Tendinopathic supraspinatus tenocytes may have a neuroendocrine-like function, secreting CGRP, SP and VEGF: a pilot immunohistochemistry study

We wanted to observe and compare the appearance of neurovascular tissue from tendon ex vivo, in patients with and without painful rotator cuff tendinopathy. Supraspinatus tendons were biopsied from 5 participants with painful tendinopathy and normal tendon from a young male. Slides were stained with haematoxylin and eosin and toluidine blue for histological assessment. Immunohistochemical markers for general nerves (protein gene-product 9.5 and synaptophysin), sensory nerves (calcitonin gene-related peptide; substance-P) and vascularisation (vascular endothelial growth factor) were used. PGP9.5 and CGRP-immunoreactive fibres were associated with vessels in cases and control. Synaptophysinlabelled fibres were observed in close relation to vessels in tendinopathy. PGP9.5, CGRP, SP and VEGF-immunoreaction also labelled tenocyte-like cells in degenerative areas and fibres in regions of fat and collagen. Sensory innervation and vascularity are increased in tendinopathy. The evidence for innervation and vascularity of symptomatic rotator cuff tendon may aid the development of novel investigations and therapies in the management of patients with this ailment.

Dynamic contrast-enhanced MR imaging and histopathology in chronic achilles tendinosis: A longitudinal MR study of 15 patients

Purpose: To evaluate the value of dynamic contrast-enhanced MR imaging (DEMRI) and its correlation to symptoms and histopathology in chronic Achilles tendinosis.

Material and Methods: Fifteen patients with severe symptoms underwent DEMRI preoperatively and 2 years postoperatively. US-guided core biopsies of tendinosis tissue were obtained preoperatively and the specimens were analyzed using a semiquantitative protocol. DEMRI was evaluated by calculating the area under curve (AUC) of signal alteration and the static MR by a semiquantitative grading scale. A questionnaire and clinical examination evaluated the clinical outcome.

Results: Early contrast enhancement (first 72 s) was seen in DEMRI at tendon lesions of the symptomatic Achilles tendons with a significant difference to asymptomatic contralateral tendon that revealed no or mild enhancement. Increased severity of tendon pathology (including fiber structure abnormality, increased vascularity, rounding of nuclei and increased amount of glycosaminoglycans) was correlated to both dynamic and static signal enhancement. Two years following surgical treatment, the signal alterations showed regression of early contrast enhancement (AUC decreased from 9 preoperatively to 2 postoperatively). The clinical outcome was as follows: 8 patients excellent, 4 good, 2 fair and 1 poor.

Conclusion: Patients with chronic painful achillodynia showed an early contrast-agent enhancement corresponding to the tendon lesion. Increased enhancement correlated to increased severity of tendon histopathology and patient symptoms. Two years after surgical treatment the contrast-agent enhancement decreased.

Dose-Related and Time-Dependent Development of Collagenase-Induced Tendinopathy in Rats

Tendinopathy is a big burden in clinics and it represents 45% of musculoskeletal lesions. Despite the relevant social impact, both pathogenesis and development of the tendinopathy are still under-investigated, thus limiting the therapeutic advancement in this field. The purpose of this study was to evaluate the dose-dependent and time-related tissue-level changes occurring in a collagenase-induced tendinopathy in rat Achilles tendons, in order to establish a standardized model for future pre-clinical studies. With this purpose, 40 Sprague Dawley rats were randomly divided into two groups, treated by injecting collagenase type I within the Achilles tendon at 1 mg/mL (low dose) or 3 mg/mL (high dose). Tendon explants were histologically evaluated at 3, 7, 15, 30 and 45 days. Our results revealed that both the collagenase doses induced a disorganization of collagen fibers and increased the number of rounded resident cells. In particular, the high dose treatment determined a greater neovascularization and fatty degeneration with respect to the lower dose. These changes were found to be time-dependent and to resemble the features of human tendinopathy. Indeed, in our series, the acute phase occurred from day 3 to day 15, and then progressed towards the proliferative phase from day 30 to day 45 displaying a degenerative appearance associated with a very precocious and mild remodeling process. The model represents a good balance between similarity with histological features of human tendinopathy and feasibility, in terms of tendon size to create lesions and costs when compared to other animal models. Moreover, this model could contribute to improve the knowledge in this field, and it could be useful to properly design further pre-clinical studies to test innovative treatments for tendinopathy.

