Plain radiography has traditionally been used to investigate and monitor patients with adolescent idiopathic scoliosis. The X-ray allows a calculation of the Cobb angle which measures the degree of lateral curvature in the coronal plane. ISIS2 is a surface topography system which has evolved from ISIS, but with much higher precision and speed. It measures the three dimensional shape of the back using structured light and digital photography. This system has the benefit of not requiring any radiation. Lateral asymmetry is the ISIS clinical parameter estimating the curve of the spine in the coronal plane. The aim of this study was to compare this parameter to the Cobb angle measured on plain X-ray. Twelve patients with idiopathic adolescent scoliosis underwent both a standing AP spine X-ray and an ISIS2 scan on multiple occasions. Both scan and X-ray were done within one month of each other. No patient underwent surgery during the study period. The Cobb angle and the degree of lateral asymmetry were calculated. Twelve patients mean age 12.5 years (range 10-16) were investigated using both ISIS2 and X-ray. They had a mean 2.3 (1-5) combined investigations allowing for 30 comparisons. The correlation between the two measurements was r =0.63 (p=0.0002). The Cobb angle measured on ISIS2 was less than that measured by radiograph in 27 out of 30 comparisons. The mean difference between the measurements was mean 6.4° with a standard deviation of 8.2° and 95% confidence interval of 3.3° to 9.4°. In adolescent idiopathic scoliosis, curve severity and rib hump severity are related but measure different aspects of spinal deformity. As expected, these relate closely but not precisely. ISIS2 offers the promise of monitoring scoliosis precisely, without adverse effects from radiation. The small numbers in this series focus on the group of patients with mild to moderate curves at risk of progression. In this group, ISIS2 was able to identify curve stability or progression, without exposing the subjects to radiation

To evaluate and describe the plain radiographic changes observed with time in fusions using SiS-CaP. We describe, for the first time, 4 stages of bone substitute fusion mass (BSFM) radiographic appearance in relation to time post-op. Retrospective, radiological evaluation. Over 200 plain radiographs were evaluated. 70 consecutive fusions for degenerative spinal stenosis were included, in all cases performed by the same surgeon using the same operative technique. Follow-up was from 3 months to 2 years post-op. Radiographs were evaluated for the presence or absence of SiS-CaP granules, bone formation and for evidence of pseudarthrosis. Trends were seen within the BSFM with respect to time. At 6-12 weeks post-op a ‘homogenous granular stage’ indicates the presence of the unchanged SiS-CaP. At 12 weeks, small pockets appear within the BSFM in the ‘vacuolation stage’, indicating bioresorption of the graft. Vacuoles become increasingly radio-opaque indicating bone proliferation during the ‘homogenous lamellar stage’. At variable time between 6 months and 2 years, the BSFM becomes encapsulated in the ‘cortication stage’ visible as a sclerotic rim around the BSFM. We have seen a clear trend in the behaviour of the fusion mass in this case series. The radiological stages we have described above can be closely correlated with previously reported in-vitro and in-vivo studies looking at the micro-function of SiS-CaP. We hope that this description will help to judge the progress of graft incorporation and fusion. Further study of inter and intra-observer correlation will be required

