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Surgical management of wrist and finger deformity
Hand Clin 19 (2003) 657–665
Surgical management of wrist and finger deformity Ann E. Van Heest, MD University of Minnesota, Department of Orthopedic Surgery, Hand Surgery Section, Gillette Children’s Specialtycare, Shriner’s Hospital–Twin Cities Unit, 2450 Riverside Avenue South, R200, Minneapolis, MN 55454, USA
The major goal in surgical reconstruction of the wrist and fingers is to restore muscle force balance across the joints to improve function and provide a less ‘‘palsied’’ appearance. Treatment is aimed at altering the imbalance between the spastic flexor-pronator muscle group and the paretic extensor–supinator group. Additionally, surgical treatment targets treating joint imbalance to prevent fixed deformity. The surgeon is required to assess carefully the type of deformity and its treatment at each upper extremity joint separately and then combine them to organize a comprehensive surgical reconstructive plan. Adequate shoulder, elbow, and forearm function is necessary for the patient to be able to position the limb in space appropriately; adequate wrist, finger, and thumb function is necessary for appropriate grasp, pinch, and release. Because the extrinsic finger muscles are biarticular (ie, they cross the wrist and finger joints), the position of the wrist significantly affects the position and function of the finger extrinsic muscles. The wrist and fingers thus commonly are assessed together. Evaluation of wrist and finger deformity most commonly has followed Zancolli’s classification [1] as shown in Box 1. A normal pattern of grasp and release is necessary for hand function. When the wrist is in substantial flexion, grasp strength is decreased as the finger flexors become relatively shortened. If the wrist is corrected to neutral, manually or in a splint, finger flexion strength increases, but often there is a loss of the ability to release. The
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problem of inadequate release is as much of a functional concern as inadequate grasp strength. Finger and wrist deformity must be addressed to provide overall grasp and release function.
Wrist treatment options The most common deformity of the wrist is flexion, usually with ulnar deviation. This is probably the most functionally disabling deformity of the upper limb in cerebral palsy, as it significantly interferes with grasp and release function. The wrist flexion deformity is often the most obvious physical manifestation of the patient’s cerebral palsy and correction of the ‘‘palsy’’ position helps with the patient’s self esteem. Several different surgical options exist; the choice depends on the degree of deformity and the extent of volitional control of each muscle involved. Application of the following surgical principles is a necessary part of the art of designing a successful reconstructive plan: release or lengthening the deforming spastic muscles (flexor carpi ulnaris [FCU], flexor carpi radialis [FCR]), transfer of tendons to augment the weak antagonist muscles (extensor carpi radialis longus/brevis [ECRL/B]), and stabilization of the joint only for the severe, fixed, nonfunctioning wrist (wrist fusion). Surgical treatment options for correction of wrist and finger deformities are outlined in Table 1. Release/lengthening of spastic flexor muscles If the wrist flexion deformity is mild and wrist extensor control exists, weakening the wrist flexors through surgical fractional lengthening or with a series of botulinum injections [2] in
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Box 1. Zancolli classification [1] Group Group Group Group Group
1. Active finger extension with less than 20 of wrist flexion 2. Active finger extension with more than 20 of wrist flexion 2a. Active wrist extension with the fingers flexed 2b. No active wrist extension with the fingers flexed 3. Wrist and finger extension absent even with full wrist flexion
combination with serial casting, splinting, or stretching may provide sufficiently increased wrist flexor muscle lengthening to decrease overall wrist flexion posturing. If the mild wrist flexion deformity exhibits concomitant wrist ulnar deviation, the FCU only would be lengthened. If a more severe wrist flexion deformity exhibits concomitant finger flexion and pronator spasticity, the entire flexor pronator mass can be lengthened using a flexor pronator slide [3,4]. Tendon transfers to augment weak or absent wrist extensors If the wrist flexor deformity is more severe and wrist extensors are not functional, tendon transfer surgery to augment wrist extension may be necessary. Muscles that can be transferred into wrist extensors include the brachioradialis (BR), the extensor carpi ulnaris (ECU), or the FCU. Using the BR or the ECU as the donor tendon has the advantage of leaving both flexor tendons intact, thus avoiding overcorrection, but has the disadvantage of not achieving balance unless the wrist flexors are lengthened if their spasticity is significant. Using the ECU tendon has the advantage of correction of the ulnar deviation
deformity, although this may require FCU lengthening concomitantly, but has the disadvantage of not providing significantly more wrist extension force than is already present. Using the FCU tendon has the advantage of removing its force as a spastic wrist flexor/ulnar deviator while transferring its forces into wrist extension, but has the disadvantage of overcorrection if the deformity is not severe or if the transfer is sutured too tightly, particularly in the younger child. FCU to ECRB tendon transfer is demonstrated in Fig. 1. The FCU to radial wrist extensor tendon transfer was first described by Green [5]. Many studies have reported the functional improvement seen by improved wrist function after the Green tendon transfer [6–9]. Wolf et al [10] reported 16 children treated with FCU to ECRL tendon transfer with an average follow-up of 4 years (range, 1–9 years). Average final resting position was 9 of extension with 14 of 16 patients reporting improved function and 16 of 16 patients reporting improved cosmesis. El-Said [11] has described the use of a selective release of the flexor origin concomitantly with transfer of the FCU in 35 patients with an average follow-up of 4 years. The appearance of the hand and forearm improved in all patients; all gained improved mobility of the
Table 1 Surgical treatment options
Tendon Release/Lengthenings Tendon transfers
Joint stabilization
Wrist flexion ulnar deviation
Finger deformities
Flexor pronator slide FCR lengthening FCU lengthening FCU to ECRB FCU to EDC BR to ECRB ECU to ECRB Wrist fusion Proximal row carpectomy
Flexor pronator slide FDS lengthening FDP lengthening Superficialis to profundus transfer Lateral band rerouting (swan neck)
PIP fusion DIP fusion
BR, brachioradialis; DIP, distal interphalangeal joint; ECRB, extensor carpi radialis brevis; ECU, extensor carpi ulnaris; FCR, flexor carpi radialis; FCU, flexor carpi ulnaris; PIP, proximal interphalangeal joint. From Zancolli EA. Structural and dynamic bases of hand surgery. 2nd edition. Philadelphia: JB Lippincott; 1979; with permission.
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forearm, wrist, and hand. Long-term follow-up of 25 patients [7] treated at a mean age of 8 years with a mean follow-up of 8 years, 7 months reported a final arc of motion of 44 of wrist extension and 19 of wrist flexion. Two patients required revision for overcorrection into a wrist extension/supination deformity. They recommended FCU to radial wrist extensor tendon transfer for patients who lack active wrist extension but who have good digital extension with the wrist passively extended above neutral. Newer concepts in determining optimal intraoperative tension have been described recently. Lieber et al [12] reported the use of intraoperative sarcomere length measurements and its relationship to tensioning of tendons during tendon transfer surgery. Because it is not possible to predict the relationship between passive tension and muscle length, these investigators have advocated the experimental use of an intraoperative device that allows measurement of sarcomere length as a basis for tensioning tendon transfers. Although this new measurement modality has been shown to be significant in an experimental model [13–16], it has not been tested specifically in the clinical setting. Whether transfers set at optimal sarcomere length are associated with improved functional outcomes remains to be studied. Another concern regarding the FCU transfer into the ECRB/L is the optimal vector for placement (ie, the extent to which the FCU origin should be released and the angle at which the tendon is inset). In the original description, Green [5] recommended the FCU transfer be into the ‘‘tendon of the ECRB to give more central action in dorsiflexion, whereas the tendon of the ECRL, which is more radial in position, gives a better direction of pull for supinator action and gives better correction of the ulnar deviation.’’ Cadaveric studies subsequently have shown that insertion into the ECRB versus the ECRL did not change the supination effect of the transfer significantly. Rather, freeing the muscle up to the proximal one third of the forearm gave it a less acute angle of insertion and increased its supination effect [17]. The FCR should not be used as a transfer for wrist extension, as it would provide a secondary pronation vector that would exacerbate the patient’s pronation deformity. In all cases of transfer into the wrist extensors, the finger function must be assessed preoperatively with the wrist in neutral, the desired postoperative position. If the finger flexors are too tight when the wrist is brought into neutral,
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a finger flexor lengthening will be necessary as part of the procedure. This is a common combination of procedures for many surgeons [18,19]. If the patient does not have finger extensor control to allow for release of grasped objects, a transfer into the finger extensors (EDC) may be indicated. Other series have found that transfer of the FCU into the EDC is rarely necessary [8,20], as balancing the wrist may be the key component to unmasking finger function.
Wrist stabilization If the patient has a severe wrist joint contracture limiting functional use of the hand (even as a paperweight), consideration should be given to a proximal row carpectomy (PRC) to shorten the skeleton or a wrist fusion to hold the wrist in a fixed, more functional position. The PRC is used in combination with tendon transfers and releases in patients in which passive extension of the wrist does not reach the neutral position. Passive mobility of the wrist is a necessary prerequisite to tendon transfer surgery, which aims to improve active mobility. Tonkin and Gschwind describe treatment of 34 patients with wrist and finger flexion deformities; four patients were treated with a combination of PRC, FCR, or FCU to ECRB, flexor aponeurotic release, and thumb and pronation procedures. The postoperative extension was 8 and all regained some ability to extend the fingers. Wrist fusion predictably maintains the wrist in a fixed position and usually is indicated for improved cosmesis and use of the hand as a paperweight in the skeletally mature individual [21]. The proximal carpal row can be removed as part of the wrist fusion to facilitate positioning of the wrist into slight extension [22], as shown in Fig. 2. Hargreaves et al [23] reported 11 wrist fusions in 10 patients treated at an average age of 18.8 years (range, 13–35). Concomitant PRC was performed in eight wrists and soft tissue releases in three. Improved function from preoperative ‘‘none’’ or ‘‘assist’’ levels was improved postoperatively to ‘‘assist’’ to ‘‘simple’’ function. Fusion was achieved in all cases, using plate fixation in nine patients and crossed K-wires (because of open physes) in two patients. Wrist fusion is contraindicated in the individual who uses wrist flexion tenodesis for release function, as this function would be lost if the wrist were to be fixed in a single position. It may be particularly beneficial when an athetoid component dominates.
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Finger surgery The most common finger deformities are the spastic flexion deformity and the swan neck deformity. Spastic flexion deformities causing a clenched fist need to be addressed in conjunction with the wrist flexion deformity. The flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) muscles are biarticular, crossing the wrist and finger joints. They thus need to be lengthened in concert with the wrist flexion deformity correction as part of a flexor pronator slide or with selective fascial lengthenings. The flexor pronator slide was described originally by Page [24] in 1923, reporting on six patients of whom two had cerebral palsy. Several subsequent reports [3,4] discuss the role of the flexor pronator slide in decreasing spastic forces in the wrist and finger flexors simultaneously and how this may unmask wrist and finger extension. For the more severe clenched fist deformity, cosmesis and hygiene may be the greater concern. Superficialis to profundus (STP) transfer is used to treat severe spastic flexion contractures of the hand. It is the treatment of choice in the nonfunctional hand with a spastic clenched fist deformity. Palma et al [25] have performed more than 75 STP transfers to relieve pain, improve hygiene, and ease daily activities for patients and caregivers and found the procedure to be effective, predictable, and safe. It was combined commonly with a wrist arthrodesis, carpal tunnel release, and ulnar motor neurectomy. Braun et al [26] reported that the STP operation ‘‘attained the limited goals set for this initial group of patients with severe flexion problems, who had little hope for restored function of individual flexor tendons. In twenty one patients, the resting position of the hand was improved.’’ They warn that release of the spastic
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extrinsic flexors may unmask intrinsic spasticity that may need to be addressed secondarily. In addition to release of the spastic flexors of the fingers, the question may arise as to whether tendon transfers may be necessary to augment finger extension. Smith [27] recommends tendon transfers for finger extension only after release procedures are completed to the wrist and fingers. Often it may take 6 months or longer until the tone of the digital extensors returns after the persistent stretch of the extensors has been released by lengthening of the flexors. Hoffer et al [28] reported 38 patients treated with tendon transfers to improve extension of the wrist and fingers. Twenty patients were treated with transfer of the FCU to the ECRB and 18 patients were treated with transfer of the FCU into the EDC. Of these 18 patients, 16 showed significant functional improvement. He recommended that the FCU be transferred to the EDC in patients with the apparent inability to release their hands (ie, cannot extend their digits with their wrist extended). Other series have found that transfer of the FCU into the EDC is rarely necessary [8,20], as balancing the wrist may be the key component to unmasking finger function. After clenched fist deformity, the next most common deformity seen is the swan neck. The pathophysiology of this deformity in cerebral palsy is the dynamic imbalance of the muscles acting on the proximal interphalangeal (PIP) joint, causing PIP joint hyperextension with distal interphalangeal joint flexion (Fig. 3). In cerebral palsy, swan neck deformities are caused by intrinsic muscle spasticity, often augmented by overactivity of the extrinsic finger extensors. Spasticity of the intrinsic muscles causes overpull of the lateral bands, accentuating PIP joint
b Fig. 1. (A) Preoperative view of dynamic wrist flexion deformity resulting in a poor active assist hand with significant disability for grasp and pinch functions. This 16-year-old girl had normal intelligence, moderate sensibility (10 of 12 objects stereognosis function), and high motivation. No active wrist extension was present preoperatively, with good control of active finger extension. She showed good preoperative selective control of the FCU despite its spasticity. (B) Through a longitudinal incision extending the distal two thirds of the forearm along the ulnar border, the FCU was harvested from its insertion. (C) A curvilinear incision over the radial wrist extensors was used for weaving the FCU into the ECRB just proximal to the extensor retinaculum. The same incision was used as part of the EPL rerouting. A separate incision was used in the antecubital fossa for a biceps lengthening and brachialis fascial release. (D) The FCU is harvested off its pisiform insertion and freed from its fascial attachments. (E) The FCU tendon is transferred dorsally, removing it as a wrist flexor and providing its force as an active wrist extensor. The tendon is tensioned so that the wrist lies antigravity at rest in a neutral position. (F) Following the procedure, active wrist extension was achieved for effective grasp. Finger function was good for release. Good active assist function was achieved.
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Fig. 2. (A) Preoperative radiographs of a fixed flexion wrist contracture in a skeletally mature 17-year-old boy. Note the finger extension present preoperatively, indicating minimal finger flexor contractures. (B) Proximal row carpectomy combined with wrist fusion by plating was used. Adequate finger excursion was present so that concomitant finger flexor lengthening was not necessary in this case.
extension. With chronic intrinsic spasticity, overpull of the lateral band causes incompetence of the transverse retinacular ligament, stretching of the PIP joint volar plate, and resultant dorsal subluxation of the lateral bands. Additionally, some patients with cerebral palsy have better volitional control of their extrinsic finger extensors than they have of their wrist extensors. Patients thus attempt to extend their wrists through activation of their extrinsic finger extensors, causing metacarpophalangeal (MCP) joint extension and exacerbating PIP joint hyperextension (swan-necking).
Finally, excessive lengthening or surgical release of the FDS, such as used in the STP transfer, often unmasks intrinsic spasticity, resulting in significant swan neck deformities, as the flexion forces on the PIP joint are diminished iatrogenically. The indication for surgical correction is locking swan neck deformities (usually greater than 40 ) that are not responsive to splinting and that interfere with function. For the patient with significant wrist flexion deformities and only mild swan-necking, surgical correction of wrist position alone may be
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Fig. 3. (A) Pathophysiology of swan neck deformity in cerebral palsy. In cerebral palsy, the intrinsic muscles are spastic. The extrinsic finger extensors are overactive in their attempt to augment wrist extension when a wrist flexion deformity exists. Intrinsic spasticity combined with extrinsic overpull causes PIP joint hyperextension with resultant incompetency of the transverse retinacular ligament and volar plate. PIP joint hyperextension concentrates the extension forces at the PIP joint with slackening of the terminal tendon allowing DIP joint flexion. (B) This patient exhibits swan neck deformities that lock in extension and inhibit his abilities to grasp his walker.
adequate for treatment. For the patient with severe swan necking (>40 ), rebalancing of the muscle forces at the PIP joint is necessary. Surgical options include lateral band rerouting [29,30], lateral band tenodesis [31], superficialis tenodesis [32], spiral oblique ligament reconstruction [33], intrinsic muscle slide [34], or a resection of the ulnar nerve motor branch in Guyon’s canal [35]. The author’s preferred method is the lateral band rerouting procedure shown in Fig. 4, because it requires less extensive dissection and rebalances the intrinsic and extrinsic tendon deforming forces.
Summary The surgical results of upper extremity intervention have been shown to improve hand function from paperweight/passive assist function to active assist function [20]. Although children with cerebral palsy commonly have a sensibility
deficiency in conjunction with their motor deficiency [36,37], several recent studies have disproved the previous doctrine that hand surgery should not be performed on children with sensibility deficiencies. The author’s report [20] of 134 children treated surgically showed that preoperatively 50% had impaired two-point discrimination and 75% had impaired stereognosis; impaired sensibility had no adverse effect on surgical results. Eliasson et al [18] reported on 32 children treated surgically with tendon transfers and muscle releases. Impaired sensibility before the surgery did not influence the outcome. In fact, Dahlin et al [38] reported 36 patients treated operatively and followed for 18 months, finding an improvement in stereognosis function associated with the improvement in their motor function, presumably because of improved functional use. Children with cerebral palsy can improve their motor function and perhaps also their sensibility function with appropriately planned and executed
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Fig. 4. (A) The extensor mechanism is incised longitudinally in the interval between the central slip and the lateral band to allow the volar mobilization of the lateral band to the level of the volar plate. The A3 pulley is opened and sutured closely around the lateral band, anchoring the lateral band volar to the axis of the PIP joint. The rerouting is tensioned so that the PIP has light resistance to extension past 30 of flexion and does not extend past 5 of flexion. (B) Following lateral band rerouting, this patient can actively extend his fingers without locking and can grasp his walker effectively.
tendon release and transfer surgery. Balance of the wrist and fingers is the key element in improvement of upper limb function.
[4]
References
[5]
[1] Zancolli EA. Structural and dynamic bases of hand surgery. 2nd edition. Philadelphia: JB Lippincott; 1979. [2] Van Heest A. Applications of botulinum toxin in orthopedics and upper extremity surgery. Tech Hand Upper Extrem Surg 1997;1(1):27–34. [3] Inglis AE, Cooper W. Release of the flexor-pronator origin for flexion deformities of the hand and
[6]
[7]
wrist in spastic paralysis. A study of eighteen cases. J Bone Joint Surg 1966;48A(5):847–57. White WF. Flexor muscle slide in the spastic hand: the Max Page operation. J Bone Joint Surg 1972; 54B(3):453–9. Green WT. Tendon transplantation of the flexor carpi ulnaris for pronation-flexion deformity of the wrist. Surg Gynecol Obstet 1942;75:337–42. 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(6):836–40. Thometz JG, Tachdjian M. Long-term follow-up of the flexor carpi ulnaris transfer in spastic hemiplegic children. J Pediatr Orthop 1988;8(4):407–12.
A.E. Van Heest / Hand Clin 19 (2003) 657–665 [8] Tonkin M, Gshwind C. Surgery for cerebral palsy: part 2. Flexion deformity of the wrist and fingers. J Hand Surg 1992;17B(4):396–400. [9] Wenner SM, Johnson KA. Transfer of the flexor carpi ulnaris to the radial wrist extensors in cerebral palsy. J Hand Surg 1988;13A(2):231–3. [10] Wolf TM, Clinkscales CM, Hamlin C. Flexor carpi ulnaris tendon transfers in cerebral palsy. J Hand Surg 1998;23B(3):340–3. [11] El-Said NS. Selective release of the flexor origin with transfer of flexor carpi ulnaris in cerebral palsy. J Bone Joint Surg 2001;83B(2):259–62. [12] Lieber RL, Friden J. Intraoperative measurement and biomechanical modeling of the flexor carpi ulnaris-to-extensor carpi radialis longus tendon transfer. J Biomech Eng 1997;119(4):386–91. [13] Burkholder TJ, Lieber RL. Sarcomere length operating range of vertebrate muscles during movement. J Exp Biol 2001;204(Pt 9):1529–36. [14] Friden J, Lieber RL. Spastic muscle cells are shorter and stiffer than normal cells [comment]. Muscle Nerve 2003;27(2):157–64. [15] Friden J, Lieber RL. Tendon transfer surgery: clinical implications of experimental studies. Clin Orthop 2002;403(Suppl):S163–70. [16] Friden J, Ponten E, Lieber RL. Effect of muscle tension during tendon transfer on sarcomerogenesis in a rabbit model. J Hand Surg 2000;25A(1):138–43. [17] Van Heest AE, Murthy NS, Sathy MR, Wentorf FA. The supination effect of tendon transfer of the flexor carpi ulnaris to the extensor carpi radialis brevis or longus: a cadaveric study. J Hand Surg 1999;24A(5):1091–6. [18] Eliasson AC, Ekholm C, Carlstedt T. Hand function in children with cerebral palsy after upper-limb tendon transfer and muscle release [comment]. Dev Med Child Neurol 1998;40(9): 612–21. [19] Wright T. Tendon transfer for wrist flexion deformity in cerebral palsy. Atlas Hand Clin 2002; 7:133–51. [20] Van Heest AE, House JH, Cariello C. Upper extremity surgical treatment of cerebral palsy. J Hand Surg 1999;24A(2):323–30. [21] Hoffer MM, Zeitzew S. Wrist fusion in cerebral palsy. J Hand Surg 1988;13A(5):667–70. [22] Louis DS, Hankin FM, Bowers WH. Capitateradius arthrodesis: an alternative method of radiocarpal arthrodesis. J Hand Surg 1984;9A(3):365–9.
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[23] Hargreaves DG, Warwick DJ, Tonkin MA. Changes in hand function following wrist arthrodesis in cerebral palsy. J Hand Surg 2000;25B(2):193–4. [24] Page CM. An operation for the relief of flexion contracture in the forearm. J Bone Joint Surg 1923; 5A:233–4. [25] Palma D, Fuller D, Keenan MA. Superficialis to profundus tendon transfer. Atlas Hand Clin 2002; 7:153–62. [26] Braun RM, Vise GT, Roper B. Preliminary experience with superficialis-to-profundus tendon transfer in the hemiplegic upper extremity. J Bone Joint Surg 1974;56(3):466–72. [27] Smith RJ. Tendon transfers of the hand and forearm. Boston: Little, Brown & Company; 1987. [28] 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(6):836–40. [29] Tonkin MA, Hughes J, Smith KL. Lateral band translocation for swan-neck deformity. J Hand Surg 1992;17A(2):260–7. [30] Van Heest A. Lateral band re-routing in the treatment of swan neck deformities due to cerebral palsy. Tech Hand Upper Extrem Surg 1997;1: 189–94. [31] Littler JW. The finger extensor mechanism. Surg Clin N Am 1967;47:415–32. [32] Swanson AB. Surgery of the hand in cerebral palsy and the swan-neck deformity. J Bone Joint Surg 1960;42A(6):951–64. [33] Thompson JS, Littler JW, Upton J. The spiral oblique retinacular ligament (SORL). J Hand Surg 1978;3A(5):482–7. [34] Zancolli EA, Zancolli ER Jr. Surgical management of the hemiplegic spastic hand in cerebral palsy. Surg Clin N Am 1981;61(2):395–406. [35] Manske PR. Cerebral palsy of the upper extremity. Hand Clin 1990;6(4):697–709. [36] Van Heest AE, House J, Putnam M. Sensibility deficiencies in the hands of children with spastic hemiplegia. J Hand Surg 1993;18A(2):278–81. [37] Waters PM, Van Heest A. Spastic hemiplegia of the upper extremity in children. Hand Clin 1998;14(1): 119–34. [38] Dahlin LB, Komoto-Tufvesson Y, Salgeback S. Surgery of the spastic hand in cerebral palsy. Improvement in stereognosis and hand function after surgery. J Hand Surg 1998;23B(3):334–9.
Surgical management of wrist and finger deformity Ann E. Van Heest, MD University of Minnesota, Department of Orthopedic Surgery, Hand Surgery Section, Gillette Children’s Specialtycare, Shriner’s Hospital–Twin Cities Unit, 2450 Riverside Avenue South, R200, Minneapolis, MN 55454, USA
The major goal in surgical reconstruction of the wrist and fingers is to restore muscle force balance across the joints to improve function and provide a less ‘‘palsied’’ appearance. Treatment is aimed at altering the imbalance between the spastic flexor-pronator muscle group and the paretic extensor–supinator group. Additionally, surgical treatment targets treating joint imbalance to prevent fixed deformity. The surgeon is required to assess carefully the type of deformity and its treatment at each upper extremity joint separately and then combine them to organize a comprehensive surgical reconstructive plan. Adequate shoulder, elbow, and forearm function is necessary for the patient to be able to position the limb in space appropriately; adequate wrist, finger, and thumb function is necessary for appropriate grasp, pinch, and release. Because the extrinsic finger muscles are biarticular (ie, they cross the wrist and finger joints), the position of the wrist significantly affects the position and function of the finger extrinsic muscles. The wrist and fingers thus commonly are assessed together. Evaluation of wrist and finger deformity most commonly has followed Zancolli’s classification [1] as shown in Box 1. A normal pattern of grasp and release is necessary for hand function. When the wrist is in substantial flexion, grasp strength is decreased as the finger flexors become relatively shortened. If the wrist is corrected to neutral, manually or in a splint, finger flexion strength increases, but often there is a loss of the ability to release. The
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problem of inadequate release is as much of a functional concern as inadequate grasp strength. Finger and wrist deformity must be addressed to provide overall grasp and release function.
Wrist treatment options The most common deformity of the wrist is flexion, usually with ulnar deviation. This is probably the most functionally disabling deformity of the upper limb in cerebral palsy, as it significantly interferes with grasp and release function. The wrist flexion deformity is often the most obvious physical manifestation of the patient’s cerebral palsy and correction of the ‘‘palsy’’ position helps with the patient’s self esteem. Several different surgical options exist; the choice depends on the degree of deformity and the extent of volitional control of each muscle involved. Application of the following surgical principles is a necessary part of the art of designing a successful reconstructive plan: release or lengthening the deforming spastic muscles (flexor carpi ulnaris [FCU], flexor carpi radialis [FCR]), transfer of tendons to augment the weak antagonist muscles (extensor carpi radialis longus/brevis [ECRL/B]), and stabilization of the joint only for the severe, fixed, nonfunctioning wrist (wrist fusion). Surgical treatment options for correction of wrist and finger deformities are outlined in Table 1. Release/lengthening of spastic flexor muscles If the wrist flexion deformity is mild and wrist extensor control exists, weakening the wrist flexors through surgical fractional lengthening or with a series of botulinum injections [2] in
0749-0712/03/$ - see front matter Ó 2003 Elsevier Inc. All rights reserved. doi:10.1016/S0749-0712(03)00076-3
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Box 1. Zancolli classification [1] Group Group Group Group Group
1. Active finger extension with less than 20 of wrist flexion 2. Active finger extension with more than 20 of wrist flexion 2a. Active wrist extension with the fingers flexed 2b. No active wrist extension with the fingers flexed 3. Wrist and finger extension absent even with full wrist flexion
combination with serial casting, splinting, or stretching may provide sufficiently increased wrist flexor muscle lengthening to decrease overall wrist flexion posturing. If the mild wrist flexion deformity exhibits concomitant wrist ulnar deviation, the FCU only would be lengthened. If a more severe wrist flexion deformity exhibits concomitant finger flexion and pronator spasticity, the entire flexor pronator mass can be lengthened using a flexor pronator slide [3,4]. Tendon transfers to augment weak or absent wrist extensors If the wrist flexor deformity is more severe and wrist extensors are not functional, tendon transfer surgery to augment wrist extension may be necessary. Muscles that can be transferred into wrist extensors include the brachioradialis (BR), the extensor carpi ulnaris (ECU), or the FCU. Using the BR or the ECU as the donor tendon has the advantage of leaving both flexor tendons intact, thus avoiding overcorrection, but has the disadvantage of not achieving balance unless the wrist flexors are lengthened if their spasticity is significant. Using the ECU tendon has the advantage of correction of the ulnar deviation
deformity, although this may require FCU lengthening concomitantly, but has the disadvantage of not providing significantly more wrist extension force than is already present. Using the FCU tendon has the advantage of removing its force as a spastic wrist flexor/ulnar deviator while transferring its forces into wrist extension, but has the disadvantage of overcorrection if the deformity is not severe or if the transfer is sutured too tightly, particularly in the younger child. FCU to ECRB tendon transfer is demonstrated in Fig. 1. The FCU to radial wrist extensor tendon transfer was first described by Green [5]. Many studies have reported the functional improvement seen by improved wrist function after the Green tendon transfer [6–9]. Wolf et al [10] reported 16 children treated with FCU to ECRL tendon transfer with an average follow-up of 4 years (range, 1–9 years). Average final resting position was 9 of extension with 14 of 16 patients reporting improved function and 16 of 16 patients reporting improved cosmesis. El-Said [11] has described the use of a selective release of the flexor origin concomitantly with transfer of the FCU in 35 patients with an average follow-up of 4 years. The appearance of the hand and forearm improved in all patients; all gained improved mobility of the
Table 1 Surgical treatment options
Tendon Release/Lengthenings Tendon transfers
Joint stabilization
Wrist flexion ulnar deviation
Finger deformities
Flexor pronator slide FCR lengthening FCU lengthening FCU to ECRB FCU to EDC BR to ECRB ECU to ECRB Wrist fusion Proximal row carpectomy
Flexor pronator slide FDS lengthening FDP lengthening Superficialis to profundus transfer Lateral band rerouting (swan neck)
PIP fusion DIP fusion
BR, brachioradialis; DIP, distal interphalangeal joint; ECRB, extensor carpi radialis brevis; ECU, extensor carpi ulnaris; FCR, flexor carpi radialis; FCU, flexor carpi ulnaris; PIP, proximal interphalangeal joint. From Zancolli EA. Structural and dynamic bases of hand surgery. 2nd edition. Philadelphia: JB Lippincott; 1979; with permission.
