The purpose of this retrospective study was to evaluate the minimum
five-year outcome of revision total hip arthroplasty (THA) using
the Kerboull acetabular reinforcement device (KARD) in patients
with Paprosky type III acetabular defects and destruction of the
inferior margin of the acetabulum. We identified 36 patients (37 hips) who underwent revision THA
under these circumstances using the KARD, fresh frozen allograft
femoral heads, and reconstruction of the inferior margin of the
acetabulum. The Merle d’Aubigné system was used for clinical assessment.
Serial anteroposterior pelvic radiographs were used to assess migration
of the acetabular component.Aims
Patients and Methods
The treatment of bone loss in revision total
knee arthroplasty has evolved over the past decade. While the management
of small to moderate sized defects has demonstrated good results
with a variety of traditional techniques (cement and screws, small
metal augments, impaction bone grafting or modular stems), the treatment of
severe defects continues to be problematic. The use of a structural
allograft has declined in recent years due to an increased failure
rate with long-term follow-up and with the introduction of highly
porous metal augments that emphasise biological metaphyseal fixation.
Recently published mid-term results on the use of tantalum cones
in patients with severe bone loss has reaffirmed the success of
this treatment strategy. Cite this article:
Our aim was to evaluate the radiographic characteristics of patients
undergoing total hip arthroplasty (THA) for the potential of posterior
bony impingement using CT simulations. Virtual CT data from 112 patients who underwent THA were analysed.
There were 40 men and 72 women. Their mean age was 59.1 years (41
to 76). Associations between radiographic characteristics and posterior
bony impingement and the range of external rotation of the hip were
evaluated. In addition, we investigated the effects of pelvic tilt
and the neck/shaft angle and femoral offset on posterior bony impingement.Aims
Patients and Methods
The purpose of this study was to compare the long-term results
of primary total hip arthroplasty (THA) in young patients using
either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene
liner in terms of functional outcome, incidence of osteolysis, radiological
wear and rate of revision. We included all patients between the ages of 45 and 65 years
who, between January 2000 and December 2001, had undergone a primary
THA for osteoarthritis at our hospital using a CPE or HXLPE acetabular
liner and a 28 mm cobalt-chrome femoral head. From a total of 160 patients, 158 (177 hips) were available for
review (CPE 89; XLPE 88). The mean age, body mass index (BMI) and
follow-up in each group were: CPE: 56.8 years (46 to 65); 30.7 kg/m2 (19
to 58); 13.2 years (2.1 to 14.7) and HXLPE: 55.6 years (45 to 65);
BMI: 30 kg/m2 (18 to 51); 13.1 years (5.7 to 14.4).Aims
Methods
To evaluate the outcomes of cemented total hip arthroplasty (THA)
following a fracture of the acetabulum, with evaluation of risk
factors and comparison with a patient group with no history of fracture. Between 1992 and 2016, 49 patients (33 male) with mean age of
57 years (25 to 87) underwent cemented THA at a mean of 6.5 years
(0.1 to 25) following acetabular fracture. A total of 38 had undergone
surgical fixation and 11 had been treated non-operatively; 13 patients
died at a mean of 10.2 years after THA (0.6 to 19). Patients were
assessed pre-operatively, at one year and at final follow-up (mean
9.1 years, 0.5 to 23) using the Oxford Hip Score (OHS). Implant
survivorship was assessed. An age and gender-matched cohort of THAs
performed for non-traumatic osteoarthritis (OA) or avascular necrosis
(AVN) (n = 98) were used to compare complications and patient-reported outcome
measures (PROMs).Aims
Patients and Methods
One method of femoral head preservation following avascular necrosis
(AVN) is core decompression and insertion of a tantalum rod. However,
there may be a high failure rate associated with this procedure.
The purpose of this study was to document the clinical and radiological
outcomes following total hip arthroplasty (THA) subsequent to failed
tantalum rod insertion. A total of 37 failed tantalum rods requiring total hip arthroplasty
were identified from a prospective database. There were 21 hips
in 21 patients (12 men and nine women, mean age 37 years, 18 to
53) meeting minimum two year clinical and radiographic follow-up
whose THAs were carried out between November 2002 and April 2013
(mean time between tantalum rod implantation and conversion to a
THA was 26 months, 6 to 72). These were matched by age and gender
to individuals (12 men, nine women, mean age 40 years, 18 to 58)
receiving THA for AVN without prior tantalum rod insertion.Aims
Patients and Methods
We describe our technique and rationale using
hybrid fixation for primary total hip arthroplasty (THA) at the Hospital
for Special Surgery. Modern uncemented acetabular components have
few screw holes, or no holes, polished inner surfaces, improved
locking mechanisms, and maximised thickness and shell-liner conformity. Uncemented
sockets can be combined with highly cross-linked polyethylene liners,
which have demonstrated very low wear and osteolysis rates after
ten to 15 years of implantation. The results of cement fixation
with a smooth or polished surface finished stem have been excellent,
virtually eliminating complications seen with cementless fixation
like peri-operative femoral fractures and thigh pain. Although mid-term
results of modern cementless stems are encouraging, the long-term
data do not show reduced revision rates for cementless stems compared
with cemented smooth stems. In this paper we review the conduct
of a hybrid THA, with emphasis on pre-operative planning, surgical
technique, hypotensive epidural anaesthesia, and intra-operative
physiology. Cite this article:
In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year.Objectives
Patients and Methods
Lumbar fusion is known to reduce the variation in pelvic tilt
between standing and sitting. A flexible lumbo-pelvic unit increases
the stability of total hip arthroplasty (THA) when seated by increasing
anterior clearance and acetabular anteversion, thereby preventing
impingement of the prosthesis. Lumbar fusion may eliminate this protective
pelvic movement. The effect of lumbar fusion on the stability of
total hip arthroplasty has not previously been investigated. The Medicare database was searched for patients who had undergone
THA and spinal fusion between 2005 and 2012. PearlDiver software
was used to query the database by the International Classification
of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedural
code for primary THA and lumbar spinal fusion. Patients who had
undergone both lumbar fusion and THA were then divided into three
groups: 1 to 2 levels, 3 to 7 levels and 8+ levels of fusion. The
rate of dislocation in each group was established using ICD-9-CM codes.
Patients who underwent THA without spinal fusion were used as a
control group. Statistical significant difference between groups
was tested using the chi-squared test, and significance set at p
<
0.05.Aims
Patients and Methods
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
The use of ceramic femoral heads in total hip arthroplasty (THA) has increased due to their proven low bearing wear characteristics. Ceramic femoral heads are also thought to reduce wear and corrosion at the head-stem junction with titanium (Ti) stems when compared with metal heads. We sought to evaluate taper damage of ceramic compared with metal heads when paired with cobalt chromium (CoCr) alloy stems in a single stem design. This retrieval study involved 48 total hip arthroplasties (THAs) with CoCr V40 trunnions paired with either CoCr (n = 21) or ceramic (n = 27) heads. The taper junction of all hips was evaluated for fretting/corrosion damage and volumetric material loss using a roundness-measuring machine. We used linear regression analysis to investigate taper damage differences after adjusting for potential confounding variables.Objectives
Methods
The purpose of this study was to evaluate whether an innovative
templating technique could predict the need for acetabular augmentation
during primary total hip arthroplasty for patients with dysplastic
hips. We developed a simple templating technique to estimate acetabular
component coverage at total hip arthroplasty, the True Cup: False
Cup (TC:FC) ratio. We reviewed all patients with dysplastic hips
who underwent primary total hip arthroplasty between 2005 and 2012.
Traditional radiological methods of assessing the degree of acetabular dysplasia
(Sharp’s angle, Tönnis angle, centre-edge angle) as well as the
TC:FC ratio were measured from the pre-operative radiographs. A
comparison of augmented and non-augmented hips was undertaken to
determine any difference in pre-operative radiological indices between
the two cohorts. The intra- and inter-observer reliability for all
radiological indices used in the study were also calculated.Aims
Patients and Methods
To evaluate the hypothesis that failed osteosynthesis of periprosthetic
Vancouver type B1 fractures can be treated successfully with stem
revision using a transfemoral approach and a cementless, modular,
tapered revision stem with reproducible rates of fracture healing,
stability of the revision stem, and clinically good results. A total of 14 patients (11 women, three men) with a mean age
of 72.4 years (65 to 90) undergoing revision hip arthroplasty after
failed osteosynthesis of periprosthetic fractures of Vancouver type
B1 were treated using a transfemoral approach to remove the well-fixed
stem before insertion of a modular, fluted titanium stem which obtained
distal fixation. These patients were clinically and radiologically
followed up for a mean 52.2 months (24 to 144).Aims
Patients and 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
This study aimed to determine the diagnostic performance of radiographic
criteria to detect aseptic acetabular loosening after revision total
hip arthroplasty (THA). Secondary aims were to determine the predictive
values of different thresholds of migration and to determine the
predictive values of radiolucency criteria. Acetabular component migration to re-revision was measured retrospectively
using Ein-Bild-Rontgen-Analyse (EBRA-Cup) and manual measurements
(Sutherland method) in two groups: Group A, 52 components (48 patients) found
not loose at re-revision and Group B, 42 components (36 patients)
found loose at re-revision between 1980 and 2015. The presence and
extent of radiolucent lines was also assessed.Aims
Patients and Methods
Advocates of debridement, antibiotics and implant retention (DAIR)
in hip periprosthetic joint infection (PJI) argue that a procedure
not disturbing a sound prosthesis-bone interface is likely to lead
to better survival and functional outcome compared with revision.
This case-control study aims were to compare outcome of DAIRs for
infected primary total hip arthroplasty (THA) with outcomes following
primary THA and two-stage revision of infected primary THAs. We retrospectively reviewed all DAIRs, performed for confirmed
infected primary hip arthropasty (n = 82) at out institution, between
1997 and 2013. Data recorded included full patient information and
type of surgery. Outcome measures included complications, mortality,
implant survivorship and functional outcome. Outcome was compared with
two control groups matched for gender and age; a cohort of primary
THAs (n = 120) and a cohort of two-stage revisions for infection
(n = 66).Aims
Patients and Methods
Our first aim was to determine whether there are significant
changes in the level of metal ions in the blood at mid-term follow-up,
in patients with an Articular Surface Replacement (ASR) arthroplasty.
Secondly, we sought to identify risk factors for any increases. The study involved 435 patients who underwent unilateral, metal-on-metal
(MoM) hip resurfacing (HRA) or total hip arthroplasty (THA). These
patients all had one measurement of the level of metal ions in the
blood before seven years had passed post-operatively (early evaluation)
and one after seven years had passed post-operatively (mid-term evaluation).
Changes in ion levels were tested using a Wilcoxon signed-rank test.
We identified subgroups at the highest risk of increase using a
multivariable linear logistic regression model.Aims
Patients and Methods
Aims. The aim of this study was to compare early functional and health
related quality of life outcomes (HRQoL) in patients who have undergone
total hip arthroplasty (THA) using a bone conserving short stem
femoral component and those in whom a conventional length uncemented
component was used. Outcome was assessed using a validated performance
based outcome instrument as well as patient reported outcome measures
(PROMs). Patients and Methods. We prospectively analysed 33 patients whose THA involved a contemporary
proximally porous coated tapered short
