultrastructural, and immunohistochemical characteristics of a pure perineurial cell neoplasm. Ultrastructurally, distinctive ribosome-lamella complexes were found in the cytoplasm of the perineurial cells. This may be the first time that these structures have been described in perineurioma.

Histologic and scanning electron microscopic study of the glenoid labrum.

Three-dimensional fibrillar architecture of the glenoid labrum and its attachment to the glenoid rim were studied in 15 cadaveric shoulders to understand the pathophysiologic condition of various shoulder diseases. The true anatomic labrum was a narrow band located at the junction of the glenoid rim and fibrous capsule and varied considerably in size and shape. A triple-layered collagen structure of the labrum was observed by scanning electron microscopy. The thin superficial layer (articular surface) was a reticulated fibrillar network. The second layer was stratified. These two layers seem to act as a bumper against impact on the humeral head. The third, main layer of the labrum consisted of bundles of the fine fibrils densely arranged almost parallel to each other and oblique to the glenoid rim. This layer appears to act as a cushion to stabilize the shoulder joint.

Pseudoseptic arthritis: an unusual presentation of neuropathic arthropathy.

A 49 year old black man with scoliosis presented with bilateral shoulder swelling eventually shown to be due to neuropathic arthropathy related to underlying syringomyelia. The synovial fluid was highly inflammatory, but cultures from synovial fluid and synovial tissue were all sterile. Profuse fat droplets were noted and considered as a possible cause of the inflammation. This is an unusual presentation of neuropathic arthropathy in a patient who was also harbouring an adenocarcinoma that was undetected until later.

Collagen fiber arrangement of the human shoulder joint capsule--an anatomical study.

The polariscopic examination of isolated shoulder joint capsules shows that the entire capsule does not have a homogeneous collagen structure. Most of the capsule is characterized by regular collagen fibers which cross at an obtuse angle in the area of the musculus supraspinatus and at an acute angle in the area of the m. infraspinatus. The density of the collagen network increases from the medial to the lateral part. Deviating from this basic pattern of the joint capsule, there is a different collagen texture in the area between the m. supraspinatus and the m. subscapularis. This texture has dissociated, rarefied and irregular collagen fibers. This means that the area--in comparison with the remainder of the capsule--is characterized not only by missing reinforcing ligaments but also by a deviating pattern of the collagen fibers. This different collagen structure is already existent in the fetus.

Histopathological and ultrastructural studies of synovium in Milwaukee shoulder syndrome--a basic calcium phosphate crystal arthropathy.

Light and electron microscopic study of synovial specimens from four patients with the Milwaukee shoulder syndrome disclosed vascular congestion, villous and focal synovial lining cell hyperplasia, occasional giant cells, and fibrin deposition both within and on the surface of the synovium. Although these changes are non-specific, the finding of basic calcium phosphate crystal aggregates in all four cases and the near total absence of an inflammatory reaction are helpful in distinguishing this condition from other types of arthritis. The focal areas of synovial cell hyperplasia may relate to the powerful mitogenic effect of both synthetic and naturally occurring calcium-containing crystals in concentrations found in the synovial fluid of these patients.

Comparative study of the properties of the shoulder joint capsule with those of other joint capsules.

To compare the collagen structure of the shoulder joint with that of other joints, the collagen of shoulder, elbow, and hip joints was examined electron microscopically, electrophoretically, and by its response to mechanical stress. Collagen Types I, III, and V were common to joint capsules. Electron microscopy of shoulder and elbow joint capsules did not identify any structural difference. When subjected to a mechanical force, the shoulder joint showed a greater capacity to stretch than the elbow joint, and greater force was required to break the shoulder joint than the elbow joint.

Aging of the rotator cuff.

The many years of challenge in treating athletes disabled by tendinitis stimulated a study of the aging of tendons. Autopsy specimens, representing tendons from 20-, 50-, and 70-year-old subjects, were obtained. Each specimen, consisting of a wedge of the greater tuberosity with the attached supraspinatus tendon, was examined roentgenographically to study the morphologic features of the greater tuberosity and was decalcified and stained with Safranin O to evaluate the amount of fibro-cartilage, with van Gieson to identify Sharpey's fibers, and with hematoxylin and eosin to determine cellularity, fiber integrity, and vascularity of the tendon. The comparison related to chronological age documented a morphologic change of the greater tuberosity and progressive degeneration of all elements of the tendinous structures with progressive (1) osteitis of the greater tuberosity, cystic degeneration, and irregularity of the cortical margin; (2) degenerative sulcus between the greater tuberosity and the articular surface; (3) disruption of the integrity of the attachment of the tendon to the bone by Sharpey's fibers; (4) loss of cellularity, loss of staining quality, and fragmentation of the tendon; (5) diminution of the vascularity of the tendon; and (6) diminution of fibrocartilage.