- Email: [email protected]
CONGENITAL UNILATERAL UPPER LIMB MUSCULAR HYPERTROPHY ASSOCIATED WITH CONTRACTURE OF AN EXTRINSIC EXTENSOR TENDON
ARTICLE IN PRESS CONGENITAL UNILATERAL UPPER LIMB MUSCULAR HYPERTROPHY ASSOCIATED WITH CONTRACTURE OF AN EXTRINSIC EXTENSOR TENDON S. IMAI, E. ISOYA, M. KUBO, N. KODAMA and Y. MATSUSUE From the Physical Medicine and Rehabilitation, Department of Orthopaedic Surgery, Shiga University of Medical Science, Shiga-ken, Japan
We report a case of congenital unilateral upper limb muscular hypertrophy which presented with loss of extensor tendon excursion of a single digit in late adolescence. The reason for the problem arising is not clear and is not clearly explained by the underlying congenital pathology. Journal of Hand Surgery (European Volume, 2007) 32E: 3: 308–310 Keywords: overgrowth, muscle hypertrophy, aberrant muscle, extensor contracture, joint deformity, congenital malformation
Congenital unilateral upper limb muscular hypertrophy was first reported as duplication of the thenar and hypothenar muscles in an incestuous offspring (Mizuoka et al., 1962). Its major clinical feature is an idiopathic overgrowth problem of skeletal muscles, without primary skeletal abnormalities, of an entire upper limb, often more prominent in the hand. The excessive muscle volume of the hand is attributed to hypertrophied and/ or aberrant intrinsic muscles. The affected muscles are not only hypertrophied but also functionally deficient. The condition is often associated with ulnar drift of the fingers, excessive spreading at the metacarpophalangeal (MCP) joints and a variety of contractures of the joints (Takka et al., 2005). Our review of the literature identifies 15 cases of congenital unilateral upper limb muscular hypertrophy since the initial report (Abe et al., 1975; Yakumaru et al., 1980; Seto et al., 1992; So, 1992; Lanz et al., 1994; Tanabe et al., 1997; Teoh et al., 2001; Takka et al., 2005). We report a case of this condition which presented with a loss of extensor tendon excursion of a single digit in late adolescence.
the middle finger except in the fully extended wrist position, suggesting limitation of normal excursion of the extrinsic extensor tendon. The right upper extremity was also obviously hypertrophied relative to the left side and was 3:5 cm longer (Fig 1a). Although the skeleton of the right upper limb was larger than that of the left side, there were no bony deformities (Fig 2a). Excessive muscle volume could be seen in the thenar and hypothenar eminences (arrows, Fig 2b) and MRI showed generalised hypertrophy of the intrinsic muscles (Fig 2b). This hypertrophy had been present since birth and the pediatricians and medical geneticists had been unable to relate it to known syndromes. At surgery, the extensor digitorum communis muscle was found to give rise to two tendons to the middle finger. Intramuscular exploration identified an absence of a normal musculotendinous junction for these tendons, but found that they were connected to the surrounding fascia by dense connective tissue. There was no sign of previous injury or inflammation. A 3 cm lengthening was achieved by creating a single tendon, by dividing one tendon proximally and the other distally and weaving the tendon ends together. Lengthening by 3 cm was found to result in the best tenodesis effect. The patient recovered firm grip in a more functional wrist position. He could keep the fingers extended with the wrist in the neutral position, but he could not fully extend the middle finger with his wrist in 30 of extension.
CASE PRESENTATION A 25 year-old, primary school teacher presented with difficulty flexing his middle finger. While he could flex the middle finger with his wrist fully extended, it was hyperextended when his wrist was in the neutral position (Fig 1a). He claimed that the difficulty appeared so gradually that he could not recall when it started. However, he was certain that he could flex the middle finger when practicing karate in high school. Slight ulnar deviation of the fingers when flexing the MCP joints and a slight pronation deformity of the index finger were the only deformities noted before the difficulty flexing the middle finger appeared (Fig 1b). Physical examination showed a limitation of flexion of
DISCUSSION Congenital unilateral upper limb muscular hypertrophy (CUULMH) is primarily characterised by excessive muscle volume of an entire upper limb, often more prominent in the hand. The excessive muscle volume of the hand is attributed to hypertrophied and/or aberrant intrinsic muscles. CUULMH is distinct from the 308
ARTICLE IN PRESS CONGENITAL UNILATERAL UPPER LIMB MUSCULAR HYPERTROPHY
309
Fig 1 Pre-operative appearance of the right upper limb: (a) the right upper limb was generally hypertrophied and 3:5 cm longer than the left and (b) during his high school time, the patient could flex the middle finger to hold a bottle with his wrist in the neutral position. Slight ulnar deviation of the fingers when flexing the MCP joints as well as slight pronation deformity of the index finger were noted before the extension contracture of the middle finger developed.
secondary overgrowth problems which occurs as a part of recognised systemic syndromes, such as Proteus syndrome. The absence of involvement of other organ systems may lead to an erroneous assumption that CUULMH is a category of idiopathic hemihypertrophy. However, CUULMH may be distinguished from idiopathic hemihypertrophy by the presence of hand deformities, which do not appear with idiopathic hemihypertrophy. Lanz et al. (1994) reported three cases of CUULMH and suggested that the hypertrophy of the normal muscles and an assortment of accessory muscles accounted for the unilateral upper limb hyperplasia. In these cases, the accessory muscles inserted aberrantly onto the ulnar base of the proximal phalanx and appeared to promote the ulnar deviation of the fingers. In addition to hypertrophic intrinsic muscles, the patient reported by So (1992) had an anomalous epiphysis at the base of second metacarpal bone, contributing to the pronounced ulnar drift deformity. These and other authors agree that the joint deformities progress with growth (Lanz et al., 1994; So, 1992; Tanabe et al., 1997). Takka et al. (2005) noted no radiographic bony deformity in a neonatal case, but spreading of the metacarpal bones, presumably as a result of the increasing size of the hypertrophied intrinsic muscles, after 3 years of follow-up. In this case, a hypertrophied extensor indicis proprius with reduced excursion of its tendon caused a difficulty of flexion of the index finger in a manner similar to our case. The difficulty flexing the middle finger in our case developed after reaching
Fig 2 Pre-operative hand X-ray and MRI: (a) an anteroposterior X-ray of both hands showing the proportionally enlarged skeletal components of the right hand, but without bony deformities. Excessive muscle volume is noted in the right thenar and hypothenar eminences (arrows) and (b) MRI showing generalised hypertrophy of the intrinsic interosseous muscles.
skeletal maturity, suggesting that joint deformities of other digits may continue to progress. It has been recognised previously that surgery on the joint deformities does not always result in satisfactory corrections and the joint deformities appear to continue to progress after surgery (Lanz et al., 1994; Tanabe et al., 1997). The wide variety and complexity of the attendant joint deformities does not fit easily with a simple explanation of deformities caused by muscle bulk, or imbalance of muscles, as a result of hypertrophy of one muscle group.
References Abe I, Iwao T, Ninomiya S et al. (1975). Particular anomaly of the hand: a case report of four cases. Seikeigeka, 26: 1285–1287. Lanz U, Hahn P, Varela C (1994). Congenital unilateral muscle hyperplasia of the hand with ulnar deviation of the fingers. Journal of Hand Surgery, 19B: 683–688.
ARTICLE IN PRESS 310
Mizuoka J, Horio S, Ohmiya K (1962). Duplication of thenar and hypothenar muscles in an incestuous offspring: a case report. Seikeigeka, 13: 963–965. Seto Y, Nishijima N, Mototsu M et al. (1992). Congenital anomaly of the hand due to aberrant muscles. Central Japan Journal of Orthopaedic Surgery and Traumatology, 34: 985–987. So YC (1992). An unusual association of the windblown hand with upper limb hypertrophy. Journal of Hand Surgery, 17B: 113–117. Takka S, Doi K, Hattori Y et al. (2005). Proposal of new category for congenital unilateral upper limb muscular hypertrophy. Annals of Plastic Surgery, 54: 97–102. Tanabe K, Tada K, Doi T (1997). Unilateral hypertrophy of the upper extremity due to aberrant muscles. Journal of Hand Surgery, 22B: 253–257. Teoh LC, Yong FC, Guo CM (2001). Congenital isolated upper limb hypertrophy with hand abnormality: a report of two cases. Journal of Hand Surgery, 26: 492–495.
