The study of vertebral growth effected by growing rod in congenital scoliosis patients

English Keywords:Congenital scoliosis  Growing rod  Vertebral growth

English Abstract:

  【Abstract】 Objectives: To observe the vertebral growth effected by growing rod techniques in congenital scoliosis patients. Methods: 221 patients with congenital scoliosis who underwent growing rod surgery from June 2008 to December 2013 were documented. 31 cases had spine CT for at least 2 times scan before and after a re-lengthening surgery. The first surgery was performed at 3.2 to 9.1 years old. The first CT scan was performed at 7.1±2.3 years old. The last CT scan was at 10.0±2.1 years old. 92 re-lengthening operations were performed during 1.0-5.9 years. The re-lengthening rate was 3 times per person or 1.1 times per year. When patients had the first CT scan, they had average of 2 re-lengthening operations. When patients had the last CT scan, they had an average of 5 re-lengthening operations. Several parameters were documented including age, Cobb angle of main curve, lateral thoracic kyphosis Cobb angle, T1-T12 height, T1-S1 height and trunk shift. Results: The first and last CT scan showed the height of vertebra inside instrument was 18.2±4.7mm, 21.8±5.5mm respectively; and the height of vertebra outside instrument was 19.2±3.2mm, 22.7±3.4mm respectively. There was a significant difference between the height changes(P=0.035). The growth rate of vertebrae inside instruments was 0.2mm/yr faster than that vertebra outside instruments(1.4±0.9mm/yr vs 1.2±0.9mm/yr). The Cobb angle of main curve was 56.8°±15.3° and 52.9°±15.4° respectively, the thoracic kyphosis was 36.6°±18.9° and 43.7°±18.2° respectively, the T1-T12 height was 16.7±3.3cm and 19.1±3.3cm, and the T1-S1 height was 27.9±4.7cm and 32.5±4.7cm. There was a significant difference between each pair of parameters(P<0.05). The trunk shift was 18.6±15.2mm and 20.0±21.4mm, and there was no difference(P>0.05). Conclusions: The growing rod technique has a positive effect on the growth rate of the vertebra inside the instruments, which promotes the spine growth.