Aims. The aim of this study was to compare the mid-term patient-reported outcome, bone remodelling, and migration of a short stem (Collum Femoris Preserving; CFP) with a conventional uncemented stem (Corail). Methods. Of 81 patients who were initially enrolled, 71 were available at five years’ follow-up. The outcomes at two years have previously been reported. The primary outcome measure was the clinical result assessed using the Oxford Hip Score (OHS). Secondary outcomes were the migration of the stem, measured using radiostereometric analysis (RSA), change of bone mineral density (BMD) around the stem, the development of radiolucent lines, and additional patient-reported outcome measures (PROMs). Results. There were no statistically significant differences between the groups regarding PROMs (median OHS (CFP 45 (interquartile range (IQR) 35 to 48); Corail 45 (IQR 40 to 48); p = 0.568). RSA showed stable stems in both groups, with little or no further subsidence between two and five years. Resorption of the femoral neck was evident in nine patients in the CFP group and in none of the 15
Introduction: The
Purpose: The purpose of this study is to present our imaging results of
Introduction. The
The significance of periprosthetic fractures about a total hip arthroplasty (THA) is becoming increasingly important. Recent studies have demonstrated post-operative periprosthetic fracture rates are higher amongst cemented polished taper slip (PTS) stem designs compared to collared cementless (CC) designs. However, in the National Joint Registry, the rate of intra-operative periprosthetic femoral fractures (IOPFF) with cementless implant systems remains higher (0.87% vs 0.42%. p <0.001) potentially leading to more post-operative complications. This study identifies the incidence of IOPFF, the fracture subtype and compares functional outcomes and revision rates of CC femoral implants with an IOPFF to CC stems and PTS stems without a fracture. 5376 consecutive CC stem THA, carried out through a posterior approach were reviewed for IOPFF. Each fracture was subdivided into calcar fracture, greater trochanter (GT) fracture or shaft fracture. 1:1:1 matched analysis was carried out to compare Oxford scores at one year. Matching criteria included; sex (exact), age (± 1 year), American Society of Anaesthesiologists (ASA) grade (exact), and date of surgery (± 6 months). Electronic records were used to review revision rates. Following review of the CC stems, 44 (0.8%) were identified as having an IOPFF. Of these 30 (0.6%) were calcar fractures, 11 (0.2%) GT fractures and 3 (0.06%) were shaft fractures. There were no shaft penetrations. Overall, no significant difference in Oxford scores at one year were observed when comparing the CC IOPFF, CC non-IOPFF and PTS groups. There were no CC stems revised for any reason with either a calcar fracture or trochanteric fracture within the period of 8 years follow-up. IOPFF do occur more frequently in cementless systems than cemented. The majority are calcar and GT fractures. These fractures, when identified and managed intra-operatively, do not have worse functional outcomes or revision rates compared to matched non-IOPFF cases.
A longitudinal study was done assessing the latest radiographs available in a series of collarless
Safety and efficacy of novel prostheses relies on the determination of early implant migration and subsequent risk of loosening. Radiostereometric Analysis (RSA) has been used to evaluate the clinical failure risks of femoral stems by reporting distal migration, a measure of stem subsidence, when examining early migration characteristics. The migratory patterns of femoral stems, 24 months postoperatively, have provided a surrogate outcome measure to determine implant stabilisation and predict long-term performance and survivorship. RSA assessed femoral stem migration and provided comparison of the early migration characteristics with published data of a clinically established counterpart. Twenty five patients undergoing primary total hip arthroplasty were implanted with a hydroxyapatite-coated femoral stem. The median age was 65 years (range, 43–75 years). During surgery tantalum markers were attached onto the distal tip and shoulder of the stem. Eight tantalum markers were inserted into the femur, four placed in each of the greater and lesser trochanter. RSA examinations were performed postoperatively at 4 to 5 days, 6, 12 and 24 months. Eleven patients who had complete RSA follow-up as well as the valid data from five patients were analysed to determine the movement of the femoral stem relative to the femur and were compared to the published data of a clinically established counterpart.Background
Methods
Increasing femoral offset in total hip replacement (THR) has several benefits including improved hip abductor strength and enhanced range of motion. Biomechanical studies have suggested that this may negatively impact on stem stability. However, it is unclear whether this has a clinical impact. Using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), the aim of this study was to determine the impact of stem offset and stem size for the three most common cementless THR prostheses revised for aseptic loosening. The study period was September 1999 to December 2020. The study population included all primary procedures for osteoarthritis with a cementless THR using the Corail, Quadra-H and Polarstem. Procedures were divided into small and large stem sizes and by standard and high stem offset for each stem system. Hazard ratios (HR) from Cox proportional hazards models, adjusting for age and gender, were performed to compare revision for aseptic loosening for offset and stem size for each of the three femoral stems. There were 55,194
Aims. Highly polished stems with force-closed design have shown satisfactory clinical results despite being related to relatively high early migration. It has been suggested that the minimal thickness of cement mantles surrounding the femoral stem should be 2 mm to 4 mm to avoid aseptic loosening. The line-to-line cementing technique of the femoral stem, designed to achieve stem press-fit, challenges this opinion. We compared the migration of a highly polished stem with force-closed design by standard and line-to-line cementing to investigate whether differences in early migration of the stems occur in a clinical study. Methods. In this single-blind, randomized controlled, clinical radiostereometric analysis (RSA) study, the migration pattern of the cemented
We evaluated an anatomical uncemented stem, SP-CL, (Static Physiologicus – CementLess) designed to facilitate insertion and to avoid stress concentration at solitary contact points in a randomized controlled trial, with use of the
Aims. The
This study used model-based radiostereometric analysis (MBRSA) to compare migration of a recently introduced cementless hip stem to an established hip stem of similar design. Novel design features of the newer hip stem included a greater thickness of hydroxyapatite coating and a blended compaction extraction femoral broach. Fifty-seven patients requiring primary total hip arthroplasty (THA) were enrolled at a single centre. Patients were randomized to receive either an Avenir collarless stem and Trilogy IT cup (ZimmerBiomet) or a
The Norwegian Arthroplasty Register (NAR) started collecting data on total hip arthroplasty (THA) in 1987. Very long-term results of implants for THA are scarce. We aimed to show long-term results for the three most used femoral stems, operated from 1987. We included the uncemented
Aims. Cementless femoral stems must be correctly sized and well-seated to obtain satisfactory biological fixation. The change in sound that occurs during impaction of the femoral broach is said to indicate good fit, but this has not been widely studied. We set out to find whether the presence or absence of these sound changes could predict correct sizing. Patients and Methods. We recorded the sound generated during femoral broaching for 105 cementless total hip arthroplasties using the
Materials and methods: Based on data from the Norwegian Arthroplasty Register, we reviewed the results of uncemented femoral stems in Norway in the period 1987 to 1. April 2002. We compared these results to the results of the cemented Charnley monoblock stem, which still is the most commonly used femoral stem in Norway. Only prostheses used in more than one hundred hips were included. Based on these criteria, we identified a total of 7 856 primary total hip prostheses in fifteen different uncemented stems. With the Kaplan-Meier method, the survival of the primary prostheses were calculated and compared with each other and with the Charnley stem. The endpoint was revision in which the whole prostheses or the stem alone was removed or exchanged. The Cox regression analysis was used to adjust for differences in age, gender, diagnosis, former operations and profylactic antibiotics. Separate analyses for patients younger than 60 years and for stems with follow-up less than ten years were done. Reasons for revision in the uncemented
The aim of this study was to investigate the
relationship between the geometry of the proximal femur and the incidence
of intra-operative fracture during uncemented total hip arthroplasty
(THA). We studied the pre-operative CT scans of 100 patients undergoing
THA with an uncemented femoral component. We measured the anteroposterior
and mediolateral dimensions at the level of division of the femoral
neck to calculate the aspect ratio of the femur. Wide variations
in the shape of the femur were observed, from round, to very narrow
elliptic. The femurs of women were narrower than those of men (p
<
0.0001) and small femurs were also narrower than large ones.
Patients with an intra-operative fracture of the calcar had smaller
and narrower femurs than those without a fracture (p <
0.05)
and the implanted
We performed a case–control study to compare
the rates of further surgery, revision and complications, operating time
and survival in patients who were treated with either an uncemented
hydroxyapatite-coated Corail bipolar femoral stem or a cemented
Exeter stem for a displaced intracapsular fracture of the hip. The
mean age of the patients in the uncemented group was 82.5 years
(53 to 97) and in the cemented group was 82.7 years (51 to 99) We used
propensity score matching, adjusting for age, gender and the presence
or absence of dementia and comorbidities, to produce a matched cohort
receiving an Exeter stem (n = 69) with which to compare the outcome of
patients receiving a
Introduction: Uncemented total hip arthroplasty has evolved significantly over the past two decades. During this period many implants with different shapes, designs and coatings have developed and are being used with variable results. We present a series of 100 uncemented hip arthroplasties using the Duraloc 100 series cup and
Introduction. Bio-active fixation has increasingly gained acceptance over the last two decades. However extent of the coating is still a subject of debate. We introduced in 1986, the concept of total osteointegration of a tapered stem with the hope that we could achieve durable biological fixation while preserving normal periprosthetic bone trophicity. Material and methods. Patients from our first clinical series using this stem are now eligible for 18-year follow up. Between July 1986 and December 1990, we performed 615 THA using the
Bio-active fixation has increasingly gained acceptance over the last two decades. However extent of the coating is still a subject of debate. We introduced in 1986, the concept of total osteointegration of a tapered stem with the hope that we could achieve durable biological fixation while preserving normal periprosthetic bone trophicity. Patients from our first clinical series using this stem are now eligible for 18-year follow up. Between July 1986 and December 1990, we performed 615 THA using the
Introduction : Bio-active fixation has increasingly gained acceptance over the last two decades. However extent of the coating is still a subject of debate. We introduced in 1986, the concept of total osteointegration of a tapered stem with the hope that we could achieve durable biological fixation while preserving normal periprosthetic bone trophicity. Material and methods: Patients from our first clinical series using this stem are now eligible for 18-year follow up. Between July 1986 and December 1990, we performed 615 THA using the
Bio-active fixation has increasingly gained acceptance over the last two decades. However extent of the coating is still a subject of debate. We introduced in 1986, the concept of total osteointegration of a tapered stem with the hope that we could achieve durable biological fixation while preserving a normal periprosthetic bone trophicity. Patients from our first clinical series using this stem are now eligible for 18-year follow up. Between July of 1986 and December of 1990 we performed 615 total hip arthroplasties using the
Roentgen Stereophotogrammetric Analysis (RSA) is the gold standard for measuring implant micromotion thereby predicting implant loosening. Early migration has been associated with the risk of long-term clinical failure. We used RSA to assess the stability of the Australian designed cementless hip stem (Paragon TM) and now report our 5-year results. Fifty-three patients were prospectively and consecutively enrolled to receive a Paragon hip replacement. Tantalum beads were inserted into the bone as per RSA protocol and in the implant. RSA x-rays were taken at baseline 1–4 days post-surgery, at 6 weeks, 6 months, 12 months, 2 years, and 5 years. RSA was completed by an experienced, independent assessor. We reported the 2-year results on 46 hips (ANZJS 91 (3) March 2021 p398) and now present the 5-year results on 27 hips. From the 2-year cohort 5 patients had died, 8 patients were uncontactable, 1 patient was too unwell to attend, 5 patients had relocated too far away and declined. At 5 years the mean axial subsidence of the stem was 0.66mm (0.05 to 2.96); the mean rotation into retroversion was 0.49˚ (−0.78˚ to 2.09˚), rotation of the stem into valgus was −0.23˚ (−0.627˚ to 1.56˚). There was no detectable increase in subsidence or rotation between 6 weeks and 5 years. We compared our data to that published for the
Introduction. The results of cementless total hip arthroplasty (THA) vary with data from the UK national Joint Registry being less favourable than that from the Australian registry. The senior author started using a fully cementless THA in 2005 and we aimed to gauge the performance of the implants based on their revision data. Patients and methods. Between August 2005 and March 2015, 4,802 primary THA (4,309 patients) were performed with a cementless
Introduction. Primary fixation in uncemented Total Hip Replacement (THR) is achieved by implanting an appropriately sized stem. Last year, in our pilot study, we classified undersizing & reported the incidence of subsidence & radiolucent lines (RLL) in undersized uncemented stems. Now we report on a larger cohort of patients, reporting undersizing and its association with radiolucent lines and subsidence. Secondarily we report on the effect of using a collar, patients' BMI, and in a smaller group the five-year failure rate. Methods. A retrospective review of electronic records of 1337 cases who underwent THR using the
Introduction & aims. The magnitude and pattern of acceptable migration in clinically successful cementless stems is not well understood. Radiostereometric analysis (RSA) is a well-recognised method of assessing implant migration. Previous studies have reported long term RSA results for cemented stems. The aim of this study was to assess the long-term migration characteristics of the Corail hydroxyapatite-coated cementless stem at 10 years using RSA. Method. A prospective cohort of 30 patients undergoing primary total hip arthroplasty for primary hip osteoarthritis were enrolled into a study to characterise the migration behaviour of a cementless stem. Tantalum markers were attached to the stem and placed in the bone intraoperatively, allowing for RSA measurements to be taken in vivo. Previous 5-year results have been presented. A total of 14 patients (total 15 hips, one bilateral) with mean age 82 years (range, 69–92 years) underwent repeat long-term RSA radiographs at minimum 10 years post op. The mean time to follow up was 13.9 years (range, 13.3–14.4 years). The RSA radiographs were analysed to assess for implant rotation and translation. Results. None of the 14 patients (15 hips) followed up have been revised. The migration (rotation and translation) at 6 months, 1 year, 2 years, and 6 years has been described previously. No stems had additional subsidence of more than 0.25 mm between 6 months and 6 years. The resultant mean subsidence between 2 years and 6 years was 0.03 mm, which is below the limit measurable by RSA. The long-term, 10-year results, on implant rotation and translation will be presented. Conclusions. The
Introduction. Successful designs of total hip replacement need to be robust to surgery-related variability. Until recently, only simple parametric studies have explored the influence of surgical variability [1]. This study presents a systematic method for quantifying the effect of variability in positioning on the primary stability of femoral stems using finite element (FE) models. Methods. Patient specific finite element models were generated of two femurs, one male and one female. An automated algorithm positioned and sized a
Three basic design concepts of cementless femoral fixation have emerged. They include: anatomic designs, straight stem designs, and tapered designs. In addition, there have been modular designs. The most successful have been designs that have a metaphyseal sleeve with a tapered stem. A more recent newer concept has been the double taper neck designs which have not performed well in general. Anatomic Stem Designs: The rationale for an anatomic stem design was to design a component that matched the sagittal plane bow of the femur. The APR (Centerpulse, Austin, Texas) and the PCA (Howmedica, Rutherford, New Jersey) were the initial designs. Although these designs provided excellent micromotion stability, they are not used in their present length today because they could not fit in to all femurs. Straight Stem Designs: The concept of a straight stem design was to machine the femur to accept the prosthesis. This was done with diaphyseal reaming, proximal broaching, and preparing a proximal triangle to accommodate the proximal metaphyseal portion of the stem. These had previously, and still do, come in proximally coated and distally coated designs. They have proven to be durable long term. The AML fully coated stem (DePuy, Warsaw, Indiana) was and still is the prototype device. Tapered Stem Designs: The most popular designs today are the tapered stems. They are inserted either by a broach only, or ream and broach technique. Some only taper in the ML plane and are flat in the AP plane. These are called ML taper or blade devices (Taperloc and Trilock). These are usually inserted broach only. Some have a double taper with proximal fill and include the Zweymuller stem (Zimmer, Warsaw, Indiana), the Omnifit stem (Stryker, Mahwah, New Jersey), the Summit stem, and the
Introduction and Objectives: During 1986, we began working with the concept of osteointegration of a fully-coated stem in the hope of achieving a lasting fixation and preservation of normal trophic bone surrounding the prosthesis. Materials and Methods: Between July 1986 and December 1990, we implanted 615
The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group). The study included 36 patients with T-HA stems and 30 with N-HA stems. Dual-energy X-ray absorptiometry was used to measure the change in periprosthetic BMD, one and two years postoperatively. The 3D contact between the stem and femoral cortical bone was evaluated using a density-mapping system, and clinical assessment, including patient-reported outcome measurements, was recorded.Aims
Methods
Femoral stress shielding in cementless THA is a potential complication commonly observed in cementless distally loading press-fit stems. Long-term metaphyseal fixation and proximal load transfer is desired. Is routine autologous metaphyseal bone impaction and proximal primary stability an answer to this goal?. This prospective study describes long-term femoral bone remodeling and load transfer in cementless THA at a mean of 17 years (range: 15 to 20 years) in 208 consecutive fully HA-coated stems (Corail). All primary THA were performed by one group of surgeons between 1986 and 1991. The concept of surgical technique included impaction of autologous metaphyseal bone using bland femoral broaches until primary stability was achieved without distal press-fit. Radiographic evaluation revealed a total of five (2.4%) stems with periprosthetic osteolysis, which were associated with eccentric polyethylene wear. They were either revised or awaiting revision. The remaining 97.6% stems revealed desired proximal load transfer in the metaphysis (52%) or in both metaphysis and diaphysis (48%). Distal stress shielding was not observed and was considered to be related to: impaction of metaphyseal bone, bland broaches, HA coating, and prosthetic design. Biological autologous bone impaction of the metaphysis provides both primary stem stability and successful longterm osteointegration with the
Purpose Of Study. The study was started in 2004 to determine the best bearing surface in the long term, and to measure the metal ion levels generated by each of the bearing surfaces. We present the latest updated results. Material and methods. A prospective randomised study was started in 2004 to compare the wear characteristics of Ceramic on X linked Polyethylene (C.O.P.), Ceramic on Ceramic (C.O.C), Ceramic on Metal (C.O.M.) and Metal on Metal (M.O.M) bearings. The level of Cobalt and Chrome ions in red blood cells have been documented at serial intervals, using the ICP – MS method. Aside from the bearing surfaces the rest of the implant is standard, using a Pinnacle Cup,
We present a prospective study focused on radiographic long-term outcomes and bone remodeling at a mean of 17.0 years (range: 15 to 20) in 208 cementless fully HA-coated femoral stems (Corail®, DePuy, Johnson &
Johnson). Total hip replacements in this study were performed by three members of the surgeon design team (Artro Group) in France between 1986 and 1991. Radiographic evaluation focused on periprosthetic osteolysis, bone remodeling, osseous integration, subsidence, metaphyseal or diaphyseal load transfer, and femoral stress shielding. The radiographs were digitized and examined with contrast enhancing software (DICOM Anonymizer 1.1.2) for analysis of the trabecular architecture. Radiographic signs of aseptic stem loosening were visible in two cases (1%). Three stems (1.4%) showed metaphyseal periprosthetic osteolysis in two of seven Gruen zones associated with eccentric polyethylene wear awaiting metaphyseal bone grafting and cup liner exchange. One stem (0.5%) was revised due to infection. No stem altered in varus or valgus alignment more than two degrees and mean subsidence was 0.1 mm (range: 0 to 2) after a mean of 17.0 years. Five stems (2.4%) required or are awaiting revision surgery. Trabecular orientation and micro-anatomy suggested proximal load-transfer patterns in all except three cases (98.6%). Combined metaphyseal and diaphyseal osseo-integration and bone remodeling were visible in one hundred stems (48%). Diaphyseal stress shielding and cortical thickening were observed in three stems (1.4%). Other radiographic features are discussed in depth. This long-term study of 208 fully HA-coated
The February 2024 Hip & Pelvis Roundup360 looks at: Trial of vancomycin and cefazolin as surgical prophylaxis in arthroplasty; Is preoperative posterior femoral neck tilt a risk factor for fixation failure? Cemented versus uncemented hemiarthroplasty for displaced intracapsular fractures of the hip; Periprosthetic fractures in larger hydroxyapatite-coated stems: are collared stems a better alternative for total hip arthroplasty?; Postoperative periprosthetic fracture following hip arthroplasty with a polished taper slip versus composite beam stem; Is oral tranexamic acid as good as intravenous?; Stem design and the risk of early periprosthetic femur fractures following THA in elderly patients; Does powered femoral broaching compromise patient safety in total hip arthroplasty?
There has been no general agreement about the use of uncemented hip prostheses in patients with rheumatoid arthritis (RA). In the present study we compared the results for the cemented and uncemented stem that most commonly had been used in RA patients in the Norwegian Arthroplasty Register. MATERIAL AND Methods: All hospitals in the country participate and report their primary and revision operations of RA patients to the register. This group constitutes 3.5% of the patients in the register. For the present study we included primary prosthesis operations in RA patients during 1987–2005, where either the Corail or the Charnley stem, the most commonly used uncemented and cemented stems, had been used. We calculated survival by the Kaplan-Meier method and by Cox multiple regression with adjustment for age and gender. Results: The 10 years survival of the total hip prostheses were 81 % in the uncemented group and 89 % in the cemented group. However, the revisions of the uncemented prostheses were mainly performed due to cup problems. With revision of stem for any reason as end-point, the 10-year survival was 98% for the fully HA-coated uncemented
Background. It is unclear which form of anaesthesia is the most favourable in primary total hip replacement (THR) surgery. A recently published systematic review of modern anaesthesia techniques in primary THR surgery (Macfarlane 2009) was not able to show any convincing benefit of regional or general anaesthesia. One retrospective study that examined anaesthesia and leg length (Sathappan 2008), found an increased incidence of leg length difference > 5 mm in those patients who were operated with regional anaesthesia. Our department used a mini invasive approach in supine as standard procedure in THR. The type of anaesthesia that is chosen is up to the individual anaesthetist. Purpose. We wanted to see if there was any correlation between type of anaesthesia and leg length, total time spent in theatre and recovery room, postoperative hospital stay, blood loss or operating time in primary THR surgery with a mini invasive approach in supine. Materials and Methods. Our study was a retrospective study of 170 primary THR patients. All patients received an uncemented
Osteointegration of HA coated devices is well demonstrated. An abundant experimental material exists, allowing to describe the various properties of HA (early osteointegration, sealing effect, gap healing effect, etc…). Various side-effects have been described (third body wear of HA debris, delamination of the proximal coating etc…). Thus controversy still exists, despite a more and more convincing clinical experience. The role of human retrievals is therefore crucial to determine the exact role of all these parameters in the natural life of the implant throughout the years. 49 human well-functioning explants have been retrieved during systemic autopsies in elderly patients previously operated for a displaced fracture of the neck with a Corail® implant. Delays of implantation vary from 5 days to 10 years. All these specimens have been processed for optical microscopy, electronic microscopy with backscattering. This constitutes the longest report on one single implant and the retrievals are evenly distributed over this ten-year period. Several histomorphometric parameters were measured in the different Gruen’s zones: cortical bone density, cortical bone thickness, density of endosteal bone. 3 steps are recognized:. Bone formation around the implant appears early after surgery. Multiple units of bone formation go to coalescence as soon as 6 weeks and develop thereafter, leading to osteointegration. Bone remodelling reorganizes the architecture of connecting trabeculae according to the mechanical stresses resulting from the presence of the implant. Compression areas are generally the seat of broad and interconnected trabeculae, whereas tensile stresses areas display the presence of long, thin, unconnected and often parallel trabeculae. Very broad and short trabeculae are often seen at the level of the corners. Coating resorption is seen in every specimen beyond one year of implantation, predominantly in the areas with less bone coverage. Release of HA particles in the joint cavities was never encountered. Some metallic particles, originating from the femoral ball are commonly seen in the polyethylene. HA particles (presumably scratched off the prosthesis during insertion?...) have never been identified in the heterotopic ossifications. We conclude that the osteointegration of the
Introduction: There are ongoing concerns regarding metal wear debris following the use of metal-on-metal (MonM) bearings for hip surface and total arthroplasty. A Type IV Hypersensitivity reaction to MonM articulations has previously been identified (aseptic lymphocyte dominated vasculitis associated lesion, ALVAL) but little is known of its incidence, diagnosis or management. Persisting groin pain in MonM patients may be undiagnosed ALVAL. At our single centre we have reviewed and compared three types of MonM articulations to examine the incidence of ALVAL and to identify trends. Methods: The resurfacing group comprised 250 patients with the ASR prosthesis. In the resurfacing hybrid total hip replacement (THR) group there were 86 patients implanted with an ASR head on a stem. The final group comprised of 625 patients with a MonM THR using a 36mm Pinnacle head. Both the S-ROM and the
Introduction: There are ongoing concerns regarding metal wear debris following the use of metal-on-metal (MonM) bearings for hip surface and total arthroplasty. A Type IV Hypersensitivity reaction to MonM articulations has previously been identified (aseptic lymphocyte dominated vasculitis associated lesion, ALVAL) but little is known of its incidence, diagnosis or management. Persisting groin pain in MonM patients may be undiagnosed ALVAL. At our single centre we have reviewed and compared three types of MonM articulations to examine the incidence of ALVAL and to identify trends. Methods: The resurfacing group comprised 250 patients with the ASR prosthesis. In the resurfacing hybrid total hip replacement (THR) group there were 86 patients implanted with an ASR head on a stem. The final group comprised of 625 patients with a MonM THR using a 36mm Pinnacle head. Both the S-ROM and the
Aim of the study was to analyse the modifications of the pre-op and post-op femoral off-set after cementless total hip replacement. During an 18-month period, from January 2015 to June 2016, we retrospectively analysed data of 79 (n = 81 hips) patients (M:F = 31:48), with an average age of 70.38 yrs ± 10.05, who consecutively affered to our Department and underwent cementless total hip replacement for primary osteoarthritis with Pinnacle Gription. TM. cup and
“Get It Right First Time” (GIRFT) and NHS England’s Best Practice Tariff (BPT) have published directives advising that patients over the ages of 65 (GIRFT) and 69 years (BPT) receiving total hip arthroplasty (THA) should receive cemented implants and have brought in financial penalties if this policy is not observed. Despite this, worldwide, uncemented component use has increased, a situation described as a ‘paradox’. GIRFT and BPT do, however, acknowledge more data are required to support this edict with current policies based on the National Joint Registry survivorship and implant costs. This study compares THA outcomes for over 1,000 uncemented Corail/Pinnacle constructs used in all age groups/patient frailty, under one surgeon, with identical pre- and postoperative pathways over a nine-year period with mean follow-up of five years and two months (range: nine months to nine years and nine months). Implant information, survivorship, and regular postoperative Oxford Hip Scores (OHS) were collected and two comparisons undertaken: a comparison of those aged over 65 years with those 65 and under and a second comparison of those aged 70 years and over with those aged under 70.Aims
Methods
Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening. In all, ten hips in ten patients with PPRP with fixed pelvic obliquity who underwent THA as per an algorithmic approach in two centres from January 2014 to March 2018 were followed-up for a minimum of two years (2 to 6). All patients required one or more additional soft tissue procedures in a pre-determined sequence to correct the pelvic obliquity. All were invited for the latest clinical and radiological assessment.Aims
Methods
The aim of this study was to evaluate the survival of a collarless, straight, hydroxyapatite-coated femoral stem in total hip arthroplasty (THA) at a minimum follow-up of 20 years. We reviewed the results of 165 THAs using the Omnifit HA system in 138 patients, performed between August 1993 and December 1999. The mean age of the patients at the time of surgery was 46 years (20 to 77). Avascular necrosis was the most common indication for THA, followed by ankylosing spondylitis and primary osteoarthritis. The mean follow-up was 22 years (20 to 31). At 20 and 25 years, 113 THAs in 91 patients and 63 THAs in 55 patients were available for review, respectively, while others died or were lost to follow-up. Kaplan-Meier analysis was performed to evaluate the survival of the stem. Radiographs were reviewed regularly, and the stability of the stem was evaluated using the Engh classification.Aims
Methods
Hip arthroplasty aims to accurately recreate joint biomechanics. Considerable attention has been paid to vertical and horizontal offset, but femoral head centre in the anteroposterior (AP) plane has received little attention. This study investigates the accuracy of restoration of joint centre of rotation in the AP plane. Postoperative CT scans of 40 patients who underwent unilateral uncemented total hip arthroplasty were analyzed. Anteroposterior offset (APO) and femoral anteversion were measured on both the operated and non-operated sides. Sagittal tilt of the femoral stem was also measured. APO measured on axial slices was defined as the perpendicular distance between a line drawn from the anterior most point of the proximal femur (anterior reference line) to the centre of the femoral head. The anterior reference line was made parallel to the posterior condylar axis of the knee to correct for rotation.Aims
Methods
The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components. Patients were randomized to receive one of the two femoral components (Avenir or Corail) during their primary total hip arthroplasty between August 2018 and September 2020. Radiostereometric analysis examinations at six, 12, and 24 months were used to assess the migration of each implanted femoral component compared to a baseline assessment. Patient-reported outcome measures were also recorded for these same timepoints. Overall, 50 patients were enrolled (62% male (n = 31), with a mean age of 65.7 years (SD 7.3), and mean BMI of 30.2 kg/m2 (SD 5.2)).Aims
Methods
Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem.Aims
Methods
Femoral offset restoration is related to low rates of wear and dislocation. Replication of the native hip anatomy improves prosthesis survival, whereas increasing the femoral offset elevates the torque stresses, thus inducing a risk of suboptimal stem fixation. Although the Corail (DePuy Synthes, St Priest, France) uncemented stem has an excellent record of fixation, an unexpectedly number of aseptic loosenings has been noted in our institution. We sought to characterize the clinical parameters observed in a group of patients who have experienced metaphyseal aseptic loosenings with the collarless version of the Corail uncemented femoral component; describe the radiographic findings in this group of patients; expose the intraoperative findings in the cases that needed revision surgery and to calculate a possible frequency of this complication. We present a series of 15 metaphyseal debondings of the collarless version of the
Introduction. Complication and revision rates have shown to be high for all metal-on-metal (MoM) bearings, especially for the ASR Hip System (ASR hip resurfacing arthroplasty (HRA) and ASR XL total hip arthroplasty (THA)). This prompted the global recall of the ASR Hip System in 2010. Many studies have previously explored the association between female gender and revision surgery MoM HRA implants; yet less research has been dedicated to exploring this relationship in MoM THA. The first purpose of this study was to assess the associations between gender and implant survival, as well as adverse local tissue reaction (ALTR), in patients with MoM THA. Secondly, we sought to report the differences between genders in metal ion levels and patient reported outcome measures (PROMs) in patients with MoM THA. Methods. The study population consisted of 729 ASR XL THA patients (820 hips) enrolled from September 2012 to June 2015 in a multicenter follow-up study at a mean of 6.4 (3–11) years from index surgery. The mean age at the time of index surgery was 60 (22–95) years and 338 were women (46%). All patients enrolled had complete patient and surgical demographic information, blood metal ion levels and PROMs obtained within 6 months, and a valid AP pelvis radiograph dating a maximum of 2 years prior to consent. Blood metal ion levels and PROMs were then obtained annually after enrollment. A sub-set of patients from a single center had annual metal artifact reduction sequence (MARS) MRI performed and were analyzed for the presence of moderate-to-severe ALTR. Results. Eighty-nine hips (11%) were revised during the study period. Forty-five of the 338 men underwent revision (13%), and 44 of the 391 women underwent revision (11%). The mean time from index surgery to revision was 7 years for both males and females. After controlling for confounding variables, the only variables found to be associated with revision surgery in patients with unilateral THA were VAS pain (hazard ratio [HR], 1.28; p < 0.001) and elevated cobalt metal ion levels (HR, 1.02; p < 0.001). Patients with bilateral arthroplasties with low HHS (HR, 0.96; p < 0.001) and high cobalt levels (HR, 1.02; p < 0.001) were at increased risk for revision. Moderate-to-severe ALTRs were identified in 48 of the 133 hips with MARS MRI (36%), 17 of which were in females (30% of females) and 31 in males (40% of males). The only variables found to be associated with the presence of moderate-to-severe ALTR were abduction angle (HR, 0.92; p = 0.004) and
Introduction. Primary stability is essential for long-term performance of cementless femoral components. There is debate as to whether collars contribute to primary stability. The results from experimental studies and finite element (FE) analysis have been variable and contradictory. Subtle differences in performance are often swamped by variation between cadaveric specimens in vitro, whereas FE studies tend to be performed on a single femur. However, FE studies have the potential to make comparisons of implant designs within the same cohort of femurs, allowing for subtle performance differences to be identified if present. This study investigates the effect of a collar on primary stability of a femoral prosthesis across a representative cohort of femurs. Materials and Methods. FE models were generated from QCT scans of eight cadaveric femurs taken from the Melbourne Femur Collection (4 male and 4 female; BMI: 18.7 – 36.8 kg.m-2; age: 59 – 80 years) which were of joint replacement age. Heterogeneous bone material properties were assigned based on the CT greyscale information. Each femur was implanted with the collared and collarless version of
The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach. Patients were randomized to either a collared (n = 23) or collarless (n = 26) cementless femoral stem implanted using the DA approach. Canal fill ratio (CFR) was measured on the first postoperative radiographs. Patients underwent a supine radiostereometric analysis (RSA) exam postoperatively on the day of surgery and at two, four, six, 12, 26, and 52 weeks postoperatively. Patient-reported outcome measures (Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the 12-item Short Form Health Survey Mental and Physical Score, and University of California, Los Angeles (UCLA) Activity Score) were measured preoperatively and at each post-surgery clinic visit. Activity and function were also measured as the weekly average step count recorded by an activity tracker, and an instrumented timed up-and-go (TUG) test in clinic, respectively.Aims
Methods
Purpose: Exposure to polyethylene debris and bearing wear is a common feature of total hip prosthesis inserted with or without cement. Osteolysis depends on the number of particles involved and their size. This continuous series of total hip arthroplasties using a Corail prosthesis with 12 years follow-up was studied to assess the course of osteolysis around the prosthesis and the resistance of hydroxyapatite coated implants to the aggression of wear debris. Material and methods: One hundred fifteen patients underwent total hip arthroplasty in 1989 with a Corail prosthesis implanted by the same operator with a metal backed cup and a polyethylene insert. Mean age at implantation was 65 years. Review radiograms were available for 80 patients (38 women and 42 men). Twenty-seven patients had died, five answered a phone interview and three were lost to follow-up. The follow-up was 12 years and analysis was performed on the population with review data and x-rays. Results: There was no case with a loosened stem and none of the patients underwent revision. Twelve cups were however revised for loosening with granuloma. Polyethylene insert wear was seen in 62% of the cases. There was a relationship between the amount of wear debris and the extent of the gramulomas on the femur. These granulomas were basically observed in zones I and VII. Bone defects were curetted and filled with grafts for the 12 cup revisions. The cup bearing was changed in young patients. Good bone healing was a constant finding on follow-up x-rays. Discussion: Hydroxyapatite coated prostheses exhibit good long-term resistance to wear debris which causes osteolysis since none of the
This study aimed to evaluate implant survival of reverse hybrid
total hip arthroplasty (THA) at medium-term follow-up. A consecutive series of 1082 THAs in 982 patients with mean follow-up
of 7.9 years (5 to 11.3) is presented. Mean age was 69.2 years (21
to 94). Of these, 194 (17.9%) were in patients under 60 years, 663
(61.3%) in female patients and 348 (32.2%) performed by a trainee.
Head size was 28 mm in 953 hips (88.1%) or 32 mm in 129 hips (11.9%).
Survival analysis was performed and subgroups compared using log
rank tests.Aims
Patients and Methods
The aim of this study was to estimate the 90-day risk of revision for periprosthetic femoral fracture associated with design features of cementless femoral stems, and to investigate the effect of a collar on this risk using a biomechanical A total of 337 647 primary total hip arthroplasties (THAs) from the United Kingdom National Joint Registry (NJR) were included in a multivariable survival and regression analysis to identify the adjusted hazard of revision for periprosthetic fracture following primary THA using a cementless stem. The effect of a collar in cementless THA on this risk was evaluated in an Aims
Materials and Methods
The aim of this retrospective audit was to determine the route of referral or presentation of patients requiring revision following primary total hip arthroplasty (THA). A total of 4802 patients were implanted with an Orthopaedic Data Evaluation Panel (ODEP) 10A* cementless implant (Corail/Pinnacle) between 2005 and 2015; 80 patients with a mean age of 67.8 years (Aims
Patients and Methods
The aim of this study was to determine whether the rates of revision
for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle
components varied according to the year of the initial operation,
and compare these with the rates of revision for other designs of
MoM THA. Data from the National Joint Registry for England and Wales included
36 mm MoM THAs with Pinnacle acetabular components which were undertaken
between 2003 and 2012 with follow-up for at least five years (n
= 10 776) and a control group of other MoM THAs (n = 13 817). The
effect of the year of the primary operation on all-cause rates of revision
was assessed using Cox regression and interrupted time-series analysis.Aims
Patients and Methods
To determine whether there is any association between glomerular
filtration rate (GFR) and blood cobalt (Co) and chromium (Cr) levels
in patients with metal-on-metal (MoM) hip arthroplasty. We identified 179 patients with a unilateral 36 mm diameter head
as part of a stemmed Summit-Pinnacle MoM hip arthroplasty. GFR was
calculated using the Modification of Diet in Renal Disease formula.Aims
Patients and Methods
National Institute of Clinical Excellence guidelines
state that cemented stems with an Orthopaedic Data Evaluation Panel
(ODEP) rating of >
3B should be used for hemiarthroplasty when treating
an intracapsular fracture of the femoral neck. These recommendations
are based on studies in which most, if not all stems, did not hold
such a rating. This case-control study compared the outcome of hemiarthroplasty
using a cemented (Exeter) or uncemented (Corail) femoral stem. These
are the two prostheses most commonly used in hip arthroplasty in
the UK. Data were obtained from two centres; most patients had undergone
hemiarthroplasty using a cemented Exeter stem (n = 292/412). Patients
were matched for all factors that have been shown to influence mortality
after an intracapsular fracture of the neck of the femur. Outcome
measures included: complications, re-operations and mortality rates
at two, seven, 30 and 365 days post-operatively. Comparable outcomes
for the two stems were seen. There were more intra-operative complications in the uncemented
group (13% This study therefore supports the use of both cemented and uncemented
stems of proven design, with an ODEP rating of 10A, in patients
with an intracapsular fracture of the neck of the femur. Cite this article:
Primary uncemented femoral stems reported to the Norwegian arthroplasty register between 1987 and 2005 were included in this prospective observational study. There were 11 516 hips (9679 patients) and 14 different designs of stem. Kaplan-Meier survival probabilities and Cox regression were used to analyse the data. With aseptic loosening as the end-point, all currently used designs performed excellently with survival of 96% to 100% at ten years. With the end-point as stem revision for any cause, the long-term results of the different designs varied from poor to excellent, with survival at 15 years ranging between 29% and 97%. Follow-up for longer than seven years was needed to identify some of the poorly-performing designs. There were differences between the
Ceramic-on-metal (CoM) is a relatively new bearing
combination for total hip arthroplasty (THA) with few reported outcomes.
A total of 287 CoM THAs were carried out in 271 patients (mean age
55.6 years (20 to 77), 150 THAs in female patients, 137 in male)
under the care of a single surgeon between October 2007 and October
2009. With the issues surrounding metal-on-metal bearings the decision
was taken to review these patients between March and November 2011,
at a mean follow-up of 34 months (23 to 45) and to record pain,
outcome scores, radiological analysis and blood ion levels. The
mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268
hips (95%) had mild/very mild/no pain, the mean angle of inclination
of the acetabular component was 44.8o (28o to
63o), 82 stems (29%) had evidence of radiolucent lines
of >
1 mm in at least one Gruen zone and the median levels of cobalt
and chromium ions in the blood were 0.83 μg/L (0.24 μg/L to 27.56 μg/L)
and 0.78 μg/L (0.21 μg/L to 8.84 μg/L), respectively. The five-year
survival rate is 96.9% (95% confidence interval 94.7% to 99%). Due to the presence of radiolucent lines and the higher than
expected levels of metal ions in the blood, we would not recommend
the use of CoM THA without further long-term follow-up. We plan
to monitor all these patients regularly. Cite this article:
The National Institute for Health and Clinical
Excellence (NICE) guidelines from 2011 recommend the use of cemented
hemi-arthroplasty for appropriate patients with an intracapsular
hip fracture. In our institution all patients who were admitted
with an intracapsular hip fracture and were suitable for a hemi-arthroplasty
between April 2010 and July 2012 received an uncemented prosthesis
according to our established departmental routine practice. A retrospective
analysis of outcome was performed to establish whether the continued
use of an uncemented stem was justified. Patient, surgical and outcome
data were collected on the National Hip Fracture database. A total
of 306 patients received a Cathcart modular head on a Corail uncemented
stem as a hemi-arthroplasty. The mean age of the patients was 83.3
years ( Cite this article:
Periprosthetic femoral fractures (PFF) following total hip arthroplasty
(THA) are devastating complications that are associated with functional
limitations and increased overall mortality. Although cementless
implants have been associated with an increased risk of PFF, the
precise contribution of implant geometry and design on the risk
of both intra-operative and post-operative PFF remains poorly investigated.
A systematic review was performed to aggregate all of the PFF literature
with specific attention to the femoral implant used. A systematic search strategy of several journal databases and
recent proceedings from the American Academy of Orthopaedic Surgeons
was performed. Clinical articles were included for analysis if sufficient
implant description was provided. All articles were reviewed by
two reviewers. A review of fundamental investigations of implant
load-to-failure was performed, with the intent of identifying similar
conclusions from the clinical and fundamental literature.Aims
Patients and Methods
There is widespread concern regarding the incidence of adverse soft-tissue reactions after metal-on-metal (MoM) hip replacement. Recent National Joint Registry data have shown clear differences in the rates of failure of different designs of hip resurfacing. Our aim was to update the failure rates related to metal debris for the Articular Surface Replacement (ASR). A total of 505 of these were implanted. Kaplan-Meier analysis showed a failure rate of 25% at six years for the ASR resurfacing and of 48.8% for the ASR total hip replacement (THR). Of 257 patients with a minimum follow-up of two years, 67 (26.1%) had a serum cobalt concentration which was greater than 7 μg/l. Co-ordinate measuring machine analysis of revised components showed that all patients suffering adverse tissue reactions in the resurfacing group had abnormal wear of the bearing surfaces. Six THR patients had relatively low rates of articular wear, but were found to have considerable damage at the trunion-taper interface. Our results suggest that wear at the modular junction is an important factor in the development of adverse tissue reactions after implantation of a large-diameter MoM THR.
The purpose of this study was to evaluate whether an innovative
templating technique could predict the need for acetabular augmentation
during primary total hip arthroplasty for patients with dysplastic
hips. We developed a simple templating technique to estimate acetabular
component coverage at total hip arthroplasty, the True Cup: False
Cup (TC:FC) ratio. We reviewed all patients with dysplastic hips
who underwent primary total hip arthroplasty between 2005 and 2012.
Traditional radiological methods of assessing the degree of acetabular dysplasia
(Sharp’s angle, Tönnis angle, centre-edge angle) as well as the
TC:FC ratio were measured from the pre-operative radiographs. A
comparison of augmented and non-augmented hips was undertaken to
determine any difference in pre-operative radiological indices between
the two cohorts. The intra- and inter-observer reliability for all
radiological indices used in the study were also calculated.Aims
Patients and Methods
This was a randomised controlled trial studying
the safety of a new short metaphyseal fixation (SMF) stem. We hypothesised
that it would have similar early clinical results and micromovement
to those of a standard-length tapered Synergy metaphyseal fixation
stem. Using radiostereometric analysis (RSA) we compared the two
stems in 43 patients. A short metaphyseal fixation stem was used
in 22 patients and a Synergy stem in 21 patients. No difference
was found in the clinical outcomes pre- or post-operatively between
groups. RSA showed no significant differences two years post-operatively
in mean micromovement between the two stems (except for varus/valgus tilt
at p = 0.05) (subsidence 0.94 mm ( Cite this article:
There is little evidence on the cost effectiveness
of different brands of hip prostheses. We compared lifetime cost effectiveness
of frequently used brands within types of prosthesis including cemented
(Exeter V40 Contemporary, Exeter V40 Duration and Exeter V40 Elite
Plus Ogee), cementless (Corail Pinnacle, Accolade Trident, and Taperloc Exceed)
and hybrid (Exeter V40 Trilogy, Exeter V40 Trident, and CPT Trilogy).
We used data from three linked English national databases to estimate
the lifetime risk of revision, quality-adjusted life years (QALYs)
and cost. For women with osteoarthritis aged 70 years, the Exeter V40 Elite
Plus Ogee had the lowest risk of revision (5.9% revision risk, 9.0
QALYs) and the CPT Trilogy had the highest QALYs (10.9% revision
risk, 9.3 QALYs). Compared with the Corail Pinnacle (9.3% revision
risk, 9.22 QALYs), the most commonly used brand, and assuming a
willingness-to-pay of £20 000 per QALY gain, the CPT Trilogy is
most cost effective, with an incremental net monetary benefit of £876.
Differences in cost effectiveness between the hybrid CPT Trilogy
and Exeter V40 Trident and the cementless Corail Pinnacle and Taperloc
Exceed were small, and a cautious interpretation is required, given
the limitations of the available information. However, it is unlikely that cemented brands are among the most
cost effective. Similar patterns of results were observed for men
and other ages. The gain in quality of life after total hip arthroplasty,
rather than the risk of revision, was the main driver of cost effectiveness. Cite this article:
We report a multicentre prospective consecutive
study assessing the long-term outcome of the proximally hydroxyapatite
(HA)-coated ABG II monobloc femoral component in a series of 1148
hips in 1053 patients with a mean age at surgery of 64.77 years
(22 to 80) at a mean follow-up of 10.84 years (10 to 15.25). At
latest follow-up, the mean total Harris hip score was 94.7 points
( Cite this article:
Noise generation has been reported with ceramic-on-ceramic
articulations in total hip replacement (THR). This study evaluated
208 consecutive Delta Motion THRs at a mean follow-up of 21 months
(12 to 35). There were 141 women and 67 men with a mean age of 59
years (22 to 84). Patients were reviewed clinically and radiologically,
and the incidence of noise was determined using a newly described
assessment method. Noise production was examined against range of
movement, ligamentous laxity, patient-reported outcome scores, activity
level and orientation of the acetabular component. There were 143
silent hips (69%), 22 (11%) with noises other than squeaking, 17
(8%) with unreproducible squeaking and 26 (13%) with reproducible
squeaking. Hips with reproducible squeaking had a greater mean range
of movement (p <
0.001) and mean ligament laxity (p = 0.004), smaller
median head size (p = 0.01) and decreased mean acetabular component
inclination (p = 0.02) and anteversion angle (p = 0.02) compared
with the other groups. There was no relationship between squeaking
and age (p = 0.13), height (p = 0.263), weight (p = 0.333), body
mass index (p = 0.643), gender (p = 0.07) or patient outcome score
(p = 0.422). There were no revisions during follow-up. Despite the
surprisingly high incidence of squeaking, all patients remain satisfied
with their hip replacement. Cite this article:
Using data from the Norwegian Hip Fracture Register,
8639 cemented and 2477 uncemented primary hemiarthroplasties for
displaced fractures of the femoral neck in patients aged > 70 years
were included in a prospective observational study. A total of 218
re-operations were performed after cemented and 128 after uncemented
procedures. Survival of the hemiarthroplasties was calculated using
the Kaplan-Meier method and hazard rate ratios (HRR) for revision
were calculated using Cox regression analyses. At five years the
implant survival was 97% (95% confidence interval (CI) 97 to 97)
for cemented and 91% (95% CI 87 to 94) for uncemented hemiarthroplasties.
Uncemented hemiarthroplasties had a 2.1 times increased risk of
revision compared with cemented prostheses (95% confidence interval
1.7 to 2.6, p < 0.001). The increased risk was mainly caused
by revisions for peri-prosthetic fracture (HRR = 17), aseptic loosening
(HRR = 17), haematoma formation (HRR = 5.3), superficial infection
(HRR = 4.6) and dislocation (HRR = 1.8). More intra-operative complications,
including intra-operative death, were reported for the cemented
hemiarthroplasties. However, in a time-dependent analysis, the HRR
for re-operation in both groups increased as follow-up increased. This study showed that the risk for revision was higher for uncemented
than for cemented hemiarthroplasties.
The popularity of cementless total hip replacement
(THR) has surpassed cemented THR in England and Wales. This retrospective
cohort study records survival time to revision following primary
cementless THR with the most common combination (accounting for
almost a third of all cementless THRs), and explores risk factors independently
associated with failure, using data from the National Joint Registry
for England and Wales. Patients with osteoarthritis who had a DePuy
Corail/Pinnacle THR implanted between the establishment of the registry
in 2003 and 31 December 2010 were included within analyses. There
were 35 386 procedures. Cox proportional hazard models were used
to analyse the extent to which the risk of revision was related
to patient, surgeon and implant covariates. The overall rate of
revision at five years was 2.4% (99% confidence interval 2.02 to
2.79). In the final adjusted model, we found that the risk of revision
was significantly higher in patients receiving metal-on-metal (MoM:
hazard ratio (HR) 1.93, p <
0.001) and ceramic-on-ceramic bearings
(CoC: HR 1.55, p = 0.003) compared with the best performing bearing
(metal-on-polyethylene). The risk of revision was also greater for
smaller femoral stems (sizes 8 to 10: HR 1.82, p <
0.001) compared
with mid-range sizes. In a secondary analysis of only patients where body
mass index (BMI) data were available (n = 17 166), BMI ≥ 30 kg/m2 significantly
increased the risk of revision (HR 1.55, p = 0.002). The influence
of the bearing on the risk of revision remained significant (MoM:
HR 2.19, p <
0.001; CoC: HR 2.09,
p = 0.001). The risk of revision was independent of age, gender,
head size and offset, shell, liner and stem type, and surgeon characteristics. We found significant differences in failure between bearing surfaces
and femoral stem size after adjustment for a range of covariates
in a large cohort of single-brand cementless THRs. In this study
of procedures performed since 2003, hard bearings had significantly
higher rates of revision, but we found no evidence that head size
had an effect. Patient characteristics, such as BMI and American
Society of Anesthesiologists grade, also influence the survival
of cementless components. Cite this article:
An ongoing prospective study to investigate failing metal-on-metal
hip prostheses was commenced at our centre in 2008. We report on
the results of the analysis of the first consecutive 126 failed
mated total hip prostheses from a single manufacturer. Analysis was carried out using highly accurate coordinate measuring
to calculate volumetric and linear rates of the articular bearing
surfaces and also the surfaces of the taper junctions. The relationship
between taper wear rates and a number of variables, including bearing
diameter and orientation of the acetabular component, was investigated.Objectives
Methods