Current concepts in imaging of tendinopathy

Patellar tendinopathy: an overview of prevalence, risk factors, screening, diagnosis, treatment and prevention

Patellar tendinopathy (PT), or jumper's knee, is an overuse injury that occurs in professional, as well as recreational, athletes. This condition is a noncontact injury, typically characterized by gradually increasing pain in the patellar tendon. It is prevalent in participants of several sports, but it occurs mostly in jumping sports. The diagnosis of PT is primarily clinical; however, imaging techniques can be useful as well. Risk factors differ between sexes, playing conditions, the kind of sport, playing level and personal characteristics. Screening is an essential tool to assess PT. This condition affects athletic performance and often persists for years. The use of preventative methods is imperative because of the persistence of this condition, especially in elite athletes who sometimes end their career after long and failed treatments. There are a wide variety of treatment and rehabilitation options available, the majority of which are non-operative, such as eccentric exercises, cryotherapy, platelet-rich plasma (PRP) injections, and anti-inflammatory strategies. If conservative treatment fails, surgery is the next most preferable step. Even though there are many surgical treatment methods, there is no clear evidence on what is the most effective approach to address PT. Taking this into consideration, as well as the extent of this clinical entity, novel therapeutic techniques, as well as screening and prevention methods, are expected to emerge in the near future.

The Functions and Mechanisms of Tendon Stem/Progenitor Cells in Tendon Healing

Tendon injury is one of the prevalent disorders of the musculoskeletal system in orthopedics and is characterized by pain and limitation of joint function. Due to the difficulty of spontaneous tendon healing, and the scar tissue and low mechanical properties that usually develops after healing. Therefore, the healing of tendon injury remains a clinical challenge. Although there are a multitude of approaches to treating tendon injury, the therapeutic effects have not been satisfactory to date. Recent studies have shown that stem cell therapy has a facilitative effect on tendon healing. In particular, tendon stem/progenitor cells (TSPCs), a type of stem cell from tendon tissue, play an important role not only in tendon development and tendon homeostasis, but also in tendon healing. Compared to other stem cells, TSPCs have the potential to spontaneously differentiate into tenocytes and express higher levels of tendon-related genes. TSPCs promote tendon healing by three mechanisms: modulating the inflammatory response, promoting tenocyte proliferation, and accelerating collagen production and balancing extracellular matrix remodeling. However, current investigations have shown that TSPCs also have a negative effect on tendon healing. For example, misdifferentiation of TSPCs leads to a "failed healing response," which in turn leads to the development of chronic tendon injury (tendinopathy). The focus of this paper is to describe the characteristics of TSPCs and tenocytes, to demonstrate the roles of TSPCs in tendon healing, while discussing the approaches used to culture and differentiate TSPCs. In addition, the limitations of TSPCs in clinical application and their potential therapeutic strategies are elucidated.

Chronic Lower Leg Pain in Athletes: Overview of Presentation and Management

BACKGROUND

Athletes with chronic lower leg pain present a diagnostic challenge for clinicians due to the differential diagnoses that must be considered.

PURPOSE/QUESTIONS

We aimed to review the literature for studies on the diagnosis and management of chronic lower leg pain in athletes.

METHODS

A literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The PubMed, Scopus, and Cochrane library databases were searched, and articles that examined chronic lower leg pain in athletes were considered for review. Two independent reviewers conducted the search utilizing pertinent Boolean operations.

RESULTS

Following two independent database searches, 275 articles were considered for initial review. After the inclusion and exclusion criteria were applied, 88 were included in the final review. These studies show that the most common causes of lower leg pain in athletes include medial tibial stress syndrome, chronic exertional compartment syndrome, tibial stress fractures, nerve entrapments, lower leg tendinopathies, and popliteal artery entrapment syndrome. Less frequently encountered causes include saphenous nerve entrapment and tendinopathy of the popliteus. Conservative management is the mainstay of care for the majority of cases of chronic lower leg pain; however, surgical intervention may be necessary.

CONCLUSIONS

Multiple conditions may result in lower leg pain in athletes. A focused clinical history and physical examination supplemented with appropriate imaging studies can guide clinicians in diagnosis and management. We provide a table to aid in the differential diagnosis of chronic leg pain in the athlete.

Use of Fat-Suppressed T2-Weighted MRI Images to Reduce the Magic Angle Effect in Peroneal Tendons

INTRODUCTION

Peroneal tendon disorders pose a diagnostic conundrum to the clinician. Magnetic resonance imaging (MRI) is widely used to assess tendon pathology. A recognized artifact of MRI, the magic angle effect (MAE), can lead to spurious results and inappropriate management. The aim of this study is to assess whether T2 fat-suppressed sequences (T2FSs) reduce the frequency of MAE compared with proton density fat-suppressed (PDFS) images.

METHODS

MRI scans of 18 patients were prospectively assessed for MAE. The peroneal tendons were assessed at 5 defined levels on PDFS and T2FS images. The frequency of MAE in the peroneal tendons were compared between the 2 scan sequences.

RESULTS

In the peroneus brevis tendon, 17/72 levels, on PDFS scans, showed MAE compared with 2/72 levels on the T2FS scans, demonstrating a reduction in the MAE by 85% (P = .0003). In the peroneus longus tendon 14/72 levels, on PDFS scans, demonstrated MAE compared with 4/72 on T2FSs, demonstrating a reduction of 71% (P = .02).

CONCLUSION

The inclusion of T2-weighted sequences is useful in MRI scanning for peroneal tendons to mitigate the MAE artifact, avoid potential misdiagnosis, and guide subsequent management of peroneal tendon disorders. Levels of Evidence: Level IV: Case series.

Patellar Tendon Strain Associates to Tendon Structural Abnormalities in Adolescent Athletes

High mechanical strain is thought to be one of the main factors for the risk of tendon injury, as it determines the mechanical demand placed upon the tendon by the working muscle. The present study investigates the association of tendon mechanical properties including force, stress and strain, and measures of tendon micromorphology and neovascularization, which are thought to be indicative of tendinopathy in an adolescent high-risk group for overuse injury. In 16 adolescent elite basketball athletes (14–15 years of age) we determined the mechanical properties of the patellar tendon by combining inverse dynamics with magnetic resonance and ultrasound imaging. Tendon micromorphology was determined based on a spatial frequency analysis of sagittal plane ultrasound images and neovascularization was quantified as color Doppler area. There was a significant inverse relationship between tendon strain and peak spatial frequency (PSF) in the proximal tendon region (r = −0.652, p = 0.006), indicating locally disorganized collagen fascicles in tendons that are subjected to high strain. No such associations were present at the distal tendon site and no significant correlations were observed between tendon force or stress and tendon PSF as well as between tendon loading and vascularity. Our results suggest that high levels of tendon strain might associate to a micromorphological deterioration of the collagenous network in the proximal patellar tendon, which is also the most frequent site affected by tendinopathy. Neovascularization of the tendon on the other hand seems not to be directly related to the magnitude of tendon loading and might be a physiological response to a high frequency of training in this group. Those findings have important implications for our understanding of the etiology of tendinopathy and for the development of diagnostical tools for the assessment of injury risk.

Sonographic Measurement of the Patellar Tendon Should Predict Autograft Bone Patellar Tendon Bone (BPTB) Size: Comparison of Anatomical and Clinical Findings

The use of BPTB autograft is frequently used in ACL reconstruction, however, the risk of potential failure in patients with an anatomically unfavorable patellar tendon may predispose to reconstruction failure. Anatomical study of the extensor apparatus of the knee can provide knowledge about the best option obtain the graft and perform a better preoperative planning. Musculoskeletal ultrasound is a simple, reproducible, affordable technique that could be valid for patellar tendon evaluation. The objective of this study is to evaluate the reproducibility of the patellar tendon measurements by ultrasound and compare them with anatomical measurements, both in cadaver and patients undergoing ACLR. The study consists of two phases; first anatomical study in cadaver. The ultrasound measurement was performed by determining the length, width and thickness of the patellar tendon, both by ultrasound and anatomical dissection. The second phase is a cohort of 42 patients pending surgical ACLR. Previous ultrasound and intraoperative measurements were obtained. Regarding the anatomical study, statistical analysis did not show any differences comparing the measurements in length (p = ns) and thickness (p = ns) of the patellar tendon, although differences were obtained when comparing the results obtained for the width of the tendon after the ultrasound and anatomical measurement (p < 0.001). Same results were obtained in second phase of the study. The reproducibility of ultrasound measurements of the PT is comparable to intraoperatively measurements (without width measurement). These findings can be useful for preoperative planning in the reconstruction of ACL with BPTB Graft and to assess technical modifications prior to surgery.

Magnetic resonance imaging of muscle injury in elite American football players: Predictors for return to play and performance

Muscle injury accounts for about one-third of total sports-related injuries. The lower limb muscles have one of the highest predisposition for injury in high-level professional athletic sports, such as the National Football League. The commonest group of muscles injured among football players include the hamstrings, followed by the quadriceps. Muscle injuries lead to significant time, off the field and affect return to play. Sports physicians and teams have been keen on assessing such injuries and also relying on multiple tools to safely return the player back to the field. MRI plays a key role in evaluation, follow-up, and assessment for return to play (RTP). In this review, we will discuss details of muscle anatomy, incidence of muscle injuries, injury mechanisms, and use of MRI in assessment, grading, follow-up and in predicting the natural course of muscle injuries in the high-end athletic players. While the use of MRI is clear in diagnosis, and for follow up of muscle injuries, there is some limitation in its ability to predict RTP, based on current MRI classification systems. Footballers who have clinical injuries without MRI evidence of significant muscle injury (grade 0 and 1) have a shorter period of RTP. Injuries classified as high grade (3 and 4) on MRI do not correlate well with time to RTP. Further trials are required to improve the capability of MRI in its prediction of RTP.

Lower limb tendinopathy in athletes

Tendinopathy is a common and debilitating problem especially affecting athletes. Understanding of the disease has increased over the past two decades with the most notable change being in the perception that the pathology of tendinopathy is of a noninflammatory origin. The most prevalent aetiological factors implicated in the development of tendinopathy in athletes are overuse and training errors. The commonest lower limb tendinopathy affects the achilles tendon closely followed by patella tendinosis. Achilles tendinopathy is usually seen in running sports whereas patella tendinopathy is commoner in sports that involve jumping. The diagnosis can be confirmed by taking a good history and clinical examination and supported by appropriate radiological imaging. The investigations of choice are ultrasonography and magnetic resonance imaging with each of the investigations having some benefit over the other depending on the questions needing to be answered for the clinician. Treatment of lower limb tendinopathy is mainly conservative and includes activity modification, correction of training errors and eccentric exercises. To date, there have not been any conclusive studies to prove the benefits of nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids which are currently used to help in the management of pain. Surgical treatment has a variable success rate (45—100%) and is normally reserved as the last option if conservative modalities fail. Novel therapies like infection of sclerosing agent, Traumeel®, platelet-derived growth factors (PDGF) or autologous blood injections into diseased tendons are showing promising results but need more multicentre clinical trials to evaluate their efficacy.

Patellar tendon: From tendinopathy to rupture

Patellar tendinopathy is very common in patients complaining of anterior knee pain. Its aetiology is still unclear, but neovascularisation seems to play a role. Different treatments have been proposed overtime, from rehabilitation to platelet-rich-plasma injections, but there is no agreement on the best treatment protocol. The final stage of patellar tendinopathy is patellar tendon rupture. In these cases surgical treatment is often required. The aim of this literature review is to focus on the aetiology, diagnosis, and treatment of both patellar tendinopathy and rupture. We report the conservative treatments proposed for patellar tendinopathy and the surgical techniques described for its rupture.

In vivo monitoring of angiogenesis during tendon repair: a novel MRI-based technique in a rat patellar tendon model

PURPOSE

Recent in vivo studies were able to show the impairing effect of neoangiogenesis in degenerative tendon diseases. Clinical in vivo monitoring of angiogenesis in injured tendons therefore seems to be crucial for an accurate therapeutic approach. The aim of this study was to develop a novel magnetic resonance imaging (MRI)-based technique for observing angiogenesis during tendon healing in vivo.

METHODS

Tendinopathy was induced by an in situ freezing model of rat patellar tendon and monitored after 7, 14, and 28 days. Animals were randomly divided into an imaging and immunohistochemical group. MRI with a 'blood pool' contrast agent was used to determine neoangiogenesis during tendon healing. MRI was compared to histochemical staining and quantification of blood vessels in injured and native tendons.

RESULTS

MRI data revealed a peak in changes in the transverse relaxation rate (ΔR 2*), which is proportional to relative blood volume, 7 days after surgery and decrease until day 28. Histological microvessel density and vascular endothelial growth factor synthesis were also most evident at day 7 and decreased over time.

CONCLUSIONS

The current results are demonstrating a time-dependent correlation between microvessel density and ΔR 2*. Thus, MRI-based evaluation of angiogenesis in the tendon might be a new promising technique for in vivo monitoring of angiogenesis and therapy response in the future.

Lower limb complications of diabetes mellitus: a comprehensive review with clinicopathological insights from a dedicated high-risk diabetic foot multidisciplinary team

Diabetic complications in the lower extremity are associated with significant morbidity and mortality, and impact heavily upon the public health system. Early and accurate recognition of these abnormalities is crucial, enabling the early initiation of treatments and thus avoiding or minimizing deformity, dysfunction and amputation. Following careful clinical assessment, radiological imaging is central to the diagnostic and follow-up process. We aim to provide a comprehensive review of diabetic lower limb complications designed to assist radiologists and to contribute to better outcomes for these patients.

Magnetic resonance imaging of ankle tendon pathology: benefits of additional axial short-tau inversion recovery imaging to reduce magic angle effects

OBJECTIVES

Our goals were to quantify the reduction of the magic angle effect using short-tau inversion recovery (STIR) imaging and to determine the value of adding an axial STIR sequence to the magnetic resonance imaging ankle protocol.

MATERIALS AND METHODS

Axial STIR sequences were used to measure normal tendon T1 and to estimate signal loss due to the inversion recovery preparation of our clinical protocol. In addition, 102 ankles were imaged with axial fat-suppressed intermediate-weighted fast spin echo and STIR sequences. Two radiologists analyzed the tendons for signal intensity, size, abnormalities, and magic angle effect. The diagnostic value and image quality of the two sequences were compared.

RESULTS

We calculated a 50% reduction of signal intensity in healthy tendons on the STIR sequence at TI = 170 ms compared with TI = 0 ms, explaining the decrease in the magic angle effect. Using the STIR sequence, our study demonstrated significantly lower signal intensity within the tendons, more precise tendon size, and a lower magic angle effect compared with the standard intermediate-weighted FSE sequence (p < 0.001). Diagnostic classification of tendon abnormalities using the STIR sequences showed higher sensitivity (82.35% vs. 75.27%) and better agreement with a reference standard than the intermediate-weighted sequences, and superior image quality (p < 0.01).

CONCLUSIONS

Axial STIR sequences reduce magic angle effects and improve visualization of ankle tendon pathology.

In vivo photoacoustic micro-imaging of microvascular changes for Achilles tendon injury on a mouse model

Since neovascularization has been reported that it is associated with tendinopathy, assessments of vascularity are important for both diagnosis and treatment estimation. Photoacoustic imaging, taking the advantages of good ultrasonic resolution and high optical absorption contrast, has been shown a promising tool for vascular imaging. In this study, we explore the feasibility of photoacoustic micro-imaging in noninvasive monitoring of microvascular changes in Achilles tendon injuries on a mouse model in vivo. During collagenase-induced tendinitis, a 25-MHz photoacoustic microscope was used to image microvascular changes in Achilles tendons of mice longitudinally up to 23 days. In addition, complementary tissue structural information was revealed by collateral 25-MHz ultrasound microscopy. Morphological changes and proliferation of new blood vessels in Achilles tendons were observed during and after the acute inflammation. Observed microvascular changes during tendinitis were similar to the findings in the literatures. This study demonstrates that photoacoustic imaging can potentially be a complementary tool for high sensitive diagnosis and assessment of treatment performance in tendinopathy.

An experimental study of low-level laser therapy in rat Achilles tendon injury

The aim of this controlled animal study was to investigate the effect of low-level laser therapy (LLLT) administered 30 min after injury to the Achilles tendon. The study animals comprised 16 Sprague Dawley male rats divided in two groups. The right Achilles tendons were injured by blunt trauma using a mini guillotine, and were treated with LLLT or placebo LLLT 30 min later. The injury and LLLT procedures were then repeated 15 hours later on the same tendon. One group received active LLLT (λ = 904 nm, 60 mW mean output power, 0.158 W/cm² for 50 s, energy 3 J) and the other group received placebo LLLT 23 hours after LLLT. Ultrasonographic images were taken to measure the thickness of the right and left Achilles tendons. Animals were then killed, and all Achilles tendons were tested for ultimate tensile strength (UTS). All analyses were performed by blinded observers. There was a significant increase in tendon thickness in the active LLLT group when compared with the placebo group (p < 0.05) and there were no significant differences between the placebo and uninjured left tendons. There were no significant differences in UTS between laser-treated, placebo-treated and uninjured tendons. Laser irradiation of the Achilles tendon at 0.158 W/cm² for 50 s (3 J) administered within the first 30 min after blunt trauma, and repeated after 15 h, appears to lead to edema of the tendon measured 23 hours after LLLT. The guillotine blunt trauma model seems suitable for inflicting tendon injury and measuring the effects of treatment on edema by ultrasonography and UTS. More studies are needed to further refine this model.

Office-based ultrasound in sports medicine practice

Increasing knowledge, interest, and visibility in the field of sports medicine has equipped clinicians in the field with a novel array of diagnostic and therapeutic options but has also provided a higher level of complexity in patient care. True understanding of the vast spectrum of radiographic technology available to the sports clinician has become more critical than ever. Advances particularly in the areas of magnetic resonance imaging, diagnostic office ultrasound, and 3-dimensional reconstruction computed tomography, as well as nuclear medicine, offer the clinician a myriad of diagnostic options in patient evaluation. As these advances accumulate, the challenge to optimize care, contain cost, and interpret the extensive data generated becomes even more difficult to manage. Improving technology, education, and application of office ultrasound offers an interesting new tool for the bedside evaluation in real time of dynamic motion and pathology of sports-related injuries. As studies continue to validate ultrasound's effectiveness in diagnosing injuries to the upper and lower extremities compared with more costly magnetic resonance imaging and more invasive exploratory surgery, its promise as a cost-effective diagnostic tool is growing. A particularly promising development in the care of sports injuries is the expansion of injection therapies, and in-office ultrasound provides assurance that prolotherapy, platelet-rich plasma, dry needling, corticosteroid, and viscosupplementation are delivered accurately and safely. Communication with patients continues to increase in complexity because a greater understanding of the presence of radiographic abnormalities irrelevant to the current complaint is gained. All the accumulated data must then be interpreted and communicated to the patient with a firm understanding of not only the patient history and physical examination but also the availability, indications, contraindications, sensitivity, specificity, and even the cost implications of the spectrum of diagnostic options.

Imaging of the Achilles tendon in spondyloarthritis: a comparison of ultrasound and conventional, short and ultrashort echo time MRI with and without intravenous contrast

OBJECTIVES

To compare conventional MRI, ultrashort echo time MRI and ultrasound for assessing the extent of tendon abnormalities in spondyloarthritis.

METHODS

25 patients with spondyloarthritis and Achilles symptoms were studied with MRI and ultrasound. MR images of the Achilles tendon were acquired using T1-weighted spin echo, gradient echo and ultrashort echo time (UTE) sequences with echo times (TE) between 0.07 and 16 ms, before and after intravenous contrast medium. Greyscale and power Doppler ultrasound were also performed. The craniocaudal extent of imaging abnormalities measured by a consultant musculoskeletal radiologist was compared between the different techniques.

RESULTS

Abnormalities were most extensive on spoiled gradient echo images with TE = 2 ms. Contrast enhancement after intravenous gadolinium was greatest on the UTE images (TE = 0.07 ms). Fewer abnormalities were demonstrated using unenhanced UTE. Abnormalities were more extensive on MRI than ultrasound. Contrast enhancement was more extensive than power Doppler signal.

CONCLUSIONS

3D spoiled gradient echo images with an echo time of 2 ms demonstrate more extensive tendon abnormalities than the other techniques in spondyloarthritis. Abnormalities of vascularity are best demonstrated on enhanced ultrashort echo time images.

Fluoroscopically guided supraglenoid tubercle steroid injections for the management of biceps tendonitis

BACKGROUND

The management of bicipital tendonitis can be challenging to the clinician. Traditionally, blind injections near the bicipital groove have been performed by clinicians with risk of bicipital tendon rupture or atrophy. Because of the inaccuracy and risk associated with blind bicipital tendon steroid injections, we sought to ascertain whether a fluoroscopically guided steroid injection into the region of the origin of the long head of the bicipital tendon (supraglenoid tubercle) was efficacious.

METHODS

A retrospective chart review of 6 consecutive patients with a diagnosis of bicipital tendonitis was performed. All patients underwent a fluoroscopically guided steroid/anesthetic injection into the supraglenoid tubercle of the shoulder. The main outcome measure was post-procedure change in visual analog pain scale; the secondary outcome was the physical examination (presence of a Speed's test).

RESULTS

Ten cases were identified, but only 6 had complete data and were included in the analysis. Five of the 6 patients experienced a reduction in pain by 50% at follow-up.

DISCUSSION

A fluoroscopically guided block injected into the supraglenoid tubercle may be effective in the management of bicipital tendonitis.

Measurement issues in the sonographic assessment of tennis elbow

Sonography is increasingly being used for assessment in tennis elbow research and clinical practice, but there are a lack of data regarding its validity, reliability, and responsiveness to change for this application. Studies using the modality were reviewed to establish current levels of evidence for these measurement properties. There is reasonable evidence regarding its validity for identifying tennis elbow tendinopathy, but a lack of data addressing its reliability and responsiveness. Practical issues affecting image quality are discussed, and recommendations for further investigation are suggested, to enhance the credible use of sonography with this debilitating condition.

Using ultrasonography to facilitate best practice in diagnosis and management of RA

The key to successful management of rheumatoid arthritis (RA) is early objective quantification of inflammation and ongoing precise, tailored therapy to ensure long term suppression of inflammatory disease activity. Musculoskeletal ultrasonography (MSKUS) has emerged as a tool with the potential to enhance disease assessment and management in this area. This includes applications in patients with undifferentiated arthropathy attending an early inflammatory arthritis clinic, in which the diagnosis of inflammatory disease may be confirmed or refuted at an early stage, and those with treated RA where accurate measurement of outcomes, such as response to therapy, structural damage and disease remission, are extremely important. This imaging modality is safe and portable, making it ideal for outpatient and inpatient settings, and can be used to assess many joints in multiple planes and to demonstrate changes in disease activity and structural damage over time. MSKUS is gaining popularity among rheumatologists, as increasing evidence supports the added value of a physician-performed ultrasonography assessment above traditional clinical, laboratory and radiographic measures, enabling greater confidence in diagnostic and management decisions. Although additional longitudinal data are required and further applications are likely to arise, MSKUS may well possess the necessary attributes to facilitate best practice in inflammatory arthritis management.

Imaging in sports medicine: an overview

Increasing sports participation, and the inevitable sports injury, is a significant contributor to total healthcare expenditure in the United States. With sports-related injury ever increasing, and technology rapidly expanding in the areas of diagnosis and treatment of musculoskeletal trauma, a continual revisiting of the latest in technology is critical for the sports physician. Advances particularly in the areas of magnetic resonance imaging, diagnostic office ultrasound, and 3-dimensional reconstruction computed tomography, offer the clinician a myriad of diagnostic options in patient evaluation. Care must be exercised, however, as one pursues additional radiographic data in the patient care arena. The information must be interpreted with a firm foundation and understanding of not only the patient history and physical examination, but also the availability, indications, contraindications, sensitivity, specificity, and even the cost implications of the great spectrum of diagnostic options.

Achilles and patellar tendinopathy: current understanding of pathophysiology and management

PURPOSE

Achilles and patellar tendinopathy cause significant morbidity in professional and recreational athletes. Both the Achilles and patellar tendons are weight-bearing tendons that lack a true tendon sheath but are surrounded by paratenon.

METHOD

A review of the literature to outline the characteristics of tendinopathy in these two tendons, and to discuss current concepts of pathophysiology, use of imaging in the diagnosis and aid to clinical management strategies in tendinopathy.

RESULTS

Achilles and patellar tendinopathy share common histopathology such as intratendinous failed healing response and neoangiogenesis.

CONCLUSION

Achilles and patellar tendinopathy cause much morbidity in the athletic and non athletic population attending sports medicine and rheumatology clinics. Tendinopathy is essentially an 'overuse', degenerative condition. Neovascularisation evident on Doppler ultrasound correlates well with pain and poor function. Peritendinous injections and eccentric training decrease neovascularity, relieve pain and improve outcome. Although surgery is the last resort in those patients failing conservative management, it is still unclear how the removal of adhesions and excision of affected tendinopathic areas affects healing and vascularity, or resolves pain.

[Overuse syndromes of the foot]

Overuse syndromes due to lifestyle problems or sporting activities commonly lead to foot abnormalities. The tendons of the long flexor and extensor muscles are specifically prone to degeneration. The various disorders may be classified by a grading system that includes peritendinous inflammation, degenerative tendon disease, and ruptures. Bone marrow edema is another typical manifestation of overuse. It may be differentiated from inflammatory or traumatic forms of edema by its anatomic distribution. Systematic pattern recognition is based on the concept of musculotendinous and osseous kinetic chains.

Comparative accuracy of magnetic resonance imaging and ultrasonography in confirming clinically diagnosed patellar tendinopathy

BACKGROUND

Diagnosis of patellar tendinopathy is based primarily on clinical examination; however, it is commonplace to image the patellar tendon for diagnosis confirmation, with the imaging modalities of choice being magnetic resonance imaging (MRI) and ultrasonography (US). The comparative accuracy of these modalities has not been established.

HYPOTHESIS

Magnetic resonance imaging and US have good (>80%) accuracy and show substantial agreement in confirming clinically diagnosed patellar tendinopathy.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Magnetic resonance imaging and US (gray scale [GS-US] and color Doppler [CD-US]) features of 30 participants with clinically diagnosed patellar tendinopathy and 33 activity-matched, asymptomatic participants were prospectively compared. Accuracy, sensitivity, specificity, positive and negative predictive values, and the likelihood of positive and negative test results were determined for each technique.

RESULTS

The accuracy of MRI, GS-US, and CD-US was 70%, 83%, and 83%, respectively (P = .04; MRI vs GS-US). The likelihood of positive MRI, GS-US, and CD-US was 3.1, 4.8, and 11.6, respectively. The MRI and GS-US had equivalent specificity (82% vs 82%; P = 1.00); however, the sensitivity of GS-US was greater than MRI (87% vs 57%; P = .01). Sensitivity (70% vs 87%; P = .06) and specificity (94% vs 82%; P = .10) did not differ between CD-US and GS-US.

CONCLUSIONS

Ultrasonography was more accurate than MRI in confirming clinically diagnosed patellar tendinopathy. GS-US and CD-US may represent the best combination for confirming clinically diagnosed patellar tendinopathy because GS-US had the greatest sensitivity, while a positive CD-US test result indicated a strong likelihood an individual was symptomatic.

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.

INTRAARTERIAL CONTRAST-ENHANCED COMPUTED TOMOGRAPHY OF THE EQUINE DISTAL EXTREMITY

A technique for regional delivery of contrast medium to the foot of the horse to increase the diagnostic utility of computed tomography (CT) for the characterization of soft tissue structures within the hoof capsule was developed. An intraarterial catheter was placed under ultrasound guidance into the medial palmar artery at the level of the carpus to facilitate a steady-state infusion of iodinated contrast medium. Two 5 mm collimated contiguous acquisition CT scans were performed in 10 horses without lameness or radiographic evidence of distal sesamoid bone degeneration. CT examination was performed before and during regional arterial infusion of iodinated contrast medium administered at a rate of 2 ml/s. Cross-sectional area and mean pre- and post-contrast attenuation of the deep digital flexor tendon and the collateral ligaments of the distal interphalangeal joint were quantified from CT images. Soft tissue anatomy of the foot was also qualitatively characterized from pre- and postcontrast images. Catheterization was successful and without complication in all horses. The evaluated tendons and ligaments were clearly visible and had a small (8-20 Hounsfield Unit) but significant (P < 0.05, paired t-test) increase in attenuation during the steady-state infusion of contrast medium. This study should enhance the diagnostic potential of CT by providing baseline quantitative data for comparison with horses affected with soft tissue injuries in the distal extremity causing lameness that is alleviated with a palmar digital nerve block.

Overuse Injuries of the Upper Extremity in the Competitive Athlete: Magnetic Resonance Imaging Findings Associated with Repetitive Trauma

Overuse injuries are a very common cause of pain in athletes, accounting for a significant loss of training time and missed competitions. Magnetic resonance imaging (MRI) is playing an increasing role in facilitating the expeditious and safe return of these individuals to their preinjury level of physical performance by allowing accurate diagnosis. Sports physicians are increasingly relying on the exquisite anatomic detail afforded by this technique to formulate diagnoses that assist with the optimal management of these athletic injuries. Some upper extremity overuse entities are well recognized; two examples are medial epicondylitis, classically appearing in baseball pitchers, and lateral epicondylitis, in tennis players. Other less well-known injuries of the upper extremity, such as intersection syndrome in rowers and distal clavicular stress fractures in weightlifters, are frequent occurrences in certain circles of athletes. The following article is a pictorial review of the MRI findings of upper extremity overuse injuries encountered in the competitive athlete, with an emphasis on the sports scenarios in which they occur. We will depict mechanisms of injury and applicable anatomy and show characteristic imaging findings. A wide range of entities are addressed, including but not limited to overuse injuries occurring in baseball, swimming, gymnastics, weightlifting, bowling, and cycling.

[MR imaging of tendon diseases. Exemplified using the examples of rotator cuff, epicondylitis and achillodynia]

Diseases of tendons have recently increased in importance. This may be due to the increasing popularity of free time sport, but also to the increasing number of treatment possibilities. The origin of damage to the tendons can be explained by a series of mechanisms, of which reduced tissue perfusion and mechanical irritation with microtrauma, which lead to degeneration, can be considered as the most important. Imaging diagnostics plays a significant role in the diagnosis and planning of the therapy of such illnesses. In addition to the conventional x-ray to determine the position of the joint and bony structures, ultrasound can be used to examine the tendons, bursae and tissue.MRI is an excellent method for examining the pathology of tendons due to its exceptional qualities for imaging tissue and joints as well as its high specificity. Using MRI, it is possible to determine the degree of morphological change, make reproducible examinations, as well as determining comorbidity factors or the reasons for the changes early in the illness. It therefore influences surgical decisions and can play a key role in the planning of operations. MRI arthography can-depending on the question-increase the diagnostic power in cases of alterations in the rotator cuff.

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.

Motion-based tendon diagnosis using sequence processing of ultrasound images

Degenerative or pre-degenerative processes in the tendon, which could lead to a spontaneous rupture, are well known problems, especially among athletes. Existing non-invasive diagnostic methods are mainly based on subjective analysis of static images of the tendon, but in many cases the degeneration cannot be diagnosed in time. Combining a set of existing image processing techniques, a tool for tracking the in vivo motion of a tendon imaged with dynamic ultrasound was implemented. A group of subjects that had undergone a degenerative rupture of their Achilles tendon, one subject with a traumatic rupture, and a group of control subjects were all tested. Using the motion information that was obtained from both tendons of all subjects, we developed an automatic test that examines the symmetrical properties of the tendon's motion, and defined a negative asymmetry property that could be quantified as a score. This score was found to be significantly more enhanced in the post-operative tendons (18.0 +/- 9.0) than in the contra-lateral healthy tendons of the same subjects (3.9 +/- 4.6). In the single traumatic rupture subject, this effect was not found (0.0). This leads us to believe that the negative asymmetry of tendon motion may be associated with degenerative or pre-degenerative processes in the tendon. Also, the mean degree of negative asymmetry in the healthy tendons of post-operative subjects (3.9 +/- 4.6) was found to be higher than that of healthy tendons of the control group (1.5 +/- 1.8). This finding may be associated with the fact that tendons that are contra-lateral to spontaneously ruptured tendons have a higher risk of developing degenerative processes. The method presented here is objective, low-cost, non-invasive and possibly more sensitive than existing non-invasive techniques.

Ergonomic Pain--Part 2: Differential Diagnosis and Management Considerations

Work-related musculoskeletal disorders (MSDs) can produce ergonomic pain in several different regions of the body, including the shoulder, elbow, wrist and hand, lumbar spine, knee, and ankle/foot. Each family of disorders is distinctive in presentation and requires diagnosis-specific interventions. Because of the complex nature of these disorders, management approaches may not always eliminate symptoms and or completely restore patient function to a level found prior to symptom onset. As a consequence, ergonomic measures should be implemented to reduce the overload on tissue and contribute to patient recovery. However, functional limits may persist and the clinician must make further decisions regarding a person's functional status in the chronic stages of the patient's care.

On the ultrasonic properties of tendon

The strong dependence of tendon echogenicity on insonation angle is explored by analyzing echo spectra. Combining echo spectra with high-resolution images from several modalities reveals that fluid spaces surrounding fascicles and bundles are likely sources of ultrasonic scatter. Mathematical models of tendon structure are proposed to explain how the anisotropic microstructure of tendon gives rise to angle-dependent echogenicity. Echo spectra from spontaneously damaged equine tendon samples were compared with normal equine tendon and found to exhibit a dramatic decrease in anisotropic properties that appears to be related to the spatial organization and type of collagen generated during repair. Variation in echo spectra with insonation angle is a robust indicator of mechanical damage.