Deep Fascia Research Articles

Imaging and Image Processing Techniques for High-Resolution Visualization of Connective Tissue with MRI: Application to Fascia, Aponeurosis, and Tendon

Recent interest in musculoskeletal connective tissues like tendons, aponeurosis, and deep fascia has led to a greater focus on in vivo medical imaging, particularly MRI. Given the rapid T2* decay of collagenous tissues, advanced ultra-short echo time (UTE) MRI sequences have proven useful in generating high-signal images of these tissues. To further these advances, we discuss the integration of UTE with Diffusion Tensor Imaging (DTI) and explore image processing techniques to enhance the localization, labeling, and modeling of connective tissues. These techniques are especially valuable for extracting features from thin tissues that may be difficult to distinguish. We present data from lower leg scans of 30 healthy subjects using a non-Cartesian MRI sequence to acquire axial 2D images to segment skeletal muscle and connective tissue. DTI helped differentiate aponeurosis from deep fascia by analyzing muscle fiber orientations. The dual echo imaging methods yielded high-resolution images of deep fascia, where in-plane spatial resolutions were between 0.3 × 0.3 mm to 0.5 × 0.5 mm with a slice thickness of 3–5 mm. Techniques such as K-Means clustering, FFT edge detection, and region-specific scaling were most effective in enhancing images of deep fascia, aponeurosis, and tendon to enable high-fidelity modeling of these tissues.

Role of TSH in Predicting Malignant Thyroid Tumours

The study compares the two methods to determine which more accurately locates perforators, as confirmed by intraoperative findings. We included a prospective study with 50 consecutive patients who underwent varicose vein surgery in 2023 and 2024 for preoperative marking. The “T” approach uses Doppler marking to identify an inadequate perforator. The long limb of the T represents the superficial vein’s path, and the junction of the T indicates the perforator’s entry point into the deep fascia. Surgical correlation was done. The “T” method of Doppler marking proved to be simple to use and beneficial for intraoperative identification. In addition, it facilitated a more precise surgical approach, potentially leading to improved patient outcomes and reduced recurrence rates. Overall, the findings suggest that the “T” method may be a valuable tool in the preoperative assessment of varicose vein patients.

Copeman Nodules: A Rare Patient Case Occurring After a Herpes Zoster Infection

Copeman nodes are a herniation of subcutaneous adipose tissue into the underlying muscle layer, through a breach in the superficial muscle fascia. First described by Ries et al., these nodes were studied more closely by rheumatologists Copeman and Ackerman. These nodules may occur singularly or in groups and may be unilateral or bilateral. They are elastic to palpation, mobile, and vary in size from 1 to 3 cm. They are predominantly located in the lateral lumbar spine regions. The pain these nodes cause is superficial and constant but may be exacerbated by palpation and trunk movement. Sonography is essential for diagnosis as, due to their small size, they are difficult to detect with computed tomography or magnetic resonance imaging. Copeman nodes should be suspected in cases of chronic superficial lateral lumbar pain, especially when other causes have been excluded. This report describes a patient case with unusual onset of Copeman nodes, after contracting herpes zoster.

Cartilage graft and temporal muscle fascia graft in revision myringoplasty: a comparison of anatomical and functional results with an innovative surgical technique

BackgroundThe temporal muscle fascia is the most widely used type of tissue graft in revision myringoplasty procedures. The aim of this study was to verify if the use of a cartilage graft may be a valid alternative to temporalis fascia. Tympanic reperforations are frequent after myringoplasty, especially in complicated, large, or anterior perforations, so we decided to compare the neodrum stability of two different surgical techniques.Materials and methodsThe study was conducted on 42 patients who underwent revision myringoplasty, carried out with the overlay technique, between 2004 and 2020. In all patients, the retroauricular approach was used. The subjects included in the study were divided into 2 groups: the former was treated with a cartilage graft, while in the latter a temporalis fascia graft was used. In the comparison of the two groups, the following outcomes were taken into consideration: engraftment rate, incidence of complications, pre- and postoperative air conduction pure tone average and air-bone gap.ResultsThe success rate was 100% for the first group and 83.3% for the second, with a statistically not significant difference. Among the subjects treated with cartilage graft, complications were observed in 8.3% of the cases, while in patients treated with fascia graft the observed complication rate was 43.3% (p = 0.03), maybe due to the shorter follow-up period of the first group. The improvement of the air conduction pure tone average was greater with cartilage graft (p = 0.02), whereas the difference between air-bone gap closures in the two groups was not statistically significant.ConclusionThe cartilage graft can represent a valid alternative to temporal muscle fascia, guaranteeing excellent engraftment, fewer complication rate and satisfactory hearing outcomes.

