Objectives. Many studies have investigated the kinematics of the lumbar spine and the morphological features of the lumbar discs. However, the segment-dependent immediate changes of the lumbar intervertebral space height during flexion-extension motion are still unclear. This study examined the changes of intervertebral space height during flexion-extension motion of lumbar specimens. Methods. First, we validated the accuracy and repeatability of a custom-made mechanical loading equipment set-up. Eight lumbar specimens underwent CT scanning in flexion, neural, and extension positions by using the equipment set-up. The changes in the disc height and distance between adjacent two pedicle screw entry points (DASEP) of the posterior approach at different lumbar levels (L3/4, L4/5 and L5/S1) were examined on three-dimensional lumbar models, which were reconstructed from the CT images. Results. All the vertebral motion segments (L3/4, L4/5 and L5/S1) had greater changes in disc height and DASEP from neutral to flexion than from neutral to extension. The change in anterior disc height gradually increased from upper to lower levels, from neutral to flexion. The changes in anterior and posterior disc heights were similar at the L4/5 level from neutral to extension, but the changes in anterior disc height were significantly greater than those in posterior disc height at the L3/4 and L5/S1 levels, from neutral to extension. Conclusions. The lumbar motion segment showed level-specific changes in disc height and DASEP. The data may be helpful in understanding the physiologic dynamic characteristics of the lumbar spine and in optimising the parameters of lumbar surgical instruments. Cite this article: M. Fu, Q. Ye, C. Jiang, L. Qian, D. Xu, Y. Wang, P. Sun, J. Ouyang. The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion. Bone Joint Res 2017;6:245–252. DOI: 10.1302/2046-3758.64.BJR-2016-0245.R1

Objectives. Loss of motion following spine segment fusion results in increased strain in the adjacent motion segments. However, to date, studies on the biomechanics of the cervical spine have not assessed the role of coupled motions in the lumbar spine. Accordingly, we investigated the biomechanics of the cervical spine following cervical fusion and lumbar fusion during simulated whiplash using a whole-human finite element (FE) model to simulate coupled motions of the spine. Methods. A previously validated FE model of the human body in the driver-occupant position was used to investigate cervical hyperextension injury. The cervical spine was subjected to simulated whiplash exposure in accordance with Euro NCAP (the European New Car Assessment Programme) testing using the whole human FE model. The coupled motions between the cervical spine and lumbar spine were assessed by evaluating the biomechanical effects of simulated cervical fusion and lumbar fusion. Results. Peak anterior longitudinal ligament (ALL) strain ranged from 0.106 to 0.382 in a normal spine, and from 0.116 to 0.399 in a fused cervical spine. Strain increased from cranial to caudal levels. The mean strain increase in the motion segment immediately adjacent to the site of fusion from C2-C3 through C5-C6 was 26.1% and 50.8% following single- and two-level cervical fusion, respectively (p = 0.03, unpaired two-way t-test). Peak cervical strains following various lumbar-fusion procedures were 1.0% less than those seen in a healthy spine (p = 0.61, two-way ANOVA). Conclusion. Cervical arthrodesis increases peak ALL strain in the adjacent motion segments. C3-4 experiences greater changes in strain than C6-7. Lumbar fusion did not have a significant effect on cervical spine strain. Cite this article: H. Huang, R. W. Nightingale, A. B. C. Dang. Biomechanics of coupled motion in the cervical spine during simulated whiplash in patients with pre-existing cervical or lumbar spinal fusion: A Finite Element Study. Bone Joint Res 2018;7:28–35. DOI: 10.1302/2046-3758.71.BJR-2017-0100.R1

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.

Aims. The optimal procedure for the treatment of ossification of the posterior longitudinal ligament (OPLL) remains controversial. The aim of this study was to compare the outcome of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) with posterior laminectomy and fusion with bone graft and internal fixation (PTLF) for the surgical management of patients with this condition. Methods. Between July 2017 and July 2019, 40 patients with cervical OPLL were equally randomized to undergo surgery with an ACOE or a PTLF. The clinical and radiological results were compared between the two groups. Results. The Japanese Orthopaedic Association (JOA) score and recovery rate in the ACOE group were significantly higher than those in the PTLF group during two years postoperatively, provided that the canal occupying ratio (COR) was > 50%, or the K-line was negative. There was no significant difference in JOA scores and rate of recovery between the two groups in those in whom the COR was < 50%, or the K-line was positive. There was no significant difference in the Cobb angle between C2 and C7, sagittal vertical axis, cervical range of motion (ROM), and complications between the two groups. Conclusion. Compared with PTLF, ACOE is a preferred surgical approach for the surgical management of patients with cervical OPLL in that it offers a better therapeutic outcome when the COR is > 50%, or the K-line is negative, and it also preserves better cervical curvature and sagittal balance. The prognosis of ACOE is similar to that of PTLE when the COR is < 50%, or the K-line is positive. Cite this article: Bone Joint J 2023;105-B(4):412–421

Aims

Symptomatic spinal stenosis is a very common problem, and decompression surgery has been shown to be superior to nonoperative treatment in selected patient groups. However, performing an instrumented fusion in addition to decompression may avoid revision and improve outcomes. The aim of the SpInOuT feasibility study was to establish whether a definitive randomized controlled trial (RCT) that accounted for the spectrum of pathology contributing to spinal stenosis, including pelvic incidence-lumbar lordosis (PI-LL) mismatch and mobile spondylolisthesis, could be conducted.

Aims

The aim of this study was to investigate whether the type of cervical disc herniation influences the severity of symptoms at the time of presentation, and the outcome after surgical treatment.

Aims

The aim of this study was to assess the accuracy of pedicle screw placement, as well as intraoperative factors, radiation exposure, and complication rates in adult patients with degenerative disorders of the thoracic and lumbar spines who have undergone robotic-navigated spinal surgery using a contemporary system.

Aims

Postoperative complication rates remain relatively high after adult spinal deformity (ASD) surgery. The extent to which modifiable patient-related factors influence complication rates in patients with ASD has not been effectively evaluated. The aim of this retrospective cohort study was to evaluate the association between modifiable patient-related factors and complications after corrective surgery for ASD.

Aims

CRP is an acute-phase protein that is used as a biomarker to follow severity and progression in infectious and inflammatory diseases. Its pathophysiological mechanisms of action are still poorly defined. CRP in its pentameric form exhibits weak anti-inflammatory activity. The monomeric isoform (mCRP) exerts potent proinflammatory properties in chondrocytes, endothelial cells, and leucocytes. No data exist regarding mCRP effects in human intervertebral disc (IVD) cells. This work aimed to verify the pathophysiological relevance of mCRP in the aetiology and/or progression of IVD degeneration.

Aims

Vertebral body tethering (VBT) is a non-fusion technique to correct scoliosis. It allows correction of scoliosis through growth modulation (GM) by tethering the convex side to allow concave unrestricted growth similar to the hemiepiphysiodesis concept. The other modality is anterior scoliosis correction (ASC) where the tether is able to perform most of the correction immediately where limited growth is expected.

Aims

Although lumbosacral transitional vertebrae (LSTV) are well-documented, few large-scale studies have investigated thoracolumbar transitional vertebrae (TLTV) and spinal numerical variants. This study sought to establish the prevalence of numerical variants and to evaluate their relationship with clinical problems.

Aims

To determine the effectiveness of prone traction radiographs in predicting postoperative slip distance, slip angle, changes in disc height, and lordosis after surgery for degenerative spondylolisthesis of the lumbar spine.

Aims

To study the associations of lumbar developmental spinal stenosis (DSS) with low back pain (LBP), radicular leg pain, and disability.

Aims

Intraoperative 3D navigation (ION) allows high accuracy to be achieved in spinal surgery, but poor workflow has prevented its widespread uptake. The technical demands on ION when used in patients with adolescent idiopathic scoliosis (AIS) are higher than for other more established indications. Lean principles have been applied to industry and to health care with good effects. While ensuring optimal accuracy of instrumentation and safety, the implementation of ION and its associated productivity was evaluated in this study for AIS surgery in order to enhance the workflow of this technique. The aim was to optimize the use of ION by the application of lean principles in AIS surgery.

