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Cerebral Palsy of the Hand
Cerebral palsy is a nonprogressive, nonhereditary encephalopathy that occurs in the prenatal or perinatal period and is characterized by altered motor, sensory, and, often, intellectual function. Cerebral palsy occurs in the industrialized world with an approximate annual frequency of 2 per 1000 live births. The most common motor disability of childhood, cerebral palsy can be caused by fetal stroke, anoxia, infection, teratogens, central nervous system malformations, metabolic diseases, and prematurity. Epidemiologic studies suggest that cerebral palsy is predominantly metabolic and not caused by neonatal ischemia. Approximately 75% of cases occur in utero, 5% during delivery, and 15% to 20% after delivery. Multiple-gestation pregnancies and intrauterine infections are other common risk factors. It can be classified as pyramidal, which includes spastic hemiplegia, diplegia, paraplegia, and quadriplegia, or as extrapyramidal, which includes athetoid and ataxic patterns. A mixed variety also occurs with spasticity and athetosis (see Chapter 33 ). Hand function is impaired to some extent in all types except possibly spastic paraplegia, with the most common deformities being shoulder adduction, internal rotation, elbow flexion, forearm pronation, wrist and finger flexion, thumb-in-palm, and swan-neck deformities ( Fig. 72.1 ). Many surgical procedures have been performed in an attempt to correct these deformities. Earlier results were unpredictable and disappointing, primarily because of inappropriate patient selection. The extensive works of Green, Goldner, Swanson, Zancolli et al., and Hoffer et al. have proved certain principles in the evaluation and management of the cerebral palsied hand.
Typical upper extremity deformities in cerebral palsy: elbow flexion, forearm pronation, and wrist and finger flexion.
Patient Evaluation
Most patients with cerebral palsy exhibit full passive range of motion at birth, but joint stiffness and contractures develop gradually, leading to variability at the time of presentation that depends on severity, location, and extent of brain injury, associated neurologic disorders, and baseline cognitive motor function. Careful repeated evaluations, often over a considerable length of time, are required before surgery can be advised or discouraged. Important information includes any birth or perinatal medical problems, achievement of developmental milestones, and especially the degree with which the child has previously used the hand. If the hand is completely ignored by the child, it is doubtful that function would be restored or improved with surgery. The early development of handedness may be especially helpful because it is uncommon before the age of 3 years and may represent some degree of particular weakness or incoordination in the less preferred extremity. The particular cerebral lesion should be identified and characterized as pyramidal with associated spasticity or extrapyramidal, because children with athetoid patterns are not surgical candidates. The persistence of any infantile postural reflexes should be documented. Deformities should be classified as static contractures (deformities that do not correct with compensatory positioning of muscle or joint) or dynamic deformities that are spastic and slowly correctable. Volkmann angle for finger flexor tightness ( Fig. 72.2 ) should be assessed and documented. This is done by bringing the wrist from maximum palmar flexion into extension with the digits extended. The angle at which the digits move into a flexed posture is the Volkmann angle. Most children show dynamic deformities early in life; if left untreated, these deformities may progress to static contractures.
Muscle examination should determine the degree of spasticity, strength, and coordination of each major muscle, with special attention given to the child’s ability to pinch, grasp, and release objects. The patient also should have sufficient proximal control of the extremity to place the hand voluntarily on top of the head and then on the opposite knee within 5 to 10 seconds. If a child does not show this degree of control, it is doubtful that he or she would use the extremity enough to justify reconstruction.
The sensibility pattern of the hand should be determined. Although most patients have intact epicritic sensation (the ability to discern pinprick, heat, and cold), about half have impaired sensibility, with diminished two-point discrimination, stereognosis, and proprioception. Because sensibility in the hand is so important in determining the prognosis after surgery, its status should be evaluated as accurately as possible before surgery. An indication may be gained by observing whether the hand is used or ignored; unless motor coordination is extremely poor, an ignored hand probably indicates the absence of sensibility. Further evaluation requires communication with the child, and this usually is impossible before 4 years of age. A cursory examination can be done by asking a blindfolded child to differentiate between a sphere and a cube or to indicate the position of the hand when the palm has been placed by the examiner facing upward or downward. A more detailed examination testing recognition of blunt and sharp points, of familiar objects such as coins, and of differences in temperature also is valuable. Examination of the contralateral extremity has been shown to be an important part of patient evaluation. Dexterity of the contralateral extremity also can be affected in patients with hemiplegia and may require intervention to improve overall function.
Further evaluation using dynamic electromyography may be helpful in determining which muscles are in phase with the function to be augmented and allow for appropriate donor muscle selection. After evaluation, the child’s function and deformity can be described according to several available classification systems, including the House functional classification and the Manual Ability Classification System (MACS) ( Tables 72.1 and 72.2 ). MACS level appears to be a strong predictor of contracture development. Patients with MACS level V have a 17 times greater risk of contracture than patients with MACS level I. Passive range of motion diminishes with age, with contractures occurring in one third of children overall. Neuromuscular blocking agents, such as 1% lidocaine, 0.25% bupivacaine, and 45% ethanol, are helpful in assessing weaker muscle groups without the overbearing effect of antagonist muscles and can assist in predicting surgical outcome after tendon lengthening or tenotomy. The classic presentation of established spastic hemiplegia is adduction, internal rotation of the shoulder, elbow flexion, forearm pronation, wrist and finger flexion, thumb-in-palm deformity, and swan-neck deformity of the fingers.
TABLE 72.1
Functional Classification of House et al.
From Van Heest AE, House JH, Cariello C: Upper extremity surgical treatment of cerebral palsy, J Hand Surg 24A:323, 1999.
| Level | Category | Description |
|---|---|---|
| 0 | Does not use | Does not use |
| 1 | Poor passive assist | Uses as stabilizing weight only |
| 2 | Fair passive assist | Can hold object placed in hand |
| 3 | Good passive assist | Can hold object and stabilize it for use by other hand |
| 4 | Poor active assist | Can actively grasp object and hold it weakly |
| 5 | Fair active use | Can actively grasp object and stabilize it well |
| 6 | Good active assist | Can actively grasp object and manipulate it |
| 7 | Spontaneous use, partial | Can perform bimanual activities and occasionally uses the hand spontaneously |
| 8 | Spontaneous use, complete | Uses hand completely independently without reference to the other hand |
TABLE 72.2
Summary of Manual Ability Classification System
From Arner M, Eliasson AC, Nicklasson S, et al: Hand function in cerebral palsy: report of 367 children in a population-based longitudinal health care program, J Hand Surg 33A:1337, 2008.
| Macs Level | Description |
|---|---|
| I | Handles most objects easily and successfully |
| II | Handles most objects with somewhat reduced quality or speed of achievement |
| III | Handles objects with difficulty; needs help to prepare or modify activities |
| IV | Handles a limited selection of easily managed objects in adapted situations |
| V | Does not handle objects and has severely limited ability to perform even simple actions |
MACS , Manual Ability Classification System.
Nonoperative Management
Traditionally, early splinting has been used to prevent fixed contractures of the muscles and joints; however, many surgeons have now abandoned this method because fixed contractures rarely occur in young children and because during sleep the upper extremity often is relaxed and supple, obviating the need for night splinting. Daytime splinting is cumbersome and often is rejected by an active child. If splinting is necessary, a well-formed splint without pressure points should hold the wrist in as much extension as tolerated with the fingers in almost complete extension and the thumb out of the palm ( Fig. 72.3 ). A functional orthosis that provides wrist extension and thumb abduction has been found to improve measured hand function.
Hand therapy, although rarely successful in training a child to relax spastic muscles, strengthens weakened muscles and controls exaggerated reflexes. Therapy also is invaluable in providing support to the patient and family in dealing with the disorder, in evaluating patients for surgical procedures, and in postoperative recovery of functional activities.
Electrical stimulation aimed at strengthening nonspastic but weak extensor compartment muscles may have a role in nonoperative management. Previous reports have yielded conflicting results. Improvement has been reported with electrical stimulation and dynamic splinting; however, a lifelong application of the program is necessary.
Interest in the use of botulinum type A toxin in the treatment of cerebral palsy has increased. Decreasing spasticity should help to improve control of movement patterns through a combination of lengthening muscle groups, improving posture, and strengthening antagonistic muscles. Several studies have shown promising short-term results. In a randomized double-blind placebo-controlled study, Koman et al. demonstrated that children receiving multiple botulinum toxin A (BoNT-A) injections developed significant short-term improvements in upper extremity function without complications. In one 20-year study involving patients with MACS IV and V, Andersson et al. demonstrated that adjunctive Botox, movement training, and orthoses helped prevent significant loss of passive range of motion when started at an early age. Other long-term follow-up studies need to be conducted, however, to determine if there is any long-term functional improvement, or any possible resistance or allergic complications. Dramatic improvement has been shown but results are temporary (6 to 9 months). The most common reasons for failure are fixed joint contractures, absence of selective motor control in antagonist muscles, sensory impairment, and learned nonuse. In a smaller randomized controlled study, patients treated with BoNT-A injections in combination with occupational therapy showed improved function when compared with occupational therapy alone.
Operative Management
Goals
The goals of operative treatment in a child with cerebral palsy should be specific and should be aimed at providing useful grasp and release and acceptable hygiene ( Fig. 72.4 ). Sometimes improving the appearance of the hand by correcting an unsightly contracture may be a modest goal as well. Fine manipulation rarely is improved by surgery, and normal hand function is an unrealistic goal. Grasp and release are possible only in children who have at least sufficient sensibility to allow an awareness of the extremity. Stereognosis has been shown to improve with postoperative gains in motor function and functional use of the upper extremity. Undercorrection rather than overcorrection of the deformity or dysfunction is always preferred.
Principles
The ideal candidate for surgery is a spastic hemiplegic who is cooperative, intelligent, motivated to participate with postoperative rehabilitation protocol, and who has a pattern of grasp and release so functional that the hand is already useful to some extent; the hand should be reasonably sensitive, and the patient should be between 5 and 25 years old. In contrast, a poor candidate for surgery is a patient who is severely mentally delayed or disabled and who has definite athetosis in the extremity, a hand that has developed joint contractures and is insensitive, a wrist that passively cannot be brought to neutral, and fingers that cannot be extended even when the wrist is flexed. Children with spastic diplegia rarely have sufficient upper extremity spasticity to warrant surgery, and children with spastic quadriplegia or total body involvement have too little voluntary control to benefit from surgery aimed at improving grasp and release; however, they may benefit from surgery that improves hygiene.
Surgical options include myotomy, tenotomy, tendon lengthening, tendon transfer, tenodesis, capsulotomy, excisional arthroplasty, and arthrodesis. Tendon lengthening requires no particular compliance and can be performed in spastic and athetoid patients. It weakens the muscle and diminishes its excursion and stretch reflex, which subsequently diminishes spasticity, allowing antagonistic muscles to influence function to a greater extent. Tendon transfers require some postoperative compliance, should be synergistic, cannot overcome fixed deformity, and are not reliable in athetoid patients. Arthrodesis is useful in stabilizing the thumb metacarpophalangeal joint during reconstruction of a thumb-in-palm deformity and in correcting fixed flexion deformities of the wrist when sacrifice of its “windlass” effect is believed justifiable.
As to when the various types of operations may be indicated, myotomies are likely to be effective at the earliest age, tendon transfers later, and arthrodeses even later. Soft-tissue operations to correct flexion deformity of the wrist and pronation deformity of the forearm are probably indicated earliest. As a rule, indicated surgery usually is carried out at 4 to 8 years of age and ideally before significant contractures develop.
One study found that patients who had poor voluntary motor control had less improvement after surgery than patients with fair-to-good voluntary control. This was the only prediction of outcome after surgical intervention. Some literature would suggest that although surgical intervention can improve function, it may not provide improved ability to perform activities of daily living. Appropriate patient selection is of upmost importance, and a multidisciplinary approach is optimal. Using careful assessment for surgical eligibility and a multiple disciplinary approach, clinically relevant functional and cosmetic goals can be achieved ( Table 72.3 ).
TABLE 72.3
Surgical Procedures for Upper Limb Deformities
From Waters PM, Bae DS: Pediatric hand and upper limb surgery. A practical guide , Philadelphia, 2012, Lippincott Williams and Wilkins, Table 22.1 , pp 219–236.
| Elbow Flexion | Forearm Pronation | Wrist Flexion/Ulnar Deviation | Thumb-In-Palm | Finger Deformities | |
|---|---|---|---|---|---|
| Tendon releases | Lacertus fibrosus release BR release Biceps lengthening Brachialis lengthening |
PT release | Flexor pronator slide FCR tenotomy or lengthening FCU tenotomy or lengthening |
Adductor release FPB release FPL lengthening |
FDS lengthening FDP lengthening Flexor pronator Slide |
| Tendon transfers | PT rerouting | FCU to ECRB FCU to EDC BR to ECRB ECU centralization |
PL to AbPL, EPB, or EPL BR to AbPL, EPB, or EPL FCR to AbPL, EPB, or EPL AbPL tenodesis EPL rerouting |
Lateral band rerouting (swan neck) FDS tenodesis (swan neck) STP transfer |
|
| Joint stabilization | Wrist fusion PRC |
MCP fusion MCP capsulodesis IP fusion |
PIP fusion (rare) |
AbPL, Abductor pollicis longus; BR, brachioradialis; ECRB , extensor carpi radialis brevis; ECU , extensor carpi ulnaris; EDC, extensor digitorum communis; EPB , extensor pollicis brevis; EPL , extensor pollicis longus; FCR , flexor carpi radialis; FCU , flexor carpi ulnaris; FDP , flexor digitorum profundus; FDS , flexor digitorum superficialis; FPB , flexor pollicis brevis; FPL , flexor pollicis longus; IP , interphalangeal; MCP , metacarpophalangeal; PIP , proximal interphalangeal; PL , palmaris longus; PRC , proximal row carpectomy; PT , pronator teres; STP , superficialis-to-profundus.
Pronation Contracture of the Forearm
Pronation deformity of the forearm is common and disabling in children with cerebral palsy and is caused by spasticity of the pronator teres and, at times, of the pronator quadratus. It can be aggravated by lengthening of the biceps tendon for elbow flexion contracture, and it can be improved by simple tenotomy of the insertion of the pronator teres. If the patient lacks supination just short of neutral and the pronator is contracted and fires out of phase with supination, then a simple pronator teres tenotomy is ideal. A pronation contracture also may be aggravated by a contracted biceps aponeurosis, and division of this structure may improve supination. Supination also can be improved by transfer of the flexor carpi ulnaris around the ulnar side of the forearm during augmentation of the extensor digitorum communis or the extensor carpi radialis brevis. However, overcorrection with supination contracture can occur postoperatively if the procedure is combined with a pronator teres release or transfer. Sakellarides et al. devised an operation principally to correct pronation contracture of the forearm. According to them, transferring the pronator teres tendon produces better correction than any other transfer. This method corrects one deforming force while providing a force for supination. The tendon is released, rerouted around the radius, and inserted into the bone. In their series of 22 patients so treated, 82% gained an average of 46 degrees of active supination. Bunata found similar improvement in 31 patients, with the average active supination improving 65 degrees and the average dynamic positioning changing from 26 to 7 degrees. The indication for surgery was a pronation positioning of 25 degrees or greater because this prevented the child from grasping a cup full of water. Ozkan et al. described a brachioradialis rerouting procedure in combination with a pronator teres and quadratus release in a small series of patients with an average gain of 81 degrees of supination and no overcorrection. However, Čobeljić et al. did not find benefit to pronator quadratus release at 17.5-year follow-up. Gschwind and Tonkin classified pronation deformities into four groups to help guide surgical recommendations ( Table 72.4 ). One should also note that transfer of the flexor carpi ulnaris to extensor carpi radialis will add to the supination moment and should be taken into consideration when contemplating pronator teres release versus rerouting.
TABLE 72.4
Gschwind Classification of Pronation Deformities as a Guide to Surgical Recommendations
| Classification (Group) | Pronation deformity | Surgical recommendation |
|---|---|---|
| 1 | Active supination beyond neutral | No specific surgery |
| 2 | Active supination to or less than neutral | Pronator quadratus release with or without a flexor aponeurotic release |
| 3 | No active supination, yet free passive supination | Pronator teres rerouting procedure |
| 4 | No active supination and only limited passive supination | Pronator quadratus release and a flexor aponeurotic release ∗ |
∗ If after release no active supination is possible, a pronator teres rerouting may be added. Gschwind and Tonkin caution against performing a pronator teres transfer at the same time as a pronator quadratus release because an undesirable supination deformity may ensue.
Transfer of the Pronator Teres
Technique 72.1
- ▪
Make a zigzag, curvilinear, or straight longitudinal incision over the anterior and radial aspects of the midforearm centered over the insertion of the pronator teres ( Fig. 72.5A ).
- ▪
Protect the lateral cutaneous nerve of the forearm and the superficial radial nerve.
- ▪
Identify and develop the interval between the brachioradialis and extensor carpi radialis longus.
- ▪
Identify the oblique fibers that insert into bone at the musculotendinous insertion of the pronator teres ( Fig. 72.5B ). Use sharp dissection to detach the insertion of the pronator teres, along with an attached strip of periosteum ( Fig. 72.5C ). Mobilize the muscle extraperiosteally, well proximal in the forearm.
- ▪
Free the interosseous membrane from the radius as far as necessary to gain maximal passive supination.
- ▪
Pass a right-angle clamp from the dorsolateral aspect of the radius through the interosseous membrane and use it to transfer the pronator teres through the interosseous membrane in a volar-to-dorsolateral direction.
- ▪
At the same level as the previous muscle insertion, drill an anchoring hole on the anterolateral aspect of the radial cortex ( Fig. 72.5D ). Drill a smaller hole through the posteromedial part of the radius using a 1.6-mm Kirschner wire. Enlarge the hole in the anterolateral cortex to 2.8 mm.
- ▪
Pass a suture with the tendon attached through the two holes from anteromedial to posterolateral ( Fig. 72.5E ). In this manner, the tendon is introduced into the larger hole on the anterolateral cortex and is secured ( Fig. 72.5F,G ). Apply further stay sutures through the tendon as indicated.
- ▪
Hold the forearm in approximately 45 degrees of supination and snug the tendon up to hold this position. Allow the brachioradialis to fall into place and close the incision.
- ▪
Apply a long arm cast, maintaining the elbow in 45 degrees of flexion and the forearm in 60 degrees of supination. Elevate the arm immediately after surgery.
Postoperative Care
The sutures are removed at 2 weeks, and a new long arm cast that maintains forearm supination is applied and is worn for another 4 weeks. Supination splinting at night is continued for 6 months.
Brachioradialis Rerouting
Technique 72.2
(OZKAN ET AL.)
- ▪
Make a longitudinal incision on the radial aspect of the forearm to provide access to the brachioradialis, pronator teres, and pronator quadratus muscles. If additional procedures, such as flexor tendon lengthening, are also being performed, make a curvilinear incision on the palmar surface of the forearm.
- ▪
Develop the skin flaps and retract.
- ▪
Using monopolar diathermy, release the pronator quadratus muscle from its radial attachment by cutting through its muscle belly.
- ▪
Isolate the pronator teres tendon and divide in a Z fashion for lengthening.
- ▪
Suture the tendon ends with the forearm in neutral position and without any tension within the tendon. It is crucial not to overlengthen this tendon so as to preserve pronator function and prevent supination deformity.
- ▪
Identify the superficial branch of the radial nerve and artery and retract in the distal forearm.
- ▪
Prepare the brachioradialis tendon and muscle for transfer, preserving its distal attachment. It is important that the muscle is completely freed from all its fascial attachments because otherwise muscle excursion will be insufficient.
- ▪
Preserving the neurovascular structures of the muscle, the brachioradialis tendon is divided with a long Z-plasty to provide sufficient tendon length for rerouting ( Fig. 72.6A ).
- ▪
Pass the distal tendon end of the brachioradialis through a window created in the interosseous space, volar to dorsal, ulnar to radial direction, just proximal to the pronator quadratus muscle ( Fig. 72.6B ).
- ▪
Retract the radial artery and pass the tendon deep to this to avoid compression.
- ▪
Suture the proximal and distal tendons to each other with a Pulvertaft weave with the elbow at 90 degrees of flexion.
- ▪
Keep the forearm in neutral during reattachment without any tension on the tendon ends.
- ▪
Close the skin with absorbable sutures and apply an above-elbow plaster cast with the elbow in 90 degrees flexion and the forearm in neutral. Cast the wrist and fingers as necessary if additional procedures have been performed.
Postoperative Care
The hand is elevated for 48 hours. Peripheral circulation should be closely monitored. The cast is worn for 4 weeks, after which time it is replaced with a splint that can be removed periodically for physical therapy. The splint is discontinued during the day after another 8 weeks but is applied at night for 4 additional weeks. Subsequently, the patient is encouraged to use the extremity in activities of daily living.
Flexion Deformities of the Wrist and Fingers
The most frequent deformities in the upper extremity in spastic paralysis are those of flexion of the wrist and fingers. These deformities usually are accompanied by pronation of the forearm, flexion of the elbow, and the thumb-in-palm deformity. Zancolli et al. classified spastic flexion deformities of the wrist and hand into three patterns ( Table 72.5 ):
-
-
Pattern 1. The fingers can be actively extended with the wrist in less than 20 degrees of flexion. This is a fairly mild deformity in which grasp and release are possible. Extension of the wrist is impossible with the fingers in full extension. Consideration may be given to flexor carpi ulnaris tenotomy combined with lengthening of the finger flexors, preferably by tenotomy at the musculotendinous junction, allowing for selective fractional lengthening as required. A flexor slide also can be selected.
-
Pattern 2. Active finger extension is possible only with the wrist in more than 20 degrees of flexion. This pattern is divided further into two subgroups. In pattern 2a, the patient has voluntary wrist extension with the fingers in flexion, indicating that the wrist extensors are active and the finger flexors are not severely spastic. In pattern 2b, the patient is unable to extend the wrist with the fingers in flexion, indicating that the wrist extensors are paralyzed and require augmentation to improve function. In pattern 2, lengthening of the finger flexors, combined with a tendon transfer to augment finger or wrist extension, should be considered. The classic transfer is of the flexor carpi ulnaris to the extensor carpi radialis brevis, which improves supination, wrist extension, and finger flexion (grasp). If weakness in finger extension (release) is considerable, transfer into the extensor digitorum communis is preferred. Preoperative electromyography may be useful to determine in which phase the donor muscle is active: grasp or release. Another alternative is to fractionally lengthen the flexor carpi ulnaris and flexor carpi radialis and transfer the extensor carpi ulnaris into the extensor carpi radialis brevis to improve wrist extension power.
-
Pattern 3. The patient has severe flexion deformities and is unable to extend the fingers or wrist actively even when starting from a position of maximal flexion. Hand sensibility usually is poor. Surgery would not improve function but may improve hygiene. Tenotomy of the wrist flexors and sublimis-to-profundus transfers as described by Braun and Vice may be considered. Wrist arthrodesis and carpectomy may improve appearance in these severe deformities.
-
TABLE 72.5
Classification of Flexion Deformities of Wrist and Fingers
From Van Heest AE: Surgical management of wrist and finger deformity, Hand Clin 19:657, 2003.
| Classification (Group) | Deformity |
|---|---|
| 1 | Active finger extension with <20 degrees of wrist flexion |
| 2 | Active finger extension with >20 degrees of wrist flexion |
| 2a | Active wrist extension with fingers flexed |
| 2b | No active wrist extension with fingers flexed |
| 3 | Wrist and finger extension absent even with full wrist flexion |
Fractional Lengthening of the Flexor Carpi Radialis Muscle and Finger Flexors
Technique 72.3
- ▪
Begin a curved volar incision over the forearm about 3 cm proximal to the volar wrist crease and continue it proximally for 6 cm.
- ▪
Identify the flexor carpi radialis muscle and follow it proximally to the musculotendinous junction and farther proximally until the muscle belly is identified. The distal portion of the muscle belly is surrounded by an aponeurosis that thickens distally and forms the tendon of the muscle.
- ▪
Lengthen the muscle-tendon unit and leave it in continuity by making transverse cuts in the aponeurosis proximal to the musculotendinous junction. Completely identify the muscle circumferentially and make a transverse cut through the aponeurosis but not through the muscle ( Fig. 72.7 ). Divide the aponeurosis transversely and do not leave any of the tendon intact; otherwise, the muscle-tendon unit does not lengthen.
- ▪
After the cut in the aponeurosis is made, place the wrist in dorsiflexion. The transverse cut in the aponeurosis widens as the muscle lengthens, but the entire muscle-tendon unit remains intact. A second cut for recession can be made if necessary.
- ▪
Other musculotendinous units may be contracted in addition to the flexor carpi radialis muscle. Frequently, the palmaris longus muscle also is spastic and contracted and may require lengthening in the same manner.
- ▪
Through this same incision, the finger flexors can be lengthened in a similar manner. First lengthen the flexor digitorum sublimis muscles and then the flexor digitorum profundus if they contribute to the contracture.
Postoperative Care
A palmar (volar) short arm splint with the wrist in neutral position or slightly extended is worn for 3 to 4 weeks. Then mobilization of the wrist is begun, and a removable splint is used for protection. A volar short arm night splint is used for an additional 4 to 6 months.
Release of the Flexor-Pronator Origin
Release of the flexor-pronator origin may improve appearance and function of a hand with severe flexion deformities of the wrist and fingers. It is not indicated in hands that can be corrected passively but assume a flexed position during grasp; for these, less extensive operations, such as transfer of the flexor carpi ulnaris to a wrist extensor, are more useful. Release of the flexor-pronator origin was first described by Page in 1923 and later by Inglis and Cooper and by Williams and Haddad. Ezaki recommended a flexor-pronator slide if more than 45 degrees of wrist flexion is required to extend the fingers.
Technique 72.4
(INGLIS AND COOPER)
- ▪
Make an incision over the anterior part of the medial epicondyle of the humerus beginning 5 cm proximal to the epicondyle and continuing distally to the midpoint of the forearm over the ulna ( Fig. 72.8A ). The medial antebrachial cutaneous nerve often is seen in the distal part of the incision, and the medial brachial cutaneous nerve can be seen posterior to the medial part of the epicondyle.
- ▪
Identify the ulnar nerve proximal to the epicondyle, dissect and elevate it from its groove behind the epicondyle, and carefully free it distally ( Fig. 72.8B ). Identify, free, and protect the branches of the ulnar nerve to the flexor carpi ulnaris and to the two ulnar heads of the flexor digitorum profundus.
- ▪
To release the origins of the flexor carpi ulnaris and flexor digitorum profundus, begin distally at about the middle of the ulna and elevate both muscles from the bone at the subcutaneous border; the interosseous membrane is seen around the volar surface of the bone. Continue proximally along the ulna as far as the ulnar groove at the epicondyle. During this dissection, the interosseous membrane and the fascia of the brachialis muscle are seen in the depths of the wound.
- ▪
Replace the ulnar nerve in its groove and divide the entire flexor-pronator muscle mass at its origin from the medial part of the epicondyle. At this point, the median nerve can be seen as it passes through the pronator teres.
- ▪
Continue the dissection anteriorly over the flexor aspect of the elbow, dividing the lacertus fibrosus ( Fig. 72.8C ) and any remaining parts of the flexor muscle origin.
- ▪
If a flexion contracture of the elbow persists, incise the fascia of the brachialis muscle. Then transplant the ulnar nerve anterior to the epicondyle. Now the muscle mass has been displaced 3 to 4 cm distal to its original location.
- ▪
Close the wound and apply a cast or plaster splints to hold the forearm in supination and the wrist and fingers in neutral positions.
Postoperative Care
At 3 weeks, the cast or splints and the sutures are removed. An extension hand splint is applied, which is worn constantly for 3 months and then only at night for 3 more months or, in children, until growth is complete.
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