The aim of this study was to evaluate the incidence of liner malseating in two commonly used dual-mobility (DM) designs. Secondary aims included determining the risk of dislocation, survival, and clinical outcomes. We retrospectively identified 256 primary total hip arthroplasties (THAs) that included a DM component (144 Stryker MDM and 112 Zimmer-Biomet G7) in 233 patients, performed between January 2012 and December 2019. Postoperative radiographs were reviewed independently for malseating of the liner by five reviewers. The mean age of the patients at the time of THA was 66 years (18 to 93), 166 (65%) were female, and the mean BMI was 30 kg/m2 (17 to 57). The mean follow-up was 3.5 years (2.0 to 9.2).Aims
Methods
There is evidence that morbidly obese patients have more intra- and postoperative complications and poorer outcomes when undergoing total hip arthroplasty (THA) with the direct anterior approach (DAA). The aim of this study was to determine the efficacy of DAA for THA, and compare the complications and outcomes of morbidly obese patients with nonobese patients. Morbidly obese patients (n = 86), with BMI ≥ 40 kg/m2 who underwent DAA THA at our institution between September 2010 and December 2017, were matched to 172 patients with BMI < 30 kg/m2. Data regarding demographics, set-up and operating time, blood loss, radiological assessment, Harris Hip Score (HHS), International Hip Outcome Tool (12-items), reoperation rate, and complications at two years postoperatively were retrospectively analyzed.Aims
Methods
To develop and externally validate a parsimonious statistical prediction model of 90-day mortality after elective total hip arthroplasty (THA), and to provide a web calculator for clinical usage. We included 53,099 patients with cemented THA due to osteoarthritis from the Swedish Hip Arthroplasty Registry for model derivation and internal validation, as well as 125,428 patients from England and Wales recorded in the National Joint Register for England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey (NJR) for external model validation. A model was developed using a bootstrap ranking procedure with a least absolute shrinkage and selection operator (LASSO) logistic regression model combined with piecewise linear regression. Discriminative ability was evaluated by the area under the receiver operating characteristic curve (AUC). Calibration belt plots were used to assess model calibration.Aims
Methods
The gluteus minimus (GMin) and gluteus medius (GMed) have unique structural and functional segments that may be affected to varying degrees, by end-stage osteoarthritis (OA) and normal ageing. We used data from patients with end-stage OA and matched healthy controls to 1) quantify the atrophy of the GMin and GMed in the two groups and 2) describe the distinct patterns of the fatty infiltration in the different segments of the GMin and GMed in the two groups. A total of 39 patients with end-stage OA and 12 age- and sex frequency-matched healthy controls were prospectively enrolled in the study. Fatty infiltration within the different segments of the GMin and the GMed was assessed on MRI according to the semiquantitative classification system of Goutallier and normalized cross-sectional areas were measured.Aims
Methods
Our aim was to examine the Elixhauser and Charlson comorbidity indices, based on administrative data available before surgery, and to establish their predictive value for mortality for patients who underwent hip arthroplasty in the management of a femoral neck fracture. We analyzed data from 42 354 patients from the Swedish Hip Arthroplasty Register between 2005 and 2012. Only the first operated hip was included for patients with bilateral arthroplasty. We obtained comorbidity data by linkage from the Swedish National Patient Register, as well as death dates from the national population register. We used univariable Cox regression models to predict mortality based on the comorbidity indices, as well as multivariable regression with age and gender. Predictive power was evaluated by a concordance index, ranging from 0.5 to 1 (with the higher value being the better predictive power). A concordance index less than 0.7 was considered poor. We used bootstrapping for internal validation of the results.Aims
Patients and Methods
The primary aim of this study was to quantify the improvement in patient-reported outcome measures (PROMs) following total hip arthroplasty (THA), as well as the extent of any deterioration through the seven-year follow-up. The secondary aim was to identify predictors of PROM improvement and deterioration. A total of 976 patients were enrolled into a prospective, international, multicentre study. Patients completed a battery of PROMs prior to THA, at three months post-THA, and at one, three, five, and seven-years post-THA. The Harris Hip Score (HHS), the 36-Item Short-Form Health Survey (SF-36) Physical Component Summary (PCS), the SF-36 Mental Component Summary (MCS), and the EuroQol five-dimension three-level (EQ-5D) index were the primary outcomes. Longitudinal changes in each PROM were investigated by piece-wise linear mixed effects models. Clinically significant deterioration was defined for each patient as a decrease of one half of a standard deviation (group baseline).Aims
Patients and Methods
Many case reports and small studies have suggested that cobalt
ions are a potential cause of cardiac complications, specifically
cardiomyopathy, after metal-on-metal (MoM) total hip arthroplasty
(THA). The impact of metal ions on the incidence of cardiac disease
after MoM THA has not been evaluated in large studies. The aim of
this study was to compare the rate of onset of new cardiac symptoms
in patients who have undergone MoM THA with those who have undergone
metal-on-polyethylene (MoP) THA. Data were extracted from the Standard Analytics Files database
for patients who underwent MoM THA between 2005 and 2012. Bearing
surface was selected using International Classification of Diseases
ninth revision codes. Patients with a minimum five-year follow-up
were selected. An age and gender-matched cohort of patients who underwent
MoP THA served as a comparison group. New diagnoses of cardiac disease
were collected during the follow-up period. Comorbidities and demographics
were identified and routine descriptive statistics were used.Aims
Patients and Methods
We compared the outcome of total hip arthroplasty (THA) in obese
patients who previously underwent bariatric surgery and those who
did not, in a matched cohort study. There were 47 THAs in the bariatric group (42 patients), and
94 THAs in the comparison group (92 patients). The mean age of the
patients was 57 years in both groups (24 to 79) and 57% of the patients
in both groups were women. The mean time between bariatric surgery
and THA was five years (four months to 12 years) in the bariatric group.
