Introduction: The Corail stem is a well proven femoral implant used for the past 22 years. It is the most common uncemented femoral stem used for total hip replacements in the UK. The stem was modified in 2004 with an increased neck taper to allow for an increased range of bearings and modular heads. This study reviews a series of primary total hip replacements using this recently modified Corail stem to assess if this implant is still performing to acceptable standards. Method: A prospective patient database collated by 2 arthroplasty surgeons recorded data at the time of operation and subsequent follow up. All intra-operative and post-operative complications were recorded. Pre and postoperative oxford hip scores were analysed. Results: 751 cases were reviewed. The average age was 63 with females accounting for 69%. The pinnacle cup was used in 83% of cases, with a polyethylene bearing in 48%. Survival of the stem at 3 years was 99.9% (1 periprosthetic fracture following a fall), the cup 99.6%, with overall survival of 99.5%. The most common intra operative complication was calcar fracture occurring in 0.9%. Dislocation occurred in 0.5%, subsidence in 0.3%, deep infection in 0.1% and leg length discrepancy requiring shoe raise in 0.1%. Average 3 year oxford hip score was 12. Discussion: 3 year survival of both the femoral stem and the total hip replacement are above the quoted rates in the National Joint Registry’s 4th annual report for corail and uncemented stems (98.8% and 98.1% respectively), and also exceeds that of cemented stems (99.1%). The same report quotes similar rates of calcar fractures (0.8%), although we recorded no other perioperative complications. We conclude the new generation of Corail stem has excellent 3 year performance

Purpose: The purpose of this study is to present our imaging results of Corail stem implant after 11 years of follow-up. Material and Methods: 31 patients that underwent total hip arthroplasty between 1990–1996 in which Corail stem was implanted were included in this study. The imaging parameters that were collected from patient X-rays were: radiolucent line, osteolysis, subsidence, cortical hypertrophy, cortical thinning, undersizing, distal pod, rounded calcar, cupping and sagging. Results: Our of 31 patients, 21 were man and 10 were women, the mean age was 60.5 years (range 32–77y), 6 were bilateral, 3 patients had trochanteric osteotomy before surgery. The mean follow-up period was 8.2 years (range 5–11y). No sign of loosening were observed in any patient, 23 stems were implanted in neutral position, 2 stems in valgus and 6 in varus position. In 15 patients stem was undersized. In 23 patients distal pod was observed, 19 patients had trochanteric osteopenia, in 10 patients cupping was noticed and in 6 patients cortical thinning was observed. Five patients showed proximal osteopenia and in 5 patients sagging of few millimeters was noticed during the first years after surgery. No radiolucent line, osteolysis, subsidence and cortical hypertrophy were observed up to 11 years follow-up. Discussion: No signs of loosening were observed in all stems after 11 years of follow-up. Conclusion: In our opinion Corail stem for THA is a very reliable implant

Introduction. The Corail stem is a fully HA coated tapered implant that has demonstrated long-term success. On the NJR it has become one of the most commonly used implants in the UK. The aim of our study was to document our experience of the revision of this implant together highlighting some important technical considerations. Patients/Materials & Methods. A retrospective review of a consecutive case series of revision procedures where the Corail stem was extracted. We considered time since implantation, collared or uncollared design, indication for revision, Paprosky classification of femoral deficiency, endo-femoral reconstruction or extended approach/osteotomy, subsequent reconstruction either further primary type implant (cemented or cementless) or revision femoral implant. Results. 49 patients required extraction of Corial Stem as part of revision THA. Mean time to extraction 5.2 years (range 1.1 to 10.5 years). Indication for revision in 27 cases ARMD, 7 aseptic loosening, 7 PJI, 6 Peri-prosthetic fractures and 2 instability. The only cases that utilised an extended approach were those performed for peri-prosthetic fracture (5 B2 & 1 Type C fractures) all of which were reconstructed with a Modular Taper Fluted Stem. Of the remaining 43 cases revised for other reasons femoral bone stock was Paprosky Grade 2 in 21 cases, grade 3A in 22 cases. Stems were extracted with implant specific extraction device via endo-feomral route and subsequent reconstruction utilised a primary type femoral implant in 34% of cases. Discussion. All stems, apart from those revised for peri-prosthetic fracture were reconstructed via endo-femoral route. Safe implant extraction is key in this approach and the success of this method in our series emphasizes the major importance of the implant specific extraction instrumentation. Conclusion. As a result of safe implant extraction over 1/3. rd. of patients were able to have a primary implant inserted at the time of revision surgery

