Substance P and calcitonin gene-related peptide expression at the extensor carpi radialis brevis muscle origin: implications for the etiology of tennis elbow

Lateral Epicondylalgia and Thoracic Kyphosis: A Study on Young Athletes

OBJECTIVE

The etiology of lateral epicondylalgia (LE) remains unclear, although it has been linked to various factors. Recent theories suggest a potential connection between LE and impairments in the kinetic chain. In our study, we aimed to investigate the association between another factor influencing kinetic chain impairment, specifically an increased angle of thoracic kyphosis, and the presence of initial signs of LE in young athletes.

DESIGN

This study employed an observational, case-control design.

SETTING

The participants underwent examination during a routine preventive checkup conducted by a sports physician at Novi Sad Healthcare Center, Sports Medicine Center.

PARTICIPANTS

One hundred young athletes aged 10 to 15 years were included in the study. Half of the participants reported pain in the lateral aspect of the elbow during maximal hand grip, while the remaining athletes served as controls and did not experience any pain.

ASSESSMENT OF INDEPENDENT VARIABLES

Thoracic kyphosis inclination angles were measured using a digital inclinometer.

MAIN OUTCOME MEASURES

Pain was assessed using the pressure pain threshold at a specific point associated with lateral epicondylalgia, measured by a digital algometer.

RESULTS

Participants exhibiting initial signs of LE displayed significantly different angles of anteroposterior curvatures of the spine compared with the control group. Moreover, the angle of thoracic kyphosis was significantly associated with pain in the lateral aspect of the elbow.

CONCLUSIONS

Our findings confirm an association between initial signs of lateral epicondylalgia and the grade of thoracic kyphosis in young athletes.

The effect of local sympatholysis on bone-tendon interface healing in a murine rotator cuff repair model

Background

Although neuroregulation plays an important role in tissue healing, the key neuroregulatory pathways and related neurotransmitters involved in bone-tendon interface (BTI) healing are still unknown. It is reported that sympathetic nerves can regulate cartilage and bone metabolism, which are the basic aspects of BTI repair after injury, through the release of norepinephrine (NE). Thus, the purpose of this study was to explore the effect of local sympatholysis (LS) on BTI healing in a murine rotator cuff repair model.

Methods

Specifically, C57BL/6 mice underwent unilateral supraspinatus tendon (SST) detachment and repair was established on a total of 174 mature C57BL/6 mice (12 weeks old): 54 mice were used to examine the sympathetic fibers and its neurotransmitter NE for the representation of sympathetic innervation of BTI, while the rest of them were randomly allocated into (LS) group and control group to verify the effect of sympathetic denervation during BTI healing. The LS group were intervened with fibrin sealant containing 10 ​ng/ml guanethidine, while the control group received fibrin sealant only. Mice were euthanized at postoperative 2, 4 and 8 weeks for immunofluorescent, qRT-PCR, ELISA, Micro-computed tomography (CT), histology and biomechanical evaluations.

Results

Immunofluorescence, qRT-PCR and ELISA evaluations indicated that there were the expression of tyrosine hydroxylase (TH), NE and β2-adrenergic receptor (β2-AR) at the BTI site. All the above showed a trend of increasing at the early postoperative stage and they started to decrease with the healing time after a significant peak. Meanwhile, local sympathetic denervation of BTI was achieved after the use of guanethidine as shown in the NE ELISA outcomes in two groups. QRT-PCR analysis revealed that the healing interface in the LS group expressed more transcription factors, such as Runx2, Bmp2, Sox9, and Aggrecan, than the control group. Further, radiographic data showed that the LS group significantly possessed higher bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and lower trabecular spacing (Tb.Sp) than the control group. Also, histological test results showed that there was more fibrocartilage regenerated at the healing interface in the LS group compared with the control group. Mechanical testing results demonstrated that the failure load, ultimate strength and stiffness in the LS group were significantly higher at postoperative week 4 (P ​< ​0.05), but not at postoperative week 8 (P ​> ​0.05), compared to the control group.

Conclusion

The regulation of sympathetic innervation was involved in the healing process of injured BTI, and local sympathetic denervation by using guanethidine was beneficial for BTI healing outcomes.The translational potential of this article: This is the first study to evaluate the expression and specific role of sympathetic innervation during BTI healing. The findings of this study also imply that the antagonists of β2-AR could serve as a potential therapeutic strategy for BTI healing. Also, we firstly successfully constructed a local sympathetic denervation mouse model by using guanethidine loaded fibrin sealant, which provided a new effective methodology for future neuroskeletal biology study.

Ultrasonography for Injecting (Around) the Lateral Epicondyle: EURO-MUSCULUS/USPRM Perspective

Lateral epicondylitis (LE) is a very common and painful condition seen in the daily practice of musculoskeletal physicians. Ultrasound-guided (USG) injections are commonly performed to manage the pain, promote the healing phase, and plan a tailored rehabilitation treatment. In this aspect, several techniques were described to target specific pain generators i the lateral elbow. Likewise, the aim of this manuscript was to extensively review those USG techniques together with the patients' pertinent clinical/sonographic features. The authors believe that this literature summary could also be refined as a practical, ready-to-use guide for planning the USG interventions of the lateral elbow in clinical practice.

Is neurogenic inflammation involved in tendinopathy? A systematic review

Neurogenic pain and inflammation have been hypothesised to play an important role in tendinopathy. This systematic review aimed to present and assess the evidence on neurogenic inflammation in tendinopathy. A systematic search was conducted through multiple databases to identify human case-control studies assessing neurogenic inflammation through the upregulation of relevant cells, receptors, markers and mediators. A newly devised tool was used for the methodological quality assessment of studies. Results were pooled based on the cell/receptor/marker/mediator assessed. A total of 31 case-control studies were eligible for inclusion. The tendinopathic tissue was obtained from Achilles (n=11), patellar (n=8), extensor carpi radialis brevis (n=4), rotator cuff (n=4), distal biceps (n=3) and gluteal (n=1) tendons. Through pooling the results of included studies based on the marker of neurogenic inflammation assessed, we identified possible upregulation of protein gene product 9.5 (PGP 9.5), N-methyl-D-aspartate Receptors, glutamate, glutamate receptors (mGLUT), neuropeptide Y (NPY) and adrenoreceptors in tendinopathic tissue versus control. Calcitonin gene-related peptide (CGRP) was not found to be upregulated, and the evidence was conflicting for several other markers. These findings show the involvement of the glutaminergic and sympathetic nervous systems and the upregulation of nerve ingrowth markers supporting the concept that neurogenic inflammation plays a role in tendinopathy.

Histologic grading correlates with inflammatory biomarkers in tibialis posterior tendon dysfunction

BACKGROUND

It has been theorized that tibialis posterior tendon dysfunction (TPTD) is a degenerative process unrelated to inflammation. The purpose of this study was to determine if inflammatory cytokines, matrix metalloproteases (MMPs), and glutamate were elevated in diseased tibialis posterior tendons (TPTs).

METHODS

Matched diseased TPT, TPT insertion, and flexor digitorum longus (FDL) samples were collected from 21 patients. The samples were individually incubated in media, which was analyzed for inflammatory cytokines, MMPs, and glutamate. Histology and statistical analyses were performed.

RESULTS

Diseased TPT and TPT insertion were significantly elevated compared to transferred FDL in eight inflammatory markers (p < 0.005). Only the diseased TPT was significantly elevated compared to the transferred FDL tendons for glutamate (p < 0.01). Histologic grading correlated with inflammatory cytokine levels.

CONCLUSION

Diseased TPT and TPT insertion demonstrated significantly elevated levels of inflammatory markers compared to the transferred tendons used as controls, suggesting a role for inflammation in the disease process. The amount of inflammation correlated with increased tendon degradation.

LEVEL OF EVIDENCE

Level III.

Effects of Heavy Slow Resistance Training Combined With Corticosteroid Injections or Tendon Needling in Patients With Lateral Elbow Tendinopathy: A 3-Arm Randomized Double-Blinded Placebo-Controlled Study

BACKGROUND

Lateral elbow tendinopathy is a disabling tendon overuse injury. It remains unknown if a corticosteroid injection (CSI) or tendon needling (TN) combined with heavy slow resistance (HSR) training is superior to HSR alone in treating lateral elbow tendinopathy.

PURPOSE/HYPOTHESIS

The purpose was to investigate the effects of HSR combined with either (1) a CSI, (2) TN, or (3) placebo needling (PN) as treatment for lateral elbow tendinopathy. We hypothesized that 12 weeks of HSR in combination with a CSI or TN would have superior effects compared with PN at 12, 26, and 52 (primary endpoint) weeks' follow-up on primary (Disabilities of the Arm, Shoulder and Hand [DASH] score) and secondary outcomes in patients with chronic unilateral lateral elbow tendinopathy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 60 patients with chronic unilateral lateral elbow tendinopathy were randomized to perform 12 weeks of home-based HSR with elastic band exercises combined with either (1) a CSI, (2) TN, or (3) PN, and at 12, 26, and 52 weeks, we assessed the primary outcome, the DASH score, and secondary outcomes: shortened version of the DASH (QuickDASH) score, pain (numerical rating scale [NRS] score), pain-free grip strength, and hypervascularization (power Doppler area).

RESULTS

A CSI, TN, and PN improved patient outcomes equally based on the DASH (Δ20 points), QuickDASH (Δ21 points), and NRS (Δ2.5 points) scores after 12 weeks. Further, after 12 weeks, a CSI also resulted in decreased hypervascularization (power Doppler area) compared with PN (Δ-2251 pixels, P = .0418). Except for the QuickDASH score (CSI increased score by Δ15 points compared with PN; P = .0427), there were no differences between the groups after 52 weeks.

CONCLUSION

These results suggest that 12 weeks of HSR improved symptoms in both the short and the long term and that a CSI or TN did not amplify this effect. In addition, a CSI seemed to impair patient-reported outcomes compared with HSR alone at long-term follow-up.

REGISTRATION

NCT02521298 (ClinicalTrials.gov identifier).

Tendinopathies and Pain Sensitisation: A Meta-Analysis with Meta-Regression

The presence of pain sensitisation has been documented and reported as being a possible cause of treatment failure and pain chronicity in several musculoskeletal conditions, such as tendinopathies. The aim of the present study is to analyse existing evidence on pain sensitisation in tendinopathies comparing the local and distant pain thresholds of healthy and affected subjects with distinct analysis for different tendinopathies. PubMed, Cochrane Central Register, Scopus, and Web Of Science were systematically searched after registration on PROSPERO (CRD42020164124). Level I to level IV studies evaluating the presence of pain sensitisation in patients with symptomatic tendinopathies, documented through a validated method, were included. A meta-analysis was performed to compare local, contralateral, and distant pain thresholds between patients and healthy controls with sub-analyses for different tendinopathies. Meta-regressions were conducted to evaluate the influence of age, activity level, and duration of symptoms on results. Thirty-four studies out of 2868 were included. The overall meta-analysis of local pressure pain thresholds (PPT) documented an increased sensitivity in affected subjects (p < 0.001). The analyses on contralateral PPTs (p < 0.001) and distant PPTs (p = 0.009) documented increased sensitivity in the affected group. The results of the sub-analyses on different tendinopathies were conflicting, except for those on lateral epicondylalgia. Patients’ activity level (p = 0.02) and age (p = 0.05) significantly influenced local PPT results. Tendinopathies are characterized by pain sensitisation, but, while features of both central and peripheral sensitisation can be constantly detected in lateral epicondylalgia, results on other tendinopathies were more conflicting. Patients’ characteristics are possible confounders that should be taken into account when addressing pain sensitisation.

Concepts of Entheseal Pain

Pain is the main symptom in entheseal diseases (enthesopathies) despite a paucity of nerve endings in the enthesis itself. Eicosanoids, cytokines, and neuropeptides released during inflammation and repeated nonphysiologic mechanical challenge not only stimulate or sensitize primary afferent neurons present in structures adjacent to the enthesis, but also trigger a "neurovascular invasion" that allows the spreading of nerves and blood vessels into the enthesis. Nociceptive pseudounipolar neurons support this process by releasing neurotransmitters from peripheral endings that induce neovascularization and peripheral pain sensitization. This process may explain the frequently observed dissociation between subjective symptoms such as pain and the structural findings on imaging in entheseal disease.

Anatomic Comparison of Recipient Nerves for Deep Inferior Epigastric Perforator Flap Neurotization: A Randomized Control Trial

INTRODUCTION

Although neurotization has the potential to improve sensory outcomes after autologous breast reconstruction, this technique remains controversial. There is debate regarding the clinical outcomes and the recipient nerve of choice. This histoanatomical study aims to quantitatively compare the sensory components of the recipient nerves involved in neurotization of the deep inferior epigastric perforator flap.

METHODS

Subjects undergoing bilateral autologous breast reconstruction were enrolled. Transected nerve specimens underwent immunohistochemical staining with antibodies against neurofilament 1 and choline acetyltransferase for total and motor neurons within the axons, respectively. Photomicrographs were captured, and axons were analyzed using ImageJ. Sensory axons were calculated as equal to the difference between the total and cholinergic axonal counts.

RESULTS

Thirty-eight nerves from 19 subjects were included. The overall mean sensory axon count was 1246.3 (±1171.9) in the lateral cutaneous branch (LCB) of the fourth intercostal nerve and 1123.8 (±1213.0) in the anterior cutaneous branch (ACB) of the third intercostal nerve.The fourth LCB presented with an additional 10.9% sensory axonal count (P > 0.05). On average, sensory fibers constituted 36.7% and 31.7% of all fibers in the third ACBs and fourth LCBs, respectively.

CONCLUSIONS

This study provides anatomic and histological evidence that the fourth LCB and third ACB contain comparable mean numbers of sensory axons. Both constitute adequate recipient nerves for coaptation in deep inferior epigastric perforator reinnervation to achieve optimal sensory return after breast reconstruction. The fourth LCB should be preferable when the third ACB remains intact to preserve any native breast flap sensation.

Lateral epicondylosis: A literature review to link pathology and tendon function to tissue-level treatment and ergonomic interventions

BACKGROUND

Common treatments for lateral epicondylosis (LE) focus on tissue healing. Ergonomic advice is suggested broadly, but recommendations based on biomechanical motion parameters associated with functional activities are rarely made. This review analyzes the role of body functions and activities in LE and integrates the findings to suggest motion parameters applicable to education and interventions relevant to activities and life roles for patients.

PURPOSE

This study examines LE pathology, tendon and muscle biomechanics, and population exposure outlining potentially hazardous activities and integrates those to provide motion parameters for ergonomic interventions to treat or prevent LE. A disease model is discussed to align treatment approaches to the stage of LE tendinopathy.

STUDY DESIGN

Integrative review METHODS: We conducted in-depth searches using PubMed, Medline, and government websites. All levels of evidence were included, and the framework for behavioral research from the National Institutes of Health was used to synthesize ergonomic research.

RESULTS

The review broadened the diagnosis of LE from a tendon ailment to one affecting the enthesis of the capitellum. It reinforced the continuum of severity to encompass degeneration as well as regeneration. Systematic reviews confirmed the availability of evidence for tissue-based treatments, but evidence of well-defined harm reducing occupational interventions was scattered amongst evidence levels. Integration of biomechanical studies and population information gave insight into types of potentially hazardous activities and provided a theoretical basis for limiting hazardous exposures to wrist extensor tendons by reducing force, compression, and shearing during functional activities.

CONCLUSIONS

These findings may broaden the first treatment approach from a passive, watchful waiting into an active exploration and reduction of at-risk activities and motions. Including the findings into education modules may provide patients with the knowledge to lastingly reduce potentially hazardous motions during their daily activities, and researchers to define parameters of ergonomic interventions.

Expression of Substance P and Nerve Growth Factor in Degenerative Long Head of Biceps Tendon in Patients with Painful Rotator Cuff Tear

Purpose

Degenerative long head of biceps tendon (LHBT) has been recognized as a notable pain source in patients with rotator cuff tear (RCT). Tenotomy or tenodesis of LHBT is frequently indicated together with arthroscopic rotator cuff repair (ARCR) aiming for complete pain relief; however, it has not been fully investigated whether resected LHBT is really a source of pain. The purpose of this study was to investigate expression levels of pain-associated mediators in LHBT and its association with preoperative pain profiles.

Methods

Twenty-seven RCT patients who underwent ARCR with LHBT resection were included. Each LHBT was resected due to its abnormal arthroscopic findings including tenosynovitis, hypertrophy, and partial tear. Worst macroscopic lesion of the LHBT was obtained, and expression levels of substance P (SP) and nerve growth factor (NGF) were evaluated using enzyme-linked immunosorbent assay (ELISA). Ten healthy knee flexor tendons were analyzed as non-degenerative samples. Preoperatively, subjective shoulder pain VAS and pain duration were investigated. Conventional LHBT pain provocation tests (Speed, Yergason, O’Brien) were performed. Pressure pain threshold (PPT) of bilateral LHBT on the groove was recorded.

Results

Levels of SP and NGF expression were significantly higher compared with non-degenerative tendons (P<0.01). Shoulder pain VAS and pain duration were not directly associated with SP and NGF expression level. Patients with positive O’Brien test expressed greater SP than negative patients (P=0.001). Significant negative correlation between the PPT ratio (ipsilateral/contralateral) and SP expression level was observed (r=−0.453, P=0.034).

Conclusion

Greater expression of SP and NGF in degenerative LHBT supported our hypothesis that it would be a pain source in RCT patients. SP was likely to be expressed highly in patients with localized pressure pain hypersensitivity and positive O’Brien test (ie, altered mechanistic pain profile of LHBT), which may help when considering simultaneous LHBT resection during ARCR.

Clinical Registration

UMIN000023943.

Increased expression of macrophages and inflammatory cytokines at tendon origin in patients with chronic lateral epicondylitis

BACKGROUND

The success of anti-inflammatory medications and corticosteroid injections in controlling chronic lateral epicondylitis symptoms suggests an underlying inflammatory pathology that is also causative of the pain experienced by patients; however, evidence regarding inflammatory mediators and cells remains inconclusive.

METHODS

We conducted a case-control study that included a total of 24 participants (10 patients and 14 controls). Extensor carpi radialis brevis tendon samples were obtained from patients, and flexor carpi radialis tendon samples were obtained from control subjects. We then performed immunohistochemical assessment to determine the expression levels of neuropeptides (substance P and calcitonin gene-related peptide), glutamate receptors (N-methyl-d-aspartate receptor type 1 and metabotropic glutamate receptor 5), inflammatory cytokines (interleukin 1α and tumor necrosis factor α), and inflammatory cells (M1 macrophages [CD68], M2 macrophages [CD163 and CD206], T-lymphocytes [CD3], and B-lymphocytes [CD20]).

RESULTS

Patients' sampled extensor carpi radialis brevis tendons showed significantly elevated expression levels of neuropeptides, glutamate receptors, and inflammatory cytokines, along with a number of macrophages, compared with controls (P < .001 or P < .0001); however, there were no differences in the number of T- and B-lymphocytes between the 2 groups.

CONCLUSION

The findings of this study showed that inflammation is involved in the pathology of chronic lateral epicondylitis.

The expression of substance P and calcitonin gene-related peptide is associated with the severity of tendon degeneration in lateral epicondylitis

BACKGROUND

In this study, we investigated whether substance P (SP) or calcitonin gene-related peptide (CGRP) expression is associated with tendon degeneration in patients with lateral epicondylitis.

METHODS

Twenty-nine patients who underwent surgical treatment for lateral epicondylitis were enrolled in the final analyses. Extensor carpi radialis brevis tendon origins were harvested for histological analysis.

RESULTS

SP and CGRP immunostaining were negative in healthy tendons but positive in degenerative tendons; moreover, their immunoreactivity increased with degeneration severity. Univariate analysis indicated that variables such as the preoperative visual analog scale (VAS) score or SP or CGRP expression levels were significantly associated with the Movin score. However, multivariate analysis revealed that only higher SP and/or CGRP signals were associated with higher Movin scores. Elevations in SP or CGRP expression were also linked with significantly severe preoperative VAS scores.

CONCLUSION

We demonstrated that tendon degeneration severity is associated with increased SP and CGRP expression in the biopsy samples of lateral epicondylitis.

Strategy for the treatment of lateral epicondylitis of the elbow using denervation surgery

Background

A number of treatments for lateral epicondylitis of the elbow have been described. We have developed a strategy for the treatment of this condition.

Methods

We diagnosed lateral epicondylitis of the elbow in 86 patients. Conservative treatment resulted in resolution in 71 patients. Surgery was required in the remaining 15 patients. If the posterior branch of the posterior cutaneous nerve of the forearm showed a positive response to local anesthesia (block test), we performed denervation surgery on the posterior branch of the posterior cutaneous nerve of the forearm. Patients were asked to rate the degree of pain and sensory disturbance using a visual analog scale; the 11-item version of the Disabilities of the Arm, Shoulder and Hand measure; and the Patient-Rated Elbow Evaluation.

Results

A positive response to the block test was seen in 10 elbows (67%). After denervation surgery, pain relief was seen in 9 of 10 elbows (90%). The mean follow-up period was 30.4 months. At final follow-up, the average scores on the visual analog scale, 11-item version of the Disabilities of the Arm, Shoulder and Hand, and Patient-Rated Elbow Evaluation were 4.3 mm, 10.45 points, and 5.9 points, respectively. In the early period after denervation surgery, sensory disturbance was observed in 9 cases (90%).

Conclusion

Our strategy of denervation surgery for lateral epicondylitis of the elbow was effective for pain relief among patients showing a positive response to the block test.

A systematic review of inflammatory cells and markers in human tendinopathy

BACKGROUND

This article systematically reviews the current evidence regarding inflammation in Tendinopathy with the aim to increase understanding of a potential common pathophysiology.

METHODS

Following the PRISMA statements, the terms: (tendinopathy OR (tendons AND rupture)) AND (inflammation OR (inflammation AND cells) OR immune system OR inflammation mediators OR bacteria) were used. One thousand four hundred thirty-one articles were identified which was screened down to 53.

RESULTS

39/53 studies mentioned inflammatory cells but had contradicting conclusions. Macrophages were the most common cell type and inflammatory markers were detectable in all the articles which measure them.

CONCLUSIONS

The included studies show different conclusions, but this heterogeneity is not unexpected since the clinical criteria of 'tendinopathy' encompass a huge clinical spectrum. Different 'tendinopathy' conditions may have different pathophysiology, and even the same clinical condition may be at different disease stages during sampling, which can alter the histological and biochemical picture. Control specimen sampling was suboptimal since the healthy areas of the pathological-tendon may actually be sub-clinically diseased, as could the contralateral tendon in the same subject. Detection of inflammatory cells is most sensitive using immunohistochemistry targeting the cluster of differentiation markers, especially when compared to the conventional haematoxylin and eosin staining methods. The identified inflammatory cell types favour a chronic inflammatory process; which suggests a persistent stimulus. This means NSAID and glucocorticoids may be useful since they suppress inflammation, but it is noted that they may hinder tendon healing and cause long term problems. This systematic review demonstrates a diversity of data and conclusions in regard to inflammation as part of the pathogenesis of Tendinopathy, ranging from ongoing or chronic inflammation to non-inflammatory degeneration and chronic infection. Whilst various inflammatory markers are present in two thirds of the reviewed articles, the heterogenicity of data and lack of comparable studies means we cannot conclude a common pathophysiology from this systematic review.

A single-pulsed electromagnetic field enhances collagen synthesis in tendon cells

Tendinopathy is a progressive pathology of tendon that is characteristic of imbalance between matrix synthesis and degeneration and is often caused by failure to adapt to mechanical loading. Non-steroidal anti-inflammatory medications (NSAIDS) are used as a conventional treatment to alleviate pain and swelling in the short term, but the ideal treatment for tendinopathy remains unclear. Here, we show a single pulsed electromagnetic field (SPEMF, 0.2 Hz) that up-regulated tenogenic gene expression (Col1a1, Col3a1, Scx, Dcn) and down-regulated inflammatory gene expression (Mmp1) in vitro. After five days of SPEMF stimulation (3 min/day), the collagen type I and total collagen synthesis protein levels were significantly increased. Under pro-inflammatory cytokine (IL-1β) irritation, the decreased expression of Col1a1/Col3a1 was up-regulated by SPEMF treatment, and the increased expression of Mmp1 was also reversed. From the above, it can be inferred that SPEMF that enhances matrix synthesis and reduces matrix degeneration may counteract the imbalance in tendinopathy. SPEMF application may be developed as a potential future strategy for therapeutic intervention in tendon disorders.

Structural and molecular characteristics of axons in the long head of the biceps tendon

The innervation of the long head of the biceps tendon (LHBT) is not sufficiently documented. This is a drawback since pathologies of the LHBT are a major source of shoulder pain. Thus, the study aimed to characterize structurally and molecularly nervous elements of the LHBT. The proximal part of 11 LHBTs was harvested intraoperatively. There were 8 female and 3 male specimens. Age ranged from 66 to 86 years. For structural analyses, nervous elements were viewed in the transmission electron microscope. For molecular characterization, we used general neuronal markers including antibodies against neurofilament and protein gene product 9.5 (PGP9.5) as well as specific neuronal markers including antibodies against myelin basic protein (MBP), calcitonin gene-related product (CGRP), substance P (SP), tyrosine hydroxylase (TH), and growth-associated protein 43 (GAP43). Anti-neurofilament and anti-PGP9.5 visualized the overall innervation. Anti-MBP visualized myelination, anti-CGRP and anti-SP nociceptive fibers, anti-TH sympathetic nerve fibers, and anti-GAP43 nerve fibers during development and regeneration. Immunolabeled sections were analyzed in the confocal laser scanning microscope. We show that the LHBT contains unmyelinated as well as myelinated nerve fibers which group in nerve fascicles and follow blood vessels. Manny myelinated and unmyelinated axons exhibit molecular features of nociceptive nerve fibers. Another subpopulation of unmyelinated axons exhibits molecular characteristics of sympathetic nerve fibers. Unmyelinated sympathetic fibers and unmyelinated nociceptive fibers express proteins that are found during development and regeneration. Present findings support the hypothesis that ingrowth of nociceptive fibers are the source of chronic tendon pain.

Molecular Pattern and Density of Axons in the Long Head of the Biceps Tendon and the Superior Labrum

The type II superior labrum anterior to posterior (SLAP) repair is a viable option in young and demanding patients, although a prolonged period of pain after surgery is described in the literature. The reason for this fact remains unknown. Thus, the purpose of this study was to investigate the molecular pattern of the biceps tendon anchor, where the sutures for repair are placed. The long head of the biceps tendon (LHBT), including the superior labrum, was dissected in the setting of reverse total shoulder arthroplasty. Immunohistochemical staining was performed using neurofilament (NF) and protein gene product (PGP) 9.5 as general markers for axons and calcitonin gene-related peptide (CGRP) and substance P for nociceptive transmission. A quantitative assessment was performed according to the two regions of interest (ROIs), i.e., the anterosuperior (ROI I) and the posterosuperior labrum (ROI II). Eleven LHBTs with a mean age of 73 years (range: 66–87 years) were harvested intraoperatively. Six LHBTs were gained in osteoarthrosis and five in fractures. We found an inhomogeneous distribution of axons in the anterosuperior and posterosuperior parts of the labrum in all the specimens irrespective of the age, gender, and baseline situation. There was a significantly higher number (p < 0.01) as well as density (p < 0.001) of NF-positive axons in ROI I compared to ROI II. Nociceptive fibers were always found along the NF-positive axons. Thus, our results indicate that the biceps tendon anchor itself is a highly innervated region comprising different nerve qualities. The anterosuperior labrum contains a higher absolute number and density of axons compared to the posterosuperior parts. Furthermore, we were able to prove the presence of nociceptive fibers in the superior labrum. The results obtained in this study could contribute to the variability of pain after SLAP repair.

Ultrasound-Guided Percutaneous Electrical Nerve Stimulation of the Radial Nerve for a Patient With Lateral Elbow Pain: A Case Report With a 2-Year Follow-up

BACKGROUND

Patients with lateral elbow pain are often diagnosed with lateral epicondylalgia. Lateral elbow pain is often associated with dysfunction of the wrist extensor muscles; however, in some cases, it can also mimic signs and symptoms of radial nerve dysfunction.

CASE DESCRIPTION

In this case report, a 43-year-old man, who was originally referred with a diagnosis of lateral epicondylalgia as a result of playing table tennis and who previously responded favorably to manual therapy and exercise, presented to the clinic for treatment. An exacerbation while participating in a table tennis match resulted in a return of his lateral epicondylalgia symptoms, which did not respond favorably to the same interventions used in his prior course of therapy. Further examination revealed sensitization of the radial nerve, which was treated with 2 sessions of ultrasound-guided percutaneous electrical nerve stimulation and 4 weeks of a low-load, concentric/eccentric exercise program for the wrist extensors.

OUTCOMES

Following this intervention, the patient experienced clinically meaningful improvement in pain intensity (numeric pain-rating scale), function (Patient-Rated Tennis Elbow Evaluation), and related disability (Disabilities of the Arm, Shoulder and Hand questionnaire). The patient progressively exhibited complete resolution of pain and function, which was maintained at 2 years.

DISCUSSION

This case report demonstrates the outcomes of a patient with lateral elbow pain who did not respond to manual therapy and exercise. Once radial nerve trunk sensitivity was identified and the intervention, consisting of ultrasound-guided percutaneous electrical nerve stimulation targeting the radial nerve combined with a low-load exercise program, was applied, a full resolution of pain and function occurred rapidly. Future clinical trials should examine the effect of percutaneous electrical nerve stimulation in the management of nerve-related symptoms associated with musculoskeletal pain conditions.

LEVEL OF EVIDENCE

Therapy, level 5. J Orthop Sports Phys Ther 2019;49(5):347-354. Epub 18 Jan 2019. doi:10.2519/jospt.2019.8570.

Short-Term Effect of Low-Dose, Electromyography-Guided Botulinum Toxin A Injection in the Treatment of Chronic Lateral Epicondylar Tendinopathy: A Randomized, Double-Blinded Study

BACKGROUND

Botulinum toxin A (BoNT-A) is a novel treatment for chronic lateral epicondylar tendinopathy. Preliminary studies have demonstrated promising results; however, confirmation of the effectiveness of BoNT-A treatment and further assessment of its side effects are required. This study investigated the analgesic effects of BoNT-A in the treatment of chronic lateral epicondylar tendinopathy.

METHODS

This was a phase-III, single-center, randomized, double-blinded, placebo-controlled study including 60 patients with chronic lateral epicondylar tendinopathy that had been resistant to treatment for >6 months. Patients received either a 40-IU injection of BoNT-A or saline solution placebo into the extensor carpi radialis brevis (ECRB) muscle, aided by electromyographic (EMG) stimulation. Follow-up was 3 months. The primary assessment criterion was the percentage of patients whose pain was reduced by >50% at 90 days after injection. Secondary outcomes, including pain intensity, pain frequency, interference with quality of life, sick leave taken, maximum grip strength, and side effects, were assessed at days 30 and 90, and the number of participants per group requesting additional therapies at day 90 was recorded.

RESULTS

Twenty-nine patients in the BoNT-A group and 28 patients in the placebo group were included in the day-90 analysis. Fifteen (51.7%) of the patients who were administered BoNT-A and 7 (25%) of the patients who received placebo reported a >50% reduction in initial pain intensity at day 90 (p = 0.005). Pain intensity and the effect on quality of life, measured using visual analog scales, were both significantly lower in the group treated with BoNT-A compared with placebo at day 90 (p < 0.05). The rate of clinically detected transitory paresis of the third finger on extension was 17.2% in the BoNT-A group, with no associated functional impairment.

CONCLUSIONS

BoNT-A at 40 IU injected into the ECRB is an effective treatment for chronic lateral epicondylar tendinopathy that has been otherwise resistant to medical treatment. The rate of paresis of the third finger was low, with no associated functional impairment.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Transcatheter arterial embolization of abnormal vessels as a treatment for lateral epicondylitis refractory to conservative treatment: a pilot study with a 2-year follow-up

BACKGROUND

Abnormal vessels and accompanying nerves are possible sources of pain with lateral epicondylitis. The purpose of this study was to describe the safety and efficacy of transcatheter arterial embolization (TAE) for lateral epicondylitis resistant to conservative treatment.

METHODS

This prospective study was conducted in 24 patients with lateral epicondylitis resistant to conservative treatments for more than 3 months, with a symptom duration longer than 6 months, and with moderate to severe pain who were treated with TAE between March 2013 and October 2014. Two patients were lost to follow-up, and the remaining 22 patients were followed up for 2 years after TAE.

RESULTS

Abnormal vessels were identified in all of the patients. No major adverse events were observed. The Quick Disabilities of the Arm, Shoulder and Hand scores at baseline significantly decreased at 1, 3, 6, and 24 months after treatment (50.8 vs 23.4, 8.3, 5.3, and 2.7, respectively; all P < .001). There was a statistically significant (P < .001) change from baseline to the last observed value in all of the clinical parameters, including visual analog scale pain score, Patient-Rated Tennis Elbow Evaluation score, and pain-free grip strength. Magnetic resonance images obtained 2 years after TAE showed an improvement in tendinosis and tear scores compared with baseline, and no patients showed bone marrow necrosis, obvious cartilage loss, or muscle atrophy.

CONCLUSION

TAE could be one possible treatment option for patients with lateral epicondylitis that fails to improve with conservative treatments.

Chronic pain alters spatiotemporal activation patterns of forearm muscle synergies during the development of grip force

It is largely unknown how the CNS regulates multiple muscle systems in the presence of pain. This study used muscle synergy analysis to investigate multiple forearm muscles in individuals with chronic elbow pain during the development of grip force. Eleven individuals with chronic elbow pain and 11 healthy age-matched control subjects developed grip force to 15% and 30% of maximum voluntary contraction (MVC). Surface electromyography was obtained from six forearm muscles during force development before nonnegative matrix factorization was performed. The relationship between muscle synergies and standard clinical tests of elbow pain were examined by linear regression. During grip force development to 15% MVC the pain group had a lower number of forearm muscle synergies, increased similarity in spatial activation patterns, increased cocontraction of forearm flexors, and a greater magnitude of muscle weightings across the forearm when performing the task. During the 30% MVC grip the numbers of muscle synergies were the same for both groups; however, the pain group had lower activation and reduced variability in the timing of peak activation. The timing of peak activation was delayed in the pain group regardless of the task, and performing the grip in different wrist postures did not affect muscle synergy characteristics in either group. Although localized pain causes direct dysfunction of an affected muscle, this study provides evidence that the timing and amplitude of agonist and antagonist muscle activity are also affected with chronic pain.NEW & NOTEWORTHY Muscle activation patterns of individuals with chronic elbow pain are simplified compared with healthy individuals. This is apparent as individuals with pain exhibit fewer forearm muscle synergies, and increased similarity of activation patterns between forearm muscles, when performing pain-free isometric gripping. As such, even during pain-free tasks it is possible to observe changes in motor control in people with chronic pain.

Decreased Brain Neurokinin-1 Receptor Availability in Chronic Tennis Elbow

Substance P is released in painful and inflammatory conditions, affecting both peripheral processes and the central nervous system neurokinin 1 (NK1) receptor. There is a paucity of data on human brain alterations in NK1 expression, how this system may be affected by treatment, and interactions between central and peripheral tissue alterations. Ten subjects with chronic tennis elbow (lateral epicondylosis) were selected out of a larger (n = 120) randomized controlled trial evaluating graded exercise as a treatment for chronic tennis elbow (lateral epicondylosis). These ten subjects were examined by positron emission tomography (PET) with the NK1-specific radioligand 11C-GR205171 before, and eight patients were followed up after treatment with graded exercise. Brain binding in the ten patients before treatment, reflecting NK1-receptor availability (NK1-RA), was compared to that of 18 healthy subjects and, longitudinally, to the eight of the original ten patients that agreed to a second PET examination after treatment. Before treatment, patients had significantly lower NK1-RA in the insula, vmPFC, postcentral gyrus, anterior cingulate, caudate, putamen, amygdala and the midbrain but not the thalamus and cerebellum, with the largest difference in the insula contralateral to the injured elbow. No significant correlations between brain NK1-RA and pain, functional severity, or peripheral NK1-RA in the affected limb were observed. In the eight patients examined after treatment, pain ratings decreased in everyone, but there were no significant changes in NK1-RA. These findings indicate a role for the substance P (SP) / NK1 receptor system in musculoskeletal pain and tissue healing. As neither clinical parameters nor successful treatment response was reflected in brain NK1-RA after treatment, this may reflect the diverse function of the SP/NK1 system in CNS and peripheral tissue, or a change too small or slow to capture over the three-month treatment.

Injection of autologous blood versus corticosteroid for lateral epicondylitis: a randomised controlled study

PURPOSE

To compare the efficacy of autologous blood injection versus corticosteroid injection for lateral epicondylitis.

METHODS

21 men and 59 women (mean age, 45.2 years) presenting with lateral epicondylitis were randomised to receive either autologous blood injection (2 ml of autologous venous blood mixed with 1 ml of 2% prilocaine hydrochloride) or corticosteroid injection (1 ml of 40 mg methylprednisolone acetate mixed with 1 ml of 2% prilocaine hydrochloride) given by a single physician. Patients were assessed before (day 0) and after (days 15, 30, and 90) treatment for elbow pain (using a visual analogue scale [VAS]), function (using the patient-rated tennis elbow evaluation [PRTEE] questionnaire), and grip strength (using a hydraulic hand dynamometer). Patients were followed up at 6 months by telephone to assess elbow pain using the VAS.

RESULTS

No complications (infection, skin atrophy, neurovascular damage, or tendon rupture) were noted. 10 patients reported increased pain for up to 2 days after autologous blood injection. In both groups, the VAS score for elbow pain, PRTEE score, and grip strength improved significantly after treatment (p=0.0001), but the pattern of improvement differed. Compared with autologous blood injection, corticosteroid injection improved all 3 scores at a faster rate over the first 15 days (p=0.0001), and then started to decline slightly until day 90. After autologous blood injection, all 3 scores improved steadily and were eventually better (p=0.0001). If a 37% decrease in PRTEE is defined as complete recovery, 38 (95%) of patients with autologous blood injection and 25 (62.5%) of patients with corticosteroid injection achieved complete recovery (p=0.0001).

CONCLUSION

Autologous blood injection was more effective over the follow-up period than corticosteroid injection in improving pain, function, and grip strength. It is recommended as a first-line injection treatment because it is simple, cheap, and effective.

PET-scan shows peripherally increased neurokinin 1 receptor availability in chronic tennis elbow: visualizing neurogenic inflammation?

In response to pain, neurokinin 1 (NK1) receptor availability is altered in the central nervous system. The NK1 receptor and its primary agonist, substance P, also play a crucial role in peripheral tissue in response to pain, as part of neurogenic inflammation. However, little is known about alterations in NK1 receptor availability in peripheral tissue in chronic pain conditions and very few studies have been performed on human beings. Ten subjects with chronic tennis elbow were therefore examined by positron emission tomography (PET) with the NK1 specific radioligand [(11)C]GR205171 before and after treatment with graded exercise. The radioligand signal intensity was higher in the affected arm as compared with the unaffected arm, measured as differences between the arms in volume of voxels and signal intensity of this volume above a reference threshold set as 2.5 SD above mean signal intensity of the unaffected arm before treatment. In the eight subjects examined after treatment, pain ratings decreased in all subjects but signal intensity decreased in five and increased in three. In conclusion, NK1 receptors may be activated, or up-regulated in the peripheral, painful tissue of a chronic pain condition. This up-regulation does, however, have moderate correlation to pain ratings. The increased NK1 receptor availability is interpreted as part of ongoing neurogenic inflammation and may have correlation to the pathogenesis of chronic tennis elbow.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00888225 http://clinicaltrials.gov/

Innervation pattern at the undersurface of the extensor carpi radialis brevis tendon in recalcitrant tennis elbow

PURPOSE

We investigated the general, sensory, and sympathetic innervation patterns at the undersurface of the extensor carpi radialis brevis (ECRB) origin in patients with recalcitrant tennis elbow.

METHODS

Eight elbows in eight consecutive patients (6 females and 2 males) with tennis elbow who underwent arthroscopic surgery were included in this study. The mean age was 45 years (38-66 years), and the mean duration of symptoms before surgery was 23 months (13-52 months). Operative treatment consisted of an arthroscopic inspection and debridement of the ECRB origin. Control tissues were obtained from biopsy of the ECRB capsule in two patients with osteochondritis dissecance of the capitellum who underwent arthroscopic resection of loose bodies. The tissue specimens were investigated immunohistochemically with antibodies delineating general (PGP9.5), sensory (SP/CGRP), and sympathetic (NPY) nerve patterns.

RESULTS

In the non-tendinosis control tissue, SP/CGRP and NPY immunoreactions were heterogeneously distributed in association with blood vessels. Pathologic evaluation of the biopsy tissue showed atypical fibrous granulation containing numerous vessels and nerve structures in all eight patients. Marked reactions to PGP 9.5 took the form of nerve fibers associated with arteries and arterioles in the atypical granulation. Most of the perivascular innervation was found to express NPY. The immunoreactions for SP and CGRP were invariably weak.

CONCLUSION

Increased perivascular sympathetic innervation accompanied with loss of sensory innervation at the undersurface of the ECRB tendon may play a role in chronic pain generation in recalcitrant tennis elbow.

LEVEL OF EVIDENCE

Diagnostic, Level IV.

The effects of corticosteroid injection versus local anesthetic injection in the treatment of lateral epicondylitis: a randomized single-blinded clinical trial

INTRODUCTION

This study seeks to compare two treatment methods of lateral epicondylitis: corticosteroid injection (CSI) and a local anesthetic injection (LAI).

MATERIALS AND METHODS

In this single-blinded randomized clinical trial, 138 patients with the diagnosis of lateral epicondylitis were assigned either into CSI group receiving methylprednisolone 1 ml (49 patients) or LAI group (51 patients) receiving procaine 1 ml 2 % in a single dose at the maximal point tenderness site. The primary outcome measure was elbow disability using Quick DASH, and secondary outcome measures were pain intensity using Visual Analogue Scale (VAS) and recurrence rate at pretreatment visit and at 3-, 6- and 12-week post-treatment visits.

RESULTS

There were no significant differences between the patients in both groups for demographic factors including age, gender, dominant hand, involved hand, and work pressure. Before treatment, the patients in both groups were suffering from the same rates of elbow disability and pain as measured by Quick DASH and VAS, respectively, (p > 0.05). In general, the recovery rate (comparison between pretreatment visit and last post-treatment visit) was significantly more effective and higher in CSI than LAI. CSI was dramatically more effective at 3-week visit, but less and less effective at 6- and 12-week visits. At 12-week visit the recurrence rate was 34.7 % (17 patients) in CSI group.

CONCLUSION

For lateral epicondylitis, CSI has the best short-term treatment results yet the highest recurrent rates. The combination of CSI with other treatment option or with a change in injection technique from single injection to peppering injection may be promising.

Risk factors in lateral epicondylitis (tennis elbow): a case-control study

Lateral epicondylitis is a common condition, but relatively little is known about its aetiology and associated risk factors. We have undertaken a large case-control study using The Health Improvement Network database to assess and quantify the relative contributions of some constitutional and environmental risk factors for lateral epicondylitis in the community. Our dataset included 4998 patients with lateral epicondylitis who were individually matched with a single control by age, sex, and general practice. The median age at diagnosis was 49 (interquartile range 42-56) years . Multivariate analysis showed that the risk factors associated with lateral epicondylitis were rotator cuff pathology (OR 4.95), De Quervain's disease (OR 2.48), carpal tunnel syndrome (OR 1.50), oral corticosteroid therapy (OR 1.68), and previous smoking history (OR 1.20). Diabetes mellitus, current smoking, trigger finger, rheumatoid arthritis, alcohol intake, and obesity were not found to be associated with lateral epicondylitis.

Clinical presentation and manual therapy for upper quadrant musculoskeletal conditions

In recent years, increased knowledge of the pathogenesis of upper quadrant pain syndromes has translated to better management strategies. Recent studies have demonstrated evidence of peripheral and central sensitization mechanisms in different local pain syndromes of the upper quadrant such as idiopathic neck pain, lateral epicondylalgia, whiplash-associated disorders, shoulder impingement, and carpal tunnel syndrome. Therefore, a treatment-based classification approach where subjects receive matched interventions has been developed and, it has been found that these patients experience better outcomes than those receiving non-matched interventions. There is evidence suggesting that the cervical and thoracic spine is involved in upper quadrant pain. Spinal manipulation has been found to be effective for patients with elbow pain, neck pain, or cervicobrachial pain. Additionally, it is known that spinal manipulative therapy exerts neurophysiological effects that can activate pain modulation mechanisms. This paper exposes some manual therapies for upper quadrant pain syndromes, based on a nociceptive pain rationale for modulating central nervous system including trigger point therapy, dry needling, mobilization or manipulation, and cognitive pain approaches.

Tendinopathies of the elbow, wrist, and hand: histopathology and clinical considerations

This article reviews the current opinion of the histopathological findings of common elbow, wrist, and hand tendinopathies. Implications for client management including examination, diagnosis, prognosis, intervention, and outcomes are addressed. Concepts for further research regarding common therapeutic interventions are discussed.

Anatomical association between wrist extensor musculature and topographical pain sensitivity maps of the elbow area

OBJECTIVE

High-density topographical sensitivity maps have been developed to visualize nonuniformity deep tissue pain sensitivity in, for example, lateral epicondylitis (LE). The aim of this cadaveric study was to determine the anatomical association between the topographical sensitivity maps over the elbow area and wrist extensor musculature.

METHODS

A topographical pressure sensitivity map consisting of 12 points forming a 3 × 4 matrix: 4 points in the superior part, 4 points in the middle, and 4 points in the lower part around the lateral epicondyle was marker on a 50-year embalmed cadaver. Color marker pins were inserted into each point. Pins were removed during the process of dissection, but the small holes created by their removal assured accurate relocation.

RESULTS

Progressive dissection revealed that points 1 to 4 (superior line) were placed over the musculotendinous junction and belly of the extensor carpi radialis brevis (ECRB) muscle, points 6 to 8 (middle line) were placed over the musculotendinous junction and belly of the extensor digitorum communis muscle, and points 9 to 12 (inferior line) were located over the musculotendinous junction and belly of the extensor carpi ulnaris muscle. It was also observed that the superficial branch of the radial nerve runs between the belly of the ECRB and extensor digitorum communis muscles.

CONCLUSIONS

This study confirmed that anatomical location previously assumed supporting the important wrist extensor muscles, particularly the ECRB, in patients with LE as depicted by pressure pain sensitivity maps. This study also suggests a potential role of the superficial branch of the radial nerve in LE.

Asymptomatic Achilles, patellar, and quadriceps tendinopathy: a longitudinal clinical and ultrasonographic study in elite fencers

Lower limb tendon changes detected at imaging are common among asymptomatic athletes. We aimed to prospectively assess the clinical status, tendon structure, and vascularity of lower limb tendons of elite fencers, and predict the risk of developing symptoms over time. Clinical examination, changes at ultrasonography (US), and Power Doppler (PD) flow of both the Achilles, patellar, and quadriceps tendon were assessed in 37 elite fencers in January 2007 and 3 years after. Two hundred and twenty-two tendons were examined. At the last appointment, patellar tendons diagnosed as abnormal at baseline were more likely to develop symptoms than those normal at baseline (P < 0.05, Fisher's exact test), while US and PD abnormalities on Achilles and quadriceps tendons were no predictive for development of symptoms over years. A very low percentage of tendons diagnosed as normal at baseline (1.45%) showed US abnormalities at 3-year follow-up. In asymptomatic elite fencers, structural changes are relatively common at US and PD assessment of Achilles, quadriceps, and patellar tendons. It seems unlikely that additional PD investigations provide further information or change prognosis in patients with US diagnosis of tendinopathy.

Joint manipulation in the management of lateral epicondylalgia: a clinical commentary

Lateral epicondylalgia or tennis elbow is a prevalent musculoskeletal disorder that is characterized by lateral elbow pain often associated with gripping tasks. The underlying pathology remains to be fully elucidated; however, evidence indicates that the disorder does not involve an inflammatory process but rather impairments of the pain and motor systems as well as morphological changes in the structure of both the extensor carpi radialis brevis muscle and tendon. Although the most efficient management approach remains controversial, there is a growing body of literature reporting the effects and underlying mechanisms of joint manipulation in the management of lateral epicondylalgia. Evidence exists demonstrating that joint manipulation directed at the elbow and wrist as well as at the cervical and thoracic spinal regions results in clinical alterations in pain and the motor system. In addition to presenting this evidence, this paper describes proposed underlying physiological mechanisms of joint manipulation associated with the observed clinical effects. We propose that this information will be useful for the physical therapist in making clinical decisions regarding the selection of treatment technique for the management of patients with lateral epicondylalgia.

Interactive effects of acute experimental pain in trapezius and sored wrist extensor on the electromyography of the forearm muscles during computer work

We investigated the interactive effects of shoulder pain and wrist extensor muscle soreness on surface electromyography (EMG) during computer mouse work. On day one, subjects (N = 12) performed computer work with/without acute muscle pain induced in the trapezius muscle. Subsequently, eccentric exercise was performed to induce delayed onset muscle soreness (DOMS) in wrist extensor muscles. In presence of DOMS on day two, computer work recordings with/without pain were repeated. EMG signals were recorded from the descending part of trapezius bilaterally, flexor carpi ulnaris and extensor carpi radialis brevis. Experimental muscle pain in trapezius led to a decrease in the muscular activity of the wrist extensor (P < 0.02) and decreased the relative rest time in the wrist flexor even in presence of DOMS (P < 0.01). The present result suggests that shoulder pain plays a role in the coordination of wrist flexors and extensors during computer work.

Novel use of a manual therapy technique and management of a patient with peroneal tendinopathy: a case report

Peroneal tendinopathy is an uncommon but underappreciated source of lateral hindfoot pain and dysfunction. There is a paucity of literature describing optimal intervention for those suffering with pain secondary to peroneal tendinopathy. The purpose of this case report is to describe the evaluation and treatment incorporating manual therapy and therapeutic exercise for a patient diagnosed with peroneal tendinopathy. The patient was a 50 year-old female with a history of chronic lateral ankle pain and whose presentation was consistent with peroneal tendinopathy. Despite attempts to improve pain and function with over-the-counter orthotics, manual therapy to a hypomobile talocrural joint, and strengthening of the peroneal tendons, successful response was not reported until a lateral calcaneal glide was added. Improvement in impairments (pain, talocrural dorsiflexion, unilateral heel raises, and Star Excursion Balance Test) and function (Lower Extremity Functional Scale and Global Rating of Change), were observed over a course of eight visits. The patient was able to return to work and her recreational work out routine without limitations. In conclusion a successful physical therapy intervention for a patient with peroneal tendinopathy included a unique manual therapy technique, the lateral calcaneal glide, in conjunction with other manual therapy techniques and a structured home exercise program.

Extensor tendon release in tennis elbow: results and prognostic factors in 80 elbows

PURPOSE

The objectives of this study were to evaluate the results in the outpatient treatment of recalcitrant lateral epicondylitis with release of the common extensor origin according to Hohmann and to determine any prognostic factors.

METHODS

Eighty tennis elbows in 77 patients with a characteristic history of activity-related pain at the lateral epicondyle interfering with the activities of daily living refractory to conservative care for at least 6 months and a confirmatory physical examination were included. Clinical outcome was evaluated using the QuickDASH score system. Data were collected before the operation and at the medians of 18 months (range 6-36 months; short term) and 4 years (range 3-6 years; medium term) postoperatively.

RESULTS

The mean QuickDASH was improved both at the short- and the medium-term follow-ups and did not change significantly between the follow-ups. At the final follow-up, the QuickDASH was improved in 78 out of 80 elbows and 81% was rated as excellent or good (QuickDASH<40 points). We found a weak correlation between residual symptoms (a high QuickDASH score) at the final follow-up and high level of baseline symptoms (r=0.388), acute occurrence of symptoms (r=0.362), long duration of symptoms (r=0.276), female gender (r=0.269) and young age (r=0.203), whereas occurrence in dominant arm, a work-related cause or strenuous work did not correlate significantly with the outcome.

CONCLUSION

Open lateral extensor release performed as outpatient surgery results in improved clinical outcome at both short- and medium-term follow-ups with few complications. High baseline disability, sudden occurrence of symptoms, long duration of symptoms, female gender and young age were found to be weak predictors of poor outcome.

LEVEL OF EVIDENCE

Case series, Level IV.

Cell therapy in tendon disorders: what is the current evidence?

BACKGROUND

Various types of tissue-derived cells are being experimented with for the treatment of tendinopathy, tendon repair, and use in tissue engineering.

PURPOSE

The aim of this systematic review is to explore the current evidence with a view to evaluate the potential of this therapeutic intervention.

STUDY DESIGN

Systematic review.

METHODS

A review of the literature was conducted using PubMed. Search criteria included keywords "tendinopathy," "tendinitis," "tendinosis," "epicondylitis," "stem cell," and "cell therapy." Articles not written in English language were excluded.

RESULTS

A total number of 379 articles were identified and a critical appraisal of the relevant articles was undertaken, which encompassed human and animal research. The review included articles related to various tissue-derived cells such as tendon progenitors, adipose tissue, synovium, muscle, bone marrow, and skin. The utility of cell therapy in tissue engineering and rotator cuff repair was also assessed.

CONCLUSION

With the limitation of the available evidence, the literature suggests that cell therapy is applicable and may be effective for the treatment of tendinopathy. However, further research into the precise biological mechanisms, long-term implications, and cost-effectiveness is needed.

Treatment of scapula dyskinesia with botulin toxin: two case reports

We report two cases of scapula-thoracic dyskinesia with different etiologies where both patients complained of functional limitation and pain in the shoulder. The first case was caused by a road accident, the second by sequelae of surgery to remove aggressive scapula-axillary fibromatosis. In both patients, therapy with botulin toxin type A (Botox) was performed, which determined a reduction in pain. In the first case, there was also an improvement in function. There were no side effects in the two patients after the injections.

Exposure-dependent increases in IL-1beta, substance P, CTGF, and tendinosis in flexor digitorum tendons with upper extremity repetitive strain injury

Upper extremity tendinopathies are associated with performance of forceful repetitive tasks. We used our rat model of repetitive strain injury to study changes induced in forelimb flexor digitorum tendons. Rats were trained to perform a high repetition high force (HRHF) handle-pulling task (12 reaches/min at 60 +/- 5% maximum pulling force [MPF]), or a low repetition negligible force (LRNF) reaching and food retrieval task (three reaches/min at 5 +/- 5% MPF), for 2 h/day in 30 min sessions, 3 days/week for 3-12 weeks. Forelimb grip strength was tested. Flexor digitorum tendons were examined at midtendon at the level of the carpal tunnel for interleukin (IL)-1beta, neutrophil, and macrophage influx, Substance P, connective tissue growth factor (CTGF), and periostin-like factor (PLF) immunoexpression, and histopathological changes. In HRHF rats, grip strength progressively decreased, while IL-1beta levels progressively increased in the flexor digitorum peritendon (para- and epitendon combined) and endotendon with task performance. Macrophage invasion was evident in week 6 and 12 HRHF peritendon but not endotendon. Also in HRHF rats, Substance P immunoexpression increased in week 12 peritendon as did CTGF- and PLF-immunopositive fibroblasts, the increased fibroblasts contributing greatly to peritendon thickening. Endotendon collagen disorganization was evident in week 12 HRHF tendons. LRNF tendons did not differ from controls, even at 12 weeks. Thus, we observed exposure-dependent changes in flexor digitorum tendons within the carpal tunnel, including increased inflammation, nociceptor-related neuropeptide immunoexpression, and fibrotic histopathology, changes associated with grip strength decline.

Outcome of release of the lateral extensor muscle origin for epicondylitis

Fifty-five elbows in 53 patients affected by lateral epicondylitis for more than a year were operated on with lateral extensor release. Fifty-one patients (53 elbows) were followed-up 90 months postoperatively by two independent observers using Verhaar's score and the subjective grading scheme described by Svernlöv and Adolfsson. According to Verhaar's score 26 (49%) were excellent or good and 27 (51%) fair or poor. Women had significantly worse results than men (p<0.005). In the self-assessment there was no significant difference between men and women and 20 (40%) of the patients rated their elbows as completely recovered, 26 (47%) as improved, 7 (13%) as unchanged, and none as worse. Patients whose symptoms remained unchanged after operation were re-examined and found to have other conditions that were likely to have caused the pain. Lateral release can reduce symptoms in chronic lateral epicondylitis but some residual pain can be anticipated.