Hydroxyapatite coatings for uncemented fixation in total knee
arthroplasty can theoretically provide a long-lasting biological
interface with the host bone. The objective of this study was to
test this hypothesis with propriety hydroxyapatite, peri-apatite,
coated tibial components using component migration measured with radiostereometric
analysis over two years as an indicator of long-term fixation. A total of 29 patients at two centres received uncemented PA-coated
tibial components and were followed for two years with radiostereometric
analysis exams to quantify the migration of the component.Aims
Patients and Methods
Instability remains a challenging problem in both primary and
revision total hip arthroplasty (THA). Dual mobility components
confer increased stability, but there are concerns about the unique
complications associated with these designs, as well as the long-term
survivorship. We performed a systematic review of all English language articles
dealing with dual mobility THAs published between 2007 and 2016
in the MEDLINE and Embase electronic databases. A total of 54 articles
met inclusion criteria for the final analysis of primary and revision
dual mobility THAs and dual mobility THAs used in the treatment
of fractures of the femoral neck. We analysed the survivorship and
rates of aseptic loosening and of intraprosthetic and extra-articular
dislocation.Aims
Materials and Methods
A variety of operative techniques have been described as under
the term ‘Bristow-Latarjet’ procedure. This review aims to define
the original procedure, and compare the variation in techniques
described in the literature, assessing any effect on clinical outcomes. A systematic review of 24 studies was performed to compare specific
steps of the technique (coracoid osteotomy site, subscapularis approach,
orientation and position of coracoid graft fixation and fixation
method, additional labral and capsular repair) and detect any effect
this variability had on outcomes.Objectives
Materials and Methods
The aim of this study was to investigate the outcomes of Vancouver
type B2 and B3 fractures by performing a systematic review of the
methods of surgical treatment which have been reported. A systematic search was performed in Ovid MEDLINE, Embase and
the Cochrane Central Register of Controlled Trials. For inclusion,
studies required a minimum of ten patients with a Vancouver type
B2 and/or ten patients with a Vancouver type B3 fracture, a minimum
mean follow-up of two years and outcomes which were matched to the type
of fracture. Studies were also required to report the rate of re-operation
as an outcome measure. The protocol was registered in the PROSPERO
database. Aims
Materials and Methods
The primary aim of this study was to define the standard minimum
follow-up required to produce a reliable estimate of the rate of
re-operation after radial head arthroplasty (RHA). The secondary
objective was to define the leading reasons for re-operation. Four electronic databases, between January 2000 and March 2017
were searched. Articles reporting reasons for re-operation (Group
I) and results (Group II) after RHA were included. In Group I, a
meta-analysis was performed to obtain the standard minimum follow-up,
the mean time to re-operation and the reason for failure. In Group
II, the minimum follow-up for each study was compared with the standard
minimum follow-up.Aims
Materials 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:
Reconstruction of the acetabulum after failed total hip arthroplasty
(THA) can be a surgical challenge in the presence of severe bone
loss. We report the long-term survival of a porous tantalum revision
acetabular component, its radiological appearance and quality of
life outcomes. We reviewed the results of 46 patients who had undergone revision
of a failed acetabular component with a Paprosky II or III bone
defect and reconstruction with a hemispherical, tantalum acetabular
component, supplementary screws and a cemented polyethylene liner.Aims
Patients and Methods
Bisphosphonates are widely used as first-line treatment for primary and secondary prevention of fragility fractures. Whilst they have proved effective in this role, there is growing concern over their long-term use, with much evidence linking bisphosphonate-related suppression of bone remodelling to an increased risk of atypical subtrochanteric fractures of the femur (AFFs). The objective of this article is to review this evidence, while presenting the current available strategies for the management of AFFs. We present an evaluation of current literature relating to the pathogenesis and treatment of AFFs in the context of bisphosphonate use.Objectives
Methods
Unicompartmental knee arthroplasty (UKA) is a potential treatment
for isolated bone on bone osteoarthritis when limited to a single
compartment. The risk for revision of UKA is three times higher
than for total knee arthroplasty (TKA). The aim of this review was
to discuss the different revision options after UKA failure. A search was performed for English language articles published
between 2006 and 2016. After reviewing titles and abstracts, 105
papers were selected for further analysis. Of these, 39 papers were
deemed to contain clinically relevant data to be included in this review.Objectives
Materials and Methods
This is a prospective randomised study which compares the radiological
and functional outcomes of ring and rail fixators in patients with
an infected gap (>
3 cm) nonunion of the tibia. Between May 2008 and February 2013, 70 patients were treated
at our Institute for a posttraumatic osseocutaneous defect of the
tibia measuring at least 3 cm. These were randomised into two groups
of 35 patients using the lottery method. Group I patients were treated
