ORTHOPEDIC PROCEDURES

General information

Orthopedic surgery has played an important role in the development of the treatment of spasticity. The development of aseptic technique and more reliable anesthesia allowed expansion of surgical options to more complex procedures, including neurectomies, fasciotomies, osteotomies, and arthrodeses. It is stressed the importance of careful preoperative assessments, selection of appropriate operative procedures, and extensive and prolonged postoperative care.

GOALS OF SURGICAL TREATMENT

The goals of orthopedic surgery in both cerebral palsy and acquired spasticity are to increase mobility, decrease the use of external aids, correct or prevent deformity and ultimately maximize function. Chronic spasticity may lead to fixed soft tissue or bony deformities. When these do not respond to conservative measures such as manual stretch and serial casting, and are of functional significance to the patient, surgical treatment is warranted. Surgery also has a role in the treatment of spasticity in the absence of fixed deformity. A neurectomy can decrease spasticity through interruption of the reflex arc. Procedures that separate the spastic muscle from its insertion or lengthen its tendon can eliminate its action on the limb or reduce its mechanical advantage. Furthermore, such procedures may, by reducing the stretch on the muscle, decrease the spindle afferent impulses and the resulting spasticity. The specific techniques include tendon lengthening, tendon transfer, neurectomy, osteotomy, resection arthroplasty, and arthrodeses. Joint realignment (osteotomy) and resection or fusion (arthrodeses) is required when joint or bony deformity has developed. Tendon lengthening is used to rebalance agonist-antagonist muscle groups, or correct musculotendinous unit contractures. Tendon transfers have limited indications because of the difficulty in assessing the strength and volitional control of spastic muscles. The joint that is be mobilized by the tendon transfer should have a full passive range of motion preoperatively to maximize the success of the procedure. Neurectomies are mostly limited to the hip (anterior obturator neurectomy) or nonfunctional limbs because an irreparable lesion is created.

SURGICAL CRITERIA

The following guidelines maximize the benefit from surgery.

  1. For procedures requiring active therapy postoperatively, the patient should be developmentally or cognitively at a level to allow adequate cooperation.
  2. For procedures intended to improve gait, the patient should demonstrate enough trunk control to stand with minimal assistance. Deformities alone do not usually prevent walking.
  3. Compliance with a preoperative program of exercises and night splinting minimizes the chance of recurrence. 
  4. A stable supportive home or institutional setting should be present to ensure proper postoperative care and follow-up


PATIENT POPULATION

Although most commonly used with children with CP, the procedures can be applied to children and adult with acquired spasticity as well. The specific cause of the CNS pathology is not often directly relevant to the selection of treatment. The cause, however, may be informative about a number of issues that play a role in treatment planning: 
  1. Is the CNS pathology static / progressive? The answer will clarify the functional prognosis both with and without intervention, and assist in the appropriate timing of surgery. 
  2. Is the patient developmentally or cognitively able to cooperate and participate in pre- and postoperative treatment regimens? 
  3. Are developmental changes to be expected that may influence the success and timing of surgery? (Examples are bone growth and maturation of the hip joint.)
PROCEDURES FOR THE FOOT AND ANKLE

Although the positions of the trunk, hips, knees, and feet influence each other in gait and stance, deformities at each level are more effectively reviewed separately.

The most common problems at the feet and ankle are equinus, calcaneus, valgus, varus, cavus, and hallux valgus, and toe deformities.

ROCEDURES FOR THE KNEE

Flexion is the most common deformity seen in the spastic knee, although hyperextension, patella Alta, and chondromalacia can also occur.

PROCEDURES FOR THE HIP

Problems relating to spasticity of muscles acting on the hip joint have been the subject of many studies in the last decade. The distribution and severity of the spasticity determine the deformity. In cerebral palsy, hemiplegic patients in frequently have hip deformity except for increased femoral ante version. Flexion, adduction, and internal rotation abnormalities are frequently seen in spastic diplegia and may interfere with gait efficiency and progress to subluxation or, rarely, dislocation. Soft tissue contractures of the hip adductors and flexors are frequent in patients with quadriplegia, and commonly produce hip dislocation, affecting sitting balance.

PROCEDURES FOR THE SPINE

  • Scoliosis
  • Kyphosis
  • Lordosis
PROCEDURES FOR THE UPPER EXTREMITY

Thumb in palm wrist and finger flexion, elbow flexion and pronation, and shoulder adduction and internal rotation are the most common deformities seen in the spastic upper extremity. Successful surgical intervention requires more precise evaluation and goal definition than in the lower extremity because of the role played by sensibility and intellectual function in the skilled use of the upper extremity. Because there are no surgical procedures to restore sensation, expectations from surgery must be limited in cases of sensory impairment. Realistic goals include improving grasp, release, and pinch, facilitating the use of the hand for gross assistance and improving appearance. In cerebral palsy patients, surgery should not be done before the central nervous system has matured sufficiently to permit accurate evaluation, and cooperation with post-operative therapy. Similarly, in patients with acquired spasticity, surgery should be considered only after maximal recovery has occurred. An exception to this would be severe pronators spasticity that threatens to produce posterior radial head dislocation.

Several hand patterns can be defined that are useful in determining appropriate surgery. The hand that has adequate grasp, release, and pinch but lacks dexterity and speed will not be helped by operative intervention. If the wrist must be flexed to extend the fingers, surgery may improve function. If the fingers cannot actively be extended, even with the wrist flexed, cosmetic improvement only is the most realistic goal. In addition to observation of deformity patterns, specific functions should be evaluated, including stereo gnosis, hand placement, strength, general intelligence, and motivation. Within limits motivation may be as important as intelligence. Dynamic electromyography can be helpful in determining whether muscles are phasic or fire continuously. The ideal muscle for transfer rates "good" in strength, is under voluntary control, and is phasic with the activity for which it is transferred.

  • Thumb-in-palm
  • Wrist flexion
  • Elbow flexion
  • Forearm pronation
  • Shoulder flexion and internal rotation
SUMMARY

Surgery can be an effective way to maximize function and simplify care in patients with spasticity. Accurate preoperative assessment and a well supervised postoperative program are critical in achieving these goals. To optimize surgical results, the assessment must be in the context of the patient's overall functional goals. The likelihood of further growth, recovery, or deterioration will shape plans for surgical intervention, as will the patient's prognosis for achieving important functional goals, both with and without surgery. In addition, the patient's history of prior conservative treatment will affect the level of surgical aggressiveness chosen.

© Institute of Child Development