The aim of this study was to assess the current trends in the estimation of survival and the preferred forms of treatment of pathological fractures among national and international general and oncological orthopaedic surgeons, and to explore whether improvements in the management of these patients could be identified in this way. All members of the Dutch Orthopaedic Society (DOS) and the European Musculoskeletal Oncology Society (EMSOS) were invited to complete a web-based questionnaire containing 12 cases.Aims
Materials and Methods
Increasing innovation in rapid prototyping (RP)
and additive manufacturing (AM), also known as 3D printing, is bringing
about major changes in translational surgical research. This review describes the current position in the use of additive
manufacturing in orthopaedic surgery. Cite this article:
Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep. We cemented six collarless polished tapered (CPT) stems (two stems each of small, medium and large sizes) into composite femurs that had been reamed with a large CPT rasp to achieve various thicknesses of the cement mantle. Two or three tantalum balls were implanted in the proximal cement in each femur. A cyclic loading test was then performed for each stem. The migration of the balls was measured three-dimensionally, using a micro-computed tomography (CT) scanner, before and after loading. A digital displacement gauge was positioned at the stem shoulder, and stem subsidence was measured continuously by the gauge. Final stem subsidence was measured at the balls at the end of each stem.Objectives
Methods
Computed tomography (CT) plays an important role in evaluating wear and periacetabular osteolysis (PAO) in total hip replacements. One concern with CT is the high radiation exposure since standard pelvic CT provides approximately 3.5 millisieverts (mSv) of radiation exposure, whereas a planar radiographic examination with three projections totals approximately 0.5 mSv. The objective of this study was to evaluate the lowest acceptable radiation dose for dual-energy CT (DECT) images when measuring wear and periacetabular osteolysis in uncemented metal components. A porcine pelvis with bilateral uncemented hip prostheses and with known linear wear and acetabular bone defects was examined in a third-generation multidetector DECT scanner. The examinations were performed with four different radiation levels both with and without iterative reconstruction techniques. From the high and low peak kilo voltage acquisitions, polychrmoatic images were created together with virtual monochromatic images of energies 100 kiloelectron volts (keV) and 150 keV.Objectives
Materials and Methods
The aim of this study was to compare the survivorship and radiographic
outcomes at ten-year follow-up of three prospective consecutive
series of patients each of which received a different design of
cementless femoral components for total hip arthroplasty (THA). In Cohort 1, 91 consecutive patients (100 hips) underwent THA
with a cementless porous-coated anatomic femoral stem (PCA) between
October 1983 and January 1986. In Cohort 2, 86 consecutive patients
(100 hips) underwent THA with an extensively porous-coated cementless
femoral stem (Prodigy) between June 1994 and October 1997. In Cohort
3, 88 consecutive patients (100 hips) underwent THA with a proximally
porous-coated triple-tapered cementless stem (Summit) between April
2002 and October 2003. All three groups underwent prospective clinical
and radiographic evaluation.Aims
Patients and Methods
The diagnosis of periprosthetic joint infection (PJI) remains
demanding due to limitations of all the available diagnostic tests.
The synovial fluid marker, α-defensin, is a promising adjunct for
the assessment of potential PJI. The purpose of this study was to
investigate the qualitative assessment of α-defensin, using Synovasure
to detect or exclude periprosthetic infection in total joint arthroplasty. We studied 50 patients (28 women, 22 men, mean age 65 years;
20 to 89) with a clinical indication for revision arthroplasty who
met the inclusion criteria of this prospective diagnostic study.
The presence of α-defensin was determined using the qualitative
Synovasure test and compared with standard diagnostic methods for
PJI. Based on modified Musculoskeletal Infection Society (MSIS)
criteria, 13 cases were categorised as septic and 36 as aseptic revisions.
One test was inconclusive.Aims
Patients and Methods
The high revision rates of the DePuy Articular Surface Replacement (ASR) and the DePuy ASR XL (the total hip arthroplasty (THA) version) have led to questions over the viability of metal-on-metal (MoM) hip joints. Some designs of MoM hip joint do, however, have reasonable mid-term performance when implanted in appropriate patients. Investigations into the reasons for implant failure are important to offer help with the choice of implants and direction for future implant designs. One way to assess the performance of explanted hip prostheses is to measure the wear (in terms of material loss) on the joint surfaces. In this study, a coordinate measuring machine (CMM) was used to measure the wear on five failed cementless Biomet Magnum/ReCap/ Taperloc large head MoM THAs, along with one Biomet ReCap resurfacing joint. Surface roughness measurements were also taken. The reason for revision of these implants was pain and/or adverse reaction to metal debris (ARMD) and/or elevated blood metal ion levels.Objectives
Methods
Alarm over the reported high failure rates for metal-on-metal (MoM) hip implants as well as their potential for locally aggressive Adverse Reactions to Metal Debris (ARMDs) has prompted government agencies, internationally, to recommend the monitoring of patients with MoM hip implants. Some have advised that a blood ion level >7 µg/L indicates potential for ARMDs. We report a systematic review and meta-analysis of the performance of metal ion testing for ARMDs. We searched MEDLINE and EMBASE to identify articles from which it was possible to reconstruct a 2 × 2 table. Two readers independently reviewed all articles and extracted data using explicit criteria. We computed a summary receiver operating curve using a Bayesian random-effects hierarchical model.Objectives
Methods
The widely used and well-proven Palacos R (a.k.a. Refobacin Palacos
R) bone cement is no longer commercially available and was superseded
by Refobacin bone cement R and Palacos R + G in 2005. However, the
performance of these newly introduced bone cements have not been
tested in a phased evidence-based manner, including roentgen stereophotogrammetric
analysis (RSA). In this blinded, randomised, clinical RSA study, the migration
of the Stanmore femoral component was compared between Refobacin
bone cement R and Palacos R + G in 62 consecutive total hip arthroplasties.
The primary outcome measure was femoral component migration measured
using RSA and secondary outcomes were Harris hip score (HHS), Hip
disability and Osteoarthritis Outcome Score (HOOS), EuroQol 5D (EQ-5D)
and Short Form 36 (SF-36).Aims
Patients and Methods
We wanted to investigate regional variations in the organisms
reported to be causing peri-prosthetic infections and to report
on prophylaxis regimens currently in use across England. Analysis of data routinely collected by Public Health England’s
(PHE) national surgical site infection database on elective primary
hip and knee arthroplasty procedures between April 2010 and March
2013 to investigate regional variations in causative organisms.
A separate national survey of 145 hospital Trusts (groups of hospitals
under local management) in England routinely performing primary
hip and/or knee arthroplasty was carried out by standard email questionnaire.Objectives
Methods
Modular junctions are ubiquitous in contemporary hip arthroplasty. The head-trunnion junction is implicated in the failure of large diameter metal-on-metal (MoM) hips which are the currently the topic of one the largest legal actions in the history of orthopaedics (estimated costs are stated to exceed $4 billion). Several factors are known to influence the strength of these press-fit modular connections. However, the influence of different head sizes has not previously been investigated. The aim of the study was to establish whether the choice of head size influences the initial strength of the trunnion-head connection. Ti-6Al-4V trunnions (n = 60) and two different sizes of cobalt-chromium (Co-Cr) heads (28 mm and 36 mm; 30 of each size) were used in the study. Three different levels of assembly force were considered: 4 kN; 5 kN; and 6 kN (n = 10 each). The strength of the press-fit connection was subsequently evaluated by measuring the pull-off force required to break the connection. The statistical differences in pull-off force were examined using a Kruskal–Wallis test and two-sample Mann–Whitney U test. Finite element and analytical models were developed to understand the reasons for the experimentally observed differences.Objectives
Materials and Methods
The long-term survival of the cementless Spotorno
CLS femoral component in patients aged >
50 years at the time of
arthroplasty was investigated. Survivorship analysis of a consecutive
series of 85 patients (100 hips; under 50 years of age at a mean
follow-up of 18.4 years (16.3 to 20.8)) was performed. The clinical
and radiographic outcomes were satisfactory. The overall rate of
survival of the femoral component was 93.5% (95% confidence interval
(CI), 90.9 to 96.1) after 19 years. Survival with revision for aseptic
loosening as the end point was 95.7% (95% CI 93.6 to 97.8%) at 19
years. This study demonstrates an excellent long-term survival of the
Spotorno CLS femoral component after 16 to 20 years in young patients
undergoing total hip arthroplasty. Cite this article:
High failure rates of metal-on-metal hip arthroplasty implants have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices. The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage. We aimed to identify validated surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty (THA). We conducted a systematic review of studies evaluating surrogate markers for predicting long-term outcome in primary THA. Long-term outcome was defined as revision rate of an implant at ten years according to National Institute of Health and Care Excellence guidelines. We conducted a search of Medline and Embase (OVID) databases. Separate search strategies were devised for the Cochrane database and Google Scholar. Each search was performed to include articles from the date of their inception to June 8, 2015.Objectives
Methods
We compared the incidence of pseudotumours after
large head metal-on-metal (MoM) total hip arthroplasty (THA) with
that after conventional metal-on-polyethylene (MoP) THA and assessed
the predisposing factors to pseudotumour formation. From a previous randomised controlled trial which compared large
head (38 mm to 60 mm) cementless MoM THA with conventional head
(28 mm) cementless MoP THA, 93 patients (96 THAs: 41 MoM (21 males,
20 females, mean age of 64 years, standard deviation ( The incidence of pseudotumours, measured using a standardised
CT protocol was 22 (53.7%) after MoM THA and 12 (21.8%) after MoP
THA. Women with a MoM THA were more likely to develop a pseudotumour
than those with a MoP THA (15 Contrary to popular belief, pseudotumours occur frequently around
MoP THAs. Women with a MoM THA and an elevated cobalt level are
at greatest risk. In this study, pseudotumours had no effect on
the functional outcome after either large head MoM or conventional
MoP THA. Cite this article:
The August 2015 Research Roundup360 looks at: Lightbulbs, bleeding and procedure durations; Infection and rheumatoid agents; Infection rates and ‘bundles of care’ revisited; ACI: new application for a proven technology?; Hydrogel coating given the thumbs up; Hydroxyapatite as a smart coating?
Hip resurfacing arthroplasty (HRA) is an alternative to conventional
total hip arthroplasty for patients with osteonecrosis (ON) of the
femoral head. Our aim was to report the long-term outcome of HRA,
which is not currently known. Long-term survivorship, clinical scores and radiographic results
for 82 patients (99 hips) treated with HRA for ON over a period
of 18 years were reviewed retrospectively. The mean age of the 67
men and 15 women at the time of surgery was 40.8 years (14 to 64).
Patients were resurfaced regardless of the size of the osteonecrotic
lesion.Aims
Patients and Methods
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:
We report the clinical and radiographic outcomes
of 208 consecutive femoral revision arthroplasties performed in 202
patients (119 women, 83 men) between March 1991 and December 2007
using the X-change Femoral Revision System, fresh-frozen morcellised
allograft and a cemented polished Exeter stem. All patients were
followed prospectively. The mean age of the patients at revision
was 65 years (30 to 86). At final review in December 2013 a total
of 130 patients with 135 reconstructions (64.9%) were alive and
had a non re-revised femoral component after a mean follow-up of
10.6 years (4.7 to 20.9). One patient was lost to follow-up at six
years, and their data were included up to this point.
Re-operation for any reason was performed in 33 hips (15.9%), in
13 of which the femoral component was re-revised (6.3%). The mean
pre-operative Harris hip score was 52 (19 to 95) (n = 73) and improved
to 80 (22 to 100) (n = 161) by the last follow-up. Kaplan–Meier
survival with femoral re-revision for any reason as the endpoint
was 94.9% (95% confidence intervals (CI) 90.2 to 97.4) at ten years;
with femoral re-revision for aseptic loosening as the endpoint it was
99.4% (95% CI 95.7 to 99.9); with femoral re-operation for any reason
as the endpoint it was 84.5% (95% CI 78.3 to 89.1); and with subsidence ≥ 5
mm it was 87.3% (95% CI 80.5 to 91.8). Femoral revision with the
use of impaction allograft bone grafting and a cemented polished
stem results in a satisfying survival rate at a mean of ten years’ follow-up. Cite this article:
It is becoming increasingly common for a patient
to have ipsilateral hip and knee replacements. The inter-prosthetic (IP)
distance, the distance between the tips of hip and knee prostheses,
has been thought to be associated with an increased risk of IP fracture.
Small gap distances are generally assumed to act as stress risers,
although there is no real biomechanical evidence to support this. The purpose of this study was to evaluate the influence of IP
distance, cortical thickness and bone mineral density on the likelihood
of an IP femoral fracture. A total of 18 human femur specimens were randomised into three
groups by bone density and cortical thickness. For each group, a
defined IP distance of 35 mm, 80 mm or 160 mm was created by choosing
the appropriate lengths of component. The maximum fracture strength
was determined using a four-point bending test. The fracture force of all three groups was similar (p = 0.498).
There was a highly significant correlation between the cortical
area and the fracture strength (r = 0.804, p <
0.001), whereas
bone density showed no influence. This study suggests that the IP distance has little influence
on fracture strength in IP femoral fractures: the thickness of the
cortex seems to be the decisive factor. Cite this article:
