Biochemical markers in synovial fluid identify early osteoarthritis of the glenohumeral joint

The value of the glenohumeral joint cross-sectional area as a morphological parameter of glenohumeral osteoarthritis

Glenohumeral joint (GHJ) space narrowing has been demonstrated to be an important morphologic parameter of glenohumeral osteoarthritis (GHO). However, the morphology of GHJ space is irregular because of degeneration of subchondral bone and articular cartilage. Thus, we devised GHJ cartilage cross-sectional area (GHJCCSA) as a new diagnostic morphological parameter to assess the irregular morphologic change of GHJ. GHJ samples were acquired from 33 patients with GHO and from 33 normal controls without evidence of GHO based on shoulder magnetic resonance imaging. T2-weighted coronal MRIs were collected at the GHJ level for all individuals. GHJCCSA and GHJ cartilage thickness (GHJCT) at the GHJ were measured on MRIs using a graphic measuring system. The GHJCCSA was measured as the whole cartilage cross-sectional area of the GHJ. The average GHJCCSA was 115.28 ± 17.36 mm2 in normal individuals and 61.77 ± 13.74 mm2 in the GHO group. The mean GHJCT was 2.06 ± 0.35 mm in normal individuals and 1.50 ± 0.28 mm in the GHO group. GHO patients had significantly lower GHJCCSA (P < .001) and GHJCT (P < .001) than normal individuals. Receiver operator characteristics curve analysis revealed that the optimal cutoff score of the GHJCCSA was 82.21 mm2, with a sensitivity of 97.0%, a specificity of 97.0%, and an area under the curve of 0.99 (95% CI: 0.97-1.00). Although GHJCCSA and GHJCT were both significantly associated with GHO, the GHJCCSA was a more sensitive measurement parameter.

Synovial Fluid Fatty Acid Profiles Are Differently Altered by Inflammatory Joint Pathologies in the Shoulder and Knee Joints

Anomalies of fatty acid (FA) metabolism characterize osteoarthritis (OA) and rheumatoid arthritis (RA) in the knee joint. No previous study has investigated the synovial fluid (SF) FA manifestations in these aging-related inflammatory diseases in the shoulder. The present experiment compared the FA alterations between the shoulder and knee joints in patients with end-stage OA or end-stage RA. SF samples were collected during glenohumeral or knee joint surgery from trauma controls and from OA and RA patients (n = 42). The FA composition of SF total lipids was analyzed by gas chromatography with flame ionization and mass spectrometric detection and compared across cohorts. The FA signatures of trauma controls were mostly uniform in both anatomical locations. RA shoulders were characterized by elevated percentages of 20:4n-6 and 22:6n-3 and with reduced proportions of 18:1n-9. The FA profiles of OA and RA knees were relatively uniform and displayed lower proportions of 18:2n-6, 22:6n-3 and total n-6 polyunsaturated FAs (PUFAs). The results indicate location- and disease-dependent differences in the SF FA composition. These alterations in FA profiles and their potential implications for the production of PUFA-derived lipid mediators may affect joint lubrication, synovial inflammation and pannus formation as well as cartilage and bone degradation and contribute to the pathogeneses of inflammatory joint diseases.

Use of magnetic capture to identify elevated levels of CCL2 following intra-articular injection of monoiodoacetate in rats

PURPOSE

Synovial fluid biomarkers help evaluate osteoarthritis (OA) development. Magnetic capture, our new magnetic nanoparticle-based technology, has proven to be effective for determining extracellular matrix fragment levels in two rat OA models. Here, the feasibility of magnetic capture for detecting monocyte chemoattractant protein-1 (MCP-1 or CCL2) is demonstrated after intra-articular injection of monoiodoacetate (MIA) in the rat knee.

METHODS

Forty-eight male Lewis rats received a right hind limb, intra-articular injection of MIA (1 mg in 25 µl of saline) or 25 µl of saline. Magnetic capture and lavage were performed at 7 days after injection (n = 6 per treatment per procedure), with magnetic capture additionally performed at 14 and 28 days post-injection (n = 6 per treatment per time point). CCL2 was also assessed in serum.

RESULTS

Serum CCL2 levels revealed no difference between MIA and saline animals (p = 0.0851). In contrast, magnetic capture and lavage detected a significant increase of CCL2 in the MIA-injected knee, with the MIA-injected knee having elevated CCL2 compared to contralateral and saline-injected knees (p = 0.00016 (contralateral) and p = 0.00016 (saline) for magnetic capture; p = 0.00023 (contralateral) and p = 0.00049 (saline) for lavage).

CONCLUSIONS

Magnetic capture of CCL2 was successfully developed and applied to determine levels of CCL2 in a rat knee. Magnetic capture detected a statistically significant increase of CCL2 in MIA-injected knees compared to controls, and CCL2 levels stayed relatively stable from week 1 through week 4 post-MIA injection.

Magnetic Capture of a Molecular Biomarker from Synovial Fluid in a Rat Model of Knee Osteoarthritis

Biomarker development for osteoarthritis (OA) often begins in rodent models, but can be limited by an inability to aspirate synovial fluid from a rodent stifle (similar to the human knee). To address this limitation, we have developed a magnetic nanoparticle-based technology to collect biomarkers from a rodent stifle, termed magnetic capture. Using a common OA biomarker--the c-terminus telopeptide of type II collagen (CTXII)--magnetic capture was optimized in vitro using bovine synovial fluid and then tested in a rat model of knee OA. Anti-CTXII antibodies were conjugated to the surface of superparamagnetic iron oxide-containing polymeric particles. Using these anti-CTXII particles, magnetic capture was able to estimate the level of CTXII in 25 μL aliquots of bovine synovial fluid; and under controlled conditions, this estimate was unaffected by synovial fluid viscosity. Following in vitro testing, anti-CTXII particles were tested in a rat monoiodoacetate model of knee OA. CTXII could be magnetically captured from a rodent stifle without the need to aspirate fluid and showed tenfold changes in CTXII levels from OA-affected joints relative to contralateral control joints. Combined, these data demonstrate the ability and sensitivity of magnetic capture for post-mortem analysis of OA biomarkers in the rat.

Identification of shoulder osteoarthritis biomarkers: comparison between shoulders with and without osteoarthritis

BACKGROUND

The biologic factors associated with shoulder osteoarthritis (OA) have not been elucidated. The purpose of this study was to investigate osteoarthritic biomarkers of the shoulder. To our knowledge, this is the first study to analyze shoulder cartilage for OA-associated genes and to examine human shoulder cartilage for a possible biomarker, connexin 43 (Cx43).

MATERIALS AND METHODS

Cartilage from 16 osteoarthritic and 10 nonosteoarthritic humeral heads was assessed for expression of the following genes by real-time polymerase chain reaction: types I, II, and X collagen; matrix metalloproteinases (MMPs); tissue inhibitors of MMP (TIMPs); interleukins; versican; cyclooxygenase 2 (Cox-2); inducible nitric oxide synthase (iNOS); tumor necrosis factor α (TNF-α); aggrecanase 2 (ADAMTS5); and Cx43.

RESULTS

In osteoarthritic shoulders, Cx43, Cox-2, versican, collagen type I, ADAMTS5, MMP-3, and TNF-α expressions were significantly increased compared with controls. TIMP-3 and iNOS trended toward significance, with robust expression in osteoarthritic shoulders and low expression in nonosteoarthritic shoulders. In osteoarthritic shoulders, gene expression of Cx43, ADAMTS5, collagen type I, Cox-2, versican, and TIMP-3 showed predominance (85-, 33-, 13-, 12-, 11.5-, and 3-fold increases, respectively) relative to nonosteoarthritic controls. Spearman correlation analysis showed significant correlations between Cx43 and collagen (types I, II, and X), MMP-9, TIMP-2 and TIMP-3, versican, Cox-2, iNOS, and ADAMTS5.

CONCLUSIONS

Certain genes are markedly upregulated in osteoarthritic shoulders compared with nonosteoarthritic shoulders, with Cx43, Cox-2, versican, collagen type I, ADAMTS5, MMP-3, and TNF-α expression being significantly increased. These genes might be useful biomarkers for examining shoulder OA.

CLINICAL RELEVANCE

Identification of osteoarthritic biomarkers can help us better understand shoulder OA and build the foundation for future research on disease progression and treatments.

Aggrecan and cartilage oligomeric matrix protein in serum and synovial fluid of patients with knee osteoarthritis

Aggrecan and cartilage oligomeric matrix protein (COMP) which are important degradation products of articular cartilage may be promising diagnostic markers in serum and/or synovial fluid for diagnosis of knee osteoarthritis (OA). Our objective was to measure serum and synovial fluid levels of aggrecan and COMP in patients with OA of the knee joint to find out if they could be of diagnostic value in OA and if their levels correlate with the clinical and radiological manifestations of the disease. Sixty-six patients suffering from primary knee OA with effusion (26 males and 40 females) were studied. Twenty individuals (six males and 14 females) with recent traumatic knee effusion matched for age and sex were chosen to serve as a control group. All subjects had thorough clinical and radiological (X-ray and MRI) evaluation. Aggrecan and COMP in serum and synovial fluid were measured by ELISA. Serum and synovial fluid aggrecan and COMP levels were significantly higher than the control. Serum and synovial fluid aggrecan and COMP levels were positively correlated with age, body mass index, disease duration, plain X-ray and MRI scores. In OA, serum and synovial fluid aggrecan and COMP levels are elevated and represent useful markers in the diagnosis. Moreover, these elevated levels positively correlated with radiological joint damage but not with clinical disease parameters. These markers have the potential to be used for monitoring articular cartilage destruction and response to different therapeutic modalities.

Shoulder pain in the elderly

Shoulder disorders are a common and sometimes underestimated cause of pain and disability in elderly people. Prevalence of shoulder disorders in the elderly community is 21% and this represents important implications in the provision of community health services. Shoulder disorders are more common in women (25%) than in men (17%). Although many of these patients do not seek medical advice, shoulder pain is a frequent cause of disability, poor subjective perception of health and depression. Soft tissue lesions are the most common cause of shoulder pain in the elderly, including rotator cuff tendinitis or rupture, subacromial impingement, frozen shoulder and acromioclavicular joint osteoarthritis. These conditions are amenable to treatment that in turn will improve patient quality of life. Minimally invasive techniques, especially shoulder arthroscopy, have demonstrated to be extremely useful for this purpose. Glenohumeral osteoarthritis, rheumatoid disease and Milwaukee shoulder are also frequent origins of shoulder ache. In these entities associated with joint destruction, shoulder replacement achieves excellent clinical results and survival rates comparable with knee or hip arthroplasty. Another common cause of shoulder problems in the elderly is fractures of the proximal humerus. These fractures should be regarded as typical osteoporotic fractures, and their incidence is increasing dramatically. They constitute the third most frequent osteoporotic fracture after vertebral and distal radius fractures and usually occur in active people. Half of these fractures are displaced and require surgical treatment. Since proximal humeral fractures usually occur at a younger age than hip fractures, they represent an important warning, forecasting more severe osteoporotic fractures.

Adhesive capsulitis: human fibroblast response to shoulder joint aspirate from patients with stage II disease

Abnormal fibroblast proliferation has been implicated in the pathogenesis of adhesive capsulitis. The aim of the study was to examine the effect of fluid aspirated from the glenohumeral joint of patients with adhesive capsulitis on human fibroblast cells. Shoulder aspirate from 15 patients with stage II adhesive capsulitis was obtained and diluted to concentrations of 10%, 25%, and 50%. Fifteen patients undergoing shoulder arthroscopy for instability comprised the normal control group. Human fibroblast cells were cultured from human volunteers. Cellular proliferation was determined by use of the Promega CellTiter 96 nonradioactive cell proliferation assay. Fibroblast proliferation was significantly increased in patients with adhesive capsulitis. The rate of increased fibroblast proliferation showed a dose-dependent relationship to aspirate concentration. There was a moderate increase in fibroblast apoptosis at higher aspirate concentrations (25% and 50%) as detected by the ability of apoptotic cells to bind annexin V and exclude propidium iodide. These findings demonstrate that fluid from shoulders with adhesive capsulitis contains growth factors that influence fibroblast activity.

The development of posttraumatic arthritis after articular fracture

Posttraumatic arthritis (PTA) is one of the most frequent causes of disability after trauma involving weight-bearing joints and is estimated to be responsible for approximately 10% of the 21 million Americans who have osteoarthritis. Despite a number of similarities in the pathology and end-stage disease of PTA with primary osteoarthritis, the mechanisms involved in the onset and progression of joint degeneration after articular fracture are poorly understood. The largest area of study regarding articular fractures and the development of arthritic changes has focused on the role of adequate surgical reduction of the articular surfaces. However, it is now apparent that a number of complex and interacting biomechanical, biochemical, and, possibly, genetic factors contribute to the development of osteoarthritic changes in the joint after joint trauma, ranging from the cell and molecular level to the joint and systemic level. In this paper, we discuss the potential roles of the initial impact and fracture as well as the subsequent alterations in joint loading, biomechanical and metabolic properties of the cartilage, local and systemic inflammatory cytokines, and viability of chondrocytes in the progression of PTA. An improved understanding of the mechanisms involved in the development of PTA will hopefully lead to the improvement of surgical and nonsurgical therapies for this disease.

