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Bilateral anomalous insertion of flexor pollicis longus
BILATERAL
ANOMALOUS
INSERTION LONGUS
J. NAKAMURA
OF FLEXOR
POLLICIS
and E. KURO
From the Department of Plastic and Reconstructive Surgery, Tokyo Koseinenkin Hospital, Japan
A case of bilateral insertion of flexor pollicis longus to the proximal as well as the distal phalanges is reported. Initially, this case was diagnosed as congenital absence of the flexor pollicis longus, but surgery revealed an intact tendon, with the abnormality only present in the site of insertion. A survey of the literature on congenital abnormalities of flexor pollicis longus failed to reveal any reports of similar abnormalities. Journal of Hand Surgery
(British
and European
Volume, 1993) 18B: 312-31.5
CASE REPORT
the palmar or dorsal sides of the IP joint, and there was no active motion (Fig 1). The joint flexed passively to 20”. The metacarpophalangeal joint was normal, with an active and passive range from 0” to 90”, and the carpometacarpal joint was also normal. The thenar eminence was almost normal on both hands; X-rays were normal (Fig 2). Exploration of the left thumb at 2 years of age revealed an almost normal flexor pollicis longus (FPL) tendon at the level of the proximal phalanx (Fig 3) and the tendon was also present at the wrist level. Traction on this tendon produced thumb flexion only at the MP joint, as was the case pre-operatively. Distal insertion of the tendon was found to extend from the middle of the proximal phalanx to the base of the distal phalanx. It was released from bone up to its normal insertion on the distal phalanx, making flexion of the IP joint possible. Active movement was restored to the pre-operative passive range of 20”. An adhesion of the tendon to the otherwise normal tendon sheath was released at the insertion site. 5 months later similar surgery was performed on the right thumb, and the findings were the same. With postoperative exercises it was possible to restore an active range of 35” to the left thumb. Flexion of the right thumb was still limited to 20”, so a further operation was done 3 years after the initial surgery to release the
A 7-month-old male child presented with inability to flex the interphalangeal joints of both thumbs, and syndactyly between the first two toes of the right foot. Both thumbs were long and slender in appearance, with the IP joints remaining in an extended position at all times. No finger crease could be observed on either
Fig 1
Both thumbs remain permanently in an extended position, with no active motion at all. No finger crease can be observed on the palmar or dorsal sides.
Fig 2 312
Intraarticular
space of the IP joint is approximately
normal.
3i3
FPL INSERTION
Fig 3
(a) Peripheral insertion of FPL spreads out like a fan (b) FPL insertion site is extensive, reaching as far as the proximal phalanx (c) Abnormal insertion of the FPL is released (d) Traction on the FPL at the wrist level resulted in flexion of the MP joint only, with no flexion of the IP joint (e) Flexion of the IP joint became possible after releasing anomalous insertion.
tendon at the insertion site. The IP joint was found to be hypoplastic. The range is now from 0” to 35”, for both active and passive motion (Fig 4). A finger crease on the palmar side of the IP joint can be discerned in the evening.
Group 2
Observed in conjunction with hypoplasia of the thumb (eight cases, eight thumbs; Blair and Omer, 198 1; Rayan, 1984; Tupper, 1969). Group 3
DISCUSSION A review of literature detailing congenital abnormalities of FPL showed that, to date, 39 cases involving 46 thumbs have been reported. These abnormalities can be divided into five different groups as follows. Group i Observed in conjunction with absence of the pectoralis major muscle, the extrinsic or intrinsic muscles, and with radial club hand (two cases, three thumbs; Fromont, 1895; Kitayama and Kawakami, 1982).