Aims. The aim of this study was to compare the clinical and radiological outcomes of patients with early-onset scoliosis (EOS), who had undergone spinal fusion after distraction-based spinal growth modulation using either traditional growing rods (TGRs) or magnetically controlled growing rods (MCGRs). Methods. We undertook a retrospective review of skeletally mature patients who had undergone fusion for an EOS, which had been previously treated using either TGRs or MCGRs. Measured outcomes included sequential coronal T1 to S1 height and major curve (Cobb) angle on plain radiographs and any complications requiring unplanned surgery before final fusion. Results. We reviewed 43 patients (63% female) with a mean age of 6.4 years (SD 2.6) at the index procedure, and 12.2 years (SD 2.2) at final fusion. Their mean follow-up was 8.1 years (SD 3.4). A total of 16 patients were treated with MCGRs and 27 with TGRs. The mean number of distractions was 7.5 in the MCGR group and ten in the TGR group (p = 0.471). The mean interval between distractions was 3.4 months in the MCGR group and 8.6 months in the TGR group (p < 0.001). The mean Cobb angle had improved by 25.1° in the MCGR group and 23.2° in TGR group (p = 0.664) at final follow-up. The mean coronal T1 to S1 height had increased by 16% in the MCGR group and 32.9% in TGR group (p = 0.001), although the mean T1 to S1 height achieved at final follow-up was similar in both. Unplanned operations were needed in 43.8% of the MCGR group and 51.2% of TGR group (p = 0.422). Conclusion. In this retrospective, single-centre review, there were no significant differences in major curve correction or gain in spinal height at fusion. Although the number of planned procedures were fewer in patients with MCGRs, the rates of implant-related complications needing unplanned revision surgery were similar in the two groups. Cite this article: Bone Joint J 2022;104-B(2):257–264

The purpose of this study was to devise a simple but reliable radiological method of identifying a lumbosacral transitional vertebra (LSTV) with a solid bony bridge on sagittal MRI, which could then be applied to a lateral radiograph.

The vertical mid-vertebral angle (VMVA) and the vertical anterior vertebral angle (VAVA) of the three most caudal segments of the lumbar spine were measured on MRI and/or on a lateral radiograph in 92 patients with a LSTV and 94 controls, and the differences per segment (Diff-VMVA and Diff-VAVA) were calculated. The Diff-VMVA of the two most caudal vertebrae was significantly higher in the control group (25° (sd 8) than in patients with a LSTV (type 2a+b: 16° (sd 9), type 3a+b: -9° (sd 10), type 4: -5° (sd 7); p < 0.001). A Diff-VMVA of ≤ +10° identified a LSTV with a solid bony bridge (type 3+4) with a sensitivity of 100% and a specificity of 89% on MRI and a sensitivity of 94% and a specificity of 74% on a lateral radiograph. A sensitivity of 100% could be achieved with a cut-off value of 28° for the Diff-VAVA, but with a lower specificity (76%) on MRI than with Diff-VMVA.

Using this simple method (Diff-VMVA ≤ +10°), solid bony bridging of the posterior elements of a LSTV, and therefore the first adjacent mobile segment, can be easily identified without the need for additional imaging.

Cite this article: Bone Joint J 2013;95-B:1533–7.

Aims. To benchmark the radiation dose to patients during the course of treatment for a spinal deformity. Methods. Our radiation dose database identified 25,745 exposures of 6,017 children (under 18 years of age) and adults treated for a spinal deformity between 1 January 2008 and 31 December 2016. Patients were divided into surgical (974 patients) and non-surgical (5,043 patients) cohorts. We documented the number and doses of ionizing radiation imaging events (radiographs, CT scans, or intraoperative fluoroscopy) for each patient. All the doses for plain radiographs, CT scans, and intraoperative fluoroscopy were combined into a single effective dose by a medical physicist (milliSivert (mSv)). Results. There were more ionizing radiation-based imaging events and higher radiation dose exposures in the surgical group than in the non-surgical group (p < 0.001). The difference in effective dose for children between the surgical and non-surgical groups was statistically significant, the surgical group being significantly higher (p < 0.001). This led to a higher estimated risk of cancer induction for the surgical group (1:222 surgical vs 1:1,418 non-surgical). However, the dose difference for adults was not statistically different between the surgical and non-surgical groups. In all cases the effective dose received by all cohorts was significantly higher than that from exposure to natural background radiation. Conclusion. The treatment of spinal deformity is radiation-heavy. The dose exposure is several times higher when surgical treatment is undertaken. Clinicians should be aware of this and review their practices in order to reduce the radiation dose where possible. Cite this article: Bone Joint J 2021;103-B(4):1–7

Introduction. Pulmonary Tuberculosis (TB) can be detected by sputum cultures. However, Extra Pulmonary Spinal Tuberculosis (EPSTB), diagnosis is challenging as it relies on retrieving a sample. It is usually discovered in the late stages of presentation due to its slow onset and vague early presentation. Difficulty in detecting Mycobacterium Tuberculosis bacteria from specimens is well documented and therefore often leads to culture negative results. Diagnostic imaging is helpful to initiate empirical therapy, but growing incidence of multidrug resistant TB adds further challenges. Methods. A retrospective analysis of cases from the Infectious Disease (ID) database with Extra Pulmonary Tuberculosis (EPTB) between 1. st. of January 2015 to 31. st. of January. Two groups were compared 1) Culture Negative TB (CNTB) and 2) Culture Positive TB (CPTB). Audit number was. Results. 31 cases were identified with EPSTB. 68% (n=21) were male. 55% (n=17) patients were Asian, (19% (n=6) were black and 16% (n=5) were of white ethnicity. 90.4% (n=28) patients presented with isolated spinal TB symptoms. No patient had evidence of HBV/HCV/HIV infections. CPTB Group was 51.6% (n=16) compared to CNTB Group with 48.4% (n=15) 48% (15) lumbar involvement, 42% (13) thoracic and 10% (3) cervical. 38.7% (12) patients presented with late neurology, equally in both groups. 56% CPTB patients showed signs of vertebral involvement on plain radiograph compared to 13.3% in CNTB patients. 68.7% CPTB patients had pathological changes or paraspinal collections seen on CT scan compared to 53.3% of CNTB patients. 81% of CPTB showed positive MRI findings compared to 86% in CNTB. Both groups were treated with Anti-TB medications according to local guidelines. 83% patients were followed up till the end of the treatment course. 22.5% (n=7) patients had Ultrasound guided aspiration. 29% (n=9) patients underwent surgical intervention. 3 patients had Laminectomy for decompression. 6 patients underwent Spinal Decompression and Fixation due to extensive bone destruction. No mortality occurred. Conclusion. TB continues to be a growing problem in the developed world with high numbers of patients travelling from endemic regions. 75% of our cases were from Asian or Black ethnicity. The thoracolumbar region was most commonly effected (90%). Approximately 50% of cases of extrapulmonary spinal TB were culture negative. Neurological deficit occurred in 40% patients and 30% of patients required surgery. Standard anti-TB treatment was however effective in all cases with no significant drug resistant variants noted. MRI and CT imaging remain the superior diagnostic tests in the presence of high CN EPSTB

Purpose and background. Static plain radiographs at the end of uncontrolled bending are the current standard of care for measuring translatory slip in back pain patients. Quantitative fluoroscopy systems (QF) that employ standardised bending protocols have been found to improve precision and reduce dose, but comparative data are lacking. We compared 4 QF methods with static radiographs in a control population, calculating ranges, population variation and measurement errors over 6 weeks. Methods. Fifty-four healthy controls (F=22, M=23) received passive recumbent and active weight bearing QF screenings during controlled motion, plus still fluoro imaging in neutral, flexion and extension. The translatory slip of all levels from L2-S1 was determined for each condition using bespoke image tracking codes (Matlab) and pooled to provide means and ranges of variation (+/-1.96SD). The pooled measurement error, or minimal detectable change (MDC. 95. ), reflecting the intra subject repeatability over 6 weeks was calculated. Ranges of translation for each level (L2-S1), for each type of motion were also calculated. Results. Static radiographs at the end of uncontrolled flexion gave the greatest variation and the worst repeatability, while QF recumbent passive and active weight bearing motion with flexion recorded during the motion had ¼ less variation and twice the repeatability. For individual levels, L2-3 had significantly higher flexion ranges in controlled motion than uncontrolled motion, whereas the converse was true at L4-5 (P<0.001). Conclusion. Dynamic QF measurement of flexion translatory slip gives ¼ less population variation and half the measurement error of static radiographs when measured in the same participants. No conflicts of interest. No funding obtained

Aims. To address the natural history of severe post-tuberculous (TB) kyphosis, with focus upon the long-term neurological outcome, occurrence of restrictive lung disease, and the effect on life expectancy. . Patients and Methods. This is a retrospective clinical review of prospectively collected imaging data based at a single institute. A total of 24 patients of Southern Chinese origin who presented with spinal TB with a mean of 113° of kyphosis (65° to 159°) who fulfilled inclusion criteria were reviewed. Plain radiographs were used to assess the degree of spinal deformity. Myelography, CT and MRI were used when available to assess the integrity of the spinal cord and canal. Patient demographics, age of onset of spinal TB and interventions, types of surgical procedure, intra- and post-operative complications, and neurological status were assessed. . Results. All except one of the 24 patients were treated with anti-TB chemotherapy when they were first diagnosed with spinal TB. They subsequently received surgery either for neurological deterioration, or deformity correction in later life. The mean follow-up was 34 years (11 to 59) since these surgical interventions. Some 16 patients (66.7%) suffered from late neurological deterioration at a mean of 26 years (8 to 49) after the initial drug treatment. The causes of neurological deterioration were healed disease in nine patients (56.2%), re-activation in six patients (37.5%) and adjacent level spinal stenosis in one patient (6.3%). The result of surgery was worse in healed disease. Eight patients without neurological deterioration received surgery to correct the kyphosis. The mean correction ranged from 97° to 72°. Three patients who were clinically quiescent with no neurological deterioration were found to have active TB of the spine. Solid fusion was achieved in all cases and no patient suffered from neurological deterioration after 42 years of follow-up. On final follow-up, six patients were noted to have deceased (age range: 47 years to 75 years). Conclusion. Our study presents one of the longest assessments of spinal TB with severe kyphosis. Severe post-TB kyphosis may lead to significant health problems many years following the initial drug treatment. Early surgical correction of the kyphosis, solid fusion and regular surveillance may avoid late complications. Paraplegia, restrictive lung disease and early onset kyphosis might relate to early death. Clinically quiescent disease does not mean cure. . Cite this article: Bone Joint J 2017;99-B:1381–8

The ratio of the sagittal diameter of the cervical canal to the corresponding diameter of the vertebral body has been described as a reliable means for assessing stenosis of the canal and detecting those at risk of cervical neuropraxia. The use of ratio techniques has the advantage of avoiding variation in magnification when direct measurements are made from plain radiographs. We examined the reliability of this method using plain lateral radiographs of unknown magnification and CT scans. We also assessed other possible ratios of anatomical measurements as a guide to the diameter of the canal. Our findings showed a poor correlation between the true diameter of the canal and the ratio of its sagittal diameter to that of the vertebral body. No other more reliable ratio was identified. The variability in anatomical morphology means that the use of ratios from anatomical measurements within the cervical spine is not reliable in determining the true diameter of the cervical canal

We evaluated the efficacy of Escherichia coli-derived recombinant human bone morphogenetic protein-2 (E-BMP-2) in a mini-pig model of spinal anterior interbody fusion. A total of 14 male mini-pigs underwent three-level anterior lumbar interbody fusion using polyether etherketone (PEEK) cages containing porous hydroxyapatite (HA). Four groups of cages were prepared: 1) control (n = 10 segments); 2) 50 μg E-BMP-2 (n = 9); 3) 200 μg E-BMP-2 (n = 10); and 4) 800 μg E-BMP-2 (n = 9). At eight weeks after surgery the mini-pigs were killed and the specimens were evaluated by gross inspection and manual palpation, radiological evaluation including plain radiographs and micro-CT scans, and histological analysis. Rates of fusion within PEEK cages and overall union rates were calculated, and bone formation outside vertebrae was evaluated. One animal died post-operatively and was excluded, and one section was lost and also excluded, leaving 38 sites for assessment. This rate of fusion within cages was 30.0% (three of ten) in the control group, 44.4% (four of nine) in the 50 μg E-BMP-2 group, 60.0% (six of ten) in the 200 μg E-BMP-2 group, and 77.8% (seven of nine) in the 800 μg E-BMP-2 group. Fusion rate was significantly increased by the addition of E-BMP-2 and with increasing E-BMP-2 dose (p = 0.046). In a mini-pig spinal anterior interbody fusion model using porous HA as a carrier, the implantation of E-BMP-2-loaded PEEK cages improved the fusion rate compared with PEEK cages alone, an effect that was significantly increased with increasing E-BMP-2 dosage. Cite this article: Bone Joint J 2013;95-B:217–23

The presacral retroperitoneal approach for axial lumbar interbody fusion (presacral ALIF) is not widely reported, particularly with regard to the mid-term outcome. This prospective study describes the clinical outcomes, complications and rates of fusion at a follow-up of two years for 26 patients who underwent this minimally invasive technique along with further stabilisation using pedicle screws. The fusion was single-level at the L5-S1 spinal segment in 17 patients and two-level at L4–5 and L5-S1 in the other nine. The visual analogue scale for pain and Oswestry Disability Index scores were recorded pre-operatively and during the 24-month study period. The evaluation of fusion was by thin-cut CT scans at six and 12 months, and flexion-extension plain radiographs at six, 12 and 24 months. Significant reductions in pain and disability occurred as early as three weeks postoperatively and were maintained. Fusion was achieved in 22 of 24 patients (92%) at 12 months and in 23 patients (96%) at 24 months. One patient (4%) with a pseudarthrosis underwent successful revision by augmentation of the posterolateral fusion mass through a standard open midline approach. There were no severe adverse events associated with presacral ALIF, which in this series demonstrated clinical outcomes and fusion rates comparable with those of reports of other methods of interbody fusion

We reviewed 15 consecutive patients, 11 women and four men, with a mean age of 48.7 years (37.3 to 62.6), who between July 2004 and August 2007 had undergone percutaneous sacroiliac fusion using hollow modular anchorage screws filled with demineralised bone matrix. Each patient was carefully assessed to exclude other conditions and underwent pre-operative CT and MR scans. The diagnosis of symptomatic sacroiliac disease was confirmed by an injection of local anaesthetic and steroid under image intensifier control. The short form-36 questionnaire and Majeed’s scoring system were used for pre- and post-operative functional evaluation. Post-operative radiological evaluation was performed using plain radiographs. Intra-operative blood loss was minimal and there were no post-operative clinical or radiological complications. The mean follow-up was for 17 months (9 to 39). The mean short form-36 scores improved from 37 (23 to 51) to 80 (67 to 92) for physical function and from 53 (34 to 73) to 86 (70 to 98) for general health (p = 0.037). The mean Majeed’s score improved from 37 (18 to 54) pre-operatively to 79 (63 to 96) post-operatively (p = 0.014). There were 13 good to excellent results. The remaining two patients improved in short form-36 from a mean of 29 (26 to 35) to 48 (44 to 52). Their persistent pain was probably due to concurrent lumbar pathology. We conclude that percutaneous hollow modular anchorage screws are a satisfactory method of achieving sacroiliac fusion

This study evaluates factors related to myelopathic symptoms in patients with ossification of the posterior longitudinal ligament (OPLL). A total of 87 patients with OPLL were included. Of these, 53 (Group I) had no symptoms or presented with neck pain and radiculopathy and 34 (Group II) had myelopathic symptoms. Gender, age, and history of trauma were evaluated in the two groups. The range of movement of the cervical spine was measured using plain radiographs. The number of involved segments, type of OPLL, and maximal compression ratio were analysed using CT and signal change in the spinal cord was evaluated using MRI. The patients’ age was found to be significant (p = 0.001). No difference was found between gender and the range of movement in the two groups. The maximum compression of the spinal canal showed a difference (p = 0.03). The signal change of the spinal cord was different between the two groups. In patients with OPLL of the cervical spine, myelopathic symptoms are not related to the range of movement or the number of involved segments.

Background. The factors influencing normal spine curvature in midlife are unknown. We performed an MR and plain radiograph study on well characterised, unselected twin volunteers from the TwinsUK register (. www.twinsuk.ac.uk. ) to determine the relative contributions of genetic and environmental factors to spine curve. Methods. T2 weighted MR scans and long spine standing radiographs were obtained at the same morning visit on twin pairs. Midline sagittal MR images were coded for 4 degenerative features. SpineviewTM software was applied plain films and calculated the angles of curvature. A classical twin study was performed. Multivariate regression analysis was used to determine the association between spine curves, LDD and confounders (age, body mass index). Results. Data were available on 110 monozygotic (MZ) and 136 dizygotic (DZ) female twins. Mean age was 64.3 years (range 40.1–79.3); age was associated with increasing lumbar lordosis (p=0.02). The AE model (comprising additive genetic and unique environmental factors) was the most suitable model for both lumbar lordosis and thoracic kyphosis (as determined by Akaike information criterion). Heritability estimates = 59% (42–71%) for lumbar lordosis; and 61% (46–74%) for thoracic kyphosis. After adjusting for age and BMI, lumbar lordosis was significantly associated with a number of features of LDD (p<0.001) including disc signal intensity and osteophytes. Conclusion. The twins are known to be representative of women in the general population. Lumbar lordosis and thoracic kyphosis of the spine have considerable heritable component in females suggesting that a search for individual gene variants would be a reasonable next step. This abstract was presented at 14th Congress of the International Society for Twin Studies. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained

A four-year-old boy presented with a solitary bone cyst in the odontoid process and body of the axis. Plain radiographs showed a radiolucent lesion with extreme thinning of the cortex and MRI demonstrated a high signal intensity in the interlesional matrix. The cystic component extended into the body of the axis through a defect in the epiphyseal plate. At operation, the cavity of the cyst was found to contain serosanguineous fluid, and histological examination showed that it was lined by a thin layer of connective tissue. The cyst may have originated from a defect in the epiphyseal plate

Background. Rotatory subluxation of the atlantoaxial joint has been thoroughly documented in children. However, pure traumatic atlantoaxial rotatory subluxation (TAARS) is a rare injury in adults with only a few cases reported in the English literature. Aim. To report two cases of TAARS in adults. Methods. A case note, clinical and radiological review. Results. Both patients were female. There was a history of a motor vehicle collision in both cases. There was no neurological impairment at presentation in either case. The injury in both cases was identified by plain X-ray and confirmed by CT scan. Both were managed by conservative treatment, initially with halo traction, followed by immobilisation in a rigid collar. Final clinical reviews occurred at 7 years and 2.5 years following injury. Neither patient had signs of C1-C2 instability or impaired neurology. Both patients, however, suffered headaches and occipital neuralgia, with stiffness and reduction in cervical spine movement. Conclusion. Traumatic rotatory subluxation in adults is a rare injury. It can pose a diagnostic challenge and CT scanning is mandatory for a correct evaluation of the C1-2 complex. Reduction and stability can be achieved through conservative treatment. However, it is evident from this short series that even early diagnosis and prompt reduction may not necessarily result in a good long term outcome in adult patients with TAARS

Spinal disc infection is associated with a significant morbidity and mortality in the acute setting. On long term review it leads to significant moribidity due to the deformity and secondary osteoarthritic changes in the surrounding vertebral segments. Prospective collection of data of 21 patients suffering from discitis was collected over the span of last 10 years. The age group ranged between 21 -67 yrs. The male: female ratio was 1.2:1. The minimum delay in presentation since the onset of symptoms was 8 weeks. The detection of the micro-organism was either by needle/open biopsy or indirectly via blood cultures. Serial records were maintained of inflammatory markers. All patients received plain radiographs, gadolinium-enhanced magnetic resonance imaging scans, and bone/gallium radionuclide studies. Operative decompression was performed in 7 patients. Infection elsewhere was the most common predisposing factor. Leukocyte counts were elevated in 54% of spondylodiscitis cases. The erythrocyte sedimentation rate and CRP were elevated in all cases of epidural abscess. The most common organism was Staph Aureus. Antibiotics were administered for duration of at least 6 weeks. On long term, all patients developed deformity at the level of the infection, with half of them being symptomatic. Spinal infections are extremely morbid conditions demanding prompt diagnosis and urgent treatment to prevent complications. Ethics approval: Audit Committee Interest statement: No conflict of interest

Objective. The purpose of this study is to describe and validate a CT based classification of lumbosacral segment abnormalities. Method. 400 CT scans were retrospectively reviewed, a classification devised and incidence of abnormalities recorded. 5 types of abnormality were identified. Type 0 is normal; Type 1 describes an asymmetrical shortening of the iliolumbar ligament; Type 2's have the transverse process of L5 within 2 mm of the sacrum but not forming a joint; Type 3's have formed a diarthrodial joint, with 3A's showing no evidence of degeneration and 3B's displaying degenerative changes; In type 4's the transverse process and sacrum have fused; Type5's have involvement of L4. In order to validate the classification, 40 scans were selected with a full cross section of types. 4 independent observers classified each scan in 2 separate sessions, 2 weeks apart. Results. In the study population there was an abnormality in 54.5% of individuals. In order to validate the classification the intra-observer and inter-observer ratings were analysed. The kappa values for the intra-observer results were between 0.69 and 0.88, indicating substantial agreement (using the Landis and Koch kappa interpretation). The results for inter-observer ratings also gave a combined score of over 0.7 for both sessions, again indicating substantial agreement. Conclusion. A CT classification of lumbosacral segment abnormalities, which is both straight forward to use and repeatable, has been produced. The incidence of these abnormalities is higher in our population of CT scans compared to previous published series using plain radiographs

The purpose of our study is to assess the degenerative changes in the motion segments above a L5S1 spondylolytic spondylolisthesis, and to analyse the factors that contribute towards a retro-listhesis in the segment immediately above the slip. Prospective radiographic case series. 38 patients with a symptomatic L5S1 spondylolytic spondylolisthesis, with a mean age of 52.8 yrs (95% CI 47.2 – 58.4). 55.3% (n = 21) were females and 44.7% (n = 17) males. 58% (22) had grade 1 and 42% (16) grade 2 slips. Plain radiographs: Lumbar lordosis, slip angle, sacral slope, grade of the slip, and retro-listhesis at L45. MRI scans: facet angles at L34 and L45, facet degenerative score at L34 and L45 (cartilage and sclerosis), disc degenerative score at L45 and L5S1 (Pfirrmann). The Pfirmann disc score for L45 was 2.75 and L5S1 4.4 (p < 0.0001); the mean facet angle at L34 50.9° and L45 57.9° (p = 0.001) and the facet score at L34 was 8 and at L45 was 10.5 (p = 0.0001). 29% (11) demonstrated a retrolithesis at L45. Analysing the effect of these factors on the causation of retro-listhesis at L45 (table) the slip angle and L45 disc degenerative score were the only factors that predicted a retro-listhesis. There is a cascade of degenerative changes involving both the disc and the facet joints at the levels above a spondylolytic spondylolisthesis. The degenerative changes at the L45 disc and a higher slip angle predict a retro-listhesis at the level above the slip

We have measured the dynamic movement of the lumbar spine in 57 patients with degenerative lumbar disc disease. Each completed a questionnaire which recorded pain and subjective signs and symptoms. From plain lateral radiographs, the subjects were graded using the criteria of Kellgren and Lawrence and those of Lane et al, which are both based on the severity of degenerative changes. Measurements of the height of the disc space and the vertebral height were obtained and expressed as a ratio. We found no relationship between the characteristics of spinal movement and the overall grading of degenerative disc disease with either system. Both were influenced (p < 0.01) by age, walking distance, severity of symptoms, drug intake and frequency of pain. The present systems for grading degenerative disc disease from plain lateral radiographs have limited application