The influence of mechanical compression on the induction of osteoarthritis-related biomarkers in articular cartilage explants

OBJECTIVE

Macromolecules of the articular cartilage extracellular matrix released into synovial fluid, blood, or urine can serve as potentially useful biomarkers of the severity of osteoarthritis (OA). Biomechanical factors play an important role in OA pathogenesis, yet their influence on biomarker production is not well understood. The goal of this study was to examine the hypothesis that dynamic mechanical stress influences the release of these biomarkers from articular cartilage.

METHODS

Explants of porcine cartilage were subjected to dynamic compression at 0.5 Hz for 24h at stresses ranging from 0.006 to 0.1 MPa. The concentrations of cartilage oligomeric matrix protein (COMP), keratan sulfate (KS measured as the 5 D 4 epitope), total sulfated glycosaminoglycan (S-GAG), and the KS (keratanase-digestible) and chondroitin sulfate (CS) (chondroitinase-digestible) fractions of S-GAG were measured. Radiolabel incorporation was used to determine the rates of proteoglycan and protein synthesis.

RESULTS

The magnitudes of mechanical stress applied in this study induced nominal tissue strains of 4-23%, consistent with a range of physiological to hyperphysiologic strains measured in situ. COMP release increased in proportion to the magnitude of dynamic mechanical stress, while KS, CS and total S-GAG release increased in a bimodal pattern with increasing stress. Protein and proteoglycan synthesis were significantly decreased at the highest level of stress.

CONCLUSION

Mechanical stress differentially regulates the turnover of distinct pools of cartilage macromolecules. These findings indicate that mechanical factors, independent of exogenous cytokines or other stimulatory factors, can influence the production and release of OA-related biomarkers from articular cartilage.

An immunohistochemical study of the rabbit suprapatella, a sesamoid fibrocartilage in the quadriceps tendon containing aggrecan

The rabbit suprapatella is a sesamoid fibrocartilage in the deep surface of the tendon of vastus intermedius and an integral part of the knee joint. We report the presence of a variety of proteoglycans (aggrecan and versican), glycosaminoglycans (chondroitin 4 and 6 sulfate, dermatan sulfate, keratan sulfate) and glycoproteins (tenascin) in its extracellular matrix and the intermediate filament vimentin in the fibrocartilage cells. The most significant finding is the presence of aggrecan in the extracellular matrix, along with its associated link protein and several of its integral glycosaminoglycans. Aggrecan probably enables the suprapatella to withstand compression. Although it can be assumed that aggrecan metabolites detected in synovial fluid from some human joints are predominantly associated with articular hyaline cartilage, the presence of aggrecan in the rabbit suprapatella means that this cannot be assumed for all animal knee joints. We conclude that it is important for orthopedic researchers who use animal models for arthritis research to check for the presence of a suprapatella when joint fluid analyses are interpreted.

Biochemical markers in the synovial fluid of glenohumeral joints from patients with rotator cuff tear

It is known that rotator cuff tears are sometimes accompanied by joint destruction. Our purpose was to elucidate the pathology with this condition. Thirty-two synovial fluid (SF) samples aspirated from the glenohumeral joints of patients with rotator cuff tears, including 7 with partial-thickness and 25 with full-thickness tears of the rotator cuff (10 massive and 15 isolated supraspinatus tendon (SSp) tears), were examined. Collagenase (MMP-1), stromelysin 1 (MMP-3), tissue inhibitor of metalloproteinases-1 (TIMP-1) and carboxy-terminal type II procollagen peptide (pCOL Il-C) were measured in the SF using the respective sandwich enzyme immunoassays. Glycosaminoglycan (GAG) was also quantified with a cationic dye binding method using 1,9-dimethylmethylene blue. Levels of any molecules except pCOL II-C in the SF appeared to be higher in full-thickness tears than those in partial-thickness tears. Moreover, levels of MMP-1, MMP-3 and GAG in the SF were significantly higher in massive tears of the rotator cuff in comparison with those in isolated SSp tears. Such significance was not observed in the levels of TIMP-1 or pCOL II C in the SF. We examined the relation of those levels with operative findings or clinical parameters from full-thickness tears, and observed significant correlations of the tear size with the levels of MMP-1, MMP-3 and GAG in the SF. Although these marker molecules in SF do not always originate from cartilage, our results may indicate the potential for accelerated cartilage-degrading activity in the glenohumeral joint in massive tears of the rotator cuff.

Cross-sectional comparison of synovial fluid biochemical markers in equine osteoarthritis and the correlation of these markers with articular cartilage damage

OBJECTIVE

To investigate the relationship between biochemical markers in the synovial fluid of osteoarthritic and contralateral equine joints and gross articular cartilage pathology.

DESIGN

Twenty-two horses underwent bilateral arthroscopy of their carpal or metacarpophalangeal joints following recent onset lameness. The degree of cartilage damage in each joint was scored and synovial fluid, from both the clinically affected and the contralateral joint, was collected. Bone specific alkaline phosphatase (BAP), 5D4 epitope of keratan sulphate (KS), total glycosaminoglycans (GAG) and hyaluronan (HA) were measured.

RESULTS

The mean age of the horses was 4.1 years and the maximum duration of lameness was three months. Joints examined were midcarpal, antebrachiocarpal and metacarpophalangeal. The median concentration (semi-interquartile range) of BAP was significantly higher in the clinically active joint than in the contralateral joint, 21.75 (6.22) vs. 12.35 (4.07) units, while the other biomarkers measured were significantly lower in the clinically active joint than in the contralateral joint, i.e. KS 8.79 (1.96) microg/ml vs. 16.39 (5.65) microg/ml, KS:GAG ratio 0.19 (0.04) vs. 0.31 (0.10) and HA 741.6 (222) microg/ml vs. 1061.75 (325) microg/ml. BAP was positively (R=0.57), and KS (R=-0.57) and KS:GAG ratio (R=-0.49) were negatively correlated to the degree of cartilage damage within the joint.

CONCLUSION

The correlation between articular cartilage damage and synovial fluid BAP and KS imparts validity to their potential use as non-invasive diagnostic aids in equine osteoarthritis (OA). The positive correlation between BAP and cartilage damage suggests that there is a link between bone turnover and cartilage damage in OA.

Epidemiologic study of glenohumeral osteoarthritis with plain radiography

We analyzed the incidence and cause of glenohumeral osteoarthritis including its early stage with plain radiographs. In Kishiwada City Hospital we treated 4035 patients with orthopaedic complications in 1995. A total of 345 patients (390 shoulders) had shoulder diseases. The patients with primary glenohumeral osteoarthritis were 2 men and 14 women (18 shoulders) aged 60 to 86 years (mean 71.9 years), and 2 cases were secondary osteoarthritis. In 2 cases (3 shoulders) of severe osteoarthritis other joints were also affected. Only 4 (25%) of the patients with primary glenohumeral osteoarthritis had osteoarthritic changes only in the glenohumeral joint. The incidence of primary glenohumeral osteoarthritis was 0.4% in the patients with orthopaedic complications and 4.6% in the patients who had shoulder diseases. Women were more likely to have primary glenohumeral osteoarthritis than men, and patients older than 60 years of age were more likely to have it than younger patients.

Proteoglycans in the synovial fluid of the temporomandibular joint as an indicator of changes in cartilage metabolism during primary and secondary osteoarthritis

PURPOSE

The specific aim of this investigation was to assess differences between primary and secondary osteoarthritis (OA) of the temporomandibular joint (TMJ) using clinical evaluation and synovial fluid analysis for proteoglycans.

MATERIALS AND METHODS

Arthroscopic surgery was performed on 101 TMJs from patients with significant pain or dysfunction and who had failed to respond to treatment. Joints were assessed for primary and secondary osteoarthritis. Synovial fluid aspirates were obtained and analyzed to determine the levels of keratan sulfate (KS) epitope and a novel 3B3(-) epitope by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Fifty-four patients and 67 joints had OA diagnosed by both clinical examination and arthroscopy. Primary OA was diagnosed in 14 joints (20%), and the remaining 53 joints were regarded as having secondary OA. No differences were detected in the levels of KS in the synovial fluid from the primary and secondary OA joints. Furthermore, the 3B3(-) epitope was not detectable in the synovial fluid aspirates of any TMJ.

CONCLUSION

Secondary OA is a common disorder of the TMJ. However, there is no apparent difference in the metabolism of the joints with primary and secondary OA as assessed by proteoglycans in the synovial fluid. The apparent absence of the 3b3(-) epitope, in contrast to its presence in OA of other major synovial joints, suggests that there are some differences between the cartilage metabolism of the TMJ and these other joints during OA.