The purpose was to analyze preoperative symptoms, curve characteristics, and outcome of surgery in patients operated on for isthmic spondylolisthesis with concomitant scoliosis. Overall, 151(9.1%) of 1667 scoliosis patients had spondylolisthesis treated surgically in 21 (13.9%)(19 females, 2 males; 11 low-, 10 high-grade). Patients' age at admission was 13.5(10-17)y. Preoperatively, 5/21 were pain-free (1 high-grade, 4 low-grade), 7 (2 high-grade) had LBP, 2 (both high-grade) radiating pain, and 7 (5 high-grade) had both. Hamstring tightness was present in 5/10 high-grades. Scoliosis was primary thoracic in 3/11 low-grade and secondary lumbar with oblique rotated take-off of L5 in 8/11 low-grade patients. Of the high-grades, 7/10 had sciatic curves and 3 secondary lumbar. In low-grades, the main indication for surgery was pain in 3/11 and lumbar curve progression or the intent to prevent it in 7/11. The operative technique was uninstrumented posterolateral fusion in 8/11, instrumented L4-S1 fusion with reduction of L4-tilt in 2, and direct repair in 1 patient. High-grades were fused to prevent further slipping regardless of subjective symptoms (uninstrumented anterior 5, combined 2, instrumented reduction 3). Selective thoracic fusion for scoliosis was performed in 3 patients. None of the lumbar curves needed fusion. All sciatic curves resolved. The follow-up time was 10.6(2-21)y. Of the low-grade patients, 5 were pain-free, 4 had moderate pain, and 2 had a severe chronic pain syndrome. One had broken pedicle screws without sequelae. Of the high-grade patients, 4 were pain-free, 6 had moderate pain. One had a pain-free peroneal weakness after slip reduction.

Study design

Literature review of the best available evidence on the accuracy of computer assisted pedicle screw insertion.

Background

Improvement of Scheuermann's thoracic kyphosis in the growing spine with Milwaukee brace treatment has been reported. However, the role of brace treatment in Mb. Scheuermann is controversial.

We report results of brace treatment by low profile scoliosis module with sternal shield.

Aims: Computer guidance has improved the accuracy and safety of pedicle screw insertion. The aim of this study was to evaluate whether CT-based computer assisted pedicle screw insertion enhances the clinical results of lumbar fusion. Methods: 100 lumbo- and thora-columbosacral operations were randomized either into i) conventional pedicle screw insertion (Group 1) or into ii) computer assisted technique using the SurgiGATE Spine 2.1 optoelectronic navigation system (Group 2). Clinical results were analyzed using the Oswestry index. Radiological analysis was performed by an independent radiologist. Results: 95 patients completed the follow-up. Three had died and two were lost. Thus, there were 48 patients (265 screws) in Group 1, 38 patients (201 screws) in Group 2, and 9 dropouts from the original randomization. There was no statistical difference between the groups regarding age, gender, diagnosis, type of operation, operating time or number of screws per patient. The follow-up time was 24.2 ± 1.6 months. The preoperative Oswestry score in Group 1 was 47.7 ± 16.6, and in Group 2 51.4 ± 16.3 (NS). The postoperative scores were, respectively, 27.1 ± 19.1 and 30.8 ± 22.7 (NS). The fusion rate in Group 1 was 85.1%, and in Group 2 92.1% (NS). In Group 1 4.5% of the screws were loose or broken as compared to 7.0% in Group 2 (NS). Conclusions: Despite superior accuracy, at 2-year follow-up no clinical benefit from computer assisted pedicle screw insertion could be demonstrated in this randomized controlled clinical study.

Aims: To determine whether certain motion parameters could be linked to clinical signs and symptoms of instability in a group of chronic LBP patients. Methods: Thirty-four patients enrolled for an external þxation (ESF) test performed active ßexion-extension, axial rotation, and lateral bending motions, during which the relative motion between marker carriers attached to the Schanz screws was measured with an optoelectronic camera. The rotations of the vertebrae were analysed with special reference to ranges of motion, motion asymmetries, and coupled motions. Studentñs t-test was used to determine whether these parameters were signiþ cantly different between the patient groups that did and did not receive pain relief from the stabilization of the suspected painful segment/s. Results: The improvement of the patientñs functional status during the external þxation as well as after subsequent lumbar fusion surgery was signiþcantly correlated with the extension ROM (p=0.049 and p=0.036), and the ratio of extension to ßexion ROM (p=0.035 and p=0.044) at the index levels before surgery. No signiþcant correlations with the other motion pattern parameters were observed. Conclusions: In case of a positive ESF test, preserved motion at the symptomatic level/s before the surgery seemed to predict a favorable fusion outcome. On the other hand, abnormal patterns of asymmetry and coupled motion did not seem to be associated with pain relief after stabilization of the suspected painful segment/s.

We performed a biomechanical study on human cadaver spines to determine the effect of three different interbody cage designs, with and without posterior instrumentation, on the three-dimensional flexibility of the spine. Six lumbar functional spinal units for each cage type were subjected to multidirectional flexibility testing in four different configurations: intact, with interbody cages from a posterior approach, with additional posterior instrumentation, and with cross-bracing. The tests involved the application of flexion and extension, bilateral axial rotation and bilateral lateral bending pure moments. The relative movements between the vertebrae were recorded by an optoelectronic camera system.

We found no significant difference in the stabilising potential of the three cage designs. The cages used alone significantly decreased the intervertebral movement in flexion and lateral bending, but no stabilisation was achieved in either extension or axial rotation. For all types of cage, the greatest stabilisation in flexion and extension and lateral bending was achieved by the addition of posterior transpedicular instrumentation. The addition of cross-bracing to the posterior instrumentation had a stabilising effect on axial rotation. The bone density of the adjacent vertebral bodies was a significant factor for stabilisation in flexion and extension and in lateral bending.