With the identification of literature shortfalls on the techniques employed in intraoperative navigated (ION) spinal surgery, we outline a number of measures which have been synthesised into a coherent operative technique. These include positioning, dissection, management of the reference frame, the grip, the angle of attack, the drill, the template, the pedicle screw, the wire, and navigated intrathecal analgesia. Optimizing techniques to improve accuracy allow an overall reduction of the repetition of the surgical steps with its associated productivity benefits including time, cost, radiation, and safety.

Cite this article: Bone Joint J 2020;102-B(3):371–375.

Aims

It is uncertain whether instrumented spinal fixation in nonambulatory children with neuromuscular scoliosis should finish at L5 or be extended to the pelvis. Pelvic fixation has been shown to be associated with up to 30% complication rates, but is regarded by some as the standard for correction of deformity in these conditions. The incidence of failure when comparing the most caudal level of instrumentation, either L5 or the pelvis, using all-pedicle screw instrumentation has not previously been reported. In this retrospective study, we compared nonambulatory patients undergoing surgery at two centres: one that routinely instrumented to L5 and the other to the pelvis.

Aims

The aim of this study was to compare the peak pull-out force (PPF) of pedicle-lengthening screws (PLS) and traditional pedicle screws (TPS) using instant and cyclic fatigue testing.

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.

Objectives

The objective of this study was to assess the association between whole body sagittal balance and risk of falls in elderly patients who have sought treatment for back pain. Balanced spinal sagittal alignment is known to be important for the prevention of falls. However, spinal sagittal imbalance can be markedly compensated by the lower extremities, and whole body sagittal balance including the lower extremities should be assessed to evaluate actual imbalances related to falls.

Aims

In this prospective observational study, we investigated the time-dependent changes and correlations of upper arm performance tests (ten-second test and Simple Test for Evaluating Hand Function (STEF), the Japanese Orthopaedic Association (JOA) score, and the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) in 31 patients with cervical myelopathy who had undergone surgery.

Methods

In this study of patients who underwent internal fixation without fusion for a burst thoracolumbar or lumbar fracture, we compared the serial changes in the injured disc height (DH), and the fractured vertebral body height (VBH) and kyphotic angle between patients in whom the implants were removed and those in whom they were not. Radiological parameters such as injured DH, fractured VBH and kyphotic angle were measured. Functional outcomes were evaluated using the Greenough low back outcome scale and a VAS scale for pain.

Objectives

To employ a simple and fast method to evaluate those patients with neurological deficits and misplaced screws in relatively safe lumbosacral spine, and to determine if it is necessary to undertake revision surgery.

Aims

A total of 30 patients with thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) treated between 1989 and 2000 with anterior correction and fusion surgery using dual-rod instrumentation were reviewed.

Aims

Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed non-operatively or operatively in our institution.

The identification of the extent of neural damage in patients with acute or chronic spinal cord injury is imperative for the accurate prediction of neurological recovery. The changes in signal intensity shown on routine MRI sequences are of limited value for predicting functional outcome. Diffusion tensor imaging (DTI) is a novel radiological imaging technique which has the potential to identify intact nerve fibre tracts, and has been used to image the brain for a variety of conditions. DTI imaging of the spinal cord is currently only a research tool, but preliminary studies have shown that it holds considerable promise in predicting the severity of spinal cord injury.

This paper briefly reviews our current knowledge of this technique.

Clinical, radiological, and Scoliosis Research Society-22 questionnaire data were reviewed pre-operatively and two years post-operatively for patients with thoracolumbar/lumbar adolescent idiopathic scoliosis treated by posterior spinal fusion using a unilateral convex segmental pedicle screw technique. A total of 72 patients were included (67 female, 5 male; mean age at surgery 16.7 years (13 to 23)) and divided into groups: group 1 included 53 patients who underwent fusion between the vertebrae at the limit of the curve (proximal and distal end vertebrae); group 2 included 19 patients who underwent extension of the fusion distally beyond the caudal end vertebra.

A mean scoliosis correction of 80% (45% to 100%) was achieved. The mean post-operative lowest instrumented vertebra angle, apical vertebra translation and trunk shift were less than in previous studies. A total of five pre-operative radiological parameters differed significantly between the groups and correlated with the extension of the fusion distally: the size of the thoracolumbar/lumbar curve, the lowest instrumented vertebra angle, apical vertebra translation, the Cobb angle on lumbar convex bending and the size of the compensatory thoracic curve. Regression analysis allowed an equation incorporating these parameters to be developed which had a positive predictive value of 81% in determining whether the lowest instrumented vertebra should be at the caudal end vertebra or one or two levels more distal. There were no differences in the Scoliosis Research Society-22 outcome scores between the two groups (p = 0.17).

In conclusion, thoracolumbar/lumbar curves in patients with adolescent idiopathic scoliosis may be effectively treated by posterior spinal fusion using a unilateral segmental pedicle screw technique. Five radiological parameters correlate with the need for distal extension of the fusion, and an equation incorporating these parameters reliably informs selection of the lowest instrumented vertebra.

Cite this article: Bone Joint J 2014;96-B:1082–9.

Objectives

To evaluate the neck strength of school-aged rugby players, and to define the relationship with proxy physical measures with a view to predicting neck strength.

A combined anterior and posterior surgical approach is generally recommended in the treatment of severe congenital kyphosis, despite the fact that the anterior vascular supply of the spine and viscera are at risk during exposure. The aim of this study was to determine whether the surgical treatment of severe congenital thoracolumbar kyphosis through a single posterior approach is feasible, safe and effective.

We reviewed the records of ten patients with a mean age of 11.1 years (5.4 to 14.1) who underwent surgery either by pedicle subtraction osteotomy or by vertebral column resection with instrumented fusion through a single posterior approach.

The mean kyphotic deformity improved from 59.9° (45° to 110°) pre-operatively to 17.5° (3° to 40°) at a mean follow-up of 47.0 months (29 to 85). Spinal cord monitoring was used in all patients and there were no complications during surgery. These promising results indicate the possible advantages of the described technique over the established procedures. We believe that surgery should be performed in case of documented progression and before structural secondary curves develop. Our current strategy after documented progression is to recommend surgery at the age of five years and when 90% of the diameter of the spinal canal has already developed.

Cite this article: Bone Joint J 2013;95-B:1527–32.

The purpose of this study was to determine whether patients with a burst fracture of the thoracolumbar spine treated by short segment pedicle screw fixation fared better clinically and radiologically if the affected segment was fused at the same time. A total of 50 patients were enrolled in a prospective study and assigned to one of two groups. After the exclusion of three patients, there were 23 patients in the fusion group and 24 in the non-fusion group. Follow-up was at a mean of 23.9 months (18 to 30). Functional outcome was evaluated using the Greenough Low Back Outcome Score. Neurological function was graded using the American Spinal Injury Association Impairment Scale. Radiological outcome was assessed on the basis of the angle of kyphosis.

Peri-operative blood transfusion requirements and duration of surgery were significantly higher in the fusion group (p = 0.029 and p < 0.001, respectively). There were no clinical or radiological differences in outcome between the groups (all outcomes p > 0.05). The results of this study suggest that adjunctive fusion is unnecessary when managing patients with a burst fracture of the thoracolumbar spine with short segment pedicle screw fixation.

Traumatic atlanto-occipital dislocation in adults is usually fatal and survival without neurological deficit is rare. The surgical management of those who do survive is difficult and controversial. Most authorities recommend posterior occipitoaxial fusion, but this compromises cervical rotation. We describe a case in which a patient with a traumatic atlanto-occipital disruption but no neurological deficit was treated by atlanto-occipital fusion using a new technique consisting of cancellous bone autografting supported by an occipital plate linked by rods to lateral mass screws in the atlas. The technique is described in detail. At one year the neck was stable, radiological fusion had been achieved, and atlantoaxial rotation preserved.

The rationale behind this approach is discussed and the relevant literature reviewed. We recommend the technique for injuries of this type.

We reviewed the outcome of a retrospective case series of eight patients with atlantoaxial instability who had been treated by percutaneous anterior transarticular screw fixation and grafting under image-intensifier guidance between December 2005 and June 2008.

The mean follow-up was 19 months (8 to 27). All eight patients had a solid C1–2 fusion. There were no breakages or displacement of screws. All the patients with pre-operative neck pain had immediate relief from their symptoms or considerable improvement. There were no major complications. Our preliminary clinical results suggest that percutaneous anterior transarticulation screw fixation is technically feasible, safe, useful and minimally invasive when using the appropriate instruments allied to intra-operative image intensification, and by selecting the correct puncture point, angle and depth of insertion.

There are few reports on the treatment of pyogenic lumbar spondylodiscitis through the posterior approach using a single incision. Between October 1999 and March 2003 we operated on 18 patients with pyogenic lumbar spondylodiscitis. All underwent posterior lumbar interbody fusion using an autogenous bone graft from the iliac crest and pedicle screws via a posterior approach. The clinical outcome was assessed using the Frankel neurological classification and the criteria of Kirkaldy-Willis. Under the Frankel classification, two patients improved by two grades (C to E), 11 by one grade, and five showed no change. The Kirkaldy-Willis functional outcome was excellent in five patients, good in ten and fair in three. Bony union was confirmed six months after surgery in 17 patients, but in one patient this was not achieved until two years after operation. The mean lordotic angle before operation was 20° (−2° to 42°) and the mean lordotic angle at the final follow-up was 32.5° (17° to 44°). Two patients had a superficial wound infection and two a transient root injury. Posterior lumbar interbody fusion with an autogenous iliac crest bone graft and pedicle screw fixation via a posterior approach can provide satisfactory results in pyogenic spondylodiscitis.

We describe a modified technique of micro-decompression of the lumbar spine involving the use of an operating microscope, a malleable retractor and a high-speed burr, which allows decompression to be performed on both sides of the spine through a unilateral, hemi-laminectomy approach. The first 100 patients to be treated with this technique have been evaluated prospectively using a visual analogue score for sciatica and back pain, the MacNab criteria for patient satisfaction, and functional assessment with the Oswestry Disability Index.

After a period of follow-up from 12 months to six years and four months, sciatica had improved in 90 patients and back pain in 84 patients. Their result was graded as good or excellent by 82 patients according to the MacNab criteria, and 75 patients had subjective improvement in their walking distance. Late instability developed in four patients.

Lumbar micro-decompression has proved to be safe, with few complications. Postoperative instability requiring fusion was uncommon, and less than using traditional approaches in published series.

We evaluated 30 patients with cervical myelopathy before and after decompressive surgery and compared them with 42 healthy controls. All were asked to grip and release their fingers as rapidly as possible for 15 seconds. Films recorded with a digital camera were divided into three files of five seconds each. Three doctors independently counted the number of grip and release cycles in a blinded manner (N1 represents the number of cycles for the first five-second segment, N2 for the second and N3 for the third). N2 and N3 of the pre-operative group were significantly fewer than those of the control group, and the postoperative group’s results were significantly greater than those of the pre-operative group. In the control group, the numbers decreased significantly with each succeeding five-second interval (fatigue phenomenon). In the pre-operative myelopathy group there was no significant difference between N1 and N2 (freezing phenomenon).

The 15-second test is shown to be reliable in the quantitative evaluation of cervical myelopathy. Although it requires a camera and animation files, it can detect small changes in neurological status because of its precise and objective nature.

We have analysed a number of radiological measurements in an attempt to clarify the predisposing factors for degenerative spondylolisthesis of the lumbosacral junction. We identified 57 patients with a slip and a control group of 293 patients without any radiological abnormality apart from age-related changes. The relative thickness of the L5 transverse process, the sacral table angle and the height of the iliac crest were measured and evaluated. The difference in these measurements between men and women was analysed in the control group.

We found that the transverse process of L5 was extremely slender, the sacral table more inclined, and the L5 vertebra was less deeply placed in the pelvis in patients with a slip compared with the control group. The differences in these three parameters were statistically significant.

We believe that the L5 vertebra is predisposed to slip when these factors act together on a rigidly-stabilised sacrum. This occurs more commonly in women, probably as a result of constitutional differences in the development of the male and female spine.

Bertolotti’s syndrome is characterised by anomalous enlargement of the transverse process(es) of the most caudal lumbar vertebra which may articulate or fuse with the sacrum or ilium and cause isolated L4/5 disc disease.

We analysed the elective MR scans of the lumbosacral spine of 769 consecutive patients with low back pain taken between July 2003 and November 2004. Of these 568 showed disc degeneration. Bertolotti’s syndrome was present in 35 patients with a mean age of 32.7 years (15 to 60). This was a younger age than that of patients with multiple disc degeneration, single-level disease and isolated disc degeneration at the L4/5 level (p ≤ 0.05). The overall incidence of Bertolotti’s syndrome in our study was 4.6% (35 of 769). It was present in 11.4% (20 patients) of the under-30 age group.

Our findings suggest that Bertolotti’s syndrome must form part of a list of differential diagnoses in the investigation of low back pain in young people.

Between January 1990 and December 2000 we carried out 226 SB Charité III disc replacements for lumbar disc degeneration in 160 patients. They were reviewed at a mean follow-up of 79 months (31 to 161) to determine the clinical and radiological outcome. The clinical results were collected by an independent observer, who was not involved in patient selection, treatment or follow-up, using a combination of outcome measures, including the Oswestry Disability Index. Pain was recorded using a visual analogue score, and the most recent radiographs were reviewed.

Survival of the device was analysed by the Kaplan-Meier method and showed a cumulative survival of 35% at 156 months when radiological failure was taken as the endpoint. The mean improvement in the Oswestry disability index scores after disc replacement was 14% (6% to 21%) and the mean improvement in the pain score was 1.6 (0.46 to 2.73), both falling below the clinically significant threshold. Removal of the implant was required in 12 patients, four because of implant failure.

These poor results indicate that further use of this implant is not justified.

Low back injuries account for the greatest loss of playing time for professional fast bowlers in cricket. Previous radiological studies have shown a high prevalence of degeneration of the lumbar discs and stress injuries of the pars interarticularis in elite junior fast bowlers. We have examined MRI appearance of the lumbar spines of 36 asymptomatic professional fast bowlers and 17 active control subjects. The fast bowlers had a relatively high prevalence of multi-level degeneration of the lumbar discs and a unique pattern of stress lesions of the pars interarticularis on the non-dominant side. The systems which have been used to classify the MR appearance of the lumbar discs and pars were found to be reliable. However, the relationship between the radiological findings, pain and dysfunction remains unclear.

We present data relating to the Bryan disc arthroplasty for the treatment of cervical spondylosis in 46 patients.

Patients with either radiculopathy or myelopathy had a cervical discectomy followed by implantation of a cervical disc prosthesis. Patients were reviewed at six weeks, six months and one year and assessment included three outcome measures, a visual analogue scale (VAS), the short form 36 (SF-36) and the neck disability index (NDI). The results were categorised according to a modification of Odom’s criteria. Radiological evaluation, by an independent radiologist, sought evidence of movement, stability and subsidence of the prosthesis.

A highly significant difference was found for all three outcome measurements, comparing the pre-operative with the post-operative values: VAS (Z = 6.42, p < 0.0001), SF-36 (mental component) (Z = −5.02, p < 0.0001), SF-36 (physical component) (Z = −5.00, p < 0.0001) and NDI (Z = 7.03, p < 0.0001). The Bryan cervical disc prosthesis seems reliable and safe in the treatment of patients with cervical spondylosis.