Observed in conjunction with absence of the median innervated intrinsic muscles (eight cases, 11 thumbs. Strauch and Spinner, 1976). Group 4 Observed in conjunction with absence of flexor pollicis brevis (one case, two thumbs; Tsuchida et al, 1976). Group 5 Simple abnormalities of FPL alone (20 cases, 22 thumbs; Arminio, 1979; DeHaan et al, 1987; Elsahy, 1976; Hagan
314
THE JOURNAL
Table l--Classification
Group 1 a) b) Group 2
Fig 4
5 years post-operative, bilateral active flexion of the IP joints is 35” (a: right thumb, b: left thumb).
and Idler, 1988; Isizaki et al, 1980; Kawai et al, 1976; Konno et al, 1978; Kiister, 1984; Linburg and Comstock, 1979; Miura, 1977; Miur’a, 1981; Murakami and Edashige, 1980; Salama and Weissman, 1975; Uchida et al, 1985; Uetake et al, 1977; Yoshioka and Yokoyama, 1980). Abnormalities of FPL can be further divided into four groups: a) absence (16 thumbs), b) abnormal connection (14 thumbs), c) anomalous insertion (14 thumbs), d) abnormal course (six thumbs). Simple abnormalities of FPL form the largest group, which are also of major interest in investigating our present case. Complete absence of FPL (Arminio, 1979; DeHaan et al, 1987; Fromont, 1895; Kiister, 1984; Miura, 1977; Strauch and Spinner, 1976; Tsuchida et al, 1976; Uchida et al, 1985) is the most common manifestation of this abnormality, followed by abnormal connection (Elsahy, 1976; Isizaki et al, 1980; Kawai et al, 1976; Linburg and Comstock, 1979; Murakami and Edashige, 1980; Rayan, 1984; Salama and Weissman, 1975; Uetake et al, 1977) and anomalous insertion (Blair and Omer, 1981; Hagan and Idler, 1988; Kawai et al, 1976; Kitayama and Kawakami, 1982; Konno et al, 1978; Miura, 198 1; Rayan, 1984; Tupper, 1969; Yoshioka and Yokoyama, 1980). The most frequently observed anomalous insertion was into the transverse
OF HAND
SURGERY
VOL. 18B No. 3 JUNE
1993
of 46 thumbs reported in literature
Absence Anomalous insertion
2 thumbs 1 thumb
b + c) Abnormal connection and anomalous insertion c+ d) Malposition and anomalous insertion
2 thumbs 6 thumbs
Group 3
a) ?
Absence
7 thumbs 4 thumbs
Group 4
a)
Absence
2 thumbs
Group 5
a) b) c)
Absence Abnormal connection Anomalous insertion
5 thumbs 12 thumbs 5 thumbs
carpal ligament, with four thumbs, followed by insertion of a bifurcated accessory tendon into the extensor or dorsal aponeuroses. In the case we describe, the insertion site of the flexor pollicis longus extended onto the proximal phalanx, causing an inability to flex the IP joint. This can be interpreted in two ways. The anomalous insertion can be considered to be a primary disorder, or the extremely limited pre-operative passive movement in the IP joint and the surgical findings can be interpreted to suggest an initial congenital hypoplasia of the joint itself causing a secondary manifestation in the form of anomalous insertion of the tendon. Our case fits into section c) of Group 5 (Table l), but one of the bifurcated tendons exhibited very similar abnormalities to those found in Group 2 (Rayan, 1984). Reports of similar abnormalities were not found among cases in Groups 4 or 5. References ARMINIO, J. A. (1979). Congenital anomaly of the thumb: Absent flexor pollicis longus tendon. Journal of Hand Surgery, 4: 5: 487-488. BLAIR, W. F. and OMER, G. E. (1981). Anomalous insertion of the flexor pollicis longus. Journal of Hand Surgery, 6: 3: 241-244. DeHAAN, M. R., WONG, L. B. and