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Congenital constriction band syndrome causing ulnar nerve palsy: Early diagnosis and surgical release with long-term follow-up
Congenital Constriction Band Syndrome Causing Ulnar Nerve Palsy: Early Diagnosis and Surgical Release With Long-Term Follow-up Neil F. Jones, MD, Andrew D. Smith, MD, Marc H. Hedrick, MD, Los Angeles, CA Three children with congenital constriction band syndrome affecting their upper extremities demonstrated clinical and electrophysiologic signs of a complete ulnar nerve palsy. Two of the children were diagnosed immediately postpartum with the subtle findings of an intrinsic minus posture of their hand and inability to actively extend their fingers at the proximal interphalangeal joints. One child had at least 5.5 months of intrauterine compression of the ulnar nerve detected by ultrasound examination at 18 weeks. Despite early release of the constriction bands, at 3 months in 2 children and at 6 months in 1 child, the ulnar nerve palsies persisted for a mean follow-up period of 7 years. If clinical examination of an infant with constriction band syndrome is indicative of a complete ulnar nerve palsy, the constriction band should be released as early as possible. If surgical exploration reveals significant compression of the ulnar nerve, consideration should be given to excising the involved segment of nerve with immediate primary nerve repair or nerve grafting because even early release of the constriction band does not seem to result in neurologic improvement in long-term follow-up studies. (J Hand Surg 2001;26A:467– 473. Copyright © 2001 by the American Society for Surgery of the Hand.) Key words: Congenital constriction band syndrome, ulnar nerve palsy.
Congenital constriction band syndrome occurs sporadically, with a reported incidence of between 1 in 1,200 and 1 in 15,000 live births.1–3 It can affect any anatomic location, but involvement of the exFrom the UCLA Hand Center, Division of Plastic and Reconstructive Surgery, and Department of Orthopedic Surgery, University of California, Los Angeles, CA. Received for publication July 5, 2000; accepted in revised form December 19, 2000. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: Neil F. Jones, MD, UCLA Hand Center, 200 UCLA Medical Plaza, Suite 140, Los Angeles, CA 90095. Copyright © 2001 by the American Society for Surgery of the Hand 0363-5023/01/26A03-0013$35.00/0 doi:10.1053/jhsu.2001.24130
tremities is more common. Congenital constriction band syndrome is considered a separate category (VI) in Swanson’s classification of congenital malformations.4 The degree of external constriction of an extremity is variable, ranging in severity from constriction rings to complete amputations.5–7 Isacsohn et al8 have developed a classification system based on the depth of involvement: (1) shallow groove in the skin, (2) down to subcutaneous tissue and muscle, (3) down to bone, (4) bony pseudarthrosis, and (5) intrauterine amputation. Initially, there may be just disruption of subcutaneous fat and skin. Increasing depth can result in significant vascular compromise to the distal extremity as decreased lymphatic outflow, edema, and veThe Journal of Hand Surgery 467
468 Jones, Smith, and Hedrick / Constriction Band Causing Ulnar Nerve Palsy
nous congestion ensue. Finally, ischemia and amputation may result. Involvement of one or more peripheral nerves due to congenital constriction band syndrome is rare.9 –18 We report 3 children in whom congenital constriction band syndrome of the upper extremity resulting in ulnar nerve palsy was diagnosed soon after birth. Despite earlier release of the constriction bands than described in most of the previous reports, the ulnar nerve palsies persisted in long-term follow-up studies.
Case Reports Patient 1 An infant was born at full term after an uncomplicated pregnancy with severe anomalies caused by congenital constriction band syndrome, including a 7 ⫻ 7 cm composite defect at the vertex of the scalp and skull, a complete amputation of the left arm at the level of the deltoid insertion of the humerus, and a constriction band at the supracondylar level of the right upper arm (Fig. 1A). The dural defect was reconstructed and the scalp defect was closed with multiple advancement flaps on the first day of life. The posture of the baby’s right hand showed clawing at the metacarpophalangeal (MCP) joints and he did not spontaneously extend the fingers at the proximal interphalangeal (PIP) joints, suggesting the possibility of an ulnar nerve palsy. Electromyography (EMG) of the right upper extremity showed activity in the flexor carpi ulnaris muscle, but no other electrical activity in the ulnar nerve distribution distal to the elbow. The median and radial nerves had normal conduction velocities and normal distal motor and sensory latencies. The child showed no clinical improvement by 3 months of age and therefore underwent surgical exploration. The ulnar nerve was severely compressed by the constriction band against the underlying medial intermuscular septum, but was normal in size and appearance proximal and distal to this zone (Fig. 1B). Intraoperative nerve stimulation proximal to the site of compression resulted only in contraction of the flexor carpi ulnaris muscle. Stimulation distal to the site of compression did not elicit any intrinsic muscle contraction in the hand. Neurolysis of the epineurium was performed under the operating microscope in conjunction with a hemicircumferential multiple Z-plasty of the skin and subcutaneous defect after excision of the constriction band. The infant continued to have an intrinsic minus
posture of his right hand, and repeat EMG at 1 year showed no electrical activity in the ulnar nerve below the elbow. Excision of the remaining half of the constriction band was performed with multiple Zplasty release at 14 months of age. Follow-up clinical examinations and EMG did not show any further improvement. Standard tendon transfers were suggested, but were declined by the parents. At the 9-year follow-up examination the child had a functional right hand and subjectively could discriminate “normal” sensation in the small finger and ulnar half of the ring finger; however, the ulnar nerve palsy persisted, with typical clawing of the fingers and inability to extend the fingers at the PIP joints (Fig. 1C).
Patient 2 Obstetrical ultrasound examination at 18 weeks in a 22-year-old mother showed an increase in the thickness of the subcutaneous tissues around the left forearm of the fetus. This extended proximally to a point midway between the elbow and hand with the depth from skin to radius of 8 mm. The left hand was noted to move freely. There was no ultrasound evidence of any other defects related to constriction banding. A second ultrasound examination at 24 weeks revealed a circumferential indentation of the subcutaneous tissues and muscle at the junction of the middle and distal thirds of the forearm. However, the edematous contour of the forearm and hand had resolved with a skin to radius depth of 5 mm. Ultrasound examination at 38 weeks confirmed the presence of a constriction band with reduced subcutaneous tissue and muscle mass in this zone. At full-term delivery, a deep constriction band was present around the distal third of the left forearm (Fig. 2A), but both flexor tendon and extrinsic extensor tendon function was completely normal. The infant was unable to actively extend his fingers at the PIP joints, however, and there was clawing at the MCP joints indicating a possible ulnar nerve palsy. The child underwent surgical exploration at 3 months of age and was found to have significant and discrete compression of the ulnar nerve at the site of the constriction band (Fig. 2B). An epineurial neurolysis of the ulnar nerve was performed. The constriction band was completely excised circumferentially, followed by multiple Z-plasties of the skin and subcutaneous tissues. Unfortunately, there was no resolution of the ulnar nerve palsy as evidenced by persistent clawing posture of the fingers 5 years after surgery (Fig. 2C).
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 469
Figure 1. (A) Patient 1. Congenital constriction band syndrome causing amputation of the left upper arm and a constriction band of the right upper arm with clawing of the fingers indicative of an ulnar nerve palsy. (B) Intraoperative view showing the fibrous band compressing the ulnar nerve. (C) Nine years after multiple Z-plasty release and neurolysis of the ulnar nerve, the right hand still shows the intrinsic minus posture of an ulnar nerve palsy.
470 Jones, Smith, and Hedrick / Constriction Band Causing Ulnar Nerve Palsy
Figure 2. (A) Patient 2. Constriction band of the distal left forearm with associated ulnar nerve palsy evident by clawing of the fingers. (B) Early release of the constriction band at 3 months of age revealed significant narrowing of the ulnar nerve at the level of the band. Interestingly, the median nerve appeared relatively normal. (C) Five years after neurolysis of the ulnar nerve and multiple Z-plasty release, the ulnar nerve palsy in the hand persists with fixed flexion contractures at the PIP joints.
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 471
Tendon transfers were discussed with the family, but were declined.
Patient 3 An 8-year-old girl was seen for evaluation of congenital constriction band syndrome of the distal right forearm. According to her parents, the ring and small fingers were comparatively small at birth with decreased sensation and mobility. Two-stage Z-plasty release was performed at 6 and 12 months of age without resolution of the symptoms, except that the
fingers grew in size. Examination 7.5 years after surgery revealed a mild constriction at the site of the surgical incision and signs of an ulnar nerve palsy in the hand with mild clawing of the ring and small fingers, atrophy of the intrinsic muscles, and decreased light touch sensation and 2-point discrimination in the small finger (Fig. 3A, B). Electromyography and nerve conduction studies showed a complete ulnar nerve palsy distal to the band with innervation of the ulnar side of the ring finger provided by the median nerve. Median and radial nerve functions
Figure 3. (A and B) Patient 3. Eight years after 2-stage multiple Z-plasty release of the constriction band of the distal right forearm, this girl’s hand still demonstrates slight clawing of the fingers and intrinsic muscle atrophy.
472 Jones, Smith, and Hedrick / Constriction Band Causing Ulnar Nerve Palsy
were normal. Tendon transfers were not considered necessary.
Discussion Major sensory and/or motor dysfunction caused by compression of a peripheral nerve by a congenital constriction band is rare. Sensory disturbances are difficult to diagnose in a baby or young infant and may be underreported in the literature. Barenberg and Greenberg9 first reported anesthesia distal to a constriction band just above the ankle with improved perception to pinprick 6 months after excision of the band. A child with a similar constriction band at the junction of the upper and middle thirds of the lower leg, however, with associated anesthesia distal to the band still developed a trophic ulcer of the heel despite 2-stage Z-plasty release.10 Moses et al11 described decreased sensation to light touch and pinprick or decreased temperature discrimination, vibration sense, or 2-point discrimination in 23% of 45 patients with congenital constriction band syndrome, but did not provide details regarding whether sensation improved after 2-stage excision of the band. Only 9 cases of a congenital constriction band causing compression of a peripheral nerve resulting in muscle weakness or complete paralysis have been reported.12–18 Motor dysfunction is more likely to be diagnosed in an infant than a sensory neuropathy. Meyer and Cummins12 first described a newborn baby with wrist drop associated with a congenital constriction band involving the upper arm. The radial nerve palsy did not resolve after early release of the band. A newborn baby with a radial nerve palsy associated with an area of cutis aplasia (which may be a variant of constriction band syndrome) of the dorsal forearm had spontaneous recovery after excision and skin grafting 2 weeks after birth.13 Weeks14 described motor dysfunction of the median, ulnar, and radial nerves caused by a constriction band of the upper arm. Despite 2-stage release of the constriction band 3 and 9 weeks after birth, there was no improvement and the child subsequently underwent nerve grafting of the radial nerve and decompression of the median and ulnar nerves at 12 months of age, but still did not demonstrate any postoperative improvement in radial nerve function over the ensuing 15 months. A similar constriction ring above the elbow causing total palsy of the median, ulnar, and radial nerves was treated by staged Z-plasty release at 10 months but required nerve grafting of the median and ulnar nerves at 5 years of age.15 Rich-
ardson and Humphrey16 described a child with radial nerve palsy associated with a constriction band treated by exploration and neurolysis of the radial nerve at 18 months of age; the child also had a poor result and required secondary tendon transfers. Uchida and Sugioka17 reported 3 cases of peripheral nerve palsy caused by a constriction band proximal to the wrist: 2 children had involvement of the median and ulnar nerves and 1 had an ulnar nerve palsy. All 3 children underwent late neurolysis and multiple Z-plasty release at 22, 34, and 60 months of age, but there was no recovery of nerve function. Finally, Weinzweig and Barr18 described a complete radial nerve palsy and incomplete median and ulnar nerve palsies caused by constriction band syndrome, treated by circumferential excision of the entire band and external neurolysis of all 3 nerves together with multiple Z-plasty release in a single procedure at 3.5 months of age. Follow-up examination 4 years after surgery revealed “slow but progressive clinical and electrophysiological improvement in all involved nerves.” The 3 children in our series with ulnar nerve palsy caused by congenital constriction band syndrome illustrate the extreme importance of early recognition of nerve palsies associated with constriction bands. This implies that all children with constriction band syndrome affecting an extremity should undergo a complete neurologic examination of the distal extremity. Children born with constriction band syndrome involving the upper extremity should be examined specifically for any associated peripheral nerve palsy affecting the median, ulnar, or radial nerves. Detection of weak or absent wrist and finger extension indicative of a radial nerve palsy is probably much easier than diagnosis of a median or ulnar nerve palsy in an infant. An ulnar nerve palsy is particularly difficult to diagnose in newborns, but based on these 3 children it should be strongly suspected if infant’s hands adopt an intrinsic minus deformity with clawing of the fingers and if they are not observed to extend their fingers at the PIP joints. Perhaps it should be mandatory for a hand surgeon to examine any baby born with a constriction band at or proximal to the wrist crease. Two of the 3 children in this study are notable in that they were both examined by a hand surgeon and diagnosed with ulnar nerve palsy on their first day of life. Both infants had clawing of their fingers and were not seen to be able to extend their fingers at the PIP joints, suggestive of an ulnar nerve palsy immediately postpartum. In the second child an ultrasound
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 473
examination had detected a constriction band as early as 18 weeks of gestation; this would translate into intrauterine compression of the ulnar nerve for at least 22 weeks by the time the infant was delivered at full term.19 Seven of the 9 previously reported cases of peripheral nerve palsy associated with congenital constriction band syndrome failed to show any improvement after release of the band and neurolysis of the involved nerve performed at 3 weeks, and at 6, 10, 18, 22, 34, and 60 months of age.12,14 –17 Only 2 children showed improvement, 1 after early excision and skin grafting 2 weeks after birth13 and the other after early release and neurolysis at 3.5 months of age.18 However, the 3 children in our series failed to show any neurologic improvement despite early release and neurolysis at 3 months (2 children) and early release alone at 6 months (1 child). Therefore, by combining our series of 3 children with peripheral nerve palsy caused by congenital constriction band syndrome with the 9 previously reported cases, 10 of the 12 children (83%) did not show any neurologic improvement after conventional treatment by multiple Z-plasty release and neurolysis of the involved nerve. These unsatisfactory results after standard early release of the constriction band and neurolysis of the involved nerve perhaps suggest the need for a more radical strategy of excising the discrete area of compressed nerve, followed by immediate primary nerve repair or nerve grafting under the operating microscope. The ultrasound evidence in our second child suggests that even an ulnar nerve palsy due to constriction band syndrome diagnosed immediately postpartum may have been present for at least 5.5 months in utero. Even early release of the band and microneurolysis of the nerve at 3 months (but which may represent at least 8.5 months by a combination of in utero and postpartum compression), however, did not result in neurologic improvement in long-term follow-up analysis. The fixed PIP joint flexion contractures seen in this second child may reflect the significant period of intrauterine compression. Therefore, if a newborn with congenital constriction band syndrome is suspected of having an associated ulnar nerve palsy, based on the subtle findings of an intrinsic minus posture of the hand, it may be more logical to intervene surgically as early as possible by multiple Z-plasty release of the constriction band. If surgical exploration reveals severe flattening or constriction of the ulnar nerve, rather than just
performing a neurolysis of the ulnar nerve, the surgeon may want to consider excising the discrete involved segment of ulnar nerve followed by immediate primary nerve repair or nerve grafting, because conventional treatment by neurolysis does not seem to result in neurologic improvement in long-term follow-up studies.
References 1. Ossipoff V, Hall BD. Etiologic factors in the congenital constriction band syndrome: a study of 24 patients. Birth Defects Orig Artic Ser 1977;13:117–132. 2. Baker CJ, Rudolph AJ. Congenital ring constrictions and intrauterine amputations. Am J Dis Child 1971;121:393– 400. 3. Garza A, Cordero JF, Mulinare J. Epidemiology of the early amnion rupture spectrum of defects. Am J Dis Child 1988;142:541–544. 4. Swanson AB. A classification for congenital limb malformations. J Hand Surg 1976;1:8 –22. 5. Miura T. Congenital constriction band syndrome. J Hand Surg 1984;9A:82– 88. 6. Bourne MH, Klassen RA. Congenital annular constricting bands: review of the literature and a case report. J Pediatr Orthop 1987;7:218 –221. 7. Wiedrich TA. Congenital constriction band syndrome. Hand Clin 1998;14:29 –38. 8. Isacsohn M, Aboulafia Y, Horowitz B, Ben-Hur N. Congenital annular constrictions due to congenital constriction bands. Acta Obstet Gynecol Scand 1976;55:179 –182. 9. Barenberg LH, Greenberg B. Intrauterine amputations and constriction bands. Am J Dis Child 1942;64:87–92. 10. Blackfield HM, Hause DP. Congenital constricting bands of the extremities. Plast Reconstr Surg 1951;8:101–109. 11. Moses JM, Flatt AE, Cooper RR. Annular constricting bands. J Bone Joint Surg 1979;61A:562–565. 12. Meyer H, Cummins H. Severe maternal trauma in early pregnancy. Am J Obstet Gynecol 1941;42:150 –153. 13. Pers M. Congenital absence of skin: pathogenesis and relation to ring-constriction. Acta Chir Scand 1963;126: 388 –396. 14. Weeks PM. Radial, median, and ulnar nerve dysfunction associated with a congenital constricting band of the arm. Plast Reconstr Surg 1982;69:333–336. 15. Tada K, Yonenobu K, Swanson AB. Congenital constriction band syndrome. J Pediatr Orthop 1984;4:726 –730. 16. Richardson GA, Humphrey MS. Congenital compression of the radial nerve. J Hand Surg 1989;14A:901–903. 17. Uchida Y, Sugioka Y. Peripheral nerve palsy associated with congenital constriction band syndrome. J Hand Surg 1991;16B:109 –112. 18. Weinzweig N, Barr A. Radial, ulnar, and median nerve palsies caused by a congenital constriction band of the arm: single-stage correction. Plast Reconstr Surg 1994;94:872– 876. 19. Hill LM, Kislak S, Jones NF. Prenatal ultrasound diagnosis of a forearm constriction band. J Ultrasound Med 1988;7: 293–295.
Congenital constriction band syndrome occurs sporadically, with a reported incidence of between 1 in 1,200 and 1 in 15,000 live births.1–3 It can affect any anatomic location, but involvement of the exFrom the UCLA Hand Center, Division of Plastic and Reconstructive Surgery, and Department of Orthopedic Surgery, University of California, Los Angeles, CA. Received for publication July 5, 2000; accepted in revised form December 19, 2000. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: Neil F. Jones, MD, UCLA Hand Center, 200 UCLA Medical Plaza, Suite 140, Los Angeles, CA 90095. Copyright © 2001 by the American Society for Surgery of the Hand 0363-5023/01/26A03-0013$35.00/0 doi:10.1053/jhsu.2001.24130
tremities is more common. Congenital constriction band syndrome is considered a separate category (VI) in Swanson’s classification of congenital malformations.4 The degree of external constriction of an extremity is variable, ranging in severity from constriction rings to complete amputations.5–7 Isacsohn et al8 have developed a classification system based on the depth of involvement: (1) shallow groove in the skin, (2) down to subcutaneous tissue and muscle, (3) down to bone, (4) bony pseudarthrosis, and (5) intrauterine amputation. Initially, there may be just disruption of subcutaneous fat and skin. Increasing depth can result in significant vascular compromise to the distal extremity as decreased lymphatic outflow, edema, and veThe Journal of Hand Surgery 467
468 Jones, Smith, and Hedrick / Constriction Band Causing Ulnar Nerve Palsy
nous congestion ensue. Finally, ischemia and amputation may result. Involvement of one or more peripheral nerves due to congenital constriction band syndrome is rare.9 –18 We report 3 children in whom congenital constriction band syndrome of the upper extremity resulting in ulnar nerve palsy was diagnosed soon after birth. Despite earlier release of the constriction bands than described in most of the previous reports, the ulnar nerve palsies persisted in long-term follow-up studies.
Case Reports Patient 1 An infant was born at full term after an uncomplicated pregnancy with severe anomalies caused by congenital constriction band syndrome, including a 7 ⫻ 7 cm composite defect at the vertex of the scalp and skull, a complete amputation of the left arm at the level of the deltoid insertion of the humerus, and a constriction band at the supracondylar level of the right upper arm (Fig. 1A). The dural defect was reconstructed and the scalp defect was closed with multiple advancement flaps on the first day of life. The posture of the baby’s right hand showed clawing at the metacarpophalangeal (MCP) joints and he did not spontaneously extend the fingers at the proximal interphalangeal (PIP) joints, suggesting the possibility of an ulnar nerve palsy. Electromyography (EMG) of the right upper extremity showed activity in the flexor carpi ulnaris muscle, but no other electrical activity in the ulnar nerve distribution distal to the elbow. The median and radial nerves had normal conduction velocities and normal distal motor and sensory latencies. The child showed no clinical improvement by 3 months of age and therefore underwent surgical exploration. The ulnar nerve was severely compressed by the constriction band against the underlying medial intermuscular septum, but was normal in size and appearance proximal and distal to this zone (Fig. 1B). Intraoperative nerve stimulation proximal to the site of compression resulted only in contraction of the flexor carpi ulnaris muscle. Stimulation distal to the site of compression did not elicit any intrinsic muscle contraction in the hand. Neurolysis of the epineurium was performed under the operating microscope in conjunction with a hemicircumferential multiple Z-plasty of the skin and subcutaneous defect after excision of the constriction band. The infant continued to have an intrinsic minus
posture of his right hand, and repeat EMG at 1 year showed no electrical activity in the ulnar nerve below the elbow. Excision of the remaining half of the constriction band was performed with multiple Zplasty release at 14 months of age. Follow-up clinical examinations and EMG did not show any further improvement. Standard tendon transfers were suggested, but were declined by the parents. At the 9-year follow-up examination the child had a functional right hand and subjectively could discriminate “normal” sensation in the small finger and ulnar half of the ring finger; however, the ulnar nerve palsy persisted, with typical clawing of the fingers and inability to extend the fingers at the PIP joints (Fig. 1C).
Patient 2 Obstetrical ultrasound examination at 18 weeks in a 22-year-old mother showed an increase in the thickness of the subcutaneous tissues around the left forearm of the fetus. This extended proximally to a point midway between the elbow and hand with the depth from skin to radius of 8 mm. The left hand was noted to move freely. There was no ultrasound evidence of any other defects related to constriction banding. A second ultrasound examination at 24 weeks revealed a circumferential indentation of the subcutaneous tissues and muscle at the junction of the middle and distal thirds of the forearm. However, the edematous contour of the forearm and hand had resolved with a skin to radius depth of 5 mm. Ultrasound examination at 38 weeks confirmed the presence of a constriction band with reduced subcutaneous tissue and muscle mass in this zone. At full-term delivery, a deep constriction band was present around the distal third of the left forearm (Fig. 2A), but both flexor tendon and extrinsic extensor tendon function was completely normal. The infant was unable to actively extend his fingers at the PIP joints, however, and there was clawing at the MCP joints indicating a possible ulnar nerve palsy. The child underwent surgical exploration at 3 months of age and was found to have significant and discrete compression of the ulnar nerve at the site of the constriction band (Fig. 2B). An epineurial neurolysis of the ulnar nerve was performed. The constriction band was completely excised circumferentially, followed by multiple Z-plasties of the skin and subcutaneous tissues. Unfortunately, there was no resolution of the ulnar nerve palsy as evidenced by persistent clawing posture of the fingers 5 years after surgery (Fig. 2C).
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 469
Figure 1. (A) Patient 1. Congenital constriction band syndrome causing amputation of the left upper arm and a constriction band of the right upper arm with clawing of the fingers indicative of an ulnar nerve palsy. (B) Intraoperative view showing the fibrous band compressing the ulnar nerve. (C) Nine years after multiple Z-plasty release and neurolysis of the ulnar nerve, the right hand still shows the intrinsic minus posture of an ulnar nerve palsy.
470 Jones, Smith, and Hedrick / Constriction Band Causing Ulnar Nerve Palsy
Figure 2. (A) Patient 2. Constriction band of the distal left forearm with associated ulnar nerve palsy evident by clawing of the fingers. (B) Early release of the constriction band at 3 months of age revealed significant narrowing of the ulnar nerve at the level of the band. Interestingly, the median nerve appeared relatively normal. (C) Five years after neurolysis of the ulnar nerve and multiple Z-plasty release, the ulnar nerve palsy in the hand persists with fixed flexion contractures at the PIP joints.
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 471
Tendon transfers were discussed with the family, but were declined.
Patient 3 An 8-year-old girl was seen for evaluation of congenital constriction band syndrome of the distal right forearm. According to her parents, the ring and small fingers were comparatively small at birth with decreased sensation and mobility. Two-stage Z-plasty release was performed at 6 and 12 months of age without resolution of the symptoms, except that the
fingers grew in size. Examination 7.5 years after surgery revealed a mild constriction at the site of the surgical incision and signs of an ulnar nerve palsy in the hand with mild clawing of the ring and small fingers, atrophy of the intrinsic muscles, and decreased light touch sensation and 2-point discrimination in the small finger (Fig. 3A, B). Electromyography and nerve conduction studies showed a complete ulnar nerve palsy distal to the band with innervation of the ulnar side of the ring finger provided by the median nerve. Median and radial nerve functions
Figure 3. (A and B) Patient 3. Eight years after 2-stage multiple Z-plasty release of the constriction band of the distal right forearm, this girl’s hand still demonstrates slight clawing of the fingers and intrinsic muscle atrophy.
472 Jones, Smith, and Hedrick / Constriction Band Causing Ulnar Nerve Palsy
were normal. Tendon transfers were not considered necessary.
Discussion Major sensory and/or motor dysfunction caused by compression of a peripheral nerve by a congenital constriction band is rare. Sensory disturbances are difficult to diagnose in a baby or young infant and may be underreported in the literature. Barenberg and Greenberg9 first reported anesthesia distal to a constriction band just above the ankle with improved perception to pinprick 6 months after excision of the band. A child with a similar constriction band at the junction of the upper and middle thirds of the lower leg, however, with associated anesthesia distal to the band still developed a trophic ulcer of the heel despite 2-stage Z-plasty release.10 Moses et al11 described decreased sensation to light touch and pinprick or decreased temperature discrimination, vibration sense, or 2-point discrimination in 23% of 45 patients with congenital constriction band syndrome, but did not provide details regarding whether sensation improved after 2-stage excision of the band. Only 9 cases of a congenital constriction band causing compression of a peripheral nerve resulting in muscle weakness or complete paralysis have been reported.12–18 Motor dysfunction is more likely to be diagnosed in an infant than a sensory neuropathy. Meyer and Cummins12 first described a newborn baby with wrist drop associated with a congenital constriction band involving the upper arm. The radial nerve palsy did not resolve after early release of the band. A newborn baby with a radial nerve palsy associated with an area of cutis aplasia (which may be a variant of constriction band syndrome) of the dorsal forearm had spontaneous recovery after excision and skin grafting 2 weeks after birth.13 Weeks14 described motor dysfunction of the median, ulnar, and radial nerves caused by a constriction band of the upper arm. Despite 2-stage release of the constriction band 3 and 9 weeks after birth, there was no improvement and the child subsequently underwent nerve grafting of the radial nerve and decompression of the median and ulnar nerves at 12 months of age, but still did not demonstrate any postoperative improvement in radial nerve function over the ensuing 15 months. A similar constriction ring above the elbow causing total palsy of the median, ulnar, and radial nerves was treated by staged Z-plasty release at 10 months but required nerve grafting of the median and ulnar nerves at 5 years of age.15 Rich-
ardson and Humphrey16 described a child with radial nerve palsy associated with a constriction band treated by exploration and neurolysis of the radial nerve at 18 months of age; the child also had a poor result and required secondary tendon transfers. Uchida and Sugioka17 reported 3 cases of peripheral nerve palsy caused by a constriction band proximal to the wrist: 2 children had involvement of the median and ulnar nerves and 1 had an ulnar nerve palsy. All 3 children underwent late neurolysis and multiple Z-plasty release at 22, 34, and 60 months of age, but there was no recovery of nerve function. Finally, Weinzweig and Barr18 described a complete radial nerve palsy and incomplete median and ulnar nerve palsies caused by constriction band syndrome, treated by circumferential excision of the entire band and external neurolysis of all 3 nerves together with multiple Z-plasty release in a single procedure at 3.5 months of age. Follow-up examination 4 years after surgery revealed “slow but progressive clinical and electrophysiological improvement in all involved nerves.” The 3 children in our series with ulnar nerve palsy caused by congenital constriction band syndrome illustrate the extreme importance of early recognition of nerve palsies associated with constriction bands. This implies that all children with constriction band syndrome affecting an extremity should undergo a complete neurologic examination of the distal extremity. Children born with constriction band syndrome involving the upper extremity should be examined specifically for any associated peripheral nerve palsy affecting the median, ulnar, or radial nerves. Detection of weak or absent wrist and finger extension indicative of a radial nerve palsy is probably much easier than diagnosis of a median or ulnar nerve palsy in an infant. An ulnar nerve palsy is particularly difficult to diagnose in newborns, but based on these 3 children it should be strongly suspected if infant’s hands adopt an intrinsic minus deformity with clawing of the fingers and if they are not observed to extend their fingers at the PIP joints. Perhaps it should be mandatory for a hand surgeon to examine any baby born with a constriction band at or proximal to the wrist crease. Two of the 3 children in this study are notable in that they were both examined by a hand surgeon and diagnosed with ulnar nerve palsy on their first day of life. Both infants had clawing of their fingers and were not seen to be able to extend their fingers at the PIP joints, suggestive of an ulnar nerve palsy immediately postpartum. In the second child an ultrasound
The Journal of Hand Surgery / Vol. 26A No. 3 May 2001 473
examination had detected a constriction band as early as 18 weeks of gestation; this would translate into intrauterine compression of the ulnar nerve for at least 22 weeks by the time the infant was delivered at full term.19 Seven of the 9 previously reported cases of peripheral nerve palsy associated with congenital constriction band syndrome failed to show any improvement after release of the band and neurolysis of the involved nerve performed at 3 weeks, and at 6, 10, 18, 22, 34, and 60 months of age.12,14 –17 Only 2 children showed improvement, 1 after early excision and skin grafting 2 weeks after birth13 and the other after early release and neurolysis at 3.5 months of age.18 However, the 3 children in our series failed to show any neurologic improvement despite early release and neurolysis at 3 months (2 children) and early release alone at 6 months (1 child). Therefore, by combining our series of 3 children with peripheral nerve palsy caused by congenital constriction band syndrome with the 9 previously reported cases, 10 of the 12 children (83%) did not show any neurologic improvement after conventional treatment by multiple Z-plasty release and neurolysis of the involved nerve. These unsatisfactory results after standard early release of the constriction band and neurolysis of the involved nerve perhaps suggest the need for a more radical strategy of excising the discrete area of compressed nerve, followed by immediate primary nerve repair or nerve grafting under the operating microscope. The ultrasound evidence in our second child suggests that even an ulnar nerve palsy due to constriction band syndrome diagnosed immediately postpartum may have been present for at least 5.5 months in utero. Even early release of the band and microneurolysis of the nerve at 3 months (but which may represent at least 8.5 months by a combination of in utero and postpartum compression), however, did not result in neurologic improvement in long-term follow-up analysis. The fixed PIP joint flexion contractures seen in this second child may reflect the significant period of intrauterine compression. Therefore, if a newborn with congenital constriction band syndrome is suspected of having an associated ulnar nerve palsy, based on the subtle findings of an intrinsic minus posture of the hand, it may be more logical to intervene surgically as early as possible by multiple Z-plasty release of the constriction band. If surgical exploration reveals severe flattening or constriction of the ulnar nerve, rather than just
performing a neurolysis of the ulnar nerve, the surgeon may want to consider excising the discrete involved segment of ulnar nerve followed by immediate primary nerve repair or nerve grafting, because conventional treatment by neurolysis does not seem to result in neurologic improvement in long-term follow-up studies.
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