Spastic Dysfunction of the Elbow

Diagnosis

CP is most commonly diagnosed at around 1 year of age because of delayed development of normal pinch motor milestones. Normal children develop two-handed activity and bilateral grasp and progress from two-handed manipulation of objects to one-handed manipulation at the age of 18 to 24 months. Early hand dominance is often a presenting sign in children with CP. In this scenario, a complete neurologic evaluation is necessary, including evaluation of their lower extremities, before a diagnosis of CP can be made.

CP is a disorder of the CNS that manifests itself in peripheral motor dysfunction and joint malpositioning. In spastic hemiplegia due to CP, the most common peripheral manifestations in the upper limb are shoulder internal rotation, elbow flexion, forearm pronation, wrist flexion/ulnar deviation, finger clenching (flexor spasticity), swan-necking, and thumb-in-palm deformity, as shown in Fig. 118.1 . Increased muscle spasticity causes muscle imbalance across joints, which initially leads to impaired function and eventually causes joint contractures with skeletal deformity. The typical elbow deformity of CP is elbow flexion and forearm pronation. Occasionally, it results in posterior dislocation of the radial head, which requires no treatment unless in adult life it results in a painful bursa; then the radial head may be excised. Flexion-supination contractures of the elbow can occur but are uncommon in CP.

Clinical Assessment

Assessment of the patient with spastic CP starts with the history and physical examination. Because CP is associated with low birth weight and prematurity, associated medical problems should be noted, particularly seizures and mental retardation, that are indicators of more global CNS involvement.

Physical examination includes assessment of passive range of motion, active range of motion, muscle tone/control, and overall function of the limb (including hand function assessment). The limb is first examined for passive range of motion of the shoulder, elbow, forearm, wrist, and hand, evaluating the limb for joint and muscle contractures. Even if only the elbow is to be treated, the shoulder, forearm, wrist, and hand need to be assessed because they are essential for the individual to effectively use the limb. Muscle tone is noted through the passive evaluation of joint mobility. Passive range-of-motion exercise needs to be done slowly to overcome muscle spasticity with gentle sustained resistance. Assessment for muscle and joint contracture by passive mobility of the joint and passive stretch of the muscle is performed. The tightness and contracture of some of the muscles around the elbow can be easily palpated, particularly the biceps, brachialis, brachioradialis, and pronator teres.

Active range of motion is assessed next, including specific muscle testing for voluntary motor control, particularly of elbow flexion/extension as well as pronation/supination. Overall use of the upper extremity should be characterized both from the history obtained from the parents and by direct physician observation. The dynamic positioning of the shoulder, elbow, forearm, wrist, fingers, and thumb is noted, particularly for grasp and release, as well as pinch function. Age-appropriate tasks or toys that require two-handed use are helpful in this assessment.

Definition of Goals

Impairment of function for the child with CP is different from that for normal developing children. First, for children with CP, gait is also affected. Recent studies have pointed out that arm swing is an integral part of gait. Significant contractures of the elbow can play a role in abnormal gait and contribute to compensatory measures with hemiplegic gait dysfunction. Second, healthcare providers should take into account the mental health of their patients with CP when making decisions about interventions. Although movement deviations in the upper and lower extremities often occur simultaneously in patients with unilateral CP, it is the upper extremity deviations and not the lower extremity deviations that correlate best with lower self-esteem. Even in highly functioning individuals with mild CP, self-esteem may be adversely affected by such deviations. Elbow flexion is the main contributor to arm posturing deviations (compared with shoulder flexion, shoulder abduction, and wrist flexion). As such, correction of this particular anomaly could be of benefit for the child's development of improved self-esteem. Third, functional tasks are more difficult in children with CP because of the other concomitant impairments. Functional tasks that should be tested in every child are dressing, toileting, feeding, two-handed assisted work, grasp and release, and pinch.

The functional goals for the limb should be established so that it can be determined whether the anticipated function is being accomplished by the patient. The goals of elbow surgery are different for a highly functioning hemiplegic patient versus a lower-functioning quadriplegic patient. In a higher-functioning child, common goals of elbow surgery include greater arm swing with gait, improved positioning of the hand in space, and improved cosmesis. For the lower-functioning child or adolescent patient, common goals are decreased elbow contracture for better joint positioning and better hygiene.

In the past, sensory deficiencies of the hand were believed to be a contraindication to surgery in CP. If tested carefully, sensory deficiencies are present in nearly all children with CP. Several studies have shown that impaired sensation is not a contraindication to surgical intervention in the patient with CP.

Appropriate consultation or a multispecialty approach to care should be considered before surgical intervention is considered. Several alternatives to surgical intervention exist and should be considered. Exploration of the treatment pros and cons may require discussions that include the rehabilitation physicians, neurologists, and neurosurgeons to adequately explore the options of tone-reducing medications (diazepam, baclofen), tone-reducing injections (botulinum toxin, phenol), tone-reducing neurosurgery interventions (selective dorsal rhizotomy), or therapy interventions (splinting, stretching programs). At many institutions a spasticity management team of specialists is involved in patient evaluation for tone-reducing interventions that helps guide the orthopedic surgeon as to other treatment alternatives.