PETERSEN, D. P. (1987). Congenital anomaly of the thumb: Aplasia of the flexor pollicis longus. Journal of Hand Surgery, 12A: 1: 108-109. ELSAHY, N. I. (1976). Abnormal flexor pollicis longus sheath: Case report. Acta Chirurgica Plastica, 18: 1: 40-42. FROMONT (1895). Anomalies musculaires multiples de la main. Absence du flkhisseur propre du pouce. Absence des muscles de l’eminence thenar. Lombricaux supplCmentaires. Bulletins de la Sock% Anatamoque de Paris, 9: 395-401. HAGAN, H. .I. and IDLER, R. S. (1988). Limitation of thumb flexion due to an unusual insertion of the flexor pollicis longus. Journal of Hand Surgery, 13B: 4: 474-476. ISIZAKI, T., OMIYA, K. and SANKI, T. (1980). Congenital 4/5 metacarpal fusion accompanied with anomalous tendon slip from FPL to FDP (II): Report of two cases. Orthopedic Surgery, (Japan) 31: 12: 1649-1652. KAWAI, M., YOSIDA, K. and FUJITA, K. (1976). Congenital malposition of the flexor pollicis longus. Orthopedic Surgery (Japan), 27: 13: 1484-1485. KITAYAMA, Y. and KAWAKAMI, S. (1982). Anomaly of the flexor pollicis longus tendon associated with anomaly of the adductor pollicis muscle: A case report. Clinical Orthopedic Surgery (Japan), 17: 7: 735-739. KONNO, T., KAMESITA, K. and TAKAZAWA, H. (1978). Anomaly of flexor pollicis longus tendon: A case report. Orthopedic Surgery (Japan), 29: 13: 1574-1576. K&TER, G. (1984). Isolated aplasia of the flexor pollicis longus: A case report. Journal of Hand Surgery, 9A: 6: 870-871. LINBURG, R. M. and COMSTOCK, B. E. (1979). Anomalous tendon slips
315
FPL INSERTION from the flexor pollicis lcngus to the flexor digitorum profundus. Journal of Hand Surgery, 4: 1: 79-83. MICRA, T. (1977). Congenital absence of the flexor pollicis longus: A case report. The Hand, 9: 3: 272-274. MIURA, T. (1981). Congenital anomaly of the thumb: Unusual bifurcation of the flexor pollicis longus and its unusual insertion. Journal of Hand Surgery, 6: 6: 613-615. MURAKAMI, Y. and EDASHIGE, K. (1980). Anomalous flexor pollicis longus muscle. The Hand, 12: 1: X2-84. RAYAN, G. M. (1984). Congenital hypoplastic thumb with absent thenar muscles: Anomalous digital neurovascular bundle. Journal of Hand Surgery, 9A: 5: 665-668. SALAMA, R. and WEISSMAN, S. L. (1975). Congenital bilateral anomalous band between flexor and extensor pollicis longus tendon. Report of a case. The Hand, 7: 1: 25-26. STRAUCH, B. and SPINNER, M. (1976). Congenital anomaly of the thumb: Absent intrinsics and flexor pollicis longus. Journal of Bone and Joint Surgery, 58A: 1: 115-118. TSUCHIDA, Y., KASAI, S. and KOJIMA, T. (1976). Congenital absence of
flexor poliicis !ongus and flexor poilicis brevis. A case report. The Hand, 8: 3: 294-297. TUPPER, J. W. (1969). Pollex abductus due to congemtal malposition of the flexor pollicis longus. Journal of Bone and Joint Surgery, 5lA: 7: 1285-1290. UCHIDA, M., KOJIMA, T. and SAKURAI, N. (i985). Congenital absence of flexor pollicis longus without hypoplasia of thenar muscles. Plastic and Reconstructive Surgery; 75: 3: 413-416. UETAKE, M., TSUCHIYA, I., YAMAMOTO, R., KI’4NNO: T. and KAMATA, M. (1977). Anomalous tendon slip from theflexor polhcis longus to the flexor digitorum profundus. Orthopedic surgery (Japan), 28: 13: 1497-1499. YOSHIOKA, Y. and YOKOYAMA; M. (1980). Congemtal absence of the flexor pollicis longus: A case report. Central Japan Journal of Orthopedic Surgery, 23: 6: i660-1662.
Accepted: 30 December 1991 Junji Nakamura, MD, Department of Plastic and Reconstructive Surgery. Tokyo Koseinenkm Hospital 5-1, Tsnkudo-cho Shinjuku-ku, Tokyo i62, Japan. 0 1993 The British Society for Surgery of the Hand
ANOMALOUS
INSERTION LONGUS
J. NAKAMURA
OF FLEXOR
POLLICIS
and E. KURO
From the Department of Plastic and Reconstructive Surgery, Tokyo Koseinenkin Hospital, Japan
A case of bilateral insertion of flexor pollicis longus to the proximal as well as the distal phalanges is reported. Initially, this case was diagnosed as congenital absence of the flexor pollicis longus, but surgery revealed an intact tendon, with the abnormality only present in the site of insertion. A survey of the literature on congenital abnormalities of flexor pollicis longus failed to reveal any reports of similar abnormalities. Journal of Hand Surgery
(British
and European
Volume, 1993) 18B: 312-31.5
CASE REPORT
the palmar or dorsal sides of the IP joint, and there was no active motion (Fig 1). The joint flexed passively to 20”. The metacarpophalangeal joint was normal, with an active and passive range from 0” to 90”, and the carpometacarpal joint was also normal. The thenar eminence was almost normal on both hands; X-rays were normal (Fig 2). Exploration of the left thumb at 2 years of age revealed an almost normal flexor pollicis longus (FPL) tendon at the level of the proximal phalanx (Fig 3) and the tendon was also present at the wrist level. Traction on this tendon produced thumb flexion only at the MP joint, as was the case pre-operatively. Distal insertion of the tendon was found to extend from the middle of the proximal phalanx to the base of the distal phalanx. It was released from bone up to its normal insertion on the distal phalanx, making flexion of the IP joint possible. Active movement was restored to the pre-operative passive range of 20”. An adhesion of the tendon to the otherwise normal tendon sheath was released at the insertion site. 5 months later similar surgery was performed on the right thumb, and the findings were the same. With postoperative exercises it was possible to restore an active range of 35” to the left thumb. Flexion of the right thumb was still limited to 20”, so a further operation was done 3 years after the initial surgery to release the
A 7-month-old male child presented with inability to flex the interphalangeal joints of both thumbs, and syndactyly between the first two toes of the right foot. Both thumbs were long and slender in appearance, with the IP joints remaining in an extended position at all times. No finger crease could be observed on either
Fig 1
Both thumbs remain permanently in an extended position, with no active motion at all. No finger crease can be observed on the palmar or dorsal sides.
Fig 2 312
Intraarticular
space of the IP joint is approximately
normal.
3i3
FPL INSERTION
Fig 3
(a) Peripheral insertion of FPL spreads out like a fan (b) FPL insertion site is extensive, reaching as far as the proximal phalanx (c) Abnormal insertion of the FPL is released (d) Traction on the FPL at the wrist level resulted in flexion of the MP joint only, with no flexion of the IP joint (e) Flexion of the IP joint became possible after releasing anomalous insertion.
tendon at the insertion site. The IP joint was found to be hypoplastic. The range is now from 0” to 35”, for both active and passive motion (Fig 4). A finger crease on the palmar side of the IP joint can be discerned in the evening.
Group 2
Observed in conjunction with hypoplasia of the thumb (eight cases, eight thumbs; Blair and Omer, 198 1; Rayan, 1984; Tupper, 1969). Group 3
DISCUSSION A review of literature detailing congenital abnormalities of FPL showed that, to date, 39 cases involving 46 thumbs have been reported. These abnormalities can be divided into five different groups as follows. Group i Observed in conjunction with absence of the pectoralis major muscle, the extrinsic or intrinsic muscles, and with radial club hand (two cases, three thumbs; Fromont, 1895; Kitayama and Kawakami, 1982).
Observed in conjunction with absence of the median innervated intrinsic muscles (eight cases, 11 thumbs. Strauch and Spinner, 1976). Group 4 Observed in conjunction with absence of flexor pollicis brevis (one case, two thumbs; Tsuchida et al, 1976). Group 5 Simple abnormalities of FPL alone (20 cases, 22 thumbs; Arminio, 1979; DeHaan et al, 1987; Elsahy, 1976; Hagan
314
THE JOURNAL
Table l--Classification
Group 1 a) b) Group 2
Fig 4
5 years post-operative, bilateral active flexion of the IP joints is 35” (a: right thumb, b: left thumb).
and Idler, 1988; Isizaki et al, 1980; Kawai et al, 1976; Konno et al, 1978; Kiister, 1984; Linburg and Comstock, 1979; Miura, 1977; Miur’a, 1981; Murakami and Edashige, 1980; Salama and Weissman, 1975; Uchida et al, 1985; Uetake et al, 1977; Yoshioka and Yokoyama, 1980). Abnormalities of FPL can be further divided into four groups: a) absence (16 thumbs), b) abnormal connection (14 thumbs), c) anomalous insertion (14 thumbs), d) abnormal course (six thumbs). Simple abnormalities of FPL form the largest group, which are also of major interest in investigating our present case. Complete absence of FPL (Arminio, 1979; DeHaan et al, 1987; Fromont, 1895; Kiister, 1984; Miura, 1977; Strauch and Spinner, 1976; Tsuchida et al, 1976; Uchida et al, 1985) is the most common manifestation of this abnormality, followed by abnormal connection (Elsahy, 1976; Isizaki et al, 1980; Kawai et al, 1976; Linburg and Comstock, 1979; Murakami and Edashige, 1980; Rayan, 1984; Salama and Weissman, 1975; Uetake et al, 1977) and anomalous insertion (Blair and Omer, 1981; Hagan and Idler, 1988; Kawai et al, 1976; Kitayama and Kawakami, 1982; Konno et al, 1978; Miura, 198 1; Rayan, 1984; Tupper, 1969; Yoshioka and Yokoyama, 1980). The most frequently observed anomalous insertion was into the transverse
OF HAND
SURGERY
VOL. 18B No. 3 JUNE
1993
of 46 thumbs reported in literature
Absence Anomalous insertion
2 thumbs 1 thumb
b + c) Abnormal connection and anomalous insertion c+ d) Malposition and anomalous insertion
2 thumbs 6 thumbs
Group 3
a) ?
Absence
7 thumbs 4 thumbs
Group 4
a)
Absence
2 thumbs
Group 5
a) b) c)
Absence Abnormal connection Anomalous insertion
5 thumbs 12 thumbs 5 thumbs
carpal ligament, with four thumbs, followed by insertion of a bifurcated accessory tendon into the extensor or dorsal aponeuroses. In the case we describe, the insertion site of the flexor pollicis longus extended onto the proximal phalanx, causing an inability to flex the IP joint. This can be interpreted in two ways. The anomalous insertion can be considered to be a primary disorder, or the extremely limited pre-operative passive movement in the IP joint and the surgical findings can be interpreted to suggest an initial congenital hypoplasia of the joint itself causing a secondary manifestation in the form of anomalous insertion of the tendon. Our case fits into section c) of Group 5 (Table l), but one of the bifurcated tendons exhibited very similar abnormalities to those found in Group 2 (Rayan, 1984). Reports of similar abnormalities were not found among cases in Groups 4 or 5. References ARMINIO, J. A. (1979). Congenital anomaly of the thumb: Absent flexor pollicis longus tendon. Journal of Hand Surgery, 4: 5: 487-488. BLAIR, W. F. and OMER, G. E. (1981). Anomalous insertion of the flexor pollicis longus. Journal of Hand Surgery, 6: 3: 241-244. DeHAAN, M. R., WONG, L. B. and PETERSEN, D. P. (1987). Congenital anomaly of the thumb: Aplasia of the flexor pollicis longus. Journal of Hand Surgery, 12A: 1: 108-109. ELSAHY, N. I. (1976). Abnormal flexor pollicis longus sheath: Case report. Acta Chirurgica Plastica, 18: 1: 40-42. FROMONT (1895). Anomalies musculaires multiples de la main. Absence du flkhisseur propre du pouce. Absence des muscles de l’eminence thenar. Lombricaux supplCmentaires. Bulletins de la Sock% Anatamoque de Paris, 9: 395-401. HAGAN, H. .I. and IDLER, R. S. (1988). Limitation of thumb flexion due to an unusual insertion of the flexor pollicis longus. Journal of Hand Surgery, 13B: 4: 474-476. ISIZAKI, T., OMIYA, K. and SANKI, T. (1980). Congenital 4/5 metacarpal fusion accompanied with anomalous tendon slip from FPL to FDP (II): Report of two cases. Orthopedic Surgery, (Japan) 31: 12: 1649-1652. KAWAI, M., YOSIDA, K. and FUJITA, K. (1976). Congenital malposition of the flexor pollicis longus. Orthopedic Surgery (Japan), 27: 13: 1484-1485. KITAYAMA, Y. and KAWAKAMI, S. (1982). Anomaly of the flexor pollicis longus tendon associated with anomaly of the adductor pollicis muscle: A case report. Clinical Orthopedic Surgery (Japan), 17: 7: 735-739. KONNO, T., KAMESITA, K. and TAKAZAWA, H. (1978). Anomaly of flexor pollicis longus tendon: A case report. Orthopedic Surgery (Japan), 29: 13: 1574-1576. K&TER, G. (1984). Isolated aplasia of the flexor pollicis longus: A case report. Journal of Hand Surgery, 9A: 6: 870-871. LINBURG, R. M. and COMSTOCK, B. E. (1979). Anomalous tendon slips
315
FPL INSERTION from the flexor pollicis lcngus to the flexor digitorum profundus. Journal of Hand Surgery, 4: 1: 79-83. MICRA, T. (1977). Congenital absence of the flexor pollicis longus: A case report. The Hand, 9: 3: 272-274. MIURA, T. (1981). Congenital anomaly of the thumb: Unusual bifurcation of the flexor pollicis longus and its unusual insertion. Journal of Hand Surgery, 6: 6: 613-615. MURAKAMI, Y. and EDASHIGE, K. (1980). Anomalous flexor pollicis longus muscle. The Hand, 12: 1: X2-84. RAYAN, G. M. (1984). Congenital hypoplastic thumb with absent thenar muscles: Anomalous digital neurovascular bundle. Journal of Hand Surgery, 9A: 5: 665-668. SALAMA, R. and WEISSMAN, S. L. (1975). Congenital bilateral anomalous band between flexor and extensor pollicis longus tendon. Report of a case. The Hand, 7: 1: 25-26. STRAUCH, B. and SPINNER, M. (1976). Congenital anomaly of the thumb: Absent intrinsics and flexor pollicis longus. Journal of Bone and Joint Surgery, 58A: 1: 115-118. TSUCHIDA, Y., KASAI, S. and KOJIMA, T. (1976). Congenital absence of
flexor poliicis !ongus and flexor poilicis brevis. A case report. The Hand, 8: 3: 294-297. TUPPER, J. W. (1969). Pollex abductus due to congemtal malposition of the flexor pollicis longus. Journal of Bone and Joint Surgery, 5lA: 7: 1285-1290. UCHIDA, M., KOJIMA, T. and SAKURAI, N. (i985). Congenital absence of flexor pollicis longus without hypoplasia of thenar muscles. Plastic and Reconstructive Surgery; 75: 3: 413-416. UETAKE, M., TSUCHIYA, I., YAMAMOTO, R., KI’4NNO: T. and KAMATA, M. (1977). Anomalous tendon slip from theflexor polhcis longus to the flexor digitorum profundus. Orthopedic surgery (Japan), 28: 13: 1497-1499. YOSHIOKA, Y. and YOKOYAMA; M. (1980). Congemtal absence of the flexor pollicis longus: A case report. Central Japan Journal of Orthopedic Surgery, 23: 6: i660-1662.
Accepted: 30 December 1991 Junji Nakamura, MD, Department of Plastic and Reconstructive Surgery. Tokyo Koseinenkm Hospital 5-1, Tsnkudo-cho Shinjuku-ku, Tokyo i62, Japan. 0 1993 The British Society for Surgery of the Hand