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. A total of 60 lumbar vertebrae were divided into six groups:
PLS submitted to instant pull-out and fatigue-resistance testing
(groups A1 and A2, respectively), TPS submitted to instant pull-out
and fatigue-resistance testing (groups B1 and B2, respectively)
and PLS augmented with 2 ml polymethylmethacrylate, submitted to
instant pull-out and fatigue-resistance testing (groups C1 and C2,
respectively). The PPF and normalized PPF (PPFn) for bone mineral density
(BMD) were compared within and between all groups.Aims
Materials and Methods
Objectives. Loss of motion following spine segment fusion results in increased strain in the adjacent motion segments. However, to date, studies on the
To determine the major risk factors for unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) and their interactions, using machine learning-based prediction algorithms and game theory. Patients who underwent surgery for ASD, with a minimum of two-year follow-up, were retrospectively reviewed. In total, 210 patients were included and randomly allocated into training (70% of the sample size) and test (the remaining 30%) sets to develop the machine learning algorithm. Risk factors were included in the analysis, along with clinical characteristics and parameters acquired through diagnostic radiology.Aims
Methods
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. As part of the SpInOuT-F study, a pilot randomized trial was carried out across five NHS hospitals. Patients were randomized to either spinal decompression alone or spinal decompression plus instrumented fusion. Patient-reported outcome measures were collected at baseline and three months. The intended sample size was 60 patients.Aims
Methods
To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing. Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included “brace treatment” or “bracing,” “idiopathic scoliosis,” and “curve regression” or “curve reduction.” Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication.Aims
Methods
The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique. This was a multicentre retrospective study involving consecutively enrolled patients who underwent L4-L5 LLIF by seven surgeons at seven institutions in three countries over a five-year period. The demographic details of the patients and the details of the surgery, reoperations and complications, including femoral and non-femoral neuropraxia, thigh pain, weakness of hip flexion, and abdominal complications, were analyzed. Neurological and psoas-related complications attributed to LLIF or posterior instrumentation and persistent symptoms were recorded at one year postoperatively.Aims
Methods
The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment. Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery.Aims
Methods
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. We conducted a retrospective analysis of clinical and radiological data of 20 patients aged between 9 and 17 years old, (with a 19 female: 1 male ratio) between January 2014 to December 2016 with a mean five-year follow-up (4 to 7).Aims
Methods
Anchorage of pedicle screw rod instrumentation in the elderly spine with poor bone quality remains challenging. Our study aims to evaluate how the screw bone anchorage is affected by screw design, bone quality, loading conditions, and cementing techniques. Micro-finite element (µFE) models were created from micro-CT (μCT) scans of vertebrae implanted with two types of pedicle screws (L: Ennovate and R: S4). Simulations were conducted for a 10 mm radius region of interest (ROI) around each screw and for a full vertebra (FV) where different cementing scenarios were simulated around the screw tips. Stiffness was calculated in pull-out and anterior bending loads.Aims
Methods
Lumbar spondylolysis is a stress fracture of the pars interarticularis. We have evaluated the site of origin of the fracture clinically and
Objectives. Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this
Aims. Loosening of pedicle screws is a major complication of posterior
spinal stabilisation, especially in the osteoporotic spine. Our
aim was to evaluate the effect of cement augmentation compared with
extended dorsal instrumentation on the stability of posterior spinal
fixation. Materials and Methods. A total of 12 osteoporotic human cadaveric spines (T11-L3) were
randomised by bone mineral density into two groups and instrumented
with pedicle screws: group I (SHORT) separated T12 or L2 and group
II (EXTENDED) specimen consisting of T11/12 to L2/3. Screws were
augmented with cement unilaterally in each vertebra. Fatigue testing
was performed using a cranial-caudal sinusoidal, cyclic (1.0 Hz)
load with stepwise increasing peak force. Results. Augmentation showed no significant increase in the mean cycles
to failure and fatigue force (SHORT p = 0.067; EXTENDED p = 0.239).
Extending the instrumentation resulted in a significantly increased
number of cycles to failure and a significantly higher fatigue force
compared with the SHORT instrumentation (EXTENDED non-augmented
+ 76%, p <
0.001; EXTENDED augmented + 87%, p <
0.001). Conclusion. The stabilising effect of cement augmentation of pedicle screws
might not be as beneficial as expected from
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. A total of 1,179 patients who had undergone thoracic, abdominal, and pelvic CT scanning were divided into groups according to the number of thoracic and lumbar vertebrae, and the presence or absence of TLTV or LSTV. The prevalence of spinal anomalies was noted. The relationship of spinal anomalies to clinical symptoms (low back pain, Japanese Orthopaedic Association score, Roland-Morris Disability Questionnaire) and degenerative spondylolisthesis (DS) was also investigated.Aims
Methods
To evaluate the perioperative complications associated with total en bloc spondylectomy (TES) in patients with spinal tumours, based on the extent and level of tumour resection. In total, 307 patients who underwent TES in a single centre were reviewed retrospectively. There were 164 male and 143 female patients with a mean age at the time of surgery of 52.9 years (SD 13.3). A total of 225 patients were operated on for spinal metastases, 34 for a malignant primary tumour, 41 for an aggressive benign tumour, and seven with a primary of unknown origin. The main lesion was located in the thoracic spine in 213, and in the lumbar spine in 94 patients. There were 97 patients who underwent TES for more than two consecutive vertebrae.Aims
Methods
The aim of this study was to determine the differences in spinal imaging characteristics between subjects with or without lumbar developmental spinal stenosis (DSS) in a population-based cohort. This was a radiological analysis of 2,387 participants who underwent L1-S1 MRI. Means and ranges were calculated for age, sex, BMI, and MRI measurements. Anteroposterior (AP) vertebral canal diameters were used to differentiate those with DSS from controls. Other imaging parameters included vertebral body dimensions, spinal canal dimensions, disc degeneration scores, and facet joint orientation. Mann-Whitney U and chi-squared tests were conducted to search for measurement differences between those with DSS and controls. In order to identify possible associations between DSS and MRI parameters, those who were statistically significant in the univariate binary logistic regression were included in a multivariate stepwise logistic regression after adjusting for demographics. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported where appropriate.Aims
Methods
We examined the reliability of radiological findings in predicting segmental instability in 112 patients (56 men, 56 women) with a mean age of 66.5 years (27 to 84) who had degenerative disease of the lumbar spine. They underwent intra-operative
Whether a combined anteroposterior fusion or a posterior-only fusion is more effective in the management of patients with Scheuermann’s kyphosis remains controversial. The aim of this study was to compare the radiological and clinical outcomes of these surgical approaches, and to evaluate the postoperative complications with the hypothesis that proximal junctional kyphosis would be more common in one-stage posterior-only fusion. A retrospective review of patients treated surgically for Scheuermann’s kyphosis between 2006 and 2014 was performed. A total of 62 patients were identified, with 31 in each group. Parameters were compared to evaluate postoperative outcomes using chi-squared tests, independent-samples Aims
Methods
The current pandemic caused by COVID-19 is the biggest challenge for national health systems for a century. While most medical resources are allocated to treat COVID-19 patients, several non-COVID-19 medical emergencies still need to be treated, including vertebral fractures and spinal cord compression. The aim of this paper is to report the early experience and an organizational protocol for emergency spinal surgery currently being used in a large metropolitan area by an integrated team of orthopaedic surgeons and neurosurgeons. An organizational model is presented based on case centralization in hub hospitals and early management of surgical cases to reduce hospital stay. Data from all the patients admitted for emergency spinal surgery from the beginning of the outbreak were prospectively collected and compared to data from patients admitted for the same reason in the same time span in the previous year, and treated by the same integrated team.Aims
