Calcific tendonitis : a model

Calcification alters the viscoelastic properties of tendon fascicle bundles depending on matrix content

Tendon fascicle bundles are often used as biological grafts and thus must meet certain quality requirements, such as excluding calcification, which alters the biomechanical properties of soft tissues. In this work, we investigate the influence of early-stage calcification on the mechanical and structural properties of tendon fascicle bundles with varying matrix content. The calcification process was modeled using sample incubation in concentrated simulated body fluid. Mechanical and structural properties were investigated using uniaxial tests with relaxation periods, dynamic mechanical analysis, as well as magnetic resonance imaging and atomic force microscopy. Mechanical tests showed that the initial phase of calcification causes an increase in the elasticity, storage, and loss modulus, as well as a drop in the normalized value of hysteresis. Further calcification of the samples results in decreased modulus of elasticity and a slight increase in the normalized value of hysteresis. Analysis via MRI and scanning electron microscopy showed that incubation alters fibrillar relationships within the tendon structure and the flow of body fluids. In the initial stage of calcification, calcium phosphate crystals are barely visible; however, extending the incubation time for the next 14 days results in the appearance of calcium phosphate crystals within the tendon structure and leads to damage in its structure. Our results show that the calcification process modifies the collagen-matrix relationships and leads to a change in their mechanical properties. These findings will help to understand the pathogenesis of clinical conditions caused by calcification process, leading to the development of effective treatments for these conditions. STATEMENT OF SIGNIFICANCE: This study investigates how calcium mineral deposition in tendons affects their mechanical response and which processes are responsible for this phenomenon. By analyzing the elastic and viscoelastic properties of animal fascicle bundles affected by calcification induced via incubation in concentrated simulated body fluid, the study sheds light on the relationship between structural and biochemical changes in tendons and their altered mechanical response. This understanding is crucial for optimizing tendinopathy treatment and preventing tendon injury. The findings provide insights into the calcification pathway and its resulting changes in the biomechanical behaviors of affected tendons, which have been previously unclear.

Hydroxyapatite crystal deposition disease around the hip: a rare cause of piriformis syndrome and ischiofemoral impingement

Hydroxyapatite crystal deposition disease (HADD) around the hip is typically described involving the gluteal tendons. However, HADD can occur in any location and result in varied clinical presentations. Even with small deposits, symptoms can be significant and imaging findings may appear aggressive, mimicking infection and malignancy particularly when in an atypical location.

We illustrate cases of both common and rare locations of HADD around the hip, in particular presenting as greater trochanteric pain syndrome, piriformis syndrome and ischiofemoral impingement. The latter two manifestations have not been previously described in the literature.

Low signal deposits were identified on MRI at the greater trochanter (gluteus medius tendon), proximal piriformis (adjacent to the sciatic nerve), and quadratus femoris (in the ischiofemoral space), respectively. Associated inflammatory changes with tendinopathy, bursitis and oedema were also demonstrated. The patient with piriformis syndrome underwent steroid injections and shockwave therapy with significant symptom improvement.

HADD should be within the differential diagnosis for hip pain and nerve compression syndromes. Knowledge of tendon anatomy and correlation with radiographs or CT, even after MRI, is crucial in recognising unusual manifestations and preventing unnecessary investigation. Therefore, we review the spectrum of imaging features of HADD, as well as the current evidence on its management, to confidently diagnose this condition.

Extracorporeal shock wave therapy mechanisms in musculoskeletal regenerative medicine

Extracorporeal shockwave therapy (ESWT) is a popular non-invasive therapeutic modality in the medical field for the treatment of numerous musculoskeletal disorders. This technique first emerged around the 1980s as extracorporeal shockwave lithotripsy and has been studied since then for its application towards orthopedics and traumatology. ESWT works by the emission of acoustic waves (shockwaves) that carry energy and can propagate through tissues. Shockwaves can generate interstitial and extracellular responses, producing many beneficial effects such as: pain relief, vascularization, protein biosynthesis, cell proliferation, neuro and chondroprotection, and destruction of calcium deposits in musculoskeletal structures. The combination of these effects can lead to tissue regeneration and significant alleviation of pain, improving functional outcomes in injured tissue. Considering these facts, ESWT shows great potential as a useful regenerative medicine technique for the treatment of numerous musculoskeletal injuries.

