✓ Selective dorsal rhizotomy is increasingly used for management of spastic quadriplegic cerebral palsy but rates of hip stability following the operation have not been reported. Determining hip stability by radiographic measurement of lateral migration of the femoral head beyond a lateral edge of the acetabulum after dorsal rhizotomy allows an objective assessment of the outcome of the operation. This prospective study examined the effect of selective dorsal rhizotomy on lateral migration of the femoral head in 45 children with spastic quadriplegic cerebral palsy. The children ranged in age from 2 to 9 years (average 5 years 1 month) and were grouped according to their ages with 23 children in the 2- to 4-year-old group and 22 children in the 5- to 9-year-old group. Postoperative follow up ranged from 7 to 50 months (average 20 months). The Reimers migration percentage (MP), a measure of the lateral migration of the femoral head, was calculated from anteroposterior hip radiographs taken prior to the operation and at the last follow-up examination. Of the 90 hips involved, 9% improved, 80% remained unchanged, and 11% worsened, yielding a radiographic stability rate of 89%. The hips with postrhizotomy worsening of the MP had an average preoperative MP of 14% (range 9% to 38%) and an average postoperative increase in MP of 18% (range 11% to 37%). Of the 45 children, four subsequently underwent unilateral derotational femoral osteotomies for persistent or worsening hip subluxation. There was a significant tendency for the MP to worsen in patients with lower prerhizotomy MP values (χ2 = 20.74, df = 4, p = 0.001), but the age of patients and their ambulatory status at the time of rhizotomy had no bearing on postoperative hip stability. The data indicate that selective dorsal rhizotomy prevents progressive lateral migration of the femoral head in the majority of children who undergo the operation for spastic quadriplegia.
Robert C. Heim, T. S. Park, George P. Vogler, Bruce A. Kaufman, Michael J. Noetzel and Madeleine R. Ortman
Paul C. Francel, Myles Koby, T. S. Park, Benjamin C. P. Lee, Michael J. Noetzel, Susan E. Mackinnon, Martin M. Henegar and Bruce A. Kaufman
✓ Neurosurgical management of birth-related brachial plexus palsy involves observing the patient for a period of several months. Operative intervention is usually undertaken at 3 to 6 months of age or more in infants who have shown little or no improvement in affected muscle groups. Ancillary tests such as electromyography and nerve conduction studies are occasionally useful. No radiological study has been consistently helpful in operative planning, except for contrast computerized tomography (CT) myelography, which requires general anesthesia in infants. This is because the infant's small size exceeds the functional resolution of the imaging modalities.
This report describes the use of a special sequence of magnetic resonance (MR) imaging entitled “fast spin echo” (FSE-MR). Unlike CT myelography, this technique provides high-speed noninvasive imaging that allows clinicians to evaluate preganglionic nerve root injuries without the use of general anesthesia and lumbar puncture. The utility of this technique is illustrated in three cases, two involving either infraclavicular exploration or a combination of infraclavicular and supraclavicular exposure based on FSE-MR findings. The FSE-MR imaging offers an excellent alternative to contrast CT myelography in evaluation of infants with birth-related brachial plexus injuries.