THE JOURNAL OF HAND SURGERY VOL. 32E No. 3 JUNE
2007
Yakumaru H, Watanabe M, Koike M et al. (1980). Macrocheina due to aberrant muscle and muscular hypentophy. Seikeigeka, 31: 1646–1648. Received: 18 November 2006 Accepted after revision: 4 December 2006 Dr Shinji Imai, MD, PhD, Physical Medicine and Rehabilitation, Departmentof Orthopaedic Surgery, Shiga University of Medical Science,Setatsukinowa-cho, Otsu-shi, Shiga-ken 520-2192, Japan. Tel.: +81 77 548 2252; fax: +81 77 548 2254. E-mail: [email protected]
r 2007 The British Society for Surgery of the Hand. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhsb.2006.12.007 available online at http://www.sciencedirect.com
We report a case of congenital unilateral upper limb muscular hypertrophy which presented with loss of extensor tendon excursion of a single digit in late adolescence. The reason for the problem arising is not clear and is not clearly explained by the underlying congenital pathology. Journal of Hand Surgery (European Volume, 2007) 32E: 3: 308–310 Keywords: overgrowth, muscle hypertrophy, aberrant muscle, extensor contracture, joint deformity, congenital malformation
Congenital unilateral upper limb muscular hypertrophy was first reported as duplication of the thenar and hypothenar muscles in an incestuous offspring (Mizuoka et al., 1962). Its major clinical feature is an idiopathic overgrowth problem of skeletal muscles, without primary skeletal abnormalities, of an entire upper limb, often more prominent in the hand. The excessive muscle volume of the hand is attributed to hypertrophied and/ or aberrant intrinsic muscles. The affected muscles are not only hypertrophied but also functionally deficient. The condition is often associated with ulnar drift of the fingers, excessive spreading at the metacarpophalangeal (MCP) joints and a variety of contractures of the joints (Takka et al., 2005). Our review of the literature identifies 15 cases of congenital unilateral upper limb muscular hypertrophy since the initial report (Abe et al., 1975; Yakumaru et al., 1980; Seto et al., 1992; So, 1992; Lanz et al., 1994; Tanabe et al., 1997; Teoh et al., 2001; Takka et al., 2005). We report a case of this condition which presented with a loss of extensor tendon excursion of a single digit in late adolescence.
the middle finger except in the fully extended wrist position, suggesting limitation of normal excursion of the extrinsic extensor tendon. The right upper extremity was also obviously hypertrophied relative to the left side and was 3:5 cm longer (Fig 1a). Although the skeleton of the right upper limb was larger than that of the left side, there were no bony deformities (Fig 2a). Excessive muscle volume could be seen in the thenar and hypothenar eminences (arrows, Fig 2b) and MRI showed generalised hypertrophy of the intrinsic muscles (Fig 2b). This hypertrophy had been present since birth and the pediatricians and medical geneticists had been unable to relate it to known syndromes. At surgery, the extensor digitorum communis muscle was found to give rise to two tendons to the middle finger. Intramuscular exploration identified an absence of a normal musculotendinous junction for these tendons, but found that they were connected to the surrounding fascia by dense connective tissue. There was no sign of previous injury or inflammation. A 3 cm lengthening was achieved by creating a single tendon, by dividing one tendon proximally and the other distally and weaving the tendon ends together. Lengthening by 3 cm was found to result in the best tenodesis effect. The patient recovered firm grip in a more functional wrist position. He could keep the fingers extended with the wrist in the neutral position, but he could not fully extend the middle finger with his wrist in 30 of extension.
CASE PRESENTATION A 25 year-old, primary school teacher presented with difficulty flexing his middle finger. While he could flex the middle finger with his wrist fully extended, it was hyperextended when his wrist was in the neutral position (Fig 1a). He claimed that the difficulty appeared so gradually that he could not recall when it started. However, he was certain that he could flex the middle finger when practicing karate in high school. Slight ulnar deviation of the fingers when flexing the MCP joints and a slight pronation deformity of the index finger were the only deformities noted before the difficulty flexing the middle finger appeared (Fig 1b). Physical examination showed a limitation of flexion of
DISCUSSION Congenital unilateral upper limb muscular hypertrophy (CUULMH) is primarily characterised by excessive muscle volume of an entire upper limb, often more prominent in the hand. The excessive muscle volume of the hand is attributed to hypertrophied and/or aberrant intrinsic muscles. CUULMH is distinct from the 308
ARTICLE IN PRESS CONGENITAL UNILATERAL UPPER LIMB MUSCULAR HYPERTROPHY
309
Fig 1 Pre-operative appearance of the right upper limb: (a) the right upper limb was generally hypertrophied and 3:5 cm longer than the left and (b) during his high school time, the patient could flex the middle finger to hold a bottle with his wrist in the neutral position. Slight ulnar deviation of the fingers when flexing the MCP joints as well as slight pronation deformity of the index finger were noted before the extension contracture of the middle finger developed.
