Aims. To determine ten-year failure rates following 36 mm metal-on-metal
(MoM)
Aims. 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. Patients and Methods. Data from the National Joint Registry for England and Wales included
36 mm MoM THAs with
Aims. Our aim was to report survivorship data and lessons learned with
the Corail/
There is little evidence on the cost effectiveness
of different brands of hip prostheses. We compared lifetime cost effectiveness
of frequently used brands within types of prosthesis including cemented
(Exeter V40 Contemporary, Exeter V40 Duration and Exeter V40 Elite
Plus Ogee), cementless (Corail
We conducted a retrospective study to assess
the prevalence of adverse reactions to metal debris (ARMD) in patients
operated on at our institution with metal-on-metal (MoM) total hip
replacements with 36 mm heads using a
The popularity of cementless total hip replacement
(THR) has surpassed cemented THR in England and Wales. This retrospective
cohort study records survival time to revision following primary
cementless THR with the most common combination (accounting for
almost a third of all cementless THRs), and explores risk factors independently
associated with failure, using data from the National Joint Registry
for England and Wales. Patients with osteoarthritis who had a DePuy
Corail/
This study aims to assess the relationship between history of pseudotumour formation secondary to metal-on-metal (MoM) implants and periprosthetic joint infection (PJI) rate, as well as establish ESR and CRP thresholds that are suggestive of infection in these patients. We hypothesized that patients with a pseudotumour were at increased risk of infection. A total of 1,171 total hip arthroplasty (THA) patients with MoM articulations from August 2000 to March 2014 were retrospectively identified. Of those, 328 patients underwent metal artefact reduction sequence MRI and had minimum two years’ clinical follow-up, and met our inclusion criteria. Data collected included demographic details, surgical indication, laterality, implants used, history of pseudotumour, and their corresponding preoperative ESR (mm/hr) and CRP (mg/dl) levels. Multivariate logistic regression modelling was used to evaluate PJI and history of pseudotumour, and receiver operating characteristic curves were created to assess the diagnostic capabilities of ESR and CRP to determine the presence of infection in patients undergoing revision surgery.Aims
Methods
Dislocation is a major concern following total hip arthroplasty (THA) for osteoarthritis (OA). Both dual-mobility components and standard acetabular components with large femoral heads are used to reduce the risk of dislocation. We investigated whether dual-mobility components are superior to standard components in reducing the two-year dislocation and revision risk in a propensity-matched sample from the Danish Hip Arthroplasty Register (DHR). This population-based cohort study analyzed data from the DHR and the Danish National Patient Register. We included all patients undergoing primary THA for OA from January 2010 to December 2019 with either dual-mobility or standard acetabular components with metal-on-polyethylene or ceramic-on-polyethylene articulations with a 36 mm femoral head. The samples were propensity score-matched on patient and implant characteristics. The primary outcome was the difference in the absolute risk of dislocation within two years, with a secondary outcome of the difference in the absolute risk of revision surgery of any cause within the same timeframe. The cumulative incidence of dislocation was calculated using the Aalen-Johansen estimator, while the difference in absolute risk was estimated using absolute risk regression (ARR).Aims
Methods
Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis. We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).Aims
Methods
Conventional patient-reported surveys, used for patients undergoing total hip arthroplasty (THA), are limited by subjectivity and recall bias. Objective functional evaluation, such as gait analysis, to delineate a patient’s functional capacity and customize surgical interventions, may address these shortcomings. This systematic review endeavours to investigate the application of objective functional assessments in appraising individuals undergoing THA. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied. Eligible studies of THA patients that conducted at least one type of objective functional assessment both pre- and postoperatively were identified through Embase, Medline/PubMed, and Cochrane Central database-searching from inception to 15 September 2023. The assessments included were subgrouped for analysis: gait analysis, motion analysis, wearables, and strength tests.Aims
Methods
The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components. Patients were randomized to receive one of the two femoral components (Avenir or Corail) during their primary total hip arthroplasty between August 2018 and September 2020. Radiostereometric analysis examinations at six, 12, and 24 months were used to assess the migration of each implanted femoral component compared to a baseline assessment. Patient-reported outcome measures were also recorded for these same timepoints. Overall, 50 patients were enrolled (62% male (n = 31), with a mean age of 65.7 years (SD 7.3), and mean BMI of 30.2 kg/m2 (SD 5.2)).Aims
Methods
The benefit of a dual-mobility acetabular component (DMC) for primary total hip arthroplasties (THAs) is controversial. This study aimed to compare the dislocation and complication rates when using a DMC compared to single-mobility (SM) acetabular component in primary elective THA using data collected at a single centre, and compare the revision rates and survival outcomes in these two groups. Between 2010 and 2019, 2,075 primary THAs using either a cementless DM or SM acetabular component were included. Indications for DMC were patients aged older than 70 years or with high risk of dislocation. All other patients received a SM acetabular component. Exclusion criteria were cemented implants, patients treated for femoral neck fracture, and follow-up of less than one year. In total, 1,940 THAs were analyzed: 1,149 DMC (59.2%) and 791 SM (40.8%). The mean age was 73 years (SD 9.2) in the DMC group and 57 years (SD 12) in the SM group. Complications and revisions have been analyzed retrospectively.Aims
Methods
It is not known whether preservation of the capsule of the hip positively affects patient-reported outcome measures (PROMs) in total hip arthroplasty using the direct anterior approach (DAA-THA). A recent randomized controlled trial found no clinically significant difference at one year postoperatively. This study aimed to determine whether preservation of the anterolateral capsule and anatomical closure improve the outcome and revision rate, when compared with resection of the anterolateral capsule, at two years postoperatively. Two consecutive groups of patients whose operations were performed by the senior author were compared. The anterolateral capsule was resected in the first group of 430 patients between January 2012 and December 2014, and preserved and anatomically closed in the second group of 450 patients between July 2015 and December 2017. There were no other technical changes between the two groups. Patient characteristics, the Charlson Comorbidity Index (CCI), and surgical data were collected from our database. PROM questionnaires, consisting of the Oxford Hip Score (OHS) and Core Outcome Measures Index (COMI-Hip), were collected two years postoperatively. Data were analyzed with generalized multiple regression analysis.Aims
Methods
To find out if there is an inverse association between estimated glomerular filtration rate (eGFR) and whole blood cobalt (Co) and chromium (Cr) levels in patients with metal-on-metal (MoM) hip arthroplasties and renal insufficiency, suggesting that renal insufficiency could cause accumulation of Co and Cr in blood. Out of 2,520 patients with 3,013 MoM hip arthroplasties, we identified 1,244 patients with whole blood Co, Cr, and creatinine measured within no more than a one-year interval. We analyzed the correlation of blood metal ion levels and eGFR to identify a potential trend of accumulating Co or Cr with decreasing eGFR.Aims
Methods
This study aimed to use intraoperative free electromyography to examine how the placement of a retractor at different positions along the anterior acetabular wall may affect the femoral nerve during total hip arthroplasty (THA) when undertaken using the direct anterior approach (THA-DAA). Intraoperative free electromyography was performed during primary THA-DAA in 82 patients (94 hips). The highest position of the anterior acetabular wall was defined as the “12 o’clock” position (middle position) when the patient was in supine position. After exposure of the acetabulum, a retractor was sequentially placed at the ten, 11, 12, one, and two o’clock positions (right hip; from superior to inferior positions). Action potentials in the femoral nerve were monitored with each placement, and the incidence of positive reactions (defined as explosive, frequent, or continuous action potentials, indicating that the nerve was being compressed) were recorded as the primary outcome. Secondary outcomes included the incidence of positive reactions caused by removing the femoral head, and by placing a retractor during femoral exposure; and the incidence of femoral nerve palsy, as detected using manual testing of the strength of the quadriceps muscle.Aims
Methods
Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients. Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8).Aims
Methods
The aim of this study was to determine if uncemented acetabular polyethylene (PE) liner geometry, and lip size, influenced the risk of revision for instability or loosening. A total of 202,511 primary total hip arthroplasties (THAs) with uncemented acetabular components were identified from the National Joint Registry (NJR) dataset between 2003 and 2017. The effect of liner geometry on the risk of revision for instability or loosening was investigated using competing risk regression analyses adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, surgeon grade, surgical approach, head size, and polyethylene crosslinking. Stratified analyses by surgical approach were performed, including pairwise comparisons of liner geometries.Aims
Methods
The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach. Patients were randomized to either a collared (n = 23) or collarless (n = 26) cementless femoral stem implanted using the DA approach. Canal fill ratio (CFR) was measured on the first postoperative radiographs. Patients underwent a supine radiostereometric analysis (RSA) exam postoperatively on the day of surgery and at two, four, six, 12, 26, and 52 weeks postoperatively. Patient-reported outcome measures (Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the 12-item Short Form Health Survey Mental and Physical Score, and University of California, Los Angeles (UCLA) Activity Score) were measured preoperatively and at each post-surgery clinic visit. Activity and function were also measured as the weekly average step count recorded by an activity tracker, and an instrumented timed up-and-go (TUG) test in clinic, respectively.Aims
Methods
The aim of this retrospective audit was to determine the route of referral or presentation of patients requiring revision following primary total hip arthroplasty (THA). A total of 4802 patients were implanted with an Orthopaedic Data Evaluation Panel (ODEP) 10A* cementless implant (Corail/Pinnacle) between 2005 and 2015; 80 patients with a mean age of 67.8 years (Aims
Patients and Methods
We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice. Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed. Patients were invited to have their cobalt and chromium levels retested, and were provided an Oxford Hip Score. Serum ion levels were then compared between groups (28 mm, 36 mm, and 40 mm heads) and over time.Aims
Methods
The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival. We considered six cohorts that included a total of 1,707 primary hips done between 1982 and 2010. These included 223 conventional polyethylene sterilized with γ irradiation in air (CPE-GA), 114 conventional polyethylene sterilized with gas plasma (CPE-GP), 116 crosslinked polyethylene (XLPE), 1,083 metal-on-metal (MOM), 90 ceramic-on-ceramic (COC), and 81 surface arthroplasties (SAs). With the exception of the COC, all other groups used cobalt-chromium (CoCr) femoral heads. The mean follow-up was 10 (0.008 to 35) years. Descriptive statistics with revisions per 100 component years (re/100 yr) and survival analysis with revision for any reason as the endpoint were used to compare bearing surfaces.Aims
Methods
Cementless primary total hip arthroplasty (THA) is associated with risks of bleeding and thromboembolism. Anticoagulants are effective as venous thromboprophylaxis, but with an increased risk of bleeding. Tranexamic acid (TXA) is an efficient antifibrinolytic agent, but the mode and timing of its administration remain controversial. This study aimed to determine whether two intravenous (IV) TXA regimens (a three-hour two-dose (short-TXA) and 11-hour four-dose (long-TXA)) were more effective than placebo in reducing perioperative real blood loss (RBL, between baseline and day 3 postoperatively) in patients undergoing THA who receive rivaroxaban as thromboprophylaxis. The secondary aim was to assess the non-inferiority of the reduction of blood loss of the short protocol A multicentre, prospective, randomized, double-blind, placebo-controlled trial was undertaken involving 229 patients undergoing primary cementless THA using a posterior approach, whose extended rivaroxaban thromboprophylaxis started on the day of surgery. There were 98 male and 131 female patients, with a mean age of 65.5 years (32 to 91). The primary outcome, perioperative RBL, was evaluated at 72 hours postoperatively. The efficacy of short- and long-TXA protocols in the reduction of perioperative RBL was compared with a placebo group.Aims
Patients and Methods
This study aimed to explore whether intraoperative nerve monitoring can identify risk factors and reduce the incidence of nerve injury in patients with high-riding developmental dysplasia. We conducted a historical controlled study of patients with unilateral Crowe IV developmental dysplasia of the hip (DDH). Between October 2016 and October 2017, intraoperative nerve monitoring of the femoral and sciatic nerves was applied in total hip arthroplasty (THA). A neuromonitoring technician was employed to monitor nerve function and inform the surgeon of ongoing changes in a timely manner. Patients who did not have intraoperative nerve monitoring between September 2015 and October 2016 were selected as the control group. All the surgeries were performed by one surgeon. Demographics and clinical data were analyzed. A total of 35 patients in the monitoring group (ten male, 25 female; mean age 37.1 years (20 to 46)) and 56 patients in the control group (13 male, 43 female; mean age 37.9 years (23 to 52)) were enrolled. The mean follow-up of all patients was 13.1 months (10 to 15).Aims
Patients and Methods
To determine whether there is any association between glomerular
filtration rate (GFR) and blood cobalt (Co) and chromium (Cr) levels
in patients with metal-on-metal (MoM) hip arthroplasty. We identified 179 patients with a unilateral 36 mm diameter head
as part of a stemmed Summit-Pinnacle MoM hip arthroplasty. GFR was
calculated using the Modification of Diet in Renal Disease formula.Aims
Patients and Methods
We wished to investigate the influence of metal debris exposure
on the subsequent immune response and resulting soft-tissue injury
following metal-on-metal (MoM) hip arthroplasty. Some reports have
suggested that debris generated from the head-neck taper junction
is more destructive than equivalent doses from metal bearing surfaces. We investigated the influence of the source and volume of metal
debris on chromium (Cr) and cobalt (Co) concentrations in corresponding
blood and hip synovial fluid samples and the observed agglomerated
particle sizes in excised tissues using multiple regression analysis
of prospectively collected data. A total of 199 explanted MoM hips
(177 patients; 132 hips female) were analysed to determine rates
of volumetric wear at the bearing surfaces and taper junctions. Aims
Patients and Methods
We assessed the difference in hospital based and early clinical
outcomes between the direct anterior approach and the posterior
approach in patients who undergo total hip arthroplasty (THA). The outcome was assessed in 448 (203 males, 245 females) consecutive
patients undergoing unilateral primary THA after the implementation
of an ‘Enhanced Recovery’ pathway. In all, 265 patients (mean age:
71 years (49 to 89); 117 males and 148 females) had surgery using
the direct anterior approach (DAA) and 183 patients (mean age: 70
years (26 to 100); 86 males and 97 females) using a posterior approach.
The groups were compared for age, gender, American Society of Anesthesiologists
grade, body mass index, the side of the operation, pre-operative
Oxford Hip Score (OHS) and attendance at ‘Joint school’. Mean follow-up
was 18.1 months (one to 50).Aims
Patients and Methods
The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check. Intraoperative barcode registration of arthroplasty implants was introduced in Denmark in 2013. We developed a compatibility database and, from May 2017, real-time compatibility checking was implemented and became part of the registration. We defined four classes of component incompatibility: A-I, A-II, B-I, and B-II, depending on an assessment of the level of risk to the patient (A/B), and on whether incompatibility was knowingly accepted (I/II).Aims
Materials and Methods
The primary aim of this independent prospective randomised trial
was to compare serum metal ion levels for ceramic-on-metal (CoM)
and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty
(THA). Our one-year results demonstrated elevation in metal ion
levels above baseline with no significant difference between the
CoM and MoM groups. This paper reviews the five-year data. The implants used in each patient differed only in respect to
the type of femoral head (ceramic or metal). At five-year follow-up
of the 83 enrolled patients, data from 67 (36 CoM, 31 MoM) was available
for comparison.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
The aims of this study were to determine the clinical and radiographic
outcomes, implant survivorship, and complications of patients with
a history of poliomyelitis undergoing total hip arthroplasty (THA)
in affected limbs and unaffected limbs of this same population. A retrospective review identified 51 patients (27 male and 24
female, 59 hips) with a mean age of 66 years (38 to 88) and with
the history of poliomyelitis who underwent THA for degenerative
arthritis between 1970 and 2012. Immigrant status, clinical outcomes,
radiographic results, implant survival, and complications were recorded.Aims
Patients and Methods
The classical longitudinal incision used for the direct anterior
approach (DAA) to the hip does not follow the tension lines of the
skin and can lead to impaired wound healing and poor cosmesis. The
purpose of this retrospective study was to determine the satisfaction
with the scar, and functional and radiographic outcomes comparing
the classic longitudinal incision with a modified skin crease ‘bikini’
when the DAA is used for total hip arthroplasty (THA). A total of 964 patients (51% female; 59% longitudinal, 41% ‘bikini’)
completed a follow-up questionnaire between two and four years postoperatively,
including the Oxford Hip Score (OHS), the University of North Carolina
‘4P’ scar scale (UNC4P) and two items for assessing the aesthetic
appearance of the scar and symptoms of numbness. The positioning
of the components, rates of heterotopic ossification (HO) and rates
of revision were assessed.Aims
Patients and Methods
The Corail stem has good long-term results. After four years
of using this stem, we have detected a small group of patients who
have presented with symptomatic metaphyseal debonding. The aim of
this study was to quantify the incidence of this complication, to
delineate the characteristics of patients presenting with this complication
and to compare these patients with asymptomatic controls to determine
any important predisposing factors. Of 855 Corail collarless cementless stems implanted for osteoarthritis,
18 presented with symptomatic metaphyseal debonding. A control group
of 74 randomly selected patients was assembled. Clinical and radiological
parameters were measured and a logistic regression model was created
to evaluate factors associated with metaphyseal debonding.Aims
Patients and Methods
We sought to determine whether cobalt-chromium alloy (CoCr) femoral
stem tapers (trunnions) wear more than titanium (Ti) alloy stem
tapers (trunnions) when used in a large diameter (LD) metal-on-metal
(MoM) hip arthroplasty system. We performed explant analysis using validated methodology to
determine the volumetric material loss at the taper surfaces of
explanted LD CoCr MoM hip arthroplasties used with either a Ti alloy
(n = 28) or CoCr femoral stem (n = 21). Only 12/14 taper constructs
with a rough male taper surface and a nominal included angle close
to 5.666° were included. Multiple regression modelling was undertaken
using taper angle, taper roughness, bearing diameter (horizontal
lever arm) as independent variables. Material loss was mapped using
a coordinate measuring machine, profilometry and scanning electron
microscopy.Aims
Patients and 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
There is no consensus about the best method of achieving equal
leg lengths at total hip arthroplasty (THA) in patients with Crowe
type-IV developmental dysplasia of the hip (DDH). We reviewed our
experience of a consecutive series of patients who underwent THA
for this indication. We retrospectively reviewed 78 patients (86 THAs) with Crowe
type-IV DDH, including 64 women and 14 men, with a minimum follow-up
of two years. The mean age at the time of surgery was 52.2 years
(34 to 82). We subdivided Crowe type-IV DDH into two major types
according to the number of dislocated hips, and further categorised
them into three groups according to the occurrence of pelvic obliquity
or spinal curvature. Leg length discrepancy (LLD) and functional
scores were analysed.Aims
Patients and Methods
Ceramic-on-metal (CoM) is a relatively new bearing
combination for total hip arthroplasty (THA) with few reported outcomes.
A total of 287 CoM THAs were carried out in 271 patients (mean age
55.6 years (20 to 77), 150 THAs in female patients, 137 in male)
under the care of a single surgeon between October 2007 and October
2009. With the issues surrounding metal-on-metal bearings the decision
was taken to review these patients between March and November 2011,
at a mean follow-up of 34 months (23 to 45) and to record pain,
outcome scores, radiological analysis and blood ion levels. The
mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268
hips (95%) had mild/very mild/no pain, the mean angle of inclination
of the acetabular component was 44.8o (28o to
63o), 82 stems (29%) had evidence of radiolucent lines
of >
1 mm in at least one Gruen zone and the median levels of cobalt
and chromium ions in the blood were 0.83 μg/L (0.24 μg/L to 27.56 μg/L)
and 0.78 μg/L (0.21 μg/L to 8.84 μg/L), respectively. The five-year
survival rate is 96.9% (95% confidence interval 94.7% to 99%). Due to the presence of radiolucent lines and the higher than
expected levels of metal ions in the blood, we would not recommend
the use of CoM THA without further long-term follow-up. We plan
to monitor all these patients regularly. Cite this article:
We evaluated the short-term functional outcome and prevalence
of bearing-specific generation of audible noise in 301 patients
(336 hips) operated on with fourth generation (Delta) medium diameter
head, ceramic-on-ceramic (CoC) total hip arthroplasties (THAs). There were 191 female (63%) and 110 male patients (37%) with
a mean age of 61 years (29 to 78) and mean follow-up of 2.1 years
(1.3 to 3.4). Patients completed three questionnaires: Oxford Hip
Score (OHS), Research and Development 36-item health survey (RAND-36)
and a noise-specific symptom questionnaire. Plain radiographs were also
analysed. A total of three hips (0.9%) were revised. Aims
Patients and Methods
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
Surgeons have commonly used modular femoral heads and stems from
different manufacturers, although this is not recommended by orthopaedic
companies due to the different manufacturing processes. We compared the rate of corrosion and rate of wear at the trunnion/head
taper junction in two groups of retrieved hips; those with mixed
manufacturers (MM) and those from the same manufacturer (SM). We identified 151 retrieved hips with large-diameter cobalt-chromium
heads; 51 of two designs that had been paired with stems from different
manufacturers (MM) and 100 of seven designs paired with stems from
the same manufacturer (SM). We determined the severity of corrosion
with the Goldberg corrosion score and the volume of material loss
at the head/stem junction. We used multivariable statistical analysis
to determine if there was a significant difference between the two
groups. Aims
Materials and Methods
Despite the worldwide usage of the cemented Contemporary
acetabular component (Stryker), no published data are available
regarding its use in patients aged <
50 years. We undertook a
mid- to long-term follow-up study, including all consecutive patients
aged
<
50 years who underwent a primary total hip replacement using
the Contemporary acetabular component with the Exeter cemented stem
between January 1999 and January 2006. There were 152 hips in 126
patients, 61 men and 65 women, mean age at surgery 37.6 years (16
to 49 yrs). One patient was lost to follow-up. Mean clinical follow-up of all implants was 7.6 years (0.9 to
12.0). All clinical questionnaire scores, including Harris hip score,
Oxford hip score and several visual analogue scales, were found
to have improved. The eight year survivorship of all acetabular
components for the endpoints revision for any reason or revision
for aseptic loosening was 94.4% (95% confidence interval (CI) 89.2
to 97.2) and 96.4% (95% CI 91.6 to 98.5), respectively. Radiological follow-up
was complete for 146 implants. The eight year survival for the endpoint
radiological loosening was 93.1% (95% CI 86.2 to 96.6). Three surviving
implants were considered radiologically loose but were asymptomatic.
The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent
lines (n = 20, 13.9%) in the 144 surviving cups indicates a need
for continued observation in the second decade of follow-up in order
to observe their influence on long-term survival. The clinical and radiological data resulting in a ten-year survival
rate >
90% in young patients support the use of the Contemporary
acetabular component in this specific patient group. Cite this article:
The primary aim of this study was to investigate the effect of
an enhanced recovery program (ERP) on the short-term functional
outcome after total hip arthroplasty (THA). Secondary outcomes included
its effect on rates of dislocation and mortality. Data were gathered on 1161 patients undergoing primary THA which
included 611 patients treated with traditional rehabilitation and
550 treated with an ERP. Aims
Patients and Methods
We investigated changes in the axial alignment of the ipsilateral
hip and knee after total hip arthroplasty (THA). We reviewed 152 patients undergoing primary THA (163 hips; 22
hips in men, 141 hips in women) without a pre-operative flexion
contracture. The mean age was 64 years (30 to 88). The diagnosis
was osteoarthritis (OA) in 151 hips (primary in 18 hips, and secondary
to dysplasia in 133) and non-OA in 12 hips. A posterolateral approach
with repair of the external rotators was used in 134 hips and an
anterior approach in 29 hips. We measured changes in leg length
and offset on radiographs, and femoral anteversion, internal rotation
of the hip and lateral patellar tilt on CT scans, pre- and post-operatively. Aims
Patients and Methods
Plasma levels of cobalt and chromium ions and
Metal Artefact Reduction Sequence (MARS)-MRI scans were performed
on patients with 209 consecutive, unilateral, symptomatic metal-on-metal
(MoM) hip arthroplasties. There was wide variation in plasma cobalt
and chromium levels, and MARS-MRI scans were positive for adverse reaction
to metal debris (ARMD) in 84 hips (40%). There was a significant
difference in the median plasma cobalt and chromium levels between
those with positive and negative MARS-MRI scans (p <
0.001).
Compared with MARS-MRI as the potential reference standard for the
diagnosis of ARMD, the sensitivity of metal ion analysis for cobalt
or chromium with a cut-off of >
7 µg/l was 57%. The specificity was
65%, positive predictive value was 52% and the negative predictive
value was 69% in symptomatic patients. A lowered threshold of >
3.5 µg/l for cobalt and chromium ion levels improved the sensitivity
and negative predictive value to 86% and 74% but at the expense
of specificity (27%) and positive predictive value (44%). Metal ion analysis is not recommended as a sole indirect screening
test in the surveillance of symptomatic patients with a MoM arthroplasty.
The investigating clinicians should have a low threshold for obtaining
cross-sectional imaging in these patients, even in the presence
of low plasma metal ion levels.
Ceramic-on-ceramic bearings in hip replacement have low rates of wear and are increasingly being used in young adults. Our aim was to determine the incidence of audible phenomena or other bearing-related complications. We retrospectively analysed 250 ceramic-on-ceramic hip replacements in 224 patients which had been implanted between April 2000 and December 2007. The mean age of the patients at operation was 44 years (14 to 83) and all the operations were performed using the same surgical technique at a single centre. At a mean follow-up of 59 months (24 to 94), the mean Oxford hip score was 40.89 (11 to 48). There were six revisions, three of which were for impingement-related complications. No patient reported squeaking, but six described grinding or clicking, which was usually associated with deep flexion. No radiological evidence of osteolysis or migration of the components was observed in any hip. The early to mid-term results of contemporary ceramic-on-ceramic hip replacement show promising results with few concerns in terms of noise and squeaking. Positioning of the acetabular component remains critical in regard to the reduction of other impingement-related complications.
We compared the clinical and radiological outcomes
of two cementless femoral stems in the treatment of patients with
a Garden III or IV fracture of the femoral neck. A total of 70 patients At final follow-up there were no statistically significant differences
between the short anatomical and the conventional stems with regard
to the mean Harris hip score (85.7 (66 to 100) Our study demonstrated that despite the poor bone quality in
these elderly patients with a fracture of the femoral neck, osseo-integration
was obtained in all hips in both groups. However, the incidence
of thigh pain, pulmonary microemboli and peri-prosthetic fracture
was significantly higher in the conventional stem group than in
the short stem group.
Dysplasia of the hip, hypotonia, osteopenia,
ligamentous laxity, and mental retardation increase the complexity
of performing and managing patients with Down syndrome who require
total hip replacement (THR). We identified 14 patients (six males,
eight females, 21 hips) with Down syndrome and degenerative disease
of the hip who underwent THR, with a minimum follow-up of two years
from 1969 to 2009. In seven patients, bilateral THRs were performed
while the rest had unilateral THRs. The mean clinical follow-up
was 5.8 years (standard deviation ( Cite this article:
A high radiographic inclination angle (RI) contributes
to accelerated wear and has been associated with dislocation after
total hip arthroplasty (THA). With freehand positioning of the acetabular
component there is a lack of accuracy, with a trend towards a high
radiographic inclination angle. The aim of this study was to investigate
whether the use of a digital protractor to measure the operative
inclination angle (OI) could improve the positioning of the acetabular
component in relation to a ‘safe zone’. We measured the radiographic inclination angles of 200 consecutive
uncemented primary THAs. In the first 100 the component was introduced
freehand and in the second 100 a digital protractor was used to
measure the operative inclination angle. The mean difference between the operative and the radiographic
inclination angles
(∆RI–OI) in the second cohort was 12.3° (3.8° to 19.8°). There was
a strong correlation between the circumference of the hip and ∆RI–OI.
The number of RI outliers was significantly reduced in the protractor
group (p = 0.002). Adjusting the OI, using a digital protractor and taking into
account the circumference of the patient’s hip, improves the RI
significantly (p <
0.001) and does not require additional operating
time. Cite this article:
We compared the rate of revision for instability
after total hip replacement (THR) when lipped and non-lipped acetabular
liners were used. We hypothesised that the use of a lipped liner
in a modular uncemented acetabular component reduces the risk of
revision for instability after primary THR. Using data from the
New Zealand Joint Registry, we found that the use of a lipped liner
was associated with a significantly decreased rate of revision for instability
and for all other indications. Adjusting for the size of the femoral
head, the surgical approach and the age and gender of the patient,
this difference remained strongly significant (p <
0.001). We conclude that evidence from the New Zealand registry suggests
that the use of lipped liners with modular uncemented acetabular
components is associated with a decreased rate of revision for instability
after primary THR. Cite this article:
In a time of limited resources, the debate continues
over which types of hip prosthesis are clinically superior and more
cost-effective. Orthopaedic surgeons increasingly need robust economic
evidence to understand the full value of the operation, and to aid
decision making on the ‘package’ of procedures that are available
and to justify their practice beyond traditional clinical preference. In this paper we explore the current economic debate about the
merits of cemented and cementless total hip replacement, an issue
that continues to divide the orthopaedic community. Cite this article:
We undertook a retrospective cohort study to
determine clinical outcomes following the revision of metal-on-metal (MoM)
hip replacements for adverse reaction to metal debris (ARMD), and
to identify predictors of time to revision and outcomes following
revision. Between 1998 and 2012 a total of 64 MoM hips (mean age
at revision of 57.8 years; 46 (72%) female; 46 (72%) hip resurfacings
and 18 (28%) total hip replacements) were revised for ARMD at one specialist
centre. At a mean follow-up of 4.5 years (1.0 to 14.6) from revision
for ARMD there were 13 hips (20.3%) with post-operative complications
and eight (12.5%) requiring re-revision. The Kaplan–Meier five-year survival rate for ARMD revision was
87.9% (95% confidence interval 78.9 to 98.0; 19 hips at risk). Excluding
re-revisions, the median absolute Oxford hip score (OHS) following
ARMD revision using the percentage method (0% best outcome and 100%
worst outcome) was 18.8% (interquartile range (IQR) 7.8% to 48.3%),
which is equivalent to 39/48 (IQR 24.8/48 to 44.3/48) when using
the modified OHS. Histopathological response did not affect time
to revision for ARMD (p = 0.334) or the subsequent risk of re-revision
(p = 0.879). Similarly, the presence or absence of a contralateral
MoM hip bearing did not affect time to revision for ARMD (p = 0.066)
or the subsequent risk of re-revision (p = 0.178). Patients revised to MoM bearings had higher rates of re-revision
(five of 16 MoM hips re-revised; p = 0.046), but those not requiring
re-revision had good functional results (median absolute OHS 14.6%
or 41.0/48). Short-term morbidity following revision for ARMD was
comparable with previous reports. Caution should be exercised when choosing
bearing surfaces for ARMD revisions. Cite this article:
The National Institute for Health and Clinical
Excellence (NICE) guidelines from 2011 recommend the use of cemented
hemi-arthroplasty for appropriate patients with an intracapsular
hip fracture. In our institution all patients who were admitted
with an intracapsular hip fracture and were suitable for a hemi-arthroplasty
between April 2010 and July 2012 received an uncemented prosthesis
according to our established departmental routine practice. A retrospective
analysis of outcome was performed to establish whether the continued
use of an uncemented stem was justified. Patient, surgical and outcome
data were collected on the National Hip Fracture database. A total
of 306 patients received a Cathcart modular head on a Corail uncemented
stem as a hemi-arthroplasty. The mean age of the patients was 83.3
years ( Cite this article:
Orientation of the acetabular component influences
wear, range of movement and the incidence of dislocation after total
hip replacement (THR). During surgery, such orientation is often
referenced to the anterior pelvic plane (APP), but APP inclination
relative to the coronal plane (pelvic tilt) varies substantially
between individuals. In contrast, the change in pelvic tilt from
supine to standing (dPT) is small for nearly all individuals. Therefore,
in THR performed with the patient supine and the patient’s coronal
plane parallel to the operating table, we propose that freehand placement
of the acetabular component placement is reliable and reflects standing
(functional) cup position. We examined this hypothesis in 56 hips
in 56 patients (19 men) with a mean age of 61 years (29 to 80) using
three-dimensional CT pelvic reconstructions and standing lateral
pelvic radiographs. We found a low variability of acetabular component
placement, with 46 implants (82%) placed within a combined range
of 30° to 50° inclination and 5° to 25° anteversion. Changing from
the supine to the standing position (analysed in 47 patients) was associated
with an anteversion change <
10° in 45 patients (96%). dPT was
<
10° in 41 patients (87%). In conclusion, supine THR appears
to provide reliable freehand acetabular component placement. In
most patients a small reclination of the pelvis going from supine
to standing causes a small increase in anteversion of the acetabular component Cite this article:
We prospectively assessed the efficacy of a ceramic-on-metal
(CoM) hip bearing with uncemented acetabular and femoral components
in which cobalt–chrome acetabular liners and alumina ceramic heads
were used. The cohort comprised 94 total hip replacements (THRs) in 83 patients
(38 women and 45 men) with a mean age of 58 years (42 to 70). Minimum
follow-up was two years. All patients had pre- and post-operative
assessment using the Western Ontario and McMaster Universities osteoarthritis
index (WOMAC), Oxford hip score and Short-Form 12 scores. All showed
a statistically significant improvement from three months post-operatively
onwards (all p <
0.001). After two years whole blood metal ion levels were measured and
chromosomal analysis was performed. The levels of all metal ions
were elevated except vanadium. Levels of chromium, cobalt, molybdenum
and titanium were significantly higher in patients who underwent
bilateral THR compared with those undergoing unilateral THR (p <
0.001).
Chromosomal analysis demonstrated both structural and aneuploidy
mutations. There were significantly more breaks and losses than
in the normal population (p <
0.001). There was no significant
difference in chromosomal aberration between those undergoing unilateral
and bilateral procedures (all analyses p ≥ 0.62). The use of a CoM THR is effective clinically in the short-term,
with no concerns, but the significance of high metal ion levels
and chromosomal aberrations in the long-term remains unclear. Cite this article:
The purpose of this study was to examine the
complications and outcomes of total hip replacement (THR) in super-obese
patients (body mass index (BMI) >
50 kg/m2) compared
with class I obese (BMI 30 to 34.9 kg/m2) and normal-weight
patients (BMI 18.5 to 24.9 kg/m2), as defined by the
World Health Organization. A total of 39 THRs were performed in 30 super-obese patients
with a mean age of 53 years (31 to 72), who were followed for a
mean of 4.2 years (2.0 to 11.7). This group was matched with two
cohorts of normal-weight and class I obese patients, each comprising
39 THRs in 39 patients. Statistical analysis was performed to determine differences
among these groups with respect to complications and satisfaction
based on the Western Ontario and McMaster Universities (WOMAC) osteoarthritis
index, the Harris hip score (HHS) and the Short-Form (SF)-12 questionnaire. Super-obese patients experienced significantly longer hospital
stays and higher rates of major complications and readmissions than
normal-weight and class I obese patients. Although super-obese patients
demonstrated reduced pre-operative and post-operative satisfaction
scores, there was no significant difference in improvement, or change in
the score, with respect to HHS or the WOMAC osteoarthritis index. Super-obese patients obtain similar satisfaction outcomes as
class I obese and normal-weight patients with respect to improvement
in their scores. However, they experience a significant increase
in length of hospital stay and major complication and readmission
rates. Cite this article:
The practice of removing a well-fixed cementless
femoral component is associated with high morbidity. Ceramic bearing
couples are low wearing and their use minimises the risk of subsequent
further revision due to the production of wear debris. A total of
165 revision hip replacements were performed, in which a polyethylene-lined acetabular
component was revised to a new acetabular component with a ceramic
liner, while retaining the well-fixed femoral component. A titanium
sleeve was placed over the used femoral trunnion, to which a ceramic
head was added. There were 100 alumina and 65 Delta bearing couples
inserted. The mean Harris hip score improved significantly from 71.3 (9.0
to 100.0) pre-operatively to 91.0 (41.0 to 100.0) at a mean follow
up of 4.8 years (2.1 to 12.5) (p <
0.001). No patients reported
squeaking of the hip. There were two fractures of the ceramic head, both in alumina
bearings. No liners were seen to fracture. No fractures were observed
in components made of Delta ceramic. At 8.3 years post-operatively
the survival with any cause of failure as the endpoint was 96.6%
(95% confidence interval (CI) 85.7 to 99.3) for the acetabular component and
94.0% (95% CI 82.1 to 98.4) for the femoral component. The technique of revising the acetabular component in the presence
of a well-fixed femoral component with a ceramic head placed on
a titanium sleeve over the used trunnion is a useful adjunct in
revision hip practice. The use of Delta ceramic is recommended. Cite this article:
Early total hip replacement (THR) for acetabular
fractures offers accelerated rehabilitation, but a high risk of heterotopic
ossification (HO) has been reported. The purpose of this study was
to evaluate the incidence of HO, its associated risk factors and
functional impact. A total of 40 patients with acetabular fractures
treated with a THR weres retrospectively reviewed. The incidence
and severity of HO were evaluated using the modified Brooker classification,
and the functional outcome assessed. The overall incidence of HO
was 38%
(n = 15), with nine severe grade III cases. Patients who underwent
surgery early after injury had a fourfold increased chance of developing
HO. The mean blood loss and operating time were more than twice
that of those whose surgery was delayed (p = 0.002 and p <
0.001,
respectively). In those undergoing early THR, the incidence of grade
III HO was eight times higher than in those in whom THR was delayed
(p = 0.01). Only three of the seven patients with severe HO showed
good or excellent Harris hip scores compared with eight of nine
with class 0, I or II HO (p = 0.049). Associated musculoskeletal
injuries, high-energy trauma and head injuries were associated with
the development of grade III HO. The incidence of HO was significantly higher in patients with
a displaced acetabular fracture undergoing THR early compared with
those undergoing THR later and this had an adverse effect on the
functional outcome. Cite this article:
In a double-blinded randomised controlled trial,
83 patients with primary osteoarthritis of the hip received either
a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement
(THR). The implants differed only in the bearing surfaces used.
The serum levels of cobalt and chromium and functional outcome scores
were compared pre-operatively and at six and 12 months post-operatively. Data were available for 41 CoM and 36 MoM THRs (four patients
were lost to follow-up, two received incorrect implants). The baseline
characteristics of both cohorts were similar. Femoral head size
measured 36 mm in all but two patients who had 28 mm heads. The
mean serum cobalt and chromium levels increased in both groups,
with no difference noted between groups at six months (cobalt p
= 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium
p = 0.76) post-operatively. Similarly, the mean Oxford hip scores,
Western Ontario and McMaster Universities Osteoarthritis index and
University of California, Los Angeles activity scores showed comparable improvement
at 12 months. Our findings indicate that CoM and MoM couplings are associated
with an equivalent increase in serum cobalt and chromium levels,
and comparable functional outcome scores at six and 12-months follow-up.
The inherent challenges of total hip replacement
(THR) in children include the choice of implant for the often atypical
anatomical morphology, its fixation to an immature growing skeleton
and the bearing surface employed to achieve a successful long-term
result. We report the medium-term results of 52 consecutive uncemented
THRs undertaken in
35 paediatric patients with juvenile idiopathic arthritis. The mean
age at the time of surgery was 14.4 years (10 to 16). The median
follow-up was 10.5 years (6 to 15). During the study period 13 THRs
underwent revision surgery. With revision as an endpoint, subgroup
analysis revealed 100% survival of the 23 ceramic-on-ceramic THRs
and 55% (16 of 29) of the metal- or ceramic-on-polyethylene. This
resulted in 94% (95% CI 77.8 to 98.4) survivorship of the femoral
component and 62% (95% CI 41.0 to 78.0) of the acetabular component.
Revision of the acetabular component for wear and osteolysis were
the most common reasons for failure accounting for 11 of the 13
revisions. The success seen in patients with a ceramic-on-ceramic articulation
seems to indicate that this implant strategy has the potential to
make a major difference to the long-term outcome in this difficult
group of patients.
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.
We reviewed the results of 84 total hip replacements performed with a short metaphyseal-fitting anatomical cementless femoral component in 84 unselected consecutive patients with a mean age of 78.9 years (70 to 88). The mean follow-up was 4.6 years (4 to 5). The mean pre-operative Harris hip score was 26 points (0 to 56), which improved to 89 (61 to 100) at the final follow-up. No patient had thigh pain. The mean pre-operative Western Ontario and McMaster Universities osteoarthritis index score was 61 points (48 to 75), which improved to 21 (6 to 46). The mean University of California, Los Angeles activity score was 5.5 points (3 to 7) at the final follow-up. Osseointegration was seen in all femoral and acetabular components. All hips had grade 1 stress shielding of the proximal femur. No acetabular or femoral osteolysis was identified. These results demonstrate that a short metaphyseal-fitting femoral component achieves optimal fixation without diaphyseal anchorage in elderly patients.
There have been comparatively few studies of the incidence of osteolysis and the survival of hybrid and cementless total hip replacements (THRs) in patients younger than 50 years of age. We prospectively reviewed 78 patients (109 hips) with a hybrid THR having a mean age of 43.4 years (21 to 50) and 79 patients (110 hips) with a cementless THR with a mean age of 46.8 years (21 to 49). The patients were evaluated clinically using the Harris hip score, the Western Ontario and McMaster Universities (WOMAC) osteoarthritis score and the University of California, Los Angeles (UCLA) activity score. Radiographs and CT scans were assessed for loosening and osteolysis. The mean follow-up was for 18.4 years (16 to 19) in both groups. The mean post-operative Harris hip scores (91 points Although the long-term fixation of the acetabular metallic shell and the cemented and cementless femoral components was outstanding, wear and peri-acetabular osteolysis constitute the major challenges of THR in young patients.
The angle of inclination of the acetabular component in total hip replacement is a recognised contributing factor in dislocation and early wear. During non-navigated surgery, insertion of the acetabular component has traditionally been performed at an angle of 45° relative to the sagittal plane as judged by the surgeon’s eye, the operative inclination. Typically, the method used to assess inclination is the measurement made on the postoperative anteroposterior radiograph, the radiological inclination. The aim of this study was to measure the intra-operative angle of inclination of the acetabular component on 60 consecutive patients in the lateral decubitus position when using a posterior approach during total hip replacement. This was achieved by taking intra-operative photographs of the acetabular inserter, representing the acetabular axis, and a horizontal reference. The results were compared with the post-operative radiological inclination. The mean post-operative radiological inclination was 13° greater than the photographed operative inclination, which was unexpectedly high. It appears that in the lateral decubitus position with a posterior approach, the uppermost hemipelvis adducts, thus reducing the apparent operative inclination. Surgeons using the posterior approach in lateral decubitus need to aim for a lower operative inclination than when operating with the patient supine in order to achieve an acceptable radiological inclination.
In a prospective observational study we compared the two-year outcome of lumbar fusion by a simple technique using translaminar screws (n = 57) with a more extensive method using transforaminal lumbar interbody fusion and pedicular screw fixation (n = 63) in consecutive patients with degenerative disease of the lumbar spine. Outcome was assessed using the validated multidimensional Core Outcome Measures Index. Blood loss and operating time were significantly lower in the translaminar screw group (p <
0.01). The complication rates were similar in each group (2% to 4%). In all, 91% of the patients returned their questionnaire at two-years. The groups did not differ in Core Outcome Measures Index score reduction, 3.6 ( The two fusion techniques differed markedly in their extent and the cost of the implants, but were associated with almost identical patient-orientated outcomes. Extensive three-point stabilisation is not always required to achieve satisfactory patient-orientated results at two years.
Ensuring the accuracy of the intra-operative orientation of the acetabular component during a total hip replacement can be difficult. In this paper we introduce a reproducible technique using the transverse acetabular ligament to determine the anteversion of the acetabular component. We have found that this ligament can be identified in virtually every hip undergoing primary surgery. We describe an intra-operative grading system for the appearance of the ligament. This technique has been used in 1000 consecutive cases. During a minimum follow-up of eight months the dislocation rate was 0.6%. This confirms our hypothesis that the transverse acetabular ligament can be used to determine the position of the acetabular component. The method has been used in both conventional and minimally-invasive approaches.
This study reports on ceramic-on-metal (CoM) bearings in total hip replacement. Whole blood metal ion levels were measured. The median increase in chromium and cobalt at 12 months was 0.08 μg/1 and 0.22 μg/1, respectively, in CoM bearings. Comparable values for metal-on-metal (MoM) were 0.48 μg/1 and 0.32 μg/1. The chromium levels were significantly lower in CoM than in MoM bearings (p = 0.02). The cobalt levels were lower, but the difference was not significant. Examination of two explanted ceramic heads revealed areas of thin metal transfer. CoM bearings (one explanted head and acetabular component, one explanted head and new acetabular component, and three new heads and acetabular components) were tested in a hip joint simulator. The explanted head and acetabular component had higher bedding-in. However, after one million cycles all the wear rates were the same and an order of magnitude less than that reported for MoM bearings. There were four outliers in each clinical group, primarily related to component malposition.
We reviewed the initial post-operative radiographs of the Trident acetabulum and identified a problem with seating of the metal-backed ceramic liner. We identified 117 hips in 113 patients who had undergone primary total hip replacement using the Trident shell with a metal-backed alumina liner. Of these, 19 (16.4%) were noted to have incomplete seating of the liner, as judged by plain anteroposterior and lateral radiographs. One case of complete liner dissociation necessitating early revision was not included in the prevalence figures. One mis-seated liner was revised in the early post-operative period and two that were initially incompletely seated were found on follow-up radiographs to have become correctly seated. There may be technical issues with regard to the implanting of this prosthesis of which surgeons should be aware. However, there is the distinct possibility that the Trident shell deforms upon implantation, thereby preventing complete seating of the liner.
Abnormal sagittal kinematics after total knee replacement (TKR) can adversely affect functional outcome. Two important determinants of knee kinematics are component geometry and the presence or absence of a posterior-stabilising mechanism (cam-post). We investigated the influence of these variables by comparing the kinematics of a TKR with a polyradial femur with a single radius design, both with and without a cam-post mechanism. We assessed 55 patients, subdivided into four groups, who had undergone a TKR one year earlier by using an established fluoroscopy protocol in order to examine their kinematics