Pathological Mineralization: The Potential of Mineralomics

Pathological mineralization has been reported countless times in the literature and is a well-known phenomenon in the medical field for its connections to a wide range of diseases, including cancer, cardiovascular, and neurodegenerative diseases. The minerals involved in calcification, however, have not been directly studied as extensively as the organic components of each of the pathologies. These have been studied in isolation and, for most of them, physicochemical properties are hitherto not fully known. In a parallel development, materials science methods such as electron microscopy, spectroscopy, thermal analysis, and others have been used in biology mainly for the study of hard tissues and biomaterials and have only recently been incorporated in the study of other biological systems. This review connects a range of soft tissue diseases, including breast cancer, age-related macular degeneration, aortic valve stenosis, kidney stone diseases, and Fahr’s syndrome, all of which have been associated with mineralization processes. Furthermore, it describes how physicochemical material characterization methods have been used to provide new information on such pathologies. Here, we focus on diseases that are associated with calcium-composed minerals to discuss how understanding the properties of these minerals can provide new insights on their origins, considering that different conditions and biological features are required for each type of mineral to be formed. We show that mineralomics, or the study of the properties and roles of minerals, can provide information which will help to improve prevention methods against pathological mineral build-up, which in the cases of most of the diseases mentioned in this review, will ultimately lead to new prevention or treatment methods for the diseases. Importantly, this review aims to highlight that chemical composition alone cannot fully support conclusions drawn on the nature of these minerals.

Complications of calcific tendinitis of the shoulder: a concise review

Calcific tendinitis (CT) of the rotator cuff (RC) muscles in the shoulder is a disorder which remains asymptomatic in a majority of patients. Once manifested, it can present in different ways which can have negative effects both socially and professionally for the patient. The treatment modalities can be either conservative or surgical. There is poor literature evidence on the complications of this condition with little consensus on the treatment of choice. In this review, the literature was extensively searched in order to study and compile together the complications of CT of the shoulder and present it in a clear form to ease the understanding for all the professionals involved in the management of this disorder. Essentially there are five major complications of CT: pain, adhesive capsulitis, RC tears, greater tuberosity osteolysis and ossifying tendinitis. All the above complications have been explained right from their origin to the control measures required for the relief of the patient.

LEVEL OF EVIDENCE

5.

Smoking and morphology of calcific deposits affect the outcome of needle aspiration of calcific deposits (NACD) for calcific tendinitis of the rotator cuff

INTRODUCTION

Although NACD has proven to be an effective minimal invasive treatment for calcific tendinitis of the rotator cuff, little is known about the factors associated with treatment failure or the need for multiple procedures.

METHODS

Patients with symptomatic calcific tendinitis who were treated by NACD were evaluated in a retrospective cohort study. Demographic details, medical history, sonographic and radiographic findings were collected from patient files. Failure of NACD was defined as the persistence of symptoms after a follow-up of at least six months. NACD procedures performed within six months after a previous NACD procedure were considered repeated procedures. Multivariate logistic regression analysis was used to determine factors associated with treatment failure and multiple procedures.

RESULTS

431 patients (277 female; mean age 51.4±9.9 years) were included. Smoking (adjusted odds ratio (AOR): 1.7, 95% CI 1.0-2.7, p=0.04) was significantly associated with failure of NACD. Patients with Gärtner and Heyer (GH) type I calcific deposits were more likely to need multiple NACD procedures (AOR: 3.4, 95% CI 1.6-7.5, p<0.01) compared to patients with type III calcific deposits. Partial thickness rotator cuff tears were of no influence on the outcome of NACD or the number of treatments necessary.

CONCLUSION

Smoking almost doubled the chance of failure of NACD and the presence of GH type I calcific deposits significantly increased the chance of multiple procedures. Partial thickness rotator cuff tears did not seem to affect the outcome of NACD. Based on the findings in this study, the importance of quitting smoking should be emphasized prior to NACD and partial thickness rotator cuff tears should not be a reason to withhold patients NACD.

Differences between the cell populations from the peritenon and the tendon core with regard to their potential implication in tendon repair

The role of intrinsic and extrinsic healing in injured tendons is still debated. In this study, we characterized cell plasticity, proliferative capacity, and migration characteristics as proxy measures of healing potential in cells derived from the peritenon (extrinsic healing) and compared these to cells from the tendon core (intrinsic healing). Both cell populations were extracted from horse superficial digital flexor tendon and characterized for tenogenic and matrix remodeling markers as well as for rates of migration and replication. Furthermore, colony-forming unit assays, multipotency assays, and real-time quantitative polymerase chain reaction analyses of markers of osteogenic and adipogenic differentiation after culture in induction media were performed. Finally, cellular capacity for differentiation towards a myofibroblastic phenotype was assessed. Our results demonstrate that both tendon- and peritenon-derived cell populations are capable of adipogenic and osteogenic differentiation, with higher expression of progenitor cell markers in peritenon cells. Cells from the peritenon also migrated faster, replicate more quickly, and show higher differentiation potential toward a myofibroblastic phenotype when compared to cells from the tendon core. Based on these data, we suggest that cells from the peritenon have substantial potential to influence tendon-healing outcome, warranting further scrutiny of their role.

Patellar tendinopathy: preliminary surgical results

Background:

Calcific deposits (CaDs) may be related to chronic postoperative pain and may affect function after patellar tendon surgery.

Study Design:

Cross-sectional.

Hypothesis:

We hypothesized that patients with CaDs (+CaDs) would rate lower than those without (−CaDs) on measures of knee function and quality of life.

Methods:

Patients completed the Tegner Lysholm Knee Scoring Scale (Lysholm), Knee Injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee Subjective Knee Form (IKDC), and the Tegner Activity Level Scale. Sixteen postsurgical and 16 age-matched controls were tested. Patients +CaDs were 5.6 years older than those patients −CaDs and had 4.2 years of longer elapse since surgery. Bilateral patellar tendons were examined for CaDs with musculoskeletal ultrasound imaging. One-way analysis of variance was used to determine if differences existed among patients +CaDs and −CaDs and healthy controls. Hierarchical logistic regressions were used to determine which variables best predicted the presence of CaDs.

Results:

CaDs were found in 44% (7 of 16) of postsurgical patients, who scored lower than controls on all dimensions of the Lysholm, KOOS, and IKDC. Patients +CaD had lower KOOS scores than controls (symptoms, activities of daily living, and quality of life). Age and time since surgery were both moderately related to the presence of CaDs, and both correctly predicted 71% of patients +CaDs.

Conclusion:

Calcific deposits were found in the patellar tendon of 44% of postsurgical patients, who rated themselves lower on all subjective measures of knee function and quality of life following surgery. Age is an important factor for developing CaDs postsurgery.

Clinical Relevance:

Calcific deposits may be present in patellar tendons following surgery, but their direct role in functional or clinical limitations remains unknown.

Tendon gradient mineralization for tendon to bone interface integration

Tendon-to-bone integration is a great challenge for tendon or ligament reconstruction regardless of use of autograft or allograft tendons. We mineralized the tendon, thus transforming the tendon-to-bone into a "bone-to-bone" interface for healing. Sixty dog flexor digitorum profundus (FDP) tendons were divided randomly into five groups: (1) normal FDP tendon, (2) CaP (non-extraction and mineralization without fetuin), (3) CaPEXT (Extraction by Na2 HPO4 and mineralization without fetuin), (4) CaPFetuin (non-extraction and mineralization with fetuin), and (5) CaPEXTFetuin (extraction and mineralization with fetuin). The calcium and phosphate content significantly increased in tendons treated with combination of extraction and fetuin compared to the other treatments. Histology also revealed a dense mineral deposition throughout the tendon outer layers and penetrated into the tendon to a depth of 200 µm in a graded manner. Compressive moduli were significantly lower in the four mineralized groups compared with normal control group. No significant differences in maximum failure strength or stiffness were found in the suture pull-out test among all groups. Mineralization of tendon alters the interface from tendon to bone into mineralized tendon to bone, which may facilitate tendon-to-bone junction healing following tendon or ligament reconstruction.

Physiopathology of intratendinous calcific deposition

In calcific tendinopathy (CT), calcium deposits in the substance of the tendon, with chronic activity-related pain, tenderness, localized edema and various degrees of decreased range of motion. CT is particularly common in the rotator cuff, and supraspinatus, Achilles and patellar tendons. The presence of calcific deposits may worsen the clinical manifestations of tendinopathy with an increase in rupture rate, slower recovery times and a higher frequency of post-operative complications. The aetiopathogenesis of CT is still controversial, but seems to be the result of an active cell-mediated process and a localized attempt of the tendon to compensate the original decreased stiffness. Tendon healing includes many sequential processes, and disturbances at different stages of healing may lead to different combinations of histopathological changes, diverting the normal healing processes to an abnormal pathway. In this review, we discuss the theories of pathogenesis behind CT. Better understanding of the pathogenesis is essential for development of effective treatment modalities and for improvement of clinical outcomes.

Hyperglycemia reduces proteoglycan levels in tendons

RATIONALE

Diabetic tendinopathy is characterized by increased stiffness, thickness, and excess calcification of affected tendons. We investigated the hypothesis that proteoglycans (PGs), as key regulators of tendon structure and calcification, are altered in diabetic tendons.

METHODS

Adult porcine patellar tendons were incubated in iso-osmolar media with high or normal glucose levels for 2 weeks. The PG fraction was isolated and analyzed. Protein and mRNA levels of five PGs were measured. PG production was assessed in primary tenocyte monolayers by (35)S-sulfate labeling in high and normal glucose conditions with and without exposure to advanced glycation end-products (AGEs). Levels of transforming growth factor β, which commonly mediates some effects of hyperglycemia, were also measured and the effects of free radical scavengers on (35)S-sulfate incorporation were determined.

RESULTS

PG levels were significantly decreased in tendons exposed to high glucose media compared with tendons in iso-osmolar control media. Relative quantities of individual PGs were unchanged by exposure to hyperglycemia and mRNAs for PGs were variably affected. High glucose media decreased PG production by tenocytes as measured by (35)S-sulfate labeling, whereas AGE-modified type I collagen and free radical scavengers had no effects. Hyperglycemic conditions increased levels of transforming growth factor β1 in an AGE-independent manner.

CONCLUSIONS

Hyperglycemia produces a reduction in PG levels related to decreased synthesis or sulfation of glycosaminoglycans, which may contribute to the tendon pathology observed clinically in diabetes.

Calcific tendonitis of the tibialis posterior tendon at the navicular attachment

Calcific tendinosis (tendonosis/tendonitis) is a condition which results from the deposition of calcium hydroxyapatite crystals in any tendon of the body. Calcific tendonitis usually presents with pain, which can be exacerbated by prolonged use of the affected tendon. We report a case of calcific tendinosis in the posterior tibialis tendon at the navicular insertion. The pathology is rare in the foot, and extremely rare in the tibialis posterior tendon, indeed there are only 2 reported in the published literature. This case report highlights the need to consider calcific tendinosis in the foot despite its rarity. If this diagnosis is considered early, appropriate investigations can then be requested and unnecessary biopsies, use of antibiotics and surgery can be avoided. We also discuss possible causes of calcific tendinosis in the tibialis posterior tendon, the role of imaging modalities and review treatment methods.

Tenosynovitis with psammomatous calcification: a poorly recognized pseudotumor related to repetitive tendinous injury

Tenosynovitis with psammomatous calcification, described in 1983 by Gravanis and Gaffney, is a distinctive clinicopathologic variant of "idiopathic calcifying tenosynovitis" or "calcific tendonitis." However, tenosynovitis with psammomatous calcification is poorly recognized by pathologists and for this reason has not been adopted widely as a distinct entity. We present the clinicopathologic features of 6 cases of tenosynovitis with psammomatous calcification. Cases involved the tendons, peritendinous soft tissues, and adjacent synovium of the distal extremities (3 fingers, 2 feet, and 1 carpal tendon) of women who ranged in age from 16 to 83 years (mean 48 y). The lesions presented a painful mass. A history of occupational or sports-related repetitive motion and/or persistent mild trauma was noted in all patients. No patient had a history of hyperphosphatemia. All lesions were treated by surgical excision and described clinically as variably cystic nodules composed of amorphous "cheese-like" debris. Histologically, the lesions were centered in the tendon or peritendinous soft tissue and composed of a mixed (myo) fibroblastic and histiocytic proliferation in association with a degenerating tendinous tissue, which was undergoing dystrophic calcification, with the formation of distinctive psammoma body-like spheroidal bodies. The clinical and morphologic characteristics of tenosynovitis with psammomatous calcification (distal location, absent hyperphosphatemia, and psammomatous calcifications) differ from those of typical idiopathic calcifying tenosynovitis/calcific tendinitis (proximal location and dystrophic tendinous calcification) and tumoral calcinosis (hyperphosphatemia and amorphous soft tissue calcification), and it should be recognized as a distinct clinicopathologic entity. Improved recognition of these unique features by pathologists should allow ready diagnosis of this unusual pseudotumor in most instances.

Calcific tendinitis: a pictorial review

Calcific tendinitis is caused by the pathologic deposition of calcium hydroxyapatite crystals in tendons and is a common cause of joint pain. The disease typically affects the shoulder and hip, with characteristic imaging findings; however, any joint can be involved. Occasionally, calcific tendinitis can mimic aggressive disorders, such as infection and neoplasm, especially on magnetic resonance imaging. Radiologists should be familiar with the imaging findings to distinguish calcific tendinitis from more aggressive processes. Image-guided percutaneous needle aspiration and steroid injection of calcific tendinitis are useful techniques performed by the radiologist for the treatment of symptomatic cases. Familiarity with these procedures and their imaging appearance is an important aspect in the management of this common disease.

Association between ultrasonographic findings and bone/cartilage biomarkers in patients with early-stage knee osteoarthritis

Little is known regarding the association between ultrasonographic (US) findings and biomarkers of bone and cartilage in individuals with knee osteoarthritis (OA). We investigated (1) US findings in early-stage knee OA and (2) the association between US findings and bone/cartilage biomarkers. A population cohort aged 35-55 years (n = 106) with early-stage knee OA was investigated. US examination was performed according to European League against Rheumatism (EULAR) guidelines using a 7.5-MHz probe. Biomarkers of bone resorption (CTx-I) and formation (PINP), cartilage resorption (U-CTx-II) and synthesis (S-PIIANP), and general bone and cartilage biomarkers (OC, COMP) were assessed. The most prevalent US findings were tendon calcification, synovial thickening, and suprapatellar effusion. In women, the presence of tendon calcification and Baker's cysts could predict 36% of the variability in U-CTx-II levels. The presence of osteophytes and tendon calcification predicted up to 38% of the variability of PIIANP concentration. Defects in subchondral bone, meniscal changes, and effusion predicted up to 29% of the variability in COMP levels. Tendon calcification was related to cartilage synthesis (based on PIIANP levels) in men and to cartilage degradation (based on U-CTx-II concentrations) in women. US signs of synovitis were reflected metabolically by markers of joint tissue metabolism. Tendon calcification, synovial thickening, and effusion were common US findings in early-stage knee OA. US-detectable findings were substantially responsible for the variability in bone and cartilage biomarkers, associations reflective of the active metabolism of soft tissues in early-stage OA.