This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images. The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models. The Hounsfield units of each voxel were converted into density (mg/cm3). Then, a deep-learning model trained by manual landmark selection of 315 cases was developed to select the landmarks at the proximal femur to rotate the CT volume to the neutral position. Finally, the CT volume of the femur was projected onto the coronal plane, and the areal BMD of the proximal femur (CT-aBMD) was quantified. CT-aBMD correlated to DXA-BMD, and a receiver operating characteristic (ROC) analysis quantified the accuracy in diagnosing osteoporosis.Aims
Methods
Type 2 diabetes mellitus (T2DM) impairs bone strength and is a significant risk factor for hip fracture, yet currently there is no reliable tool to assess this risk. Most risk stratification methods rely on bone mineral density, which is not impaired by diabetes, rendering current tests ineffective. CT-based finite element analysis (CTFEA) calculates the mechanical response of bone to load and uses the yield strain, which is reduced in T2DM patients, to measure bone strength. The purpose of this feasibility study was to examine whether CTFEA could be used to assess the hip fracture risk for T2DM patients. A retrospective cohort study was undertaken using autonomous CTFEA performed on existing abdominal or pelvic CT data comparing two groups of T2DM patients: a study group of 27 patients who had sustained a hip fracture within the year following the CT scan and a control group of 24 patients who did not have a hip fracture within one year. The main outcome of the CTFEA is a novel measure of hip bone strength termed the Hip Strength Score (HSS).Aims
Methods
To evaluate whether an ultra-low-dose CT protocol can diagnose
selected limb fractures as well as conventional CT (C-CT). We prospectively studied 40 consecutive patients with a limb
fracture in whom a CT scan was indicated. These were scanned using
an ultra-low-dose CT Reduced Effective Dose Using Computed Tomography
In Orthopaedic Injury (REDUCTION) protocol. Studies from 16 selected
cases were compared with 16 C-CT scans matched for age, gender and
type of fracture. Studies were assessed for diagnosis and image
quality. Descriptive and reliability statistics were calculated.
The total effective radiation dose for each scanned site was compared.Aims
Patients and Methods
The clinical utility of routine cross sectional imaging of the
abdomen and pelvis in the screening and surveillance of patients
with primary soft-tissue sarcoma of the extremities for metastatic
disease is controversial, based on its questionable yield paired
with concerns regarding the risks of radiation exposure, cost, and
morbidity resulting from false positive findings. Through retrospective review of 140 patients of all ages (mean
53 years; 2 to 88) diagnosed with soft-tissue sarcoma of the extremity
with a mean follow-up of 33 months (0 to 291), we sought to determine
the overall incidence of isolated abdominopelvic metastases, their
temporal relationship to chest involvement, the rate of false positives, and
to identify disparate rates of metastases based on sarcoma subtype.Objectives
Methods
We investigated the development of CT-based bony
radiological parameters associated with femoroacetabular impingement
(FAI) in a paediatric and adolescent population with no known orthopaedic
hip complaints. We retrospectively reformatted and reoriented
225 abdominal CTs into standardised CT pelvic images with neutral
pelvic tilt and inclination (244 female and 206 male hips) in patients
ranging from two to 19 years of age (mean 10.4 years). The Tönnis
angle, acetabular depth ratio, lateral centre–edge angle, acetabular
version and α-angle were assessed. Acetabular measurements demonstrated increased acetabular coverage
with age and/or progressive ossification of the acetabulum. The α-angle
decreased with age and/or progressive cortical bone development
and resultant narrowing of the femoral neck. Cam and pincer morphology
occurred as early as ten and 12 years of age, respectively, and
their prevalence in the adolescent patient population is similar
to that reported in the adult literature. Future aetiological studies
of FAI will need to focus on the early adolescent population. Cite this article:
A total of 157 hindquarter amputations were carried
out in our institution during the last 30 years. We have investigated
the reasons why this procedure is still required and the outcome.
This operation was used as treatment for 13% of all pelvic bone
sarcomas. It was curative in 140 and palliative in 17, usually to
relieve pain. There were 90 primary procedures (57%) with the remaining
67 following the failure of previous operations to control the disease
locally. The indication for amputation in primary disease was for
large tumours for which limb-salvage surgery was no longer feasible.
The peri-operative mortality was 1.3% (n = 2) and major complications
of wound healing or infection arose in 71 (45%) patients. The survival
at five years after hindquarter amputation with the intent to cure
was 45%, and at ten years 38%. Local recurrence occurred in 23 patients
(15%). Phantom pain was a significant problem, and only 20% used
their prosthesis regularly. Functional scores were a mean of 57%.
With careful patient selection the oncological results and functional outcomes
of hindquarter amputation justify its continued use. Cite this article:
The August 2012 Spine Roundup360 looks at: neural tissue and polymerising bone cement; a new prognostic score for spinal metastases from prostatic tumours; recovery after spinal decompression; spinal tuberculosis; unintended durotomy at spinal surgery; how carrying a load on your head can damage the cervical spine; and how age changes your lumbar spine.
We performed a prospective study to examine the
influence of the patient’s position on the location of the abdominal
organs, to investigate the possibility of a true lateral approach
for transforaminal endoscopic lumbar discectomy. Pre-operative abdominal
CT scans were taken in 20 patients who underwent endoscopic lumbar discectomy.
Axial images in parallel planes of each intervertebral disc from
L1 to L5 were achieved in both supine and prone positions. The most
horizontal approach angles possible to avoid injury to the abdominal
organs were measured. The results demonstrated that the safe approach
angles were significantly less (i.e., more horizontal) in the prone
than in the supine position. Obstacles to a more lateral approach
were mainly the liver, the spleen and the kidneys at L1/2 (39 of
40, 97.5%) and L2/3 (28 of 40, 70.0%), and the intestines at L3/4
(33 of 40, 82.5%) and L4/5 (30 of 30, 100%). A true lateral approach
from each side was possible for 30 of the 40 discs at L3/4 (75%)
and 23 of the 30 discs at L4/5 (76.7%). We concluded that a more
horizontal approach for transforaminal endoscopic lumbar discectomy
is possible in the prone position but not in the supine. Prone abdominal
CT is more helpful in determining the trajectory of the endoscope.
While a true lateral approach is feasible in many patients, our
study shows it is not universally applicable.
We retrospectively reviewed 71 histopathologically-confirmed bone and soft-tissue metastases of unknown origin at presentation. In order to identify the site of the primary tumour all 71 cases were examined with conventional procedures, including CT, serum tumour markers, a plain radiograph, ultrasound examination and endoscopic examinations, and 24 of the 71 cases underwent 2-deoxy-2-[F-18] fluoro-D-glucose positron emission tomography (FDG-PET). This detected multiple bone metastases in nine patients and the primary site in 12 of the 24 cases; conventional studies revealed 16 primary tumours. There was no significant difference in sensitivity between FDG-PET and conventional studies. The mean maximal standardised uptake value of the metastatic tumours was significantly higher than that of the primary tumours, which is likely to explain why FDG-PET did not provide better results. It was not superior to conventional procedures in the search for the primary site of bone and soft-tissue metastases; however, it seemed to be useful in the staging of malignancy.
Rupture of an aneurysm of the common iliac artery is a rare cause of pain in the hip. We describe an elderly hypertensive patient with an aneurysmal rupture of the left common iliac artery who presented with unilateral hip pain masquerading as septic arthritis.
Digital radiography is becoming widespread. Accurate pre-operative templating of digital images of the hip traditionally involves positioning a calibration object at its centre. This can be difficult and cause embarrassment. We have devised a method whereby a planar disc placed on the radiographic cassette accounts for the expected magnification. Initial examination of 50 pelvic CT scans showed a mean hip centre distance of 117 mm (79 to 142) above the gluteal skin. Further calculations predicted that a disc of 37.17 mm diameter, placed on the cassette, would appear identical to a 30 mm sphere placed at the level of the centre of the hip as requested by our templating software. We assessed accuracy and reproducibility by ‘reverse calibration’ of 20 radiographs taken three months after hip replacement using simultaneous sphere and disc methods, and a further 20 with a precision disc of accurate size. Even when variations in patient size were ignored, the disc proved more accurate and reliable than the sphere. The technique is reliable, robust, cost effective and acceptable to patients and radiographers. It can easily be used in any radiography department after a few simple calculations and manufacture of appropriately-sized discs.
Iliacus haematoma is a relatively rare condition, which may cause a local compressive neuropathy. It is usually diagnosed in adults with haemophilia or those on anticoagulation treatment and may occur after trauma. We present the case of a healthy 15-year-old boy with a femoral neuropathy due to an iliacus haematoma which resolved following conservative treatment.
We report retrospective and prospective studies to identify the causes of fracture of the femoral neck associated with femoral shaft nailing on the same side. Of a total of 14 neck fractures in a series of 152 shaft nailings, eight were not visible on the initial pelvic radiographs. We used CT scans before and after operation, and fluoroscopy during the procedure in our prospective series, and reviewed