The mean follow-up after THA was three years (2 to 9). Aims
Patients and Methods
As adverse events related to metal on metal hip
arthroplasty have been better understood, there has been increased
interest in toxicity related to the high circulating levels of cobalt ions.
However, distinguishing true toxicity from benign elevations in
cobalt levels can be challenging. The purpose of this review is
to examine the use of cobalt alloys in total hip arthroplasty, to
review the methods of measuring circulating cobalt levels, to define
a level of cobalt which is considered pathological and to review
the pathophysiology, risk factors and treatment of cobalt toxicity.
To the best of our knowledge, there are 18 published cases where
cobalt metal ion toxicity has been attributed to the use of cobalt-chromium
alloys in hip arthroplasty. Of these cases, the great majority reported
systemic toxic reactions at serum cobalt levels more than 100 μg/L.
This review highlights some of the clinical features of cobalt toxicity,
with the goal that early awareness may decrease the risk factors
for the development of cobalt toxicity and/or reduce its severity. Take home message: Severe adverse events can arise from the release
of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic
surgeons should not only be aware of the presenting problems, but
also have the knowledge to treat appropriately. Cite this article:
The early failure and revision of bimodular primary
total hip arthroplasty prostheses requires the identification of the
risk factors for material loss and wear at the taper junctions through
taper wear analysis. Deviations in taper geometries between revised
and pristine modular neck tapers were determined using high resolution
tactile measurements. A new algorithm was developed and validated
to allow the quantitative analysis of material loss, complementing
the standard visual inspection currently used. The algorithm was applied to a sample of 27 retrievals ( Cite this article:
The purpose of this study was to examine the
complications and outcomes of total hip replacement (THR) in super-obese
patients (body mass index (BMI) >
50 kg/m2) compared
with class I obese (BMI 30 to 34.9 kg/m2) and normal-weight
patients (BMI 18.5 to 24.9 kg/m2), as defined by the
World Health Organization. A total of 39 THRs were performed in 30 super-obese patients
with a mean age of 53 years (31 to 72), who were followed for a
mean of 4.2 years (2.0 to 11.7). This group was matched with two
cohorts of normal-weight and class I obese patients, each comprising
39 THRs in 39 patients. Statistical analysis was performed to determine differences
among these groups with respect to complications and satisfaction
based on the Western Ontario and McMaster Universities (WOMAC) osteoarthritis
index, the Harris hip score (HHS) and the Short-Form (SF)-12 questionnaire. Super-obese patients experienced significantly longer hospital
stays and higher rates of major complications and readmissions than
normal-weight and class I obese patients. Although super-obese patients
demonstrated reduced pre-operative and post-operative satisfaction
scores, there was no significant difference in improvement, or change in
the score, with respect to HHS or the WOMAC osteoarthritis index. Super-obese patients obtain similar satisfaction outcomes as
class I obese and normal-weight patients with respect to improvement
in their scores. However, they experience a significant increase
in length of hospital stay and major complication and readmission
rates. Cite this article:
Symptomatic cobalt toxicity from a failed total
hip replacement is a rare but devastating complication. It has been reported
following revision of fractured ceramic components, as well as in
patients with failed metal-on-metal articulations. Potential clinical
findings include fatigue, weakness, hypothyroidism, cardiomyopathy,
polycythaemia, visual and hearing impairment, cognitive dysfunction,
and neuropathy. We report a case of an otherwise healthy 46-year-old
patient, who developed progressively worsening symptoms of cobalt
toxicity beginning approximately six months following synovectomy
and revision of a fractured ceramic-on-ceramic total hip replacement
to a metal-on-polyethylene bearing. The whole blood cobalt levels
peaked at 6521 µg/l. The patient died from cobalt-induced cardiomyopathy.
Implant retrieval analysis confirmed a loss of 28.3 g mass of the
cobalt–chromium femoral head as a result of severe abrasive wear
by ceramic particles embedded in the revision polyethylene liner.
Autopsy findings were consistent with heavy metal-induced cardiomyopathy. We recommend using new ceramics at revision to minimise the risk
of wear-related cobalt toxicity following breakage of ceramic components. Cite this article:
The outcome after total hip replacement has improved
with the development of surgical techniques, better pain management
and the introduction of enhanced recovery pathways. These pathways
require a multidisciplinary team to manage pre-operative education,
multimodal pain control and accelerated rehabilitation. The current economic
climate and restricted budgets favour brief hospitalisation while
minimising costs. This has put considerable pressure on hospitals
to combine excellent results, early functional recovery and shorter
admissions. In this review we present an evidence-based summary of some common
interventions and methods, including pre-operative patient education,
pre-emptive analgesia, local infiltration analgesia, pre-operative
nutrition, the use of pulsed electromagnetic fields, peri-operative
rehabilitation, wound dressings, different surgical techniques, minimally
invasive surgery and fast-track joint replacement units. Cite this article:
To investigate psychosocial and biomedical outcomes following
total hip replacement (THR) and to identify predictors of recovery
from THR. Patients with osteoarthritis (OA) on the waiting list for primary
THR in North West England were assessed pre-operatively and at six
and 12 months post-operatively to investigate psychosocial and biomedical
outcomes. Psychosocial outcomes were anxiety and depression, social
support and health-related quality of life (HRQoL). Biomedical outcomes
were pain, physical function and stiffness. The primary outcome
was the Short-Form 36 (SF-36) Health Survey Total Physical Function.
Potential predictors of outcome were age, sex, body mass index,
previous joint replacement, involvement in the decision for THR,
any comorbidities, any complications, type of medication, and pre-operative
ENRICHD Social Support Instrument score, Hospital Anxiety and Depression
scores and Western Ontario and McMaster Universities osteoarthritis index
score.Objectives
Methods
While an increasing amount of arthroplasty articles
report comorbidity measures, none have been validated for outcomes.
In this study, we compared commonly used International Classification
of Diseases-based comorbidity measures with re-operation rates after
total hip replacement (THR). Scores used included the Charlson,
the Royal College of Surgeons Charlson, and the Elixhauser comorbidity
score. We identified a nationwide cohort of 134 423 THRs from the
Swedish Hip Arthroplasty Register. Re-operations were registered
post-operatively for up to 12 years. The hazard ratio was estimated
by Cox’s proportional hazards regression, and we used C-statistics
to assess each measure’s ability to predict re-operation. Confounding
variables were age, gender, type of implant fixation, hospital category,
hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant
relationship with increased risk of re-operation, with increased
scores for both one to two and three or more comorbidities. However,
the predictive C-statistic in this period for the Elixhauser score
was poor (0.52). None of the measures proved to be of any value between
two and 12 years. They might be of value in large cohort or registry
studies, but not for the individual patient. Cite this article:
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:
Fracture of a ceramic component in total hip
replacement is a rare but potentially catastrophic complication.
The incidence is likely to increase as the use of ceramics becomes
more widespread. We describe such a case, which illustrates how
inadequate initial management will lead to further morbidity and
require additional surgery. We present the case as a warning that
fracture of a ceramic component should be revised to another ceramic-on-ceramic
articulation in order to minimise the risk of further catastrophic
wear.
We compared 55 consecutive total hip replacements performed on 53 morbidly obese patients with osteoarthritis with a matched group of 55 total hip replacements in 53 non-obese patients. The groups were matched for age, gender, prosthesis type, laterality and preoperative Harris Hip Score. They were followed prospectively for five years and the outcomes were assessed using the Harris Hip Score, the Short-form 36 score and radiological findings. Survival at five years using revision surgery as an endpoint, was 90.9% (95% confidence interval 82.9 to 98.9) for the morbidly obese and 100% for the non-obese patients. The Harris Hip and the Short-form 36 scores were significantly better in the non-obese group (p <
0.001). The morbidly obese patients had a higher rate of complications (22% In light of these inferior results, morbidly obese patients should be advised to lose weight before undergoing a total hip replacement, and counselled regarding the complications. Despite these poorer results, however, the patients have improved function and quality of life.
We describe three cases of fracture of the titanium JRI-Furlong hydroxyapatite-ceramic (HAC)-coated femoral component. We have examined previous case reports of failure of this stem and conclude that fracture may occur in two places, namely at the neck-shoulder junction and at the conical-distal cylindrical junction. These breakages are the result of fatigue in a metallurgically-proven normal femoral component. All the cases of failure of the femoral component have occurred in patients with a body mass index of more than 25 in whom a small component, either size 9 or 10, had been used. In patients with a body mass index above normal size 9 components should be avoided and the femoral canal should be reamed sufficiently to accept a large femoral component to ensure that there is adequate metaphyseal fixation.
