Where is the pain coming from in tendinopathy? It may be biochemical, not only structural, in origin

Novel information on the non-neuronal cholinergic system in orthopedics provides new possible treatment strategies for inflammatory and degenerative diseases

Anti-cholinergic agents are used in the treatment of several pathological conditions. Therapy regimens aimed at up-regulating cholinergic functions, such as treatment with acetylcholinesterase inhibitors, are also currently prescribed. It is now known that not only is there a neuronal cholinergic system but also a non-neuronal cholinergic system in various parts of the body. Therefore, interference with the effects of acetylcholine (ACh) brought about by the local production and release of ACh should also be considered. Locally produced ACh may have proliferative, angiogenic, wound-healing, and immunomodulatory functions. Interestingly, cholinergic stimulation may lead to anti-inflammatory effects. Within this review, new findings for the locomotor system of a more widespread non-neuronal cholinergic system than previously expected will be discussed in relation to possible new treatment strategies. The conditions discussed are painful and degenerative tendon disease (tendinopathy/tendinosis), rheumatoid arthritis, and osteoarthritis.

Clinical and ultrasonographic results of ultrasonographically guided percutaneous radiofrequency lesioning in the treatment of recalcitrant lateral epicondylitis

BACKGROUND

In patients with lateral epicondylitis recalcitrant to nonsurgical treatments, surgical intervention is considered. Despite the numerous therapies reported, the current trend of treatment places particular emphasis on minimally invasive techniques.

PURPOSE

The authors present a newly developed minimally invasive procedure, ultrasonographically guided percutaneous radiofrequency thermal lesioning (RTL), and its clinical efficacy in treating recalcitrant lateral epicondylitis.

CASE SERIES

Level of evidence, 4.

METHODS

Thirty-four patients (35 elbows), with a mean age of 52.1 years (range, 35-65 years), suffered from symptomatic lateral epicondylitis for more than 6 months and had exhausted nonoperative therapies. They were treated with ultrasonographically guided RTL. Patients were followed up at least 6 months by physical examination and 12 months by interview. The intensity of pain was recorded with a visual analog scale (VAS) score. The functional outcome was evaluated using grip strength, the upper limb Disability of Arm, Shoulder and Hand (QuickDASH) outcome measure, and the Modified Mayo Clinic Performance Index (MMCPI) for the elbow. The ultrasonographic findings regarding the extensor tendon origin were recorded, as were the complications.

RESULTS

At the time of the 6-month follow-up, the average VAS score in resting (from 4.9 to 0.9), palpation (from 7.6 to 2.5), and grip (from 8.2 to 2.9) had improved significantly compared with the preoperative condition (P < .01). The grip strength (from 20.6 to 27.0 kg) and QuickDASH score (from 54.3 to 21.0) had also improved significantly (P < .01). The MMCPI score improved from "poor" to "excellent." The ultrasonographic finding revealed that the thickness of the common extensor tendon origin did not change significantly. At the final follow-up (mean, 14.3 months; range, 12-21 months), the patients reported a 78% reduction in pain compared with the preoperative status. No major complications were noted in any patient.

CONCLUSION

Ultrasonographically guided RTL for recalcitrant lateral epicondylitis was found to be a minimally invasive treatment with satisfactory results in this pilot investigation. This innovative method can be considered as an alternative treatment of recalcitrant lateral epicondylitis before further surgical intervention.

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.

Increased expression of cannabinoid CB₁ receptors in Achilles tendinosis

Background

The endogenous cannabinoid system is involved in the control of pain. However, little is known as to the integrity of the cannabinoid system in human pain syndromes. Here we investigate the expression of the cannabinoid receptor 1 (CB₁) in human Achilles tendons from healthy volunteers and from patients with Achilles tendinosis.

Methodology

Cannabinoid CB₁ receptor immunoreactivity (CB₁IR) was evaluated in formalin-fixed biopsies from individuals suffering from painful Achilles tendinosis in comparison with healthy human Achilles tendons.

Principal Findings

CB₁IR was seen as a granular pattern in the tenocytes. CB₁IR was also observed in the blood vessel wall and in the perineurium of the nerve. Quantification of the immunoreactivity in tenocytes showed an increase of CB₁ receptor expression in tendinosis tissue compared to control tissue.

Conclusion

Expression of cannabinoid receptor 1 is increased in human Achilles tendinosis suggesting that the cannabinoid system may be dysregulated in this disorder.

Current opinions on tendinopathy

Tendinopathy is characterized by pain in the tendon and impaired performance sometimes associated with swelling of the tendon. Its diagnosis is usually clinical but ultrasonography and magnetic resonance imaging can refine the diagnosis. Tendinopathy is highly prevalent and is one of the most frequently self reported musculoskeletal diseases in physical workers and sports people. Nevertheless, it is very difficult to carry out general epidemiologic studies on tendinopathy because of the varying sports cultures and sports habits in different countries. The aetiology of tendinopathy seems to be multi-factorial, involving intrinsic and extrinsic factors. The role of inflammation is still debated but the absence of inflammatory cells does not mean that inflammatory mediators are not implicated. Different theories have been advanced to explain pain and chronicity mechanisms, but these mechanisms remain largely unknown. "Conventional "treatments are generally employed empirically to fight pain and inflammation but they do not modify the histological structure of the tendon. However, these treatments are not completely satisfactory and the recurrence of symptoms is common. Currently, eccentric training remains the treatment of choice for tendinopathy, even though some studies are contradictory. Moreover, many interesting new treatments are now being developed to treat tendinopathy, but there is little evidence to support their use in clinical practice. Key pointsThe word "tendinopathy "is the correct term for the clinical diagnosis of pain accompanied by impaired performance, and sometimes swelling in the tendon.The aetiology of tendinopathy seems to be a multi-factorial process, involving promoting factors that are intrinsic or extrinsic, working either alone or in combination.US (with color Doppler) and MRI are usually prescribed when tendinopathy is unresponsive to treatment and entails lingering symptoms.Eccentric training is currently considered to be the most efficient treatment for tendinopathy; nevertheless, in order to be effective, this treatment needs specific modalities: slow speed, low intensity and gradual intensification, with minimum 20 to 30 sessions of exercises often being needed.Many interesting new treatments are now being developed to treat tendinopathy, but currently there is little evidence to support their use in clinical practice.

Marked pathological changes proximal and distal to the site of rupture in acute Achilles tendon ruptures

A laboratory study was performed to evaluate the histopathological features of the macroscopically intact portion of the Achilles tendon in patients undergoing surgery for an acute rupture of the Achilles tendon. Tendon samples were harvested from 29 individuals (21 men, 8 women; mean age: 46 ± 12) who underwent repair of an Achilles tendon tear tear, and from 11 male patients who died of cardiovascular events (mean age: 61). Three pieces of tendon were harvested: at the rupture site, 4 cm proximal to the site of rupture, 1 cm proximal to the insertion of the Achilles tendon on the calcaneum. Slides were assessed using a semiquantitative grading scale assessing fiber structure and arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, and hyalinization. Intra-observer reliability of the subscore readings was calculated. The pathological features were significantly more pronounced in the samples taken from the site of rupture than in the samples taken proximally and distal to it (0.008 < P < 0.01). There were no significant differences in the mean pathologic sum-scores in the samples taken proximally and distal to the site of rupture. Unruptured Achilles tendons, even at an advanced age, and ruptured Achilles tendons are clearly part of two distinct populations, with the latter demonstrating histopathological evidence of failed healing response even in areas macroscopically normal.

Platelet-rich plasma treatment for ligament and tendon injuries

Platelet-rich plasma (PRP) is derived from centrifuging whole blood, has a platelet concentration higher than that of the whole blood, is the cellular component of plasma that settles after centrifugation, and contains numerous growth factors. There is increasing interest in the sports medicine and athletic community about providing endogenous growth factors directly to the injury site, using autologous blood products such as PRP, to potentially facilitate healing and earlier return to sport after musculoskeletal injury. Despite this interest, and apparent widespread use, there is a lack of high-level evidence regarding randomized clinical trials assessing the efficacy of PRP in treating ligament and tendon injuries. Basic science and animal studies and small case series reports on PRP injections for ligament or tendon injuries, but few randomized controlled clinical trials have assessed the efficacy of PRP injections and none have demonstrated scientific evidence of efficacy. Scientific studies should be performed to assess clinical indications, efficacy, and safety of PRP, and this will require appropriately powered randomized controlled trials with adequate and validated clinical and functional outcome measures and sound statistical analysis. Other aspects of PRP use that need to be determined are (1) volume of injection/application, (2) most effective preparation, (3) buffering/activation, (4) injection technique (1 depot vs multiple depots), (5) timing of injection to injury, (6) single application versus series of injections, and (7) the most effective rehabilitation protocol to use after PRP injection. With all proposed treatments, the doctor and the patient should weigh up potential benefits of treatment, potential risks, and costs. Based on the limited publications to date and theoretical considerations, the potential risks involved with PRP are fortunately very low. However, benefits remain unproven to date, particularly when comparing PRP with other injections for ligament and tendon injuries.

Which treatment approach is better for hemiplegic shoulder pain in stroke patients: intra-articular steroid or suprascapular nerve block? A randomized controlled trial

Objective: To determine which injection technique was effective for patients with hemiplegic shoulder pain.

Design: Randomized prospective double-blind study.

Setting: Brain Injury Rehabilitation Unit.

Intervention: Patients with hemiplegic shoulder pain were recruited over a 12-month period and all were hospitalized in our clinic. Intra-articular steroid injection or suprascapular nerve block was performed on all patients.

Main measures: Range of motion values at the moment that pain started (range of motion A) and passive maximum range of motion values (range of motion B) were recorded. Pain intensity levels (visual analogue scale) at these two range of motion values (pain A and pain B) were also taken. Evaluations were made before the injection, and 1 hour, one week and one month after the injection.

Results: Twenty-six patients were enrolled in the study, the mean age was 61.53 ± 10.30 years. The mean time since injury was 8.69 ± 15.71 months. The aetiology was ischaemic in 16 (61%) patients. Intra-articular steroid injection was performed in 11 (42 %) patients, and suprascapular nerve block in 15 (57%) patients. Range of motion A and range of motion B were changed statistically in repeated measures. There were important differences in repeated measures of pain intensity levels at these two range of motion values ( P < 0.05). However, no significant differences were determined in all measurements between intra-articular steroid injection and suprascapular nerve block groups ( P > 0.05).

Conclusions: Our results showed that neither injection technique was superior to the other. Both injection procedures are safe and have a similar effect in stroke patients with hemiplegic shoulder pain.

Mechanical properties of the achilles tendon aponeurosis are altered in athletes with achilles tendinopathy

BACKGROUND

Achilles tendinopathy is a considerable problem for active people. The degenerative processes associated with tendinopathy may be associated with changes in the inherent mechanical properties of the musculotendinous unit.

PURPOSE

The purpose of this study was to compare Achilles tendon-aponeurosis strain between male athletes with and without Achilles tendinopathy.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Fifteen healthy men (age, 35 +/- 9 years; height, 1.78 +/- 0.05 m; mass, 79 +/- 11 kg) and 14 men with midportion Achilles tendinopathy (age, 40 +/- 8 years; height, 1.77 +/- 0.06 m; mass, 80 +/- 9 kg) who were all running over 20 km per week participated in the study. Each participant was tested in a single session that involved maximal isometric plantar flexion efforts being performed on a calf-raise apparatus while synchronous real-time ultrasonography of the triceps surae aponeurosis was recorded. Achilles tendon-aponeurosis strain (%) was calculated by dividing tendon displacement during plantar flexion by resting tendon length (intrarater reliability: intraclass correlation coefficient = .92).

RESULTS

Participants in the Achilles tendinopathy group (5.2% +/- 2.6%) had significantly (P = .039) higher Achilles tendon-aponeurosis strain compared with the control group (3.4% +/- 1.8%). In contrast, there were no significant between-group differences for maximal isometric plantar flexion force.

CONCLUSION

Achilles tendon-aponeurosis strain is higher in male athletes with tendinopathy than those without. The results of this study provide a rationale for current clinical approaches to management of Achilles tendinopathy, whereby repetitive mechanical loading may impart a positive benefit through reduced compliance of the musculotendinous unit.

Ultrasound guided injection of dexamethasone versus placebo for treatment of plantar fasciitis: protocol for a randomised controlled trial

Background

Plantar fasciitis is the most commonly reported cause of chronic pain beneath the heel. Management of this condition commonly involves the use of corticosteroid injection in cases where less invasive treatments have failed. However, despite widespread use, only two randomised trials have tested the effect of this treatment in comparison to placebo. These trials currently offer the best available evidence by which to guide clinical practice, though both were limited by methodological issues such as insufficient statistical power. Therefore, the aim of this randomised trial is to compare the effect of ultrasound-guided corticosteroid injection versus placebo for treatment of plantar fasciitis.

Methods

The trial will be conducted at the La Trobe University Podiatry Clinic and will recruit 80 community-dwelling participants. Diagnostic ultrasound will be used to diagnose plantar fasciitis and participants will be required to meet a range of selection criteria. Participants will be randomly allocated to one of two treatment arms: (i) ultrasound-guided injection of the plantar fascia with 1 mL of 4 mg/mL dexamethasone sodium phosphate (experimental group), or (ii) ultrasound-guided injection of the plantar fascia with 1 mL normal saline (control group). Blinding will be applied to participants and the investigator performing procedures, measuring outcomes and analysing data. Primary outcomes will be pain measured by the Foot Health Status Questionnaire and plantar fascia thickness measured by ultrasound at 4, 8 and 12 weeks. All data analyses will be conducted on an intention-to-treat basis.

Conclusion

This will be a randomised trial investigating the effect of dexamethasone injection on pre-specified treatment outcomes in people with plantar fasciitis. Within the parameters of this protocol, the trial findings will be used to make evidence-based recommendations regarding the use of corticosteroid injection for treatment of this condition.

Trial Registration

Australian New Zealand Clinical Trials Registry. ACTRN12610000239066.

Expression of sensory neuropeptides in tendon is associated with failed healing and activity-related tendon pain in collagenase-induced tendon injury

BACKGROUND

Increase in expression of substance P (SP) and calcitonin gene-related peptide (CGRP) has been reported in clinical samples of tendinopathy.

PURPOSE

To examine the spatial-temporal expression of these neuropeptides as well as their association with activity-related tendon pain, matrix degeneration, failed healing, and pathologic calcification in an established collagenase-induced tendon injury rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Collagenase or saline was injected into the patellar tendon of rats. At weeks 2, 4, 8, 12, and 16, just before the rats were sacrificed, the double-stance duration of rats was examined by gait analysis method. After sacrifice, the patellar tendons were harvested for histologic analysis and immunohistochemical staining of SP and CGRP.

RESULTS

There was an increase of SP and CGRP immunopositivity in tendon fibroblasts at week 2. The immunopositive signals decreased at weeks 4 and 8 and were observed in chondrocyte-like cells. At weeks 12 and 16, the immunopositive staining increased again and was observed in cells embedded in calcific deposits in addition to tendon fibroblasts and chondrocyte-like cells. The expression pattern was consistent with matrix degeneration, calcification, and failed healing in the animal model. There were significant positive correlations of immunopositivity of SP (rho = .502, P = .002) and CGRP (rho = .483, P = .003) with double-stance duration after collagenase injection.

CONCLUSION

There was increased expression of SP and CGRP after collagenase-induced tendon injury, and their expression was positively associated with double-stance duration. Clinical Relevance Substance P and CGRP might be involved in the pathogenesis and origin of pain of tendinopathy and could be the targets for future intervention.

Asymptomatic Achilles tendon pathology is associated with a central fat distribution in men and a peripheral fat distribution in women: a cross sectional study of 298 individuals

Background

Adiposity is a modifiable factor that has been implicated in tendinopathy. As tendon pain reduces physical activity levels and can lead to weight gain, associations between tendon pathology and adiposity must be studied in individuals without tendon pain. Therefore, the purpose of this study was to determine whether fat distribution was associated with asymptomatic Achilles tendon pathology.

Methods

The Achilles tendons of 298 individuals were categorised as normal or pathological using diagnostic ultrasound. Fat distribution was determined using anthropometry (waist circumference, waist hip ratio [WHR]) and dual-energy x-ray absorptiometry.

Results

Asymptomatic Achilles tendon pathology was more evident in men (13%) than women (5%) (p = 0.007). Men with tendon pathology were older (50.9 ± 10.4, 36.3 ± 11.3, p < 0.001), had greater WHR (0.926 ± 0.091, 0.875 ± 0.065, p = 0.039), higher android/gynoid fat mass ratio (0.616 ± 0.186, 0.519 ± 0.142, p = 0.014) and higher upper-body/lower body fat mass ratio (2.346 ± 0.630, 2.022 ± 0.467, p = 0.013). Men older than 40 years with a waist circumference >83 cm had the greatest prevalence of tendon pathology (33%). Women with tendon pathology were older (47.4 ± 10.0, 36.0 ± 10.3, p = 0.008), had less total fat (17196 ± 3173 g, 21626 ± 7882 g, p = 0.009), trunk fat (7367 ± 1662 g, 10087 ± 4152 g, p = 0.003) and android fat (1117 ± 324 g, 1616 ± 811 g, p = 0.005). They had lower central/peripheral fat mass ratios (0.711 ± 0.321 g, 0.922 ± 0.194 g, p = 0.004) than women with normal tendons. Women with tendon pathology were more often menopausal (63%, 13%, p = 0.002).

Conclusions

Men with Achilles tendon pathology were older and had a central fat distribution. Women with tendon pathology were older and had a peripheral fat distribution. An interaction between age and waist circumference was observed among men.

The prevalence of neovascularity in patients clinically diagnosed with rotator cuff tendinopathy

Background

Shoulder dysfunction is common and pathology of the rotator cuff tendons and subacromial bursa are considered to be a major cause of pain and morbidity. Although many hypotheses exist there is no definitive understanding as to the origin of the pain arising from these structures. Research investigations from other tendons have placed intra-tendinous neovascularity as a potential mechanism of pain production. The prevalence of neovascularity in patients with a clinical diagnosis of rotator cuff tendinopathy is unknown. As such the primary aim of this pilot study was to investigate if neovascularity could be identified and to determine the prevalence of neovascularity in the rotator cuff tendons and subacromial bursa in subjects with unilateral shoulder pain clinically assessed to be rotator cuff tendinopathy. The secondary aims were to investigate the association between the presence of neovascularity and pain, duration of symptoms, and, neovascularity and shoulder function.

Methods

Patients with a clinical diagnosis of unilateral rotator cuff tendinopathy referred for a routine diagnostic ultrasound (US) scan in a major London teaching hospital formed the study population. At referral patients were provided with an information document. On the day of the scan (on average, at least one week later) the patients agreeing to participate were taken through the consent process and underwent an additional clinical examination prior to undergoing a bilateral grey scale and colour Doppler US examination (symptomatic and asymptomatic shoulder) using a Philips HDI 5000 Sono CT US machine. The ultrasound scans were performed by one of two radiologists who recorded their findings and the final assessment was made by a third radiologist blinded both to the clinical examination and the ultrasound examination. The findings of the radiologists who performed the scans and the blinded radiologist were compared and any disagreements were resolved by consensus.

Results

Twenty-six patients agreed to participate and formed the study population. Of these, 6 subjects were not included in the final assessment following the pre-scan clinical investigation. This is because one subject had complete cessation of symptoms between the time of the referral and entry into the trial. Another five had developed bilateral shoulder pain during the same period. The mean age of the 20 subjects forming the study population was 50.2 (range 32-69) years (SD = 10.9) and the mean duration of symptoms was 22.6 (range .75 to 132) months (SD = 40.1). Of the 20 subjects included in the formal analysis, 13 subjects (65%) demonstrated neovascularity in the symptomatic shoulder and 5 subjects (25%) demonstrated neovascularity in the asymptomatic shoulder. The subject withdrawn due to complete cessation of symptoms was not found to have neovascularity in either shoulder and of the 5 withdrawn due to bilateral symptoms; two subjects were found to have signs of bilateral neovascularity, one subject demonstrated neovascularity in one shoulder and two subjects in neither shoulder.

Conclusions

This study demonstrated that neovascularity does occur in subjects with a clinical diagnosis of rotator cuff tendinopathy and to a lesser extent in asymptomatic shoulders. In addition, the findings of this investigation did not identify an association between the presence of neovascularity; and pain, duration of symptoms or shoulder function. Future research is required to determine the relevance of these findings.

Endoscopic treatment of chronic mid-portion Achilles tendinopathy: novel technique with short-term results

In this prospective study, we present the short-term clinical results of a novel endoscopic surgical technique for patients suffering from chronic painful mid-portion Achilles tendinopathy. Eight consecutive patients (seven men and one woman, mean age 52 years) diagnosed with chronic painful mid-portion Achilles tendinopathy were included in this study and were treated with endoscopic debridement of the ventral neovascularized area, the peritendineum and the Achilles tendon. Patients recorded the function of the Achilles tendon and the severity of Achilles tendon pain during tendon loading activity, pre and postoperatively in a visual analogue scale. Patient global satisfaction was also assessed in a similar manner. Patients were followed-up for 6 months. All patients experienced immediate postoperative pain relief. In terms of Achilles tendon pain, the median visual analogue score (VAS) increased from 40 (10-60) (preoperatively) to 97.5 (85-100) (last follow-up examination). In terms of Achilles tendon function, the median VAS increased from 22.5 (0-30) (preoperatively) to 90 (80-95) (last follow-up examination). In terms of global satisfaction, the median VAS in the last follow-up examination was 85 (70-95). No postoperative complications were recorded. In conclusion, the short-term clinical results were satisfactory.

From mini-invasive to non-invasive treatment using monopolar radiofrequency: the next orthopaedic frontier

Tendinopathy arises from a failed tendon healing process. Current non-invasive therapeutic alternatives are anti-inflammatory in nature, and outcomes are unpredictable. The benefit of invasive alternatives resides in the induction of the healing response. A new technology that uses non-invasive monopolar capacitive coupled radiofrequency has demonstrated the ability to raise temperatures in tendons and ligaments above 50 degrees C, the threshold for collagen modulation, tissue shrinkage and recruitment of macrophages, fibroblasts, and heat shock protein factors, without damaging the overlying structures, resulting in activation of the wound healing response. Monopolar capacitive-coupled radiofrequency offers a new non-invasive choice for tendinopathies and sprained ligaments. It does not interfere with subsequent surgical procedures should they become necessary.

Management of tendinopathy

Overuse disorders of tendons, or tendinopathies, present a challenge to sports physicians, surgeons, and other health care professionals dealing with athletes. The Achilles, patellar, and supraspinatus tendons are particularly vulnerable to injury and often difficult to manage successfully. Inflammation was believed central to the pathologic process, but histopathologic evidence has confirmed the failed healing response nature of these conditions. Excessive or inappropriate loading of the musculotendinous unit is believed to be central to the disease process, although the exact mechanism by which this occurs remains uncertain. Additionally, the location of the lesion (for example, the midtendon or osteotendinous junction) has become increasingly recognized as influencing both the pathologic process and subsequent management. The mechanical, vascular, neural, and other theories that seek to explain the pathologic process are explored in this article. Recent developments in the nonoperative management of chronic tendon disorders are reviewed, as is the rationale for surgical intervention. Recent surgical advances, including minimally invasive tendon surgery, are reviewed. Potential future management strategies, such as stem cell therapy, growth factor treatment, and gene transfer, are also discussed.

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.

Sonographically guided percutaneous needle tenotomy for treatment of common extensor tendinosis in the elbow: is a corticosteroid necessary?

OBJECTIVE

Chronic refractory common extensor tendinosis of the lateral elbow has been shown to respond to sonographically guided percutaneous needle tenotomy (PNT) followed by corticosteroid injection. In this analysis, we attempted to determine whether the corticosteroid is a necessary component of the procedure.

METHODS

We performed PNT on 57 consecutive patients (age range, 34-61 years) with persistent pain and disability resulting from common extensor tendinosis. Under a local anesthetic and sonographic guidance, a needle was advanced into the tendon, and the tip of the needle was used to fenestrate the tendinotic tissue, break up any calcifications, and abrade the adjacent bone. After the procedure, patients underwent a specified physical therapy protocol. During a subsequent telephone interview, patients answered questions about their symptoms, the level of functioning, and perceptions of the procedure outcome.

RESULTS

Of the 52 patients who agreed to participate in the study, 30 (57.7%) reported excellent outcomes, 18 (34.6%) good, 1 (1.9%) fair, and 3 (5.8%) poor. The average follow-up time from the date of the procedure to the telephone interview was 22 months (range, 7-38 months). No adverse events were reported, and 90% stated that they would refer a friend or close relative for the procedure.

CONCLUSIONS

Sonographically guided PNT for refractory lateral elbow tendinosis is an effective procedure, and subsequent corticosteroid injection is not necessary.

The mechanism for efficacy of eccentric loading in Achilles tendon injury; an in vivo study in humans

OBJECTIVE

Degenerative disorders of tendons present an enormous clinical challenge. They are extremely common, prone to recur and existing medical and surgical treatments are generally unsatisfactory. Recently eccentric, but not concentric, exercises have been shown to be highly effective in managing tendinopathy of the Achilles (and other) tendons. The mechanism for the efficacy of these exercises is unknown although it has been speculated that forces generated during eccentric loading are of a greater magnitude. Our objective was to determine the mechanism for the beneficial effect of eccentric exercise in Achilles tendinopathy.

METHODS

Seven healthy volunteers performed eccentric and concentric loading exercises for the Achilles tendon. Tendon force and length changes were determined using a combination of motion analysis, force plate data and real-time ultrasound.

RESULTS

There was no significant difference in peak tendon force or tendon length change when comparing eccentric with concentric exercises. However, high-frequency oscillations in tendon force occurred in all subjects during eccentric exercises but were rare in concentric exercises (P < 0.0001).

CONCLUSION

These oscillations provide a mechanism to explain the therapeutic benefit of eccentric loading in Achilles tendinopathy and parallels recent evidence from bone remodelling, where the frequency of the loading cycles is of more significance than the absolute magnitude of the force.

Movin and Bonar scores assess the same characteristics of tendon histology

The Movin scoring system and its validated modifications and the Bonar scoring system are used to classify the histopathological findings of tendinopathy. We compared the reliability of these two different histopathological evaluation scores of tendon tissue. Tendon samples were harvested from 88 individuals (49 men, 39 women; mean age, 58.2 years) who underwent arthroscopic repair of a rotator cuff tear, and from five male patients who died of cardiovascular events (mean age, 69.6 years). A piece of supraspinatus tendon that was not directly involved in the tear was harvested en bloc within the intact middle portion of the tendon. Using hematoxylin and eosin staining and Alcian blue, slides were assessed using Bonar and Movin scores. The intraclass correlation was 0.921 (confidence interval 95% 0.790-0.963). Movin's and Bonar's scores have a high correlation and assess similar characteristics and variables of tendon abnormalities.

The influence of the lower patellar pole in the pathogenesis of chronic patellar tendinopathy

Resection of the lower patellar pole provides good results in the treatment of jumper's knee. Therefore we hypothesized that the length of the lower patellar pole is increased in patients with chronic patellar tendinopathy. Cohort study, level of evidence 2. Between 2000 and 2005, 25 patients with chronic patellar tendinopathy underwent conservative and surgical treatment in our clinic. All of them had preoperative MRI were three independent examiners measured the Caton Index, the length and the ratio of the articular and non-articular patellar surface, tendon length and thickness and the thickness and length of the hypodens lesions in the patellar tendon. The measurements were compared with 50 MRI of a control group with no clinical patellofemoral disorders or patellar tendinopathy. Significant changes in tendon thickness (9.42+/-2.87 vs. 4.88+/-1.13; P<0.0001), a longer non-articular surface of the patella (10.62+/-2.86 vs. 7.098+/-2.53; P<0.0001) and significant higher ratio between the articular and the non-articular patellar surface (0.32 vs. 0.24; P<0.0001) were found in the jumper's knee group. No significant changes were seen in the length of the articular surface or the Caton Index. The development of chronic patellar tendinopathy in athletes might be associated with a longer lower patellar pole as patients with jumper's knee showed a longer non-articular patellar surface compared with the control group.

Histopathology of the supraspinatus tendon in rotator cuff tears

BACKGROUND

Causes of rotator cuff pathology are poorly understood.

HYPOTHESIS

Macroscopically intact supraspinatus tendon may show profound light microscopy changes. These changes may be the pathogenic precursor to a subsequent rotator cuff tear.

STUDY DESIGN

Comparative laboratory study.

METHODS

Tendon samples were harvested from 88 individuals (49 men, 39 women; mean age, 58.2 years) who had sustained a rotator cuff tear and underwent arthroscopic repair of the lesion, and from 5 male patients who died of cardiovascular events (mean age, 69.6 years). A full-thickness supraspinatus tendon biopsy specimen was harvested en bloc within the arthroscopically intact middle portion of the tendon between the lateral edge of the tendon tear and the muscle-tendon junction. Slides stained with hematoxylin and eosin were interpreted twice by the same observer using a semiquantitative grading scale assessing fiber structure and arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, and hyalinization. Intraobserver reliability of the subscore readings was calculated.

RESULTS

The mean pathologic sum-score of ruptured tendons was significantly greater than the mean pathologic score of control tendons (15.66 +/- 1.82 vs 3.7 +/- 2.31, P = .001). Within each specific category of tendon abnormalities, the control and ruptured tendons were significantly different (chi(2) test); all variables were significantly different (Mann-Whitney U test <0.05; P = .001). The agreement between the 2 readings ranged from 0.56 to 0.86 (kappa statistics).

CONCLUSION

Nonruptured supraspinatus tendons, even at an advanced age, and ruptured supraspinatus tendons are clearly part of 2 distinct populations.

CLINICAL RELEVANCE

During cuff repair, it is not necessary to excessively freshen the torn tendon to bleeding tissue: the macroscopically intact supraspinatus tendon is degenerated as well, and the failed healing response is not limited to the ends of the torn tendon.

Plantar fasciitis: are pain and fascial thickness associated with arch shape and loading?

BACKGROUND AND PURPOSE

Although plantar fascial thickening is a sonographic criterion for the diagnosis of plantar fasciitis, the effect of local loading and structural factors on fascial morphology are unknown. The purposes of this study were to compare sonographic measures of fascial thickness and radiographic measures of arch shape and regional loading of the foot during gait in individuals with and without unilateral plantar fasciitis and to investigate potential relationships between these loading and structural factors and the morphology of the plantar fascia in individuals with and without heel pain.

SUBJECTS

The participants were 10 subjects with unilateral plantar fasciitis and 10 matched asymptomatic controls.

METHODS

Heel pain on weight bearing was measured by a visual analog scale. Fascial thickness and static arch angle were determined from bilateral sagittal sonograms and weight-bearing lateral foot roentgenograms. Regional plantar loading was estimated from a pressure plate.

RESULTS

On average, the plantar fascia of the symptomatic limb was thicker than the plantar fascia of the asymptomatic limb (6.1+/-1.4 mm versus 4.2+/-0.5 mm), which, in turn, was thicker than the fascia of the matched control limbs (3.4+/-0.5 mm and 3.5+/-0.6 mm). Pain was correlated with fascial thickness, arch angle, and midfoot loading in the symptomatic foot. Fascial thickness, in turn, was positively correlated with arch angle in symptomatic and asymptomatic feet and with peak regional loading of the midfoot in the symptomatic limb.

DISCUSSION AND CONCLUSION

The findings indicate that fascial thickness and pain in plantar fasciitis are associated with the regional loading and static shape of the arch.

Injection therapies for soft-tissue lesions

Local injection therapies, used in the management of a variety of musculoskeletal pain syndromes, include the local infiltration of substances such as corticosteroid, anaesthetic, sclerosants and botulinum toxin, as well as dry needling alone and neural blockade. In this chapter, a number of injection therapies for soft-tissue-mediated pain are described. The reasoning for their use, potential mechanisms of action and unwanted effects are discussed. The literature relating to their effects is critically reviewed. Practical suggestions for their utilisation in the management of soft-tissue conditions are given and proposals are made for future research in this important area.

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.

Excessive apoptosis in patellar tendinopathy in athletes

BACKGROUND

The pathogenesis of tendon overuse injuries is poorly understood. The histopathology underlying tendinopathy at various anatomical locations is similar and may reflect a common pathologic process.

HYPOTHESIS

Apoptosis contributes to the pathophysiology in patellar tendinopathy.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

We compared biopsy specimens from the patellar tendon in patients with patellar tendinopathy diagnosed clinically and with typical magnetic resonance image findings with biopsy specimens from a control group without any previous or current knee complaints to suggest patellar tendinopathy. The presence of apoptosis was examined with immunohistochemical methods using a polyclonal antibody recognizing active caspase-3, confirmed by labeling DNA strand breaks (F7-26 antibody) and nuclear morphology (fragmentation and condensation).

RESULTS

The number of apoptotic cells per unit area (4.5 mm(2)) was 0.91 +/- 0.81 (SD) in tendinopathic samples and 0.21 +/- 0.21 in controls (P = .026). Although the tendinopathic samples displayed increased cellularity (average 162.5 nuclei/mm(2) vs 98.9 nuclei/mm(2)), the apoptotic index was higher (0.42% vs 0.17%, P = .014).

CONCLUSION

Increased apoptotic cell death is a feature of patellar tendinosis. The role of apoptosis within the broader framework and time course of tendon overuse injury remains to be established.

Increased deposition of sulfated glycosaminoglycans in human patellar tendinopathy

OBJECTIVE

To investigate if the increased proteoglycans in patellar tendinopathy involves a qualitative change in the types of proteoglycans.

DESIGN

This is an observational study based on the biochemical analysis of proteoglycans.

SETTING

: University Teaching Hospital.

PATIENTS

Patellar tendon samples from 12 patients with patellar tendinopathy and 12 healthy controls were collected and proteoglycans were extracted for biochemical analyses. All patients fulfilled the diagnostic criteria of having patellar tendinopathy with well-defined clinical features, more than 6 months of insufficient nonoperative treatment including physiotherapeutic modalities, and verification by ultrasound or magnetic resonance imaging. Twelve control subjects, 10 men and 2 women with an average age of 31 years (range 16 to 38 years), represented patients with anterior cruciate ligament deficiency who were operated on using the healthy patellar tendon as an autograft. The control subjects had no previous history or clinical signs of patellar tendon injury.

INTERVENTIONS

The independent variable is the presence of pathological conditions of patellar tendinopathy.

MAIN OUTCOME MEASUREMENTS

The dependent variables include the electromobility of proteoglycans, staining intensity of proteoglycan core proteins, and the tissue content of glycosaminoglycan disaccharides.

RESULTS

The results indicated that the increased proteoglycans in pathological tissues also exhibited qualitative changes as compared to those in healthy patellar tendons. Dermatan monosulfates were significantly increased in the proteoglycans extracted from the pathological tissues of patellar tendinopathy.

CONCLUSIONS

Our results indicate that proteoglycans deposited in the pathological tissues of patellar tendinopathy were oversulfated as compared to healthy tendons, which may represent a new pathological attribute for the understanding of chronic pain in patellar tendinopathy.

The role of stretching in tendon injuries

The function of tendons can be classified into two categories: tensile force transmission, and storage and release of elastic energy during locomotion. The action of tendons in storing and releasing energy is mainly seen in sports activities with stretch-shortening cycles (SSCs). The more intense the SSC movements are (jumping-like activities), the more frequently tendon problems are observed. High SSC movements impose high loads on tendons. Consequently, tendons that frequently deal with high SSC motion require a high energy-absorbing capacity to store and release this large amount of elastic energy. As the elasticity of tendon structures is a leading factor in the amount of stored energy, prevention and rehabilitation programmes for tendon injuries should focus on increasing this tendon elasticity in athletes performing high SSC movements. Recently, it has been shown that ballistic stretching can significantly increase tendon elasticity. These findings have important clinical implications for treatment and prevention of tendon injuries.

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.

Pronociceptive and antinociceptive neuromediators in patellar tendinopathy

BACKGROUND

The occurrence of nerve ingrowth and its relation to chronic tendon pain (tendinopathy) are still largely unknown. In healthy tendons, the innervation is confined to the paratenon, whereas the tendon proper is devoid of nerve fibers. In this study on the pathogenesis of tendinopathy, the authors examined sensory and sympathetic nerve fiber occurrence in the patellar tendon.

HYPOTHESIS

Nerve ingrowth and altered expression of sensory and sympathetic neuromediators play a major role in the pathophysiology of pain in patellar tendinopathy.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

Biopsies from the patellar tendon in patients with patellar tendinopathy (n = 10) were compared with biopsies from a control group (n = 10) without any previous or current knee symptoms compatible with patellar tendinopathy. The biopsies were stained immunohistochemically for sensory and autonomic nerve markers. The biopsies from the 2 groups were compared using subjective and semiquantitative methods.

RESULTS

Chronic painful patellar tendons exhibited increased occurrence of sprouting nonvascular sensory, substance P-positive nerve fibers and a decreased occurrence of vascular sympathetic nerve fibers, positive to tyroxin hydroxylase, a marker for noradrenaline.

CONCLUSION

The altered sensory-sympathetic innervation suggests a role in the pathophysiology of tendinopathy. Ingrowth of sprouting substance P fibers presumably reflects a nociceptive and maybe a proliferative role, possibly as reactions to repeated microtraumata, whereas the decreased occurrence of tyroxin hydroxylase may represent a reduced antinociceptive role. These findings could be used to develop targeted pharmacotherapy for the specific treatment of tendinopathy.

Practical management: nonsteroidal antiinflammatory drug (NSAID) use in athletic injuries

Nonsteroidal antiinflammatory drugs (NSAIDs) are frequently used in the treatment of acute athletic injuries, often for analgesic purposes as the evidence to support enhanced healing is limited. However, the current evidence on NSAID use in athletic injury is slowly growing. On the basis of animal models and limited human studies, some practical management guidelines can be drawn to assist the sports physician. Specifically, NSAIDs are not recommended in the treatment of completed fractures, stress fractures at higher risk of nonunion, or in the setting of chronic muscle injury. The only exception may be very short-term use (eg, a few days) for analgesic purposes only. Judicious use of NSAIDs may be more appropriate in the management of acute ligament sprains, muscle strains, tendinitis, and eccentric muscle injury. However, length of treatment should always be kept as short as possible, with consideration of the specific type of injury, level of dysfunction, and pain.

Current concepts in the management of tendon disorders

Primary disorders of tendons are common and constitute a high proportion of referrals to rheumatologists. Certain tendons are particularly vulnerable to degenerative pathology; these include the Achilles, patella, elements of the rotator cuff, forearm extensors, biceps brachi and tibialis posterior tendons. Disorders of these tendons are often chronic and can be difficult to manage successfully in the long term. Significant advances have been made in understanding the pathophysiology of these conditions. Histopathological evidence, together with advances in imaging techniques, has made us more appreciative of the degenerative (rather that inflammatory) nature of these conditions. Additionally the presence of neovascularization is now well-recognized in long-standing tendinopathy. We review the mechanical, vascular and developing neural theories that attempt to explain the aetiology of degenerative tendinopathy. We also explore theories of why specific tendons (such as the Achilles and supraspinatus tendons) are particularly prone to degenerative pathology. Traditionally, treatments have placed a heavy emphasis on anti-inflammatory strategies, which are often inappropriate. Recently, however, significant advances in the practical management of tendon disorders have been made. In particular the advent of 'eccentric loading' training programmes has revolutionized the treatment of Achilles tendinopathy in some patients. This concept is currently being extended to include other commonly injured tendons. Other current treatments are reviewed, as are potential future treatments.

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.

Neovascularisation and pain in jumper's knee: a prospective clinical and sonographic study in elite junior volleyball players

BACKGROUND

The nature of tendon neovascularisation associated with pain over time has not been studied.

OBJECTIVE

To prospectively study the patellar tendons in elite junior volleyball players.

METHODS

The patellar tendons in all students at the Swedish National Centre for high school volleyball were evaluated clinically and by ultrasonography (US) and Power Doppler (PD) sonography.

RESULTS

Altogether 120 patellar tendons were followed for 7 months. At inclusion, jumper's knee was diagnosed clinically in 17 patellar tendons. There were structural changes on US in 14 tendons, in 13 of which PD sonography showed neovascularisation. There were 70 clinically normal tendons with normal US and PD sonography, 24 clinically normal tendons with abnormal US but normal PD sonography, and nine clinically normal tendons with abnormal US and neovascularisation on PD sonography. At 7 month follow up, jumper's knee was diagnosed clinically and by US in 19 patellar tendons, in 17 of which there was neovascularisation. Three of nine clinically normal tendons with structural changes and neovascularisation at inclusion developed jumper's knee. Two of 24 tendons clinically normal at inclusion, with abnormal US but normal PD sonography, developed jumper's knee with abnormal US and neovascularisation on PD sonography. A total of 20 clinically normal tendons with normal US and PD sonography at inclusion developed structural tendon changes and 12 of these also developed neovascularisation.

CONCLUSIONS

The clinical diagnosis of jumper's knee is most often associated with neovascularisation in the area with structural tendon changes. The finding of neovessels might indicate a deterioration of the condition.

Paratendinopathy

Because most Achilles tendon injuries take place in sports and there has been a general increase in the popularity of sporting activities, the number and incidence of Achilles tendon overuse injuries have increased in the industrialized countries during the last few decades. The term "Achilles paratendinopathy" is used in clinical practice to describe activity-related Achilles pain combined with tenderness on palpation, providing that there is no suspicion of intratendinous pathology on the basis of patient history, clinical examination, or imaging examinations. This article discusses Achilles paratendinopathy.

Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations

Formerly known as 'jumper's knee', patellar tendinopathy gives rise to considerable functional deficit and disability in recreational as well as professional athletes. It can interfere with their performance, often perseveres throughout the sporting career and may be the primary cause to end it. The diagnosis of patellar tendinopathy is primarily a clinical one but new imaging techniques, such as Doppler ultrasonography, may provide additional diagnostic value. Current therapeutic protocols are characterised by wide variability ensuing from anecdotal experience rather than evidence. Moreover, numerous reports in recent years have shattered previous doctrines and dogmatic belief on tendon overuse. Histopathological and biochemical evidence has indicated that the underlying pathology of tendinopathy is not an inflammatory tendinitis but a degenerative tendinosis. Consequently, pain in chronic patellar tendinopathy is not inflammatory in nature, but its exact origin remains unexplained. In pursuit of pathology- and evidence-based management, conservative therapy should be shifted from anti-inflammatory strategies towards a complete rehabilitation with eccentric tendon strengthening as a key element. If conservative management fails, surgery is opted for. However, considering the heterogeneity of surgical procedures and the absence of randomised studies, no conclusive evidence can be drawn from the literature regarding the effectiveness of surgical treatment for patellar tendinopathy. Parallel with the improved knowledge on the pathophysiology and pain mechanisms in patellar tendinopathy, new treatment strategies are expected to emerge in the near future.

Sclerosing injections to areas of neo-vascularisation reduce pain in chronic Achilles tendinopathy: a double-blind randomised controlled trial

Local injections of the sclerosing substance Polidocanol has been demonstrated to give good clinical results in a pilot study on patients with chronic Achilles tendinopathy. In this study, 20 consecutive patients (9 men and 11 women, mean age 50 years) with chronic painful mid-portion Achilles tendinopathy were randomised to injection treatment with either Polidocanol (5 mg/ml) (group A) or Lidocaine hydro-chloride (5 mg/ml) + Adrenaline (5 microg/ml) (group B). Both substances have a local anaesthetic effect, but Polidocanol also has a sclerosing effect. The patients and the treating physician were blinded to the substance injected. The short-term effects were evaluated after a maximum of two treatments, 3-6 weeks apart. Before treatment, all patients had structural tendon changes and neo-vascularisation demonstrated with US and colour doppler. Under US and colour doppler-guidance, the injections targeted the area of neo-vascularisation just outside the ventral part of the tendon. For evaluation, the patients recorded the severity of Achilles tendon pain during tendon loading activity, before and after treatment, on a VAS. Patient's satisfaction with treatment was also assessed. At follow-up (mean 3 months) after a maximum of two treatments, 5/10 patients in group A were satisfied with the treatment and had a significantly reduced level of tendon pain (p < 0.005). In group B, no patient was satisfied with treatment. In the pain-free tendons, but not in the painful tendons, neo-vascularisation was absent after treatment. After completion of the study, treatment with Polidocanol injections (Cross-over in group B and additional treatments in group A) resulted in 10/10 and 9/10 satisfied patients in group A and B, respectively. In summary, injections with the sclerosing substance Polidocanol have the potential to reduce tendon pain during activity in patients with chronic painful mid-portion Achilles tendinopathy.

Prevalence of jumper's knee among elite athletes from different sports: a cross-sectional study

BACKGROUND

The prevalence of jumper's knee across different sports has not been examined, and it is not known if there is a gender difference. Data from surgical case series indicate that there may be a high prevalence in sports with high speed and power demands.

HYPOTHESIS

The aim of this study was to estimate the prevalence of jumper's knee in different sports among female and male athletes and to correlate the prevalence to the loading characteristics of the extensor mechanism in these sports.

STUDY DESIGN

Cross-sectional study; Level of evidence, 4.

METHODS

The authors examined approximately 50 Norwegian male and female athletes at the national elite level from each of the following 9 sports: athletics (male athletes: high jump, 100- and 200-m sprint), basketball (male athletes), ice hockey (male athletes), volleyball (male athletes), orienteering (male athletes), road cycling (male athletes), soccer (male and female athletes), team handball (male and female athletes), and wrestling (male athletes). The examination included an interview on individual characteristics (weight, age, height, and training background), a clinical examination, and self-recorded Victorian Institute of Sport Assessment score from 0 (worst) to 100 (best).

RESULTS

The overall prevalence of current jumper's knee was 14.2% (87 of 613 athletes), with a significant difference between sports with different performance characteristics (range, 0%-45%). In addition, 51 athletes (8%) reported previous symptoms. The prevalence of current symptoms was highest in volleyball (44.6%+/-6.6%) and basketball (31.9%+/-6.8%), whereas there were no cases in cycling or orienteering. The prevalence of current jumper's knee was lower among women (5.6%+/-2.2%) compared with men (13.5%+/-3.0%; chi2 test, P=.042). The duration of symptoms among athletes with current jumper's knee (n=87) was 32+/-25 (standard deviation) months, with a Victorian Institute of Sport Assessment score of 64+/-19.

CONCLUSION

The prevalence of jumper's knee is high in sports characterized by high demands on speed and power for the leg extensors. The symptoms are often serious, resulting in long-standing impairment of athletic performance.

Neovascularisation in chronic painful patellar tendinosis--promising results after sclerosing neovessels outside the tendon challenge the need for surgery

Sclerosing injections targeting neovascularisation have been demonstrated to give promising clinical results in patients with chronic painful Achilles tendinosis. In this study, fifteen elite or recreational athletes (12 men and three women) with the diagnosis patellar tendinosis/Jumper's knee in 15 patellar tendons were included. All the patients had a long duration of pain symptoms (mean = 23 months) from the patellar tendon, and ultra-sonography + colour doppler examination showed structural tendon changes with hypo-echoic areas and a neovascularisation, corresponding to the painful area. The patients were treated with ultrasound and colour doppler-guided injections of the sclerosing substance Polidocanol, targeting the area with neovascularisation. At follow-up (mean = 6 months) after a mean amount of three treatments, there was a good clinical result in 12/15 tendons. The patients were back to their previous (before injury) sport activity level, and the amount of pain recorded on a VAS-scale had decreased significantly (VAS from 81 to 10). Our findings indicate that treatment with sclerosing injections, targeting the area with neovessels in patellar tendinosis, has the potential to cure the pain in the tendons and also allow the patients to go back to full patellar-tendon loading activity.

Disorders of the Achilles tendon and its insertion

This article describes disorders of the Achilles tendon and its insertion.

Similar histopathological picture in males with Achilles and patellar tendinopathy

PURPOSE

To ascertain whether there are differences in the histopathological appearance of tendinopathic Achilles and patellar tendons.

METHODS

In males, we studied biopsies from tendinopathic Achilles (N = 28; average age 34.1 yr) and patellar tendons (N = 28; average age 32.1), Achilles tendons (N = 21; average age 61.8 yr) from deceased patients with no known tendon pathology, and patellar tendons (N = 15; average age 28.3) from patients undergoing anterior cruciate ligament reconstruction. Hematoxylineosin stained slides were interpreted using a semiquantitative grading scale (0: normal to 3: maximally abnormal) for fiber structure, fiber arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, and hyalinization. All slides were assessed blindly twice, the agreement between two readings ranging from 0.170 to 0.750 (kappa statistics).

RESULTS

The highest mean score of tendinopathic Achilles tendons was not significantly different from that of tendinopathic patellar tendons (11.6 +/- 5 and 10.4 +/- 3, respectively). The ability to differentiate between an Achilles tendon and a patellar tendon was low.

CONCLUSIONS

Tendinopathic Achilles and patellar tendons show a similar histological picture. It was not possible to identify whether a specimen had been harvested from an Achilles or a patellar tendon on the basis of histological examination. The general pattern of degeneration was common to both tendinopathic Achilles and patellar tendons. A common, as yet unidentified, etiopathological mechanism may have acted on both these tendon populations.