Botox, Calf

ORIGINAL ARTICLE

Botulinum Toxin A for Aesthetic Contouring of Enlarged Medial Gastrocnemius Muscle H YUN -J EONG L EE , MD, D ONG -W ON L EE , MD, Y EON -H O PARK , MD, M I -K YUNG C HA , MD, H ONG -S IK K IM , MD, AND S EOG -J UN H A , MD

BACKGROUND. Oversized, muscular calves can cause psychological stress in women. Botulinum toxin A has been used in the treatment of benign masseteric hypertrophy with correction of the squared facial appearance. It is believed that botulinum toxin might also be effective in reducing enlarged calf muscles. OBJECTIVE. This study was performed to investigate the effect of botulinum toxin A in reducing enlarged medial gastrocnemius muscles in volunteers with muscular legs. METHODS. Botulinum toxin A of 32, 48, or 72 U was injected in each medial head of the gastrocnemius muscle in six women. Clinical photography was taken and the leg circumferences were measured. The functional evaluations were performed by examining range of joint motion and motor and sensory examination.

RESULTS. All of the enrolled subjects showed a reduction in the medial gastrocnemius muscle after the botulinum toxin injection. The reduction in medial calf was noticed even after 1 week and the effect of was well maintained for 6 months. Leg contouring was obtained by the botulinum toxin treatment. The middle leg circumference showed a slight decrease in five subjects. No functional disabilities were observed. CONCLUSION. Botulinum toxin A can be used to contour the aesthetic enlargement of the medial gastrocnemius muscle with slight reduction in volume. Botulinum toxin-induced atrophy of the muscle caused no functional disabilities and the clinical improvement was well maintained for 6 months after the botulinum toxin A injection.

HYUN-JEONG LEE, MD, DONG-WON LEE, MD, YEON-HO PARK, MD, MI-KYUNG CHA, MD, HONG-SIK KIM, MD, AND SEOG-JUN HA, MD HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.

IN ORIENTAL women, shapeless legs with thick calf muscles are a common aesthetic problem. Muscle hypertrophy of the lower extremities is rarely reported in conditions with peripheral nerve lesions,1 chronic spinal atrophy,2 chronic recurrent polyneuropathy,3 and poliomyelitis,4 but in most cases, the causes of aesthetic hypertrophy of the gastrocnemius muscle are unknown. Invasive, surgical treatments have been performed for the aesthetic reduction of hypertrophic calf muscles. Liposuction has not been recommended as a suitable method for the muscular legs, because the gastrocnemius muscle rather than subcutaneous fat is a major factor determining the shape and size of muscular legs.5 Surgical resection of partial gastrocnemius muscle has been successfully performed to reduce hypertrophic calves. No functional instability in walking or running has been reported in a long-term follow-up.5–8 Recently, botulinum toxin A was used to treat benign masseteric hypertrophy with the relief of pain and the correction of a squared facial appearance.9–11

Address correspondence and reprint requests to: Hyun-Jeong Lee, MD, Jeonghyun B/D 8th floor, 250-3, Seohyun-dong, Bundang-ku, Seongnamcity, Kyunngido, 463-050 Korea, or e-mail: [email protected].

The therapeutic effect was resulted from the botulinum toxin A-induced inactivity atrophy of the masseter muscle. It is possible that botulinum toxin A can be effective in reducing enlarged calf muscles. Therefore, this study examined the effect of botulinum toxin A injections in volunteers with muscular legs. In this preliminary study, botulinum toxin A was injected in the medial head of the gastrocnemius muscle, which is the most prominent muscle of the calf and is functionally redundant.

Materials and Methods Botulinum toxin A was injected in six female volunteers (age range 24–30 years, mean age 28.7  4.84 years) with moderate aesthetic hypertrophy of the medial gastrocnemius muscle after obtaining written informed consent. The subjects had no diseases or occupations known to be associated with the calf muscle hypertrophy. Each vial of botulinum toxin A contained 100 U of Clostridium botulinum toxin type A with human serum albumin and sodium chloride in a sterile, vacuum-dried form without preservatives (Botox, purified neurotoxin complex, Allergan, Inc., Irvine, CA). All the injections were prepared by reconstituting a 100-U vial of botulinum

r 2004 by the American Society for Dermatologic Surgery, Inc.  Published by Blackwell Publishing, Inc. ISSN: 1076-0512/04/$15.00/0  Dermatol Surg 2004;30:867–871

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toxin A with 2.5 mL of sterile preservative-free saline to achieve a concentration of 4 U/0.1 mL in the botulinum toxin A vials. The subjects received doses of 32 U (Subjects 1 and 2), 48 U (Subjects 3 and 4), or 72 U (Subjects 5 and 6) in each side of the leg at the initial visit. The botulinum toxin A dose was selected according to the gross size of the contracted medial gastrocnemius muscle in the tiptoe position. The gross size of the contracted gastrocnemius muscle did not correlate with the leg circumference. The injections were performed under sterile conditions using 1-in.-long, 23-gauge needles. Three to six intramuscular injections with 1.5- to 2-cm intervals were performed along the most prominent part of the medial gastrocnemius muscle in each leg in the prone position. Subjects were evaluated at the baseline and 1 and 6 months after the injection. Clinical photography was taken in the standing position on a flat floor (relaxed muscle) and on the tiptoe (contracted muscle). The leg circumferences were measured at the superior, middle, and inferior levels6 in the tiptoe position. Length of the leg was measured from the lateral malleolar protuberance to the lateral end of the popliteal skin crease. The total length was divided to four equal parts, and the leg circumference was measured at three levels. The leg circumference measurements were made by the same investigator (H.J.L.) at each visit. Functional evaluations were performed by examining range of joint motion and motor and sensory examination.

Results All of the enrolled subjects showed clinical improvement with a reduction in the medial gastrocnemius muscle after the botulinum toxin A injection (Figures 1–4). The reduction in the medial calf was noticed even after 1 week, and the improvement was clearly seen at 1 month. A volume reduction in the medial calf was apparent in the tiptoe position with the contracted muscle (Figures 1–3), but this was also observed in the normal standing position on a flat floor (Figure 4). The effect of the botulinum toxin A injection was well maintained for 6 months after the injection. In Subject 5, clinical picture could be taken at 12 months after the treatment (Figure 5). The medial gastrocnemius muscle became enlarged, but the clinical improvement was still maintained in comparison with the baseline picture. Besides the reduction in the medial gastrocnemius muscle, leg contouring was also obtained as a result of the botulinum toxin A treatment. The clinical pictures revealed that the most prominent point in the contour of the medial calf moved upward to approximately the three-fourths level of the calf (Figures 2 and 3).

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Figure 1. Clinical pictures of the posterior calf in Subject 1 on the tiptoe position before the injection of 32 U of botulinum toxin A in each medial gastrocnemius muscle (A) and 1 (B) and 6 (C) months after the treatment. The size of the medial gastrocnemius muscle was decreased in volume with a change in the contour of the medial calf.

Figure 2. Clinical pictures of the posterior calf in Subject 4 on the tiptoe position before the injection of 48 U of botulinum toxin A in each medial gastrocnemius muscle (A) and 1 (B) and 6 (C) months after the treatment. Angulated masculine bulging of the medial gastrocnemius muscle had disappeared after the botulinum toxin A treatment with an upward movement of the most prominent point (indicated by the pointer) of the leg contour.

The change in the leg circumference was most remarkable in the middle leg circumference, which reflects the volume reduction of the medial gastrocnemius muscle (Table 1, Figure 6). The middle leg circumference was decreased in all subjects except for Subject 4. These five subjects also showed a slight decrease in the superior or low leg circumferences. In Subjects 2, 5, and 6, the decrease in the middle leg circumference was most prominent, which consistently decreased during the follow-up visits. In Subject 4, despite the clinical improvement, there was a slight increase in the posttreatment leg circumferences compared to the pretreatment value. Subjective degree of improvement was mild in Subjects 3 and 5 and moderate in the other four

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Figure 3. Clinical pictures of the posterior calf in Subject 5 on the tiptoe position before the injection of 72 U of botulinum toxin A in each medial gastrocnemius muscle (A) and 1 (B) and 6 (C) months after treatment. The angulated masculine bulging of the medial gastrocnemius muscle had disappeared after the botulinum toxin A treatment with an upward movement of the most prominent point (indicated by the pointer) of the leg contour.

Figure 4. Clinical pictures of the posterior calf in Subject 5 in the normal standing position on a flat floor before the injection of 72 U of botulinum toxin A in each medial gastrocnemius muscle (A) and 1 (B) and 6 (C) months after the treatment. The bulging contour of the medial gastrocnemius muscle had disappeared after the botulinum toxin A treatment with the atrophy of medial gastrocnemius muscle after the botulinum toxin A treatment.

subjects. The subjects felt some softening of the medial part of their calf after the injections. The subjects complained of mild tenderness lasting a few days owing to the intramuscular injections. Bruising was noticed at the injection sites in a few subjects. Functional evaluations were normal in all subjects with no discomfort in the gait and running.

Discussion Botulinum toxin A has been widely used in the management of a variety of disorders involving muscle overactivity.12–15 Botulinum toxin A has been successfully used to treat masseteric hypertrophy, which corrected the squared facial appearance along with

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Figure 5. Clinical pictures in Subject 5 at 12 months after the treatment on the tiptoe position (A) and in the normal standing position (B). The size of medial gastrocnemius became enlarged, but the improvement in the angulated bulging contour is still maintained along with the slight decrease in the volume of the muscle.

the elimination of the associated pain in this condition.9–11 Botulinum toxin A caused marked inactivity atrophy and the atrophy was maintained for more than 1 year in most cases.9–11 In this study, botulinum toxin A was used to treat a hypertrophic medial head of the gatrocnemius muscle. The contour of the posterior side of the legs is determined by the gastrocnemius and soleus muscles. The surface contours of the legs are more closely related to the superficially located gastrocnemius muscle.5 Commonly, the medial head of the gastrocnemius muscle forms a prominent contour medially in the posterior aspects of the legs in Korean women. The purpose of this preliminary study was to investigate the effect of a botulinum toxin A injection in contouring the medial parts of the legs and to assess the duration of the clinical effects as well as proper dosage of botulinum toxin A in Korean women with enlarged gastrocnemius muscles. A partial excision of the gastrocnemius muscle has been successfully performed with few functional disabilities.5–8 Selective neurectomy of the nerve to the medial head of the gastrocnemius muscle can also reduce the volume of the muscle.5 These methods are invasive, surgical treatments for a calf reduction. The greatest advantage of botulinum toxin A treatment is that the aesthetic problem of thick, muscular legs can be solved using a simple, noninvasive technique. In this study, botulinum toxin A was effective in contouring the medial side of the legs with a slight volume reduction. The thick, angulated bulging contour of the medial gastrocnemius was smoothened with the upward location of the most prominent part of the leg. The criteria for an aesthetically pleasing leg includes maximum circumference being three-fourths of the leg length, which is often located on or below the superior level of the four equal parts of the leg.16

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Table 1. Data of the Middle Leg Circumference in Six Women after a Botulinum Toxin A Injection into the Medial Gastrocnemius Muscle Middle Leg Circumference (cm) 32 U of Botulinum Toxin A per Each Side

Baseline 1 month 6 months

48 U of Botulinum Toxin A per Each Side

72 U of Botulinum Toxin A per Each Side

Subject 1

Subject 2

Subject 3

Subject 4

Subject 5

Subject 6

34.8 33.2 34.2

34.0 33.3 32.8

33.0 31.5 31.9

30.4 30.5 30.9

34.2 32.4 32.3

33.3 31.8 31.7

Figure 6. Leg circumferences measured before the botulinum toxin A treatment (labeled as visit 1) and 1 (visit 2) and 6 (visit 3) months after the treatment in Subjects 1 (A), 2 (B), 3 (C), 4 (D), 5 (E), and 6 (F).

From this aspect, the botulinum toxin A treatment resulted in a better aesthetic appearance. The botulinum toxin A-induced atrophy of medial gastrocnemius muscle was observed within 1 month

after the injection, and this effect was well maintained for 6 months. In one subject, the botulinum toxin Ainduced clinical improvement still remained at 12 months after the treatment. The hypertrophic masseter muscle treated with botulinum toxin A showed a decrease in the muscle mass over the course of 2 to 8 weeks, and the atrophy was maintained for over 1 year.9–11 This clinical course appears to be similar in the medial gastrocnemius muscle treated with botulinum toxin A. Only the medial head of the gastrocnemius muscle was injected in this study. A reduction of the medial calf could result in an accentuation of the bow appearance of the leg, although this was not the case in our subjects. In an additional trial, both the medial and the lateral gastrocnemius muscle could be injected for the best response. The botulinum toxin A dose used in this study was chosen by considering the amount of botulinum toxin A used in the masseteric hypertrophy, where the masseter muscles were treated with 100 to 300 U of C. botulinum toxin type A-hemagglutinin complex. Three different doses of botulinum toxin A were used according to the gross size of the medial gastrocnemius muscle in this study. Botulinum toxin A doses of 32, 48, or 72 U were all effective in contouring the medial calf. The minimal optimum dosage for reducing the size of the calf muscles needs to be confirmed in a further study. Leg circumference measurements were used in this study to evaluate the volume reduction of the calf. The volume reduction resulting from the botulinum toxin A injection in the medial gastrocnemius muscle was noted clinically, but it resulted in only a small change in the leg circumference measurement. The posttreatment leg circumference was reduced in five of six subjects. The decrease in the leg circumference was most prominent in the middle circumference, which is related to upward movement of the most prominent point of the medial calf. The decrease in the middle leg circumference was in a range of 5 to 20 mm, which reflects only minimal degree of volume reduction. These subtle improvements in leg circumference could

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easily be masked by the leg edema associated with daily physical activity. Subject 3 complained of frequent leg swelling, and pitting edema was observed at the follow-up visit at 2 months. In this context, the leg circumference measurements are not a good measure for assessing the botulinum toxin A treatment for the medial gastrocnemius muscle. In contrast, clinical photography has the greatest importance in the assessment. A limitation in this study is that we did not uniformly define the assessment at the tiptoe position. The volunteers were asked to raise their heels as much as possible on the tiptoe position, but this position was not uniformly defined and was rather subjective. Nevertheless, clinical photography could reflect the clinical improvement despite the slight differences in the level of their heel in the tiptoe position. This different position could also have influenced on the leg circumference measurement. The subjective degree of satisfaction was rather low in the botulinum toxin A calf reduction because it was difficult to perceive the improvements. One cannot observe one’s posterior side of the leg, and the botulinum toxin A-induced volume reduction was not so prominent to be easily recognized. This fact should be clearly communicated to the patients before the botulinum toxin A treatment of the calf, and costeffectiveness should be considered. In conclusion, botulinum toxin A can be used to contour aesthetic hypertrophy of the medial gastrocnemius muscle with a slight volume reduction of the enlarged calf. The botulinum toxin A-induced atrophy of the muscle caused no functional disabilities and the clinical improvement was well maintained for 6 months after the botulinum toxin A injection.

1. Korczyn AD, Kuritzky A, Sandbank U. Muscle hypertrophy with neuropathy. J Neurol Sci 1978;38:399–408. 2. Pearn J, Hudgson P. Anterior-horn cell degeneration and gross calf hypertrophy with adolescent onset: a new spinal muscular atrophy syndrome. Lancet 1978;1:1059–61. 3. Valenstein E, Watson RT, Parker JL. Myokymia, muscle hypertrophy and percussion ‘myotonia’ in chronic recurrent polyneuropathy. Neurology 1978;28:1130–4. 4. Bertorini TE, Igarashi M. Postpoliomyelitis muscle pseudohypertrophy. Muscle Nerve 1985;8:644–9. 5. Kim IG, Hwang SH, Lew JM, Lee HY. Endoscope-assisted calf reduction in Orientals. Plast Reconstr Surg 2000;106:713–20. 6. Tsai CC, Lee SS, Lai CS, Lin SD, Chiou CS. Aesthetic resection of the gastrocnemius muscle in postpoliomyelitis calf hypertrophy: an uncommon case report. Aesthetic Plast Surg 2001;25:111–3. 7. Lemperle G, Exner K. The resection of gastrocnemius muscles in aesthetically disturbing calf hypertrophy. Plast Reconstr Surg 1998; 102:2230–6. 8. Coert JH, Dellon AL. Clinical implications of the surgical anatomy of the sural nerve. Plast Reconstr Surg 1994;94:850–5. 9. To EW, Ahuja AT, Ho WS, et al. A prospective study of the effect of botulinum toxin A on masseteric muscle hypertrophy with ultrasonographic and electromyographic measurement. Br J Plast Surg 2001;54:197–200. 10. von Lindern JJ, Niederhagen B, Appel T, Berge S, Reich RH. Type A botulinum toxin for the treatment of hypertrophy of the masseter and temporal muscles: an alternative treatment. Plast Reconstr Surg 2001;107:327–32. 11. Finn S, Ryan P, Sleeman D. The medical management of masseteric hypertrophy with botulinum toxin. J Ir Dent Assoc 2000;46: 84–6. 12. Jankovic J, Schwartz K, Donovan DT. Botulinum toxin treatment of cranial-cervical dystonia, spasmodic dysphonia, other focal dystonias and hemifacial spasm. J Neurol Neurosurg Psychiatry 1990;53:633–9. 13. Brin MF. Interventional neurology: treatment of neurological conditions with local injection of botulinum toxin. Arch Neurobiol (Madr) 1991;54(Suppl 3):7–23. 14. Osako M, Keltner JL. Botulinum A toxin (oculinum) in ophthalmology. Surv Ophthalmol 1991;36:28–46. 15. Jankovic J, Brin MF. Botulinum toxin: historical perspective and potential new indications. Muscle Nerve Suppl 1997;6:129–45. 16. Tsai CC, Lin SD, Lai CS, Lin TM. Aesthetic analysis of the ideal female legs. Aesth Plast Surg 2000;24:303–5.

Commentary

Commentary

Enlarged calves caused by hypertrophy of the gastrocnemius muscle is prevalent in Asian women. This condition is commonly referred to as ‘‘radish calf’’ in Chinese society. Making women’s lower legs slimmer is one of the most challenging aesthetic surgeries in Oriental patients. Lee and colleagues conducted an interesting study by injection of botulinum toxin A to reduce volume of medial gastrocnemius muscle. Although the clinical result was not completely satisfactory, the authors have shown that injection of botulinum toxin A with a dosage of up to 72 U is safe without major complications. This preliminary study may encourage more researchers in this field. Before this new indication becomes acceptable, more scientific and meticulous studies must be performed including location and technique of injection, dosage adjustment, objective evaluation methods (ultrasound and MRI, etc.) and long-term effects and safety.

Botulinum toxin A injection is probably one of the fastest growing cosmetic procedures in Asia and this article is certainly interesting because it examines its role in improving the calf contour, a common concern among Asian persons. Nevertheless, there are several pitfalls in this study that should be mentioned. The sample size was small and the observer was not blinded. Furthermore, there was no accurate objective assessment such as the use of radiologic imaging to measure the muscle bulk. Radiologic assessment including ultrasound was commonly used in previous studies to assess the effectiveness of botulinum toxin A for the treatment of masseteric hypertrophy. These limitations imply that findings in this study should be considered to be preliminary in nature. Given the issue of cost-effectiveness, further studies are necessary before one can justify such use of botulinum toxin A.

REN-YEU TSAI, MD Taipei, Taiwan

HENRY H. L. CHAN, MD (LOND), FRCP University of Hong Kong

References