We evaluated the accuracy with which a custom-made
acetabular component could be positioned at revision arthroplasty
of the hip in patients with a Paprosky type 3 acetabular defect. A total of 16 patients with a Paprosky type 3 defect underwent
revision surgery using a custom-made trabecular titanium implant.
There were four men and 12 women with a median age of 67 years (48
to 79). The planned inclination (INCL), anteversion (AV), rotation
and centre of rotation (COR) of the implant were compared with the post-operative
position using CT scans. A total of seven implants were malpositioned in one or more parameters:
one with respect to INCL, three with respect to AV, four with respect
to rotation and five with respect to the COR. To the best of our knowledge, this is the first study in which
CT data acquired for the pre-operative planning of a custom-made
revision acetabular implant have been compared with CT data on the
post-operative position. The results are encouraging. Cite this article:
The aim of this independent multicentre study was to assess the
mid-term results of mobile bearing unicondylar knee arthroplasty
(UKA) for isolated lateral osteoarthritis of the knee joint. We retrospectively evaluated 363 consecutive, lateral UKAs (346
patients) performed using the Oxford domed lateral prosthesis undertaken
in three high-volume knee arthroplasty centres between 2006 and
2014. Mean age of the patients at surgery was 65 years (36 to 88)
with a mean final follow-up of 37 months (12 to 93)Aims
Patients and Methods
α-defensin is a biomarker which has been described as having
a high degree of accuracy in the diagnosis of periprosthetic joint
infection (PJI). Current meta-analyses are based on the α-defensin
laboratory-based immunoassay rather than the quick on-table lateral
flow test kit. This study is the first meta-analysis to compare the
accuracy of the α-defensin laboratory-based immunoassay and the
lateral flow test kit for the diagnosis of PJI. A systematic review was performed according to the Preferred
Reporting Items for Systematic Reviews and Meta-Analyses guidelines.
Inclusion criteria were all clinical studies where the diagnosis
of PJI was uncertain. All studies selected used the Musculoskeletal
Infection Society (MSIS) or modified MSIS criteria. Two independent
reviewers reviewed the studies and extracted data. A meta-analysis
of results was carried out: pooled sensitivity, specificity, positive
and negative likelihood ratio, heterogeneity and areas under curves
are reported.Aims
Materials and Methods
We present the ten-year data of a cohort of patients, aged between
18 and 65 years (mean age 52.7 years; 19 to 64), who underwent total
hip arthroplasty. Patients were randomised to be treated with a
cobalt-chrome (CoCr) femoral head with an ultra-high molecular weight
polyethylene (UHMWPE), highly cross-linked polyethylene (XLPE) or
ceramic-on-ceramic (CoC) bearing surface. A total of 102 hips (91 patients) were randomised into the three
groups. At ten years, 97 hips were available for radiological and
functional follow-up. Two hips (two patients) had been revised (one
with deep infection and one for periprosthetic fracture) and three
were lost to follow-up. Radiological analysis was performed using
a validated digital assessment programme to give linear, directional
and volumetric wear of the two polyethylene groups.Aims
Patients and Methods
Unicompartmental knee arthroplasty (UKA) is a potential treatment
for isolated bone on bone osteoarthritis when limited to a single
compartment. The risk for revision of UKA is three times higher
than for total knee arthroplasty (TKA). The aim of this review was
to discuss the different revision options after UKA failure. A search was performed for English language articles published
between 2006 and 2016. After reviewing titles and abstracts, 105
papers were selected for further analysis. Of these, 39 papers were
deemed to contain clinically relevant data to be included in this review.Objectives
Materials and Methods
Excision of the proximal femur for tumour with
prosthetic reconstruction using a bipolar femoral head places a considerable
load on the unreplaced acetabulum. We retrospectively reviewed the changes which occur around the
affected hip joint by evaluating the post-operative radiographs
of 65 consecutive patients who underwent proximal prosthetic arthroplasty
of the femur, and in whom an acetabular component had not been used.
There were 37 men and 28 women with a mean age of 57.3 years (17
to 93). Radiological assessment included the extent of degenerative
change in the acetabulum, heterotopic ossification, and protrusio
acetabuli. The mean follow-up was 9.1 years (2 to 11.8). Degenerative changes
in the acetabulum were seen in three patients (4.6%), Brooker grade
1 or 2 heterotopic ossification in 17 (26%) and protrusion of the
prosthetic head in nine (13.8%). A total of eight patients (12.3%) needed a revision. Five were
revised to the same type of prosthesis and three (4.6%) were converted
to a total hip arthroplasty. We conclude that radiological evidence of degenerative change,
heterotopic ossification and protrusion occur in a few patients
who undergo prosthetic arthroplasty of the proximal femur for tumour.
The limited extent of these changes and the lack of associated symptoms
do not justify the routine arthroplasty of the acetabulum in these patients. Cite this article:
The aim of this study was to determine whether the rates of revision
for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle
components varied according to the year of the initial operation,
and compare these with the rates of revision for other designs of
MoM THA. Data from the National Joint Registry for England and Wales included
36 mm MoM THAs with Pinnacle acetabular components which were undertaken
between 2003 and 2012 with follow-up for at least five years (n
= 10 776) and a control group of other MoM THAs (n = 13 817). The
effect of the year of the primary operation on all-cause rates of revision
was assessed using Cox regression and interrupted time-series analysis.Aims
Patients and Methods
Patients with flexion instability after total knee arthroplasty
(TKA) often present with a recurrent effusion, which may be a haemarthrosis.
While the radiographic factors contributing to flexion instability
have been elucidated, the clinical diagnosis remains challenging.
Our aim, in this study, was to determine the mean white cell count
and differential profile in pre-operative aspirations of synovial
fluid in a consecutive series of patients undergoing revision TKA
for flexion instability. Between 2000 and 2010, 60 patients undergoing aseptic revision
TKA for flexion instability were identified. The results of the
pre-operative aspiration of synovial fluid were available for 53
patients (88%). These patients were 1:2 matched to 106 patients
who underwent aseptic TKA for indications other than flexion instability.
The mean age of the patients at revision TKA was 65 years (44 to
82) and 55% were women. The mean follow-up was 4.3 years (2 to 10.2).Aims
Patients and Methods
Our aim was to prepare a systematic review and meta-analysis
to compare the outcomes of cemented and cementless hemiarthroplasty
of the hip, in elderly patients with a fracture of the femoral neck,
to investigate the mortality, complications, length of stay in hospital,
blood loss, operating time and functional results. A systematic review and meta-analysis was conducted following
the Preferred Reporting Items for Systematic Reviews and Meta-Analyses
guidelines on randomised controlled trials (RCTs), studying current
generation designs of stem only. The synthesis of results was done
of pooled data, with a fixed effects or random effects model, based on
heterogeneity.Aims
Materials and Methods
The diagnosis of periprosthetic joint infection (PJI) is difficult and requires a battery of tests and clinical findings. The purpose of this review is to summarize all current evidence for common and new serum biomarkers utilized in the diagnosis of PJI. We searched two literature databases, using terms that encompass all hip and knee arthroplasty procedures, as well as PJI and statistical terms reflecting diagnostic parameters. The findings are summarized as a narrative review.Objectives
Methods
Malalignment of the tibial component could influence the long-term survival of a total knee arthroplasty (TKA). The object of this study was to investigate the biomechanical effect of varus and valgus malalignment on the tibial component under stance-phase gait cycle loading conditions. Validated finite element models for varus and valgus malalignment by 3° and 5° were developed to evaluate the effect of malalignment on the tibial component in TKA. Maximum contact stress and contact area on a polyethylene insert, maximum contact stress on patellar button and the collateral ligament force were investigated.Objectives
Methods
The primary purpose of this study of metal-on-metal
(MoM) hip resurfacing was to compare the effect of using a cementless
or cemented femoral component on the subsequent bone mineral density
(BMD) of the femoral neck. This was a single-centre, prospective, double-blinded control
trial which randomised 120 patients (105 men and 15 women) with
a mean age of 49.4 years (21 to 68) to receive either a cemented
or cementless femoral component. Follow-up was to two years. Outcome
measures included total and six-point region-of-interest BMD of
the femoral neck, radiological measurements of acetabular inclination,
neck-shaft and stem-shaft angles, and functional outcome scores
including the Harris hip score, the Western Ontario and McMaster
Universities Osteoarthritis Index and the University of California
at Los Angeles activity scale. In total, 17 patients were lost to follow-up leaving 103 patients
at two years. There were no revisions in the cementless group and
three revisions (5%) in the cemented group (two because of hip pain
and one for pseudotumour). The total BMD was significantly higher in the cementless group
at six months (p <
0.001) and one year (p = 0.01) than in the
cemented group, although there was a loss of statistical significance
in the difference at two years (p = 0.155). All patient outcomes improved significantly: there were no significant
differences between the two groups. The results show better preservation of femoral neck BMD with
a cementless femoral component after two years of follow-up. Further
investigation is needed to establish whether this translates into
improved survivorship. Cite this article:
Tantalum (Ta) trabecular metal components are increasingly used
to reconstruct major bone defects in revision arthroplasty surgery.
It is known that some metals such as silver have antibacterial properties.
Recent reports have raised the question regarding whether Ta components
are protective against infection in revision surgery. This laboratory
study aimed to establish whether Ta has intrinsic antibacterial
properties against planktonic bacteria, or the ability to inhibit
biofilm formation. Equal-sized pieces of Ta and titanium (Ti) acetabular components
were sterilised and incubated with a low dose inoculum of either Aims
Materials and Methods
We describe the use of a protocol of irrigation and debridement
(I&
D) with retention of the implant for the treatment of periprosthetic
infection of a total elbow arthroplasty (TEA). This may be an attractive
alternative to staged re-implantation. Between 1990 and 2010, 23 consecutive patients were treated in
this way. Three were lost to follow-up leaving 20 patients (21 TEAs)
in the study. There were six men and 14 women. Their mean age was
58 years (23 to 76). The protocol involved: component unlinking,
irrigation and debridement (I&
D), and the introduction of antibiotic
laden cement beads; organism-specific intravenous antibiotics; repeat
I&
D and re-linkage of the implant if appropriate; long-term
oral antibiotic therapy. Aims
Patients and Methods
We aimed to assess the comparability of data in joint replacement
registries and identify ways of improving the comparisons between
registries and the overall monitoring of joint replacement surgery. We conducted a review of registries that are full members of
the International Society of Arthroplasty Registries with publicly
available annual reports in English. Of the six registries which
were included, we compared the reporting of: mean age, definitions
for revision and re-operation, reasons for revision, the approach
to analysing revisions, and patient-reported outcome measures (PROMs)
for primary and revision total hip arthroplasty (THA) and hip resurfacing
arthroplasty (HRA).Aims
Materials 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 anterior pelvic internal fixator is increasingly used for
the treatment of unstable, or displaced, injuries of the anterior
pelvic ring. The evidence for its use, however, is limited. The
aim of this paper is to describe the indications for its use, how
it is applied and its complications. We reviewed the case notes and radiographs of 50 patients treated
with an anterior pelvic internal fixator between April 2010 and
December 2015 at a major trauma centre in the United Kingdom. The
median follow-up time was 38 months (interquartile range 24 to 51).Aims
Patients and Methods
Fretting and corrosion at the modular head/neck junction, known
as trunnionosis, in total hip arthroplasty (THA) is a cause of adverse
reaction to metal debris (ARMD). We describe the outcome of revision
of metal-on-polyethylene (MoP) THA for ARMD due to trunnionosis
with emphasis on the risk of major complications. A total of 36 patients with a MoP THA who underwent revision
for ARMD due to trunnionosis were identified. Three were excluded
as their revision had been to another metal head. The remaining
33 were revised to a ceramic head with a titanium sleeve. We describe
the presentation, revision findings, and risk of complications in
these patients.Aims
Patients and Methods