Aims. Some patients presenting with hip pain and instability and underlying acetabular dysplasia (AD) do not experience resolution of symptoms after surgical management. Hip-spine syndrome is a possible underlying cause. We hypothesized that there is a higher frequency of radiological spine anomalies in patients with AD. We also assessed the relationship between radiological severity of AD and frequency of spine anomalies. Methods. In a retrospective analysis of registry data, 122 hips in 122 patients who presented with hip pain and and a final diagnosis of AD were studied. Two observers analyzed hip and spine variables using standard radiographs to assess AD. The frequency of lumbosacral
Aims. Dual mobility implants in total hip arthroplasty are designed to increase the functional head size, thus decreasing the potential for dislocation. Modular dual mobility (MDM) implants incorporate a metal liner (e.g. cobalt-chromium alloy) in a metal shell (e.g. titanium alloy), raising concern for mechanically assisted crevice corrosion at the modular liner-shell connection. We sought to examine fretting and corrosion on MDM liners, to analyze the corrosion products, and to examine histologically the periprosthetic tissues. Methods. A total of 60 retrieved liners were subjectively scored for fretting and corrosion. The corrosion products from the three most severely corroded implants were removed from the implant surface, imaged using scanning electron microscopy, and analyzed using Fourier-transform infrared spectroscopy. Results. Fretting was present on 88% (53/60) of the retrieved liners, and corrosion was present on 97% (58/60). Fretting was most often found on the lip of the taper at the
Aims. The rate of dislocation when traditional single bearing implants are used in revision total hip arthroplasty (THA) has been reported to be between 8% and 10%. The use of dual mobility bearings can reduce this risk to between 0.5% and 2%. Dual mobility bearings are more expensive, and it is not clear if the additional clinical benefits constitute value for money for the payers. We aimed to estimate the cost-effectiveness of dual mobility compared with single bearings for patients undergoing revision THA. Methods. We developed a Markov model to estimate the expected cost and benefits of dual mobility compared with single bearing implants in patients undergoing revision THA. The rates of revision and further revision were calculated from the National Joint Registry of England and Wales, while rates of
Our objective was describing an algorithm to identify and prevent vascular injury in patients with intrapelvic components. Patients were defined as at risk to vascular injuries when components or cement migrated 5 mm or more beyond the ilioischial line in any of the pelvic incidences (anteroposterior and Judet view). In those patients, a serial investigation was initiated by a CT angiography, followed by a vascular surgeon evaluation. The investigation proceeded if necessary. The main goal was to assure a safe tissue plane between the hardware and the vessels.Aims
Methods
Eccentric reductions may become concentric through femoral head ‘docking’ (FHD) following closed reduction (CR) for developmental dysplasia of the hip (DDH). However, changes regarding position and morphology through FHD are not well understood. We aimed to assess these changes using serial MRI. We reviewed 103 patients with DDH successfully treated by CR and spica casting in a single institution between January 2016 and December 2020. MRI was routinely performed immediately after CR and at the end of each cast. Using MRI, we described the labrum-acetabular cartilage complex (LACC) morphology, and measured the femoral head to triradiate cartilage distance (FTD) on the midcoronal section. A total of 13 hips with initial complete reduction (i.e. FTD < 1 mm) and ten hips with incomplete MRI follow-up were excluded. A total of 86 patients (92 hips) with a FTD > 1 mm were included in the analysis.Aims
Methods
We have investigated the effectiveness of the transplantation of bone-marrow-derived mononuclear cells (BMMNCs) with interconnected porous calcium hydroxyapatite (IP-CHA) on early bone repair for osteonecrosis of the femoral head. We studied 22 patients (30 hips) who had osteonecrosis with a minimum follow-up of one year after implantation of BMMNCs. The mean age at surgery was 41 years (18 to 64) and the mean period of follow-up was 29 months (19 to 48). In a control group, cell-free IP-CHA was implanted into a further eight patients (9 hips) with osteonecrosis of the femoral head and the outcomes were compared. A reduction in the size of the osteonecrotic lesion was observed subsequent to hypertrophy of the bone in the
The primary aim of this study was to determine the ten-year outcome following surgical treatment for femoroacetabular impingement (FAI). We assessed whether the evolution of practice from open to arthroscopic techniques influenced outcomes and tested whether any patient, radiological, or surgical factors were associated with outcome. Prospectively collected data of a consecutive single-surgeon cohort, operated for FAI between January 2005 and January 2015, were retrospectively studied. The cohort comprised 393 hips (365 patients; 71% male (n = 278)), with a mean age of 34.5 years (SD 10.0). Over the study period, techniques evolved from open surgical dislocation (n = 94) to a combined arthroscopy-Hueter technique (HA + Hueter; n = 61) to a pure arthroscopic technique (HA; n = 238). Outcome measures of interest included modes of failures, complications, reoperation, and patient-reported outcome measures (PROMs). Demographic, radiological, and surgical factors were tested for possible association with outcome.Aims
Methods
Damage to and repair of the acetabular labral-chondral complex are areas of clinical interest in the treatment of young adults with pain in the hip and in the prevention of degenerative arthritis of the hip. There are varying theories as to why most acetabular tears are located anterosuperiorly. We have studied the prenatal development of the human acetabular labral-chondral complex in 11 fetal hips, aged from eight weeks of gestation to term. There were consistent differences between the anterior and posterior acetabular labral-chondral complex throughout all ages of gestation. The anterior labrum had a somewhat marginal attachment to the acetabular cartilage with an intra-articular projection. The posterior labrum was attached and continuous with the acetabular cartilage. Anteriorly, the labral-chondral
The volume of ambulatory total hip arthroplasty (THA) procedures is increasing due to the emphasis on value-based care. The purpose of the study is to identify the causes for failed same-day discharge (SDD) and perioperative factors leading to failed SDD. This retrospective cohort study followed pre-selected patients for SDD THA from 1 August 2018 to 31 December 2020. Inclusion criteria were patients undergoing unilateral THA with appropriate social support, age 18 to 75 years, and BMI < 37 kg/m2. Patients with opioid dependence, coronary artery disease, and valvular heart disease were excluded. Demographics, comorbidities, and perioperative data were collected from the electronic medical records. Possible risk factors for failed SDD were identified using multivariate logistic regression.Aims
Methods
The risk factors for abnormal spinopelvic mobility (SPM), defined as an anterior rotation of the spinopelvic tilt (∆SPT) ≥ 20° in a flexed-seated position, have been described. The implication of pelvic incidence (PI) is unclear, and the concept of lumbar lordosis (LL) based on anatomical limits may be erroneous. The distribution of LL, including a unusual shape in patients with a high lordosis, a low pelvic incidence, and an anteverted pelvis seems more relevant. The clinical data of 311 consecutive patients who underwent total hip arthroplasty was retrospectively analyzed. We analyzed the different types of lumbar shapes that can present in patients to identify their potential associations with abnormal pelvic mobility, and we analyzed the potential risk factors associated with a ∆SPT ≥ 20° in the overall population.Aims
Methods
Perthes’ disease is an uncommon hip disorder with limited data on the long-term outcomes in adulthood. We partnered with community-based foundations and utilized web-based survey methodology to develop the Adult Perthes Survey, which includes demographics, childhood and adult Perthes’ disease history, the University of California Los Angeles (UCLA) Activity Scale item, Short Form-36, the Hip disability and Osteoarthritis Outcome Score, and a body pain diagram. Here we investigate the following questions: 1) what is the feasibility of obtaining > 1,000 survey responses from adults who had Perthes’ disease using a web-based platform?; and 2) what are the baseline characteristics and demographic composition of our sample? The survey link was available publicly for 15 months and advertised among support groups. Of 1,505 participants who attempted the Adult Perthes survey, 1,182 completed it with a median timeframe of 11 minutes (IQR 8.633 to 14.72). Participants who dropped out were similar to those who completed the survey on several fixed variables. Participants represented 45 countries including the USA (n = 570; 48%), UK (n = 295; 25%), Australia (n = 133; 11%), and Canada (n = 46; 4%). Of the 1,182 respondents, 58% were female and the mean age was 39 years (SD 12.6).Aims
Methods
The aim of this study was to identify the optimal lip position for total hip arthroplasties (THAs) using a lipped liner. There is a lack of consensus on the optimal position, with substantial variability in surgeon practice. A model of a THA was developed using a 20° lipped liner. Kinematic analyses included a physiological range of motion (ROM) analysis and a provocative dislocation manoeuvre analysis. ROM prior to impingement was calculated and, in impingement scenarios, the travel distance prior to dislocation was assessed. The combinations analyzed included nine cup positions (inclination 30-40-50°, anteversion 5-15-25°), three stem positions (anteversion 0-15-30°), and five lip orientations (right hip 7 to 11 o’clock).Aims
Methods
Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSSstand-sit) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at
six weeks and a minimum of
one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria.Aims
Methods
Total hip arthroplasty (THA) with dual-mobility components (DM-THA) has been shown to decrease the risk of dislocation in the setting of a displaced neck of femur fracture compared to conventional single-bearing THA (SB-THA). This study assesses if the clinical benefit of a reduced dislocation rate can justify the incremental cost increase of DM-THA compared to SB-THA. Costs and benefits were established for patients aged 75 to 79 years over a five-year time period in the base case from the Canadian Health Payer’s perspective. One-way and probabilistic sensitivity analysis assessed the robustness of the base case model conclusions.Aims
Methods
This study aims to assess the feasibility of conducting a pragmatic, multicentre randomized controlled trial (RCT) to test the clinical and cost-effectiveness of an informal caregiver training programme to support the recovery of people following hip fracture surgery. This will be a mixed-methods feasibility RCT, recruiting 60 patients following hip fracture surgery and their informal caregivers. Patients will be randomized to usual NHS care, versus usual NHS care plus a caregiver-patient dyad training programme (HIP HELPER). This programme will comprise of three, one-hour, one-to-one training sessions for the patient and caregiver, delivered by a nurse, physiotherapist, or occupational therapist. Training will be delivered in the hospital setting pre-patient discharge. It will include practical skills for rehabilitation such as: transfers and walking; recovery goal setting and expectations; pacing and stress management techniques; and introduction to the HIP HELPER Caregiver Workbook, which provides information on recovery, exercises, worksheets, and goal-setting plans to facilitate a ‘good’ recovery. After discharge, patients and caregivers will be supported in delivering rehabilitation through three telephone coaching sessions. Data, collected at baseline and four months post-randomization, will include: screening logs, intervention logs, fidelity checklists, quality assurance monitoring visit data, and clinical outcomes assessing quality of life, physical, emotional, adverse events, and resource use outcomes. The acceptability of the study intervention and RCT design will be explored through qualitative methods with 20 participants (patients and informal caregivers) and 12 health professionals.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
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
We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive. We retrospectively reviewed 170 patients who underwent 187 total hip arthroplasties at two hospitals with a minimum follow-up of ten years. All interventions were performed using the same combination of HXLPE cemented acetabular components with femoral stems made of titanium alloy. Kaplan-Meier survival analysis was performed for the primary endpoint of acetabular component revision surgery for any reason and secondary endpoint of the appearance of RLLs. RLLs that had appeared once were observed over time. We statistically assessed potential relationships between RLLs and a number of factors, including the technique of femoral head autografting and the Japanese Orthopaedic Association score.Aims
Methods
In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading. Torque-rotation curves were obtained from nine cadaveric hips to define the rotational restraint contributions of the capsular ligaments in 36 positions. A ligament model was developed to determine the line-of-action and effective moment arms of the medial/lateral iliofemoral, ischiofemoral, and pubofemoral ligaments in all positions. The functioning ligament forces and stiffness were determined at 5 Nm rotational restraint. In each position, the contribution of engaged capsular ligaments to the joint reaction force was used to evaluate the net force vector generated by the capsule.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.
The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA. A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis.Aims
Methods
The practice of overlapping surgery has been increasing in the delivery of orthopaedic surgery, aiming to provide efficient, high-quality care. However, there are concerns about the safety of this practice. The purpose of this study was to examine the safety and efficacy of a model of partially overlapping surgery that we termed ‘swing room’ in the practice of primary total hip (THA) and knee arthroplasty (TKA). A retrospective review of prospectively collected data was carried out on patients who underwent primary THA and TKA between 2006 and 2017 in two academic centres. Cases were stratified as partially overlapping (swing room), in which the surgeon is in one operating room (OR) while the next patient is being prepared in another, or nonoverlapping surgery. The demographic details of the patients which were collected included operating time, length of stay (LOS), postoperative complications within six weeks of the procedure, unplanned hospital readmissions, and unplanned reoperations. Fisher's exact, Wilcoxon rank-sum tests, chi-squared tests, and logistic regression analysis were used for statistical analysis.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
This combined clinical and in vitro study aimed to determine the incidence of liner malseating in modular dual mobility (MDM) constructs in primary total hip arthroplasties (THAs) from a large volume arthroplasty centre, and determine whether malseating increases the potential for fretting and corrosion at the modular metal interface in malseated MDM constructs using a simulated corrosion chamber. For the clinical arm of the study, observers independently reviewed postoperative radiographs of 551 primary THAs using MDM constructs from a single manufacturer over a three-year period, to identify the incidence of MDM liner-shell malseating. Multivariable logistic regression analysis was performed to identify risk factors including age, sex, body mass index (BMI), cup design, cup size, and the MDM case volume of the surgeon. For the in vitro arm, six pristine MDM implants with cobalt-chrome liners were tested in a simulated corrosion chamber. Three were well-seated and three were malseated with 6° of canting. The liner-shell couples underwent cyclic loading of increasing magnitudes. Fretting current was measured throughout testing and the onset of fretting load was determined by analyzing the increase in average current.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
High body mass index (BMI) is associated with increased rates of complications in primary total hip arthroplasty (THA), but less is known about its impact on cost. The effects of low BMI on outcomes and cost are less understood. This study evaluated the relationship between BMI, inpatient costs, complications, readmissions, and utilization of post-acute services. A retrospective database analysis of 40,913 primary THAs performed between January 2013 and December 2017 in 29 hospitals was conducted. Operating time, length of stay (LOS), complication rate, 30-day readmission rate, inpatient cost, and utilization of post-acute services were measured and compared in relation to patient BMI.Aims
Methods
The aim of this study was to report our experience at 3.5 years with outpatient total hip arthroplasty (THA). In this prospective cohort study, we included all patients who were planned to receive primary THA through the anterior approach between 1 April 2014 and 1 October 2017. Patient-related data and surgical information were recorded. Patient reported outcome measures (PROMs) related to the hip and an anchor question were taken preoperatively, at six weeks, three months, and one year after surgery. All complications, readmissions, and reoperations were registered.Aims
Methods
The primary aim of this study was to quantify the improvement in patient-reported outcome measures (PROMs) following total hip arthroplasty (THA), as well as the extent of any deterioration through the seven-year follow-up. The secondary aim was to identify predictors of PROM improvement and deterioration. A total of 976 patients were enrolled into a prospective, international, multicentre study. Patients completed a battery of PROMs prior to THA, at three months post-THA, and at one, three, five, and seven-years post-THA. The Harris Hip Score (HHS), the 36-Item Short-Form Health Survey (SF-36) Physical Component Summary (PCS), the SF-36 Mental Component Summary (MCS), and the EuroQol five-dimension three-level (EQ-5D) index were the primary outcomes. Longitudinal changes in each PROM were investigated by piece-wise linear mixed effects models. Clinically significant deterioration was defined for each patient as a decrease of one half of a standard deviation (group baseline).Aims
Patients and Methods
It is not known whether change in patient-reported outcome measures (PROMs) over time can be predicted by factors present at surgery, or early follow-up. The aim of this study was to identify factors associated with changes in PROM status between two-year evaluation and medium-term follow-up. Patients undergoing Birmingham Hip Resurfacing completed the Veteran’s Rand 36 (VR-36), modified Harris Hip Score (mHHS), Tegner Activity Score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at two years and a minimum of three years. A change in score was assessed against minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) thresholds. Binary logistic regression was used to assess the relationship between patient factors and deterioration in PASS status between follow-ups.Aims
Patients and Methods
The routine use of dual-mobility (DM) acetabular components in total hip arthroplasty (THA) may not be cost-effective, but an increasing number of patients undergoing THA have a coexisting spinal disorder, which increases the risk of postoperative instability, and these patients may benefit from DM articulations. This study seeks to examine the cost-effectiveness of DM components as an alternative to standard articulations in these patients. A decision analysis model was used to evaluate the cost-effectiveness of using DM components in patients who would be at high risk for dislocation within one year of THA. Direct and indirect costs of dislocation, incremental costs of using DM components, quality-adjusted life-year (QALY) values, and the probabilities of dislocation were derived from published data. The incremental cost-effectiveness ratio (ICER) was established with a willingness-to-pay threshold of $100 000/QALY. Sensitivity analysis was used to examine the impact of variation.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
Concurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients with spine fusions can increase the risk of dislocation risk after THA. We identified 84 patients (97 THAs) between 1998 and 2015 who had undergone spinal fusion prior to primary THA. Patients were stratified into three groups depending on the length of lumbar fusion and whether or not the sacrum was involved. Mean age was 71 years (40 to 87) and 54 patients (56%) were female. The mean body mass index (BMI) was 30 kg/m2 (19 to 45). Mean follow-up was six years (2 to 17). Patients were 1:2 matched to patients with primary THAs without spine fusion. Hazard ratios (HR) were calculated.Aims
Patients and Methods
It is important to consider sagittal pelvic rotation when introducing
the acetabular component at total hip arthroplasty (THA). The purpose
of this study was to identify patients who are at risk of unfavourable
pelvic mobility, which could result in poor outcomes after THA. A consecutive series of 4042 patients undergoing THA had lateral
functional radiographs and a low-dose CT scan to measure supine
pelvic tilt, pelvic incidence, standing pelvic tilt, flexed-seated
pelvic tilt, standing lumbar lordotic angle, flexed-seated lumbar
lordotic angle, and lumbar flexion. Changes in pelvic tilt from
supine-to-standing positions and supine-to-flexed-seated positions
were determined. A change in pelvic tilt of 13° between positions was
deemed unfavourable as it alters functional anteversion by 10° and
effectively places the acetabular component outside the safe zone
of orientation.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 acetabular labrum is a soft-tissue structure
which lines the acetabular rim of the hip joint. Its role in hip
joint biomechanics and joint health has been of particular interest
over the past decade. In normal hip joint biomechanics, the labrum
is crucial in retaining a layer of pressurised intra-articular fluid
for joint lubrication and load support/distribution. Its seal around
the femoral head is further regarded as a contributing to hip stability through
its suction effect. The labrum itself is also important in increasing
contact area thereby reducing contact stress. Given the labrum’s
role in normal hip joint biomechanics, surgical techniques for managing
labral damage are continuously evolving as our understanding of
its anatomy and function continue to progress. The current paper
aims to review the anatomy and biomechanical function of the labrum
and how they are affected by differing surgical techniques. Take home message: The acetabular labrum plays a critical role
in hip function and maintaining and restoring its function during
surgical intervention remain an essential goal. Cite this article:
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
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
To determine ten-year failure rates following 36 mm metal-on-metal
(MoM) Pinnacle total hip arthroplasty (THA), and identify predictors
of failure. We retrospectively assessed a single-centre cohort of 569 primary
36 mm MoM Pinnacle THAs (all Corail stems) followed up since 2012
according to Medicines and Healthcare Products Regulation Agency
recommendations. All-cause failure rates (all-cause revision, and
non-revised cross-sectional imaging failures) were calculated, with predictors
for failure identified using multivariable Cox regression.Aims
Patients and Methods
Many different designs of total hip arthroplasty
(THA) with varying performance and cost are available. The identification
of those which are the most cost-effective could allow significant
cost-savings. We used an established Markov model to examine the
cost effectiveness of five frequently used categories of THA which differed
according to bearing surface and mode of fixation, using data from
the National Joint Registry for England and Wales. Kaplan–Meier
analyses of rates of revision for men and women were modelled with
parametric distributions. Costs of devices were provided by the
NHS Supply Chain and associated costs were taken from existing studies.
Lifetime costs, lifetime quality-adjusted-life-years (QALYs) and
the probability of a device being cost effective at a willingness
to pay £20 000/QALY were included in the models. The differences in QALYs between different categories of implant
were extremely small (<
0.0039 QALYs for men or women over the
patient’s lifetime) and differences in cost were also marginal (£2500
to £3000 in the same time period). As a result, the probability
of any particular device being the most cost effective was very
sensitive to small, plausible changes in quality of life estimates
and cost. Our results suggest that available evidence does not support
recommending a particular device on cost effectiveness grounds alone.
We would recommend that the choice of prosthesis should be determined
by the rate of revision, local costs and the preferences of the
surgeon and patient. Cite this article:
We hypothesised that the synovial white blood cell (WBC) count
in patients with a late periprosthetic joint infection (PJI) of
the hip would depend on the duration of a patient’s symptoms, and
that the optimal diagnostic threshold would also depend on this
period of time. The synovial WBC count and percentage of polymorphonuclear cells
(%PMN), and the serum CRP and ESR levels obtained >
six weeks after
primary THA were compared between 50 infected and 88 non-infected
THAs, and in patients with symptoms for more than or less than two
weeks. Diagnostic thresholds for the synovial WBC count were calculated
using area under the curve calculation.Aims
Patients and 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:
The purpose of this study was to compare the long-term results
of primary total hip arthroplasty (THA) in young patients using
either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene
liner in terms of functional outcome, incidence of osteolysis, radiological
wear and rate of revision. We included all patients between the ages of 45 and 65 years
who, between January 2000 and December 2001, had undergone a primary
THA for osteoarthritis at our hospital using a CPE or HXLPE acetabular
liner and a 28 mm cobalt-chrome femoral head. From a total of 160 patients, 158 (177 hips) were available for
review (CPE 89; XLPE 88). The mean age, body mass index (BMI) and
follow-up in each group were: CPE: 56.8 years (46 to 65); 30.7 kg/m2 (19
to 58); 13.2 years (2.1 to 14.7) and HXLPE: 55.6 years (45 to 65);
BMI: 30 kg/m2 (18 to 51); 13.1 years (5.7 to 14.4).Aims
Methods
Revision total hip replacement (THR) for young
patients is challenging because of technical complexity and the potential
need for subsequent further revisions. We have assessed the survivorship,
functional outcome and complications of this procedure in patients
aged <
50 years through a large longitudinal series with consistent treatment
algorithms. Of 132 consecutive patients (181 hips) who underwent
revision THR, 102 patients (151 hips) with a mean age of 43 years
(22 to 50) were reviewed at a mean follow-up of 11 years (2 to 26)
post-operatively. We attempted to restore bone stock with allograft
where indicated. Using further revision for any reason as an end point,
the survival of the acetabular component was 71% ( This overall perspective on the mid- to long-term results is
valuable when advising young patients on the prospects of revision
surgery at the time of primary replacement. Cite this article:
The technical advances in arthroscopic surgery
of the hip, including the improved ability to manage the capsule
and gain extensile exposure, have been paralleled by a growth in
the number of conditions that can be addressed. This expanding list
includes symptomatic labral tears, chondral lesions, injuries of
the ligamentum teres, femoroacetabular impingement (FAI), capsular
laxity and instability, and various extra-articular disorders, including snapping
hip syndromes. With a careful diagnostic evaluation and technical
execution of well-indicated procedures, arthroscopic surgery of
the hip can achieve successful clinical outcomes, with predictable
improvements in function and pre-injury levels of physical activity
for many patients. This paper reviews the current position in relation to the use
of arthroscopy in the treatment of disorders of the hip. Cite this article:
Two-stage exchange remains the gold standard
for treatment of peri-prosthetic joint infection after total hip replacement
(THR). In the first stage, all components and associated cement
if present are removed, an aggressive debridement is undertaken
including a complete synovectomy, and an antibiotic-loaded cement
spacer is put in place. Patients are then treated with six weeks
of parenteral antibiotics, followed by an ‘antibiotic free period’
to help ensure the infection has been eradicated. If the clinical
evaluation and serum inflammatory markers suggest the infection
has resolved, then the second stage can be completed, which involves
removal of the cement spacer, repeat debridement, and placement
of a new THR. Cite this article:
Young adults with hip pain secondary to femoroacetabular
impingement (FAI) are rapidly being recognised as an important cohort
of orthopaedic patients. Interest in FAI has intensified over the
last decade since its recognition as a precursor to arthritis of
the hip and the number of publications related to the topic has
increased exponentially in the last decade. Although not all patients
with abnormal hip morphology develop osteoarthritis (OA), those
with FAI-related joint damage rapidly develop premature OA. There
are no explicit diagnostic criteria or definitive indications for
surgical intervention in FAI. Surgery for symptomatic FAI appears
to be most effective in younger individuals who have not yet developed
irreversible OA. The difficulty in predicting prognosis in FAI means
that avoiding unnecessary surgery in asymptomatic individuals, while
undertaking intervention in those that are likely to develop premature
OA poses a considerable dilemma. FAI treatment in the past has focused
on open procedures that carry a potential risk of complications. Recent developments in hip arthroscopy have facilitated a minimally
invasive approach to the management of FAI with few complications
in expert hands. Acetabular labral preservation and repair appears
to provide superior results when compared with debridement alone.
Arthroscopic correction of structural abnormalities is increasingly becoming
the standard treatment for FAI, however there is a paucity of high-level
evidence comparing open and arthroscopic techniques in patients
with similar FAI morphology and degree of associated articular cartilage damage.
Further research is needed to develop an understanding of the natural
course of FAI, the definitive indications for surgery and the long-term
outcomes. Cite this article:
There are several reports clarifying successful results following
open reduction using Ludloff’s medial approach for congenital (CDH)
or developmental dislocation of the hip (DDH). This study aimed
to reveal the long-term post-operative course until the period of
hip-joint maturity after the conventional surgical treatments. A long-term follow-up beyond the age of hip-joint maturity was
performed for 115 hips in 103 patients who underwent open reduction
using Ludloff’s medial approach in our hospital. The mean age at
surgery was 8.5 months (2 to 26) and the mean follow-up was 20.3
years (15 to 28). The radiological condition at full growth of the hip
joint was evaluated by Severin’s classification.Objectives
Methods
With greater numbers of younger patients undergoing
total hip replacement (THR), the effect of patient age on the diameter
of the femoral canal may become more relevant. This study aimed
to investigate the relationship between the diameter of the diaphysis
of the femoral canal with increasing age in a large number of patients
who underwent THR. A total of 1685 patients scheduled for THR had
their femoral dimensions recorded from calibrated radiographs. There
were 736 males and 949 females with mean ages of 67.1 years (34
to 92) and 70.2 years (29 to 92), respectively. The mean diameter
of the femoral canal was 13.3 mm (8.0 to 23.0) for males and 12.7
mm (6.0 to 26.0) for females. There was a poor correlation between
age and the diameter of the canal in males (r = 0.071, p = 0.05)
but a stronger correlation in females (r = 0.31, p <
0.001). The diameter of the femoral canal diameter of a female patient
undergoing THR could be predicted to increase by 3.2 mm between
the ages of 40 and 80 years, in contrast a male would be expected
to experience only a 0.6 mm increase during the same period. This
increase in the diameter of the canal with age might affect the
long-term survival of the femoral component in female patients. Cite this article:
While an increasing amount of arthroplasty articles
report comorbidity measures, none have been validated for outcomes.
In this study, we compared commonly used International Classification
of Diseases-based comorbidity measures with re-operation rates after
total hip replacement (THR). Scores used included the Charlson,
the Royal College of Surgeons Charlson, and the Elixhauser comorbidity
score. We identified a nationwide cohort of 134 423 THRs from the
Swedish Hip Arthroplasty Register. Re-operations were registered
post-operatively for up to 12 years. The hazard ratio was estimated
by Cox’s proportional hazards regression, and we used C-statistics
to assess each measure’s ability to predict re-operation. Confounding
variables were age, gender, type of implant fixation, hospital category,
hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant
relationship with increased risk of re-operation, with increased
scores for both one to two and three or more comorbidities. However,
the predictive C-statistic in this period for the Elixhauser score
was poor (0.52). None of the measures proved to be of any value between
two and 12 years. They might be of value in large cohort or registry
studies, but not for the individual patient. Cite this article:
The use of joint-preserving surgery of the hip
has been largely abandoned since the introduction of total hip replacement.
However, with the modification of such techniques as pelvic osteotomy,
and the introduction of intracapsular procedures such as surgical
hip dislocation and arthroscopy, previously unexpected options for
the surgical treatment of sequelae of childhood conditions, including
developmental dysplasia of the hip, slipped upper femoral epiphysis
and Perthes’ disease, have become available. Moreover, femoroacetabular
impingement has been identified as a significant aetiological factor
in the development of osteoarthritis in many hips previously considered to
suffer from primary osteoarthritis. As mechanical causes of degenerative joint disease are now recognised
earlier in the disease process, these techniques may be used to
decelerate or even prevent progression to osteoarthritis. We review
the recent development of these concepts and the associated surgical
techniques. Cite this article:
We investigated the rate of polyethylene wear of a cementless acetabular component at different periods of follow-up in order to test the hypothesis than an irrecoverable deformation process (creep) was followed by an initially low, but gradually increasing wear rate. We studied prospectively 93 uncemented total hip arthroplasties in 83 patients (mean age 50 years (22 to 63)) with a mean follow-up of 8.2 years (3 to 12). We measured the penetration of the femoral head from radiographs taken immediately after surgery at three, six and nine years, or at the latest follow-up. The median wear rate was 0.17 mm per year in the first three years, a finding which we considered to be caused by creep. Thereafter, the rate of wear declined to 0.07 mm per year (four- to six-year period) and then increased to 0.17 mm per year (seven to nine years) and 0.27 mm per year (more than nine years), which we considered to be a reflection of genuine polyethylene wear. After the nine-year follow-up the wear rates were higher in patients with marked osteolysis. We found no relationship between the inclination angle of the acetabular component or femoral head orientation and the rate of wear. No acetabular component required revision.
Between January 1998 and December 1998, 82 consecutive patients (86 hips) underwent total hip arthroplasty using a trabecular metal monoblock acetabular component. All patients had a clinical and radiological follow-up evaluation at six, 12 and 24 weeks, 12 months, and then annually thereafter. On the initial post-operative radiograph 25 hips had a gap between the outer surface of the component and the acetabular host bed which ranged from 1 to 5 mm. All patients were followed up clinically and radiologically for a mean of 7.3 years (7 to 7.5). The 25 hips with the 1 to 5 mm gaps were studied for component migration at two years using the Einzel-Bild-Roentgen-Analyse (EBRA) digital measurement method. At 24 weeks all the post-operative gaps were filled with bone and no acetabular component had migrated. The radiographic outcome of all 86 components showed no radiolucent lines and no evidence of lysis. No acetabular implant was revised. There were no dislocations or other complications. The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal.
We undertook a multicentre, prospective study of a series of 112 unstable trochanteric fractures in order to evaluate if internal fixation with a sliding screw device combined with augmentation using a calcium phosphate degradable cement (Norian SRS) could improve the clinical, functional and radiological outcome when compared with fractures treated with a sliding screw device alone. Pain, activities of daily living, health status (SF-36), the strength of the hip abductor muscles and radiological outcome were analysed. Six weeks after surgery, the patients in the augmented group had significantly lower global and functional pain scores (p <
0.003), less pain after walking 50 feet (p <
0.01), and a better return to the activities of daily living (p <
0.05). At follow-up at six weeks and six months, those in the augmented group showed a significant improvement compared with the control group in the SF-36 score. No other significant differences were found between the groups. We conclude that augmentation with calcium phosphate cement in unstable trochanteric fractures provides a modest reduction in pain and a slight improvement in the quality of life during the course of healing when compared with conventional fixation with a sliding screw device alone.
The aim of this study was to determine the accuracy
of registration and the precision of the resection volume in navigated
hip arthroscopy for cam-type femoroacetabular impingement, using
imageless and image-based registration. A virtual cam lesion was
defined in 12 paired cadaver hips and randomly assigned to either
imageless or image-based (three-dimensional (3D) fluoroscopy) navigated
arthroscopic head–neck osteochondroplasty. The accuracy of patient–image
registration for both protocols was evaluated and post-operative
imaging was performed to evaluate the accuracy of the surgical resection.
We found that the estimated accuracy of imageless registration in the
arthroscopic setting was poor, with a mean error of 5.6 mm (standard
deviation ( In conclusion, given the limited femoral surface that can be
reached and digitised during arthroscopy of the hip, imageless registration
is inaccurate and does not allow for reliable surgical navigation.
However, image-based registration does acceptably allow for guided
femoral osteochondroplasty in the arthroscopic management of femoroacetabular
impingement.
The creep and wear behaviour of highly cross-linked polyethylene and standard polyethylene liners were examined in a prospective, double-blind randomised, controlled trial using radiostereometric analysis. We randomised 54 patients to receive hip replacements with either highly cross-linked polyethylene or standard liners and determined the three-dimensional penetration of the liners over three years. After three years the mean total penetration was 0.35 mm (SD 0.14) for the highly cross-linked polyethylene group and 0.45 mm (SD 0.19) for the standard group. The difference was statistically significant (p = 0.0184). From the pattern of penetration it was possible to discriminate creep from wear. Most (95%) of the creep occurred within six months of implantation and nearly all within the first year. There was no difference in the mean degree of creep between the two types of polyethylene (highly cross-linked polyethylene 0.26 mm, SD 0.17; standard 0.27 mm, SD 0.2; p = 0.83). There was, however, a significant difference (p = 0.012) in the mean wear rate (highly cross-linked polyethylene 0.03 mm/yr, SD 0.06; standard 0.07 mm/yr, SD 0.05). Creep and wear occurred in significantly different directions (p = 0.01); creep was predominantly proximal whereas wear was anterior, proximal and medial. We conclude that penetration in the first six months is creep-dominated, but after one year virtually all penetration is due to wear. Highly cross-linked polyethylene has a 60% lower rate of wear than standard polyethylene and therefore will probably perform better in the long term.
We examined the morphology of mammalian hips asking whether evolution can explain the morphology of impingement in human hips. We describe two stereotypical mammalian hips, coxa recta and coxa rotunda. Coxa recta is characterised by a straight or aspherical section on the femoral head or head-neck junction. It is a sturdy hip seen mostly in runners and jumpers. Coxa rotunda has a round femoral head with ample head-neck offset, and is seen mostly in climbers and swimmers. Hominid evolution offers an explanation for the variants in hip morphology associated with impingement. The evolutionary conflict between upright gait and the birth of a large-brained fetus is expressed in the female pelvis and hip, and can explain pincer impingement in a coxa profunda. In the male hip, evolution can explain cam impingement in coxa recta as an adaptation for running.
Second-generation metal-on-metal bearings were introduced as a response to the considerable incidence of wear-induced failures associated with conventional replacements, especially in young patients. We present the results at ten years of a consecutive series of patients treated using a metal-on-metal hip resurfacing. A distinct feature of the bearings used in our series was that they had been subjected to double-heat treatments during the post-casting phase of their manufacture. In the past these bearings had not been subjected to thermal treatments, making this a unique metal-on-metal bearing which had not been used before in clinical practice. We report the outcome of 184 consecutive hips (160 patients) treated using a hybrid-fixed metal-on-metal hip resurfacing during 1996. Patients were invited for a clinicoradiological follow-up at a minimum of ten years. The Oxford hip score and anteroposterior and lateral radiographs were obtained. The mean age at operation was 54 years (21 to 75). A series of 107 consecutive hips (99 patients) who received the same prosthesis, but subjected to a single thermal treatment after being cast, between March 1994 and December 1995, were used as a control group for comparison. In the 1994 to 1995 group seven patients (seven hips) died from unrelated causes and there were four revisions (4%) for osteolysis and aseptic loosening. In the 1996 group nine patients died at a mean of 6.9 years after operation because of unrelated causes. There were 30 revisions (16%) at a mean of 7.3 years (1.2 to 10.9), one for infection at 1.2 years and 29 for osteolysis and aseptic loosening. Furthermore, in the latter group there were radiological signs of failure in 27 (24%) of the 111 surviving hips. The magnitude of the problem of osteolysis and aseptic loosening in the 1996 cohort did not become obvious until five years after the operation. Our results indicate that double-heat treatments of metal-on-metal bearings can lead to an increased incidence of wear-induced osteolysis.
The treatment of developmental dysplasia of the hip diagnosed after the first year of life remains controversial. A series of 36 children (47 hips), aged between one and 4.9 years underwent gradual closed reduction using the Petit-Morel method. A pelvic osteotomy was required in 43 hips (91.5%). The patients whose hips did not require pelvic osteotomy were among the youngest. The mean age at final follow-up was 16.1 years (11.3 to 32). The mean follow-up was 14.3 years (10 to 30). At the latest follow-up, 44 hips (93.6%) were graded as excellent or good according to the Severin classification. Closed reduction failed in only two hips (4.3%) which then required open reduction. Mild avascular necrosis was observed in one (2.1%). The accuracy of the reduction and associated low complication rate justify the use of the Petit-Morel technique as the treatment of choice for developmental dysplasia of the hip in patients aged between one and five years.
This study reviewed the results of a cementless anatomical femoral component to give immediate post-operative stability, and with a narrow distal section in order not to contact the femoral cortex in the diaphysis, ensuring exclusively metaphyseal loading. A total of 471 patients (601 hips) who had a total hip replacement between March 1995 and February 2002 were included in the study. There were 297 men and 174 women. The mean age at the time of operation was 52.7 years (28 to 63). Clinical and radiological evaluation were performed at each follow-up. Bone densitometry was carried out on all patients two weeks after operation and at the final follow-up examination. The mean follow-up was 8.8 years (5 to 12). The mean pre-operative Harris hip score was 41 points (16 to 54), which improved to a mean of 96 (68 to 100) at the final follow-up. No patient complained of thigh pain at any stage. No acetabular or femoral osteolysis was observed and no hip required revision for aseptic loosening of either component. Deep infection occurred in two hips (0.3%) which required revision. One hip (0.2%) required revision of the acetabular component for recurrent dislocation. Bone mineral densitometry revealed a minimal bone loss in the proximal femur. This cementless anatomical femoral component with metaphyseal loading but without distal fixation produced satisfactory fixation and encourages proximal femoral loading.
We identified five (2.3%) fractures of the stem in a series of 219 revision procedures using a cementless, cylindrical, extensively porous-coated, distally-fixed femoral stem. Factors relating to the patients, the implant and the operations were compared with those with intact stems. Finite-element analysis was performed on two of the fractured implants. Factors associated with fracture of the stem were poor proximal bone support (type III–type IV; p = 0.001), a body mass index >
30; (p = 0.014), a smaller diameter of stem (<
13.5 mm; p = 0.007) and the use of an extended trochanteric osteotomy (ETO 4/5: p = 0.028). Finite-element analysis showed that the highest stresses on the stem occurred adjacent to the site of the fracture. The use of a strut graft wired over an extended trochanteric osteotomy in patients lacking proximal femoral cortical support decreased the stresses on the stem by 48%. We recommend the use of a strut allograft in conjunction with an extended trochanteric osteotomy in patients with poor proximal femoral bone stock.
We report a retrospective review of the incidence of venous thromboembolism in 463 consecutive patients who underwent primary total hip arthroplasty (487 procedures). Treatment included both total hip replacement and hip resurfacing, and the patients were managed without anticoagulants. The thromboprophylaxis regimen included an antiplatelet agent, generally aspirin, hypotensive epidural anaesthesia, elastic compression stockings and early mobilisation. In 258 of these procedures (244 patients) performed in 2005 (cohort A) mechanical compression devices were not used, whereas in 229 (219 patients) performed during 2006 (cohort B) bilateral intermittent pneumatic calf compression was used. All operations were performed through a posterior mini-incision approach. Patients who required anticoagulation for pre-existing medical problems and those undergoing revision arthroplasty were excluded. Doppler ultrasonographic screening for deep-vein thrombosis was performed in all patients between the fourth and sixth post-operative days. All patients were reviewed at a follow-up clinic six to ten weeks after the operation. In addition, reponse to a questionnaire was obtained at the end of 12 weeks post-operatively. No symptomatic calf or above-knee deep-vein thrombosis or pulmonary embolism occurred. In 25 patients in cohort A (10.2%) and in ten patients in cohort B (4.6%) asymptomatic calf deep-vein thromboses were detected ultrasonographically. This difference was statistically significant (p = 0.03). The regimen followed by cohort B offers the prospect of a low incidence of venous thromboembolism without subjecting patients to the higher risk of bleeding associated with anticoagulant use.