Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single prosthesis design (Anatomic Dual Mobility (ADM) Stryker, Mahwah, New Jersey). Patient medical records and radiographs were reviewed to confirm the type of implant used, to identify any preoperative risk factors for dislocation, and any complications. Radiographic analysis was performed to assess for signs of osteolysis or remodelling of the acetabulum.Aims
Materials and Methods
The aim of this study was to determine the polyethylene wear rate of Phase 3 Oxford Unicompartmental Knee Replacement bearings and to investigate the effects of resin type and manufacturing process. A total of 63 patients with at least ten years’ follow-up with three bearing types (1900 resin machined, 1050 resin machined, and 1050 resin moulded) were recruited. Patients underwent full weight-bearing model-based radiostereometric analysis to determine the bearing thickness. The linear wear rate was estimated from the change in thickness divided by the duration of implantation.Objectives
Methods
Our aim in this study was to describe a continuing review of
11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral
heads on a Charnley flanged femoral component, articulating against
a silane crosslinked polyethylene. Nine patients (11 THAs) were reviewed at a mean of 27.5 years
(26 to 28) post-operatively. Outcome was assessed using the d’Aubigne
and Postel, and Charnley scores and penetration was recorded on
radiographs. In addition, the oxidation of a 29-year-old shelf-aged
acetabular component was analysed.Aims
Patients and Methods
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:
Our primary aim was to describe migration of the Exeter stem with a 32 mm head on highly crosslinked polyethylene and whether this is influenced by age. Our secondary aims were to assess functional outcome, satisfaction, activity, and bone mineral density (BMD) according to age. A prospective cohort study was conducted. Patients were recruited into three age groups: less than 65 years (n = 65), 65 to 74 years (n = 68), and 75 years and older (n = 67). There were 200 patients enrolled in the study, of whom 115 were female and 85 were male, with a mean age of 69.9 years (sd 9.5, 42 to 92). They were assessed preoperatively, and at three, 12 and, 24 months postoperatively. Stem migration was assessed using Einzel-Bild-Röntgen-Analyse (EBRA). Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score (HHS), Hip Disability and Osteoarthritis Outcome Score (HOOS), EuroQol-5 domains questionnaire (EQ-5D), short form-36 questionnaire (SF-36,) and patient satisfaction were used to assess outcome. The Lower Extremity Activity Scale (LEAS), Timed Up and Go (TUG) test, and activPAL monitor (energy expelled, time lying/standing/walking and step count) were used to assess activity. The BMD was assessed in Gruen and Charnley zones.Objectives
Patients and Methods
We sought to establish whether an oxidised zirconium (OxZr) femoral
component causes less loss of polyethylene volume than a cobalt
alloy (CoCr) femoral component in total knee arthroplasty. A total of 20 retrieved tibial inserts that had articulated with
OxZr components were matched with 20 inserts from CoCr articulations
for patient age, body mass index, length of implantation, and revision
diagnosis. Changes in dimensions of the articular surfaces were compared
with those of pristine inserts using laser scanning. The differences
in volume between the retrieved and pristine surfaces of the two
groups were calculated and compared.Aims
Materials and Methods
Advances in polyethylene (PE) in total hip arthroplasty
have led to interest and increased use of highly crosslinked PE
(HXLPE) in total knee arthroplasty (TKA). Biomechanical data suggest
improved wear characteristics for HXLPE inserts over conventional
PE in TKA. Short-term results from registry data and few clinical
trials are promising. Our aim is to present a review of the history
of HXLPEs, the use of HXLPE inserts in TKA, concerns regarding potential mechanical
complications, and a thorough review of the available biomechanical
and clinical data. Cite this article:
The aim of this study was to determine whether there is a difference
in the rate of wear between acetabular components positioned within
and outside the ‘safe zones’ of anteversion and inclination angle. We reviewed 100 hips in 94 patients who had undergone primary
total hip arthroplasty (THA) at least ten years previously. Patients
all had the same type of acetabular component with a bearing couple
which consisted of a 28 mm cobalt-chromium head on a highly crosslinked
polyethylene (HXLPE) liner. A supine radiostereometric analysis
(RSA) examination was carried out which acquired anteroposterior
(AP) and lateral paired images. Acetabular component anteversion
and inclination angles were measured as well as total femoral head
penetration, which was divided by the length of implantation to
determine the rate of polyethylene wear.Aims
Patients and Methods
For this retrospective cohort study, patients aged ≤ 30 years
(very young) who underwent total hip arthroplasty (THA) were compared
with patients aged ≥ 60 years (elderly) to evaluate the rate of
revision arthroplasty, implant survival, the indications for revision,
the complications, and the patient-reported outcomes. We retrospectively reviewed all patients who underwent primary
THA between January 2000 and May 2015 from our institutional database.
A total of 145 very young and 1359 elderly patients were reviewed.
The mean follow-up was 5.3 years (1 to 18). Logistic generalized
estimating equations were used to compare characteristics and the revision
rate. Survival was evaluated using Kaplan–Meier curves and hazard
rates were created using Cox regression.Aims
Patients and Methods
The use of large-diameter metal-on-metal (MoM)
components in total hip arthroplasty (THA) is associated with an increased
risk of early failure due to adverse local tissue reaction to metal
debris (ARMD) in response to the release of metal ions from the
bearing couple and/or head-neck taper corrosion. The aim of this
paper was to present a review of the incidence and natural history
of ARMD and the forms of treatment, with a focus on the need for
and extent of resection or debulking of the pseudotumour. An illustrative
case report is presented of a patient with an intra-pelvic pseudotumour
associated with a large diameter MoM THA, which was treated successfully
with revision of the bearing surface to a dual mobility couple and
retention of the well-fixed acetabular and femoral components. The
pseudotumour was left Cite this article:
To present a surgically relevant update of trunnionosis. Systematic review performed April 2017.Aims
Materials and Methods
The leading indication for revision total hip
arthroplasty (THA) remains aseptic loosening owing to wear. The younger,
more active patients currently undergoing THA present unprecedented
demands on the bearings. Ceramic-on-ceramic (CoC) bearings have
consistently shown the lowest rates of wear. The recent advances,
especially involving alumina/zirconia composite ceramic, have led
to substantial improvements and good results Alumina/zirconia composite ceramics are extremely hard, scratch
resistant and biocompatible. They offer a low co-efficient of friction
and superior lubrication and lower rates of wear compared with other
bearings. The major disadvantage is the risk of fracture of the
ceramic. The new composite ceramic has reduced the risk of fracture
of the femoral head to 0.002%. The risk of fracture of the liner
is slightly higher (0.02%). Assuming that the components are introduced without impingement,
CoC bearings have major advantages over other bearings. Owing to
the superior hardness, they produce less third body wear and are
less vulnerable to intra-operative damage. The improved tribology means that CoC bearings are an excellent
choice for young, active patients requiring THA. Cite this article:
There is widespread concern regarding the incidence of adverse soft-tissue reactions after metal-on-metal (MoM) hip replacement. Recent National Joint Registry data have shown clear differences in the rates of failure of different designs of hip resurfacing. Our aim was to update the failure rates related to metal debris for the Articular Surface Replacement (ASR). A total of 505 of these were implanted. Kaplan-Meier analysis showed a failure rate of 25% at six years for the ASR resurfacing and of 48.8% for the ASR total hip replacement (THR). Of 257 patients with a minimum follow-up of two years, 67 (26.1%) had a serum cobalt concentration which was greater than 7 μg/l. Co-ordinate measuring machine analysis of revised components showed that all patients suffering adverse tissue reactions in the resurfacing group had abnormal wear of the bearing surfaces. Six THR patients had relatively low rates of articular wear, but were found to have considerable damage at the trunion-taper interface. Our results suggest that wear at the modular junction is an important factor in the development of adverse tissue reactions after implantation of a large-diameter MoM THR.
Large femoral heads have been used with increasing
frequency over the last decade. The prime reason is likely the effect
of large heads on stability. The larger head neck ratio, combined
with the increased jump distance of larger heads result in a greater
arc of impingement free motion, and greater resistance to dislocation
in a provocative position. Multiple studies have demonstrated clear
clinical efficacy in diminishing dislocation rates with the use
of large femoral heads. With crosslinked polyethylene, wear has
been shown to be equivalent between larger and smaller heads. However,
the stability advantages of increasing diameter beyond 38 mm have
not been clearly demonstrated. More importantly, recent data implicates
large heads in the increasing prevalence of groin pain and psoas impingement.
There are clear benefits with larger femoral head diameters, but
the advantages of diameters beyond 38 mm have not yet been demonstrated
clinically.
We studied prospectively the long-term results of the Charnley Elite-Plus femoral stem in 184 consecutive young patients (194 hips). There were 130 men and 54 women with a mean age of 49.1 years (21 to 60). The predominant diagnosis was osteonecrosis of the femoral head (63.6%, 117 patients). Clinical and radiological evaluation was undertaken at each follow-up. The mean follow-up was 11.2 years (10 to 12). The mean pre-operative Harris hip score was 43.4 (12 to 49) which improved to 91 (59 to 100) at the final follow-up. The survival of the femoral stem at 12 years was 99% with revision as the end-point. The mean annual linear wear of the polyethylene liner was 0.17 mm (0.13 to 0.22). The prevalence of acetabular osteolysis was 10.8% (21 hips) and osteolysis of the calcar femorale 12.9% (25 hips). A third-generation cementing technique, accurate alignment of the stem and the use of a 22 mm zirconia head were important factors in the prevention of aseptic loosening of the Elite Plus femoral stem in these high-risk young patients.
The aim of this systematic review was to report the rate of dislocation
following the use of dual mobility (DM) acetabular components in
primary and revision total hip arthroplasty (THA). A systematic review of the literature according to the Preferred
Reporting Items for Systematic Reviews and Meta-analyses guidelines
was performed. A comprehensive search of Pubmed/Medline, Cochrane
Library and Embase (Scopus) was conducted for English articles between
January 1974 and March 2016 using various combinations of the keywords “dual
mobility”, “dual-mobility”, “tripolar”, “double-mobility”, “double
mobility”, “hip”, “cup”, “socket”. The following data were extracted
by two investigators independently: demographics, whether the operation
was a primary or revision THA, length of follow-up, the design of
the components, diameter of the femoral head, and type of fixation
of the acetabular component.Aims
Materials and Methods
Despite a lack of long-term follow-up, there
is an increasing trend towards using femoral heads of large diameter
in total hip replacement (THR), partly because of the perceived
advantage of lower rates of dislocation. However, increasing the
size of the femoral head is not the only way to reduce the rate
of dislocation; optimal alignment of the components and repair of
the posterior capsule could achieve a similar effect. In this prospective study of 512 cemented unilateral THRs (Male:Female
230:282) performed between 2004 and 2011, we aimed to determine
the rate of dislocation in patients who received a 22 mm head on
a 9/10 Morse taper through a posterior approach with capsular repair
and using the transverse acetabular ligament (TAL) as a guide for the
alignment of the acetabular component. The mean age of the patients
at operation was 67 years (35 to 89). The mean follow-up was 2.8
years (0.5 to 6.6). Pre- and post-operative assessment included
Oxford hip, Short Form-12 and modified University of California
Los Angeles and Merle D’Aubigne scores. The angles of inclination
and anteversion of the acetabular components were measured using
radiological software. There were four dislocations (0.78%), all
of which were anterior. In conclusion, THR with a 22 mm diameter head performed through
a posterior approach with capsular repair and using the TAL as a
guide for the alignment of the acetabular component was associated
with a low rate of dislocation. Cite this article:
One goal of total hip arthroplasty is to restore normal hip anatomy.
The aim of this study was to compare displacement of the centre
of rotation (COR) using a standard reaming technique with a technique
in which the acetabulum was reamed immediately peripherally and
referenced off the rim. In the first cohort the acetabulum was reamed to the floor followed
by sequentially larger reamers. In the second cohort the acetabulum
was only reamed peripherally, starting with a reamer the same size
as the native femoral head. Anteroposterior pelvic radiographs were
analysed for acetabular floor depth and vertical and horizontal position
of the COR.Aims
Patients and Methods
