Classification of Hypertrophic Gastrocnemius Muscle and Its Treatment with Botulinum Toxin A

The Effect of Calf Subcutaneous Fat Thickness on Patient Satisfaction after Calf Contouring with Botulinum Toxin A

BACKGROUND

As a minimally invasive therapy, botulinum toxin A (BTXA) treatment effectively reduces the hypertrophy of the gastrocnemius muscle (GM). Patient satisfaction is, however, reported to be low after treatment, with a possible correlation between high satisfaction and thinner subcutaneous fat. The goal of this study was to classify the subcutaneous fat of calves to understand the relation between fat thickness and patient satisfaction after BTXA treatment.

METHODS

The maximal leg circumference was measured, and B-mode ultrasound was used to measure the thickness of the medial head of the GM and of the subcutaneous fat. Patients were followed up at 1 and 6 months after BTXA treatment.

RESULTS

A total of 50 cases were classified into the following levels of fat thickness: slim (<0.55 cm), moderate (0.55 to 0.85 cm), and bulge (>0.85 cm). All patients were treated with 300 units of BTXA. Patients in the slim and bulge groups reported higher satisfaction rate than patients in the moderate group, with patients in the slim and bulge groups reporting complete satisfaction (100%) with calf contour at the 6-month follow-up. The satisfaction rate with the improvement in total leg circumference was low in all 3 groups. No severe complications were encountered in this study.

CONCLUSIONS

This study identified a U-shaped correlation between calf subcutaneous fat thickness and patient satisfaction rate after treatment. The authors' results provide a theoretical basis for BTXA treatment and suggest the importance of preprocedure conversations in GM hypertrophy treatment.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

The Efficacy of Botulinum Toxin A Injection for Gastrocnemius Hypertrophy: A Prospective, Randomized, Double-blinded Controlled Trial

Background

Many individuals hold an interest in aesthetic appeal, with one aspect of physical attractiveness being the alluring contour of the lower leg. Utilizing botulinum toxin A (BTX-A) injections offers several advantages, including a short procedure time, low pain, and a speedy recovery. With a demand for high-level evidence regarding the effectiveness of BTX-A injections for correction of lower leg contour, we evaluated the safety and efficacy of BTX-A injection for improvement of gastrocnemius muscle hypertrophy.

Methods

We conducted a prospective, randomized, and controlled clinical trial to evaluate whether the injection of BTX-A into the gastrocnemius muscle could decrease muscular hypertrophy. The patients were randomized into a low-dose injection (60 units) group and a high-dose injection group (100 units) for each leg. Demographics, clinical outcome, and satisfaction score were compared between the two groups.

Results

A total of 20 patients and 40 legs were enrolled in this study. Clinical and surgical demographics were similar between the two groups. BTX-A injection showed a significant decrease in the circumference of the calf after 8 weeks (preinjection: 36.35 ± 0.63 cm versus postinjection: 35.87 ± 0.61 cm; P = 0.03). However, no significant difference was observed between the low- and the high-dose group (-0.52 ± 0.74 cm versus -0.44 ± 1.04 cm, P = 0.78).

Conclusions

BTX-A injection can be a good noninvasive method for the correction of hypertrophic gastrocnemius muscles. This study supports the use of BTX-A injections in patients unsatisfied with lower leg hypertrophy.

Botulinum Toxin Treatment for Calf Contouring Based on the Study of Combined Injection of Gastrocnemius and Soleus

BACKGROUND

Botulinum toxin is administered to paralyze the gastrocnemius muscle and reduce its size, thereby improving the calf contour and reducing the leg circumference of the calf.

OBJECTIVES

In pursuit of better efficacy, we designed a new injection protocol that targeted both the gastrocnemius and soleus. An algorithm of botulinum toxin injection for calf contouring was proposed based on the results of the study and ultrasonographic data.

METHODS

A prospective, self-controlled, double-blind study was conducted. The gastronemius muscle (GM) group (n = 17) included the patients whose gastrocnemius muscles were treated, and the GM + soleus muscle (SM) group (n = 17) included the patients who had both the gastrocnemius and soleus treated. Parameters including the maximum leg circumference and the subcutaneous fat, gastrocnemius muscle, and soleus muscle thicknesses were collected before and after injection.

RESULTS

Both GM and GM + SM injection helped improve calf contour. Although the thickness of the gastrocnemius muscle was reduced, reducing the leg circumference, the subcutaneous fat and soleus muscle had compensatory thickening after injection, especially over the long term, which may affect the efficacy. Compared with the GM group, the GM + SM group effectively reduced the tendency of the soleus muscle to thicken. Calf muscle thickness could be roughly estimated by constructing a fitting equation and measuring height, weight, and leg circumference.

CONCLUSIONS

Two injection methods achieved the effect of improving calf contour and reducing the leg circumference with equivalent patient satisfaction. The GM + SM injection group did not show any obvious extra clinical benefit when compared with the GM injection group.

LEVEL OF EVIDENCE: 2

Pulmonary Embolism after Botulinum Toxin Treatment for Leg Muscle Hypertrophy

Leg muscle hypertrophy is a unique physical symptom in East Asian women. Compared with traditional surgical treatment for calf muscle hypertrophy, botulinum toxin is widely favored by East Asian women because of its minimal trauma and significant effects. We describe the case of a 22-year-old woman with pulmonary embolism because of deep vein thrombosis, who presented with hypertrophy of bilateral calf muscles, and was administered 300 U of botulinum toxin A injection in July 2022. On the third day after the injection, she experienced swelling and pain in her left leg, which gradually worsened and made walking difficult. She underwent an ultrasound examination of lower limbs, which revealed several deep and shallow vein thrombi in the left lower limb. Computed tomography arterial imaging indicated multiple embolisms in pulmonary arteries. This study aimed to explore and analyze the causes of pulmonary embolism after botulinum toxin treatment for calf muscle hypertrophy by reviewing and analyzing the patient's symptoms, diagnosis, and treatment process to provide management strategies for treatment and prevention of this disease.

Classification of gastrocnemius muscle hypertrophy for personalized botulinum toxin type A treatment

BACKGROUND

Owing to its safety and convenience, botulinum toxin type A (BoNtA) has become a first-choice treatment for contouring calf muscle asymmetries or deformities. Different injection methods and dosages have been discussed in the literature, but a standardized BoNtA treatment remains unclear.

AIMS

This study aimed to classify gastrocnemius muscle hypertrophy (GMH) through multiple measurements to provide a personalized BoNtA treatment protocol.

METHODS

The measurements combining of gastrocnemius muscle (GM) contour, max leg circumference and GM thickness was applied to classify different type of GMH in a normal population. Based on these findings, a personalized BoNtA treatment protocol was determined and evaluated regarding max leg circumference, GM thickness, the position of max leg circumference, patient and doctor satisfaction rate, and complications.

RESULTS

A total of 100 GMH were classified into two bulging types (bilateral-bulging type and unilateral-bulging type) and two categories (moderate GMH and severe GMH). 40 cases were treated with personalized BoNtA injection methods ("Even" or "Intense"method) and dosages (300 or 400 units). Follow-up examinations at 1, 3, and 6 months after treatment. Max leg circumference and GM thickness decreased significantly and the position of max leg circumference rose prominently during treatment (2.56± 1.93; p< 0.05). The overall patient satisfaction rate was 70%-100%. No serious complications occurred.

CONCLUSIONS

We identify four groups of GMH through several measurements and outline a personalized BoNtA treatment for each type. This recommended protocol may improve the therapeutic outcomes and patient satisfaction after treatment.

Selective Neurocoagulation of Gastrocnemius and Lateral Soleus Muscles for Calf Reduction

BACKGROUND

Various methods have been attempted to improve the size and shape of calves, and selective neurocoagulation of the calf muscle using radio frequency (RF) is one of them. The objective of this study was to provide information about the efficacy and safety of selective neurocoagulation of the gastrocnemius (GCM) and lateral soleus muscles using RF for cosmetic purposes.

METHODS

A retrospective analysis of 345 patients (686 legs), who underwent selective neurocoagulation using RF at our clinic for calf hypertrophy between January 2018 and March 2020, was performed. We measured the circumference of the calf and thickness of the medial GCM using ultrasonography before and after the procedure. Patient satisfaction and side effects were investigated through interviews.

RESULTS

The average calf circumference had decreased by 2.9 ± 1.1 cm (GCM-only group) and 3.0 ± 1.4 cm (GCM + lateral soleus group), at 6 months after the procedure, and there was a statistically significant decrease in both groups. At 12 months after the procedure, the calf circumference slightly increased compared to that at 6 months, but the circumference was still smaller than that before the procedure. Most patients were satisfied with the size and contour of their calves and there were no severe adverse effects.

CONCLUSIONS

Motor nerve coagulation using RF was effective in reducing the volume of the GCM and lateral soleus muscles and softening the contours of the calf. It was safe and without side effects in most patients.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Ultrasonographic analysis of the calves for efficient botulinum toxin type A injection

BACKGROUND

Large calves are considered unattractive. Botulinum toxin type A (BoNT-A), acting as a neurotoxin that reduces muscle contraction, is widely used in calf contouring. However, there lacks detailed anatomical data to guide clinical injection.

OBJECTIVES

This study aims to use ultrasonography to provide depth information of the calf muscles and determine the morphological types of the gastrocnemius muscle.

METHODS

Ultrasound scanning was performed at six sites on 40 Chinese adults. A real-time ultrasound scannerwas used to detect the depth of the gastrocnemius muscle and the soleus muscle.

RESULTS

The thickness of the gastrocnemius muscle and the soleus muscle was measured. The depth from the skin to the surface, the middle, and the bottom of the gastrocnemius muscle was measured. The morphology of gastrocnemius muscle was classified into four different types under ultrasound according to the muscle bulge pattern.

CONCLUSION

This study took ultrasonic measurements of Asian calves to guide accurate and effective BoNT-A injection in real clinical practice.

Temporary Botulinum Immobilization of Residuum Muscles for Facilitation of the Initial Ingrowth of Skin to the Porous Skin and Bone Integrated Pylon in the Technology of Direct Skeletal Attachment: Large Animal Model

Enhancing the technology of bone-anchored limb prosthetics, we present a modified porcine model for developing an infection-free integration between the skin and a percutaneous bone implant. The deeply porous Skin and Bone Integrated Pylon (SBIP) presented an infection-free skin-implant interface both after implantation into the dorsum and after implantation into the residuum after below-knee amputation. However, deep ingrowth of skin into the porous cladding of the SBIP was achieved better in the dorsal procedure, while implantation to the residuum sometimes developed a stoma, probably due to the high mobility of the skin and soft tissues in the pig's thigh. Uncontrolled high skin mobility during the first week after implantation constituted a limitation for the porcine animal model, which we tried to address in the current study. As our previous studies showed that casting of the leg residuum did not sufficiently limit the skin's movement around the implant, we tested a modified protocol of the implantation, which included injection of botulinum toxin into the thigh muscles. During the course of the study, we identified proper botulinum toxin componentry, dosage, and the period after injections to achieve a maximal effect of immobilization of the muscles affecting skin movements. To verify the immobilization, we used kinetic data on the asymmetry of loading during gait with the Strideway System, Tekscan, Inc., Boston, MA, USA. We found that injections in the four muscles of the distal thigh of the left hind leg with MYOBLOC® (rimabotulinumtoxinB; 5,000 units/muscle) were sufficient to provide noticeable immobilization by the fourth week after the procedure. This conclusion was made based on the analysis of the dynamics of asymmetry in vertical ground reactions on the injected (left hind) and uninvolved (right hind) legs during gait over an instrumented walkway.

The "Visible" Muscles on Ultrasound Imaging Make Botulinum Toxin Injection More Precise: A Systematic Review

BACKGROUND

Botulinum toxin (BoNT) injection is the most commonly performed procedure in cosmetic surgery. However, blind injection is unable to take individual anatomical variations into consideration, which is the main contributing factor to complications. Ultrasound (US) imaging was introduced to reduce complications and improve effects. This article will review uses of US in aesthetic BoNT injection.

METHOD

A systematic electronic search was performed using the PubMed, MEDLINE, Web of science. Search terms were set to focus on aesthetic BoNT injection. Two independent reviewers subsequently reviewed the resultant articles based on strict inclusion and exclusion criteria. Selected manuscripts were analysed and grouped by procedure categories. Clinical cases were all performed by one plastic surgeon in our department.

RESULTS

The search finally retained 24 articles. Five procedural categories were identified, including masseter (n = 16), frontalis (n = 2), glabella complex (n = 2), trapezius (n=1), and gastrocnemius (n = 3). US imaging is practical and instructive for pre-operative assessments as in needle-type selection, injection point localization and depth setting, as well as post-operative follow-ups regarding injection feedback (for instance, the extent of muscle volume decreases). What's more, ultrasound-guided injection makes needle trajectory visualized so as for the needle to reach the target muscle in avoidance of potential damage to neurovascular bundle, gland or adjacent muscle.

CONCLUSION

Muscles, such as masseter, frontalis, glabella complex, trapezius and gastrocnemius, and their adjacent structures can be well visualized using US, and as such, US can be a useful tool for a variety of pre-operative, intra-operative and post-operative procedures.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Botulinum toxin type a intralesional monotherapy for treating human hypertrophic scar in a dose-dependent manner: In an animal model

BACKGROUND

The effect of Botulinum toxin type A (BTX-A) in treating or preventing a hypertrophic scar (HS) had been reported in clinical studies. However, the dose-effect relationship remains unclear.

OBJECTIVE

To study the dose-effect relationship of BTX-A intralesional monotherapy treating human HS.

METHODS

Six HS tissues were collected from six patients. Each tissue was segmented into 24 specimens and split into four groups: negative control (group A), 0.5U BTX-A (group B), 1U BTX-A (group C), and 2U BTX-A (group D). Six nude mice, each was prepared by implanting four specimens (one from each group) into the back for a total of 24 specimens. The process mentioned above were repeated six times. A re-entry operation was performed to obtain the specimens after 8 weeks. The weight of HS, the expression of decorin and TGF-β₁, the proliferation, and migration ability of hypertrophic scar fibroblasts (HSFBs) were compared among groups.

RESULTS

The weight of HS, the expression of decorin and TGF-β₁, the proliferation, and migration ability of HSFBs showed significant differences in groups C and D as compared to group A; there has been no statistical significance in group B.

CONCLUSION

BTX-A showed significant therapeutic efficacy when compared with the negative control group in a dose-dependent manner. BTX-A can reduce the weight of HS, upregulate the expression of decorin, downregulate the expression of TGF-β₁, and inhibit HSFBs proliferation and migration ability. This study indicates that BTX-A intralesional monotherapy treating HS should reach a threshold dose to achieve an effective treatment, and a high dose of BTX-A is more effective than a low dose.