The use of short stems has become more popular
with the increased interest in less invasive approaches for total hip
arthroplasty. The curved broaches and stem can be inserted along
a curved track to avoid the abductor attachments. Short stems have
the potential of being more bone conserving by allowing for higher
neck retention, maintenance of the medial greater trochanter, and
preferential stress transfer to the proximal femur. An initial experience with 500 new short stems (Fitmore, Zimmer
Orthopedics) stems used for total hip arthroplasty is reported.
No stems have been revised for aseptic loosening.
We report the long-term survival and functional
outcome of the Birmingham Hip Resurfacing (BHR) in patients aged <
50 years at operation, and explore the factors affecting survival.
Between 1997 and 2006, a total of 447 BHRs were implanted in 393
patients (mean age 41.5 years (14.9 to 49.9)) by one designing surgeon.
The mean follow-up was 10.1 years (5.2 to 14.7), with no loss to
follow-up. In all, 16 hips (3.6%) in 15 patients were revised, giving
an overall cumulative survival of 96.3% (95% confidence interval
(CI) 93.7 to 98.3) at ten years and 94.1% (95% CI 84.9 to 97.3)
at 14 years. Using aseptic revision as the endpoint, the survival
for men with primary osteoarthritis (n = 195) was 100% (95% CI 100
to 100) at both ten years and 14 years, and in women with primary
osteoarthritis (n = 109) it was 96.1% (95% CI 90.1 to 99.9) at ten
years and 91.2% (95% CI 68.6 to 98.7) at 14 years. Female gender
(p = 0.047) and decreasing femoral head size (p = 0.044) were significantly
associated with an increased risk of revision. The median Oxford
hip score (OHS, modified as a percentage with 100% indicating worst
outcome) at last follow-up was 4.2% (46 of 48; interquartile range
(IQR) 0% to 24%) and the median University of California, Los Angeles
(UCLA) score was 6.0 (IQR 5 to 8). Men had significantly better
OHS (p = 0.02) and UCLA scores (p = 0.01) than women. The BHR provides
excellent survival and functional results in men into the second
decade, with good results achieved in appropriately selected women. Cite this article:
Version of the femoral stem is an important factor
influencing the risk of dislocation after total hip replacement (THR)
as well as the position of the acetabular component. However, there
is no radiological method of measuring stem anteversion described
in the literature. We propose a radiological method to measure stem
version and have assessed its reliability and validity. In 36 patients
who underwent THR, a hip radiograph and CT scan were taken to measure
stem anteversion. The radiograph was a modified Budin view. This
is taken as a posteroanterior radiograph in the sitting position
with 90° hip flexion and 90° knee flexion and 30° hip abduction.
The angle between the stem-neck axis and the posterior intercondylar
line was measured by three independent examiners. The intra- and
interobserver reliabilities of each measurement were examined. The
radiological measurements were compared with the CT measurements
to evaluate their validity. The mean radiological measurement was
13.36° ( Cite this article:
The October 2012 Research Roundup360 looks at: whether you can escape your genes; oral prophylaxis for DVT; non-responders and the internet; metal-on-metal, mice and damaged livers; sleeping on the job; cartilage contact stress in the normal human hip; and a perfect reason to subscribe to
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:
An 81-year-old woman presented with a fracture
in the left femur. She had well-fixed bilateral hip replacements
and had received long-term bisphosphonate treatment. Prolonged bisphosphonate
use has been recently linked with atypical subtrochanteric and diaphyseal
femoral fractures. While the current definition of an atypical fracture
of the femur excludes peri-prosthetic fractures, this case suggests
that they do occur and should be considered in patients with severe
osteopenia. Union of the fracture followed cessation of bisphosphonates
and treatment with teriparatide. Thus, this case calls into question
whether prophylactic intramedullary nailing is sufficient alone
to treat early or completed atypical femoral fractures.
The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation. Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry. We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.
In this retrospective study we evaluated the
proficiency of shelf autograft in the restoration of bone stock
as part of primary total hip replacement (THR) for hip dysplasia,
and in the results of revision arthroplasty after failure of the primary
arthroplasty. Of 146 dysplastic hips treated by THR and a shelf
graft, 43 were revised at an average of 156 months, 34 of which
were suitable for this study (seven hips were excluded because of
insufficient bone-stock data and two hips were excluded because
allograft was used in the primary THR). The acetabular bone stock
of the hips was assessed during revision surgery. The mean implant–bone
contact was 58% (50% to 70%) at primary THR and 78% (40% to 100%)
at the time of the revision, which was a significant improvement
(p <
0.001). At primary THR all hips had had a segmental acetabular
defect >
30%, whereas only five (15%) had significant segmental
bone defects requiring structural support at the time of revision.
In 15 hips (44%) no bone graft or metal augments were used during
revision. A total of 30 hips were eligible for the survival study. At a
mean follow-up of 103 months (27 to 228), two aseptic and two septic
failures had occurred. Kaplan-Meier survival analysis of the revision
procedures demonstrated a ten-year survival rate of 93.3% (95% confidence
interval (CI) 78 to 107) with clinical or radiological failure as
the endpoint. The mean Oxford hip score was 38.7 (26 to 46) for
non-revised cases at final follow-up. Our results indicate that the use of shelf autografts during
THR for dysplastic hips restores bone stock, contributing to the
favourable survival of the revision arthroplasty should the primary
procedure fail. Cite this article:
In Norway total joint replacement after hip dysplasia
is reported more commonly than in neighbouring countries, implying
a higher prevalence of the condition. We report on the prevalence
of radiological features associated with hip dysplasia in a population
of
2081 19-year-old Norwegians. The radiological measurements used
to define hip dysplasia were Wiberg’s centre-edge (CE) angle at
thresholds of <
20° and <
25°, femoral head extrusion index
<
75%, Sharp’s angle >
45°, an acetabular depth to width ratio
<
250 and the sourcil shape assessed subjectively. The whole
cohort underwent clinical examination of their range of hip movement,
body mass index (BMI), and Beighton hypermobility score, and were
asked to complete the EuroQol (EQ-5D) and Western Ontario and McMaster
Universities Osteoarthritis Index (WOMAC). The prevalence of hip
dysplasia in the cohort varied from 1.7% to 20% depending on the
radiological marker used. A Wiberg’s CE angle <
20° was seen
in 3.3% of the cohort: 4.3% in women and 2.4% in men. We found no
association between subjects with multiple radiological signs indicative
of dysplasia and BMI, Beighton score, EQ-5D or WOMAC. Although there
appears to be a high prevalence of hip dysplasia among 19-year-old
Norwegians, this is dependent on the radiological parameters applied. Cite this article:
Following the recall of modular neck hip stems
in July 2012, research into femoral modularity will intensify over
the next few years. This review aims to provide surgeons with an
up-to-date summary of the clinically relevant evidence. The development
of femoral modularity, and a classification system, is described.
The theoretical rationale for modularity is summarised and the clinical
outcomes are explored. The review also examines the clinically relevant problems
reported following the use of femoral stems with a modular neck. Joint replacement registries in the United Kingdom and Australia
have provided data on the failure rates of modular devices but cannot
identify the mechanism of failure. This information is needed to
determine whether modular neck femoral stems will be used in the
future, and how we should monitor patients who already have them implanted. 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:
Our understanding of the origin of hip pain in
degenerative disorders of the hip, including primary osteoarthritis, avascular
necrosis and femoroacetabular impingement (FAI), is limited. We
undertook a histological investigation of the nociceptive innervation
of the acetabular labrum, ligamentum teres and capsule of the hip,
in order to prove pain- and proprioceptive-associated marker expression.
These structures were isolated from 57 patients who had undergone
elective hip surgery (44 labral samples, 33 ligamentum teres specimens,
34 capsular samples; in 19 patients all three structures were harvested).
A total of
15 000 histological sections were prepared that were investigated
immunohistochemically for the presence of protein S-100, 68 kDa
neurofilament, neuropeptide Y, nociceptin and substance P. The tissues
were evaluated in six representative areas. Within the labrum, pain-associated free nerve ending expression
was located predominantly at its base, decreasing in the periphery.
In contrast, the distribution within the ligamentum teres showed
a high local concentration in the centre. The hip capsule had an
almost homogeneous marker expression in all investigated areas. This study showed characteristic distribution profiles of nociceptive
and pain-related nerve fibres, which may help in understanding the
origin of hip pain. Cite this article:
Using data from the Norwegian Hip Fracture Register,
8639 cemented and 2477 uncemented primary hemiarthroplasties for
displaced fractures of the femoral neck in patients aged > 70 years
were included in a prospective observational study. A total of 218
re-operations were performed after cemented and 128 after uncemented
procedures. Survival of the hemiarthroplasties was calculated using
the Kaplan-Meier method and hazard rate ratios (HRR) for revision
were calculated using Cox regression analyses. At five years the
implant survival was 97% (95% confidence interval (CI) 97 to 97)
for cemented and 91% (95% CI 87 to 94) for uncemented hemiarthroplasties.
Uncemented hemiarthroplasties had a 2.1 times increased risk of
revision compared with cemented prostheses (95% confidence interval
1.7 to 2.6, p < 0.001). The increased risk was mainly caused
by revisions for peri-prosthetic fracture (HRR = 17), aseptic loosening
(HRR = 17), haematoma formation (HRR = 5.3), superficial infection
(HRR = 4.6) and dislocation (HRR = 1.8). More intra-operative complications,
including intra-operative death, were reported for the cemented
hemiarthroplasties. However, in a time-dependent analysis, the HRR
for re-operation in both groups increased as follow-up increased. This study showed that the risk for revision was higher for uncemented
than for cemented hemiarthroplasties.
Using general practitioner records and hospital
notes and through direct telephone conversation with patients, we investigated
the accuracy of nine patient-reported complications gathered from
a self-completed questionnaire after elective joint replacement
surgery of the hip and knee. A total of 402 post-discharge complications
were reported after 8546 elective operations that were undertaken
within a three-year period. These were reported by 136 men and 240
women with a mean age of 71.8 years (34 to 93). A total of 319 reported
complications (79.4%; 95% confidence interval 75.4 to 83.3) were
confirmed to be correct. High rates of correct reporting were demonstrated
for infection (94.5%) and the need for further surgery (100%), whereas
the rates of reporting deep-vein thrombosis (DVT), pulmonary embolism,
myocardial infarction and stroke were lower (75% to 84.2%). Dislocation,
peri-prosthetic fractures and nerve palsy had modest rates of correct
reporting (36% to 57.1%). More patients who had knee surgery delivered
incorrect reports of dislocation (p = 0.001) and DVT (p = 0.013). Despite these variations, it appears that post-operative complications
may form part of a larger patient-reported outcome programme after
elective joint replacement surgery.
It is probable that both genetic and environmental
factors play some part in the aetiology of most cases of degenerative
hip disease. Geneticists have identified some single gene disorders
of the hip, but have had difficulty in identifying the genetics
of many of the common causes of degenerative hip disease. The heterogeneity
of the phenotypes studied is part of the problem. A detailed classification
of phenotypes is proposed. This study is based on careful documentation
of 2003 consecutive total hip replacements performed by a single
surgeon between 1972 and 2000. The concept that developmental problems
may initiate degenerative hip disease is supported. The influences
of gender, age and body mass index are outlined. Biomechanical explanations
for some of the radiological appearances encountered are suggested.
The body weight lever, which is larger than the abductor lever, causes
the abductor power to be more important than body weight. The possibility
that a deficiency in joint lubrication is a cause of degenerative
hip disease is discussed. Identifying the phenotypes may help geneticists
to identify genes responsible for degenerative hip disease, and
eventually lead to a definitive classification.
Autologous retransfusion and no-drainage are
both blood-saving measures in total hip replacement (THR). A new combined
intra- and post-operative autotransfusion filter system has been
developed especially for primary THR, and we conducted a randomised
controlled blinded study comparing this with no-drainage. A total of 204 THR patients were randomised to autologous blood
transfusion (ABT)
(n = 102) or no-drainage (n = 102). In the ABT group, a mean of
488 ml ( The use of a new intra- and post-operative autologous blood transfusion
filter system results in less total blood loss and a smaller maximum
decrease in haemoglobin levels than no-drainage following primary
THR. 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.
Patient expectations and their fulfilment are
an important factor in determining patient-reported outcome and satisfaction
of hip (THR) and knee replacement (TKR). The aim of this prospective
cohort study was to examine the expectations of patients undergoing
THR and TKR, and to identify differences in expectations, predictors
of high expectations and the relationship between the fulfilment
of expectations and patient-reported outcome measures. During the
study period, patients who underwent 346 THRs and 323 TKRs completed
an expectation questionnaire, Oxford score and Short-Form 12 (SF-12)
score pre-operatively. At one year post-operatively, the Oxford
score, SF-12, patient satisfaction and expectation fulfilment were
assessed. Univariable and multivariable analysis were performed.
Improvements in mobility and daytime pain were the most important
expectations in both groups. Expectation level did not differ between
THR and TKR. Poor Oxford score, younger age and male gender significantly
predicted high pre-operative expectations (p <
0.001). The level
of pre-operative expectation was not significantly associated with
the fulfilment of expectations or outcome. THR better met the expectations
identified as important by patients. TKR failed to meet expectations
of kneeling, squatting and stair climbing. High fulfilment of expectation
in both THR and TKR was significantly predicted by young age, greater
improvements in Oxford score and high pre-operative mental health
scores. The fulfilment of expectations was highly correlated with satisfaction.
Clinicians are often asked by patients, “When
can I drive again?” after lower limb injury or surgery. This question
is difficult to answer in the absence of any guidelines. This review
aims to collate the currently available evidence and discuss the
factors that influence the decision to allow a patient to return
to driving. There is currently insufficient evidence for any authoritative
body to determine fitness to drive. The lack of guidance could result
in patients being withheld from driving for longer than is necessary,
or returning to driving while still unsafe. Cite this article:
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.