Loosening is a well-known complication in the fixation of fractures using devices such as locking plates or unilateral fixators. It is believed that high strains in the bone at the bone-screw interface can initiate loosening, which can result in infection, and further loosening. Here, we present a new theory of loosening of implants. The time-dependent response of bone subjected to loads results in interfacial deformations in the bone which accumulate with cyclical loading and thus accentuates loosening. We used an ‘ideal’ bone-screw system, in which the screw is subjected to cyclical lateral loads and trabecular bone is modelled as non-linear viscoelastic and non-linear viscoelastic-viscoplastic material, based on recent experiments, which we conducted.Aims
Methods
The aim of this study was to investigate the impact of maturity status at the time of surgery on final spinal height in patients with an adolescent idiopathic scoliosis (AIS) using the spine-pelvic index (SPI). The SPI is a self-control ratio that is independent of age and maturity status. The study recruited 152 female patients with a Lenke 1 AIS. The additional inclusion criteria were a thoracic Cobb angle between 45° and 70°, Risser 0 to 1 or 3 to 4 at the time of surgery, and follow-up until 18 years of age or Risser stage 5. The patients were stratified into four groups: Risser 0 to 1 and selective fusion surgery (Group 1), Risser 0 to 1 and non-selective fusion (Group 2), Risser 3 to 4 and selective fusion surgery (Group 3), and Risser 3 to 4 and non-selective fusion (Group 4). The height of spine at follow-up (HOSf) and height of pelvis at follow-up (HOPf) were measured and the predicted HOS (pHOS) was calculated as 2.22 (SPI) × HOPf. One-way analysis of variance (ANOVA) was performed for statistical analysis.Aims
Patients and Methods
The surgical treatment of tuberculosis (TB) of the spine consists
of debridement and reconstruction of the anterior column. Loss of
correction is the most significant challenge. Our aim was to report
the outcome of single-stage posterior surgery using bone allografts
in the management of this condition. The study involved 24 patients with thoracolumbar TB who underwent
single-stage posterior spinal surgery with a cortical bone allograft
for anterior column reconstruction and posterior instrumentation
between 2008 and 2015. A unilateral approach was used for 21 patients
with active TB, and a bilateral approach with decompression and closing-opening
wedge osteotomy was used for three patients with healed TB.Aims
Patients and Methods
In a multicentre, randomised study of adolescents undergoing
posterior spinal fusion for idiopathic scoliosis, we investigated
the effect of adding gelatine matrix with human thrombin to the
standard surgical methods of controlling blood loss. Patients in the intervention group (n = 30) were randomised to
receive a minimum of two and a maximum of four units of gelatine
matrix with thrombin in addition to conventional surgical methods
of achieving haemostasis. Only conventional surgical methods were
used in the control group (n = 30). We measured the intra-operative
and total blood loss (intra-operative blood loss plus post-operative
drain output).Aims
Patients and Methods
The aim of the study was to compare measures of the quality of
life (QOL) after resection of a chordoma of the mobile spine with
the national averages in the United States and to assess which factors
influenced the QOL, symptoms of anxiety and depression, and coping
with pain post-operatively in these patients. A total of 48 consecutive patients who underwent resection of
a primary or recurrent chordoma of the mobile spine between 2000
and 2015 were included. A total of 34 patients completed a survey
at least 12 months post-operatively. The primary outcome was the
EuroQol-5 Dimensions (EQ-5D-3L) questionnaire. Secondary outcomes were
the Patient-Reported Outcome Measurement Information System (PROMIS)
anxiety, depression and pain interference questionnaires. Data which
were recorded included the indication for surgery, the region of
the tumour, the number of levels resected, the status of the surgical
margins, re-operations, complications, neurological deficit, length
of stay in hospital and rate of re-admission.Aims
Patients and Methods
The aim of this study is to introduce and investigate the efficacy
and feasibility of a new vertebral osteotomy technique, vertebral
column decancellation (VCD), for rigid thoracolumbar kyphotic deformity
(TLKD) secondary to ankylosing spondylitis (AS). We took 39 patients from between January 2009 and January 2013
(26 male, 13 female, mean age 37.4 years, 28 to 54) with AS and
a TLKD who underwent VCD (VCD group) and compared their outcome
with 45 patients (31 male, 14 female, mean age 34.8 years, 23 to
47) with AS and TLKD, who underwent pedicle subtraction osteotomy
(PSO group), according to the same selection criteria. The technique
of VCD was performed at single vertebral level in the thoracolumbar
region of AS patients according to classification of AS kyphotic
deformity. Pre- and post-operative chin-brow vertical angle (CBVA),
sagittal vertical axis (SVA) and sagittal Cobb angle in the thoracolumbar
region were reviewed in the VCD and PSO groups. Intra- , post-operative
and general complications were analysed in both group.Aims
Patients and Methods
Increasing innovation in rapid prototyping (RP)
and additive manufacturing (AM), also known as 3D printing, is bringing
about major changes in translational surgical research. This review describes the current position in the use of additive
manufacturing in orthopaedic surgery. Cite this article:
The sacrum is frequently invaded by a pelvic tumour. The aim
of this study was to review our experience of treating this group
of patients and to identify the feasibility of a new surgical classification
in the management of these tumours. We reviewed 141 patients who, between 2005 and 2014, had undergone
surgical excision of a pelvic tumour with invasion of the sacrum. In a new classification, pelvisacral (Ps) I, II, and III resections
refer to a sagittal osteotomy through the ipsilateral wing of the
sacrum, through the sacral midline, or lateral to the contralateral
sacral foramina, respectively. A Ps a resection describes a pelvic
osteotomy through the ilium and a Ps b resection describes a concurrent
resection of the acetabulum with osteotomies performed through the
pubis and ischium or the pubic symphysis. Within each type, surgical
approaches were standardized to guide resection of the tumour.Aims
Patients and Methods
The use of robots in orthopaedic surgery is an
emerging field that is gaining momentum. It has the potential for significant
improvements in surgical planning, accuracy of component implantation
and patient safety. Advocates of robot-assisted systems describe
better patient outcomes through improved pre-operative planning
and enhanced execution of surgery. However, costs, limited availability,
a lack of evidence regarding the efficiency and safety of such systems
and an absence of long-term high-impact studies have restricted
the widespread implementation of these systems. We have reviewed
the literature on the efficacy, safety and current understanding of
the use of robotics in orthopaedics. Cite this article:
The August 2014 Spine Roundup360 looks at: rhBMP complicates cervical spine surgery; posterior longitudinal ligament revisited; thoracolumbar posterior instrumentation without fusion in burst fractures; risk modelling for VTE events in spinal surgery; the consequences of dural tears in microdiscectomy; trends in revision spinal surgery; radiofrequency denervation likely effective in facet joint pain and hooks optimally biomechanically transition posterior instrumentation.
We describe 13 patients with cerebral palsy and
lordoscoliosis/hyperlordosis of the lumbar spine who underwent a posterior
spinal fusion at a mean age of 14.5 years (10.8 to 17.4) to improve
sitting posture and relieve pain. The mean follow-up was 3.3 years
(2.2 to 6.2). The mean pre-operative lumbar lordosis was 108° (80
to 150°) and was corrected to 62° (43° to
85°); the mean thoracic kyphosis from 17° (-23° to
35°) to 47° (25° to 65°);
the mean scoliosis from 82° (0° to 125°)
to 22° (0° to 40°); the mean pelvic
obliquity from 21° (0° to 38°)
to 3° (0° to 15°); the mean sacral
slope from 79° (54° to 90°) to
50° (31° to 66°). The mean pre-operative
coronal imbalance was 5 cm (0 cm to 8.9 cm) and was corrected to
0.6 cm (0 to 3.2). The mean sagittal imbalance of -8 cm (-16 cm
to 7.8 cm) was corrected to -1.6 cm
(-4 cm to 2.5 cm). The mean operating time was 250 minutes (180
to 360 minutes) and intra-operative blood loss 0.8 of estimated
blood volume (0.3 to 2 estimated blood volume). The mean intensive
care and hospital stay were 3.5 days (2 to 8) and 14.5 days (10
to 27), respectively. Three patients lost a significant amount of
blood intra-operatively and subsequently developed chest or urinary
infections and superior mesenteric artery syndrome. An increased pre-operative lumbar lordosis and sacral slope were
associated with increased peri-operative morbidity: scoliosis and
pelvic obliquity were not. A reduced lumbar lordosis and increased
thoracic kyphosis correlated with better global sagittal balance
at follow-up. All patients and their parents reported excellent
surgical outcomes. Lordoscoliosis and hyperlordosis are associated with significant
morbidity in quadriplegic patients. They are rare deformities and
their treatment is challenging. Sagittal imbalance is the major
component: it can be corrected by posterior fusion of the spine
with excellent functional results. Cite this article:
We compared the accuracy, operating time and radiation exposure
of the introduction of iliosacral screws using O-arm/Stealth Navigation
and standard fluoroscopy. Iliosacral screws were introduced percutaneously into the first
sacral body (S1) of ten human cadavers, four men and six women.
The mean age was 77 years (58 to 85). Screws were introduced using
a standard technique into the left side of S1 using C-Arm fluoroscopy
and then into the right side using O-Arm/Stealth Navigation. The
radiation was measured on the surgeon by dosimeters placed under
a lead thyroid shield and apron, on a finger, a hat and on the cadavers.Aims
Materials and Methods
We report the results of vertebral column resection
(VCR) for paediatric patients with spinal deformity. A total of
49 VCRs in paediatric patients from four university hospitals between
2005 and 2009 with a minimum two-year follow-up were retrospectively
identified. After excluding single hemivertebral resections (n =
25) and VCRs performed for patients with myelomeningocele (n = 6),
as well as spondylectomies performed for tumour (n = 4), there were
14 patients who had undergone full VCR at a mean age of 12.3 years
(6.5 to 17.9). The aetiology was congenital scoliosis in five, neuromuscular
scoliosis in three, congenital kyphosis in two, global kyphosis
in two, adolescent idiopathic scoliosis in one and secondary scoliosis
in one. A total of seven anteroposterior and seven posterolateral approaches
were used. The mean major curve deformity was 86° (67° to 120°) pre-operatively
and 37° (17° to 80°) at the two-year follow-up; correction was a
mean of 54% (18% to 86%) in the anteroposterior and 60% (41% to
70%) in the posterolateral group at the two-year follow-up (p =
0.53). The mean Scoliosis Research Society-24 total scores were
100 (92 to 108) for the anteroposterior and 102 (95 to 105) for
the posterolateral group. There was one paraparesis in the anteroposterior
group necessitating urgent re-decompression, with a full recovery. Patients undergoing VCR are highly satisfied after a successful
procedure.
The December 2015 Spine Roundup360 looks at: Ketamine in scoliosis surgery; Teriparatide in osteoporotic spinal fractures; Trabecular metal in the spine?; Revision surgery a SPORTing chance?; The course of degenerative lumbar spondylolisthesis; Hip or lumbar spine: a common conundrum
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
In the United Kingdom, lower incidences of intraspinal abnormalities
in patients with early onset idiopathic scoliosis have been observed
than in studies in other countries. We aimed to determine the rates
of these abnormalities in United Kingdom patients diagnosed with idiopathic
scoliosis before the age of 11 years. This retrospective study of patients attending an urban scoliosis
clinic identified 71 patients satisfying a criteria of: clinical
diagnosis of idiopathic scoliosis; age of onset ten years and 11 months
or less; MRI screening for intraspinal abnormalities. United Kingdom
census data combined with patient referral data was used to calculate
incidence.Aims
Patients and Methods
