Magnetic resonance imaging findings of injuries to the calf muscle complex

Trivial incident leading to tennis leg managed conservatively: A case report

Since 1883, "tennis leg" has described various acute calf injuries linked to activities such as tennis serving or stair climbing. Current research suggests that tennis leg is caused by the injury of the medial head of the gastrocnemius muscle. This case report details the case of a 35-year-old male who suffered sudden and intense calf pain after a minor leg extension injury. The diagnosis of tennis leg, likely involving gastrocnemius muscle (partial tear), was made using clinical evaluation and ultrasonography (USG). The patient was managed conservatively and regained normal muscle function at the 4-month follow-up. Diagnosis, aided by clinical examination and imaging like USG, is crucial for accurate differentiation from conditions like deep vein thrombosis, as was done in our case. Treatment typically involves conservative measures like rest, ice, compression, elevation, analgesics, and physiotherapy, while surgery may be considered in severe cases. Regular follow-up is vital for monitoring recovery progress and adjusting treatment plans as needed. This case emphasizes the importance of promptly recognizing tennis leg injuries and differentiating it from other disorders with similar presentations.

Guide to Muscular Injuries and Common Ligamentous Injuries Among Soccer Players

With over 250 million players worldwide, soccer is the most popular sport in the world. The overall number of players at professional, amateur, and recreational levels has increased along with an increase in player diversity, including age and sex. These increases in player numbers, as well as a variety of demographics, have resulted in an increase in soccer-related injuries. Injury in the professional setting can lead to time off the field and an effect on team results and earnings. Injury at the amateur and recreational levels can lead to time off work, away from other activities, and change in activities of daily living. We provide an extensive list of common injuries sustained by soccer players, their pathophysiology, diagnosis, treatment, and general guidelines on return to play.

3T 31P/1H calf muscle coil for 1H and 31P MRI/MRS integrated with NIRS data acquisition

PURPOSE

Our aim was to design and build a 3T 31P/1H calf coil that is capable of providing both good 31P and 1H transmit and receive performance, as well as being capable of accommodating a near-infrared spectroscopy (NIRS) device for simultaneous NIRS data and MRI/MRS acquisition.

METHOD

In this work, we propose a new 3T 31P/1H birdcage combination design consisting of two co-centrically positioned birdcages on the same surface to maximize transmit efficiency and sensitivity for both nuclei. The 31P birdcage is a high-pass birdcage, whereas the 1H birdcage is a low-pass one to minimize coupling. The diameter of the 31P/1H birdcage combination was designed to be large enough to accommodate a NIRS device for simultaneous NIRS data and MRI/MRS acquisition.

RESULTS

The one-layer coil structure of the birdcage combination significantly streamlines the mechanical design and coil assembly process. Full-wave simulation results show that the 31P and 1H are very well decoupled with each other, and the 1H and 31P SNR surpasses that of their standalone counterparts in the central area. Experiment results show that the inclusion of a NIRS device does not significantly affect the performance of the coil, thus enabling simultaneous NIRS and MRI readouts during exercise.

CONCLUSION

Our findings demonstrate the feasibility and effectiveness of this dual-tuned coil design for combined NIRS and MRS measurements, offering potential benefits for studying metabolic and functional changes in the skeletal muscle in vivo.

Do the fasciae of the soleus have a role in plantar fasciitis?

Plantar fasciitis is a chronic, self-limiting, and painful disabling condition affecting the inferomedial aspect of the heel, usually extending toward the metatarsophalangeal joints. There is compelling evidence for a strong correlation between Achilles tendon (AT) loading and plantar aponeurosis (PA) tension. In line with this, tightness of the AT is found in almost 80% of patients affected by plantar fasciitis. A positive correlation has also been reported between gastrocnemius-soleus tightness and heel pain severity in this condition. Despite its high prevalence, the exact etiology and pathological mechanisms underlying plantar heel pain remain unclear. Therefore, the aim of the present paper is to discuss the anatomical and biomechanical substrates of plantar fasciitis with special emphasis on the emerging, though largely neglected, fascial system. In particular, the relationship between the fascia, triceps surae muscle, AT, and PA will be analyzed. We then proceed to discuss how structural and biomechanical alterations of the muscle-tendon-fascia complex due to muscle overuse or injury can create the conditions for the onset of PA pathology. A deeper knowledge of the possible molecular mechanisms underpinning changes in the mechanical properties of the fascial system in response to altered loading and/or muscle contraction could help healthcare professionals and clinicians refine nonoperative treatment strategies and rehabilitation protocols for plantar fasciitis.

Posterior Leg Pain: Understanding Soleus Muscle Injuries

Soleus muscle injuries are frequently unrecognized, representing a common cause of sports inactivity. This is mainly because little is known about the anatomy of the soleus muscle and the clinical manifestations of injury. Unlike other muscles, the soleus muscle has a complex myoconnective structure with three intramuscular tendons, which makes the interpretation of muscle pathologic conditions challenging. Soleus muscle injuries can be acute or chronic and are usually considered to be a minor discomfort by both the patient and the sports medicine physician, leading to a relatively quick return to sporting activity with a high risk for reinjury. The authors review the soleus muscle anatomy and the importance of being familiar with the most frequent locations of injuries, which are fundamental aspects that every radiologist should understand to avoid underdiagnosis. The role of imaging, the clinical manifestations of injuries, and the differential diagnoses are key aspects to know when evaluating posterior leg pain. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2022.

Calf Strain in Athletes

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Calf strain is a common condition. In high-performance athletes, calf strain contributes to a substantial absence from competition.

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Player age and history of a calf strain or other leg injury are the strongest risk factors for calf strain injury and reinjury.

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Although the diagnosis is often clinical, magnetic resonance imaging and ultrasound are valuable to confirm the location of the strain and the grade of injury.

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Nonoperative treatment is effective for most calf strain injuries. Operative management, although rarely indicated, may be appropriate for severe cases with grade-III rupture or complications.

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Further investigation is necessary to elucidate the benefits of blood flow restriction therapy, deep water running, lower-body positive pressure therapy, platelet-rich plasma, and stem cell therapy for calf strain rehabilitation.

Muscular Echovariation as a New Biomarker for the Classification of Soleus Muscle Pathology: A Cross-Sectional Study

Background: Soleus injury is one of the most common soft tissue tears during sport activities. Current classifications of muscle tears are based on symptoms and tear size and they do not contribute suitable evidence-based treatment protocols. The objective of this study was to analyze the most frequent echotexture findings of patients with soleus muscle injury, located in the central intramuscular tendon (IMT), and healthy people to determine whether they behave differently and to propose an ultrasound (US)-based classification. Methods: eighty-four athletes, who played in sport activities comprising lower limbs. Echotexture characteristics of soleus muscle were reviewed for 84 subjects. They were divided based on the muscle echogenicity in three groups (Injury Type 1 group, Injury type 2 group and healthy group). Echointensity (EI) and Echovariation (EV) were taken in all groups like quantitative US variable. Results. The Injury Type 1 group was identified by a hypoechoic area and characterized by a higher EV; and Injury Type 2 group was identified by a fibrotic area and characterized by a lower EV. The echogenic pattern of healthy people obtained an intermediate value of EV between both injured soleus types. Conclusions. EV may be useful to classify different types of soleus muscle pathology according to the echogenicity pattern. An innovative proposed US-based classification system for soleus tears may be used to guide treatment decisions for patients with central tendon injury of soleus muscle.

Ultrasound Imaging Evaluation of Textural Features in Athletes with Soleus Pathology-A Novel Case-Control Study

Background: the aim of this study was to compare the echotexture of patients with soleus muscle injury and age matched controls. Methods: a sample of 62 athletes was recruited at the private clinic and was divided in two group: a healthy group (n = 31) and a soleus pathology group whose athletes had soleus muscle injury, located in the central tendon (n = 31). The muscle thickness (MTh), echointensity (EI) and echovariation (EV) were analyzed. An intra-rater reliability test (Intraclass Correlation Coefficient-ICC) was performed in order to analyze the reliability of the values of the measurements. Results: Sociodemographic variables did not show statistically significant differences (p > 0.05). Ultrasound imaging measurements who reported statistically significant differences were EI (p = 0.001) and standard deviation (SD) (p = 0.001). MTh and EV variables did not show statistically significant differences (p = 0.381 and p = 0.364, respectively). Moreover, reliability values for the MTh (ICC = 0.911), EI (ICC = 0.982), SD (ICC = 0.955) and EV (ICC = 0.963). Based on these results the intra-rater reliability was considered excellent. Conclusion: Athletes with a central tendon injury of soleus muscle showed a lower EI when they were compared to healthy athletes. The echogenicity showed by the quantitative ultrasound imaging measurement may be a more objective parameter for the diagnosis and follow-up the soleus muscle injuries.

"Tennis Leg": A State-of-the-Science Review

BACKGROUND

Tennis leg (TL), a musculotendon injury to the gastrocnemius, has been associated with the eponymous sport since 1883. This article examines the historical context of TL as a sports compared with an occupational injury. This was juxtaposed with the history of tennis elbow, a tendon injury to the upper extremity also associated with sport.

METHODS

Bibliometric databases (PubMed, Web of Science [WOS], Hathi Trust) were keyword-searched; relevant citations were investigated in depth.

RESULTS

The search yielded 71 citations for TL (PubMed). The majority (n = 43) were key word linked to sport terms; only one was linked to work-related search terms. Furthermore, none of the top four cited publications (Web of Science) alluded to work-related risk factors in TL in full textual analysis. Hathi Trust yielded the earliest work-related case, reported in a non-biomedical source. Tennis elbow was more frequently reported (n = 189 citations in PubMed) and more frequently linked (n = 193; 9.7%) to occupational search terms.

CONCLUSION/APPLICATION TO PRACTICE

The history of TL, juxtaposed with tennis elbow, demonstrates how nosology can influence but does not wholly explain disease attribution, potentially to the detriment of taking into account occupational causality. The lack of recognition of occupational factors revealed in this literature search was notable because TL occurred most commonly in males of working age. By providing perspective on how historical context and nosology can affect the conceptualization of disease, this review may help inform prevention, treatment, and regulatory policy.

Surgical Treatment of Medial Gastrocnemius Tear

Medial gastrocnemius tears typically occur with forced dorsiflexion while the knee is extended. Myotendinous injuries occur most commonly, which are almost always treated without surgery. If a tendinous injury or avulsion occurs, nonoperative treatment should first be attempted. However, in patients where forceful plantar flexion is required for their desired activities or occupation, surgical fixation is an important treatment option. Postoperative bracing should be used to protect the repair with a graduated therapy progression, including range of motion followed by strengthening and return to activities. This technical note describes the technique for a safe and reliable medial gastrocnemius tendinous repair using two suture anchors.

Soleus strain: an underestimated injury?

The medial gastrocnemius is the most commonly injured muscle in the calf, and while traumatic lesions of the medial gastrocnemius are frequently described in the medical literature and clinical and sonographic diagnoses are easy, those of the soleus are less easily recognisable clinically or by sonography. We present a case of traumatic lesions of the medial gastrocnemius, diagnosed clinically and with ultrasound, while MRI also detected two lesions of the soleus. The case presented and the review of the literature highlight how clinical and ultrasound examinations can lead to misunderstandings about traumatic injury to the soleus.

M-Mode Ultrasound Examination of Soleus Muscle in Healthy Subjects: Intra- and Inter-Rater Reliability Study

Objective: M-mode ultrasound imaging (US) reflects the motion of connective tissue within muscles. The objectives of this study were to evaluate inter-rater and intra-rater reliability of soleus muscle measurements between examiners with different levels of US experience in asymptomatic subjects and to investigate the level of soleus muscle isometric activity in two positions (knee extended and knee flexed at 30°). Methods: Thirty volunteers without a history of ankle pain were evaluated with US examinations of the soleus muscle. Each muscle was scanned independently by two evaluators. Muscle at rest thickness, maximal isometric contraction thickness, time and velocity measures were detailed and blinded to the other examiner. Results: Intra- and inter-rater reliability at rest, in maximal isometric contraction thickness, contraction time and contraction velocity measures for both positions (extended and flexed knee) were reported from good to excellent for all outcome measurements. The position with the knee extended reported a statistically significant increase in thickness after motion showing 1.33 ± 0.27 mm for measurements at rest thickness with knee extended versus 1.50 ± 0.29 mm for measurements at end thickness with the knee in flexed position (p = 0.001), as well as 1.31 ± 0.23 mm for rest thickness with the knee in flexed position measurements with respect to 1.34 ± 0.24 mm for maximal isometric contraction thickness with extended knee measurements (p = 0.058). Conclusions: This study found that intra- and inter-examiner reliability of M-mode ultrasound imaging of the soleus muscle was excellent in asymptomatic subjects and the soleus muscle activity was different between the position with the knee extended and the position with the knee flexed.

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.

Ultrasound-Guided Percutaneous Needle Electrolysis in Dancers with Chronic Soleus Injury: A Randomized Clinical Trial

Damage to intramuscular tendons is very common in sports injuries, specifically in soleus muscle injuries. This study sought to compare the effects of applying ultrasound- (US-) guided percutaneous needle electrolysis (PNE) in combination with an eccentric exercise program on pain and functionality in dancers with chronic soleus injury, located in the central tendon. Thirty dancers with injured central tendon of the soleus muscle were randomly allocated to a PNE group (n = 10), an eccentric exercise group (n = 10), or a combined group (n = 10). Pain, ankle dorsiflexion range of motion (DROM), endurance, the heel raise test, the DFOS questionnaire, and the minimal clinically important difference (MCID) were analyzed at baseline and after treatment (four weeks). Over half (52%) of the dancers had a chronic soleus muscle injury. Variables for pain, DROM, the heel rise test, ADL, technique, DFOS total, and DFOS-subjective variables showed significant differences (P < 0.05) in pretreatment and posttreatment in all groups, whereas no significant differences were observed between intervention groups. However, the combined group showed a higher percentage of changes compared to the other groups, and these dancers had greater perceived changes (MCID = 4.70 ± 1.42). The conclusion of the study was that dancers with chronic soleus injury, located in the central tendon, treated with a combination of US-guided PNE and an eccentric exercise program displayed improved outcomes compared to the application of PNE therapy or eccentric exercise alone. The US-guided PNE, combined with an eccentric exercise program, is a useful therapeutic tool for the treatment of chronic soleus injury, located in the central tendon. The trial is registered with NCT04042012.

Anatomical study of the soleus: Application to improved imaging diagnoses

INTRODUCTION

Strains of the soleus are widely found both in amateur and professional athletes. For their accurate regional diagnoses, understanding the anatomy of the spatial relationship between muscular fibers and tendinous structures is important because their interfaces are susceptible sites to muscle strains. Therefore, this study evaluated the precise architecture of the soleus.

MATERIALS AND METHODS

We evaluated the precise anatomical architecture of the soleus in 87 formaldehyde-fixed soleus muscles. To calculate mean relative physiological cross-sectional area of each muscular fiber compartment, we measured the fiber length, volume, and pennation angle in isolated compartments.

RESULTS

The posterior soleus surface was covered by a broad aponeurotic posterior insertion tendon (PIT), which continued inferiorly to the insertion tendon. The anterior surface had three aponeurotic origin tendons, lateral origin tendon (LOT), medial origin tendon (MOT), and tendinous arch, which were arranged along the soleus margins. The anterior bipennate muscle portion (ABP), surrounded by the three origin structures, terminated as the sagittal insertion tendon (SIT), which continued inferiorly to PIT. The posterior main muscle portion behind LOT and MOT was separated into lateral and medial portions by the SIT. The soleus thus possessed a broad musculotendinous junction. Furthermore, ABP exhibited wide structural diversity in shape and size: in extreme cases, it was duplicated or absent.

CONCLUSION

Systematic anatomical descriptions of the soleus will be useful for accurate regional diagnosis of its strains with magnetic resonance imaging and ultrasonography.

Calf muscle strain injuries in elite Australian Football players: A descriptive epidemiological evaluation

BACKGROUND

Calf muscle strain injuries (CMSI) show consistent rates of prevalence and re-injury in elite Australian Football players. An epidemiological evaluation is warranted to better understand the clinical presentation and recovery of CMSI.

PURPOSE

First, to describe the epidemiology of CMSI in elite Australian Football players. Second, to determine if recovery following injury is different according to: (a) injury type (index vs re-injury); (b) muscle injured (soleus vs gastrocnemius); and (c) mechanism of injury (running-related activity vs non running-related activity).

STUDY DESIGN

Descriptive epidemiological.

METHODS

Data retrieved from the Soft Tissue injury Registry of the Australian Football League were analyzed. Sixteen clubs submitted data on CMSI from 2014 to 2017. Data included: player characteristics, training and match history at the time of injury, MRI, and the time to reach recovery milestones.

RESULTS

One hundred and eighty-four CMSI were included (149 index injuries; 35 re-injuries). Soleus injuries were most prevalent (84.6%). Soleus injuries took 25.4 ± 16.2 days to return to play, whereas gastrocnemius injuries took 19.1 ± 14.1 days (P = .097). CMSI sustained during running-related activities took approximately 12 days longer to recover than injuries sustained during non running-related activities (P = .001). Compared to index injuries, re-injuries involved older players (P = .03) and significantly more time was taken to run at >90% of maximum speed, return to full training, and return to play (P ≤ .001). Almost all of the observed re-injuries involved soleus (91.4%).

CONCLUSION

Soleus injuries are more prevalent than gastrocnemius injuries in elite Australian Football players. Prognosis appears to be influenced by clinical factors, with CMSI sustained during running-related activities and re-injuries needing more time to recover.

Is It All About the Fascia? A Systematic Review and Meta-analysis of the Prevalence of Extramuscular Connective Tissue Lesions in Muscle Strain Injury

Background:

The fascia has been demonstrated to represent a potential force transmitter intimately connected to the underlying skeletal muscle. Sports-related soft tissue strains may therefore result in damage to both structures.

Purpose:

To elucidate the prevalence of connective tissue lesions in muscle strain injury and their potential impact on return-to-play (RTP) duration.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

Imaging studies describing frequency, location, and extent of soft tissue lesions in lower limb muscle strain injuries were identified by 2 independent investigators. Weighted proportions (random effects) were pooled for the occurrence of (1) myofascial or fascial lesions, (2) myotendinous lesions, and (3) purely muscular lesions. Study quality was evaluated by means of an adapted Downs and Black checklist, which evaluates reporting, risk of bias, and external validity.

Results:

A total of 16 studies (fair to good methodological quality) were identified. Prevalence of strain injury on imaging studies was 32.1% (95% CI, 24.2%-40.4%) for myofascial lesions, 68.4% (95% CI, 59.6%-76.6%) for myotendinous lesions, and 12.7% (95% CI, 3.0%-27.7%) for isolated muscular lesions. Evidence regarding associations between fascial damage and RTP duration was mixed.

Conclusion:

Lesions of the collagenous connective tissue, namely the fascia and the tendinous junction, are highly prevalent in athletic muscle strain injuries. However, at present, their impact on RTP duration is unclear and requires further investigation.

Healing Process of Gastrocnemius Muscle Injury on Ultrasonography Using B-Mode Imaging, Power Doppler Imaging, and Shear Wave Elastography

OBJECTIVES

Muscle injury often occurs in sports activity. To avoid reinjury, it is important to determine the appropriate period until return to play after injury. The purpose of this study was to evaluate characteristics of the healing process for gastrocnemius muscle injury by B-mode imaging, power Doppler (PD) imaging, and shear wave elastography (SWE).

METHODS

Twenty patients with acute calf musculotendinous injury were enrolled. Scar thickness on B-mode imaging, new vessels according to PD grades, and SWE values in the muscle, musculotendinous junction, and tendon of the medial head of gastrocnemius were measured at 4, 8, and 12 weeks after injury.

RESULTS

Scar thickness was significantly larger at 8 and 12 weeks compared with 4 weeks (P < .01 for both). Power Doppler grades at 4 and 8 weeks were significantly higher compared with 12 weeks (P < .01 for both). Shear wave elastographic values in the muscle on the injury side were significantly higher at 8 and 12 weeks compared with 4 weeks (P < .01 for both), whereas those in the musculotendinous junction on the injury side were significantly higher at 12 weeks compared with 4 and 8 weeks (P < .01; P = .01, respectively).

CONCLUSIONS

B-mode imaging, PD imaging, and SWE can measure the healing process after musculotendinous injury of the gastrocnemius medial head.

The effect of deloading tape on medial gastrocnemius muscle fascicle behaviour during dynamic exercise

This study examined the effect of diamond deloading tape on medial gastrocnemius (MG) muscle behaviour during exercise in healthy adults (n = 27). A randomised cross-over trial assessed the effect of tape (no-tape, sham-tape and deload-tape) on ankle and MG fascicle kinematics during three heel raise-lower exercises [double leg (DL), single leg (SL) and loaded single leg (LSL)]. There was no effect of tape on standing fascicle length (FL) or pennation angle (PA), or ankle or knee joint angle. There was a significant effect of tape on ankle kinematics for all exercises. Both the deload-tape and sham-tape resulted in less ankle plantar flexion but had no effect on dorsiflexion. There was a significant effect of tape on FL change for the SL and LSL exercise. Compared to no-tape, the deload-tape resulted in less fascicle shortening during ankle plantar flexion, and more fascicle lengthening during ankle dorsiflexion. For the LSL exercise, deload-tape caused MG fascicles to operate at longer lengths, for a given joint angle. Diamond taping, with or without added tension, has only a small effect on ankle and MG fascicle kinematics during the heel raise-lower exercise. With the exception of the LSL exercise, both tape conditions resulted in similar changes in the FL-angle relations.

Muscle Injuries in Sports: A New Evidence-Informed and Expert Consensus-Based Classification with Clinical Application

Muscle injuries are among the most common injuries in sport and continue to be a major concern because of training and competition time loss, challenging decision making regarding treatment and return to sport, and a relatively high recurrence rate. An adequate classification of muscle injury is essential for a full understanding of the injury and to optimize its management and return-to-play process. The ongoing failure to establish a classification system with broad acceptance has resulted from factors such as limited clinical applicability, and the inclusion of subjective findings and ambiguous terminology. The purpose of this article was to describe a classification system for muscle injuries with easy clinical application, adequate grouping of injuries with similar functional impairment, and potential prognostic value. This evidence-informed and expert consensus-based classification system for muscle injuries is based on a four-letter initialism system: MLG-R, respectively referring to the mechanism of injury (M), location of injury (L), grading of severity (G), and number of muscle re-injuries (R). The goal of the classification is to enhance communication between healthcare and sports-related professionals and facilitate rehabilitation and return-to-play decision making.

MRI detection of soleus muscle injuries in professional football players

OBJECTIVES

To describe magnetic resonance imaging (MRI) characteristics of soleus muscle injuries in symptomatic professional football players stratified according to both the Munich consensus statement and the British Athletics Muscle Injury Classification (BAMIC), and to investigate the association between specific MRI features and the "return to play" (RTP).

MATERIALS AND METHODS

Professional football players with an episode of acute posterior calf pain and impaired function, subsequent to sports activity, underwent ultrasound followed by MRI examination reviewed by two different radiologists with more than 10 years of experience in the musculoskeletal system. MRI features and RTP outcome were evaluated for all types of injuries.

RESULTS

During a 36-month period, a total of 20 professional football players were evaluated. According to the Munich consensus, 11 were type 3A, 8 were type 3B, and 1 was type 4, whereas according to the BAMIC, 11 lesions were considered grade 1, 4 grade 2, 4 grade 3, and 1 grade 4. RTP data were available for all patients (mean 3.3 ± 1.6 weeks). Both the Munich consensus and the BAMIC correlated with RTP (Spearman correlation = 0.982 and p < 0.0001 and 0.886 and p < 0.0001 respectively). Extension of edema was an independent prognostic factor for RTP in two different models of multivariate regression analysis (p = 0.044 model A; p = 0.031 model B).

CONCLUSIONS

The Munich consensus and BAMIC grading systems are useful tools for defining the patient's prognosis and proper rehabilitation time after injury. The MRI feature that we should carefully look for is the extension of edema, as it seems to significantly affect the RTP.

Connective tissue injury in calf muscle tears and return to play: MRI correlation

Objective

The aim of our study was to assess a group of patients with calf muscle tears and evaluate the integrity of the connective tissue boundaries and interfaces. Further, we propose a novel MRI grading system based on integrity of the connective tissue and assess any correlation between the grading score and time to return to play. We have also reviewed the anatomy of the calf muscles.

Materials and methods

We retrospectively evaluated 100 consecutive patients with clinical suspicion and MRI confirmation of calf muscle injury. We evaluated each calf muscle tear with MRI for the particular muscle injured, location of injury within the muscle and integrity of the connective tissue structure at the interface. The muscle tears were graded 0–3 depending on the degree of muscle and connective tissue injury. The time to return to play for each patient and each injury was found from the injury records and respective sports doctors.

Results

In 100 patients, 114 injuries were detected. Connective tissue involvement was observed in 63 out of 100 patients and failure (grade 3 injury) in 18. Mean time to return to play with grade 0 injuries was 8 days, grade 1 tears was 17 days, grade 2 tears was 25 days and grade 3 tears was 48 days (p<0.001).

Conclusion

The integrity of the connective tissue can be used to estimate and guide the time to return to play in calf muscle tears.

Muscle Shear Moduli Changes and Frequency of Alternate Muscle Activity of Plantar Flexor Synergists Induced by Prolonged Low-Level Contraction

During prolonged low-level contractions, synergist muscles are activated in an alternating pattern of activity and silence called as alternate muscle activity. Resting muscle stiffness is considered to increase due to muscle fatigue. Thus, we investigated whether the difference in the extent of fatigue of each plantar flexor synergist corresponded to the difference in the frequency of alternate muscle activity between the synergists using muscle shear modulus as an index of muscle stiffness. Nineteen young men voluntarily participated in this study. The shear moduli of the resting medial and lateral gastrocnemius muscles (MG and LG) and soleus muscle (SOL) were measured using shear wave ultrasound elastography before and after a 1-h sustained contraction at 10% peak torque during maximal voluntary contraction of isometric plantar flexion. One subject did not accomplish the task and the alternate muscle activity for MG was not found in 2 subjects; therefore, data for 16 subjects were used for further analyses. The magnitude of muscle activation during the fatiguing task was similar in MG and SOL. The percent change in shear modulus before and after the fatiguing task (MG: 16.7 ± 12.0%, SOL: −4.1 ± 13.9%; mean ± standard deviation) and the alternate muscle activity during the fatiguing task (MG: 33 [20–51] times, SOL: 30 [17–36] times; median [25th–75th percentile]) were significantly higher in MG than in SOL. The contraction-induced change in shear modulus (7.4 ± 20.3%) and the alternate muscle activity (37 [20–45] times) of LG with the lowest magnitude of muscle activation during the fatiguing task among the plantar flexors were not significantly different from those of the other muscles. These results suggest that the degree of increase in muscle shear modulus induced by prolonged contraction corresponds to the frequency of alternate muscle activity between MG and SOL during prolonged contraction. Thus, it is likely that, compared with SOL, the alternate muscle activity of MG occurs more frequently during prolonged contraction due to the greater increase in fatigue of MG induced by the progression of a fatiguing task.

MRI assessment of calf injuries in Australian Football League players: findings that influence return to play

OBJECTIVE

Calf muscle strains have become increasingly prevalent in recent seasons of the Australian Football League (AFL) and represent a significant cause of time lost from competition. The purpose of this study was to examine the association between MRI features of calf muscle strains and games missed and to thereby identify parameters that are of prognostic value.

MATERIALS AND METHODS

A retrospective analysis of MRI scans of AFL players with calf strains referred to a musculoskeletal radiology clinic over a 5-year period (2008-2012) was performed. The muscle(s) and muscle component affected, the site and size of strain, and the presence of an intramuscular tendon tear or intermuscular fluid were recorded. These data were cross-referenced with whether a player missed at least one game. Imaging features of prognostic value were thus identified.

RESULTS

Sixty-three athletes had MRI scans for calf muscle strains. Soleus strains were more common than strains of other muscles. Players with soleus strains were more likely to miss at least one game if they had multiple muscle involvement (p = 0.017), musculotendinous junction strains (p = 0.046), and deep strains (p = 0.036). In a combined analysis of gastrocnemius and soleus strains, intramuscular tendon tears were observed in a significantly greater proportion of players who missed games (p = 0.010).

CONCLUSION

Amongst AFL players with calf injuries, there is an association between missing at least one game and multiple muscle involvement, musculotendinous junction strains, deep strain location, and intramuscular tendon tears. In this setting, MRI may therefore provide prognostic information to help guide return-to-play decisions.

Muscular Calf Injuries in Runners

Calf pain is a common complaint among runners of all ages but is most frequent in masters athletes. This article focuses on injuries to the triceps surae or true 'calf muscles.' The most common calf injury is a tear of the medial gastrocnemius muscle (Tennis Leg) but other structures including the lateral gastrocnemius, plantaris and soleus also may be the cause of muscular pain. This article looks at the presentation, evaluation, and treatment of these injuries. We also highlight some examples of musculoskeletal ultrasound which is a valuable tool for rapid diagnosis of the cause and extent of injury.

Clinical, radiographic, and magnetic resonance imaging findings of gastrocnemius musculotendinopathy in various dog breeds

OBJECTIVES

To describe clinical, radiographic, and magnetic resonance imaging (MRI) findings in 16 dogs diagnosed with gastrocnemius musculotendinopathy.

METHODS

Retrospective evaluation of medical records, radiographs, and MRI results, as well as follow-up completed by telephone questionnaire.

RESULTS

Most dogs had chronic hindlimb lameness with no history of trauma or athletic activities. Clinical examination revealed signs of pain on palpation without stifle joint instability. Seven dogs had radiographic signs of osteophyte formation on the lateral fabella. Magnetic resonance imaging revealed T2 hyperintensity and uptake of contrast agent in the region of the origin of the gastrocnemius muscle. Changes were found in the lateral and medial heads of the gastrocnemius. Conservative treatment resulted in return to full function in 11 dogs. Two dogs showed partial restoration of normal function, one dog showed no improvement. Two dogs were lost to follow-up.

CLINICAL SIGNIFICANCE

Gastrocnemius musculotendinopathy is a potential cause of chronic hindlimb lameness in medium to large breed dogs. A history of athletic activity must not necessarily be present. Magnetic resonance imaging shows signal changes and uptake of contrast agent in the region of the origin of the gastrocnemius muscle. A combination of T1 pre- and post-contrast administration and T2 weighted sequences completed by a fat-suppressed sequence in the sagittal plane are well-suited for diagnosis. Conservative treatment generally results in return to normal function.

Imaging of rectus femoris proximal tendinopathies

The rectus femoris is the most commonly injured muscle of the anterior thigh among athletes, especially soccer players. Although the injury pattern of the muscle belly is well documented, less is known about the anatomy and specific lesions of the proximal tendons. For each head, three distinctive patterns may be encountered according to the location of the injury, which can be at the enthesis, within the tendon, or at the musculotendinous junction. In children, injuries correspond most commonly to avulsion of the anteroinferior iliac spine from the direct head and can lead to subspine impingement. Calcific tendinitis and traumatic tears may be encountered in adults. Recent studies have shown that traumatic injuries of the indirect head may be underdiagnosed and that injuries of both heads may have a surgical issue. Finally, in the case of tears, functional outcome and treatment may vary if the rupture involves one or both tendons and if the tear is partial or complete. Thus, it is mandatory for the radiologist to know the different ultrasound and magnetic resonance imaging (MRI) patterns of these lesions in order to provide accurate diagnosis and treatment. The purpose of this article is to recall the anatomy of the two heads of rectus femoris, describe a reliable method of assessment with ultrasound and MRI and know the main injury patterns, through our own experience and literature review.

Gastrocnemius tendinosis--A frequent finding on MRI knee examination

OBJECTIVE

Gastrocnemius tendinosis (GT) is one potential cause for posterior knee pain, commonly overlooked on clinical examinations and imaging. This study assesses the frequency of GT on MR imaging in a convenience sample based on a database search and associations with other articular pathologies and clinical findings.

SUBJECTS AND METHODS

With IRB approval, retrospective review was completed on 300 randomly selected MR knee exams performed from February 2009 to June 2010. Following de-identification, axial T2 and sagittal PD images, with or without fat suppression, were reviewed by 2 radiologists. The gastrocnemius tendon femoral attachments were graded as normal, mild (few cysts, thickening, intermediate signal) or severe GT (multiple cysts, marrow edema, tear). Select associated MR findings of internal derangement were documented. Clinical charts were reviewed for clinical presentation, physical exam findings, and select demographics.

RESULTS

The inter-observer reliability for presence/grading of GT was very high (kappa statistic=0.97). Frequency of GT was 50.33%, most frequently involving medial head of gastrocnemius (63.6%). Grades of GT were 41.7% and 17.2% for mild and severe respectively. Univariate analysis showed statistically significant relationship between grade of GT with arthrosis (p=0.05) and clinical joint effusion (p=0.02). Multivariate analysis showed higher odds of severe GT for individuals with medial plus lateral GT. Statistical significance was noted for presence of both GT and ACL tear (13.9%; p=0.02).

CONCLUSION

Significant findings of our analysis included GT presented with predominant involvement of medial head of gastrocnemius tendon, mild in severity, strong association with ACL tear, presented frequently as posterior knee pain, limited joint motion and clinical joint effusion. However, there was no statistically significant association between demographic features and medical comorbidities in the patients. Increased understanding of frequency of GT allows more accurate reporting of MR knee exam and systematic search for associated abnormalities.

Pattern of Fascicular Involvement in Midportion Achilles Tendinopathy at Ultrasound

BACKGROUND

The Achilles tendon is composed of fascicles from the soleus and gastrocnemius muscles, which are identifiable as discrete components at anatomical dissection.

HYPOTHESIS

The pattern of fascicular involvement in Achilles tendinopathy may be characterized at ultrasound, and this characterization is reliable between different observers.

STUDY DESIGN

Cross-sectional diagnostic study.

LEVEL OF EVIDENCE

Level 3.

METHODS

One hundred cases of Achilles tendinopathy were retrospectively evaluated by 2 blinded musculoskeletal radiologists. Using a short-axis anatomical map, each case was categorized as involving the fascicular territories of the medial head of gastrocnemius, lateral head of gastrocnemius, soleus, or combinations of these, or as indeterminate.

RESULTS

Both radiologists agreed on the fascicular involvement pattern in 93 of 100 cases; 20 involved only medial gastrocnemius territories, 8 lateral gastrocnemius, 15 soleus, 3 medial and lateral gastrocnemius, 21 medial gastrocnemius and soleus, 9 soleus and lateral gastrocnemius, and 16 the entire tendon, and 1 case was classified as indeterminate. In 7 cases, the interpretations were discordant. The kappa value was calculated as 0.92 (95% CI, 0.86-0.98) in keeping with a high level of interobserver agreement.

CONCLUSION

As assessed at ultrasound, most cases of Achilles tendinopathy involve the medial head of gastrocnemius and/or soleus fascicles.

CLINICAL RELEVANCE

The provided observational data will increase understanding of patterns of Achilles tendinopathy.

Soleus muscle injury: sensitivity of ultrasound patterns

OBJECTIVE

To assess the sensitivity of ultrasound in detecting soleus muscle lesions diagnosed on magnetic resonance imaging (MRI) and to characterize their location, ultrasound pattern, and evolution.

MATERIALS AND METHODS

Ultrasound and MRI studies were performed between May 2009 and February 2013 on all patients who presented to the Medical Services Clinic of the Catalan Sport Council with the initial onset of sharp pain in the calf compatible with injury of the soleus muscle. An inter-observer ultrasound reliability study was also performed.

RESULTS

A total of 55 cases of soleus injury were studied prospectively (22 with right leg involvement, 33 left) by ultrasound and MRI, which was utilized as the "gold standard." In MRI studies, 24 cases (43.7%) had myofascial injuries that were localized in the posterior aponeurosis (PMF) in 15 cases (27.3%) and in the anterior aponeurosis (AMF) in 9 (16.4%). Thirty-one cases (56.3%) were musculotendinous injuries, with 9 cases (16.4%) in the medial aponeurosis (MMT), 11 cases (20%) in the lateral aponeurosis (LMT), and 11 cases (20%) in the central tendon (CMT). In comparison to MRI, ultrasound was able to detect injury to the soleus in 27.2% of cases. No injuries were detected by ultrasound alone. Posterior myofascial injuries were more likely to be detected by ultrasound than anterior myofascial injuries or all types of musculotendinous injuries. Ultrasound patterns for each type of injury were described.

CONCLUSION

Ultrasound is not a sensitive technique for detecting and assessing soleus traumatic tears compared with MRI, although the sensitivity is enhanced by a thorough anatomically based ultrasound examination. Timing of the ultrasound examination may be of importance. Each type of soleus injury appears to have a characteristic ultrasound pattern based on a defect of connective expansions, the existence of small myofascial filiform collections, and the rarefaction of the fibrillar area.

Acute decrease in the stiffness of resting muscle belly due to static stretching

The purpose of the study was to examine the acute effect of static stretching exercise on the resting stiffness of gastrocnemius muscle belly. Ten healthy young adults performed standing wall stretching in dorsiflexion for 1 min at a time and repeated five times. Before and after stretching, the shear modulus was measured in medial and lateral heads of the resting gastrocnemius muscle with ultrasound shear-wave elastography. After the stretching, dorsiflexion range of motion (ROM) of the ankle joint increased (P < 0.01) by 3.9° and returned in 20 min. Immediately after stretching, shear modulus decreased (P < 0.01) by 14%, compared with before stretching across muscle heads. The decrease in shear modulus returned in 20 min after stretching. In the comparison group of 10 additional subjects, the standing intervention without stretching had no influence on these measures. There was a negative correlation between dorsiflexion ROM and shear modulus in either head before and after stretching. The results demonstrate the transient decreases in the stiffness of the resting gastrocnemius muscle belly and indicate that joint flexibility is greater in individuals with lower resting stiffness of the muscle belly.

Can local corticosteroid injection in the retrocalcaneal bursa lead to rupture of the Achilles tendon and the medial head of the gastrocnemius muscle?

PURPOSE

The purpose of the study is to explain the cause-effect relationship in three patients who reported combined ruptures of the Achilles tendon and the gastrosoleus complex 6 months after they had received corticosteroids injections for the management of retrocalcaneal bursitis.

METHODS

Three cryopreserved cadavers (three men, three left legs) were examined to assess the anatomic connection between the retrocalcaneal bursa and the Achilles tendon (distal and anterior fibers). Blue triptan medium contrast was injected.

RESULTS

An unexpected connection between the retrocalcaneal bursa and the anterior fibers of the Achilles tendon was found in all instances.

CONCLUSIONS

Local corticosteroid injection of the retrocalcaneal bursa may help the symptoms of retrocalcanear bursitis, but pose a risk of Achilles tendon rupture. This risk-benefit has to be taken into account when corticosteroid injections are prescribed to professional and high-level athletes.

Surgical treatment of gastrocnemius muscle ruptures

Rupture of the medial head of the gastrocnemius, known as "tennis leg", typically occurs when the muscle has been overstretched by dorsiflexion of the ankle with full knee extension. The classic clinical presentation is a middle-aged person who complains of sports-related acute pain in the mid portion of the calf, associated with a snapping sensation. Magnetic resonance imaging (MRI) or ultrasound is often required to evaluate patients with this condition. This injury is usually managed non-operatively, surgical treatment rarely being indicated according to published reports. One case of longstanding and one of recent rupture of the musculotendinous junction of the medial head of the gastrocnemius that were successfully treated by surgical repair are presented here and the MRI characteristics and indications for surgery are discussed.

The soleus muscle: MRI, anatomic and histologic findings in cadavers with clinical correlation of strain injury distribution

OBJECTIVE

The purpose of this study was to describe the normal anatomy of the soleus muscle using magnetic resonance (MR) imaging, anatomic dissection and histologic correlation in cadavers. The second objective of this study was to analyse the morphometry of the soleus muscle in normal volunteers. The final objective was to undertake a retrospective review of soleal strain injuries confirmed with MR imaging, with correlation made between the cadaveric anatomic findings and the MR imaging features.

MATERIALS AND METHODS

Eleven fresh cadaveric legs were studied using a high resolution 3.0 T (T) MR imaging scanner to obtain images in the axial, coronal and sagittal planes. After imaging, six specimens were dissected and evaluated by histological analysis, with the remaining five specimens then frozen and cut into axial sections. The corresponding levels on the MR examination were then compared with the levels of anatomic sectioning. MR imaging was also used to examine the soleus muscle in both legs of 20 healthy volunteers. Finally, 55 clinical cases of soleus muscle strains diagnosed between October 2006 and January 2011 that had also previously undergone MR imaging were re-evaluated. The location of strain injury was reviewed and correlated with the anatomic information that had been revealed in the anatomic component of our study.

RESULTS

Dissection of the soleus muscle revealed two proximal intramuscular aponeuroses (medial and lateral) that are formed as a direct continuation of the surrounding epimysium. From an anatomic, functional and pathologic perspective, these aponeuroses are considered in this study as intramuscular tendons, however they have been not previously described as such. These tendons penetrate deep into the muscle belly, from which the proximal muscle fibres of the soleus arise. Inferiorly, these muscle fibres insert onto a long distal central tendon that becomes confluent with the overlying distal tendon of gastrocnemius to form the Achilles tendon. Significant differences between the length of the central tendon on the right side (31.35 cm) and the left side (30.36 cm) were observed (p = .002), as well as the length of insertion of this tendon onto the Achilles tendon on the right side (7.19 cm) compared with the left (7.94 cm) (p = .02). The retrospective analysis identified five sites within the soleus where strains were distributed: musculotendinous junction sites (proximal medial strains accounting for 25.5% of all injuries, proximal lateral strains accounting for 12.7% and distal central tendon strains accounting for 18.2%) and myofascial sites (anterior strains accounting for 21.8% of all injuries and posterior strains accounting for 21.8%). Strains of the proximal medial musculotendinous junction were the most common of soleal muscle injuries, comprising 56.4% of all cases.

CONCLUSION

Current information on the detailed anatomy of the soleus muscle in the anatomic and radiological literature is lacking. Knowledge of this anatomy accounts for the distribution of sports-induced injuries within the soleus muscle-tendon unit and therefore assists in the accurate identification of these injuries, with possible prognostic benefit.

The aging athlete: part 1, "boomeritis" of the lower extremity

OBJECTIVE

The purpose of this review is to describe the physiologic changes that occur in the musculoskeletal system during aging and the common injuries that occur in the lower extremity as a consequence of these changes. Several clinical presentations are addressed, and their differential diagnoses are discussed with an emphasis on the most likely injury for each presentation.

CONCLUSION

A unique quality of the newly aging group of people referred to as baby boomers is their expectation to continue exercising as they grow older, thus the incidence of exercise-induced injuries among older people is increasing. The concepts behind factors that predispose older athletes to certain pathologic conditions that affect the muscles, tendons, and bones of the lower extremity must be understood.

Traumatic injuries of thigh and calf muscles in athletes: role and clinical relevance of MR imaging and ultrasound

Objectives

Magnetic resonance (MR) imaging and ultrasound have become valuable tools for evaluation of traumatic muscle injuries in athletes. Common athletic injuries include strain, contusion and avulsion, which are characterised by muscle fibre disruption, intramuscular haemorrhagic dissection, haematoma at the musculotendinous junction, and perifascial blood or haematoma.

Methods

MR imaging may allow clinicians to predict the time required before athletes can return to competition and the risk of injury recurrence.

Results

Fluid-sensitive MR sequences, e.g., fat-suppressed T2-weighted or proton density-weighted turbo spin echo (TSE), and short-tau inversion recovery (STIR) sequences are suitable for detecting oedematous changes in the musculotendinous unit, and for delineating intramuscular or perifascial fluid collections or haematoma. T1-weighted spin echo sequences are used to visualise atrophy and fatty infiltration and to differentiate between haemorrhage/haematoma and oedema. While ultrasound may play a role as an adjunctive imaging method, it is less accurate than MR images for assessing the extent of the injury and it cannot differentiate between new and old injuries.

Conclusions

In this pictorial review, imaging features of lower extremity muscle injuries including strain, contusion and avulsion are reviewed, focusing on MR and ultrasound imaging findings after initial injury and during follow-up, and their relevance in clinical practice is discussed.

Teaching points

• MR imaging may allow clinicians to predict time required before athletes can return to competition

• Fluid-sensitive MR sequences are suitable for detecting oedematous changes in the muscles

• T1-weighted sequences are used to differentiate between haemorrhage/haematoma and oedema.

• Ultrasound can also be used but is less accurate than MR imaging for assessing the extent of the injury

Pictorial essay: Ultrasonography in 'tennis leg'

Tennis leg is caused by a rupture of the medial head of the gastrocnemius muscle, usually at its distal musculotendinous junction region. However, tears in this muscle and its tendon are also included under the term ‘tennis leg’. It is seen regularly in practice and is an important cause of a painful calf. The common USG findings include: disruption of the pinnate pattern of the distal medial gastrocnemius, usually near the junction of the triceps surae (which is the echogenic line between the gastrocnemius, the soleus, and the plantaris muscles), fluid tracking along the fascia, adjacent hematoma, and intramuscular tears as well as hematomas. USG is useful for confirming the diagnosis, excluding other causes of a painful calf, for assessing the severity of the disease, and in follow-up.

Isolated partial tear and partial avulsion of the medial head of gastrocnemius tendon presenting as posterior medial knee pain

We present a case of medial head of gastrocnemius tendon tear. The type of injury widely reported in the literature is tear of the medial head of gastrocnemius muscle or 'tennis leg'. We previously reported an isolated partial tear and longitudinal split of the tendon to the medial head of gastrocnemius at its musculotendinous junction. The case we now present has notable differences; the tear was interstitial and at the proximal (femoral attachment) part of the tendon, the patient's symptoms and clinical examination suggested a medial meniscus tear, and magnetic resonance imaging demonstrated bone oedema at the tendon insertion site indicating a traction injury. Both cases suggest that isolated tear of the medial head of the gastrocnemius tendon may have a variety of presentations and appearances and should be considered in the differential diagnosis of tennis leg as well as medial meniscus tear.

Isolated tear of the tendon to the medial head of gastrocnemius presenting as a painless lump in the calf

We report on a case of isolated tear of the medial head of gastrocnemius tendon. The patient presented with a painless lump in the right calf and denied any prior history of trauma or strain to the leg. A longitudinal split of the tendon was demonstrated at ultrasound and magnetic resonance imaging (MRI). There were no other abnormalities and the gastrocnemius muscle was normal. There are no reports in the literature of isolated gastrocnemius tendon tear. To date the calf muscle complex injury described in this area is tearing of the medial head of gastrocnemius muscle, sometimes referred to as "tennis leg". We conclude that an isolated tear of the tendon to the medial head of gastrocnemius should be considered in the differential diagnosis of a lump or swelling in the upper medial area of the calf and we recommend ultrasound or MRI as the investigations of choice.