MR imaging of disorders of the Achilles tendon

Soft tissue mass resembling myxochondroid metaplasia in Achilles tendon

The Achilles tendon is the strongest and largest tendon in the human body, composed of the distal confluence of the gastrocnemius and soleus muscles and may also include the plantaris longus tendons. Despite its tremendous strength, it is frequently injured. Soft tissue tumors or tumor-like conditions of Achilles tendon are much less common in comparison to traumatic and infectious/inflammatory lesions. These include giant cell tumor of the tendon sheath, pigmented villonodular synovitis, xanthomas, hematomas, and tophaceous gout. We present a case of a myxochondroid mass arising from the Achilles tendon in a 17-year-old female softball player detected after a minor trauma. According to our knowledge, this is the first case reported in the literature detailing the radiological findings and histopathological diagnosis of a myxochondroid mass arising from a tendon.

Assessment of calf muscle constitution in chronic Achilles tendon disease using Dixon-based MRI

OBJECTIVES

To assess calf muscle constitution in chronic Achilles tendon disease (ATD) using two-point Dixon-based MRI (2pt-MRIDIXON).

MATERIALS AND METHODS

This retrospective study analyzed 91 patients (36 females; 57.0 ± 14.4 years) with midportion or insertional chronic ATD who underwent clinical MRI of the Achilles tendon (AT), including 2pt-MRIDIXON for quantitative assessment of calf muscle fat content (MFC). Additionally, two radiologists qualitatively assessed MFC, AT quality, and co-pathologies. 2pt-MRIDIXON-derived fat fractions (FF) were related to patients' demographics and qualitative imaging findings.

RESULTS

The overall mean FF derived from 2pt-MRIDIXON of the triceps surae muscle was 11.2 ± 9.3%. Comparing midportion and insertional ATD, there was no significant difference regarding fatty muscle infiltration assessed with 2pt-MRIDIXON (P ≥ .47) or qualitative grading (P ≥ .059). More severe AT thickening (11 vs.9 mm, P < .001) and complete tears (29 vs. 9%, P = .025) were significantly more common in midportion ATD, while partial tears were significantly more frequent in insertional ATD (55 vs. 31%, P = .027). Soleus muscle edema was more prevalent in midportion than insertional ATD (40 vs. 9%, P = .002). In contrast, insertional ATD more commonly featured bone marrow edema (61 vs. 2%), Haglund's deformity (67 vs. 0%), and retrocalcaneal bursitis (82 vs. 43%) (P ≤ .002). Significant correlations (P ≤ .001) were demonstrated between FF, AT diameter, age (both in midportion and insertional ATD), and body mass index (in midportion ATD only) (ρ range = 0.53-0.61).

CONCLUSION

In chronic ATD, calf MFC was statistically equivalent (approximately 11%), irrespective of the localization of tendon damage. More severe tendon thickening and complete tears were more common in midportion ATD, and, vice versa, partial AT tears were significantly more frequent in insertional ATD.

Effect of Platelet-Rich Plasma Injection on the Treatment of Achilles Tendinopathy: A Systematic Review and Meta-analysis

Background

Achilles tendinopathy is a common condition without a reproducible and timely treatment modality. Platelet-rich plasma (PRP) injection has been proposed as an enticing treatment option, but there is no consensus regarding its effectiveness.

Purpose

To pool the available data and evaluate the evidence of the effect of PRP injections on Achilles tendinopathy.

Study Design

Systematic review; Level of evidence, 1.

Methods

This review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. CINAHL via EBSCOhost, Cochrane Library, and PubMed databases were searched for randomized controlled trials comparing PRP injection with nonoperative treatment, with the Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire score or maximal Achilles tendon (AT) thickness on ultrasound as outcome measures. Risk-of-bias assessment was performed of the included studies, and meta-analyses compared differences in outcome measures between PRP injection and control at the short-term (3-month), intermediate-term (6-month), and long-term (12-month) follow-ups.

Results

Of 409 publications, 6 publications (N = 422 patients with chronic midportion Achilles tendinopathy) were identified from the literature search. Risk-of-bias assessment revealed 2 studies were low risk, 1 was of some concern, and 3 were high risk of bias. Meta-analysis revealed no significant differences between PRP injection and control at any time point for both VISA-A score (short term: P = .29; intermediate term: P = .42; long term: P = .57) and maximal AT thickness (short term: P = .60; intermediate term: P = .20; long term: P = .55).

Conclusion

Our review demonstrated that although recent trends have shown an increasing popularity of PRP injection, no solid evidence has been established. The heterogenicity of the tendinopathy pathology and the PRP injection content and methodology should be controlled by better-designed clinical trials. Further research is needed before it should be recommended as a standard treatment.

Imaging features of soft-tissue infections

Skin and soft tissues are among the most common sites of infections. Infections can involve the superficial epidermis to deep muscles and bones. Most infections spread through contiguous structures, although hematogenous spread can occur in the setting of an immunocompromised state and with atypical infections. While clinical diagnosis of infections is possible, it often lacks specificity, necessitating the use of imaging for confirmation. Cross-sectional imaging with US, CT, and MRI is frequently performed not just for diagnosis, but to delineate the extent of infection and to aid in management. Nonetheless, the imaging features have considerable overlap, and as such, it is essential to integrate imaging features with clinical features for managing soft tissue infections. Radiologists must be aware of the imaging features of different infections and their mimics, as well as the pros and cons of each imaging technique to properly use them for appropriate clinical situations. In this review, we summarize the most recent evidence-based features of key soft tissue infections.

Sound touch elastography of Achilles tendons in patients with type 2 diabetes mellitus versus healthy adults

BACKGROUND

The studies of the effect of diabetes on the stiffness of Achilles tendon (AT) tissue remain inconclusive, we believe it is necessary to find a reliable method which can be used to detect the stiffness changes of the AT in the diabetic state. The objective of the present study was to investigate the effectiveness of sound touch elastography (STE) as a tool for detecting diabetic Achilles tendinopathy.

METHODS

We conducted a retrospective review of 180 participants, consisting of 82 patients with type 2 diabetes mellitus (T2DM) and 98 healthy adults, who had undergone AT ultrasonography. Young 's modulus (E) values of the distal, middle, and proximal segments of bilateral ATs of all participants were measured using STE technique. The E values of each AT segment between the case and control group were compared.

RESULTS

The E values of the three segments of ATs in T2DM patients were lower than the healthy controls (P < 0.05). In both groups, the E values of the distal segments were lower than those of the middle segments, and the latter were lower than those of the proximal segments (P < 0.05). The E value of each segment of AT was inversely related to FPG, HbA1c, and diabetes duration (P < 0.05). The best cut-off points for the E values of the three segments of the AT for detecting diabetic tendinopathy were 347.44 kPa (AUC, 0.779), 441.57 kPa (AUC, 0.692), and 484.35 kPa (AUC, 0.676), respectively.

CONCLUSION

STE can be used as a complementary diagnostic tool for the diagnosis of diabetic Achilles tendinopathy.

Emerging role of bone scintigraphy single-photon emission computed tomography/computed tomography in foot pain management

Foot and ankle joints being weight-bearing joints are commonly subjected to wear and tear and are prone to traumatic and other pathologies. Most of these foot and ankle pathologies present with pain. The diagnosis of pathology and localization of pain generators is difficult owing to the complex anatomy of the foot and similar clinical presentation. This makes the management of foot pain clinically challenging. Conventional anatomical imaging modalities are commonly employed for evaluation of any anatomical defect; however, these modalities often fail to describe the functional significance of the anatomical lesions, especially in presence of multiple lesions which is common in ankle and foot; however, hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) by virtue of its dual modalities, that is, highly sensitive functional imaging and highly specific anatomical imaging can serve as a problem-solving tool in patient management. This review attempts to describe the role of hybrid SPECT/CT in overcoming the limitation of conventional imaging and describes its potential application in the management of foot and ankle pain.

Bone Stress Injuries at the Ankle and Foot

Bone stress injuries (BSIs) are a frequent finding in athletes, particularly of the foot and ankle. A BSI is caused by recurring microtrauma to the cortical or trabecular bone exceeding the repair capacity of normal bone. The most frequent fractures at the ankle are low risk, characterized by a low risk for nonunion. These include the posteromedial tibia, the calcaneus, and the metatarsal diaphysis. High-risk stress fractures have a higher risk for nonunion and need more aggressive treatment. Examples are the medial malleolus, navicular bone, and the base of the second and fifth metatarsal bone.Imaging features depend on the primary involvement of cortical versus trabecular bone. Conventional radiographs may remain normal up to 2 to 3 weeks. For cortical bone, early signs of BSIs are a periosteal reaction or the "gray cortex sign," followed by cortical thickening and fracture line depiction. In trabecular bone, a sclerotic dense line may be seen. Magnetic resonance imaging enables early detection of BSIs and can differentiate between a stress reaction and a fracture. We review typical anamnestic/clinical findings, epidemiology and risk factors, imaging characteristics, and findings at typical locations of BSIs at the foot and ankle that may help guide treatment strategy and patient recovery.

Ankle Sprains in Athletes: Current Epidemiological, Clinical and Imaging Trends

Purpose

Ankle injuries are frequent sports injuries. Despite optimizing treatment strategies during recent years, the percentage of chronification following an ankle sprain remains high. The purpose of this review article is, to highlight current epidemiological, clinical and novel advanced cross-sectional imaging trends that may help to evaluate ankle sprain injuries.

Methods

Systematic PubMed literature research. Identification and review of studies (i) analyzing and describing ankle sprain and (ii) focusing on advanced cross-sectional imaging techniques at the ankle.

Results

The ankle is one of the most frequently injured body parts in sports. During the COVID-19 pandemic, there was a change in sporting behavior and sports injuries. Ankle sprains account for about 16-40% of the sports-related injuries. Novel cross-sectional imaging techniques, including Compressed Sensing MRI, 3D MRI, ankle MRI with traction or plantarflexion-supination, quantitative MRI, CT-like MRI, CT arthrography, weight-bearing cone beam CT, dual-energy CT, photon-counting CT, and projection-based metal artifact reduction CT may be introduced for detection and evaluation of specific pathologies after ankle injury. While simple ankle sprains are generally treated conservatively, unstable syndesmotic injuries may undergo stabilization using suture-button-fixation. Minced cartilage implantation is a novel cartilage repair technique for osteochondral defects at the ankle.

Conclusion

Applications and advantages of different cross-sectional imaging techniques at the ankle are highlighted. In a personalized approach, optimal imaging techniques may be chosen that best detect and delineate structural ankle injuries in athletes.

MR Imaging–Ultrasonography Correlation of Acute and Chronic Foot and Ankle Conditions

Foot and ankle injuries are common musculoskeletal disorders. In the acute setting, ligamentous injuries are most common, whereas fractures, osseous avulsion injuries, tendon and retinaculum tears, and osteochondral injuries are less common. The most common chronic and overuse injuries include osteochondral and articular cartilage defects, tendinopathies, stress fractures, impingement syndromes, and neuropathies. Common forefoot conditions include traumatic and stress fractures, metatarsophalangeal and plantar plate injuries and degenerations, intermittent bursitis, and perineural fibrosis. Ultrasonography is well-suited for evaluating superficial tendons, ligaments, and muscles. MR imaging is best for deeper-located soft tissue structures, articular cartilage, and cancellous bone.

Morphometric Analysis of Achilles Tendon Structure and Its Significance: A Cadaveric Study

INTRODUCTION

Achilles tendon is crucial for gait, and chronic Achilles tendinopathy can have a substantial impact on an individual's work and active involvement in physical or sports activity, and overall quality of life.

OBJECTIVES

This research was to determine the macroscopic and microscopic anatomy of Achilles tendons in cadavers.

MATERIALS AND METHODS

This experimental study was conducted in the Department of Anatomy, Saveetha Medical College, Thandalam, from March to August 2022. A total of 60 formalin-perfused cadavers (38 males and 22 females) were dissected to study their morphometry (length, width, thickness) and histology. The data was tabulated in MS excel and analyzed statistically using unpaired 't-test and one-way ANOVA in SPSS Software 17.0 (IBM Corp., Armonk, NY).

RESULTS

The mean length of the Achilles tendon was significantly higher in males than in females and similarly, the length on the right side was significantly higher than on the left side (p<0.005). The width and circumference were statistically higher in females than, males whereas, the histological features were similar in both males and females.

CONCLUSION

The better understanding of Achilles tendon morphometry in cadavers always aids in the diagnosis and surgical repair of tendinopathy, rupture, and degenerative change. The knowledge will be helpful for the surgeons during the repair and reconstruction of the injured tendon.

Aşil tendonu gerinim oranı ile mitral anulus kalsifikasyonu varlığı arasındaki ilişki

Amaç: Aşil tendonu (AT)- ultrasonografisi (US) ve gerinim elastografisi (SE) ile elde edilen AT- kalınlığı (T) ve AT- gerinim oranının (SR) mitral kapak kalsifikasyonlu (MAC) hastaları belirlemedeki önemini araştırmayı amaçladık. Gereç ve Yöntem: Çalışmaya ekokardiyografi sonrası MAC tanısı alan 100 hasta (65 kadın, 35 erkek ve ortalama yaş 64.7 ± 12.1) ve kardiyovasküler risk faktörü benzer olan 50 kontrol (32 kadın, 18 erkek ve ortalama yaş 63.2 ± 12.8) alındı. Laboratuvar incelemeler ve AT US yapıldı. AT-T ve AT-SR hesaplandı. Bulgular: MAC olan hastalarda AT-T ve AT-SR belirgin olarak yüksek olduğu bulundu. Logistic regresyon analizinde, AT-T ve AT-SR değerlerinin MAC olma riskini bağımsız olarak belirlediği bulundu. Bu analize göre AT-T (her 1 mm) ve AT-SR (her 0.1)’nin MAC olma riskini sırası ile %69.9 ve %12.7 oranlarında artırdığı saptandı. AT-T ve AT-SR değerlerinin MAC olan hastaları belirlemesi açısından ROC analizi yapıldığında, ROC eğri altında kalan alanın sırası ile 0.684 ve 0.819 belirlendi. Aynı analizde, AT-SR için sınır değer 1.25 olarak alındığında %94.1 sensitivite ve %76.2 spesivite ile MAC varlığını belirlediği tespit edildi. Sonuç: AT SE incelemesinde saptanan AT-SR, MAC olan hastaları önceden belirlemede kullanılabilecek basit, ucuz, tekrarlanabilir ve non-invaziv bir parametredir. Bu durum MAC ve AT-SR artışının benzer fizyopatolojik mekanizma ile meydana gelebilmesinin bir sonucu olabilir.

The Achilles Tendon: Imaging Diagnoses and Image-Guided Interventions-AJR Expert Panel Narrative Review

The Achilles tendon is commonly affected by both chronic repetitive overuse and traumatic injuries. Achilles tendon injuries can potentially affect any individual but have a particularly high incidence in professional athletes. Appropriate imaging evaluation and diagnosis are paramount to guiding appropriate management. In this AJR Expert Panel Narrative Review, we discuss the role of various imaging modalities (particularly ultrasound and MRI) in the assessment of Achilles tendon pathology, focusing on modalities' relative advantages and technical considerations. We describe the most common diagnoses affecting the Achilles tendon and adjacent structures, highlighting key imaging findings and providing representative examples. Various image-guided interventions that may be employed in the management of Achilles tendon pathology are also reviewed, including high-volume injection, tendon fenestration, prolotherapy, and corticosteroid injection. The limited evidence supporting such interventions are summarized, noting an overall paucity of large-scale studies showing benefit. Finally, a series of consensus statements by the panel on imaging and image-guided intervention for Achilles tendon pathology are provided.

Posterior Tibial Tendon Dislocation: A Case Report

Isolated posterior tibial tendon dislocation is a rare condition. Diagnosis can be challenging, especially in the acute clinical setting. Predisposing factors include shallow posterior tibial tendon groove and tear of the flexor retinaculum. We report the case of traumatic subluxation of the posterior tibial tendon, illustrating imaging findings and surgical technique. Posterior tibial tendon dislocation was detected using dynamic ultrasound, while magnetic resonance was essential for a comprehensive evaluation that included underlying predisposing anatomic abnormalities and associated pathologic conditions. Conservative treatment is often unsuccessful thus surgical approach was needed. Under ampliscopic guidance, a bone tunnel was created behind the retromalleolar groove. The posterior tibial tendon was located into the new groove and the retinaculum was re-attached and tightened by anchors and absorbable sutures at the anterior margin of the sulcus. At 12-month follow-up, the patient did not complain any residual pain and he was able to perform normal daily activities without any limitations and with no further tendon dislocations.

How to Report: Ankle MRI

Reporting ankle magnetic resonance imaging involves the assessment of multiple joints, tendons, and ligaments in several planes and numerous sequences. This article describes an approach using four anatomical categories (subcutaneous fat, bones and joints, tendons, and ligaments) to simplify and improve reporting efficiency. The main pathologies are covered, emphasizing the specific features to comment on, as well as suggesting terminology and phrases to use when reporting.

Retrocalcaneal Enthesophyte Resection With Functional Lengthening of the Achilles Tendon and Buried Knot Technique: A Case Series

Retrocalcaneal exostosis can be debilitating and in severe cases, surgical resection is indicated. Complications can arise from surgical resection of the exostosis and reattachment of the Achilles tendon, including irritation of the suture knot, recurrence of the bony prominence, and dehiscence. The use of a buried knot technique with functional lengthening of the Achilles tendon and gastroc-soleal muscle complex can minimize these complications. Complete detachment of the Achilles tendon allows for aggressive and thorough resection of the exostosis and functional lengthening with reattachment. The buried cruciate knot technique allows for firm reattachment with buried knots to prevent soft tissue irritation. A total of fourteen patients (14 limbs) underwent retrocalcaneal enthesophyte resection with functional Achilles tendon lengthening, (8/14) of which had difficultly wearing shoe gear, (10/14) had edema, and (2/14) had erythema preoperatively. Postoperatively, (11/14) of patients returned to full activities and sports, and (11/14) returned to normal shoe gear. Complications included (1/14) of patients with Achilles tendon avulsion and (3/14) of patients with surgical site dehiscence requiring revisional surgery. Overall, this technique helps prevent short-term complications and long-term recurrence due to the functional lengthening mitigating insertional forces on the Achilles tendon.

The anatomical variant of high soleus muscle may predispose to tendinopathy: a preliminary MR study

PURPOSE

This study aimed to examine the anatomic variations at the level of the distal soleus musculotendinous junction and the possible association between the length of the free tendon and the development of symptomatic Achilles tendinopathy.

METHODS

We retrospectively assessed 72 ankle MRI studies with findings of Achilles tendinopathy (study group, 26 females/46 males, mean age 52.6 ± 10.5 years, 30 right/42 left) and 72 ankle MRI studies with normal Achilles tendon (control group, 32 females/40 males, mean age 35.7 ± 13.7 years, 42 right/30 left side). We measured the distance from the lowest outline of the soleus myotendinous junction to the proximal outline of the Achilles tendon insertion (length of the free tendon, diameter a) and to the distal outline of the insertion (distance B). We also measured the maximum thickness of the free tendon (diameter c) and the distance between the levels of maximum thickness to the proximal outline of the Achilles tendon insertion (distance D). All measurements were assessed twice. Statistical analysis was performed using independent t test.

RESULTS

Distances A and B were significantly larger in tendinopathic tendons (59.7 and 83.4 mm, respectively) than normal Achilles tendons (38.5 and 60.8 mm, respectively) (p = 0.001). Mean distance C was larger in tendinopathic than normal tendons (11.2 versus 4.9 mm). Distances C and D were significantly larger in males than females. There was no significant difference in the measurements between sides.

CONCLUSION

There is wide anatomical variation in the length of the free Achilles tendon. Tendinopathy may be associated with the thicker free part of the Achilles tendon. The anatomical variant of the high soleus musculotendinous junction resulting in a longer free Achilles tendon may be a predisposing factor to the development of tendinopathy.

Sex Differences in the Morphological and Mechanical Properties of the Achilles Tendon

Background: Patients with Achilles tendon (AT) injuries are often engaged in sedentary work because of decreasing tendon vascularisation. Furthermore, men are more likely to be exposed to AT tendinosis or ruptures. These conditions are related to the morphological and mechanical properties of AT, but the mechanism remains unclear. This study aimed to investigate the effects of sex on the morphological and mechanical properties of the AT in inactive individuals. Methods: In total, 30 inactive healthy participants (15 male participants and 15 female participants) were recruited. The AT morphological properties (cross-sectional area, thickness, and length) were captured by using an ultrasound device. The AT force–elongation characteristics were determined during isometric plantarflexion with the ultrasonic videos. The AT stiffness was determined at 50%–100% maximum voluntary contraction force. The AT strain, stress, and hysteresis were calculated. Results: Male participants had 15% longer AT length, 31% larger AT cross-sectional area and 21% thicker AT than female participants (p < 0.05). The plantarflexion torque, peak AT force, peak AT stress, and AT stiffness were significantly greater in male participants than in female participants (p < 0.05). However, no significant sex-specific differences were observed in peak AT strain and hysteresis (p > 0.05). Conclusions: In physically inactive adults, the morphological properties of AT were superior in men but were exposed to higher stress conditions. Moreover, no significant sex-specific differences were observed in peak AT strain and hysteresis, indicating that the AT of males did not store and return elastic energy more efficiently than that of females. Thus, the mechanical properties of the AT should be maintained and/or improved through physical exercise.

Comparison Between Ultrasonography and Magnetic Resonance Imaging in Achilles Tendon

Purpose: This study aims was to compared the effectiveness of Magnetic Resonance Imaging (MRI) and Ultrasonography (US) imaging techniques in the diagnosis of tendon pathology. Method: The databases search of PubMed, Scopus, and Embase extracted 567 articles for a title and abstract review. After removing and evaluating, a total of 6 articles were collected. Results and conclusion: There are three views on the diagnosis of Achilles tendon (AT) by US and MRI: US has higher sensitivity and reliability than MRI; MRI is more effective than the US, and there is a similar diagnosis result between US and MRI. It may not be necessary to distinguish between the diagnostic role of US and MRI, since US and MRI tools can be used as effective means to provide valuable information for the diagnosis and treatment of AT.

Usefulness of Imaging Techniques in the Diagnosis of Selected Injuries and Lesions of the Canine Tarsus. A Review

Simple Summary

Tarsal joint lesions are uncommon in dogs but may lead to serious health problems. The most common diseases involving the tarsal joint are osteochondrosis, fractures and injuries of the Achilles tendon. The basis for the diagnosis of lesions in the tarsus is a thorough orthopedic examination, sometimes performed under sedation. Imaging modalities such as radiography, ultrasonography, magnetic resonance imaging or computed tomography can facilitate the detection and assessment of lesions in the canine tarsal joint. The aim of this paper is to characterize and compare the usefulness of imaging techniques available in veterinary medicine for the diagnosis and evaluation of lesions and injuries affecting the tarsal joint in dogs.

Abstract

Tarsus lesions are not common in dogs, but they can cause serious health problem. They can lead to permanent changes in the joint and, in dogs involved in canine sports, to exclusion from training. The most common diseases and injuries involving the tarsal joint are osteochondrosis, fractures and ruptures of the Achilles tendon. These conditions can be diagnosed primarily through accurate orthopedic examination, but even this may be insufficient for performing a proper diagnosis. Imaging modalities such as radiography, ultrasonography, magnetic resonance imaging or computed tomography can facilitate the detection and assessment of lesions in the canine tarsal joint. This review paper briefly presents some characteristics of the above-mentioned imaging techniques, offering a comparison of their utility in the diagnosis of lesions and injuries involving the canine tarsus.

Return to Play After Open Calcaneoplasty for Insertional Achilles Tendinopathy With Haglund Deformity in Competitive Professional Athletes

Background

Surgical treatment of insertional Achilles tendinopathy with Haglund deformity in highly competitive professional athletes has not been previously investigated.

Purpose

To assess clinical outcomes, including return to play (RTP), after surgical treatment of insertional Achilles tendinopathy in professional athletes.

Study Design

Case-control study; Level of evidence, 3.

Methods

This retrospective study included 20 professional athletes who were surgically treated for insertional Achilles tendinopathy and had at least 2 years of follow-up. An open longitudinal lateral approach was used for the operation, without violation of the Achilles tendon. Outcome evaluation included American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, subjective patient satisfaction, mean time of return to competition (RTC), and rate of RTP. We defined RTC as return to an official match for at least 1 minute and RTP rate as the percentage of patients who were able to participate in at least 2 full seasons. A subgroup analysis was performed to compare the RTP and no-RTP groups.

Results

The AOFAS score improved significantly from preoperatively to the final follow-up (from 65.1 to 88.4; P < .001), and 75% of the patients reported good to excellent satisfaction. The mean time of RTC was 7.45 months (range, 4-18 months), and the rate of RTP was 60%. The RTP group had a significantly lower mean body mass index than did the no-RTP group (22.03 vs 23.86, respectively; P = .005) and faster mean RTC (5.0 vs 11.1 months, respectively; P < .001).

Conclusion

Open calcaneoplasty for surgical treatment of insertional Achilles tendinopathy with Haglund deformity in highly competitive professional athletes should be approached cautiously. Our patients had a 7.5-month recovery period before return to their first official match, and only 60% of the patients returned to their sports activity and participated in at least 2 full seasons. Lower body mass index and a faster RTC after surgery were related to longer functional maintenance.

The Vienna morphological Achilles tendon score-VIMATS : Description, reproducibility and initial clinical results

OBJECTIVE

The purpose was to introduce the Vienna morphological Achilles tendon score (VIMATS), to evaluate its reproducibility and to assess its clinical application.

METHODS

In 38 patients a total number of 40 painful ATs and 20 volunteers were examined on a 3T magnetic resonance imaging (MRI) scanner using a standard MRI protocol. In 20 patients clinical scoring according to the Achilles tendon rupture score was available. Two observers independently assessed the thickness, continuity, signal intensity, and associated pathologies of the Achilles tendon (AT) according to the newly created VIMATS. Intraobserver and interobserver agreements were calculated and the clinical application of the VIMATS regarding its potential to differentiate between patients and volunteers was tested.

RESULTS

An analysis of the Intraclass correlation coefficient (ICC) yielded an excellent intraobserver (ICC 0.925) and interobserver agreement (ICC 0.946) for the total VIMAT score. A significant difference in total VIMATS was found between patients (47.6 ± StD 21.1 points) and volunteers (91.5 ± SD 10.9 points; p < 0.01) as well as a moderate correlation between morphological and clinical scoring (Pearson correlation 0.644).

CONCLUSION

The VIMAT score is the first MRI score for the semiquantitative morphological evaluation of AT injuries and was shown to be an easy, fast and reproducible tool for assessing injuries of the AT.

MRI of the Achilles tendon - a comprehensive pictorial review. Part two

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The abnormalities on MRI should be correlated with the clinical findings.

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Higher signal of the Achilles tendon is a common postoperative finding.

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The fluid signal within the Achilles tendon graft indicates a rupture.

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Postoperative complications of Haglund’s syndrome should be assessed on MRI.

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Elongation of the Achilles tendon is seen after surgical or conservative treatment.

The most common disorder affecting the Achilles tendon is midportion tendinopathy. A focal fluid signal indicates microtears, which may progress to partial and complete rupture. Assessment of Achilles tendon healing should be based on tendon morphology and tension rather than structural signal. After nonoperative management or surgical repair of the Achilles tendon, areas of fluid signal is pathologic because it indicates re-rupture. A higher signal in the postoperative Achilles tendon is a common finding and is present for a prolonged period following surgical intervention and needs to be interpreted alongside the clinical appearance.

The correlations between dimensions of the normal tendon and tendinopathy changed Achilles tendon in routine magnetic resonance imaging

This comparative study aimed to investigate how tendinopathy-related lesions change correlations in the dimensions of the Achilles tendon. Our experimental group included 74 patients. The mean age was 52.9 ± 10.4 years. The control group included 81 patients with a mean age was 35.2 ± 13.6 years, p < .001. The most significant difference in correlation was the thickness of the tendon and the midportion's width, which was more significant in the tendinopathy (r = .49 vs. r = .01, p < .001). The correlation was positive between width and length of the insertion but negative in normal tendons (r = .21 vs. r = − .23, p < .001). The correlation was between the midportions width in tendinopathy and the tendon's length but negative in the normal tendon (r = .16 vs. r = − .23, p < .001). The average thickness of the midportion in tendinopathy was 11.2 ± 3.3 mm, and 4.9 ± 0.5 mm in the control group, p < .001. The average width of the midportion and insertion was more extensive in the experimental group, 17.2 ± 3.1 mm vs. 14.7 ± 1.8 mm for the midportion and 31.0 ± 3.9 mm vs. 25.7 ± 3.0 mm for insertion, respectively, p < .001. The tendon's average length was longer in tendinopathy (83.5 ± 19.3 mm vs. 61.5 ± 14.4 mm, p < .001). The dimensions correlations in normal Achilles tendon and tendinopathic tendon differ significantly.

Flexor hallucis longus hypertrophy secondary to Achilles tendon tendinopathy: an MRI-based case-control study

PURPOSE

The purpose of this study was to outline an indirect sign of advanced Achilles tendinopathy on magnetic resonance imaging (MRI), based on the hypothesis that these patients would present with secondary hypertrophy of the flexor hallucis longus muscle (FHL).

METHODS

MRI scans of Achilles tendon were analyzed retrospectively in two cohorts. The study group consisted of consecutive patients presenting with clinical signs of Achilles tendinopathy and no previous surgeries, while the control group were patients that had an MRI due to other reasons and no signs of tendinopathy. Two parameters from two muscle bellies were measured and compared on axial MRI scans 4-5 cm above the ankle joint line at the level of greatest thickness: area and diameter of the triceps surae (TS) and of the FHL muscle. Ratios (FHL/TS) were calculated for area (Ar) and diameter (Dm) measurements. Interobserver agreement was analyzed. A receiver operating characteristic (ROC) curve was created for both ratios to assess potential cutoff points to differentiate between the groups.

RESULTS

A total of 60 patients for each study group were included. Both ratios Ar(FHL/TS) and Dm(FHL/TS) showed significant higher values in the tendinopathy group (p < 0.001). There were strong to very strong intraclass correlation coefficients (ICC = 0.75-0.93). A diameter ratio Dm (FHL/TS) of 2.0 or higher had a sensitivity of 49% and specificity of 90% for concomitant Achilles tendinopathy.

CONCLUSION

In our patient cohort, FHL hypertrophy was observed in patients with Achilles tendinopathy as a possible compensatory mechanism. Measuring a diameter ratio Dm(FHL/TS) of 2.0 or higher on an axial MRI, may be indicative as an indirect sign of functional deterioration of the Achilles tendon.

The Utility of SPECT/CT in Diagnosing Haglund Syndrome With Bone Scintigraphy

Haglund syndrome-the combination of Haglund's deformity, retrocalcaneal bursitis, and achilles tendinopathy-is a common cause of hind foot pain in adults; however, diagnosis on planar scintigraphy can be challenging. We present a case of Haglund syndrome and show the key role that SPECT/CT can play in its diagnosis.

Sonoelastographic Evaluation of the Achilles Tendon in Patients With Type 2 Diabetes Mellitus

Diabetic foot is one of the dreaded complications of diabetes mellitus (DM). Alterations of the Achilles tendon (AT) may contribute to development of foot ulcers in diabetic patients. We evaluated the sonoelastographic abnormalities of the AT in 61 healthy volunteers and 81 patients with type 2 DM. The patients were further divided into those with and without peripheral neuropathy (PN). The AT thickness was measured in the proximal, middle and distal portions. Alterations in echo pattern were noted. The patients were found to have thicker tendons than the healthy volunteers (p < 0.01). Alterations in the echo pattern of the AT were more common in patients compared with healthy volunteers (p < 0.01). The shear wave velocity in the distal one-third of the AT was measured using shear wave elasticity imaging. Mean shear wave velocity values obtained were lower in patients compared with healthy volunteers (p < 0.001). No significant difference was found in the sonoelastographic findings of the AT in patients with and without PN. We conclude that there is softening, thickening and alterations in echo pattern of the AT in the form of hypoechogenicity, loss of fibrillar pattern and calcification at insertion in patients with type 2 DM, and these alterations could occur independent of onset of PN.

Gaelic Sport Injuries

The Gaelic sports of hurling and football, native to Ireland, are increasing in popularity worldwide. The injury profile of these sports requires multidisciplinary management by sports physicians, orthopaedic surgeons, and musculoskeletal (MSK) radiologists, among others. Advances in imaging modalities and interventional techniques have aided the diagnosis and treatment of sport injuries. In this article, we review the literature and our own institutional experience to describe common injury patterns identified in Gaelic games athletes, their main imaging features and relevant therapeutic interventions. We discuss the increasing prevalence of imaging services at sporting events and the central role of MSK radiologists in sports injury management.

Magnetic resonance imaging of the ankle and foot

This article reviews the magnetic resonance imaging (MRI) findings of the normal anatomy and various pathologic conditions of the ankle and foot commonly encountered in clinical practice. The spectrum of entities discussed includes osseous and osteochondral injuries, ligamentous injuries, common traumatic and degenerative tendon pathology, abnormalities of transverse tarsal joint (Chopart) and tarsometatarsal joint (Lisfranc) complexes, pathological conditions affecting capsuloligamentous structures of the great toe and lesser toes, as well as pedal infection, with a focus on diabetic osteomyelitis and neuropathic osteoarthropathy.

Achilles Tendinosis Injuries-Tendinosis to Rupture (Getting the Athlete Back to Play)

Recreational athletes are susceptible to experiencing pain in the Achilles tendon, affecting their ability to complete daily activities. Achilles tendinosis is a degenerative process of the tendon without histologic or clinical signs of intratendinous inflammation, which can be categorized by location into insertional and noninsertional tendinosis. This condition is one that can be treated conservatively with great success or surgically for refractory cases. Currently, there is a lack of consensus regarding the best treatment options. This review aims to explore both conservative and operative treatment options for Achilles tendinopathy and Achilles tendon rupture.

Pseudo-tear appearance of the Achilles tendon on MR imaging in normal volunteers

PURPOSE

The aim of this study was to confirm our clinical observation that a pseudo-tear appearance of the Achilles tendon is commonly seen on MRI and is of no clinical relevance.

MATERIALS AND METHODS

Forty-one ankles were imaged on a 3 T MR system, and PD weighted images with fat saturation were obtained in three orthogonal planes (TR, 2969 ms; TE, 30 ms; NA, 2; slice thickness, 2.5 mm). Volunteer exclusion criteria were symptoms of Achilles tendon pathology (such as acute or chronic posterior heel pain), history of trauma or surgery of the Achilles tendon. Internal signal of the Achilles tendon on axial and sagittal images was assessed independently by two observers. Internal signal of the Achilles tendon was classified from homogenously dark to different degree of hyperintense signal, where 0 means no internal hyperintensity, 1-minimal hyperintensity, 2-moderate and 3-marked. Descriptive statistics were calculated. Correlation between the two readers was also assessed. Two fresh cadavers were used in this study, one specimen being sliced in the sagittal plane and one specimen being dissected by an experienced anatomist.

RESULTS

Twenty one volunteers (8 men, 13 women), mean age of 24.7 years (19-43 years) were included in the study. On sagittal images both raters appreciated any degree of hyperintense signal in 59% of tendons. On axial images any degree of hyperintensity was seen in almost half of the cases (46 vs. 49%). Minimal hyperintensities were seen most commonly. Cohen's kappa coefficient for sagittal images was 0.964 (almost perfect agreement); for axial images 0.764 (substantial agreement). The anatomical studies demonstrated that the Achilles tendon is made up of different components that are partially separated and twist around each other explaining the pseudo-tear appearance.

CONCLUSION

The Achilles tendon is frequently not homogenously dark in normal volunteers as would be expected. Hyperintense signal is common in the long and short axis and related to the underlying anatomical features.

Sonographic Evaluation of Subclinical Enthesopathy in Patients of Chronic Plaque Psoriasis

BACKGROUND

Psoriasis is associated with spondyloarthropathy in 10%-30% of cases. Enthesitis is major feature of psoriatic arthritis. Ultrasonography can detect subclinical entheseal abnormalities in psoriasis patients.

OBJECTIVES

To determine the prevalence of subclinical enthesopathy in psoriasis vulgaris using ultrasonography and evaluating its correlation with severity and duration of psoriasis.

MATERIALS AND METHODS

This study included 50 patients of psoriasis vulgaris and 50 healthy controls. Sonographic evaluation of six sites bilaterally (proximal plantar fascia, distal Achilles tendon, distal and proximal patellar ligaments, distal quadriceps, and brachial triceps tendons) were done in each subject. All Ultrasonographic findings were identified according to MASEI (Madrid sonography enthesitis index). Enthesopathy scores of patients and controls were compared and receiver operating characteristic curve was used to determine cut off value of MASEI, above which ultrasound enthesitis of clinical significance could be diagnosed.

RESULTS

31 (62%) psoriasis patients had subclinical enthesopathy of clinical significance as compared to only 5 (10%) of controls. Mean MASEI score between psoriasis cases and control was statistically different, 12.72 ± 7.55 (Mean ± SD) and (5.14 ± 4.69), respectively (P value 0.000001).The receiver operating characteristic curve established an ultrasound score of >11 as the best cut-off to differentiate between subject with enthesopathy of clinical significance from those with enthesopathy of unknown significance. No statistically significant correlation was found between the degree of enthesopathy (MASEI score) and duration and severity of the psoriasis.

CONCLUSION

Ultrasonography can effectively screen subclinical entheseal abnormalities in psoriasis patients.

T1- and T2*-Mapping for Assessment of Tendon Tissue Biophysical Properties: A Phantom MRI Study

OBJECTIVES

The aim of this study was to quantitatively assess changes in collagen structure using MR T1- and T2*-mapping in a novel controlled ex vivo tendon model setup.

MATERIALS AND METHODS

Twenty-four cadaveric bovine flexor tendons underwent MRI at 3 T before and after chemical modifications, representing mechanical degeneration and augmentation. Collagen degradation (COL), augmenting collagen fiber cross-linking (CXL), and a control (phosphate-buffered saline [PBS]) were examined in experimental groups, using histopathology as standard of reference. Variable echo-time and variable-flip angle gradient-echo sequences were used for T2*- and T1-mapping, respectively. Standard T1- and T2-weighted spin-echo sequences were acquired for visual assessment of tendon texture. Tendons were assessed subsequently for their biomechanical properties and compared with quantitative MRI analysis.

RESULTS

T1- and T2*-mapping was feasible and repeatable for untreated (mean, 545 milliseconds, 2.0 milliseconds) and treated tendons. Mean T1 and T2* values of COL, CXL, and PBS tendons were 1459, 934, and 1017 milliseconds, and 5.5, 3.6, and 2.5 milliseconds, respectively. T2* values were significantly different between enzymatically degraded tendons, cross-linked tendons, and controls, and were significantly correlated with mechanical tendon properties (r = -0.74, P < 0.01). T1 values and visual assessment could not differentiate CXL from PBS tendons. Photo-spectroscopy showed increased autofluorescence of cross-linked tendons, whereas histopathology verified degenerative lesions of enzymatically degraded tendons.

CONCLUSIONS

T2*-mapping has the potential to detect and quantify subtle changes in tendon collagen structure not visible on conventional clinical MRI. Tendon T2* values might serve as a biomarker for biochemical alterations associated with tendon pathology.

Modified Percutaneous Achilles Tendon Lengthening by Triple Hemisection for Achilles Tendon Contracture

Background

Both percutaneous Achilles tendon lengthening by triple hemisection and the traditional open Z-lengthening are effective methods for Achilles tendon contracture. This study aims to evaluate the efficacy and safety of this new therapeutic method, which is based on the percutaneous sliding technique with three hemi-cuts in the tendon, as compared with the traditional open Z-lengthening.

Methods

Retrospective analysis of the Achilles tendon contracture cases in our hospital between January 2010 and September 2016 was conducted. Twenty-five cases received percutaneous Achilles tendon lengthening (group A), and 30 patients who underwent open Z-lengthening during the same period were in the control group (group B). Operative time and hospital stay were statistically analyzed. Incision complication, equinus recurrence rate and Achilles tendon rupture morbidity were recorded. The function was assessed by American Orthopaedic Foot & Ankle Society (AOFAS) score. All cases in group A received Magnetic Resonance Imaging (MRI) of ankle preoperatively and in the follow-ups.

Results

The mean follow-up period was 42.04 months in group A and 61.7 months in group B. The entire operative time and the mean hospitalization days were lower in group A than in group B. No incision and infection complication occurred in group A. The infection rate in group B was 3.3%. Equinus recurrence rate was 4% in group A and the equinus recurrence rate in group B was 21.4%. In group A, the mean AOFAS score increased from 64 ± 10.16 points preoperatively to 96.08 ± 3.17 at final follow-up, while the score in group B increased from 63.48 ± 6.2 points to 85.4 ± 10.3. MRI showed continuity of the Achilles tendon and homogeneous signal in group A.

Conclusion

Modified surgery can significantly reduce the risk of Achilles tendon rupture, provide better balance in soft tissue strength between ankle dorsiflexion and ankle plantarflexion, helping to avoid recurrence of the deformity.

Injection with autologous conditioned serum has better clinical results than eccentric training for chronic Achilles tendinopathy

PURPOSE

Chronic Achilles tendinopathy is one of the most common causes of malfunction and pain, which can lead to a significant reduction of the quality of life. The hypothesis of this study argues that autologous conditioned serum (i.e. Orthokine) injections in chronic midportion Achilles tendinopathy have a better outcome than eccentric training.

METHODS

This study investigates, retrospectively, the effects of peritendinous autologous conditioned serum injections as compared to standard eccentric training in 50 patients with chronic Achilles tendinopathy between 2012 and 2015. Before injection or eccentric training and 6 weeks, 12 weeks and 6 months thereafter, the patients were assessed by means of the VISA-A-G score (Victorian Institute of Sport Assessment-Achilles questionnaire-German). An MRI was also performed before and 6 months after injection and eccentric training.

RESULTS

Both patient groups had statistically significant better VISA-A-G scores after injection or eccentric training compared to the baseline before injection (90 vs 40, respectively, P < 0.001) or eccentric training (81 vs 47, respectively, P < 0.001). Comparing the baseline corrected VISA-A-G scores, patients in the autologous-conditioned-serum-group had significantly higher changes in VISA-A-G scores than the eccentric-training-group after 12 weeks (40 vs 36, P = 0.018) and 6 months (50 vs 34, P = 0.034). Both patient groups had statistically significant (P < 0.001) reduction of tendon thickness (autologous conditioned serum: 0.32; eccentric training: 0.24) and length of bursa (autologous conditioned serum: 0.24; eccentric training: 0.21) as well as significant (P < 0.001) improvement of tendon quality in MRI (autologous conditioned serum: 14 vs 1; eccentric training: 14 vs 2). There were no statistical differences in MRI-findings between the two groups.

CONCLUSION

Both therapies led to improvement of MRI-findings, including reduction of tendon thickness and tendon quality. Autologous-conditioned-serum-injections show greater clinical long-term benefit as compared to eccentric training and, therefore, offers a good alternative to eccentric training.

LEVEL OF EVIDENCE

Therapeutic studies, Level III.

Minimally Invasive and Endoscopic Treatment of Haglund Syndrome

Haglund syndrome is a triad of posterosuperior calcaneal prominence (Haglund deformity), retrocalcaneal bursitis, and insertional Achilles tendinopathy. The sources of pain include the posterior calcaneal wall cartilage, retrocalcaneal and subcutaneous adventitial bursa, and the Achilles tendon. Resection of the posterosuperior calcaneal tubercle, bursectomy, excision of the Achilles tendon pathology, reattachment of the Achilles tendon, gastrocnemius aponeurotic recession, and flexor hallucis longus transfer have been proposed as surgical treatment options. All of them can be performed endoscopically or under minimally invasive approaches.

MRI Assessment of Degeneration of the Tendon in Achilles Tendon Ruptures

BACKGROUND

The extent of tendinosis along the entire tendon in Achilles tendon ruptures (ATRs) has not previously been assessed. MR images of acute ATRs were evaluated to assess this extent, even in areas distant from the rupture.

METHODS

Patients who had MR images for an ATR were reviewed. Each tendon was divided into a proximal, middle, and distal segment with the full tendon length defined as the length measured from the myotendinous junction to the insertion. The site of tendon rupture, presence of tendinosis and/or additional tearing, and largest anteroposterior (AP) diameter in the remaining segments were noted. In total, 45 MR iamges were included in our study.

RESULTS

The mean total tendon length was 9.93 cm, while the length from the insertion to the tear was 5.86 cm. Of the 45 ruptures, 20 (44.4%) were in the proximal third, 19 (42.2%) in the middle third, and 6 (13.3%) in the distal third. In all remaining segments where no ruptured tendon was observed, tendinosis was seen. Further, of the 90 segments of a tendon without rupture, 87 (96.7%) had an AP diameter greater than 6 mm. Of those 90 segments without rupture, 24 (26.7%) had a secondary partial-thickness tear in another third.

CONCLUSION

Tendinosis is a known precursor of an ATR that in the current study was not limited to the area of rupture. The finding of extensive tendon degeneration may have implications for the optimal surgical treatment.

LEVEL OF EVIDENCE

Level IV, case series.

[Injuries of ligaments and tendons of foot and ankle : What every radiologist should know]

Injuries of the ligaments and tendons of the ankle and foot are among the most common musculoskeletal injuries. A correct and precise description of the pathology and possible accompanying injuries is essential for treatment planning by trauma and orthopedic surgeons. While X‑ray is used to exclude fractures, ultrasound is a very useful tool to assess the ligaments and tendons. For the radiologist, magnetic resonance imaging (MRI) is invaluable regarding the correct assessment of (partial) ruptures, as well as for evaluating accompanying injuries. The aim of the present overview is to provide the most relevant facts for radiologists regarding injuries of ligaments and tendons of the ankle and foot. A description of expected MRI findings and possible pitfalls are presented. For each ligament complex or tendon, we review the anatomy, followed by relevant facts on biomechanics and typical findings in case of injury. The lateral and medial ligament complex, syndesmosis, spring ligament complex, and the Lisfranc ligament are shown in detail. The Achilles tendon and the peroneal tendons are also discussed.

Usability of Achilles tendon strain elastography for the diagnosis of coronary artery disease

PURPOSE

There are close relationships between major coronary artery disease (CAD) risk factors and Achilles tendon thickness (AT-T) and AT strain ratio (AT-SR). Our aim was to evaluate the diagnostic importance of AT-T and AT-SR as obtained by ultrasonography (USG) and strain elastography (SE) for predicting CAD.

MATERIALS AND METHODS

One hundred and eighty-four patients scheduled to undergo coronary angiography were included in the study. Achilles tendon USG (B-mode and SE) and laboratory tests were performed on all patients. The patients were divided into two groups, i.e., patients with and without CAD.

RESULTS

The patients with CAD (72.8%) were more likely to be male, exhibited higher frequencies of diabetes mellitus (DM) and hyperlipidemia, exhibited higher levels of basal creatinine and glucose, and had higher AT-T and AT-SR values (p < 0.05 for all). Age, DM, AT-T, and AT-SR independently predicted the probability of CAD in a logistic regression analysis (p < 0.05 for all). Age (each year), DM (presence), AT-T (each 1 mm), and AT-SR (each 0.1) increased the CAD risk by 3.4%, 2.9 times, 47.1%, and 16.0%, respectively. ROC analysis revealed AUCs of 0.665 and 0.730 for the AT-T and AT-SR values, respectively (p < 0.05). The AT-SR cutoff value of 1.2 predicted the presence of CAD with 75.4% sensitivity and 72.7% specificity.

CONCLUSIONS

AT-SR is a simple, inexpensive, noninvasive, reproducible, and objective parameter for the prediction of CAD. We think that AT-SR evaluation should become a part of conventional USG assessments in patients who are at a high risk of CAD.

The "Gastrocnemius-Achilles Tendon-Calcaneus Complex": Different Responses after Percutaneous versus Vulpius Achilles Tendon Lengthening in New Zealand White Rabbits

BACKGROUND

This study aimed to describe the clinical, radiological, biomechanical, electromyographic, and histoenzymologic modifications in the "Gastrocnemius-Achilles Tendon-Calcaneus complex" caused by percutaneous Achilles tendon lengthening (PATL) versus Vulpius Achilles tendon lengthening (VATL) in New Zealand White (NZW) rabbits.

MATERIALS AND METHODS

Eight female NZW rabbits were used at 7 months of age. Two rabbits were euthanized before surgery for anatomical dissection, three underwent PATL (two bilateral and one unilateral), and the three others underwent VATL (two bilateral and one unilateral). Clinical examination, biomechanics, electromyography, standard radiographs and magnetic resonance imaging (MRI), and histology and histoenzymology were assessed after surgery.

RESULTS

At the end of the experiment, the subjects showed good clinical status but different functional outcomes of surgery: rabbits submitted to PATL developed permanent limp and lost their capacity to jump compared to rabbits submitted to VATL which remained able to ambulate and jump normally. Standard radiographs and MRI showed that PATL led to significantly greater increase in dorsal or anterior flexion of the tibiotarsal angle (TT angle) compared to VATL, whereas electromyographic and histoenzymologic observations of muscle unit showed little or no variation between the two groups of operated rabbits.

CONCLUSIONS

Although PATL leads to greater improvement in dorsal or anterior flexion (TT angle) of the rabbit ankle compared to VATL, it has negative effects on functional outcome as it reduces the contractile capacity of the rabbit muscle unit, ultimately impairing the ability to ambulate and jump.

Partial mid-portion Achilles tear resulting in substantial improvement in pain and function in an amateur long-distance runner

This case presents symptom resolution for a long-distance runner with chronic Achilles tendinopathy (AT), following a partial tear of his Achilles tendon. The patient reported a sudden pain during a morning run, with preserved function. Three hours postinjury, he was reviewed in a musculoskeletal clinic. An ultrasound scan confirmed a partial Achilles tear, associated with significant Doppler activity. His index of AT severity The Victorian Institute of Sports Assessment - Achilles Questionnaire (VISA-A) 4 hours postinjury was markedly higher compared with 2 weeks preinjury, indicating reduced symptom severity. A follow-up scan 4 weeks postinjury showed minimal mid-portion swelling and no signs of the tear. His VISA-A score showed continued symptom improvement. This case represents resolution of tendinopathic symptomatology post partial Achilles tear. While the natural histories of AT and Achilles tears remain unknown, this case may indicate that alongside the known role of loading, inflammation may be a secondary mediator central to the successful resolution of AT pain.

The Calcaneal Crescent in Patients With and Without Plantar Fasciitis: An Ankle MRI Study

OBJECTIVE

The bundled, crescent-shaped trabeculae within the calcaneal tuberosity-which we term and refer to here as the "calcaneal crescent"-may represent a structural adaption to the prevailing forces. Given Wolff law, we hypothesized that the calcaneal crescent would be more robust in patients with plantar fasciitis, a syndrome in part characterized by overload of the Achilles tendon-calcaneal crescent-plantar fascia system, than in patients without plantar fasciitis.

MATERIALS AND METHODS

MR images of 37 patients (27 women and 10 men; mean age ± SD, 51 ± 13 years; mean body mass index [BMI, weight in kilograms divided by the square of height in meters], 26.8 ± 6.3) referred for workup of foot or ankle pain were retrospectively evaluated by two blinded readers in this study. Patients were assigned to two groups: group A, which was composed of 15 subjects without clinical signs or MRI findings of Achilles tendon-calcaneal crescent-plantar fascia system abnormalities, or group B, which was composed of 22 patients with findings of plantar fasciitis. The thickness and cross-sectional area (CSA) of the Achilles tendon, calcaneal crescent, and plantar fascia were measured on proton density (PD)-weighted MR images. The entire crescent volume was manually measured using OsiriX software on consecutive sagittal PD-weighted images. Additionally, contrast-to-noise ratio (CNR) as a surrogate marker for trabecular density and the mean thickness of the calcaneal crescent were determined on PD-weighted MR images. The groupwise difference in the morphologic measurements were evaluated using ANOVA with BMI as a covariate. Partial correlation was used to assess the relationships of measurements for the group with plantar fasciitis (group B). Intraclass correlation coefficient (ICC) statistics were performed.

RESULTS

Patients with plantar fasciitis had a greater CSA and volume of the calcaneal crescent and had lower CNR (i.e., denser trabeculae) than those without Achilles tendon-calcaneal crescent-plantar fascia system abnormalities (CSA, 100.2 vs 73.7 mm², p = 0.019; volume, 3.06 vs 1.99 cm³, p = 0.006; CNR, -28.40 vs -38.10, p = 0.009). Interreader agreement was excellent (ICC = 0.85-0.99).

CONCLUSION

In patients with plantar fasciitis, the calcaneal crescent is enlarged compared with those without abnormalities of the Achilles tendon-calcaneal crescent-plantar fascia system. An enlarged and trabeculae-rich calcaneal crescent may potentially indicate that abnormally increased forces are being exerted onto the Achilles tendon-calcaneal crescent-plantar fascia system.

Diffusion tensor imaging of human Achilles tendon by stimulated echo readout-segmented EPI (ste-RS-EPI)

PURPOSE

Healing, regeneration, and remodeling of the injured Achilles tendon are associated with notable changes in tendon architecture. However, assessing Achilles microstructural properties with conventional diffusion tension imaging (DTI) remains a challenge because of very short T₂ / <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msubsup><mml:mi>T</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo></mml:msubsup> </mml:mrow> </mml:math> values of the tendon. Hence, the objective of this study was to develop a novel Achilles tendon DTI protocol for a non-invasive investigation of the changes of microstructural integrity in tendinopathy.

METHODS

A novel stimulated echo readout-segmented EPI (ste-RS-EPI) DTI sequence was proposed to achieve a TE of ∼14-20 ms for typical b-values of 400-800 s/mm² on clinical 3T MRI scanners. To further boost tendon MR signal, the Achilles was positioned at the magic angle (∼55 °) with respect to the scanner B₀ field. The sensitivity of the developed protocol was evaluated in 19 healthy participants and 6 patients with clinically confirmed tendinopathy.

RESULTS

Compared to spin echo RS-EPI DTI protocol, ste-RS-EPI provided an ∼100-200% increase in Achilles MR signal. Tendinopathic Achilles demonstrated a high degree of microstructural disruption based on DTI tractography analysis, with significantly lower (P < 0.05) axial diffusivity (1.20 ± 0.19 vs. 1.39 ± 0.10 × 10^-3 mm² /s), radial diffusivity (0.72 ± 0.11 vs. 0.81 ± 0.08 × 10^-3 mm² /s), and mean diffusivity (0.87 ± 0.14 vs. 1.00 ± 0.07 × 10^-3 mm² /s), but no significant difference in fractional anisotropy (0.38 ± 0.04 vs. 0.38 ± 0.05; P = 0.86).

CONCLUSION

Achilles tendon ste-RS-EPI DTI can non-invasively detect the tendinopathy-induced changes to microstructural integrity, consistent with the disruption of collagen arrangement and increased cellularity. This study demonstrated the robustness and sensitivity of the proposed protocol in Achilles tendinopathy.

Label-free photoacoustic microscopy for in-vivo tendon imaging using a fiber-based pulse laser

Tendons are tough, flexible, and ubiquitous tissues that connect muscle to bone. Tendon injuries are a common musculoskeletal injury, which affect 7% of all patients and are involved in up to 50% of sports-related injuries in the United States. Various imaging modalities are used to evaluate tendons, and both magnetic resonance imaging and sonography are used clinically to evaluate tendons with non-invasive and non-ionizing radiation. However, these modalities cannot provide 3-dimensional (3D) structural images and are limited by angle dependency. In addition, anisotropy is an artifact that is unique to the musculoskeletal system. Thus, great care should be taken during tendon imaging. The present study evaluated a functional photoacoustic microscopy system for in-vivo tendon imaging without labeling. Tendons have a higher density of type 1 collagen in a cross-linked triple-helical formation (65–80% dry-weight collagen and 1–2% elastin in a proteoglycan-water matrix) than other tissues, which provides clear endogenous absorption contrast in the near-infrared spectrum. Therefore, photoacoustic imaging with a high sensitivity to absorption contrast is a powerful tool for label-free imaging of tendons. A pulsed near-infrared fiber-based laser with a centered wavelength of 780 nm was used for the imaging, and this system successfully provided a 3D image of mouse tendons with a wide field of view (5 × 5 mm²).

MR Imaging of the Achilles Tendon after Surgical Repair

Achilles tendon tear is common and increasingly frequent. Magnetic resonance imaging (MRI) is the modality of choice for radiological evaluation. It is accurate to assess the status and integrity of the tendon with well documented features. In this article, the MR findings of a normal Achilles tendon as well as common diseases like insertional and noninsertional tendinosis, chronic tendinosis with marked lengthening, tendon rupture are illustrated. After a torn Achilles tendon receives surgical repair, it undergoes different stages of healing process including inflammatory, reparative and remodeling phases. Acute scar tissue in the surgical bed may share similar MR features of tendon re-rupture especially in the early healing phase because both are T2W hyperintense. The size of the gap may even appear larger than expected on T2W images possibly due to tendon remodeling. Understanding of the healing process in post-operative period may prevent overestimation of tendon gap and misdiagnosis of re-tear. We describe the MR features of the post-operative changes with serial studies in different months after surgery. The MR findings with the highlights of the expected sequential changes in normal healing process are illustrated in different cases. A case with surgical repair on a partial tear of Achilles tendon is also included.

Imaging Techniques and Indications

This article evaluates the utility of radiography, ultrasonography, and MRI in diagnosing Achilles tendon injuries. It reviews the pertinent anatomy of the Achilles and associated structures, and signs of disorder with each imaging technique. The economics of use ultrasonography and MRI are discussed. They should serve as complementary diagnostic tools, with ultrasonography the first choice because of its ease of use, ability to view dynamic function, and cost. However, clinical examination is often best for diagnosis; MRI and ultrasonography often should be considered only when the diagnosis is confounding or a patient does not respond to recommended conservative care.

Acute Achilles Tendon Rupture: Clinical Evaluation, Conservative Management, and Early Active Rehabilitation

The Achilles tendon (AT) is the strongest, largest, and most commonly ruptured tendon in the human body. Physical examination provides high sensitivity and specificity. Imaging studies are not recommended unless there are equivocal findings in the physical examination. Recent studies have shown that the risk of re-rupture is negated with implementation of functional rehabilitation protocols. Heterogeneity in study design makes conclusions on the specifics of functional rehabilitation protocols difficult; however, it is clear that early weight bearing and early controlled mobilization lead to better patient outcome and satisfaction in both surgically and conservatively treated populations.

MR imaging as a problem solving tool in posterior ankle pain: A review

Posterior ankle pain is a cause of chronic pain and disability, afflicting a wide range of individuals. While proper identification of the cause is essential for timely and adequate treatment, identifying the cause and excluding mimickers is often challenging for the physician due to the complex nature of the joint. In addition, pathology that can cause posterior ankle pain may occur on their own or in co-existence. Clinical conditions that can present as posterior ankle pain include: posterior ankle impingement, Achilles tendon pathology, medial flexor tendon pathology, peroneal pathology, retrocalcaneal bursitis, posterior subtalar tarsal coalition, sinus tarsi, and tarsal tunnel syndrome. In this review we introduce current concepts of pathophysiology in the main conditions involved in posterior ankle pain, and review the role of MR in the diagnosis and management of each condition. When pathology can be detected earlier and with more specificity, appropriate and time-sensitive treatment can be commenced, thus improving clinical outcomes.