The crankshaft phenomenon after posterior spinal arthrodesis for congenital scoliosis: a review of 54 patients.
METHODS
Retrospective chart and radiographic reviews were conducted.


OBJECTIVE
To identify the incidence of and any possible risk factors for the crankshaft phenomenon after posterior spinal arthrodesis for congenital scoliosis.


BACKGROUND
Studies have shown the crankshaft problem to be common after posterior arthrodesis for infantile and juvenile idiopathic scoliosis, but the few reports available show it to be much less common for congenital scoliosis.


METHODS
This study chose children fused before the pubertal growth spurt, all classified as Risser 0 and with open triradiate cartilages. These children were followed to the end of their growth (mean follow-up period 12 years). Several measurement parameters were used for evaluation.


RESULTS
The crankshaft problem, measured as a Cobb angle increase of more than 10 degrees, was seen in 15% of the 54 patients. There was a positive correlation with earlier surgery and larger (>50 degrees) curves. No other positive correlations could be identified.


CONCLUSIONS
Crankshafting was observed in 15% of the patients, more often with larger curves and earlier fusions.
Kesling
Kimberly L
KL
United States Army, El Paso, Texas, USA.
Lonstein
John E
JE
Denis
Francis
F
Perra
Joseph H
JH
Schwender
James D
JD
Transfeldt
Ensor E
EE
Winter
Robert B
RB
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011627:Puberty; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D012600:Scoliosis / Q000151:congenital* / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects*; D016896:Treatment Outcome