secondary overgrowth problems which occurs as a part of recognised systemic syndromes, such as Proteus syndrome. The absence of involvement of other organ systems may lead to an erroneous assumption that CUULMH is a category of idiopathic hemihypertrophy. However, CUULMH may be distinguished from idiopathic hemihypertrophy by the presence of hand deformities, which do not appear with idiopathic hemihypertrophy. Lanz et al. (1994) reported three cases of CUULMH and suggested that the hypertrophy of the normal muscles and an assortment of accessory muscles accounted for the unilateral upper limb hyperplasia. In these cases, the accessory muscles inserted aberrantly onto the ulnar base of the proximal phalanx and appeared to promote the ulnar deviation of the fingers. In addition to hypertrophic intrinsic muscles, the patient reported by So (1992) had an anomalous epiphysis at the base of second metacarpal bone, contributing to the pronounced ulnar drift deformity. These and other authors agree that the joint deformities progress with growth (Lanz et al., 1994; So, 1992; Tanabe et al., 1997). Takka et al. (2005) noted no radiographic bony deformity in a neonatal case, but spreading of the metacarpal bones, presumably as a result of the increasing size of the hypertrophied intrinsic muscles, after 3 years of follow-up. In this case, a hypertrophied extensor indicis proprius with reduced excursion of its tendon caused a difficulty of flexion of the index finger in a manner similar to our case. The difficulty flexing the middle finger in our case developed after reaching
Fig 2 Pre-operative hand X-ray and MRI: (a) an anteroposterior X-ray of both hands showing the proportionally enlarged skeletal components of the right hand, but without bony deformities. Excessive muscle volume is noted in the right thenar and hypothenar eminences (arrows) and (b) MRI showing generalised hypertrophy of the intrinsic interosseous muscles.
skeletal maturity, suggesting that joint deformities of other digits may continue to progress. It has been recognised previously that surgery on the joint deformities does not always result in satisfactory corrections and the joint deformities appear to continue to progress after surgery (Lanz et al., 1994; Tanabe et al., 1997). The wide variety and complexity of the attendant joint deformities does not fit easily with a simple explanation of deformities caused by muscle bulk, or imbalance of muscles, as a result of hypertrophy of one muscle group.
References Abe I, Iwao T, Ninomiya S et al. (1975). Particular anomaly of the hand: a case report of four cases. Seikeigeka, 26: 1285–1287. Lanz U, Hahn P, Varela C (1994). Congenital unilateral muscle hyperplasia of the hand with ulnar deviation of the fingers. Journal of Hand Surgery, 19B: 683–688.
ARTICLE IN PRESS 310
Mizuoka J, Horio S, Ohmiya K (1962). Duplication of thenar and hypothenar muscles in an incestuous offspring: a case report. Seikeigeka, 13: 963–965. Seto Y, Nishijima N, Mototsu M et al. (1992). Congenital anomaly of the hand due to aberrant muscles. Central Japan Journal of Orthopaedic Surgery and Traumatology, 34: 985–987. So YC (1992). An unusual association of the windblown hand with upper limb hypertrophy. Journal of Hand Surgery, 17B: 113–117. Takka S, Doi K, Hattori Y et al. (2005). Proposal of new category for congenital unilateral upper limb muscular hypertrophy. Annals of Plastic Surgery, 54: 97–102. Tanabe K, Tada K, Doi T (1997). Unilateral hypertrophy of the upper extremity due to aberrant muscles. Journal of Hand Surgery, 22B: 253–257. Teoh LC, Yong FC, Guo CM (2001). Congenital isolated upper limb hypertrophy with hand abnormality: a report of two cases. Journal of Hand Surgery, 26: 492–495.
THE JOURNAL OF HAND SURGERY VOL. 32E No. 3 JUNE
2007
Yakumaru H, Watanabe M, Koike M et al. (1980). Macrocheina due to aberrant muscle and muscular hypentophy. Seikeigeka, 31: 1646–1648. Received: 18 November 2006 Accepted after revision: 4 December 2006 Dr Shinji Imai, MD, PhD, Physical Medicine and Rehabilitation, Departmentof Orthopaedic Surgery, Shiga University of Medical Science,Setatsukinowa-cho, Otsu-shi, Shiga-ken 520-2192, Japan. Tel.: +81 77 548 2252; fax: +81 77 548 2254. E-mail: [email protected]
r 2007 The British Society for Surgery of the Hand. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhsb.2006.12.007 available online at http://www.sciencedirect.com