According to a report by Millennium Research Group in January 2011, the US orthopaedic extremity device market will generate over $4.6 billion in revenue by 2015.
The June 2013 Shoulder &
Elbow Roundup360 looks at: whether suture anchors are still the gold standard; infection and revision elbow arthroplasty; the variable success of elbow replacements; sliding knots; neurologic cuff pain and the suprascapular nerve; lies, damn lies and statistics; osteoarthritis; and one- or two-stage treatment for the infected shoulder revision.
One commonly used rat fracture model for bone and mineral research
is a closed mid-shaft femur fracture as described by Bonnarens in
1984. Initially, this model was believed to create very reproducible
fractures. However, there have been frequent reports of comminution
and varying rates of complication. Given the importance of precise
anticipation of those characteristics in laboratory research, we
aimed to precisely estimate the rate of comminution, its importance and
its effect on the amount of soft callus created. Furthermore, we
aimed to precisely report the rate of complications such as death
and infection. We tested a rat model of femoral fracture on 84 rats based on
Bonnarens’ original description. We used a proximal approach with
trochanterotomy to insert the pin, a drop tower to create the fracture
and a high-resolution fluoroscopic imager to detect the comminution.
We weighed the soft callus on day seven and compared the soft callus
parameters with the comminution status.Objectives
Methods
The aims of this study were to evaluate the incidence
of local argyria in patients with silver-coated megaprostheses and
to identify a possible association between argyria and elevated
levels of silver both locally and in the blood. Between 2004 and
2011, 32 megaprostheses with silver coatings were implanted in 20
female and 12 male patients following revision arthroplasty for
infection or resection of a malignant tumour, and the levels of
silver locally in drains and seromas and in the blood were determined.
The mean age of the patients was 46 years (10 to 81); one patient
died in the immediate post-operative period and was excluded. Seven patients (23%) developed local argyria after a median of
25.7 months (interquartile range 2 to 44.5). Patients with and without
local argyria had comparable levels of silver in the blood and aspiration
fluids. The length of the implant did not influence the development
of local argyria. Patients with clinical evidence of local argyria
had no neurological symptoms and no evidence of renal or hepatic
failure. Thus, we conclude that the short-term surveillance of blood
silver levels in these patients is not required. Cite this article:
This conversation represents an attempt by several
arthroplasty surgeons to critique several abstracts presented over
the last year as well as to use them as a jumping off point for trying
to figure out where they fit in into our current understanding of
multiple issues in modern hip and knee arthroplasty.
Modern metal-on-metal hip resurfacing has been
widely performed in the United Kingdom for over a decade. However,
the literature reports conflicting views of the benefits: excellent
medium- to long-term results with some brands in specific subgroups,
but high failure rates and local soft-tissue reactions in others.
The National Joint Registry for England and Wales (NJR) has collected
data on all hip resurfacings performed since 2003. This retrospective
cohort study recorded survival time to revision from a resurfacing
procedure, exploring risk factors independently associated with
failure. All patients with a primary diagnosis of osteoarthritis
who underwent resurfacing between 2003 and 2010 were included in
the analyses. Cox’s proportional hazard models were used to analyse
the extent to which the risk of revision was related to patient,
surgeon and implant covariates. A total of 27 971 hip resurfacings were performed during the
study period, of which 1003 (3.59%) underwent revision surgery.
In the final adjusted model, we found that women were at greater
risk of revision than men (hazard ratio (HR) = 1.30, p = 0.007),
but the risk of revision was independent of age. Of the implant-specific
predictors, five brands had a significantly greater risk of revision
than the Birmingham Hip Resurfacing (BHR) (ASR: HR = 2.82, p <
0.001,
Conserve: HR = 2.03, p <
0.001, Cormet: HR = 1.43, p = 0.001,
Durom: HR = 1.67, p <
0.001, Recap: HR = 1.58, p = 0.007). Smaller
femoral head components were also significantly more likely to require
revision (≤ 44 mm: HR = 2.14, p <
0.001, 45 to 47 mm: HR = 1.48,
p = 0.001) than medium or large heads, as were operations performed
by low-volume surgeons (HR = 1.36, p <
0.001). Once these influences
had been removed, in 4873 male patients <
60 years old undergoing
resurfacing with a BHR, the five-year estimated risk of revision
was 1.59%. In summary, after adjustment for a range of covariates we found
that there were significant differences in the rate of failure between
brands and component sizes. Younger male patients had good five-year
implant survival when the BHR was used.
The purpose of this study was twofold: first,
to determine whether the five-year results of hip resurfacing arthroplasty
(HRA) in Canada justified the continued use of HRA; and second,
to identify whether greater refinement of patient selection was
warranted. This was a retrospective cohort study that involved a review
of 2773 HRAs performed between January 2001 and December 2008 at
11 Canadian centres. Cox’s proportional hazards models were used
to analyse the predictors of failure of HRA. Kaplan–Meier survival
analysis was performed to predict the cumulative survival rate at
five years. The factors analysed included age, gender, body mass
index, pre-operative hip pathology, surgeon’s experience, surgical
approach, implant sizes and implant types. The most common modes
of failure were also analysed. The 2773 HRAs were undertaken in 2450 patients: 2127 in men and
646 in women. The mean age at operation was 50.5 years ( The failure rates of HRA at five years justify the ongoing use
of this technique in men. Female gender is an independent predictor
of failure, and a higher failure rate at five years in women leads
the authors to recommend this technique only in exceptional circumstances
for women. Cite this article:
The aim of this study was to review the early
outcome of the Femoro-Patella Vialla (FPV) joint replacement. A
total of 48 consecutive FPVs were implanted between December 2007
and June 2011. Case-note analysis was performed to evaluate the
indications, operative histology, operative findings, post-operative
complications and reasons for revision. The mean age of the patients
was 63.3 years (48.2 to 81.0) and the mean follow-up was
25.0 months (6.1 to 48.9). Revision was performed in seven (14.6%)
at a mean of 21.7 months, and there was one re-revision. Persistent
pain was observed in three further patients who remain unrevised.