[Conservative treatment of tendinopathies of upper limbs in occupational health: a literature review]

BACKGROUND

In the last few years, the incidence of upper limbs tendon injuries has seen a dramatic increase among workers. Conservative treatment is the first choice to relieve symptoms, allowing a safe return to work. However, the scientific evidence of its  efficacy is widely debated.

OBJECTIVE AND METHODS

Research and literature review on the efficacy of conservative treatment of upper limbs tendon injuries in occupational settings.

RESULTS

A total of 271 references were found on Medline and Embase up to May 2015. 116 papers were excluded, 155 articles were included and the full text read.

CONCLUSIONS

After a timely diagnosis, a prompt start of the rehabilitation programme and a limitation of complete rest are useful to relieve pain, increase functionality and reduce work absenteeism in the long term. Conservative treatment combinations, such as manual therapy, specific exercises focused on increasing flexibility and muscle strength and specific-gesture training, achieves more significant results than a single isolated treatments. Currently, there is no strong scientific evidence to support prolotherapy and Platelet-Rich Plasma (PRP). However, current promising results will encourage further studies. Awareness among both employers and employees about prevention and risk factors should be enhanced.

The effect of glenoid cavity depth on rotator cuff tendinitis

INTRODUCTION

Some of the most important causes of shoulder pain are inflammation and degenerative changes in the rotator cuff (RC). Magnetic resonance imaging (MRI) is a noninvasive and safe imaging modality. MRI can be used for the evaluation of cuff tendinopathy. In this study, we evaluated the relationship between glenoid cavity depth and cuff tendinopathy and we investigated glenoid cavity depth on the pathogenesis of cuff tendinopathy.

MATERIALS AND METHODS

We retrospectively evaluated 215 patients who underwent MRI. Of these, 60 patients showed cuff tendinopathy (group A) and 54 patients showed no pathology (group B). Glenoid cavity depth was calculated in the coronal and transverse planes.

RESULTS

The mean axial depth was 1.7 ± 0.9 and the mean coronal depth 3.8 ± 0.9, for group A. The mean axial depth was 3.5 ± 0.7 and the mean coronal depth 1.5 ± 0.8, for group B. There were significant differences in the axial and coronal depths between the two groups.

CONCLUSION

High coronal and low axial depth of the glenoid cavity can be used to diagnose RC tendinitis.

Creating an Animal Model of Tendinopathy by Inducing Chondrogenic Differentiation with Kartogenin

Previous animal studies have shown that long term rat treadmill running induces over-use tendinopathy, which manifests as proteoglycan accumulation and chondrocytes-like cells within the affected tendons. Creating this animal model of tendinopathy by long term treadmill running is however time-consuming, costly and may vary among animals. In this study, we used a new approach to develop an animal model of tendinopathy using kartogenin (KGN), a bio-compound that can stimulate endogenous stem/progenitor cells to differentiate into chondrocytes. KGN-beads were fabricated and implanted into rat Achilles tendons. Five weeks after implantation, chondrocytes and proteoglycan accumulation were found at the KGN implanted site. Vascularity as well as disorganization in collagen fibers were also present in the same site along with increased expression of the chondrocyte specific marker, collagen type II (Col. II). In vitro studies confirmed that KGN was released continuously from KGN-alginate in vivo beads and induced chondrogenic differentiation of tendon stem/progenitor cells (TSCs) suggesting that chondrogenesis after KGN-bead implantation into the rat tendons is likely due to the aberrant differentiation of TSCs into chondrocytes. Taken together, our results showed that KGN-alginate beads can be used to create a rat model of tendinopathy, which, at least in part, reproduces the features of over-use tendinopathy model created by long term treadmill running. This model is mechanistic (stem cell differentiation), highly reproducible and precise in creating localized tendinopathic lesions. It is expected that this model will be useful to evaluate the effects of various topical treatments such as NSAIDs and platelet-rich plasma (PRP) for the treatment of tendinopathy.

Combined Tendon and Bone Allograft Transplantation for Chronic Achilles Tendon Ruptures

Combined flexor hallucis longus tendon transfer and bone-tendon allograft transplantation is a reasonable option for advanced distal-segment Achilles tendinopathy. This procedure provides anatomic restoration and improved function of the posterior muscle group without sacrificing the regional anatomy. Allograft transplantation is safe and does not require immunosuppressive therapy. The soft tissue envelope should be healthy because wound complications can be an issue. This procedure is especially helpful in patients with significant disability.

The extensor carpi ulnaris pseudolesion: evaluation with microCT, histology, and MRI

OBJECTIVE

To determine if magic angle plays a role in apparent central increased signal intensity of the distal extensor carpi ulnaris tendon (ECU) on MRI, to see if histologic findings of tendon degeneration are associated with increased T1 or T2 tendon signal on MR imaging, and to determine the prevalence of the ECU "pseudolesion".

MATERIALS AND METHODS

A standard 3 Tesla protocol was utilized to scan ten cadaveric wrists. A 40 mm length of 10 ECU and four extensor carpi radialis brevis (ECRB) tendons were immersion fixed before microCT scanning. Staining with Alcian blue, Masson's trichrome and Safranin O was performed before light microscopy. Fifty clinical wrist MRIs were also reviewed for the presence of increased T1 and/or T2 signal.

RESULTS

Central increased T1 and/or T2 signal was observed in 9 of 10 cadaveric ECU tendons, but not in ECRB tendons. MicroCT and histology showed inter-tendinous matrix between the two distal heads of the ECU. Increased mucoid degeneration correlated with increased MRI signal intensity. The tendon fibers were at a maximum of 8.39° to the longitudinal axis on microCT. Clinical MRIs showed increased T1 signal in 6%, increased T2 signal in 8%, increased T1 and T2 signal in 80%, and 6% showing no increased signal.

CONCLUSION

Central increased T1 and/or T2 signal in the ECU tendon indicates the presence of normal inter-tendinous ground substance, with increased proteoglycan content (mucoid degeneration) responsible for increased signal intensity. None of the fibers were shown on microCT to approach the magic angle.

MRI Findings Associated with Recalled Modular Femoral Neck Rejuvenate and ABG Implants

MARS-MRI is suggested for the diagnosis of adverse local tissue reactions (ALTR) in patients with recalled femoral stems with modular necks, but there has been no major study looking at MARS-MRI findings in this population. A retrospective review was performed on 312 patients who received a modular neck hip implant between October 2007 and February 2012. 62% of patients had intra-articular effusions, with 27% containing debris. Extra-capsular effusions were present in 35% of hips. 54% had synovitis and 5.4% had osteolysis. Tendinopathy and tendon disruption was present in the gluteus medius (58%/12%), hamstring (56%/12%), gluteus minimus (38%/7.7%) and iliopsoas (7.1%/4.8%). Abnormal MARS-MRI findings are associated with modular neck femoral components and can suggest underlying ALTR. MARS-MRI abnormalities merit serious consideration in this population.

Dual functional core-sheath electrospun hyaluronic acid/polycaprolactone nanofibrous membranes embedded with silver nanoparticles for prevention of peritendinous adhesion

Peritendinous adhesions, one of the common complications after tendon injury and subsequent surgery, could be minimized by directly placing a physical barrier between the injured site and the surrounding tissue. We used silver (Ag) nanoparticles embedded in electrospun hyaluronic acid (HA)/polycaprolactone (PCL) nanofibrous membranes (NFMs) (HA/PCL+Ag NFMs) to prevent peritendinous adhesions and bacterial infection after tendon surgery. HA was used for effective lubrication, and Ag provided antibacterial activity. A dual functional anti-adhesion barrier with core-sheath nanofibrous architecture was made from an HA core solution and a photo-reduced silver nitrate/PCL sheath solution. Polycaprolactone NFMs (PCL NFMs), hyaluronic acid/polycaprolactone core-sheath NFMs (HA/PCL NFMs) and HA/PCL+Ag NFMs with comparable fiber diameters and pore sizes were prepared and analyzed. The microporous structure of NFMs is expected to effectively block the penetration of adhesion-forming fibroblasts during tendon healing. The release of Ag from HA/PCL+Ag NFMs plateaued after 4 days, which confirmed the short-term anti-bacterial effect, and this result was verified with agar diffusion tests. In contrast, the release of HA was extended up to 21 days to simulate the lubrication effect offered by HA in the synovial fluid of the tendon sheath. In vitro cell culture experiments revealed that HA/PCL+Ag NFMs exhibited the highest inhibition of fibroblast attachment and proliferation without significant cytotoxicity due to the synergistic effect of Ag and HA. In vivo studies with a rabbit flexor tendon model further confirmed the efficacy of HA/PCL+Ag NFMs in reducing peritendinous adhesion as determined by gross observation, histology, joint range-of-motion, tendon gliding and biomechanical tests.

Management of rotator cuff calcific tendinosis guided by ultrasound elastography

BACKGROUND

Ultrasound (US) elastography can provide information about the hardness of calcification and might help decide treatment strategy. The purpose of this study was to evaluate the hardness of the calcific area within rotator cuffs by US elastography as an aid for the selection of aspiration or fine-needle repeated puncture for the treatment of rotator cuff calcific tendinosis.

METHODS

This prospective study included 39 patients (32 males, 7 females; mean age, 52.9 years) who received US elastography and gray-scale ultrasonography before US-guided treatment for rotator cuff calcific tendinosis. The morphology of the calcifications was classified as arc, fragmented, nodular, and cystic types. US elastography using virtual touch imaging (acoustic radiation force impulse) technique was performed to examine the calcified region to obtain an elastogram that was graded dark, intermediate, or bright. The hardness of the calcifications were recorded, and graded as hard, sand-like, or fluid-like tactile patterns during the US-guided treatment, and the tactile patterns were compared with the results of US elastography and gray-scale ultrasonography.

RESULTS

Though the morphologies of the calcifications were significantly related to the tactile pattern of the needle punctures (p < 0.001), gray-scale US could not accurately demonstrate the hardness of the calcifications. With the aid of elastography, the fluid-like tactile pattern could be predicted well as a nondark pattern by elastography (p < 0.001).

CONCLUSION

Ultrasound elastography is a useful modality for evaluation of rotator cuff calcific tendinosis, and as an aid to guide management. If elastography shows the calcified area as a non-dark pattern, then fine-needle aspiration should be performed.

Imaging of the Rotator Cuff With Optical Coherence Tomography

This study evaluated the utility of optical coherence tomography (OCT) in imaging porcine and human rotator cuff (RTC) tissue, analyzed its effectiveness in identifying clinical pathology, and correlated these findings with histologic examination. Twelve human cadaveric and 6 porcine shoulders were evaluated. Six-millimeter-wide bone sections were harvested from the proximal humerus of each specimen, with each containing the entire enthesis of the respective RTC tendon, as well as 2 cm of tendon medial to the enthesis. Only the supraspinatus tendon was evaluated in the human specimens, whereas the enthesis of multiple RTC tendons were evaluated in the porcine model. All specimens were imaged using OCT and correlated with histologic evaluation. Optical coherence tomography evaluation of macroscopically healthy tissue consistently showed an easily identifiable banding pattern (birefringence) in contrast to a disorganized, homogeneous appearance in grossly diseased tissue. Optical coherence tomography was more effective for qualitative evaluation of RTC tissue, identification of bursal-sided RTC tears, and localization of calcific deposits, whereas intrasubstance tendon delaminations and partial articular-sided tendon avulsion lesions were relatively more difficult to identify. Optical coherence tomography correlated well with histologic evaluation in all specimens. Optical coherence tomography provides high-resolution, subsurface imaging of rotator cuff tissue in real-time to a depth of up to 4 mm with excellent correlation to histology in a cadaveric model. Optical coherence tomography could be an effective adjunctive tool for the identification and localization of rotator cuff pathology. The use of OCT in arthroscopic shoulder surgery potentially provides a minimally invasive modality for qualitative assessment of rotator cuff pathology. This may allow for a decrease in soft tissue dissection, improved qualitative assessment of cuff tissue, and improved patient outcomes.

Negative Poisson's ratios in tendons: An unexpected mechanical response

Tendons are visco-elastic structures that connect bones to muscles and perform the basic function of force transfer to and from the skeleton. They are essential for positioning as well as energy storing when involved in more abrupt movements such as jumping. Unfortunately, they are also prone to damage, and when injuries occur, they may have dilapidating consequences. For instance, there is consensus that injuries of tendons such as Achilles tendinopathies, which are common in athletes, are difficult to treat. Here we show, through in vivo and ex vivo tests, that healthy tendons are highly anisotropic and behave in a very unconventional manner when stretched, and exhibit a negative Poisson's ratio (auxeticity) in some planes when stretched up to 2% along their length, i.e. within their normal range of motion. Furthermore, since the Poisson's ratio is highly dependent on the material's microstructure, which may be lost if tendons are damaged or diseased, this property may provide a suitable diagnostic tool to assess tendon health.

STATEMENT OF SIGNIFICANCE

We report that human tendons including the Achilles tendons exhibits the very unusual mechanical property of a negative Poisson's ratio (auxetic) meaning that they get fatter rather than thinner when stretched. This report is backed by in vivo and ex vivo experiments we performed which clearly confirm auxeticity in this living material for strains which correspond to those experienced during most normal everyday activities. We also show that this property is not limited to the human Achilles tendon, as it was also found in tendons taken from sheep and pigs. This new information about tendons can form the scientific basis for a test for tendon health as well as enable the design of better tendon prosthesis which could replace damaged tendons.

The effects of substance p on tendinopathy are dose-dependent: an in vitro and in vivo model study

OBJECTIVES

Substance P (SP) is known to be involved in neuropathic pain, chronic inflammation, and tendinopathy. The present study evaluated the effects of different doses of SP on tendon-derived stem cells (TDSCs) in vitro and tendons in vivo.

METHODS

For the in vitro study, TDSCs cultured in growth medium with different concentrations of SP (negative control, 0.1 nM, and 1.0 nM). The effects of SP on TDSCs were examined with respect to their ability to proliferate and differentiate. For the in vivo study, we injected different doses of SP (saline control, 0.5 nmol, and 5.0 nmol) into rat patella tendons to investigate the effects of SP on tendons.

RESULTS

Low and high doses SP significantly enhanced the proliferation ability of TDSCs. Low-dose of SP induced the expression of tenocyte-related genes; however, high-dose of SP induced the expression of non-tenocyte genes, which was evident by the high expression of PPARγ and collagen type II. In the in vivo study, only high-doses of SP (5.0 nmol) induced the tendinosis-like changes in the patella tendon injection model. Low doses of SP (0.5 nmol) enhanced the tenogenesis compared with saline injection and the high-dose SP group.

CONCLUSIONS

SP enhances the proliferation of TDSCs in vitro and the effects of SP on tendinopathy are dose-dependent in vivo.

[Partial Achilles tendon ruptures exist]

In this case report a typical case with partial Achilles tendon rupture is described. Because of unspecific symptoms, near normal MRI and no clinical signs of total rupture the diagnosis was delayed for almost four months. Open surgery showed a partial Achilles tendon rupture without significant signs of tendinopathy. The tendon was sutured and the post-operative period was uneventful.

Acetabular anteversion is associated with gluteal tendinopathy at MRI

OBJECTIVE

Gluteal tendinopathy and greater trochanteric pain syndrome (GTPS) remain incompletely understood despite their pervasiveness in clinical practice. To date, no study has analyzed the morphometric characteristics of the hip on magnetic resonance imaging (MRI) that may predispose to gluteal tendinopathy. This study aimed to evaluate whether acetabular anteversion (AA), femoral neck anteversion (FNA), and femoral neck-shaft angle (FNSA) are associated with MRI features of gluteal tendinopathy.

MATERIALS AND METHODS

A total of 203 MRI examinations of the hip met our inclusion and exclusion criteria. A single blinded investigator measured AA, FNA, and FNSA according to validated MRI techniques. Two blinded subspecialty-trained musculoskeletal radiologists then independently evaluated the presence of gluteal tendinosis, trochanteric bursitis, and subgluteal bursitis. Statistical analysis was performed using a one-way analysis of variance (ANOVA; post-hoc Tukey's range test).

RESULTS

At MRI, 57 patients had gluteal tendinosis with or without bursitis, 26 had isolated trochanteric bursitis, and 11 had isolated subgluteal bursitis. AA was significantly (p = 0.01) increased in patients with MRI evidence of gluteal tendinosis with or without bursitis [mean: 18.4°, 95 % confidence interval (CI): 17.2°-19.6°] compared with normal controls (mean: 15.7°, 95 % CI: 14.7°-16.8°). Similarly, AA was significantly (p = 0.04) increased in patients with isolated trochanteric bursitis (mean: 18.8°, 95 % CI: 16.2°-21.6°). No association was found between FNA or FNSA and the presence of gluteal tendinopathy. Interobserver agreement for the presence and categorization of gluteal tendinopathy was very good (kappa = 0.859, 95 % CI: 0.815-0.903).

CONCLUSION

Our MRI study suggests that there is an association between increased AA and gluteal tendinopathy, which supports a growing body of evidence implicating abnormal biomechanics in the development of this condition.

Therapeutic effects of high molecular weight hyaluronan injections for tendinopathy in a rat model

BACKGROUND

Tendinopathy is the most common tendon disorder. The etiology is still uncertain, and the disorder poses many therapeutic problems. In a few clinical studies, analgesic effects of high molecular weight hyaluronan (HMW HA) injections were observed, but the underlying mechanisms were not elucidated. In the present study, we analyzed the therapeutic effects of hyaluronan injections for tendinopathy in an animal model.

METHODS

We made the tendinopathy rat model using a rodent treadmill machine. Rats with tendinopathy were injected with HMW HA (HA group), normal saline (NS group), or nothing (control group) into the space between the patellar tendon and the fat pad bilaterally, or were injected with HMW HA into the right knees and with saline to the left knees (HA/NS group), 5 times every 4 days. To assess the pain-relieving effect of HA, the spontaneous locomotor activities at night (12 h) and weight bearing of hind paws were measured every day. Histological sections of the patellar tendon stained with hematoxylin-eosin or prepared by TdT-mediated dUTP nick end labeling were microscopically analyzed.

RESULTS

The number of spontaneous locomotor activities in the HA group was significantly larger than those in NS or control groups, and in the HA group they recovered up to a healthy level. The percent weight distribution of the right hind paws was significantly increased along with the number of injections. On histologic examinations, the numbers of microtears, laminations, or apoptotic cells in the patellar tendons in the HA group were significantly lower than those in the NS or the control groups.

CONCLUSIONS

The injections of HMW HA were effective for pain relief and for partial restoration of the patellar tendon in our tendinopathy rat model, and thus may become an effective therapeutic modality for the disease.

Achilles and patellar tendon morphology in dancers with and without tendon pain

OBJECTIVES

To examine Achilles and patellar tendon morphology in dancers with and without tendon pain.

METHODS

Fifty-three dancers with and without Achilles and/or patellar tendon pain participated. Eleven age-matched non-dancers served as controls. Longitudinal ultrasound images of the middle and distal Achilles and proximal and distal patellar tendons were acquired. To assess macromorphology, the thickness of the middle and distal Achilles and proximal and distal patellar tendons were measured. Micromorphology was analyzed by selecting 2 x 2-mm2 regions of interest in the tendons; spectral analysis using the fast Fourier transform was run for several kernels (2 x 2-mm2 subimages) within each image, and the peak spatial frequency (PSF) was extracted. A one-way ANOVA compared asymptomatic, symptomatic, and control tendon thickness and PSF.

RESULTS

Macromorphology: There was no significant difference between asymptomatic and symptomatic dancers in middle or distal Achilles tendon thickness and distal patellar tendon thickness. Proximal patellar tendons in control subjects were thinner than those in asymptomatic (p=0.036) and symptomatic (p=0.003) dancers. Micromorphology: There was no significant difference in PSF between asymptomatic and symptomatic dancers and controls in the Achilles or patellar tendon.

CONCLUSION

Increased proximal patellar tendon thickness without changes in tendon micromorphology suggests that tendon adaptations are more likely activity-related and less likely influenced by degeneration.

Changes in morphological and elastic properties of patellar tendon in athletes with unilateral patellar tendinopathy and their relationships with pain and functional disability

BACKGROUND

Patellar tendinopathy (PT) is one of the most common knee disorders among athletes. Changes in morphology and elasticity of the painful tendon and how these relate to the self-perceived pain and dysfunction remain unclear.

OBJECTIVES

To compare the morphology and elastic properties of patellar tendons between athlete with and without unilateral PT and to examine its association with self-perceived pain and dysfunction.

METHODS

In this cross-sectional study, 33 male athletes (20 healthy and 13 with unilateral PT) were enrolled. The morphology and elastic properties of the patellar tendon were assessed by the grey and elastography mode of supersonic shear imaging (SSI) technique while the intensity of pressure pain, self-perceived pain and dysfunction were quantified with a 10-lb force to the most painful site and the Victorian Institute of Sport Assessment-patella (VISA-P) questionnaire, respectively.

RESULTS

In athletes with unilateral PT, the painful tendons had higher shear elastic modulus (SEM) and larger tendon than the non-painful side (p<0.05) or the dominant side of the healthy athletes (p<0.05). Significant correlations were found between tendon SEM ratio (SEM of painful over non-painful tendon) and the intensity of pressure pain (rho  = 0.62; p = 0.024), VISA-P scores (rho  = -0.61; p = 0.026), and the sub-scores of the VISA-P scores on going down stairs, lunge, single leg hopping and squatting (rho ranged from -0.63 to -0.67; p<0.05).

CONCLUSIONS

Athletes with unilateral PT had stiffer and larger tendon on the painful side than the non-painful side and the dominant side of healthy athletes. No significant differences on the patellar tendon morphology and elastic properties were detected between the dominant and non-dominant knees of the healthy control. The ratio of the SEM of painful to non-painful sides was associated with pain and dysfunction among athletes with unilateral PT.

The effects of substance P on pluripotent tendon cells: an in vitro and in vivo study

Pluripotent tendon cells (PTCs) play important roles in maintaining metabolic balance and the development of tendinopathy. Recently, substance P (SP) was identified as an important factor in the pathogenesis of tendinopathy. A better understanding of SP's effects on PTCs is essential to gain more insight into tendinopathy. This study aims to investigate the effects of SP on PTCs in vitro and in vivo. For the in vitro study, we quantified exogenous SP production by PTCs and determined the effects of SP on the proliferation and differentiation of PTCs. For the in vivo study, we used a rat patella tendon injection model to investigate the biological effects of SP on PTCs and tendons. Our results showed that exogenous SP production by PTCs was 1.80 pg/10(6) cells and SP significantly enhanced the proliferation of PTCs. Reverse transcription polymerase chain reaction (RT-PCR) results showed that SP upregulated the expression of non-tenocyte genes but downregulated the expression of tenocyte-related genes in the differentiation of PTCs. Moreover, Histological examination showed that SP induced disorganizes of tissue and tendinosis-like changes in vivo. Taken together, these findings indicate that SP enhanced PTCs' proliferation, induced non-tenocyte differentiation and plays an important role in the development of tendinopathy.

Detailed shoulder MRI findings in manual wheelchair users with shoulder pain

Shoulder pain and pathology are common in manual wheelchair (MWC) users with paraplegia, and the biomechanical mechanism of injury is largely unknown. Establishing patterns of MRI characteristics in MWC users would help advance understanding of the mechanical etiology of rotator cuff disease, thus improving the logic for prescribed interventions. The purpose of this study was to report detailed shoulder MRI findings in a sample of 10 MWC users with anterolateral shoulder pain. The imaging assessments were performed using our standardized MRI Assessment of the Shoulder (MAS) guide. The tendon most commonly torn was the supraspinatus at the insertion site in the anterior portion in either the intrasubstance or articular region. Additionally, widespread tendinopathy, CA ligament thickening, subacromial bursitis, labral tears, and AC joint degenerative arthrosis and edema were common. Further reporting of detailed shoulder imaging findings is needed to confirm patterns of tears in MWC users regarding probable tendon tear zone, region, and portion. This investigation was a small sample observational study and did not yield data that can define patterns of pathology. However, synthesis of detailed findings from multiple studies could define patterns of pathological MRI findings allowing for associations of imaging findings to risk factors including specific activities.

Serum and MRI biomarkers in mobile device texting: a pilot study

OBJECTIVE

We aimed to determine if serum biochemical and MRI biomarkers differed between high volume (> or =230 texts sent/day; n = 5) and low volume (< or =25 texts sent/day; n = 5) texters. A secondary aim was to ascertain what correlations between the biochemical and imaging biomarkers could tell us about the pathophysiology of early onset tendinopathies.

BACKGROUND

Text messaging has become widespread, particularly among college-aged young adults. There is concern that high rates of texting may result in musculoskeletal disorders, including tendinopathies. Pathophysiology of tendinopathies is largely unknown.

METHOD

Ten females with a mean age of 20 were recruited. We examined serum for 20 biomarkers of inflammation, tissue degeneration, and repair. We used conventional MRI and MRI mean intratendinous signal intensity (MISI) to assess thumb tendons. Correlations between MISI and serum biomarkers were also examined.

RESULTS

Three high volume texters had MRI tendinopathy findings as did one low volume texter. Increased serum TNF-RI was found in high volume texters compared to low volume texters, as were nonsignificant increases in MISI in two thumb tendons. Serum TNF-RI and TNF-alpha correlated with MISI in these tendons, as did ILI-RI.

CONCLUSION

These results suggest that early onset tendinopathy with concurrent inflammation may be occurring in prolific texters. Further studies with larger sample sizes are needed for confirmation. Application: High volume texting may be a risk factor for thumb tendinopathy in later years. Multidisciplinary research using biochemical and imaging biomarkers may be used to gain insight into pathophysiological processes in musculoskeletal disorders.

Soft-focused extracorporeal shock waves increase the expression of tendon-specific markers and the release of anti-inflammatory cytokines in an adherent culture model of primary human tendon cells

Focused extracorporeal shock waves have been found to upregulate the expression of collagen and to initiate cell proliferation in healthy tenocytes and to positively affect the metabolism of tendons, promoting the healing process. Recently, soft-focused extracorporeal shock waves have also been found to have a significant effect on tissue regeneration. However, very few in vitro reports have dealt with the application of this type of shock wave to cells, and in particular, no previous studies have investigated the response of tendon cells to this impulse. We devised an original model to investigate the in vitro effects of soft-focused shock waves on a heterogeneous population of human resident tendon cells in adherent monolayer culture. Our results indicate that soft-focused extracorporeal shock wave treatment (0.17 mJ/mm(2)) is able to induce positive modulation of cell viability, proliferation and tendon-specific marker expression, as well as release of anti-inflammatory cytokines. This could prefigure a new rationale for routine employment of soft-focused shock waves to treat the failed healing status that distinguishes tendinopathies.

The intraoperative use of ultrasound facilitates significantly the arthroscopic debridement of calcific rotator cuff tendinitis

INTRODUCTION

During arthroscopy, the localization of calcific deposit in patients suffering from calcifying tendinitis can be demanding and time consuming, frequently using ionizing radiation. Intraoperative ultrasound has been recently promoted, facilitating deposit localization and reducing radiation dose.

MATERIAL AND METHODS

In this prospective, randomized, controlled and clinical observer-blinded pilot trial, 20 patients with calcific tendinitis were operated. In group I, the deposit was localized conventionally. In group II, the deposit was localized using intraoperative ultrasound. The needle punctures to detect the deposit and operation times were noted. Patients were postoperatively evaluated after 2 and 6 weeks and 9 months.

RESULTS

In group II, the needle punctures to detect the deposit were significantly lower than in group I (p < 0.0001). Operation time to localize the deposit was also significantly less in group II (p < 0.033). In both groups, patients improved significantly with increased shoulder function (p < 0.0001) and decreased pain (p < 0.0001) 2 weeks and 9 months (p < 0.001) after surgery. The difference between the groups was not significant. Excellent radiological findings were obtained in both groups after 9 months.

CONCLUSIONS

Intraoperative US significantly facilitates the detection of calcific deposits during arthroscopic debridement by speeding up surgery and reducing the number of needle punctures. Hence, we have changed our method of detecting calcific deposits intraoperatively from fluoroscopy to ultrasound.

An overview of structure, mechanical properties, and treatment for age-related tendinopathy

Tendons transfer tensile loads from muscle to bone, which enable joint motions and stabilize joints. Tendons sustain large mechanical loads in vivo and as a result, tendons were frequently injured. Aging has been confirmed as a predisposing factor of tendinopathy and bad recovery quality following tendon repair. Current treatment methods are generally not effective and involve either symptomatic relief with non-steroidal antiinflammatory drugs and physical therapy or surgery when conservative treatments failed. The limitation in treatment options is due to our incomplete knowledge of age-related tendinopathy. Studies over the past decades have uncovered a number of important mechanical and cellular changes of aging tendon. However, the basis of aging as a major risk factor for tendon injury and impaired tendon healing remained poorly understood. The objectives of this review are to provide an overview of the current knowledge about the aging-associated changes of structure, mechanical properties and treatment in tendon and highlight causes and therapies for age-related tendinopathy.