Metabolic syndrome and low-grade systemic inflammation are associated with knee osteoarthritis (OA), but the relationships between these factors and OA in other synovial joints are unclear. The aim of this study was to determine if a high-fat/high-sucrose (HFS) diet results in OA-like joint damage in the shoulders, knees, and hips of rats after induction of obesity, and to identify potential joint-specific risks for OA-like changes. A total of 16 male Sprague-Dawley rats were allocated to either the diet-induced obesity group (DIO, 40% fat, 45% sucrose, n = 9) or a chow control diet (n = 7) for 12 weeks. At sacrifice, histological assessments of the shoulder, hip, and knee joints were performed. Serum inflammatory mediators and body composition were also evaluated. The total Mankin score for each animal was assessed by adding together the individual Modified Mankin scores across all three joints. Linear regression modelling was conducted to evaluate predictive relationships between serum mediators and total joint damage.Objectives
Methods
The treatment of osteoporotic fractures is a major challenge, and the enhancement of healing is critical as a major goal in modern fracture management. Most osteoporotic fractures occur at the metaphyseal bone region but few models exist and the healing is still poorly understood. A systematic review was conducted to identify and analyse the appropriateness of current osteoporotic metaphyseal fracture animal models. A literature search was performed on the Pubmed, Embase, and Web of Science databases, and relevant articles were selected. A total of 19 studies were included. Information on the animal, induction of osteoporosis, fracture technique, site and fixation, healing results, and utility of the model were extracted.Objectives
Materials and Methods
In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year.Objectives
Patients and Methods
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 biomechanical A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired Objectives
Materials and Methods
We sought to determine whether specific characteristics
of vertebral fractures in elderly men are associated with low bone
mineral density (BMD) and osteoporosis. Mister osteoporosis Sweden is a population based cohort study
involving 3014 men aged 69 to 81 years. Of these, 1427 had readable
lateral radiographs of the thoracic and lumbar spine. Total body
(TB) BMD (g/cm²) and total right hip (TH) BMD were measured by dual
energy x-ray absorptiometry. The proportion of men with osteoporosis
was calculated from TH BMD. There were 215 men (15.1%) with a vertebral
fracture. Those with a fracture had lower TB BMD than those without
(p <
0.001). Among men with a fracture, TB BMD was lower in those
with more than three fractures (p = 0.02), those with biconcave
fractures (p = 0.02) and those with vertebral body compression of
>
42% (worst quartile) (p = 0.03). The mean odds ratio (OR) for
having osteoporosis when having any type of vertebral fracture was
6.1 (95% confidence interval (CI) 3.9 to 9.5) compared with those
without a fracture. A combination of more than three fractures and
compression in the worst quartile had a mean OR of 114.2 (95% CI
6.7 to 1938.3) of having osteoporosis compared with those without
a fracture. We recommend BMD studies to be undertaken in these subcohorts
of elderly men with a vertebral fracture. Cite this article: 2015;97-B:1106–10.
Although vertebroplasty is very effective for relieving acute pain from an osteoporotic vertebral compression fracture, not all patients who undergo vertebroplasty receive the same degree of benefit from the procedure. In order to identify the ideal candidate for vertebroplasty, pre-operative prognostic demographic or clinico-radiological factors need to be identified. The objective of this study was to identify the pre-operative prognostic factors related to the effect of vertebroplasty on acute pain control using a cohort of surgically and non-surgically managed patients. Patients with single-level acute osteoporotic vertebral compression fracture at thoracolumbar junction (T10 to L2) were followed. If the patients were not satisfied with acute pain reduction after a three-week conservative treatment, vertebroplasty was recommended. Pain assessment was carried out at the time of diagnosis, as well as three, four, six, and 12 weeks after the diagnosis. The effect of vertebroplasty, compared with conservative treatment, on back pain (visual analogue score, VAS) was analysed with the use of analysis-of-covariance models that adjusted for pre-operative VAS scores.Objectives
Patients and Methods
We wished to assess the feasibility of a future randomised controlled
trial of parathyroid hormone (PTH) supplements to aid healing of
trochanteric fractures of the hip, by an open label prospective
feasibility and pilot study with a nested qualitative sub study.
This aimed to inform the design of a future powered study comparing
the functional recovery after trochanteric hip fracture in patients
undergoing standard care, We undertook a pilot study comparing the functional recovery
after trochanteric hip fracture in patients 60 years or older, admitted
with a trochanteric hip fracture, and potentially eligible to be
randomised to either standard care or the administration of subcutaneous
PTH for six weeks. Our desired outcomes were functional testing
and measures to assess the feasibility and acceptability of the
study.Aims
Patients and Methods
Aseptic loosening of the femoral component is
an important indication for revision surgery in unicompartmental knee
replacement (UKR). A new design of femoral component with an additional
peg was introduced for the cemented Oxford UKR to increase its stability.
