The June 2014 Hip &
Pelvis Roundup360 looks at: Modular femoral necks: early signs are not good; is corrosion to blame for modular neck failures; metal-on-metal is not quite a closed book; no excess failures in fixation of displaced femoral neck fractures; noise no problem in hip replacement; heterotopic ossification after hip arthroscopy: are NSAIDs the answer?; thrombotic and bleeding events surprisingly low in total joint replacement; and the elephant in the room: complications and surgical volume.
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 December 2015 Hip &
Pelvis Roundup360 looks at: Vitamin E infusion helpful in polyethylene; Hip replacement in fracture and arthritis; Non-surgical treatment for arthritis; Cost and approach in hip surgery; Who does well in FAI surgery?; AAOS Thromboembolism guidelines; Thromboprophylaxis and periprosthetic joint infection; Fluid collections not limited to metal-on-metal THR
Platelet-leucocyte gel (PLG), a new biotechnological blood product, has hitherto been used primarily to treat chronic ulcers and to promote soft-tissue and bone regeneration in a wide range of medical fields. In this study, the antimicrobial efficacy of PLG against Staphylococcus aureus (ATCC 25923) was investigated in a rabbit model of osteomyelitis. Autologous PLG was injected into the tibial canal after inoculation with Staph. aureus. The prophylactic efficacy of PLG was evaluated by microbiological, radiological and histological examination. Animal groups included a treatment group that received systemic cefazolin and a control group that received no treatment. Treatment with PLG or cefazolin significantly reduced radiological and histological severity scores compared to the control group. This result was confirmed by a significant reduction in the infection rate and the number of viable bacteria. Although not comparable to cefazolin, PLG exhibited antimicrobial efficacy in vivo and therefore represents a novel strategy to prevent bone infection in humans.
Failure of bone repair is a challenging problem in the management of fractures. There is a limited supply of autologous bone grafts for treating nonunions, with associated morbidity after harvesting. There is need for a better source of cells for repair. Mesenchymal stem cells (MSCs) hold promise for healing of bone because of their capacity to differentiate into osteoblasts and their availability from a wide variety of sources. Our review aims to evaluate the available clinical evidence and recent progress in strategies which attempt to use autologous and heterologous MSCs in clinical practice, including genetically-modified MSCs and those grown on scaffolds. We have compared various procedures for isolating and expanding a sufficient number of MSCs for use in a clinical setting. There are now a number of clinical studies which have shown that implantation of MSCs is an effective, safe and durable method for aiding the repair and regeneration of bone.
The October 2015 Hip &
Pelvis Roundup360 looks at: Smoking and complications in arthroplasty; Smoking cessation beneficial in arthroplasty; Intermediate care and arthroplasty; Do we still need cell salvage?; Femoroacetabular impingement in the Japanese population; Trunnionosis or taperosis and geometry; Decontamination for staphylococcus aureus works!; Policeman or opportunity? Quality improvement with registries; Death rates higher in readmission to other hospitals
The conventional method for reconstructing acetabular
bone loss at revision surgery includes using structural bone allograft.
The disadvantages of this technique promoted the advent of metallic
but biocompatible porous implants to fill bone defects enhancing
initial and long-term stability of the acetabular component. This
paper presents the indications, surgical technique and the outcome
of using porous metal acetabular augments for reconstructing acetabular
defects. Cite this article:
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.
Metal artefact reduction (MAR) MRI is now widely
considered to be the standard for imaging metal-on-metal (MoM) hip
implants. The Medicines and Healthcare Products Regulatory Agency
(MHRA) has recommended cross-sectional imaging for all patients
with symptomatic MoM bearings. This paper describes the natural
history of MoM disease in a 28 mm MoM total hip replacement (THR)
using MAR MRI. Inclusion criteria were patients with MoM THRs who had
not been revised and had at least two serial MAR MRI scans. All
examinations were reported by an experienced observer and classified
as A (normal), B (infection) or C1–C3 (mild, moderate, severe MoM-related
abnormalities). Between 2002 and 2011 a total of 239 MRIs were performed
on 80 patients (two to four scans per THR); 63 initial MRIs (61%)
were normal. On subsequent MRIs, six initially normal scans (9.5%)
showed progression to a disease state; 15 (15%) of 103 THRs with
sequential scans demonstrated worsening disease on subsequent imaging. Most patients with a MoM THR who do not undergo early revision
have normal MRI scans. Late progression (from normal to abnormal,
or from mild to more severe MoM disease) is not common and takes
place over several years. Cite this article:
The aim of this study was to establish the natural
course of unrevised asymptomatic pseudotumours after metal-on-metal
(MoM) hip resurfacing during a six- to 12-month follow-up period.
We used repeated metal artefact reduction sequence (MARS)-magnetic
resonance imaging (MRI), serum metal ion analysis and clinical examination to
study 14 unrevised hips (mean patient age 52.7 years, 46 to 68,
5 female, 7 male) with a pseudotumour and 23 hips (mean patient
age 52.8 years, 38 to 69, 7 female, 16 male) without a pseudotumour.
The mean post-operative time to the first MARS-MRI scan was 4.3 years
(2.2 to 8.3), and mean time between the first and second MARS-MRI scan
was eight months (6 to 12). At the second MRI scan, the grade of
severity of the pseudotumour had not changed in 35 hips. One new
pseudotumour (Anderson C2 score, moderate) was observed, and one
pseudotumour was downgraded from C2 (moderate) to C1 (mild). In
general, the characteristics of the pseudotumours hardly changed. Repeated MARS-MRI scans within one year in patients with asymptomatic
pseudotumours after MoM hip resurfacing showed little or no variation.
In 23 patients without pseudotumour, one new asymptomatic pseudotumour
was detected. This is the first longitudinal study on the natural history of
pseudotumours using MARS-MRI scans in hip resurfacing, and mirrors
recent results for 28 mm diameter MoM total hip replacement. Cite this article:
Hip fracture is a common injury associated with
high mortality, long-term disability and huge socio-economic burden.
Yet there has been relatively little research into best treatment,
and evidence that has been generated has often been criticised for
its poor quality. Here, we discuss the advances made towards overcoming
these criticisms and the future directions for hip fracture research:
how co-ordinating existing national infrastructures and use of now
established clinical research networks will likely go some way towards
overcoming the practical and financial challenges of conducting
large trials. We highlight the importance of large collaborative
pragmatic trials to inform decision/policy makers and the progress
made towards reaching a consensus on a core outcome set to facilitate data
pooling for evidence synthesis and meta-analysis. These advances and future directions are a priority in order
to establish the high-quality evidence base required for this important
group of patients. 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 June 2013 Foot &
Ankle Roundup360 looks at: soft-tissue pain following arthroplasty; pigmented villonodular synovitis of the foot and ankle; ankles, allograft and arthritis; open calcaneal fracture; osteochondral lesions in the longer term; severe infections in diabetic feet; absorbable first ray fixation; and showering after foot surgery.
We report the clinical and radiological outcomes
of a series of contemporary cementless ceramic-on-ceramic total hip
replacements (THRs) at ten years in patients aged ≤ 55 years of
age. Pre- and post-operative activity levels are described. A total
of 120 consecutive ceramic cementless THRs were performed at a single
centre in 110 patients from 1997 to 1999. The mean age of the patients
at operation was 45 years (20 to 55). At ten years, four patients
had died and six were lost to follow-up, comprising ten hips. The
mean post-operative Harris hip score was 94.7 (55 to 100). Radiological
analysis was undertaken in 90 available THRs of the surviving 106
hips at final review: all had evidence of stable bony ingrowth,
with no cases of osteolysis. Wear was undetectable. There were four
revisions. The survival for both components with revision for any
cause as an endpoint was 96.5% (95% confidence interval 94.5 to
98.7). The mean modified University of California, Los Angeles activity
level rose from a mean of 6.4 (4 to 10) pre-operatively to 9.0 (6
to 10) at the ten-year post-operative period. Alumina ceramic-on-ceramic bearings in cementless primary THR
in this series have resulted in good clinical and radiological outcomes
with undetectable rates of wear and excellent function in the demanding
younger patient group at ten years. Cite this article:
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:
We reviewed the literature on the currently available
choices of bearing surface in total hip replacement (THR). We present
a detailed description of the properties of articulating surfaces
review the understanding of the advantages and disadvantages of
existing bearing couples. Recent technological developments in the
field of polyethylene and ceramics have altered the risk of fracture
and the rate of wear, although the use of metal-on-metal bearings has
largely fallen out of favour, owing to concerns about reactions
to metal debris. As expected, all bearing surface combinations have
advantages and disadvantages. A patient-based approach is recommended,
balancing the risks of different options against an individual’s
functional demands. Cite this article:
This multicentre prospective clinical trial aimed
to determine whether early administration of alendronate (ALN) delays
fracture healing after surgical treatment of fractures of the distal
radius. The study population comprised 80 patients (four men and
76 women) with a mean age of 70 years (52 to 86) with acute fragility
fractures of the distal radius requiring open reduction and internal
fixation with a volar locking plate and screws. Two groups of 40 patients
each were randomly allocated either to receive once weekly oral
ALN administration (35 mg) within a few days after surgery and continued
for six months, or oral ALN administration delayed until four months
after surgery. Postero-anterior and lateral radiographs of the affected
wrist were taken monthly for six months after surgery. No differences
between groups was observed with regard to gender (p = 1.0), age
(p = 0.916), fracture classification (p = 0.274) or bone mineral
density measured at the spine (p = 0.714). The radiographs were
assessed by three independent assessors. There were no significant
differences in the mean time to complete cortical bridging observed
between the ALN group (3.5 months ( Cite this article:
An ongoing prospective study to investigate failing metal-on-metal
hip prostheses was commenced at our centre in 2008. We report on
the results of the analysis of the first consecutive 126 failed
mated total hip prostheses from a single manufacturer. Analysis was carried out using highly accurate coordinate measuring
to calculate volumetric and linear rates of the articular bearing
surfaces and also the surfaces of the taper junctions. The relationship
between taper wear rates and a number of variables, including bearing
diameter and orientation of the acetabular component, was investigated.Objectives
Methods
Metal-on-metal hip arthroplasty gained significant
favor in the first decade of the millennium. However, the past several
years have seen increasing reports of failure, pseudotumor and other
adverse reactions. This study presents the results of a single center’s
15-year experience with metal-on-metal total hip arthroplasty as
strong evidence that metal-on-metal is going, going, gone.
This systematic review of the literature summarises
the clinical experience with ceramic-on-ceramic hip bearings over
the past 40 years and discusses the concerns that exist in relation
to the bearing combination. Loosening, fracture, liner chipping
on insertion, liner canting and dissociation, edge-loading and squeaking
have all been reported, and the relationship between these issues
and implant design and surgical technique is investigated. New design
concepts are introduced and analysed with respect to previous clinical
experience.