Spinal Biomechanics Lab, Baylor College of Medicine, Houston, Texas, USA

Documenting the patterns and frequency of collapse in non-operatively managed spine fractures, using a motion analysis software.

Retrospective analysis of prospective case series

105 patients with thoracic or lumbar fractures, were neurologically intact, and treated non-operatively for the ‘stable’ injury at our unit between June 2003 and May 2006. The mean age of the cohort was 46.9 yrs

Serial radiographs (mean 4 radiographs/patient; range 2 – 9) were analysed using motion analysis software for collapse at the fracture site. We defined collapse as a reduction of anterior or posterior vertebral body height greater than 15% of the endplate AP width, or a change in the angle between the inferior and superior endplates > 5°.

The changes were assessed on serial radiographs performed at a mean of 5.6 mo (95% CI 4.1 – 7.1 mo) after the initial injury. 11% showed anterior collapse, 7.6% had posterior collapse, 14% had collapse apparent as vertebral body wedging, and 17% had any form of collapse. ODI scores were obtained in 35 patients at the time of the last available radiograph. There were no significant differences in ODI scores that could be associated with the presence of any form of collapse (p > 0.8 for anterior collapse; and p = 0.18 for posterior collapse).

This pilot study with the motion analysis software demonstrates that some fractures are more likely to collapse with time. We hope to carry this work forward by way of a prospective study with a control on other variables that are likely to affect the pattern and probability of post-fracture collapse, including age, bone density, vertebral level, activity level, fracture type.

Objective: To assess the temporal geometric sagittal profile changes on serial radiographs of fractures of the thoracic and thoraco-lumbar spine.

Materials and methods: We have included 103 patients with thoracic or lumbar fractures were treated at our unit between June 2003 and May 2006. The patients were suitable for non-operative treatment. The mean age of the cohort was 46.9±2.4 (16–90). The sex distribution was equal. 94 patients had a single level lesion. 19 fractures were in the thoracic spine; 64 in the thoraco-lumbar (T11-L1) and 29 between L2 and L5. The radiographs were scored using the AO classification by 2 senior orthopaedic trainees. The radiographs were analysed at the Spine Research Laboratory. The results were computed using Stat, a statistical software.

Results: The changes were assessed over a mean period of 5.6 mo (range 1–49 mo; 95% CI 4.1–7.1 mo). Weighted kappa score of 0.58 was computed for the primary fracture type and 0.22 for the fracture sub-types. The inter-observer rater agreement was similar to that reported in literature. 7 patients showed a significant collapse. We report the association between the fracture types and the extent of collapse. We have also assessed the association between the medium to long term symptoms, the fracture types and the extent of collapse at the fracture sites and the adjacent disc.

Conclusion: Some fracture sub-types are more likely to collapse and cause long term symptoms. Identifying these fractures at the outset would help clarify surgical indications.

Objective: To do assess changes in patients’ symptoms and the operative plan.

Materials and methods: 147 patients on a spinal surgery waiting list were assessed at a mean wait of 15.8 ± 1.3 months. 89 (61%) were male and 58 (39%) were female at a mean age of 49.7 yrs (16–78). 123 patients had a degenerative condition (20 cervical; 03 lumbar); 20 patients were seen for scoliosis; 2 with a post-traumatic kyphosis and 1 each with ankylosing spondylitis and a psudarthrosis.

Outcomes assessed: Changes in patients symptoms; changes from the initial operative plan when listed; requirement for re-imaging due to the wait.

Results: 31 patients reported improved symptoms at the re-assessment, while 96 were worse off and 20 were unchanged. 137 had axial pain when listed which changed to 116 at review (p=0.0018). 130 had radicular pain when listed which improved to 80 on re-assessment (p< 0.0001). However 19 reported an increase in the axial and 17 in the radicular symptoms. 71 patients (48.3%) required to be re-imaged at the re-assessment due to changes in the clinical picture. 42 patients received the procedure as originally listed. 30 patients were taken off the list, 24 received a different operation, and 38 had an interim or a definitive needling procedure while 13 await a re-assessment.

Conclusions: On the basis of the observations on our cohort, 1 in 5 operations were cancelled; 65% had an increased severity of the symptoms and just 1 in 3 patients were operated as planned while 48% required re-imaging. A long wait inevitably leads to changed symptoms and a review of these patients is mandatory. The review and the re-imaging adds to the burden on the already over-loaded system.

Background: Thoraco-lumbar fractures without a neurological deficit are usually suitable for non-operative treatment. The main area of clinical interest is the deformity at the injured levels. The deformity may be evident at the time of presentation, though could be expected to progress in time.

Objective: Accurate assessment of the temporal behaviour in the geometry of the injured segments in non-operatively treated thoracolumbar fractures with normal neurology.

Materials: 102 patients with thoracolumbar fractures without a neurological deficit were treated non-operatively at our unit between June 2003 and May 2006. The mean age of our patient cohort was 46.9 yrs (16–90 yrs). Strict criteria were followed to determine suitability for non-operative treatment. Supine radiographs were performed at the initial assessment. Erect radiographs were performed when trunk control was achieved and at follow-up assessments thereafter.

Methods: Quality Motion Analysis (QMA) software (Medical Metrics Inc, Houston, Tx) was used to measure rotational and translation changes between the end plates using a validated protocol. The radiographs were standardised for magnification and superimposed from different time points. Transformation matrices were used to track the changes. The AO classification was used to classify the fractures by 2 independent observers.

Results: A median of 4 radiographs were analysed for each patient (range 2–9), at a mean follow-up of 5.6 mo (95% CI 4.1–7.1 mo). 92% of the cohort had sustained a 1 level injury. 76% of the injuries were between T12 and L2; 19% were in the thoracic spine. An inter-observer rating of 0.58 was obtained for the classification of the primary fracture type. The mean rotational change was −1.4855° ± 0.248° (95% CI: −0.994° to–1.976°). The mean anterior vertebral body height collapse was −4.3444° ± 0.6938 (95% CI: −2.695 to −5.724). The mean posterior vertebral height collapse was −0.7987 ± 0.259 (95% CI: −0.284 to −1.313).

Conclusions: We report the use of QMA software to track changes in the vertebral body geometry accurately. This has implications on the clinical aspects of management of thoracolumbar fractures based to progression of deformity that could be explored in future studies.

Objective: Prolonged waiting time after being referred for a specialist opinion has plagued the NHS despite pressures to deliver optimum healthcare. We have assessed changes in clinical situation in patients referred to a spinal service while awaiting the first assessment.

Materials & Results: 89 patients were referred to our unit between Jan 2001 and December 2004. The gender distribution in this cohort was equal and the mean age was 50.7 yrs. The mean delay for being seen in the clinic was 28.4 mo (16–58 mo). Significant changes in the symptom pattern were noted in 46 patients, of which 8 patients reported radicular symptoms on a different side. In addition, 7 patients experienced an increased severity in the existing symptoms. 43 patients had been referred to us with an MRI. However due to the delay, 20 of these patients required re-scanning. Following the clinical assessment 25 patients were referred for Physiotherapy, 4 patients required a further clinical review and 44 patients were referred for further imaging.

Conclusion: The problem of excessive out-patient waiting time results in changes in symptom patterns and an increase in the severity of existing symptoms. The changes frequently results in an increased requirement of re-imaging.

Objective: The purpose of this study is to determine the accuracy of the push-pull radiographs in predicting the surgical correction in neuromuscular scoliosis.

Study Design: Retrospective radiographic review.

Subjects: Radiographs of 26 patients with neuromuscular scoliosis secondary to Duchennes Muscular Dystrophy were reviewed. All the patients had a posterior instrumented correction of the deformity by the same surgeon with the Universal Spinal System. Duchennes Muscular Dystrophy was chosen as a model for neuromuscular scoliosis since it represents a homogenous group with regards to the spinal deformity.

Outcome measures: The Cobb angle, the translation of the apex of the deformity from the central sacral line, pelvic tilt and the number of motion segments in the curve were compared between pre-operative erect, push-pull view and the post-operative radiographs. Results were analysed using student’s t test for significance and Pearson’s coefficient for correlation with the SPSS software.

Results: A correlation was seen in the form of an improvement in the Cobb angle, pelvic tilt and the apical translation when comparing the push-pull views and the post-operative radiographs. The improvement was statistically significant.

Conclusion: The push-pull view provides an adequate assessment of the fl exibility that guides a safe deformity correction.

Objective: To assess the effect of spinal surgery and nocturnal ventilation on lung function and survival in patients with scoliosis secondary to Duchenne Muscular Dystrophy.

Study design: Prospective, observational study by a single observer (Research Physiotherapist).

Subjects: 80 patients with Duchenne Muscular Dystrophy were treated between 1986 and 2002. During this period 40 patients underwent a spinal fusion at a mean age of 14.05y (95 % CI 13.6 – 14.6). Nocturnal ventilation was commenced when symptoms and signs of respiratory failure were evident. The mean FVC at commencement of nocturnal ventilation was 0.41 litres. The patients were divided into 2 groups based on whether they received nocturnal ventilation. A total of twenty eight patients received nocturnal ventilation and 52 did not. The groups were further sub-divided based on whether they had spinal fusion. There were fourteen patients in each sub-group of the ventilated group and 26 patients in each sub-group of those that were not ventilated.

Outcomes: Serial forced vital capacity (FVC) measurements and survival measured by Kaplan Meir survival analysis.

Results: The mean vital capacity dropped from 1.41 l (95 % CI 1.21 – 1.61) to 1.13 (95 % CI 0.893 – 1.37), a year post-operatively. This was not associated with the development of respiratory compromise. The vital capacity improved gradually, reaching the pre-operative level before it declined again. The shortest survival was seen in patients who received neither surgery nor ventilation (median survival 19.7y). The patients who received surgery but no ventilatory support were not as good as the patients that were ventilated but did not have surgery (median survival 24.3y). The best results were seen in the patients who had both surgery and ventilation (median survival 26.4y). The worst prognosis is in patients with early onset symptomatic cardiomyopathy (6 patients, with a median survival of 16.3y).

Conclusion: Nocturnal ventilation is the most important factor in the improvement in survival of patients with Duchennes muscular dystrophy. Spinal surgery is also beneficial and the best results are in those patients who have both.