The purpose of this study was to compare the primary stability of
the two designs of component. Medial Oxford UKR was performed in 12 pairs of human cadaver
knees. In each pair, one knee received the single peg and one received
the twin peg design. Three dimensional micromotion and subsidence
of the component in relation to the bone was measured under cyclical
loading at flexion of 40° and 70° using an optical measuring system.
Wilcoxon matched pairs signed-rank test was performed to detect
differences between the two groups. There was no significant difference in the relative micromotion
(p = 0.791 and 0.380, respectively) and subsidence (p = 0.301 and
0.176, respectively) of the component between the two groups at
both angles of flexion. Both designs of component offered good strength
of fixation in this cadaver study. Cite this article:
This study aims to assess the correlation of CT-based structural
rigidity analysis with mechanically determined axial rigidity in
normal and metabolically diseased rat bone. A total of 30 rats were divided equally into normal, ovariectomized,
and partially nephrectomized groups. Cortical and trabecular bone
segments from each animal underwent micro-CT to assess their average
and minimum axial rigidities using structural rigidity analysis.
Following imaging, all specimens were subjected to uniaxial compression
and assessment of mechanically-derived axial rigidity.Objectives
Methods
The relationship between post-operative bone
density and subsequent failure of total knee replacement (TKR) is
not known. This retrospective study aimed to determine the relationship
between bone density and failure, both overall and according to
failure mechanism. All 54 aseptic failures occurring in 50 patients
from 7760 consecutive primary cemented TKRs between 1983 and 2004
were matched with non-failing TKRs, and 47 failures in 44 patients
involved tibial failures with the matching characteristics of age
(65.1 for failed and 69.8 for non-failed), gender (70.2% female), diagnosis
(93.6% OA), date of operation, bilaterality, pre-operative alignment
(0.4 and 0.3 respectively), and body mass index (30.2 and 30.0 respectively).
In each case, the density of bone beneath the tibial component was assessed
at each follow-up interval using standardised, calibrated radiographs.
Failing knees were compared with controls both overall and, as a
subgroup analysis, by failure mechanism. Knees were compared with
controls using univariable linear regression. Significant and continuous elevation in tibial density was found
in knees that eventually failed by medial collapse (p <
0.001)
and progressive radiolucency (p <
0.001) compared with controls,
particularly in the medial region of the tibia. Knees failing due
to ligamentous instability demonstrated an initial decline in density
(p = 0.0152) followed by a non-decreasing density over time (p =
0.034 for equivalence). Non-failing knees reported a decline in
density similar to that reported previously using dual-energy x-ray
absorptiometry (DEXA). Differences between failing and non-failing
knees were observable as early as two months following surgery.
This tool may be used to identify patients at risk of failure following
TKR, but more validation work is needed. Cite this article:
We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p <
0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery.
The December 2013 Research Roundup360 looks at: Inflammation implicated in FAI; Ponseti and effective teaching; Unicompartmental knee design and tibial strain; Bisphosphonates and fracture healing; Antibiosis in cement; Zoledronic acid improves primary stability in revision?; Osteoporotic fractures revisited; and electroarthrography for monitoring of cartilage degeneration
The purpose of this study was to identify changing
trends in the pattern of distribution of the type and demographics
of fractures of the hip in the elderly between 2001 and 2010. A
retrospective cross-sectional comparison was conducted between 179
fractures of the hip treated in 2001, 357 treated in 2006 and 454
treated in 2010. Patients aged <
60 years and those with pathological
and peri-prosthetic fractures were excluded. Fractures were classified
as stable extracapsular, unstable extracapsular or intracapsular
fractures. The mean age of the 179 patients (132 women (73.7%)) treated
in 2001 was 80.8 years (60 to 96), 81.8 years (61 to 101) in the
357 patients (251 women (70.3%)) treated in 2006 and 82.0 years
(61 to 102) in the 454 patients (321 women (70.1%)) treated in 2010
(p = 0.17). There was no difference in the gender distribution between
the three study years (p = 0.68). The main finding was a steep rise in the proportion of unstable
peritrochanteric fractures. The proportion of unstable extracapsular
fractures was 32% (n = 57) in 2001, 35% (n = 125) in 2006 and 45%
(n = 204) in 2010 (p <
0.001). This increase was not significant
in patients aged between 60 and 69 years (p = 0.84), marginally
significant in those aged between 70 and 79 years (p = 0.04) and
very significant in those aged >
80 years (p <
0.001). The proportion
of intracapsular fractures did not change (p = 0.94). At present, we face not only an increasing number of fractures
of the hip, but more demanding and complex fractures in older patients
than a decade ago. This study does not provide an explanation for
this change. Cite this article:
The June 2013 Hip &
Pelvis Roundup360 looks at: failure in metal-on-metal arthroplasty; minimal hip approaches; whether bisphosphonates improve femoral bone stock following arthroplasty; whether more fat means more operative time; surgical infection; vascularised fibular graft for osteonecrosis; subclinical SUFE; and dentists, hips and antibiotics.
