The purpose was to investigate back pain and disability and their relationship to vertebral changes in patients with untreated Scheuermann's.

Overall, 136 patients who had attended the outpatient clinics between 1950 and 1990 for Scheuermann's were contacted, 49 of them (12 females, 37 males) responded. There was no difference in the baseline data between responders and non-responders. From radiographs, th-kyphosis, l-lordosis, and scoliosis were measured. The number of affected vertebrae and the degree of wedging were registered. Anthropometric data, occurrence of back pain, disability scores, and employment status were compared to a representative sample (n=3835) of the normal population.

After mean follow-up of 37 (6.5;25.9-53.7) y, their average age was 58.8 (8.2;44.4.-79.3) y. Male patients were significantly taller than the control subjects. Female patients were on average 6 kg heavier (P=0.016) and their mean BMI was higher (23.9 kg/m² vs 20.8 kg/m²,P=0.001) at age 20 than in the controls.

Females had a greater mean kyphosis than males (51.7 vs. 43.2°, p=0.11). There was no correlation between the degree of thoracic kyphosis and disability. Scheuermann's patients had an increased risk for constant back pain (P=0.003), a 2.6-fold risk for disability because of back pain during the past 5 years (P=0.002), a 3.7-fold risk for back pain during the past 30 days (P<0.001), and a 2.3-fold risk for sciatic pain (P=0.005). They reported a poorer quality of life (p<0.001) and general health (p<0.001). There was no difference in working ability and employment status between patients and controls.

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: To determine whether in operatively treated scoliosis patients loss of correction after implant removal for late infection can be avoided by reinstrumentation.

Methods: A retrospective review of 937 scoliosis patients treated by instrumented posterior fusion. Forty-þve (5%) developed late infection 2.9±1.7(0.5–8.0) yrs p.op. They were treated either by implant removal alone (HR, n=35) or by implant removal, re-instrumentation and augmentation of fusion (RI& F, n=10). Pseudarthrosis was found in 5 patients. Wound healing was uneventful in all patients of both groups after revision. There was no difference in mean Cobb angles between the groups neither before initial scoliosis operation nor before the revision.

The mean follow-up time after revision was 4 years. Results: Radiographically, there was a signiþcant loss of correction after revision operation. At the time of reoperation mean curve correction was 40.4%, being 28.8% at follow-up (p< 0.05).

There was a signiþcant difference in the radiographic outcome between the two revision techniques: In the RI& F-Group, the þnal thoracic Cobb angle correction. was 45.1% as compared to 20.8% in the HR-Group (p=0.03).

Conclusions: One-stage hardware removal and re-instrumentation is a safe procedure and prevents loss of correction in the treatment of late infection after posterior instrumentation and fusion for scoliosis.

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 find a long-term effect of posterolateral fusion for isthmic spondylolysis and spondylolisthesis on lumbar spine.

Methods: A posterolateral fusion was performed on 56 patients (30 females, 26 males) with an average age of 16 (range 11 to 20) years. A clinical and MRI examination was performed on these patients on average 18 years later (range 11 to 25 years). The size of the spinal canal were assessed. Disc space, degeneration and protrusions were evaluated. Bone marrow changes (Modic I & II), facet joint degeneration and the state of the spinal muscles were assessed.

Results: In MR images, none of the patients had lumbar spinal stenosis. In contrast, the spinal canal was wide in the level spondylolysis and spondylolisthesis. Narrowing of the neural foramina was noted in 13 (23%) patients. This was associated usually in severe slip (> 50%) and was noted always at the L5-S1 level. Of the studied 332 intervertebral discs 56 (17%) were speckled and 57 (17%) were black and 76 (23%) narrowed. Most commonly speckled/black and narrowed disc was found in the two lowest lumbar levels. Only one patient, 41-year-old female, had prolapse. Modic I and II changes were noted in 7 (2%) and 9 (3%) intervertebral disc levels, respectively. Degenerative-like facet joint hypertrophy was noted in 47 (48%) of the studied levels. Of the patients, seven (12%) had muscular atrophy.

Conclusions: Stenosis of neural foramina may be associated to severe spondyolisthesis. Degenerative changes were found most commonly found in the level of the spondylolysis and spondylolisthesis and above fusion level. Bone marrow changes associated with disc degeneration were rare.

Stereotactic principles used primarily for brain surgery have been developed further and introduced into spine surgery at the beginning of the 1990’s. The system solutions available consist of three components: the surgical object (vertebra), the virtual object (CT-image data of the vertebra), and the navigatorallowing the surgeon to localise the position of the instrument inside the surgical object in real-time. Optoelectronic systems using infrared light emitting diodes and magnetic field based navigators are in use.

Lumbar pedicle screw insertion was the first clinical application for this technique. Screws can be positioned safely following a preplanned optimal trajectory or according to the anatomic situation utilising the real-time module intraoperatively.

The effectiveness of this new technique has been shown in prospective studies (Schwarzenbach et al 1997, Laine et al 1997, 1999).

In a a prospective randomised clinical trial one-hundred consecutive patients were randomly allocated for either conventional (Group 1) or computer assisted (Group 2) pedicle screw insertion. From the computer assisted group nine patients were dropped out. There was no statistical difference between the groups. CT-based optoelectronic navigation was used for screw insertion in Group 2. The screw position in the pedicle was assessed postoperatively by an independent observer with CT.

The pedicle perforation rate was 13.4% (37/277 screws) in the conventional group and 4.6% (10/219 screws) in the computer assisted group (P=0.006). The majority of perforations was less than 4 mm. A pedicle perforation of 4 to 6 mm was found in 1.4% (4/277) of the screws in Group 1, and none in Group 2. Intraoperatively, eleven screws were repositioned in Group 1 and none in Group 2. There were no postoperative complications related to screw placement.

We conclude that higher accuracy of pedicle screw insertion with computer assisted navigation than with conventional methods could be demonstrated under clinical conditions in a randomised controlled clinical trial.

At present CAOS Systems are used also for localisation of intraosseous pathologic processes during biopsies in spine and pelvis, sacroiliac screw fixation and vertebral osteotomies.

Refinement of the method for use in minimal invasive and percutaneous procedures is in progress.

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.

The goal of the present study is to investigate if one of the two dorsal operative procedures (rod-rotation versus translation technique) leads to a better radiographic correction of idiopathic adolescent thoracic scoliosis after operative treatment.

The operative technique in scoliosis surgery introduced by Cotrel and Dubousset attempts to achieve an improvement of the sagittal profile and a derotation of the vertebrae, in addition to a correction of the main curvature of the scoliotic spine by rotation of the convex-side rod (rod-rotation). The technique of segmental correction was described by Luque. Correction of the scoliosis is performed after fixation of each vertebral body with wire cerclages, followed by segmental correction of the deformed spine. The Universal Spinal System was introduced and an operating technique was developed to take advantage of the principle of segmental correction of scoliosis (translation technique).

The radiographic outcomes in two groups comprising a total of 69 adolescent patients treated for idiopathic thoracic scoliosis with dorsal instrumentation by the use of a unified implantation system (Universal Spinal System) were compared retrospectively by an independent observer. In 30 patients an intraoperative correction of the scoliosis was performed by translation technique (translation group) and in 39 patients the correction was achieved by Cotrel-Dubousset instrumentation (rod-rotation group). The mean follow-up interval was 40 months with a minimum of 12 months. The preoperative radiographic measurements of the scoliotic spines showed no significant differences between the two groups.

In both patient groups, the thoracic primary curve, lumbar secondary curve, and apical rotation of the thoracic curve were improved by the operation. The thoracic primary curve was corrected from 50 6° to 24 7° (p< 0.01) in the translation group and from 54 11° to 22 11° (p< 0.01) in the rod-rotation group. The extent of the correction of the thoracic curve was significantly greater in the rod-rotation group than in the translation group (59% versus 52% correction; p< 0.01). Thoracic apical rotation was corrected from 21 ± 9° to 16 ± 10° (p< 0.01) in the rod-rotation group and from 19 ± 9° to 17 ± 7° (p< 0.05) in the translation group. Lumbar apical rotation and the sagittal profile were unchanged in both groups.

Based on the results of this study with a small number of patients, the ability of the translation technique to correct the thoracic major curvature seems to be less than that of the rod-rotation technique. No differences are to be expected in the correction of the lumbar minor curvature or of the rotation of the thoracic apex. Neither procedure is expected to influence the sagittal profile or lumbar rotation.

From 1948 to 1980, 93 children and adolescents had fusion in situ for severe spondylolisthesis with a slip of 50% or more, at a mean age of 14.8 years. Of these, 52 girls and 35 boys were reviewed after a mean follow-up of 13.8 years. The mean pre-operative slip was 76% and pain frequency correlated with the severity of the lumbosacral kyphosis but not with that of the slip. Posterior fusion was used in 54, posterolateral in 30 and anterior fusion in three patients. There were no major complications but 16 had re-operations for non-union or root symptoms. At follow-up there were three non-unions. After operation, 19 patients had 10% or more progression of the slip, but 10 showed correction by more than 10% as a result of remodelling. The lumbosacral kyphosis had increased by more than 10 degrees in 45%. Postoperative progression of the slip and of lumbosacral kyphosis was significantly more if the posterior element had been removed. At follow-up 77 patients were subjectively improved, four were unchanged, and one was worse. These results did not correlate with either the degree of the slip, or the angle of lumbosacral kyphosis. Fusion in situ is safe and gives good long-term clinical results. Secondary changes are associated with increased lumbosacral kyphosis, so reduction of this should be considered in severe cases.