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forearm, wrist, and hand. Long-term follow-up of 25 patients [7] treated at a mean age of 8 years with a mean follow-up of 8 years, 7 months reported a final arc of motion of 44 of wrist extension and 19 of wrist flexion. Two patients required revision for overcorrection into a wrist extension/supination deformity. They recommended FCU to radial wrist extensor tendon transfer for patients who lack active wrist extension but who have good digital extension with the wrist passively extended above neutral. Newer concepts in determining optimal intraoperative tension have been described recently. Lieber et al [12] reported the use of intraoperative sarcomere length measurements and its relationship to tensioning of tendons during tendon transfer surgery. Because it is not possible to predict the relationship between passive tension and muscle length, these investigators have advocated the experimental use of an intraoperative device that allows measurement of sarcomere length as a basis for tensioning tendon transfers. Although this new measurement modality has been shown to be significant in an experimental model [13–16], it has not been tested specifically in the clinical setting. Whether transfers set at optimal sarcomere length are associated with improved functional outcomes remains to be studied. Another concern regarding the FCU transfer into the ECRB/L is the optimal vector for placement (ie, the extent to which the FCU origin should be released and the angle at which the tendon is inset). In the original description, Green [5] recommended the FCU transfer be into the ‘‘tendon of the ECRB to give more central action in dorsiflexion, whereas the tendon of the ECRL, which is more radial in position, gives a better direction of pull for supinator action and gives better correction of the ulnar deviation.’’ Cadaveric studies subsequently have shown that insertion into the ECRB versus the ECRL did not change the supination effect of the transfer significantly. Rather, freeing the muscle up to the proximal one third of the forearm gave it a less acute angle of insertion and increased its supination effect [17]. The FCR should not be used as a transfer for wrist extension, as it would provide a secondary pronation vector that would exacerbate the patient’s pronation deformity. In all cases of transfer into the wrist extensors, the finger function must be assessed preoperatively with the wrist in neutral, the desired postoperative position. If the finger flexors are too tight when the wrist is brought into neutral,
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a finger flexor lengthening will be necessary as part of the procedure. This is a common combination of procedures for many surgeons [18,19]. If the patient does not have finger extensor control to allow for release of grasped objects, a transfer into the finger extensors (EDC) may be indicated. Other series have found that transfer of the FCU into the EDC is rarely necessary [8,20], as balancing the wrist may be the key component to unmasking finger function.
Wrist stabilization If the patient has a severe wrist joint contracture limiting functional use of the hand (even as a paperweight), consideration should be given to a proximal row carpectomy (PRC) to shorten the skeleton or a wrist fusion to hold the wrist in a fixed, more functional position. The PRC is used in combination with tendon transfers and releases in patients in which passive extension of the wrist does not reach the neutral position. Passive mobility of the wrist is a necessary prerequisite to tendon transfer surgery, which aims to improve active mobility. Tonkin and Gschwind describe treatment of 34 patients with wrist and finger flexion deformities; four patients were treated with a combination of PRC, FCR, or FCU to ECRB, flexor aponeurotic release, and thumb and pronation procedures. The postoperative extension was 8 and all regained some ability to extend the fingers. Wrist fusion predictably maintains the wrist in a fixed position and usually is indicated for improved cosmesis and use of the hand as a paperweight in the skeletally mature individual [21]. The proximal carpal row can be removed as part of the wrist fusion to facilitate positioning of the wrist into slight extension [22], as shown in Fig. 2. Hargreaves et al [23] reported 11 wrist fusions in 10 patients treated at an average age of 18.8 years (range, 13–35). Concomitant PRC was performed in eight wrists and soft tissue releases in three. Improved function from preoperative ‘‘none’’ or ‘‘assist’’ levels was improved postoperatively to ‘‘assist’’ to ‘‘simple’’ function. Fusion was achieved in all cases, using plate fixation in nine patients and crossed K-wires (because of open physes) in two patients. Wrist fusion is contraindicated in the individual who uses wrist flexion tenodesis for release function, as this function would be lost if the wrist were to be fixed in a single position. It may be particularly beneficial when an athetoid component dominates.
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Finger surgery The most common finger deformities are the spastic flexion deformity and the swan neck deformity. Spastic flexion deformities causing a clenched fist need to be addressed in conjunction with the wrist flexion deformity. The flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) muscles are biarticular, crossing the wrist and finger joints. They thus need to be lengthened in concert with the wrist flexion deformity correction as part of a flexor pronator slide or with selective fascial lengthenings. The flexor pronator slide was described originally by Page [24] in 1923, reporting on six patients of whom two had cerebral palsy. Several subsequent reports [3,4] discuss the role of the flexor pronator slide in decreasing spastic forces in the wrist and finger flexors simultaneously and how this may unmask wrist and finger extension. For the more severe clenched fist deformity, cosmesis and hygiene may be the greater concern. Superficialis to profundus (STP) transfer is used to treat severe spastic flexion contractures of the hand. It is the treatment of choice in the nonfunctional hand with a spastic clenched fist deformity. Palma et al [25] have performed more than 75 STP transfers to relieve pain, improve hygiene, and ease daily activities for patients and caregivers and found the procedure to be effective, predictable, and safe. It was combined commonly with a wrist arthrodesis, carpal tunnel release, and ulnar motor neurectomy. Braun et al [26] reported that the STP operation ‘‘attained the limited goals set for this initial group of patients with severe flexion problems, who had little hope for restored function of individual flexor tendons. In twenty one patients, the resting position of the hand was improved.’’ They warn that release of the spastic
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extrinsic flexors may unmask intrinsic spasticity that may need to be addressed secondarily. In addition to release of the spastic flexors of the fingers, the question may arise as to whether tendon transfers may be necessary to augment finger extension. Smith [27] recommends tendon transfers for finger extension only after release procedures are completed to the wrist and fingers. Often it may take 6 months or longer until the tone of the digital extensors returns after the persistent stretch of the extensors has been released by lengthening of the flexors. Hoffer et al [28] reported 38 patients treated with tendon transfers to improve extension of the wrist and fingers. Twenty patients were treated with transfer of the FCU to the ECRB and 18 patients were treated with transfer of the FCU into the EDC. Of these 18 patients, 16 showed significant functional improvement. He recommended that the FCU be transferred to the EDC in patients with the apparent inability to release their hands (ie, cannot extend their digits with their wrist extended). Other series have found that transfer of the FCU into the EDC is rarely necessary [8,20], as balancing the wrist may be the key component to unmasking finger function. After clenched fist deformity, the next most common deformity seen is the swan neck. The pathophysiology of this deformity in cerebral palsy is the dynamic imbalance of the muscles acting on the proximal interphalangeal (PIP) joint, causing PIP joint hyperextension with distal interphalangeal joint flexion (Fig. 3). In cerebral palsy, swan neck deformities are caused by intrinsic muscle spasticity, often augmented by overactivity of the extrinsic finger extensors. Spasticity of the intrinsic muscles causes overpull of the lateral bands, accentuating PIP joint
b Fig. 1. (A) Preoperative view of dynamic wrist flexion deformity resulting in a poor active assist hand with significant disability for grasp and pinch functions. This 16-year-old girl had normal intelligence, moderate sensibility (10 of 12 objects stereognosis function), and high motivation. No active wrist extension was present preoperatively, with good control of active finger extension. She showed good preoperative selective control of the FCU despite its spasticity. (B) Through a longitudinal incision extending the distal two thirds of the forearm along the ulnar border, the FCU was harvested from its insertion. (C) A curvilinear incision over the radial wrist extensors was used for weaving the FCU into the ECRB just proximal to the extensor retinaculum. The same incision was used as part of the EPL rerouting. A separate incision was used in the antecubital fossa for a biceps lengthening and brachialis fascial release. (D) The FCU is harvested off its pisiform insertion and freed from its fascial attachments. (E) The FCU tendon is transferred dorsally, removing it as a wrist flexor and providing its force as an active wrist extensor. The tendon is tensioned so that the wrist lies antigravity at rest in a neutral position. (F) Following the procedure, active wrist extension was achieved for effective grasp. Finger function was good for release. Good active assist function was achieved.
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Fig. 2. (A) Preoperative radiographs of a fixed flexion wrist contracture in a skeletally mature 17-year-old boy. Note the finger extension present preoperatively, indicating minimal finger flexor contractures. (B) Proximal row carpectomy combined with wrist fusion by plating was used. Adequate finger excursion was present so that concomitant finger flexor lengthening was not necessary in this case.
extension. With chronic intrinsic spasticity, overpull of the lateral band causes incompetence of the transverse retinacular ligament, stretching of the PIP joint volar plate, and resultant dorsal subluxation of the lateral bands. Additionally, some patients with cerebral palsy have better volitional control of their extrinsic finger extensors than they have of their wrist extensors. Patients thus attempt to extend their wrists through activation of their extrinsic finger extensors, causing metacarpophalangeal (MCP) joint extension and exacerbating PIP joint hyperextension (swan-necking).
Finally, excessive lengthening or surgical release of the FDS, such as used in the STP transfer, often unmasks intrinsic spasticity, resulting in significant swan neck deformities, as the flexion forces on the PIP joint are diminished iatrogenically. The indication for surgical correction is locking swan neck deformities (usually greater than 40 ) that are not responsive to splinting and that interfere with function. For the patient with significant wrist flexion deformities and only mild swan-necking, surgical correction of wrist position alone may be
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Fig. 3. (A) Pathophysiology of swan neck deformity in cerebral palsy. In cerebral palsy, the intrinsic muscles are spastic. The extrinsic finger extensors are overactive in their attempt to augment wrist extension when a wrist flexion deformity exists. Intrinsic spasticity combined with extrinsic overpull causes PIP joint hyperextension with resultant incompetency of the transverse retinacular ligament and volar plate. PIP joint hyperextension concentrates the extension forces at the PIP joint with slackening of the terminal tendon allowing DIP joint flexion. (B) This patient exhibits swan neck deformities that lock in extension and inhibit his abilities to grasp his walker.
adequate for treatment. For the patient with severe swan necking (>40 ), rebalancing of the muscle forces at the PIP joint is necessary. Surgical options include lateral band rerouting [29,30], lateral band tenodesis [31], superficialis tenodesis [32], spiral oblique ligament reconstruction [33], intrinsic muscle slide [34], or a resection of the ulnar nerve motor branch in Guyon’s canal [35]. The author’s preferred method is the lateral band rerouting procedure shown in Fig. 4, because it requires less extensive dissection and rebalances the intrinsic and extrinsic tendon deforming forces.
Summary The surgical results of upper extremity intervention have been shown to improve hand function from paperweight/passive assist function to active assist function [20]. Although children with cerebral palsy commonly have a sensibility
deficiency in conjunction with their motor deficiency [36,37], several recent studies have disproved the previous doctrine that hand surgery should not be performed on children with sensibility deficiencies. The author’s report [20] of 134 children treated surgically showed that preoperatively 50% had impaired two-point discrimination and 75% had impaired stereognosis; impaired sensibility had no adverse effect on surgical results. Eliasson et al [18] reported on 32 children treated surgically with tendon transfers and muscle releases. Impaired sensibility before the surgery did not influence the outcome. In fact, Dahlin et al [38] reported 36 patients treated operatively and followed for 18 months, finding an improvement in stereognosis function associated with the improvement in their motor function, presumably because of improved functional use. Children with cerebral palsy can improve their motor function and perhaps also their sensibility function with appropriately planned and executed
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Fig. 4. (A) The extensor mechanism is incised longitudinally in the interval between the central slip and the lateral band to allow the volar mobilization of the lateral band to the level of the volar plate. The A3 pulley is opened and sutured closely around the lateral band, anchoring the lateral band volar to the axis of the PIP joint. The rerouting is tensioned so that the PIP has light resistance to extension past 30 of flexion and does not extend past 5 of flexion. (B) Following lateral band rerouting, this patient can actively extend his fingers without locking and can grasp his walker effectively.
tendon release and transfer surgery. Balance of the wrist and fingers is the key element in improvement of upper limb function.
[4]
References
[5]
[1] Zancolli EA. Structural and dynamic bases of hand surgery. 2nd edition. Philadelphia: JB Lippincott; 1979. [2] Van Heest A. Applications of botulinum toxin in orthopedics and upper extremity surgery. Tech Hand Upper Extrem Surg 1997;1(1):27–34. [3] Inglis AE, Cooper W. Release of the flexor-pronator origin for flexion deformities of the hand and
[6]
[7]
wrist in spastic paralysis. A study of eighteen cases. J Bone Joint Surg 1966;48A(5):847–57. White WF. Flexor muscle slide in the spastic hand: the Max Page operation. J Bone Joint Surg 1972; 54B(3):453–9. Green WT. Tendon transplantation of the flexor carpi ulnaris for pronation-flexion deformity of the wrist. Surg Gynecol Obstet 1942;75:337–42. 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(6):836–40. Thometz JG, Tachdjian M. Long-term follow-up of the flexor carpi ulnaris transfer in spastic hemiplegic children. J Pediatr Orthop 1988;8(4):407–12.
A.E. Van Heest / Hand Clin 19 (2003) 657–665 [8] Tonkin M, Gshwind C. Surgery for cerebral palsy: part 2. Flexion deformity of the wrist and fingers. J Hand Surg 1992;17B(4):396–400. [9] Wenner SM, Johnson KA. Transfer of the flexor carpi ulnaris to the radial wrist extensors in cerebral palsy. J Hand Surg 1988;13A(2):231–3. [10] Wolf TM, Clinkscales CM, Hamlin C. Flexor carpi ulnaris tendon transfers in cerebral palsy. J Hand Surg 1998;23B(3):340–3. [11] El-Said NS. Selective release of the flexor origin with transfer of flexor carpi ulnaris in cerebral palsy. J Bone Joint Surg 2001;83B(2):259–62. [12] Lieber RL, Friden J. Intraoperative measurement and biomechanical modeling of the flexor carpi ulnaris-to-extensor carpi radialis longus tendon transfer. J Biomech Eng 1997;119(4):386–91. [13] Burkholder TJ, Lieber RL. Sarcomere length operating range of vertebrate muscles during movement. J Exp Biol 2001;204(Pt 9):1529–36. [14] Friden J, Lieber RL. Spastic muscle cells are shorter and stiffer than normal cells [comment]. Muscle Nerve 2003;27(2):157–64. [15] Friden J, Lieber RL. Tendon transfer surgery: clinical implications of experimental studies. Clin Orthop 2002;403(Suppl):S163–70. [16] Friden J, Ponten E, Lieber RL. Effect of muscle tension during tendon transfer on sarcomerogenesis in a rabbit model. J Hand Surg 2000;25A(1):138–43. [17] Van Heest AE, Murthy NS, Sathy MR, Wentorf FA. The supination effect of tendon transfer of the flexor carpi ulnaris to the extensor carpi radialis brevis or longus: a cadaveric study. J Hand Surg 1999;24A(5):1091–6. [18] Eliasson AC, Ekholm C, Carlstedt T. Hand function in children with cerebral palsy after upper-limb tendon transfer and muscle release [comment]. Dev Med Child Neurol 1998;40(9): 612–21. [19] Wright T. Tendon transfer for wrist flexion deformity in cerebral palsy. Atlas Hand Clin 2002; 7:133–51. [20] Van Heest AE, House JH, Cariello C. Upper extremity surgical treatment of cerebral palsy. J Hand Surg 1999;24A(2):323–30. [21] Hoffer MM, Zeitzew S. Wrist fusion in cerebral palsy. J Hand Surg 1988;13A(5):667–70. [22] Louis DS, Hankin FM, Bowers WH. Capitateradius arthrodesis: an alternative method of radiocarpal arthrodesis. J Hand Surg 1984;9A(3):365–9.
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[23] Hargreaves DG, Warwick DJ, Tonkin MA. Changes in hand function following wrist arthrodesis in cerebral palsy. J Hand Surg 2000;25B(2):193–4. [24] Page CM. An operation for the relief of flexion contracture in the forearm. J Bone Joint Surg 1923; 5A:233–4. [25] Palma D, Fuller D, Keenan MA. Superficialis to profundus tendon transfer. Atlas Hand Clin 2002; 7:153–62. [26] Braun RM, Vise GT, Roper B. Preliminary experience with superficialis-to-profundus tendon transfer in the hemiplegic upper extremity. J Bone Joint Surg 1974;56(3):466–72. [27] Smith RJ. Tendon transfers of the hand and forearm. Boston: Little, Brown & Company; 1987. [28] 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(6):836–40. [29] Tonkin MA, Hughes J, Smith KL. Lateral band translocation for swan-neck deformity. J Hand Surg 1992;17A(2):260–7. [30] Van Heest A. Lateral band re-routing in the treatment of swan neck deformities due to cerebral palsy. Tech Hand Upper Extrem Surg 1997;1: 189–94. [31] Littler JW. The finger extensor mechanism. Surg Clin N Am 1967;47:415–32. [32] Swanson AB. Surgery of the hand in cerebral palsy and the swan-neck deformity. J Bone Joint Surg 1960;42A(6):951–64. [33] Thompson JS, Littler JW, Upton J. The spiral oblique retinacular ligament (SORL). J Hand Surg 1978;3A(5):482–7. [34] Zancolli EA, Zancolli ER Jr. Surgical management of the hemiplegic spastic hand in cerebral palsy. Surg Clin N Am 1981;61(2):395–406. [35] Manske PR. Cerebral palsy of the upper extremity. Hand Clin 1990;6(4):697–709. [36] Van Heest AE, House J, Putnam M. Sensibility deficiencies in the hands of children with spastic hemiplegia. J Hand Surg 1993;18A(2):278–81. [37] Waters PM, Van Heest A. Spastic hemiplegia of the upper extremity in children. Hand Clin 1998;14(1): 119–34. [38] Dahlin LB, Komoto-Tufvesson Y, Salgeback S. Surgery of the spastic hand in cerebral palsy. Improvement in stereognosis and hand function after surgery. J Hand Surg 1998;23B(3):334–9.