Achilles tendon: MR imaging at 1.5 T

Thirty magnetic resonance (MR) examinations of the Achilles tendon were performed: 20 from patients without suspected tendon abnormalities; ten from patients with suspected tendon abnormalities. The appearance of the normal Achilles tendon is hypointense and flattened. Partial tears appeared as high-signal intratendinous collections, complete acute ruptures appeared as tendinous discontinuity, and uncomplicated surgical repairs appeared as areas of tendinous continuity with inhomogeneous signal in the operative site. Chronic tendinitis appeared as a diffuse thickening of the tendon. MR imaging of the Achilles tendon at 1.5 T enabled the determination of the degree of tendinous continuity, which may help with diagnosis, treatment, and the pacing of rehabilitation.     

MR imaging of the Achilles tendon: overlap of findings in symptomatic and asymptomatic individuals

Objective: To differentiate MR imaging characteristics of symptomatic as compared with asymptomatic Achilles tendons. Design: 1.5 T MR images of 94 feet (88 patients) with ”abnormal” MR examinations were retrospectively evaluated and clinically correlated. Two masked, independent observers systematically evaluated for intratendon T2 signal, tendon thickness, presence of peritendonitis, retrocalcaneal bursal fluid volume, pre-Achilles edema, bone marrow edema at the Achilles insertion, and tears (interstitial, partial, complete). These findings were correlated with symptoms (onset and duration) and physical examination results (tenderness, palpable defects, increased angle of resting dorsiflexion). Results: Of the 94 ankles, 64 ankles (32 females, 29 males) were clinically symptomatic. No relationship between Achilles tendon disorders and age or gender was identified. Asymptomatic Achilles tendons frequently demonstrated mild increased intratendon signal (21/30), 0.747 cm average tendon thickness, peritendonitis (11/30), pre-Achilles edema (12/30), and 0.104 ml average retrocalcaneal bursal fluid volume. Symptomatic patients had thicker tendons (0.877 cm), greater retrocalcaneal fluid volume (0.278 ml), more frequent tears (23/64), a similar frequency of peritendonitis (22/64) but less frequent pre-Achilles edema (18/64). Sixty-four percent of the Achilles tendon tears were interstitial. Except for two interstitial tears in control patients, the majority of Achilles tears were in symptomatic patients (14/16). Only symptomatic tendons demonstrated partial or complete tendon tears. In addition, calcaneal edema was found almost exclusively in actively symptomatic patients. Thicker tendons were associated more often with chronic symptoms and with tears. When present in symptomatic patients, peritendonitis was usually associated with acute symptoms. The presence of pre-Achilles edema, however, did not distinguish acute from chronic disorders. Conclusion: There is significant overlap of MR findings in symptomatic and asymptomatic Achilles tendons. Furthermore, there is apparently a spectrum of disease in symptomatic tendons ranging from subtle intratendinous and peritendinous signal to partial and complete tendon tear. Received: 17 March 2000 Revision requested: 26 May 2000 Revision received: 19 July 2000 Accepted: 19 July 2000     

High association between accessory soleus muscle and Achilles tendonopathy

Objective  This study investigated the association between accessory soleus muscle and abnormalities of the Achilles tendon. Materials and methods  The authors reviewed 15 consecutive cases with a diagnosis of accessory soleus muscle from a computerized database of ankle magnetic resonance (MR) examinations reported between January 1998 and January 2007. On review, two cases were eliminated because of an incorrect initial diagnosis: One patient had a low lying soleus attachment to the Achilles tendon, while the other had a prominent flexor hallucis longus tendon partially obliterating Kager’s fat. The remaining 13 cases with accessory soleus muscles were evaluated for Achilles tendon abnormalities. Results  There were 13 cases of accessory soleus muscles in 11 patients; two patients had bilateral accessory soleus muscles (the only study patients with bilateral MR examinations in our sample). There were five male and six female patients ranging from 15 to 81 years of age (mean 48). There were nine cases (69.2%) in which Achilles tendonopathy was associated with accessory soleus muscle, including tendonopathy of each Achilles tendon in the two patients with bilateral accessory muscles. Conclusion  In our small patient population, there was a high association between accessory soleus muscle and Achilles tendonopathy.     

