Stability of myelomeningocele spines treated with the mayfield two-stage anterior and posterior fusion technique.
METHODS
Retrospective review of the results of operative treatment for paralytic thoracolumbar lordoscoliosis in six consecutive myelomeningocele patients treated with the Mayfield two-stage combined anterior and posterior fusion and instrumentation technique.


OBJECTIVE
To assess the long-term stability of myelomeningocele spines treated with the Mayfield technique.


BACKGROUND
An initial description of the technique by Mayfield and an early study of the evolution of the two-stage combined anterior and posterior instrumented fusion of paralytic lordoscoliosis in myelomeningocele spines are available.


METHODS
Study of the six individual patients showed that the mean age at the time of surgery was 13 years and 8 months (range, 9 years 9 months to 15 years 10 months). At the time of surgery, the major lumbosacral curve averaged 81 degrees (range, 52-137 degrees ), pelvic obliquity was 28 degrees (range, 1-48 degrees ), torso decompensation was 2.8 cm (range, 0-6.0 cm), thoracic kyphosis was 60 degrees (range, 25-93 degrees ), lumbar lordosis was 106 degrees (range, 55-151 degrees ), and sacral anteflexion was 78 degrees (range, 22-117 degrees ). The mean duration of follow-up evaluation was 13 years 5 months (range, 8 years 10 months to 16 years 11 months).


RESULTS
Clinical and radiographic evaluation showed that immediately after surgery, the lumbosacral curve was corrected to an average of 25 degrees and at last follow-up evaluation was 25 degrees, for a final correction of 69%. Pelvic obliquity was corrected to 7 degrees, 5 degrees at last follow-up evaluation, for a 82% correction. Torso decompensation was corrected to 1.4 cm initially and finally to 0.3 cm, for an 89% correction. Kyphosis was corrected to 52 degrees, finally to 50 degrees (17% decrease); lordosis to 73 degrees and finally to 67 degrees (37 degrees decrease); and sacral anteflexion corrected to 51 degrees and finally to 56 degrees (28% decrease). In one patient, the tip of the longest rod displaced from the uppermost hook and was replaced with maintenance of correction. Another patient had dehiscence of the pelvic portion of the posterior wound, with secondary bacterial contamination, and healed by secondary intention.


CONCLUSIONS
The Mayfield technique effectively corrected and stabilized these difficult myelomeningocele spinal deformities, using distraction against square-holed hooks seated on the sacral alae, which contain the best-quality bone in these hypoplastic pelves.
Osebold
W R
WR
Shriners Hospital, Spokane, Washington 99210-2472, USA.
D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008141:Lordosis / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008591:Meningomyelocele / Q000000981:diagnostic imaging / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome