The change of position of the distal pedicle screws with growing rods in relation to vertebral bodies was described as pedicle screws migration. Pedicle screws are subjected to serial distractive forces pushing them down with every distraction; additionally there is continuous growth of the vertebral bodies during the treatment period. These two factors can affect the change of position of the pedicle screws in relation to the vertebrae during the use of growing rods. To our knowledge, this finding has never been studied, confirmed, or quantified. This is a retrospective review of the radiographs and operative notes of 23 consecutive cases of early-onset scoliosis treated with single growing rods. Age at index surgery ranged from 4 years 2 months to 8 years 9 months, and the number of distractions was four to 11 per patient. Measurements were done on post-index and latest follow-up true lateral radiographs. With optimum initial position of the screws in the pedicle, we calculated the distance between the upper end plate and the pedicle screw (distance superior to the screw [SS]) and the distance between the screw and lower-end plate (distance inferior to the screw [IS]). We expressed this ratio as a percentage: SS/IS x 100%. Any increase in this percentage with time denoted a more caudal position; however, a change in the percentage of less than 10% was regarded as insignificant.Introduction
Methods
Spinal Deformity Service, Royal Orthopaedic Hospital, Birmingham, UK To describe the technique of nonfusion annulotomy and nuclectomy with posterior growing rod instrumentation for the treatment of non-congenital early onset scoliosis To present our results of the application of this technique in a consecutive series of nine patients with mean follow up of 76 months (range 16 to 123 months) We undertook retrospective observational casenote and radiograph study of patients with noncongenital early onset scoliosis having annulotomy and nuclectomy at the apex of their respective curves with standard posterior growing rod instrumentation between 1998 and 2009. 10 patients were identified with one excluded due to short follow up period. Of the nine patients included mean follow up was 76 months. Mean age at primary surgery was 71.7 months (range 29- 97 months) We measured pre and post operative Cobb angle, T1-S1 height change and change in height over the apical segments. Mean pre op cobb angle was 74° (range 62- 81°). Mean post op cobb angle was 38°. Three patients have completed their treatment programme with a mean number of 9 lengthenings achieved. Six patients are still undergoing lengthenings. CT demonstrates that the annulotmized segment does not fuse at a mean 3.5 years postoperatively. All patients demonstrated growth over total spinal height and also over apical segments which had undergone annultomy/ nuclectomy. We also report complications. We have demonstrated that anterior annulotomy and nuclectomy with posterior growing rod construct does allow for spinal growth over released segments without autofusion.
The management of spinal deformity in children
with univentricular cardiac pathology poses significant challenges to
the surgical and anaesthetic teams. To date, only posterior instrumented
fusion techniques have been used in these children and these are
associated with a high rate of complications. We reviewed our experience
of both growing rod instrumentation and posterior instrumented fusion
in children with a univentricular circulation. Six children underwent spinal corrective surgery, two with cavopulmonary
shunts and four following completion of a Fontan procedure. Three
underwent growing rod instrumentation, two had a posterior fusion
and one had spinal growth arrest. There were no complications following
surgery, and the children undergoing growing rod instrumentation
were successfully lengthened. We noted a trend for greater blood
loss and haemodynamic instability in those whose surgery was undertaken
following completion of a Fontan procedure. At a median follow-up
of 87.6 months (interquartile range (IQR) 62.9 to 96.5) the median
correction of deformity was 24.2% (64.5° (IQR 46° to 80°) We believe that early surgical intervention with growing rod
instrumentation systems allows staged correction of the spinal deformity
and reduces the haemodynamic insult to these physiologically compromised
children. Due to the haemodynamic changes that occur with the completed
Fontan circulation, the initial scoliosis surgery should ideally
be undertaken when in the cavopulmonary shunt stage. Cite this article:
