Introduction

Cerebral palsy is often related to hypoxic ischemic encephalopathy (HIE) when the infant’s brain is deprived of adequate blood flow secondary to a hypoxic-ischemic event during the prenatal, intrapartum, or postnatal period. HIE requires immediate intervention and affects 20 out of every 1000 full term births. The incidence rate in premature babies is 60% of all live births. HIE caused by asphyxia is the leading cause of infant fatalities in the United States, as well as the primary source of severe impairments. Effects of HIE may include developmental delays, epilepsy, cognitive issues, motor skill delays, and neurodevelopment delays. The true severity of HIE generally cannot be determined until the baby reaches 3–4 years old. The end-result is cerebral palsy with varying signs and symptoms.

There are a number of different causes of HIE that can occur before, during, or after the baby is born. HIE pregnancy risks included maternal diabetes with vascular disease, decreased placental circulation, preeclampsia, cardiac disease, infections of the fetus, drug and alcohol abuse, severe fetal anemia, and lung malformations. HIE birth risks include excessive bleeding from the placenta, low maternal blood pressure, umbilical cord rupture, prolonged late stages of labor, abnormal fetal position, and rupture of the placenta or the uterus. Postpartum period risks include premature babies, severe cardiac or pulmonary disease, infections (sepsis and meningitis), low neonatal blood pressure, brain or skull trauma, and congenital brain malformations.

The orthopedic team is usually consulted when the child fails to reach certain developmental milestones, such as sitting, crawling, or walking. At our center, a team approach is utilized with input from the surgeons and therapists that care for the upper and lower extremities. In addition, a physiatrist with exceptional knowledge is an integral part of our team. Neurologists are relegated to consultants on difficult cases with questionable signs and symptoms or progressive neurologic changes.

Classification

The classification of cerebral palsy denotes the number of limbs involved and the type of spasticity. The classic hemiplegic cerebral palsy child has involvement of one side (arm and leg) with sparing of the other side. The quadriplegic cerebral palsy child has involvement of all four limbs, although the severity may vary. The type of spasticity is either spastic, athetoid, or a combination of spastic and athetoid. Spasticity results from dysregulated reflex arc messaging from the damaged upper motor neurons. We explain this phenomenon to families as the muscles always want to “run” and the intact brain dampens this response. A damaged brain loses this ability and cannot suppress the muscles from moving. Concomitant extrapyramidal involvement causing additional movement disorders, primarily athetosis, which is a rhythmic uncontrollable twisting movement pattern. In addition, to these spastic movement patterns, the limb or portions of the limb may be flaccid without any volitional movement. Various tones results in muscle imbalance across limb segments, which leads to abnormal upper limb position, contracture formation, and hampered function.

Assessment

The assessment of the child requires input from all team members. In our clinic, the physiatrist manages the spasticity with medications, pumps, and/or botulinum toxin injections. The upper extremity surgeons and occupational therapists treat the arms. The lower extremity surgeons and physical therapists manage the legs. The spine surgeons monitor for spinal deformities, such as scoliosis. The spine surgeons also perform procedures directed at decreasing spasticity, such as the DREZ (human dorsal root entry zone) procedure. This team approach provides optimum case as long as there is communication among the teams to avoid fragmentation of care.

The upper extremity evaluation varies with the patient’s age, developmental stage, and cognitive function. Early therapy is the mainstay of treatment in infants. Establishing access for the child and family to therapy and support resources is mandatory. The parents require time, patience, and support to comprehend their child’s diagnosis. This process takes time and early surgical intervention is avoided and rarely necessary. Over time, the upper extremity team develops a rapport with the child and family that will ease subsequent decision-making. There is no “quick fix” for cerebral palsy and the family will endure lifelong trials and tribulations. Understanding this monumental effect on the family will enhance the doctor–therapist–family relationship. The physicians and therapist must express the necessary amount of empathy and compassion while avoiding overt expressions of sympathy.

The assessment should include the legacy measures of range of motion and strength. Any joint contracture should be documented. Sensibility tools vary with the age of the child and are discussed in Chapter 3 . In addition to legacy measures, a patient reported outcome (PRO) measure (patient and/or parent) should also be performed. The various PROs are covered in Chapter 4 and often shed light into the expectations of the parent and/or child. A set of documented individualized treatment goals is invaluable to prevent unrealistic exceptions from surgery.

Videotape or functional evaluation of the patient performing routine activities or scored functional tests (Jebsen-Taylor, Box and Blocks, Pegboard) can mimic functional loss compared to a clinical visit. Validated evaluation tools, such as the Shriners Hospital for Children Upper Extremity Evaluation, upper extremity cerebral palsy, and Assisting Hand Assessment, can help define upper extremity disability and deformity and guide treatment. In reality, we rarely use videotaping in our clinical practice, but rather rely on clinical acumen and repeated examinations.

Surgical Indications/Methods

Surgery of the upper extremity in cerebral palsy is reparative and often palliative, but not curative. Surgery can improve the functional limb; however, no operation will not restore normal function to the impaired limb. We discriminate between functional and nonfunctional limbs that have overwhelming spasticity and minimal volitional movement. Hence, there are different indications and procedures based upon the baseline function of the limb. In general, tendon lengthenings and tendon transfers are performed on functional limbs. Tenotomies, myotomies, and fusions are performed on nonfunctional limbs to improve their position and allow hygiene. However, tenotomies, myotomies, and fusions may also be applicable to functional limbs. In addition, nerve surgery for spasticity treatment via nerve stripping or isolated motor neurectomy can be performed.

A muscle–tendon unit can be lengthened using one of three methods ( Fig. 14.1 ). The first method is a Z-plasty of the tendon and suturing the cut ends together in an elongated state. A second method is fractional lengthening whereby the muscle–tendon junction is identified. The tendon is isolated along its origin from the muscle. A tendinous segment is identified that has muscle on both sides of the tendon. The tendon is incised leaving the muscle intact on both sides of the cut. The respective part (e.g., elbow or wrist) is stretched elongating the cut ends of the tendon within the substance of the muscle. No suturing is required. The third method involves releasing the origin of the muscle and allowing it to slide in a distal direction during stretching of the limb.

A muscle–tendon unit can be lengthened using one of three methods. (A) Z-plasty lengthening of biceps’ tendon. (B) Fractional lengthening of the brachialis muscle–tendon junction. (C) Muscle slide of the flexor pronator origin.

Courtesy of Shriners Hospital for Children, Philadelphia.

The particular lengthening technique utilized depends on numerous factors including the anatomy of the muscle–tendon unit, the length required, and the surgeon preference. For example, there are certain muscles that have short muscle–tendon units (e.g., biceps muscle) and are not amenable to fractional lengthening. In addition, if substantial lengthening is required, fractional lengthening would exceed the length of the muscle–tendon junction resulting is discontinuity between the muscle and tendon. Lastly, certain muscles are amendable to release of the origin and allowing the muscles to slide in a distal direction (e.g., flexor pronator mass and thenar muscles).

Release of a muscle or tendon can be performed via tenotomy or myotomy. The method selected also varies with the muscle–tendon anatomy and the surgeon preference. For example, the brachioradialis originates from the supracondylar ridge of the humerus and inserts along the forearm fascia culminating in its attachment to the radial styloid. Simply cutting the tendon at the radial styloid will not negate its ability to flexion the elbow. Hence, myotomy is necessary to eliminate its effect on elbow flexion. In contrast, the flexor carpi radialis has a long tendon that is receptive to tenotomy.

Hierarchy of Upper Limb Function

Proximal muscle stability and control is mandatory for hand function. The shoulder must be stable allowing the arm and forearm to function. Surgery to enhance shoulder motion for cerebral palsy has been disappointing. In contrast to brachial plexus injuries, the muscles are spastic and poor candidates for transfer. Surgery is directed toward lessening the myostatic contracture to allow more supple movement. With reference to the elbow, flexor spasticity is commonplace. In mild hemiparesis, this yields elbow flexion posturing during walking and times of excitement. In more severe cases, a myostatic contracture develops that limits elbow extension. Lengthening and myotomies can lessen the elbow flexion tone. The forearm should not be forgotten and is a frequent source of discontentment. The common forearm position is spastic protonation that is initially supple (dynamic) and develops a myostatic contracture over time. Excessive protonation impedes supinations activities, such as feeding, carrying a tray, obtaining soap from a dispenser, catching a ball, and wiping one’s buttocks.

The management of the wrist and hand in cerebral palsy follows the concepts of “hierarchy of hand function” or the “reconstruction ladder” ( Table 14.1 ). The primary fundamental movement is wrist extension, which yields tenodesis for grip as the fingers flex into the palm and tenodesis for lateral pinch as the thumb adducts against the index finger. Wrist extension also aligns the finger flexors along Blix’s length–tension curve for maximum active grip. The second most essential movement is lateral pinch, which is necessary to perform numerous activities of daily living. Most daily activities are accomplished with lateral pinch, such as holding an object, turning a key, or using a fork. The third essential motion is grasp, which allows the holding of objects. The fourth and last movement is digital opening for object acquisition. The reason to place this function lowest on the ladder is that wrist flexion yields passive digital opening, which is often adequate for object procurement. In addition, synchronous digital opening is difficult to achieve via surgery as metacarpophalangeal joint extension is mainly an extrinsic function (extensor digitorum communis, extensor indicis proprius, and extensor digiti quinti) and interphalangeal joint extension is primarily an intrinsic function (interossei and lumbricals).

Shoulder Reconstruction