There remains confusion in the literature with regard to the spinopelvic relationship, and its contribution to ideal acetabular component position. Critical assessment of the literature has been limited by use of conflicting
Aims. The aim of this study was to investigate the differences in 30-day outcomes between patients undergoing revision for an infected total hip arthroplasty (THA) compared with an aseptic revision THA. Patients and Methods. This was a retrospective review of prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database, between 2012 and 2017, using Current Procedural
Aims. Advances in surgical technique and implant design may influence the incidence and mechanism of failure resulting in revision total hip arthroplasty (rTHA). The purpose of the current study was to characterize aetiologies requiring rTHA, and to determine whether temporal changes existed in these aetiologies over a ten-year period. Methods. All rTHAs performed at a single institution from 2009 to 2019 were identified. Demographic information and mode of implant failure was obtained for all patients. Data for rTHA were stratified into two time periods to assess for temporal changes: 2009 to 2013, and 2014 to 2019. Operative reports, radiological imaging, and current procedural
Aims. Total hip arthroplasty (THA) is gaining popularity as a treatment for displaced femoral neck fractures (FNFs), especially in physiologically younger patients. While THA for osteoarthritis (OA) has demonstrated low complication rates and increased quality of life, results of THA for acute FNF are not as clear. Currently, a THA performed for FNF is included in an institutional arthroplasty bundle without adequate risk adjustment, potentially placing centres participating in fracture care at financial disadvantage. The purpose of this study is to report on perioperative complication rates after THA for FNF compared with elective THA performed for OA of the hip. Patients and Methods. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database between 2008 and 2016 was queried. Patients were identified using the THA Current Procedural
The Unified Classification System (UCS) emphasises
the key principles in the assessment and management of peri-prosthetic
fractures complicating partial or total joint replacement. We tested the inter- and intra-observer agreement for the UCS
as applied to the pelvis and femur using 20 examples of peri-prosthetic
fracture in 17 patients. Each subtype of the UCS was represented
by at least one case. Specialist orthopaedic surgeons (experts)
and orthopaedic residents (pre-experts) assessed reliability on
two separate occasions. For the pelvis, the UCS showed inter-observer agreement of 0.837
(95% confidence intervals (CI) 0.798 to 0.876) for the experts and
0.728 (95% CI 0.689 to 0.767) for the pre-experts. The intra-observer
agreement for the experts was 0.861 (95% CI 0.760 to 0.963) and
0.803 (95% 0.688 to 0.918) for the pre-experts. For the femur, the
UCS showed an inter-observer kappa value of 0.805 (95% CI 0.765
to 0.845) for the experts and a value of 0.732 (95% CI 0.690 to 0.773)
for the pre-experts. The intra-observer agreement was 0.920 (95%
CI 0.867 to 0.973) for the experts, and 0.772 (95% CI 0.652 to 0.892)
for the pre-experts. This corresponds to a substantial and ‘almost
perfect’ inter- and intra-observer agreement for the UCS for peri-prosthetic
fractures of the pelvis and femur. We hope that unifying the
Adverse spinal motion or balance (spine mobility) and adverse pelvic mobility, in combination, are often referred to as adverse spinopelvic mobility (SPM). A stiff lumbar spine, large posterior standing pelvic tilt, and severe sagittal spinal deformity have been identified as risk factors for increased hip instability. Adverse SPM can create functional malposition of the acetabular components and hence is an instability risk. Adverse pelvic mobility is often, but not always, associated with abnormal spinal motion parameters. Dislocation rates for dual-mobility articulations (DMAs) have been reported to be between 0% and 1.1%. The aim of this study was to determine the early survivorship from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) of patients with adverse SPM who received a DMA. A multicentre study was performed using data from 227 patients undergoing primary total hip arthroplasty (THA), enrolled consecutively. All the patients who had one or more adverse spine or pelvic mobility parameter had a DMA inserted at the time of their surgery. The mean age was 76 years (22 to 93) and 63% were female (n = 145). At a mean of 14 months (5 to 31) postoperatively, the AOANJRR was analyzed for follow-up information. Reasons for revision and types of revision were identified.Aims
Methods
The aim of this study was to estimate time to arthroplasty among patients with hip and knee osteoarthritis (OA), and to identify factors at enrolment to first-line intervention that are prognostic for progression to surgery. In this longitudinal register-based observational study, we identified 72,069 patients with hip and knee OA in the Better Management of Patients with Osteoarthritis Register (BOA), who were referred for first-line OA intervention, between May 2008 and December 2016. Patients were followed until the first primary arthroplasty surgery before 31 December 2016, stratified into a hip and a knee OA cohort. Data were analyzed with Kaplan-Meier and multivariable-adjusted Cox regression.Aims
Methods
Total hip arthroplasties (THAs) are performed by surgeons at various stages in training with varying levels of supervision, but we do not know if this is safe practice with comparable outcomes to consultant-performed THA. Our aim was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THA. We performed an observational study using National Joint Registry (NJR) data. We included adult patients who underwent primary THA for osteoarthritis, recorded in the NJR between 2003 and 2016. Exposures were operating surgeon grade (consultant or trainee) and whether or not trainees were directly supervised by a scrubbed consultant. Outcomes were all-cause revision and the indication for revision up to ten years. We used methods of survival analysis, adjusted for patient, operation, and healthcare setting factors.Aims
Methods
The aim of this study was to perform a cross-cultural adaptation of Oxford Hip Score (OHS) to Indonesian, and to evaluate its psychometric properties. We performed a cross-cultural adaptation of Oxford Hip Score into Indonesian language (OHS-ID) and determined its internal consistency, test-retest reliability, measurement error, floor-ceiling effect, responsiveness, and construct validity by hypotheses testing of its correlation with Harris Hip Score (HHS), vsual analogue scale (VAS), and Short Form-36 (SF-36). Adults (> 17 years old) with chronic hip pain (osteoarthritis or osteonecrosis) were included.Aims
Methods
As our population ages, the number of octogenarians who will require a total hip arthroplasty (THA) rises. In a value-based system where operative outcomes are linked to hospital payments, it is necessary to assess the outcomes in this population. The purpose of this study was to compare outcomes of elective, primary THA in patients ≥ 80 years old to those aged < 80. A retrospective review of 10,251 consecutive THA cases from 2011 to 2019 was conducted. Patient-reported outcome (PRO) scores (Hip disability and Osteoarthritis Outcome Score (HOOS)), as well as demographic, readmission, and complication data, were collected.Aims
Methods
Outcomes following different types of surgical intervention for femoroacetabular impingement (FAI) are well reported individually but comparative data are deficient. The purpose of this study was to conduct a systematic review (SR) and meta-analysis to analyze the outcomes following surgical management of FAI by hip arthroscopy (HA), anterior mini open approach (AMO), and surgical hip dislocation (SHD). This SR was registered with PROSPERO. An electronic database search of PubMed, Medline, and EMBASE for English and German language articles over the last 20 years was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We specifically analyzed and compared changes in patient-reported outcome measures (PROMs), α-angle, rate of complications, rate of revision, and conversion to total hip arthroplasty (THA). A total of 48 articles were included for final analysis with a total of 4,384 hips in 4,094 patients. All subgroups showed a significant correction in mean α angle postoperatively with a mean change of 28.8° (95% confidence interval (CI) 21 to 36.5; p < 0.01) after AMO, 21.1° (95% CI 15.1 to 27; p < 0.01) after SHD, and 20.5° (95% CI 16.1 to 24.8; p < 0.01) after HA. The AMO group showed a significantly higher increase in PROMs (3.7; 95% CI 3.2 to 4.2; p < 0.01) versus arthroscopy (2.5; 95% CI 2.3 to 2.8; p < 0.01) and SHD (2.4; 95% CI 1.5 to 3.3; p < 0.01). However, the rate of complications following AMO was significantly higher than HA and SHD. All three surgical approaches offered significant improvements in PROMs and radiological correction of cam deformities. All three groups showed similar rates of revision procedures but SHD had the highest rate of conversion to a THA. Revision rates were similar for all three revision procedures.
Although there is increasing legalization of the use of cannabis in the USA, few well-powered studies have evaluated the association between cannabis use disorder and outcomes following primary total hip arthroplasty (THA). Thus, the aim of this study was to determine whether patients who use cannabis and undergo primary THA have higher rates of in-hospital length of stay (LOS), medical complications, implant-related complications, and costs. Using an administrative database, patients with cannabis use disorder undergoing primary THA were matched to a control group in a 1:5 ratio by age, sex, and various medical comorbidities. This yielded 23,030 patients (3,842 in the study group matched with 19,188 in the control group). The variables which were studied included LOS, 90-day medical complications, two-year implant-related complications, and 90-day costs of care. Mann-Whitney U tests were used to compare LOS and costs. Multivariate logistic regression analyses were used to calculate the odds ratios (ORs) of developing complications.Aims
Methods
Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method. We retrospectively reviewed all patients undergoing THA via the DAA between 2011 and 2017 at our institution. Primary outcome was dislocation at minimum two-year follow-up. Patients were stratified by demographic details and risk factors for dislocation, and an in-depth analysis of dislocations was performed.Aims
Methods
It has been suggested that the direct anterior approach (DAA) should be used for total hip arthroplasty (THA) instead of the posterior approach (PA) for better early functional outcomes. We conducted a value-based analysis of the functional outcome and associated perioperative costs, to determine which surgical approach gives the better short-term outcomes and lower costs. This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and the Cochrane Handbook. Several online databases were searched. Non-stratified and stratified meta-analyses were conducted to test the confounding biases in the studies which were included. The mean cost and probability were used to determine the added costs of perioperative services.Aims
Methods
Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction. A group of 1,000 randomly selected clinical and hospital notes from eight different surgeons were collected for patients undergoing primary arthroplasty between 2012 and 2018. In all, 19 preoperative, 17 operative, and two postoperative variables of interest were manually extracted from these notes. A NLP algorithm was created to automatically extract these variables from a training sample of these notes, and the algorithm was tested on a random test sample of notes. Performance of the NLP algorithm was measured in Statistical Analysis System (SAS) by calculating the accuracy of the variables collected, the ability of the algorithm to collect the correct information when it was indeed in the note (sensitivity), and the ability of the algorithm to not collect a certain data element when it was not in the note (specificity).Aims
Methods
Earlier studies dealing with trends in the management of osteonecrosis of the femoral head (ONFH) identified an increasing rate of total hip arthroplasties (THAs) and a decreasing rate of joint-preserving procedures between 1992 and 2008. In an effort to assess new trends in the management of this condition, this study evaluated the annual trends of joint-preserving versus arthroplasties for patients aged < or > 50 years old, and the incidence of specific operative management techniques. A total of 219,371 patients with ONFH were identified from a nationwide database between 1 January 2009 and 31 December 2015. The mean age was 54 years (18 to 90) and 105,298 (48%) were female. The diagnosis was made using International Classification of Disease, Ninth revision, Clinical Modification (ICD-9-CM) and Tenth Revision, Clinical Modification (ICD-10-CM) procedure codes. The percentage of patients managed using each procedure during each year was calculated and compared between years. The trends in the use of the types of procedure were also evaluated.Aims
Methods
The primary aim of this paper was to outline the processes involved in building the Partners Arthroplasty Registry (PAR), established in April 2016 to capture baseline and outcome data for patients undergoing arthroplasty in a regional healthcare system. A secondary aim was to determine the quality of PAR’s data. A tertiary aim was to report preliminary findings from the registry and contributions to quality improvement initiatives and research up to March 2019. Structured Query Language was used to obtain data relating to patients who underwent total hip or knee arthroplasty (THA and TKA) from the hospital network’s electronic medical record (EMR) system to be included in the PAR. Data were stored in a secure database and visualized in dashboards. Quality assurance of PAR data was performed by review of the medical records. Capture rate was determined by comparing two months of PAR data with operating room schedules. Linear and binary logistic regression models were constructed to determine if length of stay (LOS), discharge to a care home, and readmission rates improved between 2016 and 2019.Aims
Methods
Cephalomedullary nails (CMNs) are commonly used for the treatment of intertrochanteric hip fractures. Total hip arthroplasty (THA) may be used as a salvage procedure when fixation fails in these patients. The aim of this study was to analyze the complications of THA following failed intertrochanteric hip fracture fixation using a CMN. Patients who underwent THA were identified from the 5% subset of Medicare Parts A/B between 2002 and 2015. A subgroup involving those with an intertrochanteric fracture that was treated using a CMN during the previous five years was identified and compared with the remaining patients who underwent THA. The length of stay (LOS) was compared using both univariate and multivariate analysis. The incidence of infection, dislocation, revision, and re-admission was compared between the two groups, using multivariate analysis adjusted for demographic, hospital, and clinical factors.Aims
Patients and Methods
The aim of this study was to assess the influence of operating time on 30-day complications following total hip arthroplasty (THA). We identified patients aged 18 years and older who underwent THA between 2006 and 2016 from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We identified 131 361 patients, with a mean age of 65 years (Aims
Patients and Methods
We investigated the reliability of the cobalt-chromium (CoCr) synovial joint fluid ratio (JFR) in identifying the presence of a severe aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) response and/or suboptimal taper performance (SOTP) following metal-on-metal (MoM) hip arthroplasty. We then examined the possibility that the CoCr JFR may influence the serum partitioning of Co and Cr. For part A, we included all revision surgeries carried out at our unit with the relevant data, including volumetric wear analysis, joint fluid (JF) Co and Cr concentrations, and ALVAL grade (n = 315). Receiver operating characteristic curves were constructed to assess the reliability of the CoCr JFR in identifying severe ALVAL and/or SOTP. For part B, we included only patients with unilateral prostheses who had given matched serum and whole blood samples for Co and Cr analysis (n = 155). Multiple regression was used to examine the influence of JF concentrations on the serum partitioning of Co and Cr in the blood.Objectives
Methods
There are limited published data detailing the volumetric material loss from tapers of conventional metal-on-polyethylene (MoP) total hip arthroplasties (THAs). Our aim was to address this by comparing the taper wear rates measured in an explanted cohort of the widely used Exeter THA with those measured in a group of metal-on-metal (MoM) THAs. We examined an existing retrieval database to identify all Exeter V40 and Universal MoP THAs. Volumetric wear analysis of the taper surfaces was conducted using previously validated methodology. These values were compared with those obtained from a series of MoM THAs using non-parametric statistical methodology. A number of patient and device variables were accounted for using multiple regression modelling.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 aim of this study was to compare the rate of perioperative
complications following aseptic revision total hip arthroplasty
(THA) in patients aged ≥ 80 years with that in those aged <
80
years, and to identify risk factors for the incidence of serious
adverse events in those aged ≥ 80 years using a large validated
national database. Patients who underwent aseptic revision THA were identified in
the 2005 to 2015 National Surgical Quality Improvement Program (NSQIP)
database and stratified into two age groups: those aged <
80
years and those aged ≥ 80 years. Preoperative and procedural characteristics
were compared. Multivariate regression analysis was used to compare
the risk of postoperative complications and readmission. Risk factors
for the development of a serious adverse event in those aged ≥ 80
years were characterized.Aims
Patients and Methods
This paper describes the methodology, validation and reliability
of a new computer-assisted method which uses models of the patient’s
bones and the components to measure their migration and polyethylene
wear from radiographs after total hip arthroplasty (THA). Models of the patient’s acetabular and femoral component obtained
from the manufacturer and models of the patient’s pelvis and femur
built from a single computed tomography (CT) scan, are used by a
computer program to measure the migration of the components and
the penetration of the femoral head from anteroposterior and lateral radiographs
taken at follow-up visits. The program simulates the radiographic
setup and matches the position and orientation of the models to
outlines of the pelvis, the acetabular and femoral component, and
femur on radiographs. Changes in position and orientation reflect
the migration of the components and the penetration of the femoral
head. Validation was performed using radiographs of phantoms simulating
known migration and penetration, and the clinical feasibility of
measuring migration was assessed in two patients.Aims
Materials 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
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
Femoral stems with exchangeable (modular) necks were introduced
to offer surgeons an increased choice when determining the version,
offset and length of the femoral neck during total hip arthroplasty
(THA). It was hoped that this would improve outcomes and reduce
complications, particularly dislocation. In 2010, the Australian Orthopaedic
Association National Joint Replacement Registry (AOANJRR) first
reported an increased rate of revision after primary THA using femoral
stems with an exchangeable neck. The aim of this study was to provide
a more comprehensive up-to-date analysis of primary THA using femoral
stems with exchangeable and fixed necks. The data included all primary THA procedures performed for osteoarthritis
(OA), reported to the AOANJRR between 01 September 1999 and 31 December
2014. There were 9289 femoral stems with an exchangeable neck and
253 165 femoral stems with a fixed neck. The characteristics of
the patients and prostheses including the bearing surface and stem/neck
metal combinations were examined using Cox proportional hazard ratios
(HRs) and Kaplan-Meier estimates of survivorship. Aims
Materials and Methods
Using a systematic review, we investigated whether there is an
increased risk of post-operative infection in patients who have
received an intra-articular corticosteroid injection to the hip
for osteoarthritis prior to total hip arthroplasty (THA). Studies dealing with an intra-articular corticosteroid injection
to the hip and infection following subsequent THA were identified
from databases for the period between 1990 to 2013. Retrieved articles
were independently assessed for their methodological quality.Aims
Methods
This study investigates and defines the topographic
anatomy of the medial femoral circumflex artery (MFCA) terminal
branches supplying the femoral head (FH). Gross dissection of 14
fresh–frozen cadaveric hips was undertaken to determine the extra
and intracapsular course of the MFCA’s terminal branches. A constant
branch arising from the transverse MFCA (inferior retinacular artery;
IRA) penetrates the capsule at the level of the anteroinferior neck,
then courses obliquely within the fibrous prolongation of the capsule
wall (inferior retinacula of Weitbrecht), elevated from the neck,
to the posteroinferior femoral head–neck junction. This vessel has
a mean of five (three to nine) terminal branches, of which the majority
penetrate posteriorly. Branches from the ascending MFCA entered
the femoral capsular attachment posteriorly, running deep to the
synovium, through the neck, and terminating in two branches. The
deep MFCA penetrates the posterosuperior femoral capsular. Once
intracapsular, it divides into a mean of six (four to nine) terminal
branches running deep to the synovium, within the superior retinacula
of Weitbrecht of which 80% are posterior. Our study defines the
exact anatomical location of the vessels, arising from the MFCA
and supplying the FH. The IRA is in an elevated position from the
femoral neck and may be protected from injury during fracture of
the femoral neck. We present vascular ‘danger zones’ that may help
avoid iatrogenic vascular injury during surgical interventions about
the hip. 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 piriformis muscle is an important landmark
in the surgical anatomy of the hip, particularly the posterior approach
for total hip replacement (THR). Standard orthopaedic teaching dictates
that the tendon must be cut in to allow adequate access to the superior
part of the acetabulum and the femoral medullary canal. However,
in our experience a routine THR can be performed through a posterior
approach without sacrificing this tendon. We dissected the proximal femora of 15 cadavers in order to clarify
the morphological anatomy of the piriformis tendon. We confirmed
that the tendon attaches on the crest of the greater trochanter,
in a position superior to the trochanteric fossa, away from the
entry point for broaching the intramedullary canal during THR. The
tendon attachment site encompassed the summit and medial aspect
of the greater trochanter as well as a variable attachment to the
fibrous capsule of the hip joint. In addition we dissected seven
cadavers resecting all posterior attachments except the piriformis
muscle and tendon in order to study their relations to the hip joint,
as the joint was flexed. At flexion of 90° the piriformis muscle
lay directly posterior to the hip joint. The piriform fossa is a term used by orthopaedic surgeons to
refer the trochanteric fossa and normally has no relation to the
attachment site of the piriformis tendon. In hip flexion the piriformis
lies directly behind the hip joint and might reasonably be considered
to contribute to the stability of the joint. We conclude that the anatomy of the piriformis muscle is often
inaccurately described in the current surgical literature and terms
are used and interchanged inappropriately. 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:
Juvenile idiopathic arthritis (JIA) is a chronic disease of childhood; it causes joint damage which may require surgical intervention, often in the young adult. The aim of this study was to describe the long-term outcome and survival of hip replacement in a group of adult patients with JIA and to determine predictors of survival for the prosthesis. In this retrospective comparative study patients were identified from the database of a regional specialist adult JIA clinic. This documented a series of 47 hip replacements performed in 25 adult patients with JIA. Surgery was performed at a mean age of 27 years (11 to 47), with a mean follow-up of 19 years (2 to 36). The mean Western Ontario and McMaster Universities osteoarthritis index questionnaire (WOMAC) score at the last follow-up was 53 (19 to 96) and the mean Health Assessment Questionnaire score was 2.25 (0 to 3). The mean pain component of the WOMAC score (60 (20 to 100)) was significantly higher than the mean functional component score (46 (0 to 97)) (p = 0.02). Kaplan-Meier survival analysis revealed a survival probability of 46.6% (95% confidence interval 37.5 to 55.7) at 19 years, with a trend towards enhanced survival with the use of a cemented acetabular component and a cementless femoral component. This was not, however, statistically significant (acetabular component, p = 0.76, femoral component, p = 0.45). Cox’s proportional hazards regression analysis showed an implant survival rate of 54.9% at 19 years at the mean of covariates. Survival of the prosthesis was significantly poorer (p = 0.001) in patients who had been taking long-term corticosteroids and significantly better (p = 0.02) in patients on methotrexate.
We studied survival to 38 years after Charnley low-friction arthroplasty of the hip. We used revision as an end-point, while adopting a policy of regular follow-up and early revision for radiological changes alone if indicated. Between November 1962 and June 2005, 22 066 primary low-friction arthroplasties (17 409 patients) had been performed at Wrightington Hospital by more than 330 surgeons. By June 2006, 1001 (4.5%) hips had been revised and 1490 patients (2662 hips, 12%) had died. At 31 years, where a minimum of 40 hips were still attending follow-up, survival with revision for infection as an endpoint was 95%, for dislocation 98%, for a fractured stem 88.6%, for a loose stem 72.5% and for a loose acetabular component 53.7%. Wear and loosening of the ultra-high-molecular-weight polyethylene acetabular component were the main long-term problems. We conclude that regular follow-up after hip replacement is essential and that all operative findings should be recorded at revision.
The inferior gluteal artery is described in standard anatomy textbooks as contributing to the blood supply of the hip through an anastomosis with the medial femoral circumflex artery. The site(s) of the anastomosis has not been described previously. We undertook an injection study to define the anastomotic connections between these two arteries and to determine whether the inferior gluteal artery could supply the lateral epiphyseal arteries alone. From eight fresh-frozen cadaver pelvic specimens we were able to inject the vessels in 14 hips with latex moulding compound through either the medial femoral circumflex artery or the inferior gluteal artery. Injected vessels around the hip were then carefully exposed and documented photographically. In seven of the eight specimens a clear anastomosis was shown between the two arteries adjacent to the tendon of obturator externus. The terminal vessel arising from this anastomosis was noted to pass directly beneath the posterior capsule of the hip before ascending the superior aspect of the femoral neck and terminating in the lateral epiphyseal vessels. At no point was the terminal vessel found between the capsule and the conjoined tendon. The medial femoral circumflex artery receives a direct supply from the inferior gluteal artery immediately before passing beneath the capsule of the hip. Detailed knowledge of this anatomy may help to explain the development of avascular necrosis after hip trauma, as well as to allow additional safe surgical exposure of the femoral neck and head.
We report the clinical and radiological outcome at ten years of 104 primary total hip replacements (100 patients) using the Metasul metal-on-metal bearing. Of these, 52 had a cemented Stuehmer-Weber polyethylene acetabular component with a Metasul bearing and 52 had an uncemented Allofit acetabular component with a Metasul liner. A total of 15 patients (16 hips) died before their follow-up at ten years and three were lost to follow-up. The study group therefore comprised 82 patients (85 hips). The mean Oxford score at ten years was 20.7 (12 to 42). Six of 85 hips required revision surgery. One was performed because of infection, one for aseptic loosening of the acetabular component and four because of unexplained pain. Histological examination showed an aseptic lymphocytic vasculitis associated lesion-type tissue response in two of these. Continued follow-up is advocated in order to monitor the long-term performance of the Metasul bearing and tissue responses to metal debris.
New brands of joint prosthesis are released for general implantation with limited evidence of their long-term performance in patients. The CUSUM continuous monitoring method is a statistical testing procedure which could be used to provide prospective evaluation of brands as soon as implantation in patients begins and give early warning of poor performance. We describe the CUSUM and illustrate the potential value of this monitoring tool by applying it retrospectively to the 3M Capital Hip experience. The results show that if the clinical data and methodology had been available, the CUSUM would have given an alert to the underperformance of this prosthesis almost four years before the issue of a Hazard Notice by the Medical Devices Agency. This indicates that the CUSUM can be a valuable tool in monitoring joint prostheses, subject to timely and complete collection of data. Regional or national joint registries provide an opportunity for future centralised, continuous monitoring of all hip and knee prostheses using these techniques.
Neurogenic myositis ossificans is a disabling condition affecting the large joints of patients with severe post-traumatic impairment of the central nervous system. It can result in ankylosis of the joint and vascular or neural compression. Surgery may be hazardous with potential haemorrhage, neurovascular injury, iatrogenic fracture and osteochondral injury. We undertook pre-operative volumetric CT assessment of 45 ankylosed hips with neurogenic myositis ossificans which required surgery. Helical CT with intravenous contrast, combined with two- and three-dimensional surface reconstructions, was the only pre-operative imaging procedure. This gave good differentiation of the heterotopic bone from the adjacent vessels. We established that early surgery, within 24 months of injury, was neither complicated by peri-operative fracture nor by the early recurrence of neurogenic myositis ossificans. Surgical delay was associated with a loss of joint space and a greater degree of bone demineralisation. Enhanced volumetric CT is an excellent method for the pre-operative assessment of neurogenic myositis ossificans and correlates well with the operative findings.
We describe the results at five years of a prospective study of a new tri-tapered polished, cannulated, cemented femoral stem implanted in 51 patients (54 hips) with osteoarthritis. The mean age and body mass index of the patients was 74 years and 27.9, respectively. Using the anterolateral approach, half of the stems were implanted by a consultant orthopaedic surgeon and half by six different registrars. There were three withdrawals from the study because of psychiatric illness, a deep infection and a recurrent dislocation. Five deaths occurred prior to five-year follow-up and one patient withdrew from clinical review. In the remaining 51 hips the mean pre-operative Oxford hip score was 47 points which decreased to 19 points at five years (45 hips). Of the stems 49 (98%) were implanted within 1° of neutral in the femoral canal. The mean migration of the stem at five years was 1.9 mm and the survivorship for aseptic loosening was 100%. There was no significant difference in outcome between the consultant and registrar groups. At five years, the results were comparable with those of other polished, tapered, cemented stems. Long-term surveillance continues.
We evaluated the long-term results of 116 total hip replacements with a superolateral shelfplasty in 102 patients with osteoarthritis secondary to developmental dysplasia of the hip. After a mean follow-up of 19.5 years (11.5 to 26.0), 14 acetabular components (12%) had been revised. The cumulative survival at 20 years was 78%, with revision for loosening of the acetabular component as the end-point. All grafts were well integrated and showed remodelling. In six grafts some resorption had occurred under the heads of the screws where the graft was not supporting the socket. Apart from these 14 revisions, seven acetabular components had possible radiological signs of loosening at a mean follow-up of 14.5 years, one had signs of probable loosening, and five had signs of definite loosening. These results indicate that this technique of bone grafting for acetabular reconstruction in hip dysplasia is a durable solution for cemented acetabular components.
In a longitudinal case-control study, we followed 81 subjects with dysplasia of the hip and 136 control subjects without dysplasia for ten years assessing radiological evidence of degeneration of the hip at admission and follow-up. There were no cases of subluxation in the group with dysplasia. Neither subjects with dysplasia nor controls had radiological signs of ongoing degenerative disease at admission. The primary radiological discriminator of degeneration of the hip was a change in the minimum joint space width over time. There were no significant differences between these with dysplasia and controls in regard to age, body mass index or occupational exposure to daily repeated lifting at admission. We found no significant differences in the reduction of the joint space width at follow-up between subjects with dysplasia and the control subjects nor in self-reported pain in the hip. The association of subluxation and/or associated acetabular labral tears with dysplasia of the hip may be a conditional factor for the development of premature osteoarthritis in mildly to moderately dysplastic hips.