Posteromedial tibial plateau injury including avulsion fracture of the semimembranous tendon insertion site: ancillary sign of anterior cruciate ligament tear at MR imaging.

PURPOSE: To evaluate posteromedial tibial plateau injuries of or about the semimembranous tendon insertion site and their association with anterior cruciate ligament (ACL) tears on magnetic resonance (MR) images. MATERIALS AND METHODS: A retrospective study of MR images and conventional radiographs was performed in 10 patients with posteromedial tibial plateau injuries, including avulsion fractures of the semimembranous tendon insertion site. Associated abnormalities were analyzed, including ACL tears, medial meniscal tears, and other lateral femorotibial compartment injuries. Findings from the clinical history and physical examination were correlated with radiographic and MR imaging findings. Nine patients had arthroscopically or surgically documented ACL tears. RESULTS: All 10 patients had ACL tears at MR imaging. Five patients had posteromedial tibial plateau fractures: Four had avulsion fractures of the tendon insertion site, and one had a fracture lateral to the site. Five patients had posteromedial tibial plateau bruises: Two had bruises at the tendon insertion site. Five patients had tears of the posterior horn of the medial meniscus. Two patients had posterior meniscocapsular separations. Three patients showed evidence of the O'Donoghue triad. Six patients had bruises of the lateral tibial plateau and of the lateral femoral condyle. CONCLUSION: There appears to be an association between posteromedial tibial plateau injuries and ACL tears. Posteromedial tibial plateau injuries may be predictive of ACL status.     

Repair of Achilles tendon ruptures with a polylactic acid implant: assessment with MR imaging

An investigational tendon repair device composed of a polymer of lactic acid (PLA) is currently undergoing multicenter clinical trials for use in repairing rupture of the Achilles tendon. The advantages of the PLA device include high tensile strength and the induction of a rapid proliferative tissue response resulting in a shorter rehabilitation period than with conventional surgical repair. We reviewed 16 MR examinations performed in 10 patients 3-35 months after repair to characterize the MR appearance. All 16 T1-weighted sagittal images revealed a thickened fusiform tendon with streaks of moderate signal within the tendon corresponding to the PLA device and its surrounding collagenogenic response. The double-echo T2-weighted axial images at the mid tendon level demonstrated progressive changes in the signal pattern of the central portion of the tendon that reflected the maturation of the healing tendon. All tendons repaired with PLA implants were uniformly hypertrophied relative to the contralateral normal side because of the induced proliferative collagenogenic ingrowth. Two follow-up MR examinations were performed in six patients and showed mean reductions in tendon caliber of 24% and 30% at the mid and inferior levels. MR imaging of the Achilles tendon repaired with PLA implants shows a diffusely thickened tendon with streaks of signal within the tendon that distinguish it from tendons repaired by conventional techniques.     

Tendon involvement in pedal infection: MR analysis of frequency,distribution, and spread of infection

OBJECTIVE: The objective of our study was to evaluate the frequency, distribution, and extent of tendon involvement in patients with pedal infections. MATERIALS AND METHODS: Contrast-enhanced MR imaging examinations of 159 infected feet performed at 1.5 T were reviewed by two musculoskeletal radiologists for the presence and location of tendon infection (peritendinous enhancement contiguous to an adjacent ulcer or cellulitis) and for the spread of infection along tendons, which was defined as peritendinous contrast enhancement extending more than 2 cm beyond surrounding cellulitis. The study group was composed of 156 consecutive patients, 82.7% of whom had diabetes; all patients underwent subsequent surgical treatment. Results of MR evaluations were compared with the patients' charts and surgical reports. RESULTS: Of the 129 MR examinations showing an infection in the forefoot, MR evidence of tendon involvement in the infection was observed in 56 MR examinations (43%). The sum of involved tendons per ray was as follows: first ray (flexor tendon, n = 19; extensor tendon, n = 13), second (flexor tendon, n = 12; extensor tendon, n = 7), third (flexor tendon, n = 5; extensor tendon, n = 4), fourth (flexor tendon, n = 5; extensor tendon, n = 1), and fifth (flexor tendon, n = 11; extensor tendon, n = 6). Of the 32 MR examinations showing infection in the hindfoot, 14 examinations (44%) showed evidence of tendon involvement, most frequently of the distal Achilles tendon (n = 7). MR evidence of the spread of infection along a tendon was seen in 12 examinations, always with proximal spread of infection; and infection led to the development of an abscess in the central plantar compartment in three patients. Intraoperative evidence of a tendon infection was documented in 11 patients. The surgical procedure was altered because of the tendon infection in six patients. CONCLUSION: MR evidence of tendon infection is present in approximately half the patients who require surgery for pedal infection. Evidence of spread of the infection along tendons is seen infrequently on MR imaging. Detection of a tendon infection could influence surgical therapy.     

MR imaging of overuse injuries of the Achilles tendon

OBJECTIVE: This study was conducted to illustrate and classify the abnormalities found on high-resolution MR imaging of symptomatic Achilles tendons in athletic adult patients. SUBJECTS AND METHODS: One hundred patients with 118 painful Achilles tendons were imaged with a 1.5-T magnet. The tendon, peritendinous tissues, tendon insertion, and musculotendinous junction were examined on MR imaging. Twenty-eight patients underwent surgery, and histopathologic samples were taken in 13. Long-term follow-up was performed, on average, 3.4 years after MR imaging. RESULTS: Of 118 painful Achilles tendons, abnormalities were detected in 111. These were in the tendon (n = 90), surrounding structures, or both. Fifty-four tendons had a focal area of increased intratendinous signal, best detected on axial high-resolution T1-weighted gradient-echo MR imaging. Histopathology confirmed abnormal tendon structure. Of the 21 surgically proven foci of tendinosis, 20 were revealed on MR imaging. At the level of the insertion, changes were found in the tendon in 15%, in the retrocalcaneal bursa in 19%, and in the calcaneal bone marrow in 8% of the studies. Abnormalities in peritendinous soft tissues were detected in 67%. More than one type of abnormality was found in 64% of the studies. CONCLUSION: Lesions in the Achilles tendon and in the peritendinous structures can have similar clinical presentation. MR imaging detects and characterizes these changes. A more specific diagnosis and prognosis can be made with the use of MR imaging than with clinical examination alone.     

MR imaging of the tendons of the foot and ankle

Hindfoot pain from tendon pathology is common and seen in a wide range of patients from young athletes to older sedentary individuals. Magnetic resonance (MR) is an excellent technique for imaging tendons and for identifying injuries that can be treated with surgery. MR also demonstrates the presence of bone marrow edema, which is a cause of pain and often a marker for adjacent tendon injury. Finally, MR can reveal other etiologies that cause similar hindfoot pain, such as osteochondral injuries and impingement. In this article, we review the normal MR appearance of the ankle tendons and tendon sheath fluid. MR protocols for imaging the various ankle tendon groups are presented. We discuss the MR appearance of tendon pathology, including tendonosis/ tendinopathy, tenosynovitis and peritendonosis, partial and complete tears, subluxation and dislocation, and entrapment. The Achilles, medial, lateral, and anterior tendon groups are discussed separately so as to focus on the MR appearance specific to each region of the ankle.     

外伤性跟腱撕裂的MRI诊断

目的：评价磁共振(MRI)对外伤性跟腱撕裂的诊断价值。方法：收集经删检查并由手术证实的外伤性跟腱撕裂患者10例，回顾、分析其MRI表现。结果：10例患者均诊断正确(敏感性100％，特异性100％)。其中完全性撕裂8例，不完全性撕裂2例；撕裂发生在跟腱中上段2例、跟腱中段7例、跟腱下段1例；MRI主要表现为肌腱增粗10例，肌腱内信号增高10例，宽径／前后径比值缩小8例，肌腱连续性中断9例，断端分离、肌腱缩短3例。跟腱周围软组织肿胀及积液9例。结论：MRI能够直接显示跟腱的形态及其内部结构．对跟腱撕裂的术前诊断具有很高的敏感件和特异性．     

Magnetic resonance imaging of muscle injury

To further evaluate the role of magnetic resonance (MR) imaging in diagnosing and managing muscle injuries, eight patients with muscle pain or palpable masses were imaged. MR findings were correlated with clinical follow-up data. Increased signal was noted on T2-weighted images in torn and overused muscles. One extensively scarred muscle required surgical biopsy to exclude a fibrous tumor. Three partial muscle tears were treated conservatively. One complete musculotendinous junction tear required tendon transfer. MR studies noninvasively identified and staged various muscle injuries, thereby influencing management.     

Imaging of athletic injuries to the ankle and foot

Conventional radiographs in conjunction with clinical examination remains the primary method for evaluating the acute athletic injury. In most cases, suspected acute tendon and ligament injuries are initially treated based on physical examination. Magnetic resonance (MR) imaging, with its multiplanar capability and superb soft tissue contrast, is quickly becoming the method of choice for evaluating chronic foot and ankle pain and further defining the extent of tendon and ligament injuries. This article reviews the common acute and chronic (overuse) foot and ankle athletic injuries with an emphasis on imaging characteristics.     

Dynamic contrast-enhanced mr imaging and histopathology in chronic achilles tendinosis. A longitudinal MR study of 15 patients

Purpose: To evaluate the value of dynamic contrast-enhanced MR imaging (DEMRI) and its correlation to symptoms and histopathology in chronic Achilles tendinosis.Material and Methods: Fifteen patients with severe symptoms underwent DEMRI preoperatively and 2 years postoperatively. US-guided core biopsies of tendinosis tissue were obtained preoperatively and the specimens were analyzed using a semiquantitative protocol. DEMRI was evaluated by calculating the area under curve (AUC) of signal alteration and the static MR by a semiquantitative grading scale. A questionnaire and clinical examination evaluated the clinical outcome.Results: Early contrast enhancement (first 72 s) was seen in DEMRI at tendon lesions of the symptomatic Achilles tendons with a significant difference to asymptomatic contralateral tendon that revealed no or mild enhancement. Increased severity of tendon pathology (including fiber structure abnormality, increased vascularity, rounding of nuclei and increased amount of glycosaminoglycans) was correlated to both dynamic and static signal enhancement. Two years following surgical treatment, the signal alterations showed regression of early contrast enhancement (AUC decreased from 9 preoperatively to 2 postoperatively). The clinical outcome was as follows: 8 patients excellent, 4 good, 2 fair and 1 poor.Conclusion: Patients with chronic painful achillodynia showed an early contrast-agent enhancement corresponding to the tendon lesion. Increased enhancement correlated to increased severity of tendon histopathology and patient symptoms. Two years after surgical treatment the contrast-agent enhancement decreased.     

The ultrasonographic appearance of the ruptured Achilles tendon during healing: a longitudinal evaluation of surgical and nonsurgical treatment,with comparisons to MRI appearance

This prospective, randomized trial compared healing characteristics of the Achilles tendon after surgical and nonsurgical treatment for complete rupture of the Achilles tendon. Fifty-eight patients were examined by ultrasonography after 6, 12, and 24 months and by magnetic resonance imaging after 12 months. A standardized protocol was used, and the outcome was correlated with clinical findings. Common findings 1 year after the injury were tendon thickening and moderate heterogeneity of the tendon. Peritendinous reactions, edema, and defects were present only in a minority of patients. There were no significant differences between the treatment groups in any of the evaluated parameters apart from the gliding function of the tendon, which was significantly less in the surgically treated group than in the nonsurgically treated group. No correlations were found between the radiological findings and the clinical parameters, such as muscle strength, endurance, and range of motion. We conclude that the roles of ultrasonography and magnetic resonance imaging during the healing process after Achilles tendon rupture are limited, due to a weak correlation with clinical findings.     

Magnetic resonance signal, rather than tendon volume, correlates to pain and functional impairment in chronic Achilles tendinopathy

PURPOSE: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment. MATERIAL AND METHODS: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37-71 years). All patients suffered from pain in the mid-portion of the Achilles tendon. Intratendinous signal was calculated from five different sagittal sequences, using a computerized 3D seed-growing technique. Pain and functional impairment were evaluated using a questionnaire completed by patients. RESULTS: Severity of pain and functional impairment correlated to increased mean intratendinous signal in the painful tendon in all MR sequences (P < 0.05, median r = 0.38, range 0.28-0.43 for pain; P < 0.05, median r = 0.48, range 0.29-0.49 for functional impairment). However, tendon volume did not correlate to pain or functional impairment (P > 0.05). Difference in mean intratendinous signal between symptomatic and contralateral asymptomatic tendons was highly significant in all sequences (P < 0.05) except on T2-weighted images (P = 0.6). CONCLUSION: Severity of pain and disability correlated to increased MR signal rather than to tendon volume in patients with unilateral mid-portion chronic Achilles tendinopathy.     

MRI在跟腱撕裂的诊断价值

目的：探讨不同程度跟腱撕裂的MRI表现的具体特点,评估MRI在跟腱损伤病例中的诊断价值。方法：本院自2007年8月-2009年10月MRI共诊断跟腱损伤11例,所有患者均行MRI常规TSE序列轴位、矢状、冠状位扫描,并追加矢状SPIR序列。结果：全部病例均显示相应跟腱撕裂MRI表现,其中完全撕裂4例,部分撕裂7例,表现为跟腱周围及腱旁脂肪垫积液、跟腱形态的改变、跟腱信号异常以及在完全性撕裂中显示缺口的范围及大小。结论：利用MRI诊断跟腱撕裂,可以精确判定其撕裂程度、范围以及是否合并骨髓水肿。     

Painful conditions in the Achilles tendon region: a common problem in middle-aged competitive badminton players

Overuse injuries are the most frequent type in badminton, generally localized in the legs. An earlier study found 32% of young Swedish elite badminton players to have experienced disabling pain in the Achilles tendon region during the previous 5 years. The present investigation examined the prevalence and characteristics of painful conditions in the Achilles tendon region in 32 middle-aged competitive badminton players by means of questionnaire and physiotherapist's examination. Pain in the Achilles tendon region was reported by 44%, either presently or during the past 5 years, generally localized in the middle portion of the tendon. Symptoms had lasted 2 weeks-1 year (96 days). On the competition days 22% of the reported pain currently in the region. Age was found to be correlated to Achilles tendon pain, but there was no relationship between symptoms of pain and body mass index, gender, training quantity, or years of playing badminton. In conclusion, Achilles tendon pain seems to be relatively common among Swedish middle-aged competitive badminton players, particularly in the older ones.     

Conservative treatment of a partial Achilles tendon rupture with an intratendinous lesion

The Achilles tendon is a common site of acute and oversuse injuries in runners. A case is described here in which the diagnosis of a post-traumatic intratendinous lesion was based on clinical examination and magnetic resonance imaging (MRI), and where conservative treatment was given. After a 6 months follow-up, symptoms as well as the MRI verified that intra-tendinous structural abnormalities had disappeared. This case report demonstrates that conservative treatment may be sufficient to cure Achilles injury with severe structural changes inside the tendon.     

Range of motion,muscle torque and training habits in runners with and without Achilles tendon problems

Achilles tendon injuries are common in runners. The aim of the present study was to analyse the training programme, any Achilles tendon problems, muscle eightness and range of motion of the ankle joint, and concentric and eccentric musle torques of the calf muscles in middle-distance runners with and without Achilles tendon problems. Eighty-three middle-distance runners answered a questionnaire on their sports background, training habits and any injuries. Thirty-four percent had suffered from some type of problem relating to the Achilles tendon. Ten of the athletes who had suffered from Achilles tendon problems and ten who had never had any Achilles tendon trouble were randomly selected. These 20 runners underwent a clinical examination. The range of motion of the ankle joint was recorded objectively by a hydraulic and computerised isokinetic dynamometer by measuring resistance to passive motion. Concentric and eccentric muscle torques of the gastrocnemius-soleus complex were recorded. The runners with Achilles tendon problems had trained for significantly more years and covered significantly longer distances per weck than runners without Achilles tendon problems. There were no significant differences in other training methods or in best results over 800 m and 1500 m. Runners with Achilles tendon problems had a significantly lower range of motion of the ankle joint. They also had significantly lower eccentric torques of the gastroenemius-soleus complex, but no differences in concentric torques were found between the groups.     

MR imaging of patellar retinacular ligament injuries

Seventeen patients with patellar retinacular ligament injuries were evaluated with magnetic resonance (MR) imaging. MR findings were correlated with clinical, surgical, and arthroscopic findings. The injuries involved the medial retinacular ligament in 16 of 17 patients and the medial and lateral retinacular ligament in one patient. Nine of 17 patients showed MR evidence of a patellar dislocation. In these patients, a triad of findings that included focal impaction injuries involving the lateral femoral condyle, osteochondral injuries of the medial patellar facet, and injuries of the medial retinacular ligament were seen. Seven of the nine patients with patellar dislocation injuries had frank osteochondral injuries. The injured retinaculum had an indistinct, irregular appearance associated with edema and hemorrhage. The patellar dislocations were clinically unsuspected in the initial evaluation of eight of these nine patients. In eight of 17 patients, the mechanism of injury was a patellar tendon tear (n = 1) or valgus hyperextension (n = 7). In the seven patients with hyperextension injuries, three had associated meniscal and cruciate ligament tears. MR imaging can help define patellar retinacular and associated osteochondral injuries, which may be clinically useful information.     

Intrinsic risk factors for the development of achilles tendon overuse injury: a prospective study

BACKGROUND: Although Achilles tendon overuse injuries occur commonly, our understanding of the pathologic changes and the factors that predispose athletes to them is limited. PURPOSE: To identify measurable intrinsic risk factors for Achilles tendon overuse injuries. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: Sixty-nine male officer cadets followed the same 6-week basic military training. Before this training, each subject was evaluated for anthropometrical characteristics, isokinetic ankle muscle strength, ankle joint range of motion, Achilles tendon stiffness, explosive strength, and leisure and sports activity. During military training, Achilles tendon overuse injuries were registered and diagnosed by the same medical doctor. To identify the intrinsic risk factors, a multivariate analysis with the use of stepwise logistic regression was performed. The sensitivity, specificity, and cutoff values of the risk factors were evaluated by receiver operating characteristic curve analysis. RESULTS: Ten of the 69 male recruits (14.5%) sustained an Achilles tendon overuse injury diagnosed on the basis of medical history and clinical examination. Analysis revealed that male recruits with lower plantar flexor strength and increased dorsiflexion excursion were at a greater risk of Achilles tendon overuse injury. The cutoff value of the plantar flexor strength at 85% sensitivity was 50.0 N.m, with a 4.5% specificity; the cutoff value of the dorsiflexion range of motion at 85% sensitivity was 9.0 degrees , with 24.2% specificity. CONCLUSIONS: The strength of the plantar flexors and amount of dorsiflexion excursion were identified as significant predictors of an Achilles tendon overuse injury. A plantar flexor strength lower than 50.0 N.m and dorsiflexion range of motion higher than 9.0 degrees were possible thresholds for developing an Achilles tendon overuse injury.