with a ring fixator and group II patients with a rail fixator. The
mean age was 33.2 years (18 to 64) in group I and 29.3 years (18
to 65) in group II. The mean bone gap was 5.84 cm in group I and 5.78
cm in group II. The mean followup was 33.8 months in group I and 32.6 months
in group II. Bone and functional results were assessed using the
classification of the Association for the Study and Application
of the Method of Ilizarov (ASAMI). Functional results were also
assessed at six months using the short musculoskeletal functional
assessment (SMFA) score.Aims
Patients and Methods
The aim of this study was to identify risk factors for the failure
of exchange nailing in nonunion of tibial diaphyseal fractures. A cohort of 102 tibial diaphyseal nonunions in 101 patients with
a mean age of 36.9 years (15 to 74) were treated between January
1992 and December 2012 by exchange nailing. Of which 33 (32%) were
initially open injuries. The median time from primary fixation to
exchange nailing was 6.5 months (interquartile range (IQR) 4.3 to
9.8 months). The main outcome measures were union, number of secondary fixation
procedures required to achieve union and time to union. Univariate analysis and multiple regression were used to identify
risk factors for failure to achieve union. Aims
Patients and Methods
An evidence-based radiographic Decision Aid for meniscal-bearing
unicompartmental knee arthroplasty (UKA) has been developed and
this study investigates its performance at an independent centre. Pre-operative radiographs, including stress views, from a consecutive
cohort of 550 knees undergoing arthroplasty (UKA or total knee arthroplasty;
TKA) by a single-surgeon were assessed. Suitability for UKA was
determined using the Decision Aid, with the assessor blinded to
treatment received, and compared with actual treatment received, which
was determined by an experienced UKA surgeon based on history, examination,
radiographic assessment including stress radiographs, and intra-operative
assessment in line with the recommended indications as described
in the literature.Aims
Patients and Methods
Bisphosphonates (BP) are the first-line treatment for preventing fragility fractures. However, concern regarding their efficacy is growing because bisphosphonate is associated with over-suppression of remodelling and accumulation of microcracks. While dual-energy X-ray absorptiometry (DXA) scanning may show a gain in bone density, the impact of this class of drug on mechanical properties remains unclear. We therefore sought to quantify the mechanical strength of bone treated with BP (oral alendronate), and correlate data with the microarchitecture and density of microcracks in comparison with untreated controls. Trabecular bone from hip fracture patients treated with BP (n = 10) was compared with naïve fractured (n = 14) and non-fractured controls (n = 6). Trabecular cores were synchrotron scanned and micro-CT scanned for microstructural analysis, including quantification of bone volume fraction, microarchitecture and microcracks. The specimens were then mechanically tested in compression.Objectives
Methods
Glenoid bone loss can be a challenging problem when revising
a shoulder arthroplasty. Precise pre-operative planning based on
plain radiographs or CT scans is essential. We have investigated
a new radiological classification system to describe the degree
of medialisation of the bony glenoid and that will indicate the
amount of bone potentially available for supporting a glenoid component.
It depends on the relationship between the most medial part of the
articular surface of the glenoid with the base of the coracoid process
and the spinoglenoid notch: it classifies the degree of bone loss
into three types. It also attempts to predict the type of glenoid reconstruction
that may be possible (impaction bone grafting, structural grafting
or simple non-augmented arthroplasty) and gives guidance about whether
a pre-operative CT scan is indicated. Inter-method reliability between plain radiographs and CT scans
was assessed retrospectively by three independent observers using
data from 39 randomly selected patients. Inter-observer reliability and test-retest reliability was tested
on the same cohort using Cohen's kappa statistics. Correlation of
the type of glenoid with the Constant score and its pain component
was analysed using the Kruskal-Wallis method on data from 128 patients.
Anatomical studies of the scapula were reviewed to explain the findings.Aims
Patients 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
Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis.Objectives
Materials and Methods
Intermittently administered parathyroid hormone (PTH 1-34) has been shown to promote bone formation in both human and animal studies. The hormone and its analogues stimulate both bone formation and resorption, and as such at low doses are now in clinical use for the treatment of severe osteoporosis. By varying the duration of exposure, parathyroid hormone can modulate genes leading to increased bone formation within a so-called ‘anabolic window’. The osteogenic mechanisms involved are multiple, affecting the stimulation of osteoprogenitor cells, osteoblasts, osteocytes and the stem cell niche, and ultimately leading to increased osteoblast activation, reduced osteoblast apoptosis, upregulation of Wnt/β-catenin signalling, increased stem cell mobilisation, and mediation of the RANKL/OPG pathway. Ongoing investigation into their effect on bone formation through ‘coupled’ and ‘uncoupled’ mechanisms further underlines the impact of intermittent PTH on both cortical and cancellous bone. Given the principally catabolic actions of continuous PTH, this article reviews the skeletal actions of intermittent PTH 1-34 and the mechanisms underlying its effect.