The reasons for revision were pain due to progressive tibiofemoral
disease in five, inflammatory arthritis in one, and patellar fracture following
trauma in one. No failures were related to the implant or the technique.
Trochlear dysplasia was associated with a significantly lower rate
of revision (5.9% Focal patellofemoral osteoarthritis secondary to trochlear dysplasia
should be considered the best indication for patellofemoral replacement.
Standardised radiological imaging, with MRI to exclude overt tibiofemoral
disease should be part of the pre-operative assessment, especially
for the non-dysplastic knee. Cite this article:
The Manchester–Oxford Foot Questionnaire (MOXFQ) is a validated
16-item, patient-reported outcome measure for evaluating outcomes
of foot or ankle surgery. The original development of the instrument
identified three domains. This present study examined whether the
three domains could legitimately be summed to provide a single summary
index score. The MOXFQ and Short-Form (SF)-36 were administered to 671 patients
before surgery of the foot or ankle. Data from the three domains
of the MOXFQ (pain, walking/standing and social interaction) were
subjected to higher order factor analysis. Reliability and validity
of the summary index score was assessed.Objectives
Methods
A new generation of knee prostheses has been introduced with the intention of improving post-operative knee flexion. In order to evaluate whether this goal has been achieved we performed a systematic review and meta-analysis. Systematic literature searches were conducted on MEDLINE and EMBASE from their inception to December 2007, and proceedings of scientific meetings were also searched. Only randomised, clinical trials were included in the meta-analysis. The mean difference in the maximum post-operative flexion between the ‘high-flex’ and conventional types of prosthesis was defined as the primary outcome measure. A total of five relevant articles was identified. Analysis of these trials suggested that no clinically relevant or statistically significant improvement was obtained in flexion with the ‘high-flex’ prostheses. The weighted mean difference was 2.1° (95% confidence interval −0.2 to +4.3; p = 0.07).
In Canada, Dupuytren's contracture is managed
with partial fasciectomy or percutaneous needle aponeurotomy (PNA).
Injectable collagenase will soon be available. The optimal management
of Dupuytren’s contracture is controversial and trade-offs exist
between the different methods. Using a cost-utility analysis approach,
our aim was to identify the most cost-effective form of treatment
for managing Dupuytren’s contracture it and the threshold at which
collagenase is cost-effective. We developed an expected-value decision
analysis model for Dupuytren’s contracture affecting a single finger,
comparing the cost-effectiveness of fasciectomy, aponeurotomy and collagenase
from a societal perspective. Cost-effectiveness, one-way sensitivity
and variability analyses were performed using standard thresholds
for cost effective treatment ($50 000 to $100 000/QALY gained).
Percutaneous needle aponeurotomy was the preferred strategy for
managing contractures affecting a single finger. The cost-effectiveness
of primary aponeurotomy improved when repeated to treat recurrence.
Fasciectomy was not cost-effective. Collagenase was cost-effective
relative to and preferred over aponeurotomy at $875 and $470 per
course of treatment, respectively. In summary, our model supports the trend towards non-surgical
interventions for managing Dupuytren’s contracture affecting a single
finger. Injectable collagenase will only be feasible in our publicly
funded healthcare system if it costs significantly less than current
United States pricing. Cite this article:
We have recently shown that waste heat from forced-air
warming blankets can increase the temperature and concentration
of airborne particles over the surgical site. The mechanism for
the increased concentration of particles and their site of origin
remained unclear. We therefore attempted to visualise the airflow
in theatre over a simulated total knee replacement using neutral-buoyancy
helium bubbles. Particles were created using a Rocket PS23 smoke
machine positioned below the operating table, a potential area of
contamination. The same theatre set-up, warming devices and controls
were used as in our previous study. This demonstrated that waste
heat from the poorly insulated forced-air warming blanket increased
the air temperature on the surgical side of the drape by >
5°C.
This created convection currents that rose against the downward
unidirectional airflow, causing turbulence over the patient. The
convection currents increased the particle concentration 1000-fold
(2 174 000 particles/m3 for forced-air warming Cite this article:
The April 2013 Hip &
Pelvis Roundup360 looks at: hip cartilage and magnets; labral repair or resection; who benefits from injection; rotational osteotomy for osteonecrosis; whether ceramic implants risk fracture; dual articulation; and hydroxyapatite.
The April 2013 Research Roundup360 looks at: when the ‘residency cake’ is done; steroids, stem cells and tendons; what exactly is osteoarthritis; platelet-rich plasma; CRPS; d-Dimer for DVT; reducing bacterial adhesion; and fin or limb?
To report the five-year results of a randomised controlled trial
examining the effectiveness of arthroscopic acromioplasty in the
treatment of stage II shoulder impingement syndrome. A total of 140 patients were randomly divided into two groups:
1) supervised exercise programme (n = 70, exercise group); and 2)
arthroscopic acromioplasty followed by a similar exercise programme
(n = 70, combined treatment group).Objectives
Methods
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: