The aim of this study was to examine whether asymmetric loading
influences macrophage elastase (MMP12) expression in different parts
of a rat tail intervertebral disc and growth plate and if MMP12
expression is correlated with the severity of the deformity. A wedge deformity between the ninth and tenth tail vertebrae
was produced with an Ilizarov-type mini external fixator in 45 female
Wistar rats, matched for their age and weight. Three groups were
created according to the degree of deformity (10°, 30° and 50°).
A total of 30 discs and vertebrae were evaluated immunohistochemically
for immunolocalisation of MMP12 expression, and 15 discs were analysed
by western blot and zymography in order to detect pro- and active
MMP12.Objectives
Methods
This study aimed to evaluate the histological and mechanical features of tendon healing in a rabbit model with second-harmonic-generation (SHG) imaging and tensile testing. A total of eight male Japanese white rabbits were used for this study. The flexor digitorum tendons in their right leg were sharply transected, and then were repaired by intratendinous stitching. At four weeks post-operatively, the rabbits were killed and the flexor digitorum tendons in both right and left legs were excised and used as specimens for tendon healing (n = 8) and control (n = 8), respectively. Each specimen was examined by SHG imaging, followed by tensile testing, and the results of the two testing modalities were assessed for correlation.Objectives
Materials and Methods
The surgical management of ankle arthritis with tibiotalar arthrodesis
is known to alter gait, as compared with normal ankles. The purpose
of this study was to assess post-operative gait function with gait
before arthrodesis. We prospectively studied 20 patients who underwent three-dimensional
gait analysis before and after tibiotalar arthrodesis. Cadence,
step length, walking velocity and total support time were assessed.
Kinetic parameters, including the moment and power of the ankle
in the sagittal plane and hip power were also recorded.Aims
Patients and Methods
This article presents a unified clinical theory
that links established facts about the physiology of bone and homeostasis,
with those involved in the healing of fractures and the development
of nonunion. The key to this theory is the concept that the tissue
that forms in and around a fracture should be considered a specific
functional entity. This ‘bone-healing unit’ produces a physiological
response to its biological and mechanical environment, which leads
to the normal healing of bone. This tissue responds to mechanical
forces and functions according to Wolff’s law, Perren’s strain theory
and Frost’s concept of the “mechanostat”. In response to the local
mechanical environment, the bone-healing unit normally changes with
time, producing different tissues that can tolerate various levels
of strain. The normal result is the formation of bone that bridges
the fracture – healing by callus. Nonunion occurs when the bone-healing
unit fails either due to mechanical or biological problems or a
combination of both. In clinical practice, the majority of nonunions
are due to mechanical problems with instability, resulting in too
much strain at the fracture site. In most nonunions, there is an
intact bone-healing unit. We suggest that this maintains its biological
potential to heal, but fails to function due to the mechanical conditions.
The theory predicts the healing pattern of multifragmentary fractures
and the observed morphological characteristics of different nonunions.
It suggests that the majority of nonunions will heal if the correct
mechanical environment is produced by surgery, without the need
for biological adjuncts such as autologous bone graft. Cite this article:
Matrix metalloproteinases (MMPs), responsible
for extracellular matrix remodelling and angiogenesis, might play
a major role in the response of the growth plate to detrimental
loads that lead to overuse injuries in young athletes. In order
to test this hypothesis, human growth plate chondrocytes were subjected
to mechanical forces equal to either physiological loads, near detrimental
or detrimental loads for two hours. In addition, these cells were
exposed to physiological loads for up to 24 hours. Changes in the
expression of MMPs -2, -3 and -13 were investigated. We found that expression of MMPs in cultured human growth plate
chondrocytes increases in a linear manner with increased duration
and intensity of loading. We also showed for the first time that
physiological loads have the same effect on growth plate chondrocytes
over a long period of time as detrimental loads applied for a short
period. These findings confirm the involvement of MMPs in overuse injuries
in children. We suggest that training programmes for immature athletes
should be reconsidered in order to avoid detrimental stresses and
over-expression of MMPs in the growth plate, and especially to avoid
physiological loads becoming detrimental. Cite this article:
To clarify the asymmetrical ossification of the epiphyseal ring
between the convex and concave sides in patients with adolescent
idiopathic scoliosis (AIS). A total of 29 female patients (mean age, 14.4 years; 11 to 18)
who underwent corrective surgery for AIS (Lenke type 1 or 2) were
included in our study. In all, 349 vertebrae including 68 apical
vertebrae and 87 end vertebrae in the main thoracic (MT) curve and
thoracolumbar/lumbar (TL/L) curve were analysed. Coronal sections
(anterior, middle and posterior) of the vertebral bodies were reconstructed
from pre-operative CT scans (320-row detector; slice thickness,
0.5 mm) and the appearances of the ossification centre in the epiphyseal
ring at four corners were evaluated in three groups; all vertebrae
excluding end vertebrae, apical vertebrae and end vertebrae. The appearance
rates of the ossification centre at the concave and convex sides
were calculated and compared.Aims
Patients and Methods
Previous genome-wide association studies (GWAS) have reported significant association of the single nucleotide polymorphism (SNP) rs8044769 in the fat mass and obesity-associated gene (FTO) with osteoarthritis (OA) risk in European populations. However, these findings have not been confirmed in Chinese populations. We systematically genotyped rs8044769 and evaluated the association between the genetic variants and OA risk in a case-controlled study including 196 OA cases and 442 controls in a northern Chinese population. Genotyping was performed using the Sequenom MassARRAY iPLEX platform.Objectives
Methods
The continual cycle of bone formation and resorption
is carried out by osteoblasts, osteocytes, and osteoclasts under
the direction of the bone-signaling pathway. In certain situations
the host cycle of bone repair is insufficient and requires the assistance
of bone grafts and their substitutes. The fundamental properties
of a bone graft are osteoconduction, osteoinduction, osteogenesis,
and structural support. Options for bone grafting include autogenous
and allograft bone and the various isolated or combined substitutes
of calcium sulphate, calcium phosphate, tricalcium phosphate, and
coralline hydroxyapatite. Not all bone grafts will have the same
properties. As a result, understanding the requirements of the clinical
situation and specific properties of the various types of bone grafts
is necessary to identify the ideal graft. We present a review of
the bone repair process and properties of bone grafts and their
substitutes to help guide the clinician in the decision making process. Cite this article:
During open orthopaedic surgery, joints may be exposed to air, potentially leading to cartilage drying and chondrocyte death, however, the long-term effects of joint drying The patellar groove of anaesthetised rats was exposed (sham-operated), or exposed and then subjected to laminar airflow (0.25m/s; 60 minutes) before wounds were sutured and animals recovered. Animals were monitored for up to eight weeks and then sacrificed. Cartilage and chondrocyte properties were studied by histology and confocal microscopy, respectively.Objectives
Methods
Total knee arthroplasty (TKA) is known to lead
to a reduction in periprosthetic bone mineral density (BMD). In theory,
this may lead to migration, instability and aseptic loosening of
the prosthetic components. Bisphosphonates inhibit bone resorption
and may reduce this loss in BMD. We hypothesised that treatment
with bisphosphonates and calcium would lead to improved BMD and
clinical outcomes compared with treatment with calcium supplementation
alone following TKA. A total of 26 patients, (nine male and 17 female,
mean age 67 years) were prospectively randomised into two study
groups: alendronate and calcium (bisphosphonate group, n = 14) or calcium
only (control group, n = 12). Dual energy X-ray absorptiometry (DEXA)
measurements were performed post-operatively, and at three months,
six months, one, two, four, and seven years post-operatively. Mean femoral metaphyseal BMD was significantly higher in the
bisphosphonate group compared with controls, up to four years following
surgery in some areas of the femur (p = 0.045). BMD was observed
to increase in the lateral tibial metaphysis in the bisphosphonate
group until seven years (p = 0.002), and was significantly higher than
that observed in the control group throughout (p = 0.024). There
were no significant differences between the groups in the central
femoral metaphyseal, tibial medial metaphyseal or diaphyseal regions
of interest (ROI) of either the femur or tibia. Bisphosphonate treatment after TKA may be of benefit for patients
with poor bone quality. However, further studies with a larger number
of patients are necessary to assess whether this is clinically beneficial. Cite this article:
Recently, the use of metal-on-metal articulations
in total hip arthroplasty (THA) has led to an increase in adverse
events owing to local soft-tissue reactions from metal ions and
wear debris. While the majority of these implants perform well,
it has been increasingly recognised that a small proportion of patients
may develop complications secondary to systemic cobalt toxicity
when these implants fail. However, distinguishing true toxicity
from benign elevations in cobalt ion levels can be challenging. The purpose of this two part series is to review the use of cobalt
alloys in THA and to highlight the following related topics of interest:
mechanisms of cobalt ion release and their measurement, definitions
of pathological cobalt ion levels, and the pathophysiology, risk factors
and treatment of cobalt toxicity. Historically, these metal-on-metal
arthroplasties are composed of a chromium-cobalt articulation. The release of cobalt is due to the mechanical and oxidative
stresses placed on the prosthetic joint. It exerts its pathological
effects through direct cellular toxicity. This manuscript will highlight the pathophysiology of cobalt
toxicity in patients with metal-on-metal hip arthroplasties. Take home message: Patients with new or evolving hip symptoms
with a prior history of THA warrant orthopaedic surgical evaluation.
Increased awareness of the range of systemic symptoms associated
with cobalt toxicity, coupled with prompt orthopaedic intervention, may
forestall the development of further complications. Cite this article:
The August 2015 Children’s orthopaedics Roundup360 looks at: Learning the Pavlik; MRI and patellar instability; Cerebral palsy and hip dysplasia; ‘Pick your poison’: elastic nailing under the spotlight; Club feet and surgery; Donor site morbidity in vascularised fibular grafting; Cartilage biochemistry with hip dysplasia; SUFE and hip decompression: a good option?
Ligaments which heal spontaneously have a healing process that
is similar to skin wound healing. Menopause impairs skin wound healing
and may likewise impair ligament healing. Our purpose in this study
was to investigate the effect of surgical menopause on ligament
healing in a rabbit medial collateral ligament model. Surgical menopause was induced with ovariohysterectomy surgery
in adult female rabbits. Ligament injury was created by making a
surgical gap in the midsubstance of the medial collateral ligament.
Ligaments were allowed to heal for six or 14 weeks in the presence
or absence of oestrogen before being compared with uninjured ligaments. Molecular
assessment examined the messenger ribonucleic acid levels for collagens,
proteoglycans, proteinases, hormone receptors, growth factors and
inflammatory mediators. Mechanical assessments examined ligament
laxity, total creep strain and failure stress.Objectives
Methods
Accurate, reproducible outcome measures are essential
for the evaluation of any orthopaedic procedure, in both clinical
practice and research. Commonly used patient-reported outcome measures (PROMs) have
drawbacks such as ‘floor’ and ‘ceiling’ effects, limitations of
worldwide adaptability and an inability to distinguish pain from
function. They are also unable to measure the true outcome of an
intervention rather than a patient’s perception of that outcome. Performance-based functional outcome tools may address these
problems. It is important that both clinicians and researchers are
aware of these measures when dealing with high-demand patients,
using a new intervention or implant, or testing a new rehabilitation
protocol. This article provides an overview of some of the clinically-validated
performance-based functional outcome tools used in the assessment
of patients undergoing hip and knee surgery. 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:
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.
In 2012 we reviewed a consecutive series of 92
uncemented THRs performed between 1986 and 1991 at our institution
using the CLS Spotorno stem, in order to assess clinical outcome
and radiographic data at a minimum of 21 years. The series comprised
92 patients with a mean age at surgery of 59.6 years (39 to 77)
(M:F 43;49). At the time of this review, seven (7.6%) patients had died and
two (2.2%) were lost to follow-up. The 23-year Kaplan–Meier survival
rates were 91.5% (95% confidence intervals (CI) 85.4% to 97.6%;
55 hips at risk) and 80.3% (95% CI, 71.8% to 88.7%; 48 hips at risk)
respectively, with revision of the femoral stem or of any component
as endpoints. At the time of this review, 76 patients without stem
revision were assessed clinically and radiologically (mean follow-up
24.0 years (21.5 to 26.5)). For the 76 unrevised hips the mean Harris
hip score was 87.1 (65 to 97). Femoral osteolysis was detected in
five hips (6.6%) only in Gruen zone 7. Undersized stems were at
higher risk of revision owing to aseptic loosening (p = 0.0003).
Patients implanted with the stem in a varus position were at higher risk
of femoral cortical hypertrophy and thigh pain (p = 0.0006 and p
= 0.0007, respectively). In our study, survival, clinical outcome and radiographic data
remained excellent in the third decade after implantation. Nonetheless,
undersized stems were at higher risk of revision owing to aseptic
loosening. Cite this article:
Tendinopathy is a debilitating musculoskeletal
condition which can cause significant pain and lead to complete rupture
of the tendon, which often requires surgical repair. Due in part
to the large spectrum of tendon pathologies, these disorders continue
to be a clinical challenge. Animal models are often used in this
field of research as they offer an attractive framework to examine
the cascade of processes that occur throughout both tendon pathology and
repair. This review discusses the structural, mechanical, and biological
changes that occur throughout tendon pathology in animal models,
as well as strategies for the improvement of tendon healing. Cite this article:
