Introduction

Idiopathic scoliosis is a spine disorder of unknown origin with a prevalence of 1·5-3% in the general population. Apart from the large multifactorial form sample of idiopathic scoliosis, there is a good evidence for the existence of a monogenic subgroup in which the disease is inherited in a dominant manner. However, results from published work suggest a strong heterogeneity in locations of the mutated genes.

Introduction

Atlanto-occipital dislocation is rare and usually fatal. Stabilisation is typically from Occiput to C2, sacrificing atlanto-axial movement. To preserve movement, screw fixation from the articular mass of C1 to the occipital condyle has been described. Amongst other structures, the hypoglossal nerve is at risk. No previous study has addressed the anatomy of the hypoglossal canal in relation to screw trajectory. We aim to identify landmarks to aid safe screw passage into the occipital condyle.

Objective: In 1989 Mirels published a scoring system for identifying impending pathological fractures in long bones. However, the spine is the most common site of skeletal metastases. A MR-based scoring system is proposed to quantify the risk of sustaining a pathological fracture through a metastatic lesion in a vertebral body.

Methods: A retrospective analysis of 101 vertebral body metastatic lesions was carried out. The metastases were identified through the onco-radiology database. Only lesions with a MR scan and subsequent imaging within 24-months of the index scan were included. Variables potentially predictive of impending fracture were analysed for significance. The significant variables were then statistically weighted. The original MR scans were scored, and the subsequent imaging was used to identify which lesions fractured. The scores were compared between the fracture and non-fracture group. Analysis was carried out for each predictive variable to establish whether they were individually as good as the scoring system alone in predicting fracture. Intra and inter-observer variability was assessed using kappa statistics.

Results: Twenty-one of the 101 lesions fractured within 24 months. A mean score of 0.65 was identified in the non-fracture group, whilst the fracture group had a mean score of 6.52 (p< 0.0001). The percentage risk of a lesion sustaining a pathological fracture was calculated for any given score. As the score increased above 4, so did the percentage risk of fracture (sensitivity 85.7%, specificity 97.5%). Very good intra and inter-observer agreement was present, showing the scoring system to be reliably reproducible.

Conclusions: The authors propose that all painful vertebral body metastatic lesions be evaluated by MR scanning. Lesions with a score of 3 or less can be left untreated. Lesions with scores of 4 or higher are at risk of fracture and should be considered for prophylactic cement augmentation.

The SF 36 questionnaire has been validated and used in multiple studies. However, it remains unclear how well patients complete the SF-36 questionnaire in a spinal outpatient clinic setting outside the context of a study. We aim to assess the quality of information gained if the SF 36 is used as an audit and outcome measure in real clinical practice.

The SF 36 has been used in our clinic as a routine for the initial assessment and outcome audit of patients for the last 4 years. A prospective, consecutive sample of 85 patients’ SF-36 forms was evaluated during a spinal out-patient clinic over one month at our teaching hospital. Completeness of data entry was assessed. All patients had access to a translator and clinic nurse to help complete the questionnaire if needed.

There were 34 males and 51 females (age range 16 to 81, average 48). Thirty seven patients were White British, 22 other and 26 undisclosed ethnicities. Thirty eight (45%) forms were complete leaving 47 (55%) which had at least one question unanswered or spoiled. Of these, two had five to ten errors, one had 10 to 15 errors, four had 15 to 20 errors, seven had 20 to 25 errors, ten had 25 to 30 errors and 17 had 30 to 35 errors. In addition six forms were entirely incomplete beyond patient identifier information. White British patients had fewer errors (average 4) compared to other (9) and unknown (9) ethnicities.

Outside the context of a research study, the SF-36 questionnaire in an urban teaching hospital spinal outpatient clinic is not a reliable tool. Redesign of the questionnaire may be required. The SF-36 questionnaire is less well completed by patients declared as non White British, even with the facility for a clinic nurse and a translator.

The aim of the study was to assess the safety of a novel anatomical landmark in the placement of thoracic pedicle screws. It is our clinical observation that the sagittal plane of the screw trajectory is perpendicular to the plane of the superior articular facet, when the entry point is in the lateral half of the articular surface of the corresponding superior facet.

Using SECTRA software on a PACS digital imaging system, morphometric analysis was performed on thoracic vertebrae imaged using computed tomography (CT). For inclusion, the scan had to have no reported bony abnormality. It was determined whether a trajectory as described at 90 degrees to the articular facet, with an entry point just caudal to the lateral half of the facet to a depth of 25mm would breach either the medial wall of the pedicle or lateral vertebral body wall anterior to the costovertebral facet.

Sixty-two CT scans (744 segments, 1488 pedicle-facet complexes) were reviewed. 1154 complexes were suitable for full analysis. Exclusions were due to the lumbarisation of the T12 facet joints (62) or inability to clearly define the facet surface due to the plane of the CT slice (272). Of 1154 entry points assessed, 1154 (100%) were safe to be entered at 90 degrees to a depth of at least 25mm.

We have demonstrated the safety and reliability of a novel anatomical landmark in normal thoracic pedicles. We believe this will improve sagittal plane alignment and reduce further the risk of medial pedicle breach.

Acute osteoporotic vertebral compression fractures (VCFs) are frequently misdiagnosed as there is often no history of preceding trauma. VCFs not only cause back pain, but can also result in a loss of function, spinal deformity and increased mortality. Cement augmentation has been shown to effectively treat these fractures. It is impossible to diagnose an acute fracture on plain x-ray and therefore identify those likely to benefit from this treatment. The definitive investigation to determine the presence of an acute fracture is a MR scan, but this is a limited resource. The aim of this paper is to evaluate 2 new clinical signs which we believe aid in the diagnosis of an acute VCF: firstly closed fist percussion at the level of an acute VCF resulting in a severe, sharp fracture pain, and secondly the inability of a patient to lie supine. This was a prospective study of 78 patients with suspected acute VCFs.

48/78 had an acute fracture on MR. 42/45 patients who were positive for closed fist percussion, had an acute fracture on their MR scan. There were 6 patients who were negative for closed fist percussion who had an acute fracture (sensitivity 87.5%, specificity 90%).

39/41 patients who were positive for the supine sign had an acute fracture on their MR scan. There were 9 patients who were comfortably able to lay supine who had an acute fracture (sensitivity 81.25%, specificity 93.33%).

Either a positive closed fist percussion sign or a positive supine sign is a reliable indicator of the presence of an acute VCF. By incorporating these signs into our routine clinical assessment we are better able to predict which patients have an acute fracture, and therefore decide which patients need a MR scan.

Objective: In 1989 Mirels published a scoring system for identifying impending pathological fractures in long bones, and it is now standard practice that long bones with metastases at risk of fracture are treated with prophylactic internal fixation. The spine is the most common site of skeletal metastases, with spinal metastases present in up to 36% of patients with terminal cancer. A pathological fracture through a vertebral body can result in paralysis, incontinence and severe pain. However, there is no equivalent of the Mirels’ scoring system to aid the spinal surgeon in determining the probability of an impending spinal fracture.

A weighted scoring system is proposed to quantify the risk of sustaining a pathological fracture through a metastatic lesion in a vertebral body. This system analyzes and combines four magnetic resonance (MR) risk factors into a single score.

Methods: A retrospective analysis of 100 vertebral body metastatic lesions was carried out. The original MR scans were scored, and the subsequent imaging was used to identify which vertebral body lesions fractured. Patients with no subsequent imaging within 12 months were excluded.

Results: Twenty of the 100 lesions fractured within 12 months. A mean score of 0.64 was identified in the non-fracture group, where as the fracture group had a mean score of 6.80. The percentage risk of a lesion sustaining a pathological fracture was calculated for any given score. As the score increased above 3, so did the percentage risk of fracture (sensitivity 90%, specificity 91%).

Conclusions: The authors propose that all painful vertebral body metastatic lesions be evaluated by MR scanning. Lesions with a score of 2 or less can be left untreated, while lesions with scores of 3 or higher should be considered for prophylactic balloon kyphoplasty.

Introduction: Atlanto-Occipital dislocation is rare and usually fatal. Stabilisation is typically from Occiput to C2; sacrificing atlantoaxial movement. To preserve movement, screw fixation from the articular mass of C1 to the occipital condyle has been described. Amongst other structures, the hypoglossal nerve is at risk. No previous study has addressed the anatomy of the hypoglossal canal in relation to screw trajectory. We aim to identify landmarks to aid safe screw passage into the occipital condyle.

Methods: 20 dry skulls provided 40 hypoglossal canals (HCs) and 40 occipital condyles (OCs). No distinction was made between sex, race or age. 9 parameters were measured for each HC, and relation to skull base was noted.

Results: The mean length of the HC was 10mm (range 8 to 14). The extra-cranial foramen of the HC is located lateral to the intra-cranial foramen (30° range 19 to 45). 19 out of 20 skulls had HCs with intra-cranial foramina more caudal than their extra-cranial foramina, ie the HC angled cranially (22° range 7 to 51). 36 of 40 OCs were found to be wholly inferior to the rim of the foramen magnum, with 4 (in 2 skulls) whose bodies lay largely below, but extended above, this landmark. Every single HC studied was situated, in its entirety, superior to the rim of the foramen magnum.

Conclusions: The trajectory of the hypoglossal canal from its intra-cranial foramen is antero-supero-lateral. It is situated, in its entirety, superior to the rim of the foramen magnum. The thickest portion of the occipital condyle is antero-medial. Screw passage from posterior through the C1 articular mass ought to aim for the anterior, superior, medial quadrant of the occipital condyle, and should not pass cranial to the rim of the Foramen Magnum in order to minimise the risk to the Hypoglossal Nerve.

Introduction: Cervical spine pedicle morphology has been assessed by direct measurement and by CT in cadavers. We have assessed reproducibility and produced data for normal ranges in live subjects from the UK.

Method: 54 axial CT scans were examined. All subjects were scanned for the exclusion of fracture between December 2003 and December 2004. The digitised images were analysed on the Philips PACS system using SECTRA software. 168 individual vertebrae were assessed between C3 and C7. The following were measured; the angle of the pedicle relative to the sagittal plane, the smallest internal and external diameter, the angle of the lamina and the distance from the lateral mass to the anterior vertebral body (LMAVB) in the line of the pedicle. Reproducibility was assessed in a subset of 10 individuals with paired measures using the FDA approved formula for CV%.

Results: Angular measures had a CV% of 3.9%. The re-measurement error for distance was 0.5mm. 338 pedicles were assessed in 25 females and 29 males. Average age was 48.2 years (range 17–85). Our data from live subjects was comparable to previous cadaveric data. Mean pedicle external diameter was 4.9mm at C3 and 6.6mm at C7. Females were marginally smaller than males. Left and right did not significantly differ. Mean LMAVB was 34mm (min 21mm). In no case was the pedicle narrower than 3.2mm. Mean pedicle angle was 130 deg at C3 and 140 deg at C7.

Conclusions: CT measurement has acceptable reproducibility. Previous cadaveric measurements have been validated in live subjects in the UK. Although there is some variation in morphology, instrumentation no wider than 3.0mm and no longer than 20mm is unlikely to prove too large for an adult pedicle.

Introduction: We have assessed the clinical observation that the angle of the contralateral lamina matches the angle required from the sagittal plane for the placement of pedicle screws in the subaxial cervical spine.

Method: 54 axial CT scans were examined. All subjects were scanned for the exclusion of fracture between December 2003 and December 2004. The digitised images were analysed on the Philips PACS system using SECTRA software. 168 individual vertebrae were assessed between C3 and C7. The following were measured; the angle of the pedicle relative to the sagittal plane, the smallest internal and external diameter, the angle of the lamina and the distance from the lateral mass to the anterior vertebral body (LMAVB) in the line of the pedicle. Reproducibility was assessed in a subset of 10 individuals with paired measures using the FDA approved formula for CV%.

