Dual growing rod technique for the treatment of progressive early-onset scoliosi

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Spine. 2005 Sep 1;30(17 Suppl):S46-57.

Dual growing rod technique for the treatment of progressive early-

onset scoliosis: a multicenter study.

Akbarnia BA, Marks DS, Boachie-Adjei O, AG, Asher MA.

University of California, San Diego, San Diego Center for Spinal

Disorders, La Jolla, CA, USA.

STUDY DESIGN: A retrospective case review of children treated with

dual growing rod technique at our institutions. Patients included had

no previous surgery and a minimum of 2 years follow-up from initial

surgery. OBJECTIVES: To determine the safety and effectiveness of the

previously described dual growing rod technique in achieving and

maintaining scoliosis correction while allowing spinal growth.

SUMMARY OF BACKGROUND DATA: Historically, the growing rod techniques

have used a single rod and the reported results have been variable.

There has been no published study exclusively on the results of dual

growing rod technique for early-onset scoliosis. METHODS: From 1993

to 2001, 23 patients underwent dual growing rod procedures using

pediatric Isola instrumentation and tandem connectors. Diagnoses

included infantile and juvenile idiopathic scoliosis, congenital,

neuromuscular, and other etiologies. All had curve progression over

10 degrees following unsuccessful bracing or casting. Of 189 total

procedures within the treatment period, 151 were lengthenings with an

average of 6.6 lengthenings per patient. Analysis included age at

initial surgery and final fusion (if applicable), number and

frequency of lengthenings, and complications. Radiographic evaluation

included measured changes in scoliosis Cobb angle, kyphosis,

lordosis, frontal and sagittal balance, length of T1-S1 and

instrumentation over the treatment period, and space available for

lung ratio.

RESULTS: The mean scoliosis improved from 82 degrees (range, 50

degrees-130 degrees) to 38 degrees (range, 13 degrees-66 degrees)

after initial surgery and was 36 degrees (range, 4 degrees-53

degrees) at the last follow-up or post-final fusion. T1-S1 length

increased from 23.01 (range, 13.80-31.20) to 28.00 cm (range, 19.50-

35.50) after initial surgery and to 32.65 cm (range, 25.60-41.00) at

last follow-up or post-final fusion with an average T1-S1 length

increase of 1.21 cm per year (range, 0.13-2.59). Seven patients

reached final fusion. The space available for lung ratio in patients

with thoracic curves improved from 0.87 (range, 0.7-1.1) to 1.0

(range, 0.79-1.23, P = 0.01). During the treatment period,

complications occurred in 11 of the 23 patients (48%), and they had a

total of 13 complications. Four of these patients (17%) had unplanned

procedures. Following final fusion, 2 patients required extensions of

their fusions because of curve progression and lumbosacral pain.

CONCLUSION: The dual growing rod technique is safe and effective. It

maintains correction obtained at initial surgery while allowing

spinal growth to continue. It provides adequate stability, increases

the duration of treatment period, and has an acceptable rate of

complication compared with previous reports using the single rod

technique.