The Oxford hip score (OHS) is a 12-item questionnaire designed
and developed to assess function and pain from the perspective of
patients who are undergoing total hip replacement (THR). The OHS
has been shown to be consistent, reliable, valid and sensitive to
clinical change following THR. It has been translated into different
languages, but no adequately translated, adapted and validated Danish
language version exists. The OHS was translated and cross-culturally adapted into Danish
from the original English version, using methods based on best-practice
guidelines. The translation was tested for psychometric quality
in patients drawn from a cohort from the Danish Hip Arthroplasty
Register (DHR).Objectives
Methods
The aim of this study was to define the incidence
of venous thromboembolism (VTE) and risk factors for the development
of deep-vein thrombosis (DVT) after the resection of a musculoskeletal
tumour. A total of 94 patients who underwent resection of a musculoskeletal
tumour between January 2003 and December 2005 were prospectively
studied. There were 42 men and 52 women with a mean age of 54.4
years (18 to 86). All patients wore intermittent pneumatic compression
devices and graduated compression stockings. Ultrasound examination
of the lower limbs was conducted to screen for DVT between the fifth
and ninth post-operative days. DVT was detected in 21 patients (22%). Of these, two were symptomatic
(2%). One patient (1%) had a fatal pulmonary embolism. Patients
aged ≥ 70 years had an increased risk of DVT (p = 0.004). The overall incidence of DVT (both symptomatic and asymptomatic)
after resection of a musculoskeletal tumour with mechanical prophylaxis
was high. It seems that both mechanical and anticoagulant prophylaxis
is needed to prevent VTE in patients who have undergone the resection
of a musculoskeletal tumour. Cite this article:
Despite the worldwide usage of the cemented Contemporary
acetabular component (Stryker), no published data are available
regarding its use in patients aged <
50 years. We undertook a
mid- to long-term follow-up study, including all consecutive patients
aged
<
50 years who underwent a primary total hip replacement using
the Contemporary acetabular component with the Exeter cemented stem
between January 1999 and January 2006. There were 152 hips in 126
patients, 61 men and 65 women, mean age at surgery 37.6 years (16
to 49 yrs). One patient was lost to follow-up. Mean clinical follow-up of all implants was 7.6 years (0.9 to
12.0). All clinical questionnaire scores, including Harris hip score,
Oxford hip score and several visual analogue scales, were found
to have improved. The eight year survivorship of all acetabular
components for the endpoints revision for any reason or revision
for aseptic loosening was 94.4% (95% confidence interval (CI) 89.2
to 97.2) and 96.4% (95% CI 91.6 to 98.5), respectively. Radiological follow-up
was complete for 146 implants. The eight year survival for the endpoint
radiological loosening was 93.1% (95% CI 86.2 to 96.6). Three surviving
implants were considered radiologically loose but were asymptomatic.
The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent
lines (n = 20, 13.9%) in the 144 surviving cups indicates a need
for continued observation in the second decade of follow-up in order
to observe their influence on long-term survival. The clinical and radiological data resulting in a ten-year survival
rate >
90% in young patients support the use of the Contemporary
acetabular component in this specific patient group. Cite this article:
Pseudotumours (abnormal peri-prosthetic soft-tissue reactions)
following metal-on-metal hip resurfacing arthroplasty (MoMHRA) have
been associated with elevated metal ion levels, suggesting that
excessive wear may occur due to edge-loading of these MoM implants.
This study aimed to quantify The duration and magnitude of edge-loading Objectives
Methods
We retrospectively analysed concentrations of chromium and cobalt ions in samples of synovial fluid and whole blood taken from a group of 92 patients with failed current-generation metal-on-metal hip replacements. We applied acid oxidative digestion to our trace metal analysis protocol, which found significantly higher levels of metal ion concentrations in blood and synovial fluid than a non-digestive method. Patients were subcategorised by mode of failure as either ‘unexplained pain’ or ‘defined causes’. Using this classification, chromium and cobalt ion levels were present over a wider range in synovial fluid and not as strongly correlated with blood ion levels as previously reported. There was no significant difference between metal ion concentrations and manufacturer of the implant, nor femoral head size below or above 50 mm. There was a moderately positive correlation between metal ion levels and acetabular component inclination angle as measured on three-dimensional CT imaging. Our results suggest that acid digestion of samples of synovial fluid samples is necessary to determine metal ion concentrations accurately so that meaningful comparisons can be made between studies.
A total of 397 hips were randomised to receive
Metasul metal-on-metal (MoM), metal-on-conventional polyethylene (MoP)
or ceramic-on-polyethylene (CoP) bearings using a cemented triple-tapered
polished femoral component (MS-30). There were 129 MoM hips in 123
patients (39 male and 84 female, mean age 63.3 years (40.7 to 72.9)),
137 MoP hips in 127 patients (39 male and 88 female, mean age 62.8
years (24.5 to 72.7)) and 131 CoP hips in 124 patients (51 male
and 73 female, mean age 63.9 years (30.6 to 73.8)). All acetabular
components were cemented Weber polyethylene components with the
appropriate inlay for the MoM articulation. Clinical evaluation
was undertaken using the Harris hip score (HHS) and radiological
assessments were made at two, five and seven years. The HHS and radiological
analysis were available for 341 hips after seven years. The MoM
group had the lowest mean HHS (p = 0.124), a higher rate of revision
(p <
0.001) and a higher incidence of radiolucent lines in unrevised
hips (p <
0.001). In all, 12 revisions had been performed in
12 patients: eight in the MoM group (four for infection, four for
aseptic loosening, three in the MoP group (one each of infection,
dislocation and pain) and one in the CoP group (infection). Our findings reveal no advantage to the MoM bearing and identified
a higher revision rate and a greater incidence of radiolucent lines
than with the other articulations. We recommend that patients with
a 28 mm Metasul MoM bearing be followed carefully. Cite this article:
We have developed a novel method of calculating the radiological magnification of the hip using two separate radio-opaque markers. We recruited 74 patients undergoing radiological assessment following total hip replacement. Both the new double marker and a conventional single marker were used by the radiographer at the time of x-ray. The predicted magnification according to each marker was calculated, as was the true radiological magnification of the components. The correlation between true and predicted magnification was good using the double marker (r = 0.90, n = 74, p <
0.001), but only moderate for the single marker (r = 0.50, n = 63, p <
0.001). The median error was significantly less for the double marker than for the single (1.1% The double marker method appears to be superior to the single marker method when used in the clinical environment.
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.
This study compared component wear rates and pre-revision blood metal ions levels in two groups of failed metal-on-metal hip arthroplasties: hip resurfacing and modular total hip replacement (THR). There was no significant difference in the median rate of linear wear between the groups for both acetabular (p = 0.4633) and femoral (p = 0.0872) components. There was also no significant difference in the median linear wear rates when failed hip resurfacing and modular THR hips of the same type (ASR and Birmingham hip resurfacing (BHR)) were compared. Unlike other studies of well-functioning hips, there was no significant difference in pre-revision blood metal ion levels between hip resurfacing and modular THR. Edge loading was common in both groups, but more common in the resurfacing group (67%) than in the modular group (57%). However, this was not significant (p = 0.3479). We attribute this difference to retention of the neck in resurfacing of the hip, leading to impingement-type edge loading. This was supported by visual evidence of impingement on the femur. These findings show that failed metal-on-metal hip resurfacing and modular THRs have similar component wear rates and are both associated with raised pre-revision blood levels of metal ions.
We have studied the relationship between metal ion levels and lymphocyte counts in patients with metal-on-metal hip resurfacings. Peripheral blood samples were analysed for lymphocyte subtypes and whole blood cobalt and chromium ion levels in 68 patients (34 with metal-on-metal hip resurfacings and 34 with standard metal-on-polyethylene total hip replacements). All hip components were radiologically well-fixed and the patients were asymptomatic. Cobalt and chromium levels were significantly elevated in the patients with metal-on-metal hip resurfacings, compared with the patients with standard metal-on-polyethylene designs (p <
0.0001). There was a statistically significant decrease in the level of CD8+ cells (T-cytotoxic/suppressor) (p = 0.005) in the metal-on-metal hip resurfacing group. A threshold level of blood cobalt and chromium ions was associated with reduced CD8+ T-cell counts. We have no evidence that our patients suffered as a result of this reduced level of CD8+ T-cells.
The June 2013 Children’s orthopaedics Roundup360 looks at: whether reaching a diagnosis is more difficult than previously thought; adolescent and paediatric DDH; the A-frame orthosis and Legg-Calvé-Perthes’ disease; failure of hip surgery in patients with cerebral palsy; adolescent rotator cuff injuries; paediatric peripheral nerve injuries; predicting residual deformity following Ponseti treatment; and the Dunn procedure.
Guidelines for the management of patients with metastatic bone
disease (MBD) have been available to the orthopaedic community for
more than a decade, with little improvement in service provision
to this increasingly large patient group. Improvements in adjuvant
and neo-adjuvant treatments have increased both the number and overall
survival of patients living with MBD. As a consequence the incidence
of complications of MBD presenting to surgeons has increased and
is set to increase further. The British Orthopaedic Oncology Society
(BOOS) are to publish more revised detailed guidelines on what represents
‘best practice’ in managing patients with MBD. This article is designed
to coincide with and publicise new BOOS guidelines and once again
champion the cause of patients with MBD. A series of short cases highlight common errors frequently being
made in managing patients with MBD despite the availability of guidelines.Objectives
Methods
We report serum metal ion level data in patients with unilateral and bilateral hip resurfacing over a ten-year period. In these patients there is an increase in both cobalt and chromium levels above the accepted reference ranges during the first 18 months after operation. Metal ion levels remain elevated, but decline slowly for up to five years. However, the levels then appear to start rising again in some patients up to the ten-year mark. There was no significant difference in cobalt or chromium levels between men and women. These findings appear to differ from much of the current literature. The clinical significance of a raised metal ion level remains under investigation.
We reviewed the initial post-operative radiographs of the Trident acetabulum and identified a problem with seating of the metal-backed ceramic liner. We identified 117 hips in 113 patients who had undergone primary total hip replacement using the Trident shell with a metal-backed alumina liner. Of these, 19 (16.4%) were noted to have incomplete seating of the liner, as judged by plain anteroposterior and lateral radiographs. One case of complete liner dissociation necessitating early revision was not included in the prevalence figures. One mis-seated liner was revised in the early post-operative period and two that were initially incompletely seated were found on follow-up radiographs to have become correctly seated. There may be technical issues with regard to the implanting of this prosthesis of which surgeons should be aware. However, there is the distinct possibility that the Trident shell deforms upon implantation, thereby preventing complete seating of the liner.
This year is the centenary of the birth of John Charnley. Some of his legacy to Orthopaedic Surgery is described in this editorial.
The aim of this study was to investigate the
possible benefit of large-head metal-on-metal bearing on a stem
for primary hip replacement compared with a 28 mm diameter conventional
metal-on-polyethylene bearing in a prospective randomised controlled
trial. We investigated cemented stem behaviour between these two
different bearings using Einzel-Bild-Röntgen-Analyse, clinical and
patient reported measures (Harris hip score, Western Ontario and
McMaster Universities osteoarthritis index, Short Form-36 and satisfaction)
and whole blood metal ion levels at two years. A power study indicated
that 50 hips were needed in each group to detect subsidence of >
5 mm at two years with a
p-value of <
0.05. Significant improvement (p <
0.001) was found in the mean
clinical and patient reported outcomes at two years for both groups.
Comparison of outcomes between the groups at two years showed no
statistically significant difference for mean stem migration, clinical
and patient reported outcomes; except overall patient satisfaction which
was higher for metal-on-metal group (p = 0.05). Metal ion levels
were raised above the Medicines and Healthcare products Regulatory
Agency advised safety level (7 µg per litre) in 20% of the metal-on-metal
group and in one patient in metal-on-polyethylene group (who had
a metal-on-metal implant on the contralateral side). Two patients
in the metal-on-metal group were revised, one for pseudotumour and
one for peri-prosthetic fracture. Use of large modular heads is associated with a risk of raised
whole blood metal ion levels despite using a proven bearing from
resurfacing. The head-neck junction or excess stem micromotion are
possibly the weak links warranting further research.
The design of the Charnley total hip replacement follows the principle of low frictional torque. It is based on the largest possible difference between the radius of the femoral head and that of the outer aspect of the acetabular component. The aim is to protect the bone-cement interface by movement taking place at the smaller radius, the articulation. This is achieved in clinical practice by a 22.225 mm diameter head articulating with a 40 mm or 43 mm diameter acetabular component of ultra-high molecular weight polyethylene. We compared the incidence of aseptic loosening of acetabular components with an outer diameter of 40 mm and 43 mm at comparable depths of penetration with a mean follow-up of 17 years (1 to 40). In cases with no measurable wear none of the acetabular components were loose. With increasing acetabular penetration there was an increased incidence of aseptic loosening which reflected the difference in the external radii, with 1.5% at 1 mm, 8.8% at 2 mm, 9.7% at 3 mm and 9.6% at 4 mm of penetration in favour of the larger 43 mm acetabular component. Our findings support the Charnley principle of low frictional torque. The level of the benefit is in keeping with the predicted values.
We have analysed from the Finnish Arthroplasty Register the long-term survivorship of the 12 most commonly-used cemented implants between 1980 and 2005 in patients aged 55 years or older with osteoarthritis. Only two designs of femoral component, the Exeter Universal and the Müller Straight femoral component had a survivorship of over 95% at ten years with revision for aseptic loosening as the endpoint. At 15 years of the femoral and acetabular component combinations, only the Exeter Universal/Exeter All-poly implant had a survival rate of over 90% with revision for aseptic loosening as the endpoint. In the subgroup of patients aged between 55 and 64 years, survivorship overall was less than 90% at ten years. The variation in the long-term rates of survival of different cemented hip implants was considerable in patients aged 55 years or older. In those aged between 55 and 64 years, none of the cemented prostheses studied yielded excellent long-term survival rates (≥ 90% at 15 years).
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.
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: