Treatment of Gastrocnemius Muscle Hypertrophy with Botulinum Toxin Injection Followed by Magnetic Resonance Imaging Assessment and 3-Dimensional Evaluation

Endoscopic Concurrent Gastrocnemius Muscle Resection and Soleus Muscle Neurectomy for Severe Muscular Calf Hypertrophy

BACKGROUND

Selective neurectomy or muscle resection techniques for calf reduction conventionally focus on the gastrocnemius muscle. However, the underlying soleus muscle plays an important role in muscular calf hypertrophy. In the authors' experience, the results of calf reduction have been suboptimal in patients with severe muscular calf hypertrophy who underwent gastrocnemius muscle resection only. This article describes a new calf reduction method that uses concurrent gastrocnemius muscle resection and soleus muscle neurectomy using an endoscope-assisted single-incision approach in patients with severe muscular calf hypertrophy.

METHODS

A total of 139 patients who underwent simultaneous gastrocnemius muscle resection and soleus muscle neurectomy for severe calf hypertrophy from March of 2017 to June of 2020 were retrospectively analyzed.

RESULTS

After combined gastrocnemius resection (mean weight per calf, 349 g) and soleus neurectomy, about 3.8 to 8.2 cm (mean, 6.4 cm) or 12.8% to 24.3% (mean, 16.6%) of the calf was reduced. Complications included cellulitis, hematoma, seroma, and mild depression ( n = 1 each). Two patients had traction injury to the sural nerve. One patient developed Achilles tendon rupture at 2 months postoperatively. No patient complained of functional impairment with respect to easy fatigability, stability, gait, or sport activities at 6 months postoperatively.

CONCLUSION

This study is the first to combine gastrocnemius muscle resection with selective soleus muscle neurectomy to achieve the most efficient calf reduction for severe muscular calf hypertrophy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Aesthetic Considerations for Neuromodulator Use in Transgender Patients

BACKGROUND

The aesthetic dimension of transgender experiences involves various aspects linked to the visual representation and expression of one's gender identity. Nonsurgical cosmetic procedures, such as neuromodulators, have consequently become a viable treatment option for patients with gender dysphoria because of the ability to yield significant, although temporary, results with minimal associated risks and downtime.

OBJECTIVE

To comprehensively review literature pertaining to the aesthetic considerations for use of neuromodulators in transgender and nonbinary individuals.

MATERIALS AND METHODS

A literature review of PubMed/MEDLINE for studies was published through January 2024 for nonsurgical facial and body modification using neuromodulators. Searches were conducted with relevant keywords. Peer-reviewed articles and their references published within the past 10 years were given emphasis in the review.

RESULTS

Based on the limited publications to date, the authors prepared a comprehensive review on indications for neuromodulator treatment in this population, including brow positioning, lower face contouring, lip eversion, trapezius slimming, and leg contouring.

CONCLUSION

Dermatologists play a crucial role in facilitating the achievement of gender affirmation goals.

Contouring With Neuromodulators

BACKGROUND AND OBJECTIVE

Botulinum toxins, originally used for facial rejuvenation, have emerged as a promising tool for sculpting and refining contours for both the face and body.

METHODS

The peer-reviewed literature on neuromodulator contouring treatments was analyzed, with a particular emphasis on studies and case reports involving the use of botulinum toxin type A.

RESULTS

Modification of face, neck, shoulder, arm, and calf contour has been reported. Treatment and dosing protocols vary with the strength and depth of the target muscle. Regional effects of neuromodulator treatment begin to appear approximately 2 weeks after injection and are often most prominent at the 70- to 90-day time point. Although treatments are generally well tolerated, short-term muscle weakness and other side effects may occur.

CONCLUSION

The use of neuromodulators to enhance facial and body contours has demonstrated efficacy, but further research is needed to validate their use and explore the full potential of this intervention through larger randomized controlled trials. The application of neuromodulators as a minimally invasive tool to address the rising demand for nonsurgical body sculpting represents a promising frontier in aesthetics.

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

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.

Botulinum Toxin A Injection for Hemihypertrophy-related Unilateral Gastrocnemius Hypertrophy

Hemihypertrophy is a rare congenital disorder that causes unequal growth of the extremities, trunk, face, or half of the body. We report a case of a 32-year-old woman with hemihypertrophy-related gastrocnemius hypertrophy treated with botulinum toxin A injection. The patient has received two botulinum toxin A injections, and we measured the thickness of the gastrocnemius muscle using ultrasound and measured the maximum circumference around the calf with the patient in the prone position. The patient's maximum calf circumference was reduced by 1 cm. The thickness of the medial head of the gastrocnemius was reduced by 0.3 cm, and the thickness of the lateral head of the gastrocnemius was reduced by 0.6 cm. Botulinum toxin A injection therapy was effective in treating hemihypertrophy-related gastrocnemius hypertrophy.

A Double-Blinded, Randomized, Dose-Comparison Pilot Study to Comparatively Evaluate Efficacy and Safety of Two Doses of Botulinum Toxin Type A Injection for Deltoid Muscle Hypertrophy

BACKGROUND

Botulinum toxin type A (BTX-A) injection is being widely used off-label for muscular hypertrophy, including deltoid muscle hypertrophy. However, very few studies have evaluated the optimal dosage and its clinical response.

OBJECTIVE

This study aimed to assess the efficacy and safety of different doses of Prabotulinum toxin A (PBoNT) for treating deltoid muscle hypertrophy.

METHODS

Twelve particiapants with bilateral deltoid muscle hypertrophy were enrolled and randomly received either 16 U or 32 U of PBoNT. In each participant, the same dose was administered to both deltoid muscles. Both participants and evaluators were blinded. Deltoid muscle thickness and upper arm circumference were measured on day 0, and weeks 2, 4, and 12 after the PBoNT injection.

RESULTS

Upper arm circumference significantly decreased in both groups; however, deltoid muscle thickness was reduced in the 16 U group only. No major complications were reported in both groups. However, a few minor complications were reported in the 16 U injection group.

CONCLUSION

Both 16 U and 32 U of PBoNT intramuscular injections are safe and effective in treating deltoid hypertrophy.

Intramuscular Neural Distribution of the Gastrocnemius for Botulinum Neurotoxin Injection: Application to Cosmetic Calf Shaping

PURPOSE

Anatomical landmarks can provide vital information on the distribution of nerves in the gastrocnemius muscle. We aimed to provide an anatomical perspective on appropriate locations for botulinum neurotoxin (BoNT) injections in the medial and lateral parts of the gastrocnemius for calf shaping.

MATERIALS AND METHODS

A modified Sihler's method was applied to both the medial and lateral parts of the gastrocnemius muscles (16 specimens). Intramuscular neural distributions were revealed by dissecting along a transverse line crossing the fibular head and superior margin of the calcaneal tuberosity.

RESULTS

The intramuscular neural distribution for the medial and lateral parts of the gastrocnemius had the greatest arborized patterns in the 7/10-8/10 section of the medial head and 7.5/10-8.5/10 section of the lateral part of the gastrocnemius.

CONCLUSION

We propose that BoNT injections should be directed to the 7/10-8/10 section of the medial head and the 7.5/10-8.5/10 section of the lateral part of the gastrocnemius. Following our guidelines, clinicians can ensure satisfactory results with the use of minimal doses to limit adverse effects, such as gait disturbance, antibody production, and bruising, due to multiple injections. The results can also be altered and applied to electromyography.

Techniques and Applications of Lower Extremity Feminization and Masculinization

Background

Significant differences exist between feminine and masculine lower extremities, and this region contributes to gender dysphoria in transgender and nonbinary individuals.

Methods

A systematic review was conducted for primary literature on lower extremity (LE) gender affirmation techniques as well as anthropometric differences between male and female lower extremities, which could guide surgical planning. Multiple databases were searched for articles before June 2, 2021 using Medical Subject Headings. Data on techniques, outcomes, complications, and anthropometrics were collected.

Results

A total of 852 unique articles were identified: 17 met criteria for male and female anthropometrics and 1 met criteria for LE surgical techniques potentially applicable to gender affirmation. None met criteria for LE gender affirmation techniques specifically. Therefore, this review was expanded to discuss surgical techniques for the LE, targeting masculine and feminine anthropometric ideals. LE masculinization can target feminine qualities, such as mid-lateral gluteal fullness and excess subcutaneous fat in the thigh and hips. Feminization can target masculine qualities like a low waist-to-hip ratio, mid-lateral gluteal concavity, calf hypertrophy, and body hair. Cultural differences and patient body habitus, which influence what is considered "ideal" for both sexes, should be discussed. Applicable techniques include hormone therapy, lipo-contouring, fat grafting, implant placement, and botulinum toxin injection, among others.

Conclusions

Due to lack of existing outcomes-based literature, gender affirmation of the lower extremities will rely on application of an array of existing plastic surgery techniques. However, quality outcomes data for these procedures is required to determine best practices.

Simultaneous calf reduction and contouring with customized differential subtotal gastrocnemius resection and muscle transposition: Analysis of 200 cases

BACKGROUND

Oversized muscular calves can cause severe emotional distress. Total, partial, and subtotal resections of the gastrocnemius muscle for calf reduction have been described. However, the amount of muscle resected may be inappropriate, and the resultant leg contour may not be straight or esthetically pleasing enough.

OBJECTIVES

This study aimed to describe a technique of customized differential subtotal gastrocnemius resection and muscle transposition.

METHODS

A total of 200 patients who underwent customized differential subtotal gastrocnemius resection and muscle transposition for hypertrophic muscular calves from July 2013 to June 2016 were included in the study.

RESULTS

A total of 148 patients underwent subtotal resection of both heads, and calf reduction ranged from 3.2 to 7.2 cm (mean 14.8%). Forty-two patients underwent subtotal resection of the medial head alone, and calf reduction ranged from 2.8 to 5.5 cm (mean 9.2%). Ten patients underwent subtotal resection of the lateral head alone, and calf reduction ranged from 1.2 to 2.1 cm (mean 4.6%). The medial gastrocnemius muscle was subtotally resected in 190 (95%) patients. In 130 (65%) patients, the preserved medial gastrocnemius muscle was transposed superomedially to achieve a straighter medial contour. None of the patients complained that their legs were too thin because of over-reduction. Cybex test showed that near-total muscle strength recovery was achieved within 6 months.

CONCLUSION

Customized differential subtotal gastrocnemius resection together with muscle transposition resulted in enhanced calf reduction with straighter leg contour, without any impairment of the leg function. This approach may be more appealing to both patients and surgeons.

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.

Medial gastrocnemius resection for calf reduction by using a popliteal mini-incisional approach in Asians

BACKGROUND

To create a new approach of resecting medial gastrocnemius for calf reduction and to meet the increasing requirement of the beauty standard of calf sliming in Asian.

METHODS

Twenty patients with 39 calves underwent gastrocnemius resection for calf reduction. Under general anesthesia, a 5 cm incision, along the popliteal crease, was made down to the sub-popliteal deep fascia on a prone position. The medial belly of the gastrocnemius muscle was then dissected, in a blunt way, from the popliteal fossa down to the Achilles tendon around the muscular belly when its neurovascular bundle was ligated and cut off. Thereafter, the medial gastrocnemius was pulled out of the wound and incised transversely off at the level of the popliteal fossa while the attachment to the Achilles was transected with a long rectangular scissors. The incisional wound was finally closed in layers.

RESULTS

Twenty patients with 39 calves were treated using the above-mentioned technique without severe complications. The harvested gastrocnemius muscle weighed 192.1 g in mean (from 104.5 g to 307.6 g). The calf circumference was significantly decreased from 36.3 cm in mean to 32.8 cm in mean before and after the operation (p <0.05).

CONCLUSIONS

The above-mentioned technique may be a safer, simpler, and more efficient method for calf reduction with less morbidity of the potential complications, in comparison with the traditional techniques.

Emerging off-label esthetic uses of botulinum toxin in dermatology

Botulinum toxin is a neurotoxic protein produced by Clostridium botulinum, the bacterium responsible for botulism. Botulinum toxin was first used for therapeutic indications in the 1970s for the treatment of strabismus. With greater understanding of its underlying physiology and safety profile, the use of botulinum toxin has now expanded to a range of cosmetic and medical indications. We performed a systematic review of current literature on the applications of botulinum toxin on off-label esthetic uses. Electronic databases were searched for original published studies including randomized trials, observational or cohort studies, as well as relevant case reports. To add to the body of evidence, our review summarizes and synthesizes key study characteristics, results, and level of evidence for each use case. Although the body of evidence remains weak, there is increasing support for the use of botulinum toxin in emerging off-label esthetic uses of botulinum toxin in dermatology.

Efficacy and safety of botulinum toxin injection in reducing deltoid muscle hypertrophy

With the increasing demand for body contouring, botulinum toxin (BTX) injection is being widely used off-label for muscular hypertrophy. However, to the best of our knowledge, no study has investigated the clinical efficacy of BTX type A (BTX-A) in deltoid muscle hypertrophy. This study was conducted to evaluate the efficacy and safety of intramuscular injection of BTX in reducing deltoid muscle hypertrophy. Overall, 10 patients with bilateral deltoid muscle hypertrophy were treated with an intramuscular injection of prabotulinum toxin A, with a total of 50 units [U] administered per patient. As measured by ultrasonography, the thickness of the deltoid muscles was significantly decreased at weeks 2 and 12. In addition, the clinical assessment score by blinded investigators was improved after the treatment; however, patients' satisfaction scores were relatively low. No major complications were reported. Therefore, intramuscular injection of BTX-A seems to be a candidate for novel treatment option for deltoid muscle hypertrophy. Further larger clinical studies are warranted to confirm the efficacy of BTX-A.

Botulinum Toxin Injections for Leg Contouring in East Asians

BACKGROUND

A common aesthetic concern among East Asian women is enlarged calves. Although surgical resection has been a traditional treatment option, botulinum toxin injections into the gastrocnemius muscle are an emerging, noninvasive alternative.

OBJECTIVE

To perform a literature review on botulinum toxin injections for leg contouring.

MATERIALS AND METHODS

A literature review was conducted using PubMed, Web of Science, Embase, and Cochrane's CENTRAL database to identify articles relating to combinations of the terms botulinum toxin, gastrocnemius, calves, and leg contouring.

RESULTS

Based on the limited publications to date, the authors prepared a review on how to treat an enlarged calf with botulinum toxin including injection techniques, anticipated efficacy, outcome monitoring, and potential side effects.

CONCLUSION

Botulinum toxin injections for calf reduction are an emerging, noninvasive treatment option. Studies to date suggest that it is an efficacious method with few immediate side effects. Future areas for investigation include defining the criteria for calf hypertrophy, minimum effective dosage of botulinum toxin, and the potential long-term effects of injections.

Alternative Clinical Indications of Botulinum Toxin

Botulinum toxin type A (BoNTA) is a powerful neurotoxin that inhibits acetylcholine release from presynaptic vesicles. The potency and safety profile of BoNTA grant the toxin vast therapeutic potential. It has been used off-label for a variety of dermatologic conditions. This review aims to analyze published literature regarding the benefits and risks of the off-label use of BoNTA beyond facial lines, including eccrine hidrocystomas, enlarged pores, keloids and hypertrophic scars, hidradenitis suppurativa, hyperhidrosis, masseter muscle hypertrophy, and salivary gland hypertrophy, among others. A MEDLINE search from January 2000 to December 2019 was conducted on the off-label uses of botulinum toxin in dermatology.

Calf Reduction by Partial Resection of Gastrocnemius Using a Suction-Assisted Cartilage Shaver

BACKGROUND

Long-term aesthetic reduction of the legs in Asians is gaining increasing popularity among cosmetic patients. Current treatment options include botulinum toxin injection, radiofrequency, neurectomy, and total, subtotal, or partial muscle resection of the gastrocnemius. Partial resection using Kelly forceps was introduced in 2000. This article presents the use of a suction-assisted cartilage shaver to perform partial resection, describing the procedures and shaver modifications and evaluating its use.

METHODS

A retrospective review of 71 cases with a minimum 6-month follow-up (average, 36.5 months; range, 6 to 160 months) was performed. Twenty partial calf reductions were performed with a short shaver, 27 with a long shaver, and 24 with an endoscope-guided long shaver.

RESULTS

Mean reduction of calf circumference was 2 cm (range, -1 to 6 cm); the mean preoperative and postoperative calf circumferences were 35.8 cm and 33.8 cm, respectively. Mean tissue reduction per calf was 110 g (range, 25 to 300 g).Two patients developed larger calves after surgery, one because of weight gain and the other because of weight training. Complications included surface irregularity (n = 4, 5.6 percent), numbness over the lateral ankle or lateral foot (n = 9, 12.7 percent), hematoma clot requiring surgical evacuation (n = 11, 15.5 percent), prolonged seroma (n = 2, 2.8 percent), and left ankle plantar-flexion contracture due to tight, sustained postsurgery bandaging (n = 1, 1.5 percent). Scar-related complications were hyperpigmentation (n = 6, 8.5 percent), depressed scars (n = 5, 7 percent), and hypertrophic scars (n = 2, 2.8 percent).

CONCLUSIONS

Short, long, and endoscope-guided long suction-assisted cartilage shavers for partial resection of calf muscles can be used effectively to reduce the calf. Several mostly treatable complications were noted.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

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

BACKGROUND

Treatments including selective neurectomy, muscle resections and botulinum toxin A (BTX) injections have been used to improve the stocky appearance of calves. BTX injection has the advantages of high efficiency and is almost noninvasive. However, criterion standards of injection are still missing.

OBJECTIVE

We aimed to establish a method to classify the hypertrophic calf for a personalized treatment and set up an injection protocol based on the findings.

METHODS

Three-dimensional CT reconstruction was used to measure the thickness and cross-sectional area of the triceps surae. B-mode ultrasound and palpation were used to evaluate the muscle thickness and determine the dosage. Patients were followed 3 and 6 months after the treatment.

RESULTS

A total of 112 legs were classified into three degrees of thickness (< 15 mm, 15-25 mm and > 25 mm). Twenty-seven subjects were treated with an individualized BTX (100-300 U). Maximal circumference decreased 0.33 ± 0.00 cm after 3 month (p < 0.05) and 0.67 ± 0.11 cm after 6 months (p < 0.01). The angulated calf contour was improved. No severe side effects were reported.

CONCLUSIONS

Localizing and dosage are the key points when applying BTX. Dosage should be decided by muscle thickness instead of circumference. BTX treatment improves the prominent contour of the calf rather than reducing the volume.

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.