Introduction: With the advent of thoracoscopy, anterior release procedures in adolescent idiopathic scoliosis (AIS) have come into more frequent use, however, the indication criteria for an anterior release in thoracic AIS are still controversial in the literature. The aim is to achieve a better coronal correction but the benefit as compared to a single posterior approach is not yet clarified.

Material and Methods: Two groups of 15 patients each were matched for sex, age and cobb angle. Patients of group 1 were operated with a staged procedure of an anterior release followed by posterior instrumentation (anterior-posterior spinal fusion, APSF) and patients of group 2 were operated by a single posterior spinal fusion (PSF) with performance of concave sided rib osteotomies (concave thoracoplasty, CTP).

Results: Mean age: 16.2 y (APSF), 17.6 y (PSF). Mean preop curve: 81.7° ± 10.1° (APSF), 84.2° ± 14.1° (PSF). Mean postop curve: 34.9° ± 15.5° (APSF), 34.3° ± 12.2° (PSF) (p=0,49).

Conclusion: The single posterior approach gave the same coronal correction rate as compared to patients operated with a two stage procedure with preceding anterior release. A posterior release with CTP is more effective in increasing spinal flexibility than disc excision. According to our clinical experience, an anterior release prior to posterior instrumentation in AIS should only be considered in hyperkyphosis, coronal imbalance or massive curves.

Continuous passive motion has been shown to be effective in the conservative treatment of idiopathic club foot. We wished to determine whether its use after operation could improve the results in resistant club feet which required an extensive soft-tissue release. There were 50 feet in the study. Posteromedial lateral release was performed in 39 feet but two were excluded due to early relapse. The mean age at surgery was eight months (5 to 12). Each foot was assigned a Dimeglio club foot score, which was used as a primary outcome measure, before operation and at 6, 12, 18 and 44 months after. Nineteen feet were randomly selected to receive continuous passive motion and 18 had standard immobilisation in a cast.

After surgery and subsequent immobilisation in a cast the Dimeglio club foot score improved from 10.3 before to 4.17 by 12 months and to 3.89 at 48 months. After operation followed by continuous passive motion the score improved from 9.68 before to 3.11 after 12 months, but deteriorated to 4.47 at 48 months. Analysis of variance adjusted for baseline values indicated a significantly better score in those having continuous passive motion up to one year after surgery, but after 18 and 48 months the outcomes were the same in both groups.

Study Design: Experimental in vivo study on New Zealand white rabbits.

Summary of Background Data: Bone Morphogenetic Protein 2 (BMP-2) is of increasing orthopaedic interest due to its osteo-inductive potency. Currently it is used in human and animal studies for posterolateral spinal fusions. However, little data is available concerning the pathophysiologic role of BMP-2 in normal and degenerated discs.

Methods: A recently established animal model was used to create mechanically induced disc degeneration of one single segment. In 6 animals, an external disc compression device was attached for 28 days. For comparison 8 animals underwent a sham operation.

Outcome Measures: The discs were analysed by a) immunohistology to determine protein content of BMP-2 and b) real time RT-PCR to quantify RNA content of BMP-2.

Results: Sham controls showed a homogeneous distribution of BMP-2 throughout the annulus fibrosus and cluster-like accumulation within the nucleus pulposus. Mechanically degenerated discs determined a reduction of positive cells with areas lacking BMP-2. Real time RT-PCR results demonstrated a statistically significant (7.92 times) upregulation of BMP-2 as compared with shams (p=0.033).

Conclusions: Mechanically induced disc degeneration is associated with a loss of BMP-2 protein. Disc cells respond with a stimulation of BMP-2 gene expression. This data confirms the role of BMP-2 in the pathophysiology of disc remodeling. It remains unclear if this mechanism of BMP-2 stimulation contributes to the disc reorganization alone or if it may also play a role in osteo-inductive processes like osteophyte formation or endplate sclerosis.

Study Design: Experimental in vivo study on New Zealand White Rabbits.

Summary of Background Data: We have developed an in-vivo rabbit model of lumbar disc degeneration. This model provides a defined loading of one single disc. However, the molecular mechanism that leads to mechanically-induced disc degeneration remains unclear.

Objective: To investigate the process of mechanically induced disc degeneration in New Zealand White Rabbits with respect to remodeling on the gene and the level of protein expression.

Subjects: Seven animals were treated with an external compression-device applying 200N on segment L3/4. Eight animals underwent sham surgery.

Outcome Measures: After 28 days discs were harvested and cut into two pieces in a sagittal plain. One piece was used for protein analysis utilizing immunohistochemical protocols for collagen I, II and aggrecan. The other half of the disc was used for quantitative real-time RT-PCR to determine gene expression of selected matrix genes.

Results: In the compression group matrix genes were upregulated: collagen I (6.46x; p=0,018), collagen II (2.14x), biglycan (2.97x; p=0,049), decorin (4.64x; p=0,043), aggrecan (1.2x), osteonectin (2.03x), fibronectin (3.48x), fibromodulin (2.6x; p=0,037). The MMP-13 gene could only be detected in compressed discs. Gene transcripts of the metalloproteinase-inhibitor TIMP-1 were 4.5 times upregulated (p=0,007). Immunohistochemical analysis revealed a decrease of aggrecan and collagen I.

Conclusions: In our animal model mechanical loading caused degradation of the matrix proteins collagen I and aggrecan. Metalloproteinases like MMP-13 trigger this degenerative process. The elevated expression of matrix genes and TIMP-1 transcripts may characterize a mechanism of compensation.

We have investigated the effect of multisegmental spinal fusion on the long-term functional and radiological outcome in patients with scoliosis. We compared these patients both with those whose spine had not been fused, and with a control group.

We studied 68 patients with idiopathic scoliosis (34 operative and 34 non-operative) who had been followed up for a minimum of five years after treatment. They were matched for age (mean 44 years) and Cobb angle (mean 54°) at follow-up. An age- and gender-matched control group of 34 subjects was also recruited.

All participants completed a questionnaire to assess spinal function and to grade the severity of back pain using a numerical rating scale. Radiographs of the spine were taken in the patients with scoliosis and lumbar degenerative changes were recorded.

The spinal function scores for the patients with scoliosis who had had a fusion were similar to those who had not. Both scoliosis groups, however, had lower scores than the control group (p < 0.001). The frequency and severity of back pain were lower for patients with scoliosis and fusion than for those without, but higher for both scoliosis groups compared with the control group. Radiographs showed similar degenerative changes in both scoliosis groups.

We studied 21 former top-class competitive javelin throwers to investigate radiological and clinical symptoms in the lumbar spine many years after the end of their athletic careers. The athletes underwent clinical and radiological examinations at an average of 20 years after retiring from athletics. The Hannover questionnaire was used to evaluate functional restrictions in daily living.

Degenerative changes in the lumbar spine were more marked towards the caudal aspect of the spine. Ten athletes also had spondylolisthesis, but with little progression (< 15%) throughout the observation period. Athletes both with and without radiologically demonstrated spondylolisthesis, complained of no more back problems than the normal population (93% for athletes v 86% for controls). Slight progression followed their retirement from athletics.

We analysed the cases of lumbar kyphosis in 151 (21%) of a series of 719 patients with myelomeningocele. Three different types were distinguished: paralytic, sharp-angled and congenital. In a cross-sectional and partly longitudinal study the size and magnitude of the kyphosis, the apex of the curve and the level of paralysis of each group were recorded and statistically analysed.

Paralytic kyphosis (less than 90° at birth) occurred in 44.4% and increased linearly during further development. Sharp-angled kyphosis (90° or more at birth) was present in 38.4% and also showed a linear progression. In both types, progression seemed to depend also on the level of paralysis. Congenital kyphosis occurred in 13.9% and we could find no significant factor which correlated with progression.

In 21 children with myelomeningocele who underwent kyphectomy for congenital kyphosis of the lumbar spine, aortography revealed no case in which the aorta followed the spinal curvature. Many anomalies of the intercostal and segmental arteries were demonstrated which were only in part associated with deformities of the respective vertebral bodies. The kidneys, which were frequently malformed, often lay within the kyphosis and were therefore at risk of operative damage. We conclude that the aorta is not at risk and that aortography is not usually necessary before kyphectomy, except in patients who have undergone prior abdominal surgery. Non-invasive methods (ultrasound, CT or MRI) should be used to detect malpositions and malformations of the kidneys.