Methods
Inflammatory response plays a pivotal role in the pathophysiological process of intervertebral disc degeneration (IDD). A20 (also known as tumour necrosis factor alpha-induced protein 3 (TNFAIP3)) is a ubiquitin-editing enzyme that restricts nuclear factor-kappa B (NF-κB) signalling. A20 prevents the occurrence of multiple inflammatory diseases. However, the role of A20 in the initiation of IDD has not been elucidated. The aim of the study was to investigate the effect of A20 in senescence of TNF alpha (TNF-α)-induced nucleus pulposus cells (NPCs). Immunohistochemical staining was performed to observe the expression of A20 in normal and degenerated human intervertebral discs. The NPCs were dissected from the tail vertebrae of healthy male Sprague-Dawley rats and were cultured in the incubator. In the experiment, TNF-α was used to mimic the inflammatory environment of IDD. The cell viability and senescence were examined to investigate the effect of A20 on TNF-α-treated NPCs. The expression of messenger RNA (mRNA)-encoding proteins related to matrix macromolecules (collagen II, aggrecan) and senescence markers (p53, p16). Additionally, NF-κB/p65 activity of NPCs was detected within different test compounds.Aims
Methods
Chronic low back pain due to degenerative disc disease is sometimes treated with fusion. We compared the outcome of three different fusion techniques in the Swedish Spine Register: noninstrumented posterolateral fusion (PLF), instrumented posterolateral fusion (IPLF), and interbody fusion (IBF). A total of 2874 patients who were operated on at one or two lumbar levels were followed for a mean of 9.2 years (3.6 to 19.1) for any additional lumbar spine surgery. Patient-reported outcome data were available preoperatively (n = 2874) and at one year (n = 2274), two years (n = 1958), and a mean of 6.9 years (n = 1518) postoperatively and consisted of global assessment and visual analogue scales of leg and back pain, Oswestry Disability Index, EuroQol five-dimensional index, 36-Item Short-Form Health Survey, and satisfaction with treatment. Statistical analyses were performed with competing-risks proportional hazards regression or analysis of covariance, adjusted for baseline variables.Aims
Patients and Methods
Idiopathic scoliosis is the most common spinal deformity in adolescents and children. The aetiology of the disease remains unknown. Previous studies have shown a lower bone mineral density in individuals with idiopathic scoliosis, which may contribute to the causation. The aim of the present study was to compare bone health in adolescents with idiopathic scoliosis with controls. We included 78 adolescents with idiopathic scoliosis (57 female patients) at a mean age of 13.7 years (8.5 to 19.6) and 52 age- and sex-matched healthy controls (39 female patients) at a mean age of 13.8 years (9.1 to 17.6). Mean skeletal age, estimated according to the Tanner-Whitehouse 3 system (TW3), was 13.4 years (7.4 to 17.8) for those with idiopathic scoliosis, and 13.1 years (7.4 to 16.5) for the controls. Mean Cobb angle for those with idiopathic scoliosis was 29° (SD 11°). All individuals were scanned with dual energy x-ray absorptiometry (DXA) and peripheral quantitative CT (pQCT) of the left radius and tibia to assess bone density. Statistical analyses were performed with independent-samples Aims
Methods
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. A total of 20 consecutive patients with AIS were treated with ION corrective spinal surgery. Both qualitative and quantitative analysis was performed with real-time modifications. Operating time, scan time, dose length product (measure of CT radiation exposure), use of fluoroscopy, the influence of the reference frame, blood loss, and neuromonitoring were assessed.Aims
Methods
This prospective multicentre study was undertaken
to determine segmental movement, disc height and sagittal alignment
after total disc replacement (TDR) in the lumbosacral spine and
to assess the correlation of
The aim of this study was to explore risk factors for complications associated with dural tear (DT), including the types of DT, and the intra- and postoperative management of DT. Between 2012 and 2017, 12 171 patients with degenerative lumbar diseases underwent primary lumbar spine surgery. We investigated five categories of potential predictors: patient factors (sex, age, body mass index, and primary disease), surgical factors (surgical procedures, operative time, and estimated blood loss), types of DT (inaccessible for suturing/clipping and the presence of cauda equina/nerve root herniation), repair techniques (suturing, clipping, fibrin glue, polyethylene glycol (PEG) hydrogel, and polyglycolic acid sheet), and postoperative management (drainage duration). Postoperative complications were evaluated in terms of dural leak, prolonged bed rest, headache, nausea/vomiting, delayed wound healing, postoperative neurological deficit, surgical site infection (SSI), and reoperation for DT. We performed multivariable regression analyses to evaluate the predictors of postoperative complications associated with DT.Aims
Patients and Methods
A vascularised fibular strut graft was used for anterior spinal fusion in 16 patients with spinal kyphosis. The procedure was abandoned in three because of difficulty in establishing a vascular anastomosis and in one because the grafted fibula dislodged two days after operation. One patient died after five days. Of the 11 remaining patients, there were seven males and four females. Their ages at the time of operation averaged 30.9 years (12 to 71). The number of vertebrae fused averaged 6.7 (5 to 9) and the length of fibula grafted averaged 10.9 cm (6.5 to 18). Average follow-up was 54 months (27 to 84). Bone union occurred at both ends of the grafted fibula in all 11 patients, with an average time to union of 5.5 months (3 to 8). We did not see a fracture of the grafted fibula. Two patients had postoperative complications; the graft dislodged in one and laryngeal oedema occurred two days after operation in the other. A vascularised fibular strut graft provides a
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. 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.Objectives
Methods
We aimed to retrospectively assess the accuracy and safety of
CT navigated pedicle screws and to compare accuracy in the cervical
and thoracic spine (C2-T8) with (COMB) and without (POST) prior
anterior surgery (anterior cervical discectomy or corpectomy and
fusion with ventral plating: ACDF/ACCF). A total of 592 pedicle screws, which were used in 107 consecutively
operated patients (210 COMB, 382 POST), were analysed. The accuracy
of positioning was determined according to the classification of
Gertzbein and Robbins on post-operative CT scans.Aims
Patients and Methods
We present the results of correcting a double or triple curve
adolescent idiopathic scoliosis using a convex segmental pedicle
screw technique. We reviewed 191 patients with a mean age at surgery of 15 years
(11 to 23.3). Pedicle screws were placed at the convexity of each
curve. Concave screws were inserted at one or two cephalad levels
and two caudal levels. The mean operating time was 183 minutes (132
to 276) and the mean blood loss 0.22% of the total blood volume
(0.08% to 0.4%). Multimodal monitoring remained stable throughout
the operation. The mean hospital stay was 6.8 days (5 to 15).Aims
Patients and Methods
In order to evaluate the effectiveness of the Mobi-C implant
in cervical disc degeneration, a randomised study was conducted,
comparing the Mobi-C prosthesis arthroplasty with anterior cervical
disc fusion (ACDF) in patients with single level cervical spondylosis. From January 2008 to July 2009, 99 patients were enrolled and
randomly divided into two groups, those having a Mobi-C implant
(n = 51; 30 men, 21 women) and those undergoing ACDF (n = 48; 28
men, 20 women).The patients were followed up for five years, with
the primary outcomes being the Japanese Orthopaedic Association
score, visual analogue scale for pain and the incidence of further
surgery. The secondary outcomes were the Neck Disability Index and
range of movement (ROM) of the treated segment.Aims
Patients and Methods
Many aspects of the surgical treatment of patients with tuberculosis
(TB) of the spine, including the use of instrumentation and the
types of graft, remain controversial. Our aim was to report the
outcome of a single-stage posterior procedure, with or without posterior
decompression, in this group of patients. Between 2001 and 2010, 51 patients with a mean age of 62.5 years
(39 to 86) underwent long posterior instrumentation and short posterior
or posterolateral fusion for TB of the thoracic and lumbar spines,
followed by anti-TB chemotherapy for 12 months. No anterior debridement
of the necrotic tissue was undertaken. Posterior decompression with
laminectomy was carried out for the 30 patients with a neurological
deficit.Aim
Patients and Methods
The aims of our study were to provide long-term information on
the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic
anterior correction and fusion (ASF) and to determine the impact
of ASF on pulmonary function. A total of 41 patients (four males, 37 females) with main thoracic
(MT) adolescent idiopathic scoliosis (AIS) treated with ASF were
included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up
period was 13.5 years (10 to 18).Aims
Patients and Methods
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. Radiographic parameters and clinical outcomes were compared among
patients with lowest instrumented vertebra (LIV) at the lower end
vertebra (LEV; EV group) (n = 13) and those treated by short fusion
(S group), with LIV one level proximal to EV (n = 17 patients). Aims
Patients and Methods
The aims of this study were to evaluate the clinical and radiological
outcomes of instrumented posterolateral fusion (PLF) performed in
patients with rheumatoid arthritis (RA). A total of 40 patients with RA and 134 patients without RA underwent
instrumented PLF for spinal stenosis between January 2003 and December
2011. The two groups were matched for age, gender, bone mineral
density, the history of smoking and diabetes, and number of fusion
segments. The clinical outcomes measures included the visual analogue scale
(VAS) and the Korean Oswestry Disability Index (KODI), scored before
surgery, one year and two years after surgery. Radiological outcomes
were evaluated for problems of fixation, nonunion, and adjacent
segment disease (ASD). The mean follow-up was 36.4 months in the RA
group and 39.1 months in the non-RA group.Aims
Methods
Percutaneous placement of pedicle screws is a
well-established technique, however, no studies have compared percutaneous
and open placement of screws in the thoracic spine. The aim of this
cadaveric study was to compare the accuracy and safety of these
techniques at the thoracic spinal level. A total of 288 screws were
inserted in 16 (eight cadavers, 144 screws in percutaneous and eight
cadavers, 144 screws in open). Pedicle perforations and fractures
were documented subsequent to wide laminectomy followed by skeletalisation
of the vertebrae. The perforations were classified as grade 0: no
perforation, grade 1: <
2 mm perforation, grade 2: 2 mm to 4
mm perforation and grade 3: >
4 mm perforation. In the percutaneous
group, the perforation rate was 11.1% with 15 (10.4%) grade 1 and
one (0.7%) grade 2 perforations. In the open group, the perforation
rate was 8.3% (12 screws) and all were grade 1. This difference
was not significant (p = 0.45). There were 19 (13.2%) pedicle fractures
in the percutaneous group and 21 (14.6%) in the open group (p =
0.73). In summary, the safety of percutaneous fluoroscopy-guided
pedicle screw placement in the thoracic spine between T4 and T12
is similar to that of the conventional open technique. Cite this article:
Cardiac disease in patients with ankylosing spondylitis
(AS) has previously been studied but not in patients with a kyphosis
or in those who have undergone an operation to correct it. The aim of this study was to measure the post-operative changes
in cardiac function of patients with an AS kyphosis after pedicle
subtraction osteotomy (PSO). The original cohort consisted of 39 patients (33 men, six women).
Of these, four patients (two men, two women) were lost to follow-up
leaving 35 patients (31 men, four women) to study. The mean age
of the remaining patients was 37.4 years (22.3 to 47.8) and their
mean duration of AS was 17.0 years (4.6 to 26.4). Echocardiographic measurements,
resting heart rate (RHR), physical function score (PFS), and full-length
standing spinal radiographs were obtained before surgery and at
the two-year follow-up. The mean pre-operative RHR was 80.2 bpm (60.6 to 112.3) which
dropped to a mean of 73.7 bpm (60.7 to 90.6) at the two-year follow-up
(p = 0.0000). Of 15 patients with normal ventricular function pre-operatively,
two developed mild left ventricular diastolic dysfunction (LVDD)
at the two-year follow-up. Of 20 patients with mild LVDD pre-operatively
only five had this post-operatively. Overall, 15 patients had normal
LV diastolic function before their operation and 28 patients had
normal LV function at the two-year follow-up. The clinical improvement was 15 out of 20 (75.0%): cardiac function
in patients with AS whose kyphosis was treated by PSO was significantly
improved. Cite this article:
We evaluated the impact of lumbar instrumented
circumferential fusion on the development of adjacent level vertebral
compression fractures (VCFs). Instrumented posterior lumbar interbody
fusion (PLIF) has become a popular procedure for degenerative lumbar
spine disease. The immediate rigidity produced by PLIF may cause
more stress and lead to greater risk of adjacent VCFs. However,
few studies have investigated the relationship between PLIF and
the development of subsequent adjacent level VCFs. Between January 2005 and December 2009, a total of 1936 patients
were enrolled. Of these 224 patients had a new VCF and the incidence
was statistically analysed with other covariants. In total 150 (11.1%)
of 1348 patients developed new VCFs with PLIF, with 108 (72%) cases
at adjacent segment. Of 588 patients, 74 (12.5%) developed new subsequent
VCFs with conventional posterolateral fusion (PLF), with 37 (50%)
patients at an adjacent level. Short-segment fusion, female and
age older than 65 years also increased the development of new adjacent
VCFs in patients undergoing PLIF. In the osteoporotic patient, more
rigid fusion and a higher stress gradient after PLIF will cause
a higher adjacent VCF rate. Cite this article:
Mesenchymal stem-cell based therapies have been
proposed as novel treatments for intervertebral disc degeneration,
a prevalent and disabling condition associated with back pain. The
development of these treatment strategies, however, has been hindered
by the incomplete understanding of the human nucleus pulposus phenotype
and by an inaccurate interpretation and translation of animal to
human research. This review summarises recent work characterising
the nucleus pulposus phenotype in different animal models and in
humans and integrates their findings with the anatomical and physiological
differences between these species. Understanding this phenotype
is paramount to guarantee that implanted cells restore the native
functions of the intervertebral disc. Cite this article:
The purpose of this study was to determine whether
it would be feasible to use oblique lumbar interbody fixation for
patients with degenerative lumbar disease who required a fusion
but did not have a spondylolisthesis. A series of CT digital images from 60 patients with abdominal
disease were reconstructed in three dimensions (3D) using Mimics
v10.01: a digital cylinder was superimposed on the reconstructed
image to simulate the position of an interbody screw. The optimal
entry point of the screw and measurements of its trajectory were
recorded. Next, 26 cadaveric specimens were subjected to oblique
lumbar interbody fixation on the basis of the measurements derived
from the imaging studies. These were then compared with measurements
derived directly from the cadaveric vertebrae. Our study suggested that it is easy to insert the screws for
L1/2, L2/3 and L3/4 fixation: there was no significant difference
in measurements between those of the 3-D digital images and the
cadaveric specimens. For L4/5 fixation, part of L5 inferior articular
process had to be removed to achieve the optimal trajectory of the
screw. For L5/S1 fixation, the screw heads were blocked by iliac
bone: consequently, the interior oblique angle of the cadaveric specimens
was less than that seen in the 3D digital images. We suggest that CT scans should be carried out pre-operatively
if this procedure is to be adopted in clinical practice. This will
assist in determining the feasibility of the procedure and will
provide accurate information to assist introduction of the screws. Cite this article:
We investigated the spinopelvic morphology and
global sagittal balance of patients with a degenerative retrolisthesis
or anterolisthesis. A total of 269 consecutive patients with a degenerative
spondylolisthesis were included in this study. There were 95 men
and 174 women with a mean age of 64.3 years ( A backward slip was found in the upper lumbar levels (mostly
L2 or L3) with an almost equal gender distribution in both the R
and R+A groups. The pelvic incidence and sacral slope of the R group
were significantly lower than those of the A (both p <
0.001)
and R+A groups (both p <
0.001). The lumbar lordosis of the R+A
group was significantly greater than that of the R (p = 0.025) and
A groups (p = 0.014). The C7 plumb line of the R group was located
more posteriorly than that of the A group (p = 0.023), but was no
different from than that of the R+A group (p = 0.422). The location
of C7 plumb line did not differ between the three groups (p = 0.068).
The spinosacral angle of the R group was significantly smaller than
that of the A group (p <
0.001) and R+A group (p <
0.001). Our findings imply that there are two types of degenerative retrolisthesis:
one occurs primarily as a result of degeneration in patients with
low pelvic incidence, and the other occurs secondarily as a compensatory
mechanism in patients with an anterolisthesis and high pelvic incidence. Cite this article:
Whiplash injury is surrounded by controversy in both the medical and legal world. The debate on whether it is either a potentially serious medical condition or a social problem is ongoing. This paper briefly examines a selection of studies on low velocity whiplash injury (LVWI) and whiplash associated disorder (WAD) and touches upon the pathophysiological and epidemiological considerations, cultural and geographical differences and the effect of litigation on chronicity. The study concludes that the evidence for significant physical injury after LVWI is poor, and if significant disability is present after such injury, it will have to be explained in terms of psychosocial factors.
This short contribution aims to explain how intervertebral disc ‘degeneration’ differs from normal ageing, and to suggest how mechanical loading and constitutional factors interact to cause disc degeneration and prolapse. We suggest that disagreement on these matters in medico-legal practice often arises from a misunderstanding of the nature of ‘soft-tissue injuries’.
The purpose of this study was to evaluate and
compare the effect of short segment pedicle screw instrumentation and
an intermediate screw (SSPI+IS) on the radiological outcome of type
A thoracolumbar fractures, as judged by the load-sharing classification,
percentage canal area reduction and remodelling. We retrospectively evaluated 39 patients who had undergone hyperlordotic
SSPI+IS for an AO-Magerl Type-A thoracolumbar fracture. Their mean
age was 35.1 (16 to 60) and the mean follow-up was 22.9 months (12
to 36). There were 26 men and 13 women in the study group. In total,
18 patients had a load-sharing classification score of seven and
21 a score of six. All radiographs and CT scans were evaluated for
sagittal index, anterior body height compression (%ABC), spinal
canal area and encroachment. There were no significant differences
between the low and high score groups with respect to age, duration
of follow-up, pre-operative sagittal index or pre-operative anterior
body height compression (p = 0.217, 0.104, 0.104, and 0.109 respectively).
The mean pre-operative sagittal index was 19.6° (12° to 28°) which
was corrected to -1.8° (-5° to 3°) post-operatively and 2.4° (0°
to 8°) at final follow-up (p = 0.835 for sagittal deformity). No
patient needed revision for loss of correction or failure of instrumentation. Hyperlordotic reduction and short segment pedicle screw instrumentation
and an intermediate screw is a safe and effective method of treating
burst fractures of the thoracolumbar spine. It gives excellent radiological
results with a very low rate of failure regardless of whether the
fractures have a high or low load-sharing classification score. Cite this article
Transarticular screw fixation with autograft
is an established procedure for the surgical treatment of atlantoaxial instability.
Removal of the posterior arch of C1 may affect the rate of fusion.
This study assessed the rate of atlantoaxial fusion using transarticular
screws with or without removal of the posterior arch of C1. We reviewed
30 consecutive patients who underwent atlantoaxial fusion with a
minimum follow-up of two years. In 25 patients (group A) the posterior
arch of C1 was not excised (group A) and in five it was (group B).
Fusion was assessed on static and dynamic radiographs. In selected
patients CT imaging was also used to assess fusion and the position
of the screws. There were 15 men and 15 women with a mean age of
51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6).
Stable union with a solid fusion or a stable fibrous union was achieved
in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid
fusion, four (16%) a stable fibrous union and one (4%) a nonunion.
In Group B, stable union was achieved in all patients, three having
a solid fusion and two a stable fibrous union. There was no statistically
significant difference between the status of fusion in the two groups.
Complications were noted in 12 patients (40%); these were mainly
related to the screws, and included malpositioning and breakage.
The presence of an intact or removed posterior arch of C1 did not
affect the rate of fusion in patients with atlantoaxial instability
undergoing C1/C2 fusion using transarticular screws and autograft. Cite this article:
Vertebral compression fractures are the most prevalent complication of osteoporosis and percutaneous vertebroplasty (PVP) has emerged as a promising addition to the methods of treating the debilitating pain they may cause. Since PVP was first reported in the literature in 1987, more than 600 clinical papers have been published on the subject. Most report excellent improvements in pain relief and quality of life. However, these papers have been based mostly on uncontrolled cohort studies with a wide variety of inclusion and exclusion criteria. In 2009, two high-profile randomised controlled trials were published in the
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.
This article reviews the current knowledge of
the intervertebral disc (IVD) and its association with low back
pain (LBP). The normal IVD is a largely avascular and aneural structure
with a high water content, its nutrients mainly diffusing through
the end plates. IVD degeneration occurs when its cells die or become
dysfunctional, notably in an acidic environment. In the process
of degeneration, the IVD becomes dehydrated and vascularised, and
there is an ingrowth of nerves. Although not universally the case,
the altered physiology of the IVD is believed to precede or be associated
with many clinical symptoms or conditions including low back and/or
lower limb pain, paraesthesia, spinal stenosis and disc herniation. New treatment options have been developed in recent years. These
include biological therapies and novel surgical techniques (such
as total disc replacement), although many of these are still in
their experimental phase. Central to developing further methods
of treatment is the need for effective ways in which to assess patients
and measure their outcomes. However, significant difficulties remain
and it is therefore an appropriate time to be further investigating
the scientific basis of and treatment of LBP.
We reviewed 212 consecutive patients with adolescent
idiopathic scoliosis who underwent posterior spinal arthrodesis
using all pedicle screw instrumentation in terms of clinical, radiological
and Scoliosis Research Society (SRS)-22 outcomes. In Group 1 (51
patients), the correction was performed over two rods using bilateral
segmental pedicle screws. In Group 2 (161 patients), the correction
was performed over one rod using unilateral segmental pedicle screws
with the second rod providing stability of the construct
through two-level screw fixation at proximal and distal ends. The
mean age at surgery was
14.8 years in both groups. Comparison between groups showed no significant
differences with regard to age and Risser grade at surgery, pre-
and post-operative scoliosis angle, coronal Cobb correction, length
of hospital stay and SRS scores. Correction of upper thoracic curves
was significantly better in Group 1 (p = 0.02). Increased surgical time
and intra-operative blood loss was recorded in Group 1 (p <
0.001
and p = 0.04, respectively). The implant cost was reduced by mean
35% in Group 2 due to the lesser number of pedicle screws. Unilateral and bilateral pedicle screw techniques have both achieved
excellent deformity correction in adolescent patients with idiopathic
scoliosis, which was maintained at two-year follow-up. This has
been associated with high patient satisfaction and low complication
rates.
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.
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.
In patients with osteoporosis there is always
a strong possibility that pedicle screws will loosen. This makes
it difficult to select the appropriate osteoporotic patient for
a spinal fusion. The purpose of this study was to determine the
correlation between bone mineral density (BMD) and the magnitude
of torque required to insert a pedicle screw. To accomplish this,
181 patients with degenerative disease of the lumbar spine were
studied prospectively. Each underwent dual-energy x-ray absorptiometry
(DEXA) and intra-operative measurement of the torque required to
insert each pedicle screw. The levels of torque generated in patients
with osteoporosis and osteopenia were significantly lower than those
achieved in normal patients. Positive correlations were observed between
BMD and T-value at the instrumented lumbar vertebrae, mean BMD and
mean T-value of the lumbar vertebrae, and mean BMD and mean T-value
of the proximal femur. The predictive torque (Nm) generated during pedicle
screw insertion was [-0.127 + 1.62 × (BMD at the corresponding lumbar
vertebrae)], as measured by linear regression analysis. The positive
correlation between BMD and the maximum torque required to insert
a pedicle screw suggests that pre-operative assessment of BMD may
be useful in determining the ultimate strength of fixation of a
device, as well as the number of levels that need to be fixed with
pedicle screws in patients who are suspected of having osteoporosis.