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Late Deformities Following the Transfer of the Flexor Carpi Ulnaris to the Extensor Carpi Radialis Brevis in Children With Cerebral Palsy
SCIENTIFIC ARTICLE
Late Deformities Following the Transfer of the Flexor Carpi Ulnaris to the Extensor Carpi Radialis Brevis in Children With Cerebral Palsy J. Megan M. Patterson, MD, Angela A. Wang, MD, Douglas T. Hutchinson, MD
Purpose The transfer of flexor carpi ulnaris (FCU) to extensor carpi radialis brevis (ECRB) (the Green transfer) in children with cerebral palsy (CP) is a surgical option frequently used to address the typical wrist flexion deformity that is often present in these patients. We hypothesize that late deformities may occur when these transfers are performed in patients before skeletal maturity. The purpose of this investigation was to determine the frequency of these deformities and the factors that influence their development. Methods We performed 41 FCU to ECRB tendon transfers in children with CP at our institution between 1987 and 2005 and retrospectively reviewed them. A total of 24 patients with 25 transfers had a minimum 2-year follow-up and were included in the study population. We identified patients who developed a late deformity after tendon transfer. We analyzed medical records of these patients to identify factors associated with the development of a deformity. Results Of the 25 transfers, 12 developed a late deformity between 10 and 105 months postoperatively. The deformities that developed were extension deformities (8), supination deformities (one), and recurrent flexion deformities (3). Of the 12 patients with deformity, 9 required revision surgeries. Of these 12 patients, 9 who were less than 13 years of age at the time of transfer developed a late deformity, compared with 3 who were older than 13 years of age. Conclusions The FCU to ECRB tendon transfer remains a viable option to address the wrist flexion deformity seen in patients with CP. Care should be taken when performing this tendon transfer in patients less than 13 years of age because they may develop a postoperative deformity, commonly an extension deformity. We believe that these deformities develop when the patient enters a growth spurt and the transferred muscle-tendon unit does not lengthen at the same rate as the involved upper extremity. (J Hand Surg 2010;35A:1774–1778. Copyright © 2010 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Cerebral palsy, deformity, Green transfer, tendon transfer. is a nonprogressive disorder of the central nervous system that can involve the upper limb, the lower limb, or both.1–3 Although CP is a static disorder, the limb deformity often changes with growth and contractures may worsen as
C
EREBRAL PALSY (CP)
From the Department of Orthopaedics, University of North Carolina School of Medicine, Chapel Hill, NC; and the Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT. Received for publication January 8, 2010; accepted in revised form July 8, 2010. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
1774 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
the child gets older.3 Upper extremity involvement typically includes adduction and internal rotation of the shoulder, flexion of the elbow, pronation of the forearm, flexion of the wrist and fingers, swan neck deformities of the fingers, and a thumb in palm deformity. Corresponding author: J. Megan M. Patterson, MD, Department of Orthopaedics, UNC School of Medicine, 3135 Bioinformatics Bldg, CB 7055, Chapel Hill, NC 27599; e-mail: [email protected]. 0363-5023/10/35A11-0006$36.00/0 doi:10.1016/j.jhsa.2010.07.014
LATE DEFORMITIES AFTER GREEN TRANSFER FOR CP
Wrist involvement in CP has both functional and aesthetic implications. An abnormal flexion and extension arc of the wrist interferes with the digital grasp and release. A severely flexed posture of the wrist can cause difficulties with hygiene and is aesthetically unappealing to many patients and families. Transfer of flexor carpi ulnaris (FCU) to extensor carpi radialis brevis (ECRB) (the Green transfer) in children with CP has been used for a number of years to address the typical wrist flexion deformity often seen in these patients.4–9,13 Postoperative deformities after this tendon transfer have been reported to occur in 13% to 69% of patients.6 – 8 We believe that late deformities from length or tension changes occurring with growth may result when these transfers are performed in patients before skeletal maturity. The purpose of this investigation was to determine the frequency of these deformities and the factors that influence their development. MATERIALS AND METHODS After we obtained institutional review board approval, we retrospectively reviewed the charts of all patients with CP who had an FCU to ECRB tendon transfer performed at our institution between 1987 and 2005. We identified 41 transfers performed in 40 patients. We excluded from our study 16 of these transfers in 16 patients owing to inadequate follow-up. A total of 24 patients with 25 transfers had a minimum 2-year follow-up and comprised our study population. There were 11 male and 13 female patients, with an average age of 12 years at the time of their tendon transfer (range, 4 –18 y). The extent of CP involvement varied from quadriplegia in 7 patients to hemiplegia in 17 patients; 2 patients also had an athetoid component. The procedures were performed on the left upper extremity in 7 patients and the right upper extremity in 16 patients, and one patient had bilateral procedures performed. Follow-up averaged 5 years, 8 months (range, 2 y to 11 y, 3 mo). We analyzed medical records of all patients in the study group to determine factors associated with the development of late deformity after tendon transfer. We evaluated the extent of CP (quadriplegic and hemiplegic) and whether there was an athetoid component, the age at time of transfer, and the time when the deformity was noticed. We also noted any revision surgeries that were required. The surgical technique used for the FCU to ECRB tendon transfer was as described by Green and Banks.4 The transfer was tensioned between 0° and 30° of extension, although the tension at which the transfer was placed was not indicated in the surgical reports of
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9 of the 25 transfers studied. Five patients had isolated FCU to ECRB tendon transfers performed. Additional procedures were performed in 20 patients and consisted of abductor pollicis longus tenodesis (14), extensor pollicis brevis tenodesis (one), extensor pollicis longus rerouting (4), thumb intrinsic release (9), flexor digitorum superficialis and profundus lengthening (7), flexor pollicis longus lengthening (5), flexor carpi radialis lengthening (3), pronator release (4), pronator rerouting (6), palmaris longus release (1), and elbow release (3). All patients were immobilized in an above-elbow cast or splint for the first 4 to 6 weeks, after which they received a below-elbow splint for 3 months (1 mo full-time, 1 mo part-time, and 1 mo of nighttime use). The patients were immobilized with the wrist in neutral to 30° of extension and the forearm in neutral rotation while in the above-elbow splint or cast. The belowelbow splint also held the wrist in neutral to 30° of extension but did not restrict forearm rotation. Therapy was individualized for each patient but in general was not prescribed postoperatively. RESULTS From our study population, we identified 14 patients who developed a deformity in the surgical extremity after FCU to ECRB tendon transfer. Two of these deformities occurred in the immediate postoperative period, which we defined as the first 3 months after surgery, and were excluded from analysis. The remaining 12 deformities developed later in the postoperative course and were the focus of our investigation. Of the 25 transfers evaluated, 12 developed a late postoperative deformity. These patients had good positioning of their wrist until the development of their deformity, which was noted at an average of 38 months after their index procedure (range, 10 –105 mo). Eight patients developed an extension deformity, one developed a supination deformity, and 3 developed a recurrent flexion deformity. Of the 7 patients with quadriplegic CP, 5 developed a deformity, compared with only 7 of the 17 patients with hemiplegic CP. A late extension deformity occurred in one patient with an athetoid component. A total of 12 FCU to ECRB tendon transfers were performed in patients under the age of 13; of these patients, 9 developed a late postoperative deformity. In comparison, only 3 of the 12 patients who were 13 years or older at the time of their index procedure developed a late deformity (Fig. 1). At the time of surgery, the average age of patients who developed a late deformity was 10 years, 6 months, compared with
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FIGURE 1: Incidence of late deformities in patients with CP who underwent transfer of the FCU to the ECRB.
13 years, 9 months for patients who did not develop a deformity. Of the 12 patients with late deformity, 9 required revision surgeries to address problems with both function and aesthetics. Of the 8 patients who developed an extension deformity, 7 required a revision surgery to address their deformity. Revision procedures consisted of wrist arthrodesis (1 patient) and lengthening of the tendon transfer (6 patients). Of the 3 patients who developed a recurrent flexion deformity, 2 had revision surgery. One patient had a retensioning of the tendon transfer, and 1 patient had a wrist arthrodesis. Both of these revision surgeries were successful. DISCUSSION Transfer of FCU to ECRB has been used for many years to address the wrist flexion deformity commonly seen in patients with CP. Abnormal flexion and extension of the wrist interferes with the ability to use the tenodesis effect for digital grasp and release. This tendon transfer is successful because it removes the deforming force (wrist flexion and forearm pronation) and augments the desired force (wrist extension and forearm supination). Since Green’s original description in 19425 of the FCU tendon transfer in patients with CP, many authors have evaluated its efficacy and found that although it is an effective transfer to improve wrist extension, it is often associated with a postoperative hyperextension deformity.6 –11 Many factors can influence the development of a postoperative hyperextension deformity, such as FCU spasticity, the tension at which the transfer is placed, and poor postoperative compliance with immobilization and therapy. Hoffer et al. evaluated 38 patients with CP who had an FCU to ECRB tendon transfer with a minimum 8-year follow-up, and found that 13% developed a postoperative hyperextension deformity.6 Thometz and Tachdjian also reported on the long-term results of this tendon transfer in patients with
FIGURE 2: Clinical photograph of a boy 16 years, 4 months of age who underwent a right Green transfer at age 5 years, 9 months and developed a late extension deformity 8 years, 9 months postoperatively.
