We compared the rate of revision for instability
after total hip replacement (THR) when lipped and non-lipped acetabular
liners were used. We hypothesised that the use of a lipped liner
in a modular uncemented acetabular component reduces the risk of
revision for instability after primary THR. Using data from the
New Zealand Joint Registry, we found that the use of a lipped liner
was associated with a significantly decreased rate of revision for instability
and for all other indications. Adjusting for the size of the femoral
head, the surgical approach and the age and gender of the patient,
this difference remained strongly significant (p <
0.001). We conclude that evidence from the New Zealand registry suggests
that the use of lipped liners with modular uncemented acetabular
components is associated with a decreased rate of revision for instability
after primary THR. Cite this article:
Plasma levels of cobalt and chromium ions and
Metal Artefact Reduction Sequence (MARS)-MRI scans were performed
on patients with 209 consecutive, unilateral, symptomatic metal-on-metal
(MoM) hip arthroplasties. There was wide variation in plasma cobalt
and chromium levels, and MARS-MRI scans were positive for adverse reaction
to metal debris (ARMD) in 84 hips (40%). There was a significant
difference in the median plasma cobalt and chromium levels between
those with positive and negative MARS-MRI scans (p <
0.001).
Compared with MARS-MRI as the potential reference standard for the
diagnosis of ARMD, the sensitivity of metal ion analysis for cobalt
or chromium with a cut-off of >
7 µg/l was 57%. The specificity was
65%, positive predictive value was 52% and the negative predictive
value was 69% in symptomatic patients. A lowered threshold of >
3.5 µg/l for cobalt and chromium ion levels improved the sensitivity
and negative predictive value to 86% and 74% but at the expense
of specificity (27%) and positive predictive value (44%). Metal ion analysis is not recommended as a sole indirect screening
test in the surveillance of symptomatic patients with a MoM arthroplasty.
The investigating clinicians should have a low threshold for obtaining
cross-sectional imaging in these patients, even in the presence
of low plasma metal ion levels.
Adolescent idiopathic scoliosis affects about
3% of children. Non-operative measures are aimed at altering the natural
history to maintain the size of the curve below 40° at skeletal
maturity. The application of braces to treat spinal deformity pre-dates
the era of evidence-based medicine, and there is a paucity of irrefutable
prospective evidence in the literature to support their use and
their effectiveness has been questioned. This review considers this evidence. The weight of the evidence
is in favour of bracing over observation. The most recent literature
has moved away from addressing this question, and instead focuses
on developments in the design of braces and ways to improve compliance. Cite this article:
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 reviewed 123 second-generation uncemented total hip replacements performed on 115 patients by a single surgeon between 1993 and 1994. The acetabular component used in all cases was a fully porous-coated threaded hemispheric titanium shell (T-Tap ST) with a calcium ion stearate-free, isostatically compression-moulded polyethylene liner. The titanium femoral component used was a Taperloc with a reduced distal stem. No patient was lost to follow-up. Complete clinical and radiological follow-up was obtained for all 123 hips at a mean of 14 years (12 to 16). One femoral component was revised after a fracture, and three acetabular components for aseptic loosening. No additional femoral or acetabular components were judged loose by radiological criteria. Mild proximal femoral osteolysis was identified in two hips and minor acetabular osteolysis was present in four. The mean rate of penetration of the femoral head was 0.036 mm/year (0.000 to 0.227). These findings suggest that refinements in component design may be associated with excellent long-term fixation in cementless primary total hip replacement.
We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients’ quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively.
In this systematic review, our aim was to explore
whether or not patients are able to return to athletic activity
following lower limb joint replacement. We also investigated any evidence
as to whether participation in athletic activity post-joint replacement
increases complications and reduces implant survival. A PubMed, Embase and Sports Discus search was performed using
the MeSH terms ‘Sport’, ‘Athletic’, ‘Athlete’, ‘Physical’, ‘Activity’,
‘Arthroplasty’, ‘Total Hip Replacement’, ‘Hip Resurfacing’, ‘Total
Knee Replacement’, ‘Unicompartmental Knee Replacement’ and ‘Unicondylar
Knee Replacement’. From this search, duplications were excluded,
the remaining abstracts were reviewed and any unrelated to the search
terms were excluded. The remaining abstracts had their full papers
reviewed. Following joint replacement, participation in sporting activity
is common principally determined by pre-operative patient activity
levels, BMI and patient age. The type of joint replaced is of less
significance. Total time spent performing activity does not change
but tends to be at a lower intensity. There is little evidence in
the literature of an association between high activity levels and
early implant failure. Cite this article:
The aetiology of hallux valgus is almost certainly multifactoral.
The biomechanics of the first ray is a common factor to most. There
is very little literature examining the anatomy of the proximal
metatarsal articular surface and its relationship to hallux valgus
deformity. We examined 42 feet from 23 specimens in this anatomical dissection
study.Introduction
Methods
The June 2014 Spine Roundup360 looks at: spinal pedicle screws in paediatric patients; improving diagnosis in lumbar spine stenosis; back pain all in the head?; brace three patients, save one scoliosis operation; pedicle screws more often misplaced than one would think; and incidental dural tears usually no problem
We report the findings of an independent review
of 230 consecutive Birmingham hip resurfacings (BHRs) in 213 patients
(230 hips) at a mean follow-up of 10.4 years (9.6 to 11.7). A total
of 11 hips underwent revision; six patients (six hips) died from
unrelated causes; and 13 patients (16 hips) were lost to follow-up.
The survival rate for the whole cohort was 94.5% (95% confidence
interval (CI) 90.1 to 96.9). The survival rate in women was 89.1%
(95% CI 79.2 to 94.4) and in men was 97.5% (95% CI 92.4 to 99.2).
Women were 1.4 times more likely to suffer failure than men. For
each millimetre increase in component size there was a 19% lower
chance of a failure. The mean Oxford hip score was 45.0 (median
47.0, 28 to 48); mean University of California, Los Angeles activity
score was 7.4 (median 8.0, 3 to 9); mean patient satisfaction score
was 1.4 (median 1.0, 0 to 9). A total of eight hips had lysis in
the femoral neck and two hips had acetabular lysis. One hip had
progressive radiological changes around the peg of the femoral component.
There was no evidence of progressive neck narrowing between five
and ten years. Our results confirm that BHR provides good functional outcome
and durability for men, at a mean follow-up of ten years. We are
now reluctant to undertake hip resurfacing in women with this implant.
The purpose of this study was to evaluate whether concerns about the release of metal ions in metal-on-metal total hip replacements (THR) should be extended to patients with metal-bearing total disc replacements (TDR). Cobalt and chromium levels in whole blood and serum were measured in ten patients with a single-level TDR after a mean follow-up of 34.5 months (13 to 61) using inductively-coupled plasma mass spectrometry. These metal ion levels were compared with pre-operative control levels in 81 patients and with metal ion levels 12 months after metal-on-metal THR (n = 21) and resurfacing hip replacement (n = 36). Flexion-extension radiographs were used to verify movement of the TDR. Cobalt levels in whole blood and serum were significantly lower in the TDR group than in either the THR (p = 0.007) or the resurfacing group (p <
0.001). Both chromium levels were also significantly lower after TDR These results suggest that there is minimal cause for concern about high metal ion concentrations after TDR, as the levels appear to be only moderately elevated. However, spinal surgeons using a metal-on-metal TDR should still be aware of concerns expressed in the hip replacement literature about toxicity from elevated metal ion levels, and inform their patients appropriately.
The Bologna–Oxford (BOX) total ankle replacement
(TAR) was developed with the aim of achieving satisfactory pain-free
movement of the ankle. To date, only one single multicentre study
has reported its clinical results. The aim of this study was to
conduct an independent review of its mid-term results. We retrospectively reviewed a total of 60 prospectively followed
patients in whom 62 BOX TARs had been implanted between 2004 and
2008. We used the American Orthopedic Foot and Ankle Society (AOFAS)
score to assess the clinical results. Standardised radiographs taken
at the time of final follow-up were analysed by two observers. The
overall survival was 91.9% at a mean follow-up of 42.5 months (24
to 71). The mean AOFAS score had improved from 35.1 points (
The Oxford mobile-bearing unicompartmental knee
replacement (UKR) is an effective and safe treatment for osteoarthritis
of the medial compartment. The results in the lateral compartment
have been disappointing due to a high early rate of dislocation
of the bearing. A series using a newly designed domed tibial component
is reported. The first 50 consecutive domed lateral Oxford UKRs in 50 patients
with a mean follow-up of three years (2.0 to 4.3) were included.
Clinical scores were obtained prospectively and Kaplan-Meier survival
analysis was performed for different endpoints. Radiological variables
related to the position and alignment of the components were measured. One patient died and none was lost to follow-up. The cumulative
incidence of dislocation was 6.2% (95% confidence interval (CI)
2.0 to 17.9) at three years. Survival using revision for any reason
and aseptic revision was 94% (95% CI 82 to 98) and 96% (95% CI 85
to 99) at three years, respectively. Outcome scores, visual analogue
scale for pain and maximum knee flexion showed a significant improvement
(p <
0.001). The mean Oxford knee score was 43 ( Clinical results are excellent and short-term survival has improved
when compared with earlier series. The risk of dislocation remains
higher using a mobile-bearing UKR in the lateral compartment when
compared with the medial compartment. Patients should be informed
about this complication. To avoid dislocations, care must be taken
not to elevate the lateral joint line.
There is great variability in acetabular component
orientation following hip replacement. The aims of this study were
to compare the component orientation at impaction with the orientation
measured on post-operative radiographs and identify factors that
influence the difference between the two. A total of 67 hip replacements
(52 total hip replacements and 15 hip resurfacings) were prospectively
studied. Intra-operatively, the orientation of the acetabular component
after impaction relative to the operating table was measured using
a validated stereo-photogrammetry protocol. Post-operatively, the
radiographic orientation was measured; the mean inclination/anteversion
was 43° ( This study demonstrated that in order to achieve a specific radiographic
orientation target, surgeons should implant the acetabular component
5° less inclined and 8° more anteverted than their target. Great
variability (2 Cite this article:
Total shoulder replacement is a successful procedure for degenerative or some inflammatory diseases of the shoulder. However, fixation of the glenoid seems to be the main weakness with a high rate of loosening. The results using all-polyethylene components have been better than those using metal-backed components. We describe our experience with 35 consecutive total shoulder replacements using a new metal-backed glenoid component with a mean follow-up of 75.4 months (48 to 154). Our implant differs from others because of its mechanism of fixation. It has a convex metal-backed bone interface and the main stabilising factor is a large hollow central peg. The patients were evaulated with standard radiographs and with the Constant Score, the Simple Shoulder Test and a visual analogue scale. All the scores improved and there was no loosening, no polyethylene-glenoid disassembly and no other implant-related complications. We conclude that a metal-backed glenoid component is a good option in total shoulder replacement with no worse results than of those using a cemented all-polyethylene prosthesis.
An international faculty of orthopaedic surgeons
presented their work on the current challenges in hip surgery at
the London Hip Meeting which was attended by over
400 delegates. The topics covered included femoroacetabular impingement, thromboembolic
phenomena associated with hip surgery, bearing surfaces (including metal-on-metal
articulations), outcomes of hip replacement surgery and revision
hip replacement. We present a concise report of the current opinions
on hip surgery from this meeting with appropriate references to
the current literature.
We are entering a new era with governmental bodies
taking an increasingly guiding role, gaining control of registries,
demanding direct access with release of open public information
for quality comparisons between hospitals. This review is written
by physicians and scientists who have worked with the Swedish Knee
Arthroplasty Register (SKAR) periodically since it began. It reviews
the history of the register and describes the methods used and lessons
learned. Cite this article:
Peri-articular soft-tissue masses or ‘pseudotumours’
can occur after large-diameter metal-on-metal (MoM) resurfacing
of the hip and conventional total hip replacement (THR). Our aim
was to assess the incidence of pseudotumour formation and to identify
risk factors for their formation in a prospective cohort study. A total of 119 patients who underwent 120 MoM THRs with large-diameter
femoral heads between January 2005 and November 2007 were included
in the study. Outcome scores, serum metal ion levels, radiographs
and CT scans were obtained. Patients with symptoms or an identified
pseudotumour were offered MRI and an ultrasound-guided biopsy. There were 108 patients (109 hips) eligible for evaluation by
CT scan at a mean follow-up of 3.6 years (2.5 to 4.5); 42 patients
(39%) were diagnosed with a pseudotumour. The hips of 13 patients
(12%) were revised to a polyethylene acetabular component with small-diameter
metal head. Patients with elevated serum metal ion levels had a
four times increased risk of developing a pseudotumour. This study shows a substantially higher incidence of pseudotumour
formation and subsequent revisions in patients with MoM THRs than
previously reported. Because most revision cases were identified
only after an intensive screening protocol, we recommend close monitoring
of patients with MoM THR.
The Exeter femoral stem is a double-tapered highly
polished collarless cemented implant with good long-term clinical
results. In order to determine why the stem functions well we have
undertaken a long-term radiostereometric analysis (RSA) study. A total of 20 patients undergoing primary Exeter total hip replacement
for osteoarthritis using the Hardinge approach were recruited and
followed with RSA for ten years. The stems progressively subsided
and internally rotated with posterior head migration. The mean subsidence
was 0.7 mm (95% confidence interval (CI) 0.5 to 0.9) at two years
and 1.3 mm (95% CI 1.0 to 1.6) at ten years. The mean posterior
migration of the head was 0.7 mm (95% CI 0.5 to 0.9) at two years
and 1.2 mm (95% CI 1.0 to 1.4) at ten years. There was no significant
cement restrictor migration. The Exeter stem continues to subside slowly into the cement mantle
in the long term. This appears to compress the cement and the cement
bone interface, contributing to secure fixation in the long term. Cite this article:
Radiostereometric analysis (RSA) can detect early
micromovement in unstable implant designs which are likely subsequently
to have a high failure rate. In 2010, the Articular Surface Replacement
(ASR) was withdrawn because of a high failure rate. In 19 ASR femoral
components, the mean micromovement over the first two years after implantation
was 0.107 mm ( We conclude that the ASR femoral component achieves initial stability
and that early migration is not the mode of failure for this resurfacing
arthroplasty.