Time Interval Between Lengthening Of Growing Rods Can Influence Its Effectiveness In The Treatment Of Early Onset Scoliosis

Objective. To investigate the influence of different time intervals between lengthening on the effectiveness of growing rod in the treatment of early onset scoliosis.Methods. A retrospective study of patients undergoing GR treatment in our hospital from July 2002 to February 2014 was undertaken. We defined a lengthening at a 12-month interval as a research event in group A, and two continuous lengthening at 6-month intervals as a research event in group B. Therapeutic outcomes at the end of the events were compared between the two groups. The impact of different factors on therapeutic outcomes were analyzed using multiple linear regression. Independent samples T-test and covariance were used to confirm the findings.Results. Multiple linear regression showed that different time interval between lengthening was the only factor of improvement of T1-S1 length and sitting height. In addition, both the preoperative cobb angle (starting point) and gender could affect changes in the cobb angle and standing height.(P=0). Further analysis by ANCOVA and independent samples T-test showed that the cobb angle change in group A was 12.04° ±1.08°, the Ti-Si increased by 1.05±0.72cm, the sitting height increased by 2.52 ±1.40cm, and the standing height increased by 5.64±1.84cm. In group B, the change in cobb angle was 23.49°±1.16,T1-S1 increased by 1.97±0.88cm, sitting height increased by 3.84±1.82cm, and standing height increased by 7.72± 2.99cm. A total of 10 implant-related complications occurred in group A, whereas no implant-related complications occurred in group B.The difference between group A and group B was statistically significant (P<0.05).Conclusion. There was greater growth and correction, as well as less complications, in those lengthened at 6 months compared with those who lengthened at 12 months.