CP.8 They described 25 patients with a minimum 4-year follow-up and found that 9 patients developed a postoperative hyperextension deformity, although this was a functional problem only in patients who relied on wrist flexion for finger release. Wolf et al. evaluated 16 patients with CP who had an FCU to ECRB tendon transfer with a minimum 1-year follow-up, and found that postoperatively, 11 patients held the wrist in a position of extension, but that this did not interfere with function.7 In our study population, we found that late postoperative deformity occurred in 48% of patients, and the most common deformity that developed was an extension type (Fig. 2). Many studies have reported the incidence of late postoperative deformities, but a possible relationship between patients’ age at the time of surgery and the likelihood of developing a deformity has not been well studied. In our study, 82% of tendon transfers performed in patients under the age of 13 developed a late postoperative deformity, whereas only 25% of patients who were 13 years or older at the time of the index procedure had a similar outcome. The late deformities noted in our study developed an average of 38 months postoperatively (range, 10 –105 mo), often occurring after the family noted the patient undergoing a period of rapid growth. The adolescent growth spurt in normal children usually occurs between the ages of 10 and 14 in girls, and between the ages of 12 and 16 in boys.12–14 Growth studies in children with CP have shown that although their adolescent growth spurts are blunted, these patients have growth curves that are similar in
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shape to unaffected children.15 Current studies in the literature that describe late postoperative hyperextension deformities evaluated patients who ranged in age from 4 to 23 years. However, these studies do not specify the ages of patients who developed a hyperextension deformity and when these deformities occurred. We believe that this is a critical piece of information because we hypothesize that these late deformities occur when patients who underwent an FCU to ECRB tendon transfer at a young age enter the adolescent growth spurt, and the transferred musculotendinous unit does not grow and stretch at the same rate as the skeleton. We believe that scar tissue at the site of the transfer does not have the ability to stretch and adapt with rapid growth and thus contributes to the worsening deformity that is seen. In Green and Banks’ original description, the authors recommended that the transfer be performed when the patient is old enough to participate in therapy.4 Since then, different recommendations have been made regarding the optimal time for tendon transfer, ranging from as early as 4 years of age to as late as 12 years of age.1–3,9,16 It is recommended that surgery be delayed until motor patterns are established, the deformity is static, and patients are able to participate in postoperative therapy.2– 4 Concern has been raised that if surgery is delayed until the patient is older, bone deformity, muscle fibrosis, and joint contractures may occur.2,16 In addition, patients may have accepted the functional and cosmetic deformity and may no longer be interested in surgery.16 Beach et al. evaluated 40 patients with CP who underwent an FCU to ECRB tendon transfer with an average follow-up of 5 years, 3 months, and found that the best results were seen in patients who had the transfer between the ages of 7 and 12 years.9 Although patients older than 12 years of age showed functional improvement, it was not as great as the improvements seen in the group of patients who were less than 7 years of age, or those who were 7 to 12 years of age (71% improvement vs 83% and 86%, respectively). In that study, there was one postoperative supination deformity and one postoperative hyperextension deformity, both of which occurred in patients younger than 10 years of age. In our study, we found that patients under the age of 13 at the time of tendon transfer were much more likely to develop a postoperative deformity than patients who had transfers when they were older than 13 years of age (82% vs 25%). We agree that performing the tendon transfer when the patient is young may be indicated to improve the function and aesthetic appearance of the limb; however, it may place patients at a higher risk of postoperative deformity. We recommend
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that if this tendon transfer is performed before the age of 13, patients should have close follow-up throughout their growth spurt to monitor for the development of deformity. This is especially true for patients with spastic quadriplegia, because we found that these patients were more likely to develop a late postoperative deformity compared with patients with hemiplegic CP. All transfers in our study for which data were available were tensioned between neutral and 30° of extension. Green and Banks’ original description recommended that the transfer be placed such that the wrist is held in 45° of extension and full supination; in that series, the authors reported no patients developed an extension posture.4 Most other authors recommended that the transfer be tensioned between neutral and 20° of extension.3,6,9,17 We agree with these authors and feel that the FCU to ECRB tendon transfer should be tensioned in no more than 30° of extension because postoperative hyperextension deformities have been reported in patients whose transfers were tensioned in maximum extension.8,9 A challenge of any study that evaluates patients with CP is that the extent of deformity and limb involvement varies, as do the surgeries performed, which makes it difficult to compare patients within a study as well as between studies. The variability in both our patient population as well as the secondary procedures performed is a limitation of this study. We chose to include all patients with CP who had an FCU to ECRB tendon transfer in our study population regardless of the extent of disease involvement or whether the patients had additional procedures performed on the upper extremity because we believe this gives a more accurate representation of the true spectrum of the disease. An additional limitation of this study is possible follow-up bias. Patients who developed a postoperative deformity and who were unsatisfied with their result may have been more likely to return for further care. It is also possible that those patients who had surgery at a younger age may have had a more severe condition that may have made them more likely to develop a postoperative deformity. We acknowledge that there are likely multiple factors that contribute to the development of postoperative deformities after the transfer of FCU to ECRB, including failure of the transfer, overtensioning of the transfer, muscle spasticity, and dystonia. We hypothesize that age at the time of transfer and the patient’s growth likely have an important role given the high rate of late deformities seen in our younger patients. Further research evaluating the long-term outcomes of young children after tendon transfers is needed to help deter-
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mine the true risk of developing a late deformity in children with and without CP. Based on our findings, we believe that although FCU to ECRB tendon transfer remains a viable option to address the wrist flexion deformity commonly seen in patients with CP, its timing remains a balancing act. Performing this tendon transfer in skeletally immature patients may result in deformity as a result of muscle imbalance; nevertheless, it remains a better option for most patients than wrist arthrodesis or chondrodesis.2,18,19 Care should be taken when performing the procedure in patients under the age of 13 because we found that as much as 82% of these patients develop a late postoperative deformity, most commonly an extension deformity. Family education regarding the risk of late deformity should be part of the preoperative discussion, and these patients should be observed at regular intervals postoperatively until they reach skeletal maturity. REFERENCES 1. Skoff H, Woodbury DF. Current concepts review: management of the upper extremity in cerebral palsy. J Bone Joint Surg 1985;67A: 500 –503. 2. Mital MA, Sakellarides HT. Surgery of the upper extremity in the retarded individual with spastic cerebral palsy. Orthop Clin North Am 1981;12:127–141. 3. Goldner JL. Surgical reconstruction of the upper extremity in cerebral palsy. Hand Clin 1988;4:223–265. 4. Green WT, Banks HH. Flexor carpi ulnaris transplant and its use in cerebral palsy. J Bone Joint Surg 1962;44A:1343–1352. 5. Green WT. Tendon transplantation of the flexor carpi ulnaris for pronation-flexion deformity of the wrist. Surg Gynecol Obstet 1942; 75:337–342
6. Hoffer MM, Lehman M, Mitani M. Long-term follow-up on tendon transfers to the extensors of the wrist and fingers in patients with cerebral palsy. J Hand Surg 1986;11A:836 – 840. 7. Wolf TM, Clinkscales CM, Hamlin C. Flexor carpi ulnaris tendon transfers in cerebral palsy. J Hand Surg 1998;23B:340 –343. 8. Thometz JG, Tachdjian M. Long-term follow-up of the flexor carpi ulnaris transfer in spastic hemiplegic children. J Pediatr Orthop 1988;8:407– 412. 9. Beach WR, Strecker WB, Coe J, Manske PR, Schoenecker RL, Dailey L. Use of the Green transfer in treatment of patients with spastic cerebral palsy: 17 year experience. J Pediatr Orthop 1991; 11:731–736. 10. Roth JH, O’Grady SE, Richards RS, Porte AM. Functional outcome of upper limb tendon transfers performed in children with spastic hemiplegia. J Hand Surg 1993;18B:299 –303. 11. Samilson RL, Morris JM. Surgical improvement of the cerebralpalsied upper limb: electromyographic studies and results of 128 operations. J Bone Joint Surg 1964;46A:1203–1216. 12. Tanner JM, Whitehouse RH, Marubini E, Resele LF. The adolescent growth spurt of boys and girls of the Harpenden Growth Study. Ann Hum Biol 1976;3:109 –126. 13. Hägg U, Tranger J. Maturation indicators and the pubertal growth spurt. Am J Orthop 1982;82:299 –309. 14. Largo RH, Gasser T, Prader A, Stuetzle W, Huber PJ. Analysis of the adolescent growth spurt using smoothing spline functions. Ann Hum Biol 1978;5:421– 434. 15. Stevenson RD, Conaway M, Chumlea C, Rosenbaum P, Fung EB, Henderson RC, et al. Growth and health in children with moderateto-severe cerebral palsy. Pediatrics 2006;118:1010 –1018. 16. Zancolli EA, Goldner LJ, Swanson AB. Surgery of the spastic hand in cerebral palsy: report of the committee on spastic hand evaluation. J Hand Surg 1983;8A:766 –772. 17. Wenner SM, Johnson KA. Transfer of the flexor carpi ulnaris to the radial wrist extensors in cerebral palsy. J Hand Surg 1988;13A:231– 233. 18. Koman LA, Gelberman RH, Toby EB, Poehling GG. Cerebral palsy: management of the upper extremity. Clin Orthop Relat Res 1990; 253:62–74. 19. Rayan GM, Young BT. Arthrodesis of the spastic wrist. J Hand Surg 1999;24A:944 –952.
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Late Deformities Following the Transfer of the Flexor Carpi Ulnaris to the Extensor Carpi Radialis Brevis in Children With Cerebral Palsy J. Megan M. Patterson, MD, Angela A. Wang, MD, Douglas T. Hutchinson, MD
Purpose The transfer of flexor carpi ulnaris (FCU) to extensor carpi radialis brevis (ECRB) (the Green transfer) in children with cerebral palsy (CP) is a surgical option frequently used to address the typical wrist flexion deformity that is often present in these patients. We hypothesize that late deformities may occur when these transfers are performed in patients before skeletal maturity. The purpose of this investigation was to determine the frequency of these deformities and the factors that influence their development. Methods We performed 41 FCU to ECRB tendon transfers in children with CP at our institution between 1987 and 2005 and retrospectively reviewed them. A total of 24 patients with 25 transfers had a minimum 2-year follow-up and were included in the study population. We identified patients who developed a late deformity after tendon transfer. We analyzed medical records of these patients to identify factors associated with the development of a deformity. Results Of the 25 transfers, 12 developed a late deformity between 10 and 105 months postoperatively. The deformities that developed were extension deformities (8), supination deformities (one), and recurrent flexion deformities (3). Of the 12 patients with deformity, 9 required revision surgeries. Of these 12 patients, 9 who were less than 13 years of age at the time of transfer developed a late deformity, compared with 3 who were older than 13 years of age. Conclusions The FCU to ECRB tendon transfer remains a viable option to address the wrist flexion deformity seen in patients with CP. Care should be taken when performing this tendon transfer in patients less than 13 years of age because they may develop a postoperative deformity, commonly an extension deformity. We believe that these deformities develop when the patient enters a growth spurt and the transferred muscle-tendon unit does not lengthen at the same rate as the involved upper extremity. (J Hand Surg 2010;35A:1774–1778. Copyright © 2010 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Therapeutic IV. Key words Cerebral palsy, deformity, Green transfer, tendon transfer. is a nonprogressive disorder of the central nervous system that can involve the upper limb, the lower limb, or both.1–3 Although CP is a static disorder, the limb deformity often changes with growth and contractures may worsen as
C
EREBRAL PALSY (CP)
From the Department of Orthopaedics, University of North Carolina School of Medicine, Chapel Hill, NC; and the Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT. Received for publication January 8, 2010; accepted in revised form July 8, 2010. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
1774 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
the child gets older.3 Upper extremity involvement typically includes adduction and internal rotation of the shoulder, flexion of the elbow, pronation of the forearm, flexion of the wrist and fingers, swan neck deformities of the fingers, and a thumb in palm deformity. Corresponding author: J. Megan M. Patterson, MD, Department of Orthopaedics, UNC School of Medicine, 3135 Bioinformatics Bldg, CB 7055, Chapel Hill, NC 27599; e-mail: [email protected]. 0363-5023/10/35A11-0006$36.00/0 doi:10.1016/j.jhsa.2010.07.014
LATE DEFORMITIES AFTER GREEN TRANSFER FOR CP
Wrist involvement in CP has both functional and aesthetic implications. An abnormal flexion and extension arc of the wrist interferes with the digital grasp and release. A severely flexed posture of the wrist can cause difficulties with hygiene and is aesthetically unappealing to many patients and families. Transfer of flexor carpi ulnaris (FCU) to extensor carpi radialis brevis (ECRB) (the Green transfer) in children with CP has been used for a number of years to address the typical wrist flexion deformity often seen in these patients.4–9,13 Postoperative deformities after this tendon transfer have been reported to occur in 13% to 69% of patients.6 – 8 We believe that late deformities from length or tension changes occurring with growth may result when these transfers are performed in patients before skeletal maturity. The purpose of this investigation was to determine the frequency of these deformities and the factors that influence their development. MATERIALS AND METHODS After we obtained institutional review board approval, we retrospectively reviewed the charts of all patients with CP who had an FCU to ECRB tendon transfer performed at our institution between 1987 and 2005. We identified 41 transfers performed in 40 patients. We excluded from our study 16 of these transfers in 16 patients owing to inadequate follow-up. A total of 24 patients with 25 transfers had a minimum 2-year follow-up and comprised our study population. There were 11 male and 13 female patients, with an average age of 12 years at the time of their tendon transfer (range, 4 –18 y). The extent of CP involvement varied from quadriplegia in 7 patients to hemiplegia in 17 patients; 2 patients also had an athetoid component. The procedures were performed on the left upper extremity in 7 patients and the right upper extremity in 16 patients, and one patient had bilateral procedures performed. Follow-up averaged 5 years, 8 months (range, 2 y to 11 y, 3 mo). We analyzed medical records of all patients in the study group to determine factors associated with the development of late deformity after tendon transfer. We evaluated the extent of CP (quadriplegic and hemiplegic) and whether there was an athetoid component, the age at time of transfer, and the time when the deformity was noticed. We also noted any revision surgeries that were required. The surgical technique used for the FCU to ECRB tendon transfer was as described by Green and Banks.4 The transfer was tensioned between 0° and 30° of extension, although the tension at which the transfer was placed was not indicated in the surgical reports of
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9 of the 25 transfers studied. Five patients had isolated FCU to ECRB tendon transfers performed. Additional procedures were performed in 20 patients and consisted of abductor pollicis longus tenodesis (14), extensor pollicis brevis tenodesis (one), extensor pollicis longus rerouting (4), thumb intrinsic release (9), flexor digitorum superficialis and profundus lengthening (7), flexor pollicis longus lengthening (5), flexor carpi radialis lengthening (3), pronator release (4), pronator rerouting (6), palmaris longus release (1), and elbow release (3). All patients were immobilized in an above-elbow cast or splint for the first 4 to 6 weeks, after which they received a below-elbow splint for 3 months (1 mo full-time, 1 mo part-time, and 1 mo of nighttime use). The patients were immobilized with the wrist in neutral to 30° of extension and the forearm in neutral rotation while in the above-elbow splint or cast. The belowelbow splint also held the wrist in neutral to 30° of extension but did not restrict forearm rotation. Therapy was individualized for each patient but in general was not prescribed postoperatively. RESULTS From our study population, we identified 14 patients who developed a deformity in the surgical extremity after FCU to ECRB tendon transfer. Two of these deformities occurred in the immediate postoperative period, which we defined as the first 3 months after surgery, and were excluded from analysis. The remaining 12 deformities developed later in the postoperative course and were the focus of our investigation. Of the 25 transfers evaluated, 12 developed a late postoperative deformity. These patients had good positioning of their wrist until the development of their deformity, which was noted at an average of 38 months after their index procedure (range, 10 –105 mo). Eight patients developed an extension deformity, one developed a supination deformity, and 3 developed a recurrent flexion deformity. Of the 7 patients with quadriplegic CP, 5 developed a deformity, compared with only 7 of the 17 patients with hemiplegic CP. A late extension deformity occurred in one patient with an athetoid component. A total of 12 FCU to ECRB tendon transfers were performed in patients under the age of 13; of these patients, 9 developed a late postoperative deformity. In comparison, only 3 of the 12 patients who were 13 years or older at the time of their index procedure developed a late deformity (Fig. 1). At the time of surgery, the average age of patients who developed a late deformity was 10 years, 6 months, compared with
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FIGURE 1: Incidence of late deformities in patients with CP who underwent transfer of the FCU to the ECRB.
13 years, 9 months for patients who did not develop a deformity. Of the 12 patients with late deformity, 9 required revision surgeries to address problems with both function and aesthetics. Of the 8 patients who developed an extension deformity, 7 required a revision surgery to address their deformity. Revision procedures consisted of wrist arthrodesis (1 patient) and lengthening of the tendon transfer (6 patients). Of the 3 patients who developed a recurrent flexion deformity, 2 had revision surgery. One patient had a retensioning of the tendon transfer, and 1 patient had a wrist arthrodesis. Both of these revision surgeries were successful. DISCUSSION Transfer of FCU to ECRB has been used for many years to address the wrist flexion deformity commonly seen in patients with CP. Abnormal flexion and extension of the wrist interferes with the ability to use the tenodesis effect for digital grasp and release. This tendon transfer is successful because it removes the deforming force (wrist flexion and forearm pronation) and augments the desired force (wrist extension and forearm supination). Since Green’s original description in 19425 of the FCU tendon transfer in patients with CP, many authors have evaluated its efficacy and found that although it is an effective transfer to improve wrist extension, it is often associated with a postoperative hyperextension deformity.6 –11 Many factors can influence the development of a postoperative hyperextension deformity, such as FCU spasticity, the tension at which the transfer is placed, and poor postoperative compliance with immobilization and therapy. Hoffer et al. evaluated 38 patients with CP who had an FCU to ECRB tendon transfer with a minimum 8-year follow-up, and found that 13% developed a postoperative hyperextension deformity.6 Thometz and Tachdjian also reported on the long-term results of this tendon transfer in patients with
FIGURE 2: Clinical photograph of a boy 16 years, 4 months of age who underwent a right Green transfer at age 5 years, 9 months and developed a late extension deformity 8 years, 9 months postoperatively.
CP.8 They described 25 patients with a minimum 4-year follow-up and found that 9 patients developed a postoperative hyperextension deformity, although this was a functional problem only in patients who relied on wrist flexion for finger release. Wolf et al. evaluated 16 patients with CP who had an FCU to ECRB tendon transfer with a minimum 1-year follow-up, and found that postoperatively, 11 patients held the wrist in a position of extension, but that this did not interfere with function.7 In our study population, we found that late postoperative deformity occurred in 48% of patients, and the most common deformity that developed was an extension type (Fig. 2). Many studies have reported the incidence of late postoperative deformities, but a possible relationship between patients’ age at the time of surgery and the likelihood of developing a deformity has not been well studied. In our study, 82% of tendon transfers performed in patients under the age of 13 developed a late postoperative deformity, whereas only 25% of patients who were 13 years or older at the time of the index procedure had a similar outcome. The late deformities noted in our study developed an average of 38 months postoperatively (range, 10 –105 mo), often occurring after the family noted the patient undergoing a period of rapid growth. The adolescent growth spurt in normal children usually occurs between the ages of 10 and 14 in girls, and between the ages of 12 and 16 in boys.12–14 Growth studies in children with CP have shown that although their adolescent growth spurts are blunted, these patients have growth curves that are similar in
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shape to unaffected children.15 Current studies in the literature that describe late postoperative hyperextension deformities evaluated patients who ranged in age from 4 to 23 years. However, these studies do not specify the ages of patients who developed a hyperextension deformity and when these deformities occurred. We believe that this is a critical piece of information because we hypothesize that these late deformities occur when patients who underwent an FCU to ECRB tendon transfer at a young age enter the adolescent growth spurt, and the transferred musculotendinous unit does not grow and stretch at the same rate as the skeleton. We believe that scar tissue at the site of the transfer does not have the ability to stretch and adapt with rapid growth and thus contributes to the worsening deformity that is seen. In Green and Banks’ original description, the authors recommended that the transfer be performed when the patient is old enough to participate in therapy.4 Since then, different recommendations have been made regarding the optimal time for tendon transfer, ranging from as early as 4 years of age to as late as 12 years of age.1–3,9,16 It is recommended that surgery be delayed until motor patterns are established, the deformity is static, and patients are able to participate in postoperative therapy.2– 4 Concern has been raised that if surgery is delayed until the patient is older, bone deformity, muscle fibrosis, and joint contractures may occur.2,16 In addition, patients may have accepted the functional and cosmetic deformity and may no longer be interested in surgery.16 Beach et al. evaluated 40 patients with CP who underwent an FCU to ECRB tendon transfer with an average follow-up of 5 years, 3 months, and found that the best results were seen in patients who had the transfer between the ages of 7 and 12 years.9 Although patients older than 12 years of age showed functional improvement, it was not as great as the improvements seen in the group of patients who were less than 7 years of age, or those who were 7 to 12 years of age (71% improvement vs 83% and 86%, respectively). In that study, there was one postoperative supination deformity and one postoperative hyperextension deformity, both of which occurred in patients younger than 10 years of age. In our study, we found that patients under the age of 13 at the time of tendon transfer were much more likely to develop a postoperative deformity than patients who had transfers when they were older than 13 years of age (82% vs 25%). We agree that performing the tendon transfer when the patient is young may be indicated to improve the function and aesthetic appearance of the limb; however, it may place patients at a higher risk of postoperative deformity. We recommend
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that if this tendon transfer is performed before the age of 13, patients should have close follow-up throughout their growth spurt to monitor for the development of deformity. This is especially true for patients with spastic quadriplegia, because we found that these patients were more likely to develop a late postoperative deformity compared with patients with hemiplegic CP. All transfers in our study for which data were available were tensioned between neutral and 30° of extension. Green and Banks’ original description recommended that the transfer be placed such that the wrist is held in 45° of extension and full supination; in that series, the authors reported no patients developed an extension posture.4 Most other authors recommended that the transfer be tensioned between neutral and 20° of extension.3,6,9,17 We agree with these authors and feel that the FCU to ECRB tendon transfer should be tensioned in no more than 30° of extension because postoperative hyperextension deformities have been reported in patients whose transfers were tensioned in maximum extension.8,9 A challenge of any study that evaluates patients with CP is that the extent of deformity and limb involvement varies, as do the surgeries performed, which makes it difficult to compare patients within a study as well as between studies. The variability in both our patient population as well as the secondary procedures performed is a limitation of this study. We chose to include all patients with CP who had an FCU to ECRB tendon transfer in our study population regardless of the extent of disease involvement or whether the patients had additional procedures performed on the upper extremity because we believe this gives a more accurate representation of the true spectrum of the disease. An additional limitation of this study is possible follow-up bias. Patients who developed a postoperative deformity and who were unsatisfied with their result may have been more likely to return for further care. It is also possible that those patients who had surgery at a younger age may have had a more severe condition that may have made them more likely to develop a postoperative deformity. We acknowledge that there are likely multiple factors that contribute to the development of postoperative deformities after the transfer of FCU to ECRB, including failure of the transfer, overtensioning of the transfer, muscle spasticity, and dystonia. We hypothesize that age at the time of transfer and the patient’s growth likely have an important role given the high rate of late deformities seen in our younger patients. Further research evaluating the long-term outcomes of young children after tendon transfers is needed to help deter-
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mine the true risk of developing a late deformity in children with and without CP. Based on our findings, we believe that although FCU to ECRB tendon transfer remains a viable option to address the wrist flexion deformity commonly seen in patients with CP, its timing remains a balancing act. Performing this tendon transfer in skeletally immature patients may result in deformity as a result of muscle imbalance; nevertheless, it remains a better option for most patients than wrist arthrodesis or chondrodesis.2,18,19 Care should be taken when performing the procedure in patients under the age of 13 because we found that as much as 82% of these patients develop a late postoperative deformity, most commonly an extension deformity. Family education regarding the risk of late deformity should be part of the preoperative discussion, and these patients should be observed at regular intervals postoperatively until they reach skeletal maturity. REFERENCES 1. Skoff H, Woodbury DF. Current concepts review: management of the upper extremity in cerebral palsy. J Bone Joint Surg 1985;67A: 500 –503. 2. Mital MA, Sakellarides HT. Surgery of the upper extremity in the retarded individual with spastic cerebral palsy. Orthop Clin North Am 1981;12:127–141. 3. Goldner JL. Surgical reconstruction of the upper extremity in cerebral palsy. Hand Clin 1988;4:223–265. 4. Green WT, Banks HH. Flexor carpi ulnaris transplant and its use in cerebral palsy. J Bone Joint Surg 1962;44A:1343–1352. 5. Green WT. Tendon transplantation of the flexor carpi ulnaris for pronation-flexion deformity of the wrist. Surg Gynecol Obstet 1942; 75:337–342
6. Hoffer MM, Lehman M, Mitani M. Long-term follow-up on tendon transfers to the extensors of the wrist and fingers in patients with cerebral palsy. J Hand Surg 1986;11A:836 – 840. 7. Wolf TM, Clinkscales CM, Hamlin C. Flexor carpi ulnaris tendon transfers in cerebral palsy. J Hand Surg 1998;23B:340 –343. 8. Thometz JG, Tachdjian M. Long-term follow-up of the flexor carpi ulnaris transfer in spastic hemiplegic children. J Pediatr Orthop 1988;8:407– 412. 9. Beach WR, Strecker WB, Coe J, Manske PR, Schoenecker RL, Dailey L. Use of the Green transfer in treatment of patients with spastic cerebral palsy: 17 year experience. J Pediatr Orthop 1991; 11:731–736. 10. Roth JH, O’Grady SE, Richards RS, Porte AM. Functional outcome of upper limb tendon transfers performed in children with spastic hemiplegia. J Hand Surg 1993;18B:299 –303. 11. Samilson RL, Morris JM. Surgical improvement of the cerebralpalsied upper limb: electromyographic studies and results of 128 operations. J Bone Joint Surg 1964;46A:1203–1216. 12. Tanner JM, Whitehouse RH, Marubini E, Resele LF. The adolescent growth spurt of boys and girls of the Harpenden Growth Study. Ann Hum Biol 1976;3:109 –126. 13. Hägg U, Tranger J. Maturation indicators and the pubertal growth spurt. Am J Orthop 1982;82:299 –309. 14. Largo RH, Gasser T, Prader A, Stuetzle W, Huber PJ. Analysis of the adolescent growth spurt using smoothing spline functions. Ann Hum Biol 1978;5:421– 434. 15. Stevenson RD, Conaway M, Chumlea C, Rosenbaum P, Fung EB, Henderson RC, et al. Growth and health in children with moderateto-severe cerebral palsy. Pediatrics 2006;118:1010 –1018. 16. Zancolli EA, Goldner LJ, Swanson AB. Surgery of the spastic hand in cerebral palsy: report of the committee on spastic hand evaluation. J Hand Surg 1983;8A:766 –772. 17. Wenner SM, Johnson KA. Transfer of the flexor carpi ulnaris to the radial wrist extensors in cerebral palsy. J Hand Surg 1988;13A:231– 233. 18. Koman LA, Gelberman RH, Toby EB, Poehling GG. Cerebral palsy: management of the upper extremity. Clin Orthop Relat Res 1990; 253:62–74. 19. Rayan GM, Young BT. Arthrodesis of the spastic wrist. J Hand Surg 1999;24A:944 –952.
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