1. Compression forces are mainly absorbed by the vertebral body. The nucleus pulposus, being liquid, is incompressible. The tense annulus bulges very little. On compression the vertebral end-plate bulges and blood is forced out of the cancellous bone of the vertebral body into the perivertebral sinuses. This appears to be the normal energy-dissipating mechanism on compression. 2. The normal disc is very resistant to compression. The nucleus pulposus does not alter in shape or position on compression or flexion. It plays no active part in producing a disc prolapse. On compression the vertebral body always breaks before the normal disc gives way. The vertebral end-plate bulges and then breaks, leading to a vertical fracture. If the nucleus pulposus has lost its turgor there is abnormal mobility between the vertebral bodies. On very gentle compression or flexion movement the annulus protrudes on the concave aspect–not on the convex side as has been supposed. 3. Disc prolapse consists primarily of annulus; it occurs only if the nucleus pulposus has lost its turgor. It then occurs very easily as the annulus now bulges like a flat tyre. 4. I have never succeeded in producing rupture of normal spinal ligaments by hyperextension or hyperflexion. Before rupture occurs the bone sustains a compression fracture. On the other hand horizontal shear, and particularly rotation forces, can easily cause ligamentous rupture and dislocation. 5. A combination of rotation and compression can produce almost every variety of spinal injury. In the cervical region subluxation with spontaneous reduction can be easily produced by rotation. If disc turgor is impaired this may occur with an intact anterior longitudinal ligament and explains those cases of tetraplegia without radiological changes or a torn anterior longitudinal ligament. The anterior longitudinal ligament can easily be ruptured by a rotation force and in my experience the so-called hyperextension and hyperflexion injuries are really rotation injuries. 6. Hyperflexion of the cervical spine or upper
There is little information about the optimum number of implants
to be used in the surgical treatment of idiopathic scoliosis. Retrospective
analysis of prospectively collected data from the Swedish spine
register was undertaken to discover whether more implants per operated
vertebra (implant density) leads to a better outcome in the treatment of
idiopathic scoliosis. The hypothesis was that implant density is
not associated with patient-reported outcomes, the correction of
the curve or the rate of reoperation. A total of 328 patients with idiopathic scoliosis, aged between
ten and 20 years at the time of surgery, were identified in the
Swedish spine register (Swespine) and had patient reported outcomes
including the Scoliosis Research Society 22r instrument (SRS-22r)
score, EuroQol 5 dimensions quality of life, 3 level (EQ-5D-3L)
score and a Viual Analogue Score (VAS) for back pain, at a mean
follow-up of 3.1 years and reoperation data at a mean follow-up
of 5.5 years. Implant data and the correction of the curve were
assessed from radiographs, preoperatively and a mean of 1.9 years
postoperatively. The patients were divided into tertiles based on
implant density. Data were analyzed with analysis of variance, logistic
regression or log-rank test. Some analyses were adjusted for gender,
age at the time of surgery, the flexibility of the major curve and
follow-up.Aims
Patients and Methods
In two centres in Korea 350 patients with a diagnosis of tuberculosis of the
Tuberculosis (TB) remains endemic in many parts
of the developing world and is increasingly seen in the developed world
due to migration. A total of 1.3 million people die annually from
the disease. Spinal TB is the most common musculoskeletal manifestation,
affecting about 1 to 2% of all cases of TB. The coexistence of HIV,
which is endemic in some regions, adds to the burden and the complexity
of management. This review discusses the epidemiology, clinical presentation,
diagnosis, impact of HIV and both the medical and surgical options
in the management of spinal TB. Cite this article:
Magnetically controlled growing rod (MCGR) systems use non-invasive
spinal lengthening for the surgical treatment of early-onset scoliosis
(EOS). The primary aim of this study was to evaluate the performance
of these devices in the prevention of progression of the deformity.
A secondary aim was to record the rate of complications. An observational study of 31 consecutive children with EOS, of
whom 15 were male, who were treated between December 2011 and October
2017 was undertaken. Their mean age was 7.7 years (2 to 14). The
mean follow-up was 47 months (24 to 69). Distractions were completed
using the tailgating technique. The primary outcome measure was
correction of the radiographic deformity. Secondary outcomes were
growth, functional outcomes and complication rates.Aims
Patients and Methods
The aim of this study was to report a retrospective, consecutive
series of patients with adolescent idiopathic scoliosis (AIS) who
were treated with posterior minimally invasive surgery (MIS) with
a mean follow-up of two years ( We prospectively collected the data of 70 consecutive patients
with AIS treated with MIS using three incisions and a muscle-splitting
approach by a single surgeon between June 2013 and February 2016
and these were retrospectively reviewed. There were eight male and
62 female patients with a mean age of 15 years (Aims
Patients and Methods
This study of patients with osteoarthritis (OA) of the hip aimed to: 1) characterize the contribution of the hip, spinopelvic complex, and lumbar spine when moving from the standing to the sitting position; 2) assess whether abnormal spinopelvic mobility is associated with worse symptoms; and 3) identify whether spinopelvic mobility can be predicted from static anatomical radiological parameters. A total of 122 patients with end-stage OA of the hip awaiting total hip arthroplasty (THA) were prospectively studied. Patient-reported outcome measures (PROMs; Oxford Hip Score, Oswestry Disability Index, and Veterans RAND 12-Item Health Survey Score) and clinical data were collected. Sagittal spinopelvic mobility was calculated as the change from the standing to sitting position using the lumbar lordosis angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic-femoral angle (PFA), and acetabular anteinclination (AI) from lateral radiographs. The interaction of the different parameters was assessed. PROMs were compared between patients with normal spinopelvic mobility (10° ≤ ∆PT ≤ 30°) or abnormal spinopelvic mobility (stiff: ∆PT < ± 10°; hypermobile: ∆PT > ± 30°). Multiple regression and receiver operating characteristic (ROC) curve analyses were used to test for possible predictors of spinopelvic mobility.Aims
Patients and Methods
The primary aim of this study was to evaluate the performance
and safety of magnetically controlled growth rods in the treatment
of early onset scoliosis. Secondary aims were to evaluate the clinical
outcome, the rate of further surgery, the rate of complications,
and the durability of correction. We undertook an observational prospective cohort study of children
with early onset scoliosis, who were recruited over a one-year period
and followed up for a minimum of two years. Magnetically controlled
rods were introduced in a standardized manner with distractions
performed three-monthly thereafter. Adverse events which were both related
and unrelated to the device were recorded. Ten children, for whom
relevant key data points (such as demographic information, growth
parameters, Cobb angles, and functional outcomes) were available,
were recruited and followed up over the period of the study. There
were five boys and five girls. Their mean age was 6.2 years (2.5
to 10).Aims
Patients and Methods
Meropenem may be an important drug in the treatment of open tibial fractures and chronic osteomyelitis. Therefore, the objective of this study was to describe meropenem pharmacokinetics in plasma, subcutaneous adipose tissue (SCT), and cancellous bone using microdialysis in a porcine model. Six female pigs were assigned to receive 1000 mg of meropenem intravenously over five minutes. Measurements of meropenem were obtained from plasma, SCT, and cancellous bone for eight hours thereafter. Microdialysis was applied for sampling in solid tissues. The meropenem concentrations were determined using ultra-high-performance liquid chromatography.Objectives
Methods
There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting terminology and definitions of new concepts that further confuse the topic. In 2017, the concept of a Hip-Spine Workgroup was created with the first meeting held at the American Academy of Orthopedic Surgeons Annual Meeting in 2018. The goal of this workgroup was to first help standardize terminology across the literature so that as a topic, multiple groups could produce literature that is immediately understandable and applicable. This consensus review from the Hip-Spine Workgroup aims to simplify the spinopelvic relationship, offer hip surgeons a concise summary of available literature, and select common terminology approved by both hip surgeons and spine surgeons for future research. Cite this article:
Patients may present with concurrent symptomatic osteoarthritis (OA) of the hip and degenerative disorders of the lumbar spine, with surgical treatment being indicated for both. Whether arthroplasty of the hip or spinal surgery should be performed first remains uncertain. Clinical scenarios were devised for a survey asking the preferred order of surgery and the rationale for this decision for five fictional patients with both OA of the hip and degenerative lumbar disorders. These were symptomatic OA of the hip and: 1) lumbar spinal stenosis with neurological claudication; 2) lumbar degenerative spondylolisthesis with leg pain; 3) lumbar disc herniation with leg weakness; 4) lumbar scoliosis with back pain; and 5) thoracolumbar disc herniation with myelopathy. This survey was sent to 110 members of The Hip Society and 101 members of the Scoliosis Research Society. The choices of the surgeons were compared among scenarios and between surgical specialties using the chi-squared test. The free-text comments were analyzed using text-mining.Aims
Materials and Methods
During revision procedures for aseptic reasons, there remains a suspicion that failure may have been the result of an undetected subclinical infection. However, there is little evidence available in the literature about unexpected positive results in presumed aseptic revision spine surgery. The aims of our study were to estimate the prevalence of unexpected positive culture using sonication and to evaluate clinical characteristics of these patients. All patients who underwent a revision surgery after instrumented spinal surgery at our institution between July 2014 and August 2016 with spinal implants submitted for sonication were retrospectively analyzed. Only revisions presumed as aseptic are included in the study. During the study period, 204 spinal revisions were performed for diagnoses other than infection. In 38 cases, sonication cultures were not obtained, leaving a study cohort of 166 cases. The mean age of the cohort was 61.5 years (Aims
Patients and Methods
This study aimed to analyze the correlation between transverse
process (TP) fractures of the fourth (L4) and fifth (L5) lumbar
vertebrae and biomechanical and haemodynamic stability in patients
with a pelvic ring injury, since previous data are inconsistent. The study is a retrospective matched-pair analysis of patients
with a pelvic fracture according to the modified Tile AO Müller
and the Young and Burgess classification who presented to a level
1 trauma centre between January 2005 and December 2014.Aims
Patients and Methods
The aim of this study was to quantify the risk of developing cancer from the exposure to radiation associated with surgery to correct limb deformities in children. A total of 35 children were studied. There were 19 girls and 16 boys. Their mean age was 11.9 years (2 to 18) at the time of surgery. Details of the radiological examinations were recorded during gradual correction using a Taylor Spatial Frame. The dose area product for each radiograph was obtained from the Computerised Radiology Information System database. The effective dose in millisieverts (mSv) was calculated using conversion coefficients for the anatomical area. The lifetime risk of developing cancer was calculated using government-approved Health Protection Agency reports, accounting for the age and gender of the child.Aims
Patients and Methods
Concurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients with spine fusions can increase the risk of dislocation risk after THA. We identified 84 patients (97 THAs) between 1998 and 2015 who had undergone spinal fusion prior to primary THA. Patients were stratified into three groups depending on the length of lumbar fusion and whether or not the sacrum was involved. Mean age was 71 years (40 to 87) and 54 patients (56%) were female. The mean body mass index (BMI) was 30 kg/m2 (19 to 45). Mean follow-up was six years (2 to 17). Patients were 1:2 matched to patients with primary THAs without spine fusion. Hazard ratios (HR) were calculated.Aims
Patients and Methods
The glenohumeral joint is the most frequently dislocated articulation, but possibly due to the lower prevalence of posterior shoulder dislocations, approximately 50% to 79% of posterior glenohumeral dislocations are missed at initial presentation. The aim of this study was to systematically evaluate the most recent evidence involving the aetiology of posterior glenohumeral dislocations, as well as the diagnosis and treatment. A systematic search was conducted using PubMed (MEDLINE), Web of Science, Embase, and Cochrane (January 1997 to September 2017), with references from articles also evaluated. Studies reporting patients who experienced an acute posterior glenohumeral joint subluxation and/or dislocation, as well as the aetiology of posterior glenohumeral dislocations, were included.Aims
Materials and Methods
The aim of this systematic literature review was to assess the clinical level of evidence of commercially available demineralised bone matrix (DBM) products for their use in trauma and orthopaedic related surgery. A total of 17 DBM products were used as search terms in two available databases: Embase and PubMed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses statement. All articles that reported the clinical use of a DBM-product in trauma and orthopaedic related surgery were included.Objectives
Methods