We investigated a new intramedullary locking
nail that allows the distal interlocking screws to be locked to
the nail. We compared fixation using this new implant with fixation
using either a conventional nail or a locking plate in a laboratory
simulation of an osteoporotic fracture of the distal femur. A total
of 15 human cadaver femora were used to simulate an AO 33-A3 fracture
pattern. Paired specimens compared fixation using either a locking
or non-locking retrograde nail, and using either a locking retrograde
nail or a locking plate. The constructs underwent cyclical loading
to simulate single-leg stance up to 125 000 cycles. Axial and torsional
stiffness and displacement, cycles to failure and modes of failure
were recorded for each specimen. When compared with locking plate
constructs, locking nail constructs had significantly longer mean
fatigue life (75 800 cycles ( The new locking retrograde femoral nail showed better stiffness
and fatigue life than locking plates, and superior fatigue life
to non-locking nails, which may be advantageous in elderly patients. Cite this article:
The osteoinductive properties of demineralised
bone matrix have been demonstrated in animal studies. However, its therapeutic
efficacy has yet to be proven in humans. The clinical properties
of AlloMatrix, an injectable calcium-based demineralised bone matrix
allograft, were studied in a prospective randomised study of 50
patients with an isolated unstable distal radial fracture treated
by reduction and Kirschner (K-) wire fixation. A total of 24 patients
were randomised to the graft group (13 men and 11 women, mean age
42.3 years (20 to 62)) and 26 to the no graft group (8 men and 18
women, mean age 45.0 years (17 to 69)). At one, three, six and nine weeks, and six and 12 months post-operatively,
patients underwent radiological evaluation, assessments for range
of movement, grip and pinch strength, and also completed the Disabilities
of Arm, Shoulder and Hand questionnaire. At one and six weeks and
one year post-operatively, bone mineral density evaluations of both
wrists were performed. No significant difference in wrist function and speed of recovery,
rate of union, complications or bone mineral density was found between
the two groups. The operating time was significantly higher in the
graft group (p = 0.004). Radiologically, the reduction parameters
remained similar in the two groups and all AlloMatrix extraosseous leakages
disappeared after nine weeks. This prospective randomised controlled trial did not demonstrate
a beneficial effect of AlloMatrix demineralised bone matrix in the
treatment of this category of distal radial fractures treated by
K-wire fixation. Cite this article:
Stress shielding resulting in diminished bone
density following total knee replacement (TKR) may increase the
risk of migration and loosening of the prosthesis. This retrospective
study was designed to quantify the effects of the method of fixation
on peri-prosthetic tibial bone density beneath cemented and uncemented
tibial components of similar design and with similar long-term survival
rates. Standard radiographs taken between two months and 15 years
post-operatively were digitised from a matched group of TKRs using
cemented (n = 67) and uncemented (n = 67) AGC tibial prostheses.
Digital radiograph densitometry was used to quantify changes in
bone density over time. Age, length of follow-up, gender, body mass
index and alignment each significantly influenced the long-term
pattern of peri-prosthetic bone density. Similar long-term changes
in density irrespective of the method of fixation correlated well
with the high rate of survival of this TKR at 20 years, and suggest
that cemented and uncemented fixation are both equally viable. Cite this article:
The purpose of this study was to evaluate the
risk of late displacement after the treatment of distal radial fractures with
a locking volar plate, and to investigate the clinical and radiological
factors that might correlate with re-displacement. From March 2007
to October 2009, 120 of an original cohort of 132 female patients
with unstable fractures of the distal radius were treated with a
volar locking plate, and were studied over a follow-up period of
six months. In the immediate post-operative and final follow-up
radiographs, late displacement was evaluated as judged by ulnar
variance, radial inclination, and dorsal angulation. We also analysed
the correlation of a variety of clinical and radiological factors
with re-displacement. Ulnar variance was significantly overcorrected
(p <
0.001) while radial inclination and dorsal angulation were
undercorrected when compared statistically (p <
0.001) with the unaffected
side in the immediate post-operative stage. During follow-up, radial
shortening and dorsal angulation progressed statistically, but none
had a value beyond the acceptable range. Bone mineral density measured
at the proximal femur and the position of the screws in the subchondral
region, correlated with slight progressive radial shortening, which
was not clinically relevant. Volar locking plating of distal radial fractures is a reliable
form of treatment without substantial late displacement. Cite this article: