Vascular NK-1 receptor occurrence in normal and chronic painful Achilles and patellar tendons: studies on chemically unfixed as well as fixed specimens

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.

Radiofrequency Microtenotomy or Physical Therapy for Achilles Tendinopathy: Results of a Randomized Clinical Trial

Background:

Achilles tendinopathy is a painful disorder, and various treatment options are available. Bipolar radiofrequency microtenotomy (RFM) has shown promising results in treating tendinosis.

Purpose/Hypothesis:

The purpose was to compare the results between treatment with bipolar RFM and physical therapy (PT) for patients with midportion Achilles tendinopathy. It was hypothesized that RFM would be equivalent or superior to PT.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 38 patients with midportion Achilles tendinopathy were evaluated for 2 years. The patients were randomized to receive either RFM or PT. There were 20 patients in the RFM group and 18 patients in the PT group. Clinical outcomes were assessed using the visual analog scale (VAS) for pain and the Foot and Ankle Outcome Score (FAOS). The degree of tendinosis was evaluated with magnetic resonance imaging (MRI) of the affected ankle performed before intervention and 2 years after intervention.

Results:

In both groups, the VAS scores at the 2-year follow-up were significantly improved compared with preintervention: from 7.2 ± 1.5 to 1.0 ± 1.4 for the RFM group and from 5.9 ± 1.3 to 3.1 ± 1.8 for the PT group (P < .01 for both). Compared with the PT group, the RFM group had significantly better VAS scores at both the 1- and 2-year follow-ups (P < .01 for both) and better scores on 4 of the 5 FAOS subscales at the 2-year follow-up (P < .01 for all). MRI revealed an improvement in the tendinosis score in both groups, without any significant difference between the groups.

Conclusion:

In this randomized study, the clinical assessments revealed significant improvements in the VAS, FAOS, and tendinosis score as seen on MRI 2 years after intervention with either RFM or PT in patients with midportion Achilles tendinopathy. The improvement was significantly better in the RFM group with regard to VAS and FAOS, but not in the MRI appearance.

Registration:

NCT03274557 (ClinicalTrials.gov identifier).

Clinical and Radiological Outcomes of Operative Therapy in Insertional Achilles Tendinopathy With Debridement and Double-Row Refixation

BACKGROUND

Insertional Achilles tendinopathy (IAT) is a painful pathology in which the strongest and thickest tendon of the human body is affected. Different conservative and operative treatments have been described to address this pathology. This study aimed to evaluate the medium-term clinical and radiological outcomes of patients who underwent a surgical therapy via a longitudinal tendon-splitting approach with debridement and double-row refixation.

METHODS

All patients were assessed pre- and postoperatively using a visual analog scale (VAS), the American Orthopaedic Foot & Ankle Society (AOFAS) Hindfoot Score, the Foot and Ankle Outcome Score (FAOS), and the Foot Function Index (FFI). Additionally, a lateral radiograph of the foot was performed to assess the postoperative result. Forty-two patients with confirmed IAT who underwent surgery between 2013 and 2017 with a longitudinal tendon-splitting approach and tendon refixation using a double-row refixation system were evaluated. The average follow-up was 32.8 (range, 18-52) months. We included 26 female and 16 male patients with an average age of 56.8 (range, 27-73) years.

RESULTS

The mean VAS improved from 8.91 ± 1.0 preoperatively to 1.47 ± 2.5 postoperatively (P< .01). AOFAS scores improved significantly from 51.0 ± 12.5 preoperatively to 91.3 ± 14.3 postoperatively (P< .01). All total and subscores of the FFI and FAOS saw a significant improvement at follow-up (P< .01). Lateral radiographs showed recurrent calcification in 30 patients (71.4%).

CONCLUSION

We found that, at an average of 33 months posttreatment, insertional Achilles tendinopathy via a longitudinal tendon-splitting approach resulted in good outcomes for patients after failure of initial conservative therapy. Recurrent calcification seems to be very common but shows no association with inferior outcomes or the return of symptoms.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Ultrasound-guided tendon debridement improves pain, function and structure in persistent patellar tendinopathy: short term follow-up of a case series

There is a need for effective therapeutic options for resistant patellar tendinopathy. Ultrasound (US)-guided arthroscopic debridement has demonstrated promising clinical results.

Tendinopathy: injury, repair, and current exploration

Both acute and chronic tendinopathy result in high morbidity, requiring management that is often lengthy and expensive. However, limited and conflicting scientific evidence surrounding current management options has presented a challenge when trying to identify the best treatment for tendinopathy. As a result of shortcomings of current treatments, response to available therapies is often poor, resulting in frustration in both patients and physicians. Due to a lack of understanding of basic tendon-cell biology, further scientific investigation is needed in the field for the development of biological solutions. Optimization of new delivery systems and therapies that spatially and temporally mimic normal tendon physiology hold promise for clinical application. This review focuses on the clinical importance of tendinopathy, the structure of healthy tendons, tendon injury, and healing, and a discussion of current approaches for treatment that highlight the need for the development of new nonsurgical interventions.

Sclerosing injections and ultrasound-guided arthroscopic shaving for patellar tendinopathy: good clinical results and decreased tendon thickness after surgery-a medium-term follow-up study

PURPOSE

Treatment of patellar tendinopathy/jumper's knee with ultrasound-guided sclerosing injections or ultrasound-guided arthroscopic shaving has shown good clinical short-term results. Former studies indicate that the tendon thickness and structure stays unaffected after successful treatment. The aim of this study was to evaluate the sonographic findings and clinical outcome 3-5 years after treatment of patellar tendinopathy with ultrasound-guided sclerosing injections or arthroscopic shaving.

METHODS

Fifty-seven patellar tendons (43 patients) with chronic patellar tendinopathy were evaluated, with ultrasound, colour Doppler (CD) and visual analogue scale (VAS) for pain and satisfaction with treatment, 3-5 years after treatment. Functional status was evaluated with a single question-"Back in full loading activity?" yes or no.

RESULTS

At endpoint (mean 46 months), there was a significant decrease in anteroposterior thickness of the proximal patellar tendon in patients treated with ultrasound-guided arthroscopic shaving but not after sclerosing injections. Tendon structure had improved, and CD local blood flow had diminished significantly in both groups. There were good clinical results with a significant decrease in VAS for pain after sclerosing injections (VAS 64 ± 18 → 17 ± 23) with 74 % satisfied patients and also after arthroscopic shaving (VAS 77 ± 16 → 13 ± 23) with 80 % satisfied patients. There were no significant differences in VAS between groups. A significant correlation between low local blood flow and high patient satisfaction was found.

CONCLUSIONS

Tendon thickness decreased over time after ultrasound-guided arthroscopic shaving, and tendon structure and local blood flow decreased after both treatments. There were good, and similar, clinical results with both methods.

LEVEL OF EVIDENCE

III.

The pathogenesis of Achilles tendinopathy: a systematic review

Achilles tendinopathy is a degenerative, not an inflammatory, condition. It is prevalent in athletes involved in running sports. A systematic literature review on Achilles tendon tendinopathy has been performed according to the intrinsic (age, sex, body weight, tendon temperature, systemic diseases, muscle strength, flexibility, previous injuries and anatomical variants, genetic predisposition and blood supply) and extrinsic risk factors (drugs and overuse), which can cause tendon suffering and degeneration. Different theories have been found: Neurogenic, Angiogenic, Impingement and "Iceberg" Hypotheses. Multiple databases were utilized for articles published between 1964 and 2013. The different hypothesis were analyzed, differently considering those concerning the pathogenesis of tendinopathy and those concerning the etiology of complaints in patients. This review of the literature demonstrates the heterogeneity of Achilles tendinopathy pathogenesis. Various risk factors have been identified and have shown an interaction between them such as genes, age, circulating and local cytokine production, sex, biomechanics and body composition.

The peripheral neuronal phenotype is important in the pathogenesis of painful human tendinopathy: a systematic review

BACKGROUND

The pathogenesis of tendinopathy is complex and incompletely understood. Although significant advances have been made in terms of understanding the pathological changes in both the extracellular matrix and the cells involved, relatively little is known about the role of neuronal regulation in tendinopathy. The frequent mismatch between tendon pathology and pain may be explained, in part, by differences in the peripheral neuronal phenotype of patients.

QUESTIONS/PURPOSES

The primary purpose of this review was to determine whether evidence exists of changes in the peripheral neuronal phenotype in painful human tendinopathy and, if so, to identify the associated histological and molecular changes. The secondary purpose was to determine if any changes in the peripheral neuronal phenotype reported correlate with pain symptoms.

METHODS

We conducted a systematic review of the scientific literature using the PRISMA and Cochrane guidelines. The Medline and Embase databases were searched using specific search criteria. Only studies analyzing the peripheral tissue of patients with the clinical diagnosis of tendinopathy were included. Inclusion was agreed on by two independent researchers on review of abstracts or full text.

RESULTS

Overall in the 27 included studies, there was clear evidence of changes in the peripheral neuronal phenotype in painful human tendinopathy. The excitatory glutaminergic system was significantly upregulated in seven studies, there was a significant increase in sensory neuropeptide expression in four studies, and there were significant changes in the molecular morphology of tenocytes, blood vessels, and nerves. In rotator cuff tendinopathy, substance P has been shown to correlate with pain and the neural density in the subacromial bursa has been shown to correlate with rest pain.

CONCLUSIONS

The peripheral neuronal phenotype is an important factor in the pathogenesis of painful human tendinopathy. Further research in this area specifically correlating tissue changes to clinical scores has great potential in further developing our understanding of the disease process.

Heated lidocaine/tetracaine patch for treatment of patellar tendinopathy pain

INTRODUCTION

The pain of patellar tendinopathy (PT) may be mediated by neuronal glutamate and sodium channels. Lidocaine and tetracaine block both of these channels. This study tested the self-heated lidocaine-tetracaine patch (HLT patch) in patients with PT confirmed by physical examination to determine if the HLT patch might relieve pain and improve function.

METHODS

Thirteen patients with PT pain of ≥14 days' duration and baseline average pain scores ≥4 (on a 0-10 scale) enrolled in and completed this prospective, single-center pilot study. Patients applied one HLT patch to the affected knee twice daily for 2-4 hours for a total of 14 days. Change in average pain intensity and interference (Victorian Institute of Sport Assessment [VISA]) scores from baseline to day 14 were assessed. No statistical inference testing was performed.

RESULTS

Average pain scores declined from 5.5 ± 1.3 (mean ± standard deviation) at baseline to 3.8 ± 2.5 on day 14. Similarly, VISA scores improved from 45.2 ± 14.4 at baseline to 54.3 ± 24.5 on day 14. A clinically important reduction in pain score (≥30%) was demonstrated by 54% of patients.

CONCLUSION

The results of this pilot study suggest that topical treatment that targets neuronal sodium and glutamate channels may be useful in the treatment of PT.

Effects on contralateral muscles after unilateral electrical muscle stimulation and exercise

It is well established that unilateral exercise can produce contralateral effects. However, it is unclear whether unilateral exercise that leads to muscle injury and inflammation also affects the homologous contralateral muscles. To test the hypothesis that unilateral muscle injury causes contralateral muscle changes, an experimental rabbit model with unilateral muscle overuse caused by a combination of electrical muscle stimulation and exercise (EMS/E) was used. The soleus and gastrocnemius muscles of both exercised and non-exercised legs were analyzed with enzyme- and immunohistochemical methods after 1, 3 and 6 weeks of repeated EMS/E. After 1 w of unilateral EMS/E there were structural muscle changes such as increased variability in fiber size, fiber splitting, internal myonuclei, necrotic fibers, expression of developmental MyHCs, fibrosis and inflammation in the exercised soleus muscle. Only limited changes were found in the exercised gastrocnemius muscle and in both non-exercised contralateral muscles. After 3 w of EMS/E, muscle fiber changes, presence of developmental MyHCs, inflammation, fibrosis and affections of nerve axons and AChE production were observed bilaterally in both the soleus and gastrocnemius muscles. At 6 w of EMS/E, the severity of these changes significantly increased in the soleus muscles and infiltration of fat was observed bilaterally in both the soleus and the gastrocnemius muscles. The affections of the muscles were in all three experimental groups restricted to focal regions of the muscle samples. We conclude that repetitive unilateral muscle overuse caused by EMS/E overtime leads to both degenerative and regenerative tissue changes and myositis not only in the exercised muscles, but also in the homologous non-exercised muscles of the contralateral leg. Although the mechanism behind the contralateral changes is unclear, we suggest that the nervous system is involved in the cross-transfer effects.

Visceral hypersensitivity in symptomatic diverticular disease and the role of neuropeptides and low grade inflammation

BACKGROUND

  Recurrent abdominal pain is reported by a third of patients with diverticulosis, particularly those with previous episodes of acute diverticulitis. The current understanding of the etiology of this pain is poor. Our aim was to assess visceral sensitivity in patients with diverticular disease and its association with markers of previous inflammation and neuropeptides.

METHODS

  Patients with asymptomatic and symptomatic diverticular disease underwent a flexible sigmoidoscopy and biopsy followed 5-10 days later by visceral sensitivity testing with barostat-mediated rectal distension. Inflammation was assessed by staining of serotonin (5HT) and CD3 positive cells. mRNA levels of tumor necrosis factor alpha (TNF α) and interleukin-6 (IL-6) were quantitated using RT-PCR. Neuropeptide expression was assessed from percentage area staining with substance P (SP) and mRNA levels of the neurokinin 1 & 2 receptors (NK1 & NK2), and galanin 1 receptor (GALR1).

KEY RESULTS

  Thirteen asymptomatic and 12 symptomatic patients were recruited. The symptomatic patients had a lower first reported threshold to pain (28.4 mmHg i.q.r 25.0-36.0) than the asymptomatic patients (47 mmHg i.q.r 36.0-52.5, P < 0.001). Symptomatic patients had a higher median overall pain rating for the stimuli than the asymptomatic patients (P < 0.02). Symptomatic patients had greater median relative expression of NK1 and TNF alpha mRNA compared with asymptomatic patients. There was a significant correlation between barostat VAS pain scores and NK 1 expression (Figure 4, r(2) 0.54, P < 0.02).

CONCLUSIONS & INFERENCES

  Patients with symptomatic diverticular disease exhibit visceral hypersensitivity, and this may be mediated by ongoing low grade inflammation and upregulation of tachykinins.

Substance P is a mechanoresponsive, autocrine regulator of human tenocyte proliferation

It has been hypothesised that substance P (SP) may be produced by primary fibroblastic tendon cells (tenocytes), and that this production, together with the widespread distribution of the neurokinin-1 receptor (NK-1 R) in tendon tissue, could play an important role in the development of tendinopathy, a condition of chronic tendon pain and thickening. The aim of this study was to examine the possibility of endogenous SP production and the expression of NK-1 R by human tenocytes. Because tendinopathy is related to overload, and because the predominant tissue pathology (tendinosis) underlying early tendinopathy is characterized by tenocyte hypercellularity, the production of SP in response to loading/strain and the effects of exogenously administered SP on tenocyte proliferation were also studied. A cell culture model of primary human tendon cells was used. The vast majority of tendon cells were immunopositive for the tenocyte/fibroblast markers tenomodulin and vimentin, and immunocytochemical counterstaining revealed that positive immunoreactions for SP and NK-1 R were seen in a majority of these cells. Gene expression analyses showed that mechanical loading (strain) of tendon cell cultures using the FlexCell© technique significantly increased the mRNA levels of SP, whereas the expression of NK-1 R mRNA decreased in loaded as compared to unloaded tendon cells. Reduced NK-1 R protein was also observed, using Western blot, after exogenously administered SP at a concentration of 10⁻⁷ M. SP exposure furthermore resulted in increased cell metabolism, increased cell viability, and increased cell proliferation, all of which were found to be specifically mediated via the NK-1 R; this in turn involving a common mitogenic cell signalling pathway, namely phosphorylation of ERK1/2. This study indicates that SP, produced by tenocytes in response to mechanical loading, may regulate proliferation through an autocrine loop involving the NK-1 R.

A randomized controlled trial of exercise versus wait-list in chronic tennis elbow (lateral epicondylosis)

BACKGROUND

Chronic tennis elbow (lateral epicondylosis) is a common disorder. Like other chronic soft-tissue pain conditions it is often difficult to treat successfully. The effects of exercise have been discussed, but no convincing evidence has been put forward so far, and a simple protocol for exercise is lacking.

AIMS OF THE STUDY

This study is a randomized, controlled, clinical trial of the effect of exercise versus expectation (wait-list) on pain, muscle strength, function, and quality of life in patients with long-standing lateral epicondylosis.

METHODS

Eighty-one subjects with tennis elbow lasting for more than 3 months were randomly allocated to an exercise group (n = 40) or a reference group (n = 41). The exercise group performed daily exercise, with weekly load increase, for 3 months. The reference group was wait-listed, but otherwise followed in the same way. Outcome measures were pain during maximum voluntary muscle contraction (Cozen's test) and pain during maximum muscle elongation with a load (modified Empty-can-test); muscle strength was measured with a Chatillon MSE 100 hand-held dynamometer, and the Disability of the Arm, Shoulder and Hand (DASH) and the Gothenburg Quality of Life questionnaires.

RESULTS

The exercise group had greater and faster regression of pain, both during muscle contraction and muscle elongation, than the reference group (p = 0.0005 and p = 0.0016, respectively). There was a non-significant muscle strength difference between the groups, but no differences regarding DASH scores or quality of life measures.

CONCLUSIONS

Exercise appears to be superior to expectation in reducing pain in chronic lateral epicondylosis.

Treatment of chronic tendinopathy with ultrasound-guided needle tenotomy and platelet-rich plasma injection

OBJECTIVE

To determine whether ultrasound (US)-guided percutaneous needle tenotomy followed by a platelet-rich plasma (PRP) injection would result in pain reduction, functional improvement, or structural alterations in patients with chronic, recalcitrant tendinopathy.

DESIGN

Part A was a retrospective observational study. Part B was a prospective observational study.

SETTING

Outpatient academic sports medicine center.

PARTICIPANTS

Patients were required to have chronic (>3 months), recalcitrant tendinopathy treated with US-guided percutaneous tenotomy and PRP injection between January 2007 and October 2009. Fifty-one subjects met the inclusion criteria. Forty-one (80%) participated in part A of the study, whereas 34 subjects (67%) participated in part B.

METHODS

In part A, subjects completed a survey obtaining anthropomorphic, demographic, pain, and functional data. Subjects' platelet, hemoglobin, and white blood cell concentrations from their whole-blood and PRP samples were also obtained. In part B, subjects returned to the clinic after US-guided percutaneous needle tenotomy and PRP injection for a diagnostic US, which was compared with their preprocedure diagnostic US.

MAIN OUTCOME MEASURES

The main outcome measures included changes in pain, function, and tendon characteristics.

RESULTS

The tendinopathy location was in the upper extremity in 10 subjects (24.4%), was in the lower extremity in 31 subjects (75.6%), and had been present for a mean of 40 months. The mean postprocedure follow-up was 14 months, and the maximum benefits occurred 4 months postprocedure. There were mean functional and worst-pain improvements of 68% and 58%, respectively. Eighty-three percent of subjects were satisfied with their outcomes and would recommend the procedure to a friend. Although no tendons demonstrated a normal sonographic appearance after the procedure, 84% of subjects had an improvement in echotexture, 64% had a resolution of intratendinous calcifications, and 82% had a decrease in intratendinous neovascularity. None of the variables analyzed in this study demonstrated a significant correlation with pain or functional outcome measures.

CONCLUSIONS

In this case series, we found US-guided percutaneous needle tenotomy followed by PRP injection to be a safe and effective treatment for chronic, recalcitrant tendinopathy, and this treatment was associated with sonographically apparent improvements in tendon morphology. However, because of the intrinsic limitations of the study design and the heterogeneity of treated tendons, further research is required to corroborate our findings.

Mid-portion Achilles tendinopathy: why painful? An evidence-based philosophy

Chronic mid-portion Achilles tendinopathy is generally difficult to treat as the background to the pain mechanisms has not yet been clarified. A wide range of conservative and surgical treatment options are available. Most address intratendinous degenerative changes when present, as it is believed that these changes are responsible for the symptoms. Since up to 34% of asymptomatic tendons show histopathological changes, we believe that the tendon proper is not the cause of pain in the majority of patients. Chronic painful tendons show the ingrowth of sensory and sympathetic nerves from the paratenon with release of nociceptive substances. Denervating the Achilles tendon by release of the paratenon is sufficient to cause pain relief in the majority of patients. This type of treatment has the additional advantage that it is associated with a shorter recovery time when compared with treatment options that address the tendon itself. An evidence-based philosophy on the cause of pain in chronic mid-portion Achilles tendinopathy is presented. Level of evidence V.

Radial shock waves effectively introduced NF-kappa B decoy into rat achilles tendon cells in vitro

The purpose of this study was to test if radial shock waves could enhance the introduction of nuclear factor-kappa B (NF-kappaB) decoy oligodeoxynucleotides, which is reported to markedly inhibit NF-kappaB activation and suppress pro-inflammatory cytokine gene expression, using rat Achilles tendon cells. In the presence of NF-kappaB decoy labeled with or without fluorescein isothiocyanate (FITC) in culture media, radial shock waves were applied to the tendon cells in variable conditions and cultivated for 24 h. The transfection rate was assessed by counting FITC-positive cells, and IL-1-induced NF-kappaB activation in the cells was assessed. Radial shock waves significantly enhanced introduction of NF-kappaB decoy-FITC into the tendon cells. IL-1-induced NF-kappaB activation was significantly inhibited by pretreatment of the cells with NF-kappaB decoy combined with radial shock wave exposure. The present study demonstrated the effectiveness of radial shock waves on introduction of NF-kappaB decoy into tendon cells. Radial shock wave treatment combined with local NF-kappaB decoy administration could be a novel therapeutic strategy for chronic tendinopathy.

The long-term clinical and MRI results following eccentric calf muscle training in chronic Achilles tendinosis

PURPOSE

To evaluate the long-term results following eccentric calf-muscle training in patients with chronic Achilles tendinopathy.

MATERIALS AND METHODS

A total of 24 patients with chronic Achilles tendinopathy were included in a study evaluating MRI findings and clinical symptoms before and after 3 months of daily eccentric calf-muscle strength training. Median duration of symptoms was 18 months (range 6-120). Four of the patients did not perform the prescribed treatment for different reasons and were followed for 14 months. The resulting 20 treated patients completed 4.2-year (range 29-58 months) follow up. Tendon volume was evaluated by using 3D seed growing technique and signal abnormalities were visually semi-quantitatively graded. Level of pain and performance was categorized using a questionnaire completed by the patient.

RESULTS

In the symptomatic treated patients, median intensity level of pain decreased from moderate/severe at time of inclusion to mild at follow up (p < 0.05). Median level of performance increased from severe impairment at time of inclusion to normal at follow up (p < 0.05). 12 out of 20 patients had raised intratendinous signal at time of inclusion compared to 2 out of 20 patients at follow up (p < 0.001). Mean tendon-volume measured 6.7 cm(3) (SD 2.0) at time of inclusion and 6.4 cm(3) (SD 2.0) at follow up (p = 0.18). The four symptomatic non-treated tendons did not improve regarding pain, performance, intratendinous signal or tendon volume.

CONCLUSION

We found decreased pain, improved performance and decreased intratendinous signal both compared to index examination and immediately after the 3 months training regimen in a 4.2-year clinical and MRI follow up, in a group of patients treated with heavy loaded eccentric calf-muscle training for chronic Achilles tendinopathy. The improvements were greater at 4.2-year follow up, despite no further active treatment, than immediately after the treatment. This may indicate a good long-term prognosis for Achilles tendinosis patients.

Pathogenesis of tendinopathies: inflammation or degeneration?

The intrinsic pathogenetic mechanisms of tendinopathies are largely unknown and whether inflammation or degeneration has the prominent role is still a matter of debate. Assuming that there is a continuum from physiology to pathology, overuse may be considered as the initial disease factor; in this context, microruptures of tendon fibers occur and several molecules are expressed, some of which promote the healing process, while others, including inflammatory cytokines, act as disease mediators. Neural in-growth that accompanies the neovessels explains the occurrence of pain and triggers neurogenic-mediated inflammation. It is conceivable that inflammation and degeneration are not mutually exclusive, but work together in the pathogenesis of tendinopathies.

Mid-portion Achilles tendinopathy--current options for treatment

PURPOSE

To report on the present option for management of tendinopathy of the main body of the Achilles tendon.

BACKGROUND

Tendinopathy of the main body of tendo Achillis affects athletic and sedentary patients. Mechanical loading is thought to be a major causative factor. However, the exact mechanical loading conditions which cause tendinopathy are poorly defined. Repetitive mechanical loading induces a non-inflammatory pathology, and repetitive microtrauma ultimately exceeds the healing response. The management of Achilles tendinopathy is primarily conservative. Although many non-operative options are available, few have been tested under controlled conditions. This review article specifically focuses on eccentric training, and on shock wave therapy. Surgical intervention can be successful in refractory cases. However, surgery does not usually completely eliminate symptoms and complications are not rare.

CONCLUSIONS

Further studies are needed to discern the optimal non-operative and surgical management of midsubstance Achilles tendinopathy.

Joint immobilization reduces the expression of sensory neuropeptide receptors and impairs healing after tendon rupture in a rat model

Healing after mobilization versus immobilization was assessed in a model of rat Achilles tendon rupture, by RT-PCR at 8 and 17 days and by histological analyses at 14 and 28 days postrupture. The expression of mRNA for extracellular matrix (ECM) molecules (collagen type I and type III, versican, decorin, and biglycan), and the subjective histological maturation of the healing area were analyzed. Effects of immobilization on healing were related to changes in the peripheral expression of substance P (NK(1))- and calcitonin gene-related peptide (CRLR and RAMP-1)- receptors. At 8 days postinjury, mRNA levels for ECM molecules were equal in both groups. However, by day 17, the ECM mRNA expression in the mobilized group had increased up to approximately 14x that of the immobilized group, which were comparable to intact tendon values. Histological analysis confirmed a higher regenerating activity in the mobilized group, with an increased amount of blood vessels, fibroblasts, and new collagen. The expression of sensory neuropeptide receptors in the mobilized group exhibited a significant increase from 8 to 17 days postinjury similar to the increased ECM mRNA expression, whereas the immobilized group at 17 days exhibited levels comparable to the intact tendon values. Therefore, immobilization postrupture appears to hamper tendon healing, a process which may prove to be directly linked to a downregulated peripheral sensitivity to sensory neuropeptide stimulation.

Neuropeptides in tendinopathy

Overuse tendinopathy remains a major clinical burden for sports medicine and general practitioners. Recent studies have highlighted the role of sensory and autonomic nerves in generating or perpetuating the symptoms and tissue abnormalities associated with tendinopathy. We outline the neuroanatomy and potential roles of nerves and associated neuropeptides in tendinopathy. In addition, intriguing new data is reviewed which suggests that there may be a substantial intrinsic source of neuropeptides within tendons - namely, the tenocytes themselves. The potential roles of Substance P and mast cells are highlighted in particular. We discuss the implications for conservative management including sclerosing injections and exercise training.

Nonoperative treatment of midportion Achilles tendinopathy: a systematic review

OBJECTIVE

The aim of this systematic review is to provide an easily accessible, clear summary of the best available evidence for nonoperative treatment of midportion Achilles tendinopathy.

DATA SOURCES

MEDLINE, CINAHL, and Embase through April 2007. Search terms: achilles tendon or tendo achilles or triceps surae or tendoachilles or tendo-achilles or achilles AND tendinopathy or tendinosis or tendonitis or tenosynovitis.

STUDY SELECTION

Of 707 abstracts reviewed, 16 randomized trials met our inclusion criteria.

DATA EXTRACTION

Data extracted from each paper included: patient demographics (age and sex), duration of symptoms, method of diagnosis, treatments, cohort size, length of follow-up, pain-related outcome data, and secondary outcome data.

DATA SYNTHESIS

The primary outcome measurement was change in numeric pain score. Focal tenderness, tendon thickness, and validated outcome scores were used secondarily. Eccentric exercises were noted to be equivalent to extracorporeal shockwave therapy (1 study) and superior to wait-and-see treatment (2 trials), traditional concentric exercise (2 of 3 trials), and night splints (1 study). Extracorporeal shockwave therapy was shown to be superior to a wait-and-see method in 1 study but not superior to placebo in another. Sclerosing injections were shown to be superior to placebo in 1 study, but local steroid treatment was beneficial in 2 of 3 studies. Injection of deproteinized hemodialysate and topical glyceryl nitrate application were beneficial in 1 trial each.

CONCLUSIONS

Eccentric exercises have the most evidence of effectiveness in treatment of midportion Achilles tendinopathy. More investigation is needed into the utility of extracorporeal shockwave therapy, local corticosteroid treatments, injections of sclerosing agents or deproteinized hemodialysate, and topical glyceryl nitrate application.

Observations favouring the occurrence of local production and marked effects of bombesin/gastrin-releasing peptide in the synovial tissue of the human knee joint--comparisons with substance P and the NK-1 receptor

We have previously shown that levels of the neuropeptides substance P (SP) and bombesin/gastrin-releasing peptide (BN/GRP) in blood and synovial fluid correlate with levels of pro-inflammatory cytokines in patients with rheumatoid arthritis (RA). It is well-established that SP is present in nerve endings in the synovium whilst the source of BN/GRP in human joints is completely unknown. Nor is it known whether GRP-receptors (GRP-R) are present in human synovial tissue. This study aimed to investigate the expression pattern of SP, BN/GRP and their receptors (NK-1R and GRP-R) in synovial tissue. Synovial tissue specimens from patients with RA or osteoarthritis (OA) were processed for immunohistochemistry, in situ hybridisation and ELISA. The results show the presence of BN/GRP, but not SP, in cells in the synovial tissue at both the protein and mRNA level. We did not find immunoreactive BN/GRP in nerve structures. NK-1R and GRP-R were also expressed at both protein and mRNA levels in cells associated with blood vessels and cells in the interstitial tissue. ELISA analyses revealed both SP and BN/GRP to be present in synovial tissue extracts and that synovial levels of SP were higher in RA patients than those with OA. Our results indicate that BN/GRP is produced by non-neuronal cells in the synovial tissue. Furthermore, both BN/GRP and SP may exert their effects on the synovial tissue through the respective receptors. These results suggest that BN/GRP and SP may modulate inflammation and vascular events, and possibly healing processes in the synovium. Finally, nerves should not be considered as the source of BN/GRP in synovial tissue although this peptide is presumably intimately involved functionally in synovial tissue, a previously unrecognised fact.

Presence of substance P and the neurokinin-1 receptor in tenocytes of the human Achilles tendon

Nerve signal substances, such as the tachykinin substance P (SP), may be involved in the changes that occur in response to tendinopathy (tendinosis). It is previously known that the level of SP innervation within tendon tissue is limited, but results of experimental studies have suggested that SP may have stimulatory, angiogenetic and healing effects in injured tendons. Therefore, it would be of interest to know if there is a local SP-supply in tendon tissue. In the present study, the patterns of expression of SP and its preferred receptor, the neurokinin-1 receptor (NK-1 R), in normal and tendinosis human Achilles tendons were analyzed by use of both immunohistochemistry and in situ hybridization. We found that there was expression of SP mRNA in tenocytes, and that tenocytes showed expression of NK-1 R at protein as well as mRNA levels. The observations concerning both SP and NK-1 R were most evident for tenocytes in tendinosis tendons. Our findings suggest that SP is produced in tendinosis tendons, and furthermore that SP has marked effects on the tenocytes via the NK-1 R. It cannot be excluded that the SP effects are of importance concerning the processes of reorganization and healing that occur for tendon tissue in tendinosis. In conclusion, it appears as if SPergic autocrine/paracrine effects occur in tendon tissue during the processes of tendinosis, hitherto unknown effects for human tendons.

Presence of a non-neuronal cholinergic system and occurrence of up- and down-regulation in expression of M2 muscarinic acetylcholine receptors: new aspects of importance regarding Achilles tendon tendinosis (tendinopathy)

Limited information is available concerning the existence of a cholinergic system in the human Achilles tendon. We have studied pain-free normal Achilles tendons and chronically painful Achilles tendinosis tendons with regard to immunohistochemical expression patterns of the M(2) muscarinic acetylcholine receptor (M(2)R), choline acetyltransferase (ChAT), and vesicular acetylcholine transporter (VAChT). M(2)R immunoreactivity was detected in the walls of blood vessels. As evidenced via parallel staining for CD31 and alpha-smooth muscle actin, most M(2)R immunoreactivity was present in the endothelium. M(2)R immunoreactivity also occured in tenocytes, which regularly immunoreact for vimentin. The degree of M(2)R immunoreactivity was highly variable, tendinosis tendons that exhibit hypercellularity and hypervascularity showing the highest levels of immunostaining. Immunoreaction for ChAT and VAChT was detected in tenocytes in tendinosis specimens, particularly in aberrant cells. In situ hybridization revealed that mRNA for ChAT is present in tenocytes in tendinosis specimens. Our results suggest that autocrine/paracrine effects occur concerning the tenocytes in tendinosis. Up-regulation/down-regulation in the levels of M(2)R immunoreactivity possibly take place in tenocytes and blood vessel cells during the various stages of tendinosis. The presumed local production of acetylcholine (ACh), as evidenced by immunoreactivity for ChAT and VAChT and the detection of ChAT mRNA, appears to evolve in response to tendinosis. These observations are of importance because of the well-known vasoactive, trophic, and pain-modulating effects that ACh is known to have and do unexpectedly establish the presence of a non-neuronal cholinergic system in the Achilles tendon.

Substance P and its receptors in bone metabolism

Accumulating evidence on bone physiopathology has indicated that the skeleton contains numerous nerve fibers and its metabolism is regulated by the nervous system. Until now, more than 10 neuropeptides have been identified in bone. Substance P (SP) is a neuropeptide released from axons of sensory neurons, belongs to the tachykinin family and plays important roles in many physiological and pathological processes by acting as a neurotransmitter, neuromodulator, or trophic factor. It activates signal transduction cascades by acting on the neurokinin-1 receptor (NK(1)-R). Previous studies have confirmed that the SP-immunoreactive (IR) axons innervate bone and adjacent tissues, and that their density varies depending on the regions and physiological or pathological conditions. Over the past few decades, it has been found that SP takes part in the stimulation of bone resorption, and its receptors have been demonstrated to be located in osteoclasts. Notably, in studies of skeletal ontogeny, SP-IR axons have been shown to appear at an early stage, mostly coinciding with the sequence of long bone mineralization. These findings, together with data obtained from chemically or surgically targeted nerve deletions, strongly suggest that SP is a potent regulator of skeletal physiology. The specific distribution of SP-IR nerve fibers, the different amount of SP within regions, and the various levels of expression of NK(1)-R in targeted cells presumably related to and participate in bone metabolism. It can be predicted that the indirect roles of SP through other cytokines are as important as its direct roles in bone metabolism. This new regulating pathway of bone metabolism would have enormous implications in skeletal physiology and the relevant research might present curative potentials to a spectrum of bone diseases.

Nerve-related characteristics of ventral paratendinous tissue in chronic Achilles tendinosis

Ultrasound and Doppler examination has shown high blood flow-neovascularisation inside and outside the ventral Achilles tendon in chronic painful tendinosis, but not in pain-free normal Achilles tendons. In patients with Achilles tendinosis, injections with the sclerosing substance polidocanol, targeting the areas with increased blood flow, have been demonstrated to give pain relief. A drawback when interpreting these findings is the fact that the pattern of nerve supply in the target area, i.e. the ventral area of the tendon, is so far unknown. In this study, therefore, tissue specimens from this area, obtained during surgical treatment of patients with chronic painful midportion Achilles tendinosis, were examined. In the examined area, containing loose connective tissue, the general finding was a presence of large and small arteries and nerve fascicles. The nerve fascicles were distinguished in sections processed for the pan-neural marker protein gene-product 9.5. The nerve fascicles contain sensory nerve fibers, as shown via staining for the sensory markers substance P (SP) and calcitonin gene-related peptide, and sympathetic nerve fibers as seen via processing for tyrosine hydroxylase. In addition, there were immunoreactions for the SP-preferred receptor, the neurokinin-1 receptor, in blood vessel walls and nerve fascicles. Some of the blood vessels were supplied by an extensive peri-vascular innervation, sympathetic nerve fibers being a distinct component of this innervation. There was also a marked occurrence of immunoreactions for the alpha1-adrenoreceptor in arterial walls as well as in the nerve fascicles. Altogether, these findings suggest that the area investigated is under marked influence by the nervous system, including sympathetic and sensory components. Thus, sympathetic/sensory influences may be involved in the pain mechanisms from this area. In conclusion, the nerve-related characteristics of the area targeted by the polidicanol injection treatment for Achilles tendinosis, are shown here for the first time.

Are Neuropeptides Important in Arthritis?: Studies on the Importance of Bombesin/GRP and Substance P in a Murine Arthritis Model

Interference with the effects of neuropeptides may be of potential therapeutic value for the treatment of rheumatoid arthritis (RA). Two neuropeptides that can be discussed in this context are bombesin/gastrin-releasing peptide (BN/GRP) and substance P (SP). In order to obtain new information on the possible importance of these two peptides, the patterns of immunohistochemical expression of BN/GRP and SP and their related receptors in the mouse knee joint from healthy and arthritic mice were examined. Positive staining for GRP receptor and the SP preferred receptor (the neurokinin-1 receptor [NK-1 R]) was observed in articular chondrocytes. On the whole, there was a decrease in immunoreactions for both the GRP- and the NK-1 receptors in the articular chondrocytes in joints exhibiting severe arthritis. Staining for BN/GRP and GRP receptor was seen in the inflammatory infiltrates of the arthritic joints. New evidence for the occurrence of marked effects of BN/GRP concerning both the articular chondrocytes and the inflammatory process is obtained in this study. With these findings and previous observations of neuropeptide expression patterns and functions we discuss the possibility that interventions with the effects of BN/GRP, SP, and other neuropeptides might be worthwhile in RA.

Rehabilitation of Achilles and patellar tendinopathies

Achilles and patellar tendinopathies affect a broad range of the population and are difficult conditions to manage clinically. The pathology is persistent in the chronic tendon and can be considered to be failed healing. The exact cause of tendinopathy pain is unclear but may be related to changes in neurovascular structures. Rehabilitation for Achilles and patellar tendinopathies is based on an exercise programme that aims to improve muscle-tendon function and normalise the pelvic/lower limb kinetic chain. This incorporates a programme for restoring and improving muscle strength, endurance and power and retraining sport-specific function. Rehabilitation may take a prolonged period of time, both the athlete and clinician must be patient and persistent to maximise results from an exercise-based treatment.

Studies on the importance of sympathetic innervation, adrenergic receptors, and a possible local catecholamine production in the development of patellar tendinopathy (tendinosis) in man

Changes in the patterns of production and in the effects of signal substances may be involved in the development of tendinosis, a chronic condition of pain in human tendons. There is no previous information concerning the patterns of sympathetic innervation in the human patellar tendon. In this study, biopsies of normal and tendinosis patellar tendons were investigated with immunohistochemical methods, including the use of antibodies against tyrosine hydroxylase (TH) and neuropeptide Y, and against alpha1-, alpha2A-, and beta1-adrenoreceptors. It was noticed that most of the sympathetic innervation was detected in the walls of the blood vessels entering the tendon through the paratendinous tissue, and that the tendon tissue proper of the normal and tendinosis tendons was very scarcely innervated. Immunoreactions for adrenergic receptors were noticed in nerve fascicles containing both sensory and sympathetic nerve fibers. High levels of these receptors were also detected in the blood vessel walls; alpha1-adrenoreceptor immunoreactions being clearly more pronounced in the tendinosis tendons than in the tendons of controls. Interestingly, immunoreactions for adrenergic receptors and TH were noted for the tendon cells (tenocytes), especially in tendinosis tendons. The findings give a morphological correlate for the occurrence of sympathetically mediated effects in the patellar tendon and autocrine/paracrine catecholamine mechanisms for the tenocytes, particularly, in tendinosis. The observation of adrenergic receptors on tenocytes is interesting, as stimulation of these receptors can lead to cell proliferation, degeneration, and apoptosis, events which are all known to occur in tendinosis. Furthermore, the results imply that a possible source of catecholamine production might be the tenocytes themselves

Treatment of Jumper's knee: promising short-term results in a pilot study using a new arthroscopic approach based on imaging findings

Sclerosing injections targeting the area with neovessels and nerves on the dorsal side of the patellar tendon has been demonstrated as giving promising clinical results in patients with chronic painful Jumper's knee-patellar tendinosis (PT). However, a mean number of three treatments with 6-8 weeks in between were needed for a good clinical result. This study aimed to evaluate a more radical removal of the area with neovessels and nerves by using arthroscopic shaving. Fifteen patients (12 men and three women) with the diagnose Jumper's knee-PT in altogether 15 patellar tendons were included. All patients had a long duration of pain-symptoms (mean 27 months) from the patellar tendon, and ultrasonography (US) + colour Doppler (CD) examination showed structural tendon changes with hypo-echoic areas and a neovascularisation inside and on the dorsal side of the tendon, corresponding to the painful area. All patients were treated with arthroscopic shaving of the dorsal side of the proximal tendon. At follow-up (mean 6 months) after treatment, there was a good clinical result in 13/15 tendons (6/8 elite athletes). The satisfied patients were back to previous (before injury) sport activity level, and the amount of pain recorded on a visual analogue scale (VAS)-scale had decreased significantly (VAS from 79 to 12, P < 0.05). A telephone follow-up 13 months (mean) postoperatively showed that the same 13/15 were still satisfied and active in their sports, and that the 2/15 poor cases were still not satisfied with the treatment. Our short-term results indicate that arthroscopic shaving targeting the area with neovessels and nerves on the dorsal side of the patellar tendon has a potential to reduce the tendon pain and allow for the majority of patients to go back to full tendon loading activity within 2 months after surgery. Further studies evaluating this new technique for treating Jumper's knee-PT are in progress.

A treatment algorithm for managing Achilles tendinopathy: new treatment options

Achilles tendinopathy affects athletes, recreational exercisers and even inactive people. The pathology is not inflammatory; it is a failed healing response. The source of pain in tendinopathy could be related to the neurovascular ingrowth seen in the tendon's response to injury. The treatment of Achilles tendinopathy is primarily conservative with an array of effective treatment options now available to the primary care practitioner. If conservative treatment is not successful, then surgery relieves pain in the majority of cases. Directing a patient through the algorithm presented here will maximise positive treatment outcomes.

Immunohistochemical and histochemical findings favoring the occurrence of autocrine/paracrine as well as nerve-related cholinergic effects in chronic painful patellar tendon tendinosis

The pathogenesis of the pain in patellar tendon tendinosis ("jumper's knee") is unclear. We have recently presented new information about the sensory nervous system in the human patellar tendon, but there is very little information regarding the possible occurrence of a cholinergic system in this tendon. In the present study, specimens of pain-free normal tendons and chronically painful tendinosis tendons were examined by different immunohistochemical and histochemical methods. Antibodies against the M(2) receptor, choline acetyltransferase (ChAT), and vesicular acetylcholine transporter (VAChT) were applied, and staining for demonstration of activity of acetylcholinesterase (AChE) was also utilized. It was found that immunoreactions for the M(2) receptor could be detected intracellularly in both blood vessel cells and tenocytes, especially in tendinosis specimens. Furthermore, in the tendinosis specimens, some tenocytes were seen to exhibit immunoreaction for ChAT and VAChT. AChE reactions were seen in fine nerve fibers associated with small blood vessels in both the normal control tendons and the tendinosis tendons. The observations suggest that there is both a nerve related and a local cholinergic system in the human patellar tendon. As ChAT and VAChT immunoreactions were detected in tenocytes of tendinosis tendons, these cells might be a source of local acetylcholine (Ach) production. As both tenocytes and blood vessel cells were found to exhibit immunoreactions for the M(2) receptor, it is likely that both of these tissue cells may be influenced by ACh. Thus, in conclusion, there appears to be an upregulation of the cholinergic system, and an occurrence of autocrine/paracrine effects in this system, in the tendinosis patellar tendon.

Sclerosing polidocanol injections in mid-portion Achilles tendinosis: remaining good clinical results and decreased tendon thickness at 2-year follow-up

The short-term results after treatment with sclerosing polidocanol injections have been shown to be good in patients with chronic painful mid-portion Achilles tendinosis. This study aimed to evaluate the longer-term effects on tendon thickness, structure and vascularity, patient satisfaction with treatment, and pain during tendon loading activity. Ultrasonography (US) + colour Doppler (CD) was used for evaluation of the tendon, and the patients graded the amount of pain during tendon loading activity on a VAS. Forty-two patient's tendons (23 men and 19 women, mean age 53 years) with a long duration (mean 32 months) of pain symptoms from mid-portion Achilles tendinosis (US + CD showed a localised thickening, structural changes and neovascularisation), were at three (mean) occasions (6-8 weeks in between) treated with US and CD guided injections of the sclerosing substance polidocanol, targeting the area with neovessels ventral to the tendon. After treatment, 37 patients were satisfied with the results of the treatment and back to previous (before injury) activity level. At the 2-year follow-up (mean 23 months), 38 patients were satisfied with the results of the treatment, and there was a significant reduction in VAS (from 75 to 7; P < 0.05). US showed a significant reduction in the mean mid-portion tendon thickness (from 10 to 8 mm, P < 0.05) and a "more normal" structure. CD showed no, or a few, remaining neovessels in the majority of the successfully treated tendons. In conclusion, treatment with sclerosing polidocanol injections in patients with chronic painful mid-portion Achilles tendinosis showed remaining good clinical results at a 2-year follow-up. Decreased tendon thickness and improved structure after treatment, might indicate a remodelling potential?

Normal clinical and ultrasound findings indicate a low risk to sustain jumper's knee patellar tendinopathy: a longitudinal study on Swedish elite junior volleyball players

BACKGROUND

Jumper's knee patellar tendinopathy is well known to be a common and difficult injury in volleyball. Knowledge about its aetiology and pathogenesis is sparse.

OBJECTIVE

To prospectively follow clinical status, tendon structure and vascularity in elite junior volleyball players.

METHODS

22 volleyball players (44 patellar tendons) beginning their first grade at the Swedish National Centre for high school volleyball were continuously evaluated clinically and by ultrasonography (US) and power Doppler (PD) over the 3 school years.

RESULTS

At inclusion, there were 44 tendons being assessed. Jumper's knee was diagnosed clinically in eight patellar tendons (seven of eight had structural changes and vascularity on US+PD). There were 27 normal (clinical and US+PD) tendons. At 3 years, there were 36 tendons still being assessed. Four individuals (eight tendons) had been excluded. Jumper's knee had developed in 2 of 25 (2 were excluded) tendons that were normal (clinical and US+PD) at inclusion. Jumper's knee (clinical and US+PD) was also present in six tendons.

CONCLUSIONS

Normal clinical tests and ultrasound findings at the start indicated a low risk for these elite junior volleyball players to sustain jumper's knee during three school years with intensive training and playing.

Sclerosing polidocanol injections in chronic painful tennis elbow-promising results in a pilot study

Sclerosing polidocanol injections targeting the area with neovessels (vascularity) have been demonstrated to give promising clinical results in patients with chronic painful Achilles and patellar tendinosis. Recently, we demonstrated vascularity in the extensor origin in patients with chronic painful tennis elbow, but not in controls with pain-free elbows. In this pilot study, 11 patients (four men and seven women, mean age 46 years) with the diagnosis of tennis elbow in altogether 13 elbows, were included. All patients had a long duration of pain symptoms (mean 23 months), and ultrasonography (US) + colour Doppler (CD) examination showed structural tendon changes with hypo-echoic areas, and a vascularity, corresponding to the painful area in the extensor origin. All patients were treated with US- and CD-guided injections of the sclerosing substance polidocanol, targeting the area with vascularity. At 8-month follow-up after treatment, there was a good clinical result in 11/13 elbows. Extensor origin pain during wrist loading activities (recorded on a VAS-scale) was significantly reduced (mean VAS from 75 to 34; P < 0.003), and maximal grip strength was significantly increased (from 29 to 40 kg; P < 0.025). Our findings indicate that one treatment with sclerosing polidocanol injections, targeting the area with vascularity in the extensor origin, has a potential to reduce the tendon pain and increase grip strength, in patients with chronic painful tennis elbow.

Extensor origin vascularity related to pain in patients with Tennis elbow

Tennis elbow, extensor carpi radialis brevis (ECRB) tendinosis, is a condition with unknown etiology and pathogenesis, known to be difficult to treat. The pain mechanisms have not been fully clarified, but involvement of a neurogenic inflammation mediated via the neuropeptide Substance-P (SP), has been suggested. In this investigation, grey-scale ultrasonography (US) and colour Doppler (CD) was used to examine the common extensor origin in 17 patients with the diagnose Tennis elbow in altogether 22 elbows, and in 11 controls with 22 pain-free elbows. In 21/22 elbows with chronic pain from the extensor origin, but only in 2/22 pain-free elbows, vascularity was demonstrated in the extensor origin. After US and CD-guided injection of a local anaesthetic, targeting the area with vessels, the patients were pain-free during extensor-loading activity. The area with vascularity found in the extensor origin seems to be related to pain. Most likely, the findings correspond with the vasculo-neural in growth that has been demonstrated in the chronic painful Achilles tendon, and possibly have implications for treatment.

Distribution of general (PGP 9.5) and sensory (substance P/CGRP) innervations in the human patellar tendon

There is no information on the pattern of blood vessel innervation, and in principle no information on innervation in general, in the human patellar tendon. In the present study, biopsies from the proximal part of normal and pain-free patellar tendons (11 men, mean age 33 years) were examined. The specimens were evaluated by using antibodies against the general nerve marker protein gene-product 9.5 (PGP 9.5) and the sensory neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP), and immunohistochemistry. It was observed that the arteries, and to some extent the small vessels, in the loose paratendinous connective tissue were supplied with PGP 9.5- as well as SP- and CGRP-innervations. There was a marked PGP 9.5-like immunoreaction (LI), and to some extent also SP- and CGRP-LI, in the large nerve fascicles in this tissue. In the tendon tissue proper, PGP 9.5-LI was detected in nerve fibers located in the vicinity of some of the blood vessels and in thin nerve fascicles. There was a low degree of SP- and CGRP-innervation in the tendon tissue proper. The observations give a morphologic correlate for the occurrence of nerve-mediated effects in the patellar tendon. Particularly it seems as if there is a marked nerve-mediated regulation of the blood vessels supplying the tendon, at the level where they course in the loose paratendinous connective tissue.

Superior results with eccentric compared to concentric quadriceps training in patients with jumper's knee: a prospective randomised study

BACKGROUND

A recent study reported promising clinical results using eccentric quadriceps training on a decline board to treat jumper's knee (patellar tendinosis).

METHODS

In this prospective study, athletes (mean age 25 years) with jumper's knee were randomised to treatment with either painful eccentric or painful concentric quadriceps training on a decline board. Fifteen exercises were repeated three times, twice daily, 7 days/week, for 12 weeks. All patients ceased sporting activities for the first 6 weeks. Age, height, weight, and duration of symptoms were similar between groups. Visual analogue scales (VAS; patient estimation of pain during exercise) and Victorian Institute of Sport Assessment (VISA) scores, before and after treatment, and patient satisfaction, were used for evaluation.

RESULTS

In the eccentric group, for 9/10 tendons patients were satisfied with treatment, VAS decreased from 73 to 23 (p<0.005), and VISA score increased from 41 to 83 (p<0.005). In the concentric group, for 9/9 tendons patients were not satisfied, and there were no significant differences in VAS (from 74 to 68, p<0.34) and VISA score (from 41 to 37, p<0.34). At follow up (mean 32.6 months), patients in the eccentric group were still satisfied and sports active, but all patients in the concentric group had been treated surgically or by sclerosing injections.

CONCLUSIONS

In conclusion, eccentric, but not concentric, quadriceps training on a decline board, seems to reduce pain in jumper's knee. The study aimed to include 20 patients in each group, but was stopped at the half time control because of poor results achieved in the concentric group.

The chronic painful Achilles and patellar tendon: research on basic biology and treatment

The etiology and pathogenesis of chronic tendon pain are unknown. Even though tendon biopsies having shown an absence of inflammatory cell infiltration, anti-inflammatory agents (non-steroidal anti-inflammatory drugs, corticosteroidal injections) are commonly used. We have demonstrated that it is possible to use intratendinous microdialysis to investigate human tendons, and found normal prostaglandin E2 (PGE2) levels in chronic painful tendinosis (Achilles and patellar) tendons. Furthermore, gene technological analyses of biopsies showed no upregulation of pro-inflammatory cytokines. These findings show that there is no PGE2-mediated intratendinous inflammation in the chronic stage of these conditions. The neurotransmitter glutamate (a potent modulator of pain in the central nervous system) was, for the first time, found in human tendons. Microdialysis showed significantly higher glutamate levels in chronic painful tendinosis (Achilles and patellar) tendons, compared with pain-free normal control tendons. The importance of this finding is under evaluation. Treatment is considered to be difficult, and not seldom, surgery is needed. However, recent researches on non-surgical methods have shown promising clinical results. Painful eccentric calf-muscle training has been demonstrated to give good clinical short- and mid-term results on patients with chronic painful mid-portion Achilles tendinosis. Good clinical results were associated with decreased tendon thickness and a structurally more normal tendon with no remaining neovessels. Using ultrasonography (US)+color Doppler (CD), and immunhistochemical analyses of biopsies, we have recently demonstrated a vasculo/neural (Substance-P and Calcitonin Gene-Related Peptide nerves) ingrowth in the chronic painful tendinosis tendon, but not in the pain-free normal tendon. A specially designed treatment, using US- and CD-guided injections of the sclerosing agent Polidocanol, targeting the neovessels outside the tendon, has been shown to cure tendon pain in pilot studies, in a majority of the patients. A recent, randomized, double-blind study verified the importance of injecting the sclerosing substance Polidocanol.