Changes to muscle and fascia tissue after eighteen days of ankle immobilization post-ankle sprain injury: an MRI case study

BackgroundAnkle sprains often result in muscle atrophy and reduced range of motion, which can cause long-term ankle instabilities. Understanding the changes to muscle—such as atrophy—and concomitant changes to deep fascia—which may thicken alongside muscle loss—after ankle sprain injury is important to understanding structural changes about the joint and how they might contribute to longer-term impairments. Here, we employ advanced MRI to investigate skeletal muscle and fascial structural changes during the recovery period of one patient undergoing immobilization after ankle sprains.Material and methodsIn this case study, a participant who suffered an ankle sprain underwent initial MRI scans and, after 21 days (18 of which included immobilization), a follow-up MRI. Techniques used included proton density, 3D stack of spirals, and diffusion tensor imaging to analyse muscle and fascia changes pre- and post-injury.ResultsResults showed muscle atrophy in most shank muscles, with volume loss ranging from no change in the lateral gastrocnemius to 12.11% in the popliteus. Thigh muscles displayed hypertrophy of 6% in the hamstrings, while the quadriceps atrophied by 2.5%. Additionally, fascia thickness increased from 0.94 mm to 1.03 mm. Diffusion tensor imaging indicated that the biceps femoris experienced the most significant changes in physiological cross-sectional area, while the rectus femoris showed minimal change.ConclusionThe findings highlight the variable responses of muscles and a notable thickening of deep fascia post-injury, underscoring its role in recovery from ankle sprains.

Degloving Injury of the Thigh: A Case Report

Background: Morel-Lavallee lesions (MLLs), also known as degloving injuries, are uncommon traumatic soft tissue injuries resulting from the separation of the superficial fascia from the deep fascia, typically due to high-energy trauma or shear forces. This separation leads to fluid accumulation and disruption of skin vascularity, placing the overlying skin at risk for necrosis and infection. MLLs can mimic other soft tissue injuries, such as hematomas, and are often associated with delayed diagnosis and treatment. Case Presentation: A 46-year-old man presented with left thigh swelling persisting for three weeks following a motorcycle crash. Initial imaging with X-rays revealed no fractures, and point-of-care ultrasound identified a large encapsulated fluid collection consistent with MLL. Subsequent computed tomography angiography ruled out vascular injury and confirmed a subcutaneous fluid collection measuring 10.6 cm × 32.0 cm. Conservative management, including compression bandaging and prophylactic antibiotics, was initially recommended; however, after surgical review, ultrasound-guided drainage was performed to mitigate the risk of skin necrosis. The patient recovered uneventfully and was discharged 48 hours after the procedure. Conclusion: This case highlights the importance of maintaining a high index of suspicion for MLLs in patients with post-traumatic swelling, even in the absence of fractures or significant injuries. Accurate diagnosis and timely intervention are essential to reduce the risk of complications. Point-of-care ultrasound and computed tomography are valuable diagnostic tools in emergency settings, particularly for patients with contraindications to contrast agents. Future guidelines should emphasize clinical vigilance and the role of advanced imaging in managing MLLs effectively.

Computed tomographic features of Morel-Lavallée lesions in 3 cats.

To describe the CT features of Morel-Lavallée lesions (MLLs) and their association with trauma in cats. This study aimed to investigate whether MLL fluid in cats accumulates between the dermis and deep fascia near superficial trauma, exhibits a vertical attenuation gradient, and shows no or only mild contrast enhancement on CT images. 3 young cats: a 1-year-old neutered male domestic shorthair cat, a 2-year-old neutered male domestic shorthair cat, and a 3-year-old neutered female British Shorthair cat. The clinical presentation of the 3 cats in the study involved recurrent swelling and fluid accumulation affecting at least 1 pelvic limb following trauma. In all cases, there was a fluid-filled space deep to the skin and superficial subcutaneous layer but superficial to the deep fascial plane overlying the muscular component of the pelvic limbs. The MLL fluid had a vertical attenuation gradient and no or only mild contrast enhancement. Morel-Lavallée lesions are often initially overlooked, likely due to distraction by concomitant significant bone injuries, and can be mistaken for hematomas, seromas, subcutaneous edema, contusions, or cellulitis, leading to less aggressive treatment. If left untreated, MLLs present a significant risk of extensive skin necrosis compared to other types of subcutaneous swelling.

Effects of a 12-week Baduanjin regimen on biomechanical properties of axial muscle fascia in ankylosing spondylitis

Background: This study aims to evaluate the effects of a 12-week Baduanjin regimen on the biomechanical properties of axial muscle fascia in patients with ankylosing spondylitis (AS) through a randomized controlled trial, and to explore the underlying mechanisms of Baduanjin in AS treatment. Methods: Thirty patients with AS were randomly assigned to either the Baduanjin intervention group or the nonintervention group, with 15 patients in each group. The intervention group underwent a 12-week Baduanjin fitness program, while the nonintervention group continued their usual lifestyle and medication. Biomechanical parameters of muscle fascia, including muscle stiffness (N/m), muscle tension (frequency, Hz), and muscle elasticity (logarithmic decrement of oscillation amplitude), were measured at specified spinal locations using the MyotonPRO® soft tissue tester at baseline (week 0) and after 12 weeks (week 12). Results: The Baduanjin group exhibited significant improvements in muscle fascia stiffness, tension, and elasticity in the lumbar and cervical spine compared to the nonintervention group, with notable differences in lumbar stiffness and tension (P < .05). Postintervention, lumbar stiffness and tension were significantly reduced, and elasticity increased in the Baduanjin group, indicating beneficial effects on the biomechanical properties of axial muscle fascia in AS patients. No significant changes were observed in the nonintervention group. The Baduanjin group reported only mild muscle pain initially, which resolved with appropriate management, with no serious adverse effects noted. Conclusion: The findings suggest that Baduanjin significantly enhances the biomechanical properties of axial muscle fascia in AS patients. By improving these properties, Baduanjin may reduce mechanical stress, alleviate micro-damage and inflammation at attachment points, regulate downstream signaling pathways, and potentially limit new bone formation. This study provides scientific support for the use of Baduanjin in managing AS and offers a foundation for future research.

Necrotizing Fasciitis with Vulvar Origin: About an Observation

Necrotizing fasciitis is a rapidly spreading soft tissue infection characterized by extensive necrosis of the deep and superficial fascia. It is a polymicrobial infection in approximately 70% of cases. The infection is serious and fatal due to decompensation of underlying defects and septic shock. The occurrence of this clinical entity in healthy subjects is rare. We report through this observation a case of necrotizing fasciitis with vulvar origin in a 76-year-old patient with a serious medical history.

Acute effect of instrument-assisted soft tissue mobilization on hamstring flexibility via fascial chain

BackgroundSoft tissue techniques are frequently used to treat musculoskeletal disorders. Releasing the muscles through intervention from remote areas is especially important in cases where the muscles are sensitive, inaccessible or cannot be positioned appropriately. This study aimed to examine the effect of instrument-assisted soft tissue mobilization (IASTM) on hamstring flexibility via the fascial chain.Methods35 healthy individuals were included in the study. Straight leg raise (SLR) and popliteal angle (PA) measurements were performed to measure hamstring flexibility. IASTM was applied to the triceps surae muscle and plantar fascia on the non-dominant sides of the participants. The non-dominant legs of the individuals constituted the intervention group, while no intervention was applied to their dominant legs, designated as the control group.ResultsEach group significantly differed in the SLR and PA before and after intervention (p < 0.001, p < 0.001). There was no difference in SLR and PA between groups at the beginning and end (p > 0.05). There was no difference between the groups regarding the SLR and PA measurement changes from baseline to post-intervention (p = 0.583, p = 0.892).ConclusionsAccording to the current study results, a single session of IASTM applied to remote areas does not increase hamstring flexibility.Trial registrationClinicalTrials.gov NCT05750550, Date: 19/02/2023.

Ultrasound Examination of Skin, Fasciae and Subcutaneous Tissue: Optimizing Rehabilitation for Secondary Upper Limb Lymphedema.

Lymphedema represents a frequent cause of disability for patients undergoing oncological treatments and, being a chronic, non-reversible pathology, requires targeted and continuous rehabilitation treatments. To date, the studies available on the use of ultrasound in patients with lymphedema mainly report descriptive data; therefore, with this study, we wanted to describe in a more objective way the typical ultrasound alterations found in these patients, measuring the thickness of the different superficial structures, and defining subcutis echogenicity. 14 patients affected by secondary lymphedema of the upper limbs were enrolled in this cross-sectional observational study (12 had breast cancer and 2 with melanoma as their primary diagnosis). All patients were classified as stage II according to the ISL classification. Patients were examined between March and July 2023 with a clinical and an ultrasound evaluation. Ultrasound evaluation was performed following a protocol and took into consideration thickness of the cutis, subcutis, superficial and deep fascia, and subcutis echogenicity. The cutis of the affected limbs was thicker in the distal anterior region of the arm and throughout the anterior region of the forearm. The subcutaneous tissue was thicker in the posterior region of the distal arm and throughout the forearm, including the dorsum of the hand and excluding only the proximal posterior region of the forearm. Fascial structures did not demonstrate statistically significant differences in thickness between pathological and healthy limbs, despite undergoing significant changes from a qualitative point of view (loss of the trilaminar skin appearance and the development of anechoic areas due to fluid accumulation around the hyperechoic adipose lobule). A statistically significant difference in the echogenicity of subcutaneous tissue was found at the distal anterior region of the arm and at the entire anterior forearm. High-resolution ultrasound has been confirmed to be a tool capable of supporting the diagnosis of lymphedema and identifying the most compromised regions of the limb. A tailored rehabilitation plan can be developed based on the non-uniform alterations in subcutaneous tissue, where some areas are affected earlier than others. This compartmentalization should be considered in lymphedema staging and management. Ultrasound may provide early detection of these changes, guiding a more precise therapeutic approach.

Diagnostic performance of ultrasound for myositis and fasciitis, including necrotizing fasciitis, in pediatric patients.

To demonstrate the diagnostic performance of ultrasound for abnormal magnetic resonance imaging findings in pediatric patients with suspected myositis and fasciitis. We compared sonographic findings between patients with and without necrotizing fasciitis. In 21 pediatric patients, the presence or absence of abnormal T2-high signal intensity in subcutaneous fat, peripheral deep fascia, intermuscular fascia, and muscle was recorded. The extent of the disease based on ultrasound findings was recorded according to the previous locations. The vascular lumen within the affected muscle was also evaluated. Patients were classified into two groups: those with necrotizing fasciitis and those without. The presence/absence of sonographic findings and width of fluid accumulation in the peripheral deep fascia was compared between the two groups. Three patients were classified into the necrotizing fasciitis group. The ultrasound diagnostic performance for abnormal findings in subcutaneous fat/peripheral deep fascia/ intermuscular fascia/muscle was 90.5%/76.2%/47.6%/90.5%, respectively. The presence/absence of abnormal findings in peripheral deep fascial edema, its width and vascular lumen collapse were significantly different between the two groups. The other findings were not significantly different between the groups. Ultrasound demonstrated reliability in detecting abnormal findings and was useful for diagnosing necrotizing fasciitis, facilitating urgent surgical intervention.

Reconstruction de l’aponévrose musculaire de la zone donneuse du lambeau antérolatéral de cuisse par plaque synthétique : technique et bénéfice

The anterolateral thigh flap is sometimes harvested with a portion of the quadriceps muscle fascia, which can lead to muscle hernias or adhesions at the donor site. Studies report an 11 to 32% incidence of muscle hernias and an 8 to 26% incidence of persistent weakness at the donor site. There is no data in the scientific literature presenting a surgical technique for the prevention of muscle hernias at the donor site of the anterolateral thigh flap. The objective of our study is to describe our technique for placing a synthetic mesh when closure of the fascia is not possible during the harvesting of an anterolateral thigh flap, in order to reduce the risk of postoperative muscle hernias and to analyze its benefits. As part of a prospective study, we present here our technique for reconstructing the fascia by placing a non-resorbable synthetic mesh. Twenty-two patients underwent the placement of a mesh for the reconstruction of the fascial defect, which averaged 9.6cm. One year after the procedure, none of the patients presented with a muscle hernia or adhesions at the donor site. According to studies, muscle hernias and scar adhesions occur in 11 to 32% of cases and are both unsightly and disabling for patients. Although it is difficult to quantify the benefit in terms of muscle strength, fascia reconstruction effectively prevents this type of complication. When the defect is greater than 8cm, we believe it is essential to reconstruct the fascia during harvesting to prevent the occurrence of hernia or adhesion at the donor site. While not affecting limb function, muscle hernia is at least aesthetically bothersome and should be systematically prevented. Reconstruction of the muscle fascia at the donor site of the anterolateral thigh flap with a non-resorbable synthetic mesh, in cases of a defect greater than 8cm, prevents the occurrence of muscle hernias and adhesions, which can lead to aesthetic and functional complications.

Temporal Incision Super-high Superficial Musculoaponeurotic System Face Lift for Chinese Patients.

This investigation assessed patient satisfaction with a temporal incision technique using a super-high superficial musculoaponeurotic system (SMAS) flap for midface lifting in a Chinese patient cohort. From July 2019 to July 2023, 95 patients underwent midface lifts via a temporal incision approach at our institution. The extent of SMAS flap dissection spanned 2 cm above the outer canthus, to the lower margin of the zygomatic arch inferiorly, and medially to the zygomaticus major muscle. The technique involved anchoring the elevated SMAS flap to the deep temporal fascia to elevate the malar fat pads, correct sagging tissues, and ameliorate the appearance of nasolabial folds. Among the 95 patients, 61 completed a follow-up ranging from 6 months to 2 years postsurgery, with a majority reporting satisfaction with the aesthetic results of their midface lift. No significant complications, including permanent facial nerve injury, were reported. The temporal incision super-high SMAS face lift technique demonstrated high patient satisfaction and clinical effectiveness in improving the appearance of nasolabial fold and midface aesthetics. However, the success of this technique hinges on a comprehensive understanding of facial anatomy due to the confined operative field, highlighting its technical demands and the need for surgical expertise.

A new and simplified extraoral approach for inferior alveolar nerve block: a cadaveric study and clinical case reports.

Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the "inferior alveolar nerve block mandibular angle approach (IANB-MA)," using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported. We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection. Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6mL and 8mL). The pterygomandibular space was filled with 6mL and 8mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain. The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.

Role of trigeminal ganglion satellite glial cells in masseter muscle pain hypersensitivity.

The underlying mechanism of masseter muscle pain hypersensitivity by sustained masseter muscle contraction (SMMC) is not well understood. This study aimed to examine whether the activation of satellite glial cells in the trigeminal ganglion (TG) contributes to masseter muscle pain hypersensitivity induced by SMMC. Electrodes were placed on the masseter muscle fascia of rats to induce strong contractions, by daily electrical stimulation. Pain sensitivity in the masseter muscle was measured and the activation level of satellite glial cells in the TG was examined. The localization of P2Y12 and the effects of P2Y12 receptor inhibition on SMMC-induced pain hypersensitivity were evaluated. The amount of tumor necrosis factor alpha (TNF-α) and TNF-α receptor localization were determined in the TG. SMMC induced masseter muscle pain hypersensitivity and activation of satellite glial cells. P2Y12 receptors were expressed in satellite glial cells and masseter muscle pain hypersensitivity was suppressed by intra-TG P2Y12 receptor antagonism. TG neurons innervating the sustained-contracted masseter muscle expressed TNF-α receptor and SMMC increased TNF-α levels in TG. SMMC-induced activation of satellite glial cells though the P2Y12 receptor signaling may contribute to masseter muscle pain hypersensitivity via the TNF-α signaling pathway.

Ultrasound Imaging of the Superficial and Deep Fasciae Thickness of Upper Limbs in Lymphedema Patients Versus Healthy Subjects.

Lymphedema, a common source of disability among oncology patients, necessitates continuous targeted rehabilitation. Recent studies have revealed the role of connective tissue in this pathology; however, despite existing research on ultrasound (US) use in lymphedema, no studies have specifically addressed the use of ultrasound to assess fasciae in patients with lymphedema. This study aims to provide a more objective characterization of typical US alterations in these patients by quantifying the thickness of superficial and deep fasciae and comparing them with those of healthy volunteers. A cross-sectional study was performed using US imaging to measure the thickness of superficial and deep fascia in different regions and levels of the arm and forearm in a sample of 50 subjects: 25 chronic lymphedema patients and 25 healthy participants. No significant difference in fascial thickness was observed between affected and unaffected upper limbs, but patients had notably thinner superficial fascia and deep fascia compared with healthy volunteers. The findings for superficial and deep fascia revealed statistically significant differences (p < 0.0001) in all regions and levels. This study demonstrates the effectiveness of US imaging as a non-invasive tool for detecting subtle fascial changes in chronic lymphedema patients, revealing thinner fasciae compared with those in healthy volunteers. These findings suggest a potential anatomical predisposition to lymphedema, highlighting the importance of incorporating detailed US assessments in diagnosis and management to improve early intervention and patient outcomes. Future studies could, therefore, investigate whether preventive fascia assessment might improve the early identification of individuals at risk.

AUTOMATIC ASSESSMENT OF OCT SKIN THICKNESS IN MICE BASED ON TRANSFER LEARNING AND ATTENTION MECHANISMS

Optical coherence tomography (OCT) is characterized by high resolution and noninvasiveness; thus, it has been widely used to analyze skin tissues in recent years. Previous studies have evaluated skin OCT images using traditional algorithms with low accuracy for complex tissue structure images. Although a few studies have used deep learning methods to assess tissue structure in OCT images, they lack quantitative assessment of deeper skin tissue thickness and are limited to the epidermal layer. Thus, in the present study, we proposed an automated segmentation and quantitative evaluation method. The skin OCT images were first pre-processed, and the attention mechanism was added to U-Net based on transfer learning to segment the images and quantify the thickness of mouse skin tissue structure. The results showed that U-Net combined with the coordinate attention (CA) mechanism had better segmentation performance with 93.94% mean intersection of union (MIoU) value and 96.99% Dice similarity coefficient; the segmentation errors were 0.6 μm, 2.2 μm, 3.8 μm, and 6.0 μm for the epidermis layer, subcutaneous fat layer, muscle fascia layer, and the overall skin tissue structure of mice, respectively. The overall skin tissue thickness of the four mice were 235 ± 20 μm, 264 ± 42 μm, 275 ± 40 μm, and 774 ± 91 μm, respectively. The present study provides a rapid and accurate method for the automated measurement of skin tissue thickness.

Ultrasound Imaging Comparison of Crural Fascia Thickness and Muscle Stiffness in Stroke Patients with Spasticity.

Spasticity following stroke causes structural changes in the muscles and fascia, affecting the mobility and functional recovery of patients. Understanding these structural changes is critical to optimizing the rehabilitation strategies for patients. Therefore, in this study, we aimed to investigate the differences in crural and epimysial fascia thickness and muscle stiffness in the affected and unaffected lower limbs of chronic stroke patients with spasticity. A total of 88 patients with chronic stroke (mean age: 62.7 ± 10.2 years) were included in this study. Ankle range of motion, crural fascial thickness, and muscle stiffness in affected and unaffected lower limbs were assessed using ultrasound. For the affected lower limbs, 59 patients (67.1%) exhibited a modified Ashworth scale score of 2, whereas 29 patients (32.9%) exhibited a score of 3. Ankle range of motion, fascia thickness, and muscle stiffness were also measured. The range of motion in ankle dorsiflexion and plantar flexion was significantly reduced on the affected side (p < 0.05). Crural fascia thickness was significantly greater in all regions of the affected side (anterior: 0.96 ± 0.14 vs. 0.72 ± 0.08 mm [p < 0.001]; lateral: 1.01 ± 0.14 vs. 0.75 ± 0.14 mm [p < 0.001]), and the epimysial fascia of the tibialis anterior muscle was similarly greater in the affected side (0.46 ± 0.07 vs. 0.34 ± 0.03 mm [p < 0.001]). However, no significant differences in muscle stiffness were observed between the affected and unaffected sides (p > 0.05). Overall, these findings revealed significant fascial thickening with only minimal changes in muscle stiffness on the affected side, highlighting the importance of controlling fascial changes for post-stroke spasticity management.

Ultrasound assessment of muscle and fascia properties and the effects of spasticity and botulinum toxin injections on spastic muscles in chronic stroke survivors.

To objectively quantify changes in muscle properties in chronic stroke survivors and the effects of spasticity and botulinum toxin injections (BoNTi) on muscle properties using ultrasonography. In this cross-sectional observational study, 24 stroke subjects with history of BoNTi to biceps brachii muscles (BB) but without BoNTi to the triceps (TRI) were included. 12 subjects had spastic TRI, the other half did not. 20 subjects had spasticity in wrist flexors, and 11 subjects received BoNTi to the flexor carpii ulnaris (FCU). On average, a significant decrease in muscle thickness (16.5% loss in TRI), a thicker fascia with higher echo intensity were noted on muscles in the paretic limb. Percent muscle loss (PML) was significantly less (11.0%) in spastic TRI than in non-spastic TRI (22.1%). There was no statistically significant difference in muscle and fascia properties in spastic FCU with and without BoNTi. Spasticity did not correlate significantly with muscle loss, fascia thickness or echo intensity. Our results provided evidence that muscles on the spastic-paretic side had less muscle mass, thicker fascia and greater echo intensity. Our results showed that spasticity helped maintain muscle mass, but failed to reveal additional muscle loss after botulinum toxin injection.