Results: Angular measures had a CV% of 3.9%. The re-measurement error for distance was 0.5mm. 336 pedicles were assessed in 25 females and 29 males. Average age was 48.2 years (range 17–85). Our morphologic data from live subjects was comparable to previous cadaveric data. Mean pedicle external diameter was 4.9mm at C3 and 6.6mm at C7. Females were marginally smaller than males. Left and right did not significantly differ. In no case was the pedicle narrower than 3.2mm. Mean pedicle angle was 130 deg at C3 and 140 deg at C7. The laminar angle correlated well at C3,4,5 (R2> 0.7) and was within 1 deg of pedicle angle. At C6,7 it was within 11 deg. In all cases a line parallel to the lamina provided a safe corridor of 3mm for a pedicle implant.

Conclusions: The contralateral lamina provides a reliable intraoperative guide to the angle from the sagittal plane for subaxial cervical pedicle instrumentation in adults.

Background: It has been reported that there is poor correlation between neurological injury and degree of bony retropulsion in thoracolumbar burst fractures¹. Wilcox et al² showed biomechanically that there was poor concordance between the extent of post impact spinal canal occlusion and the maximum amount of occlusion that occurred at the moment of impact. In the current study we examined the possibility that variation in the termination of the conus medullaris may offer protection from neurological injury in a proportion of these fractures.

Methods: A retrospective study was made of 39 patients (26M:13M, mean age 35.9 years, range 15 – 75 years) presenting with a single level thoracolumbar burst fracture (T12–L2) between 1998 and 2001. A whole spine MRI scan was performed on all patients and the level of the conus noted. Age, sex, injury severity score (ISS), neurological status (ASIA motor score) and the transverse spinal canal area (TSCA) of the vertebral levels either side of the fractured vertebra was measured. A predicted TSCA for the injured level was then calculated from the mean of the TSCA’s of the adjacent levels. The actual TSCA of the injured level was calculated and this enabled a percentage decrease of the TSCA to be worked out from the predicted value. Analysis was made of the presence or absence of neurological injury in relation to canal compromise and involvement of the conus.

Results: Eighteen patients with neurological compromise and 21 with intact neurology (the age and sex distribution in the two groups were similar). The mean ± SD ASIA motor score of the patients studied was 90.4 ± 23. Mean ISS was 20.2 in the neurologically injured and 10.5 in the intact (p=0.0005). Mean TSCA of the canal was 218mm² in the intact and 150mm² in the injured groups (p=0.006) and mean %TSCA was 70 and 49 respectively (p=0.007). The conus lay between T12 and L2 in all patients. When the conus lay cranial to the fracture (n=13), 38% were neurologically intact. When the conus lay at the level of the fracture (n=26), 62% were intact (NS). Neurological deficit did not occur in the absence of neurological compression on MRI.

Conclusion: Our study showed that the risk of neurological injury from a thoracolumbar burst fracture was not decreased when the conus lay outside the fracture zone. However, there was a statistically significant difference in percentage of canal compromise when the patients with neurological impairment were compared with those that were neurologically intact.

Background: The incidence of neurological symptoms due to spinal stenosis in patients with achondroplasia is reported to be as great as 38%¹. These symptoms most commonly occur in the 4^th decade and myelography and CT myelography are most commonly described in evaluation of the stenosis. Difficulty arises in localisation of stenosis in patients presenting with neurological deficit². The value of MRI of the cervicomedullary junction has been reported in achondroplasia but it has not yet been evaluated in the investigation of spinal stenotic symptoms. The aim of this study was to review our experience of whole spine imaging in patients with achondroplasia that presented with symptoms and signs of neurological deficit.

Methods: We retrospectively reviewed the clinical notes and radiological imaging of 10 consecutive achondroplastic patients (3F:7M, mean age 31.7 years, range 13 to 60yrs) that presented to our unit with neurological compromise between 1998 and 2003. All patients had whole spine MRI at the time of presentation. Recorded from the notes were age and sex, and whether symptom pattern was radiculopathy, claudication or paresis. All radiological levels of stenosis on MRI were documented.

Results: Four patients presented with spinal paresis, four with neurogenic claudication, and two with radiculopathy. MRI confirmed that each patient had at least one region (cervical, thoracic or lumbar) of significant spinal stenosis. In six of the patients an additional region of significant stenosis was identified. All ten patients had lumbar stenosis but this was only the primary site in six of the ten. In the other four patients two had the dominant stenosis in the thoracic spine, one in the cervical spine and one at the foramen magnum – the clinical symptoms correlated with the dominant site in each of these four cases.

Conclusion: MRI was a useful tool for assessment of neurological compromise in the patients with achondroplasia in our study. All ten patients had classical lumbar stenosis on MRI but this was only the dominant site of stenosis in six of the ten cases. The MRI and clinical findings need to be evaluated together to ensure correct surgical treatment.

Introduction: The poor correlation between neurological injury and degree of retropulsion in thoracolumbar burst fractures has been identified, but not adequately explained. We have examined the possibility that variation in the termination of the conus medullaris may offer protection from neurological injury in a proportion of these fractures.

Methods: A retrospective study was made of 39 patients presenting with single level thoracolumbar burst fractures between June 1998 and April 2001. Admission MRI was performed on all patients. Age, sex, ISS, neurological status, mode of treatment and any neurological recovery were recorded. From the MRI scans the levels of the conus and the fracture were noted. Transverse Spine Area(TSA) was measured at the cranial, caudal and injured levels. A predicted TSA and % TSA for the injury level was calculated from the mean of the two other levels. Analysis was of severity of neurological injury in relation to canal compromise and involvement of the conus.

Results: 26 male and 13 female patients of mean age 35.9 (SD 17) years and mean ASIA motor score 90.4 (SD 23) were studied. Neither sex nor age distribution differed between 18 neurologically injured and 21 intact patients. Mean ISS was 20.2 in the neurologically injured and 10.5 in the intact (p=0.0005). Mean TSA of the canal was 218mm2 in the intact and 150mm2 in the injured groups (p=0.006) and mean %TSA was 70 and 49 respectively (p=0.007). The conus lay between T12 and L2 in all. When the conus lay cranial to the fracture (n=13), 38% were neurologically intact. When the conus lay at the level of the fracture (n=26), 62% were intact (NS). Neurological deficit did not occur in the absence of neurological compression on MRI.

Conclusions: Neurological injury is not less likely when the conus lie outside the fracture zone. Canal compromise is a highly significant factor in neurological injury.

Study Design: A retrospective case-note study.

Objective: To evaluate causes of delayed admission for patients with spinal injuries.

Subjects: 432 patients admitted between March 1998 and March 2003.

Outcome Measures: Patients were analysed with respect to Injury Severity Score (ISS); date of injury, referral and admission independently and length of hospitalisation. The delays between injury and referral (> 3 days) and between referral and admission (> 7days) were correlated to the length of hospitalisation.

Results: There were 322 males (average age, 38.6 years) and 110 females (average age, 41.8 years), with 108 complete injuries, 115 incomplete and 209 intact. The average time between injury and referral was 5.5 days (range 0–94), and between referral and admission was 10.7 days (range 0–130). 161 patients (37%) experienced a delay between injury and referral, of whom 59 (37%) were subsequently also delayed to admission. The principal reason for delay was the treatment of concurrent injuries. Even patients with complete injuries (15/43) experienced delayed referral. 112 patients (26%) experienced a delay between referral and admission. Principal reasons included the provision of beds and stabilisation of concurrent injuries. We found the delay between referral and admission (p< 0.001), the ISS (p< 0.001) and increasing neurological severity of injury (p< 0.001) to be highly significant factors predisposing to longer hospitalisation.

Conclusions: Delayed admission for patients with spinal injuries is common. Provision of beds being the most common preventable reason for delay following referral. Early liason with a designated spinal injuries unit, especially for patients with cord injury remains vitally important.

Purpose: We present a new basilar osteotomy we have called TRADE. This osteotomy uses a single flat-oblique cut to achieve lateral basimetatarsal translation with lowering and derotation.

Material: The ATLAS system was used. This system includes a four point axial staple for the phalanx and a staple plate for the metatarsus. The staple plaque was designed around the tibial osteotomy plates. It is composed of a straight plate screwed to the diaphysis. It carries two spikes at variable angles that penetrate the epiphysis perpendicularly. The desired angle is measured peroperatively and the plate is bent appropriately using a graduated template. Application of the staple plate then imposes the exact correction.

Method: We tested the basal osteotomy on five anatomic hallux valgus specimens, including one fresh specimen. We also reviewed 125 files of patients who underwent double flat-oblique osteotomy fixed with the system. Each type of hallux valgus was defined pre- and postoperatively, clinically and radiologically: four views, three to determine the orientation of the deformity in the three planes and a fourth one to assess reducibility. The operative technique involved four times. The first was often not necessary: lateral release, depending on the degree of retraction on the reduction view. The second time, the medial chevron osteotomy of the first phalanx, was almost always needed. The third time was the basimetatarsal ostetomy; the flat-oblique direction was determined from an abacus taking into account three variables: varus, rotation, lowering. The fourth time, exostosectomy with capsule retention, was not always needed. The patients experienced little pain postoperatively when the procedure was limited to the two osteotomies without affecting the soft tissues. For the 125 cases, intermetatarsal deviation was improved from 18°67 to 6°86, metatarsophalangeal angle from 33°59 to 11° and pronation from 13°42 to 0°72.

Conclusion: The TRADE osteotomy allows correction in all three planes. Correction is particularly precise in the frontal plane where the risk of undercorrection and recurrence is high. The procedure can be modulated according to the radiological presentation and can be limited to two osteotomies using short skin incisions without opening the joint.

Purpose: All displacements can be described with x, y, z coordinates. We propose an anterior view of the first metatarsal associated with a peroperative test to determine the precise position in the frontal plane, both statically and dynamically. Lateral release is an important step in surgical treatment of hallux valgus. Both the extent of release and the potential benefit of no release must be carefully evaluated. We propose a view allowing an assessment of the metatarsophalangeal reducibility.

Material and method: Peroperative test. This test explores cuneometatarsal laxity. We conducted a prospective study in 100 cases. A 12/100 pin was used to immobilise the first cuneiform and a 20/100 pin was placed in the base of the first metatarsal. A third distal pin in the neck was used to pivot the bone on its axis. A small protractor was used to measure the angle by projection with ±2.5° precision.

Modified Guntz view. This is a weight-bearing anterior view of the first metatarsal. The cassette is positioned posteriorly. The patient stands with the heal raised 40 mm on a 20mmx20mm plexiglass bar. The metatarsal diaphysis must appear perfectly vertical. An isosceles triangle is constructed on the articular facets; the base of the triangle is perfectly horizontal and defines the pronation-supination angle. We made 100 measurements and checked correlation with the peroperative test.

Reduction view. A Zimmer brace was used to reduce the varus metatarsus and adduct the toe. The metatarsophalangeal angle and the position of the sesamoids were used to assess reducibility.

Results: Pronation and/or pronation instability was = 10° in 96% of the patients. The reduction view enabled classifiation by three grades of reducibility.

Discussion: Our contribution is determining for correction of displacements taking into account the frontal plane. No other study has shown so clearly the existence of metatarsal pronation. We also confirmed the presence of a large proportion of cuneometatarsal instability. The extent of lateral release or the potential benefit of no release can now be assessed.

Conclusion: A certain number of failures have undoubtedly been related to neglect of the parameters studied here. It is indispensable to explore the frontal plane and the dynamic parameters before establishing indications for new flat-oblique metatarsal osteotomies using conventional or minimally invasive techniques.