Orthopedic Teaching Cases 2023, Jan, 18 | 12:00 am

Pediatric orthopedic cases 37

CASE                               37                               

 

A 4-year-old male with cerebral palsy is brought to your clinic for evaluation. He is

nonambulatory but is able to hold his head up against gravity. He can sit on the floor with assistance. He can help stand for transfers but does not take any steps.

As part of his assessment, you document his GMFCS level as:

  1. GMFCS I

  2. GMFCS II

  3. GMFCS III

  4. GMFCS IV

  5. GMFCS V

  6. Not enough information provided to classify

 

Discussion

The correct answer is (D). The Gross Motor Function Classification System (GMFCS) is an ordinal grading system used to describe the gross motor function of children with cerebral palsy. This child is nonambulatory, but does have head control and is able to participate with transfers which classifies him at a level 4. A thorough description of GMFCS classification can be found at http://motorgrowth.canchild.ca/en/GMFCS/resources/GMFCS-ER.pdf. A brief summary of Palisano et al.’s work is as follows:

LEVEL I—Walks without limitations. They can run and jump, but speed and coordination are limited.

LEVEL II—Have some limitations in walking long distances and with balance. Need a railing for going up and down stairs. May use wheeled mobility devices when traveling longer distances. Have more difficulty with running and jumping than level 1 children. After age 4 can often walk without a handheld mobility device.

LEVEL III—Walk using a handheld mobility device to walk indoors. Often will use a wheelchair when outside. Are able to sit on their own either with no, or very little, support. They can be independent for standing transfers.

LEVEL IV—Need a manual or powered wheelchair, can sit upright with assistance.

LEVEL V—Have severe limitations in head and trunk control, they are transported in a manual wheelchair and require extensive assistance.

The parents report that they recently moved to the area and are hoping to establish care with you for the orthopaedic care of their child. They note that he has a history of botox injections that were “helpful,” but they have noticed that his hips are “more tight” now than they were previously.

What is the mechanism by which botox works?

  1. Inhibits the release of calcium into the sarcoplasmic reticulum

  2. Inhibits the release of acetylcholine at the neuromuscular junction

  3. Promotes binding of GABA to GABA type A receptors

  4. Binds to a synaptic vesicle glycoprotein and inhibits presynaptic calcium channels

  5. Functions as a gamma-aminobutyric acid (GABA) analog that inhibits calcium influx into presynaptic terminals and suppresses the release of excitatory neurotransmitters

Discussion

The correct answer is (B). A is the mechanism of dantrolene. C is the mechanism of benzodiazepenes. D is the mechanism of levetiracetam (Keppra). E is the mechanism of action for baclofen.

On examination, his hip abduction is less than 30 degrees and his migration index is 35%. What do you recommend?

  1. Continued observation

  2. Nighttime hip abduction bracing

  3. Physical therapy

  4. Surgery—soft tissue releases

  5. Surgery—soft tissue releases and pelvic osteotomy

 

Discussion

The best answer is “D.” Soft tissue lengthenings are indicated for children who are less than 8 years of age, who have hip abduction less than 30 degrees, and have a migration index greater than 25% but less than 60%. For patients with a migration index greater than 60%, bony reconstruction is indicated. This 4-year-old child’s MI is only 35% therefore bony work is not pursued at this time. High success rates have been seen with soft tissue lengthenings alone for children with migration index less than 40%. Choice B is incorrect because hip abduction bracing has not been found to prevent hip dislocation. A and C would be correct if the child’s abduction was greater than 45 degrees and the MI was less than 25%—if the abduction is less and the MI is higher, the hip is at risk. Once abduction is less than 30 degrees and the MI is over 25%, surgical intervention is considered.

The patient does well after surgery with no immediate postoperative complications. He continues in a physical therapy program and his parents are very

attentive to a home exercise program. They move away for a few years but return to your care at age 8. On examination you note limited ROM of the right hip and the parents report that he now seems more uncomfortable with transfers and sitting. You order an AP pelvis x-ray (Fig. 10–60).

 

 

 

Figure 10–60

 

What is your current recommendation of treatment for this new presentation?

  1. Observation

  2. Botox and bracing

  3. Soft tissue lengthenings (revision)

  4. Pelvic osteotomy

  5. Varus derotation osteotomy of the femur with possible shortening, soft tissue lengthenings, acetabuloplasty

Discussion

The correct answer is (E). Since the patient is older than 4 years of age, has a migration index greater than 40%, and does not have evidence of advanced degenerative changes of the femoral head, hip reconstruction is recommended. Choices A, B, and C will not help a child with a dislocation/severe subluxation. A pelvic osteotomy alone would likely not be enough to reduce and stabilize this hip given the significant coxa valga. There is increasing support for combined procedures that address both the proximal femoral deformity as well as the

insufficiency of the acetabular coverage.

 

Objectives: Did you learn...?

 

The GMFCS classification of children with cerebral palsy?

 

The mechanism of action of Botox—an agent frequently used in the soft tissue management of children with cerebral palsy?

 

Considerations and indications for surgery in children with cerebral palsy depending on both clinical and radiographic measures?