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 Corail uncemented stems which have reported survival rates of 95% at 20 years. Parameters scored included the degree of “Ghosting” or delamination, the Gruen, the stem fit in the femoral canal and the degree of calcar resorption. Patient and implant demographics were noted. At 3 years the loosening rate was 23% reaching 64% at 6 years after the index procedure. It was present in all age groups, with a peak in the 24 to 49 year age group. Males and females had the same occurrence. When it was present this was always in zone 1. It was present in 6% of patients in zone 7, but then always associated with zone 1 changes. High and standard off-set stems had the same loosening rates. The looser fit of the stem the higher the incidence of loosening. There was no correlation to the type of bearing surface or the degree of calcar resorption. Those patients with a BMI of 25 – 35 had lower loosening rates compared to those with higher or lower BMI's. We postulate that cancellous bone on-growth onto the hydroxyapatite coating associated with loading flexural micro-motion leads to hydroxyapatite being pulled off the smooth stem substrate in zone 1. Progressive delamination of the hydroxyapatite then occurs. The triple-tapered design though imparts continued stability. We report high loosening rates in the Corail stem and suggest a mechanism for its development

Background

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.

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 Corail stems, 13,642 Quadra-H stem, and 13,736 Polarstem prostheses included in this study. For the Corail stem, offset had an impact only when small stems were used (sizes 8-11). Revision for aseptic loosening was increased for the high offset stem (HR=1.90;95% CI 1.53–2.37;p<0.001). There was also a higher revision risk for aseptic loosening for high offset small size Quadra-H stems (sizes 0-3). Similar to the Corail stem, offset did not impact on the revision risk for larger stems (Corail sizes 12-20, Quadra-H sizes 4-7). The Polarstem did not show any difference in aseptic loosening revision risk when high and standard offset stems were compared, and this was irrespective of stem size. High offset may be associated with increased revision for aseptic loosening, but this is both stem size and prosthesis specific

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 Corail hip stem was compared between line-to-line and standard cementing in 48 arthroplasties. The primary outcome measure was femoral stem migration in terms of rotation and translation around and along with the X-, Y-, and Z- axes measured using model-based RSA at three, 12, and 24 months. A linear mixed-effects model was used for statistical analysis. Results. Results from mixed model analyses revealed a lower mean retroversion for line-to-line (0.72° (95% confidence interval (CI) 0.38° to 1.07°; p < 0.001), but no significant differences in subsidence between the techniques (-0.15 mm (95% CI -0.53 to 0.227; p = 0.429) at 24 months. Radiolucent lines measuring < 2 mm wide were found in three and five arthroplasties cemented by the standard and line-to-line method, respectively. Conclusion. The cemented Corail stem with a force-closed design seems to settle earlier and better with the line-to-line cementing method, although for subsidence the difference was not significant. However, the lower rate of migration into retroversion may reduce the wear and cement deformation, contributing to good long-term fixation and implant survival. Cite this article: Bone Joint J 2022;104-B(1):19–26

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 Corail stem as control. The SPÅ-Cl stem has been on the market since 2014 but is still not well documented. 79 patients (80 hips) were primarily recruited and 71 patients (72 hips, 36 SP-CL, 36 Corail) attended the last follow up at 2 years. The clinical evaluation included several types of PROMs with Oxford Hip Score (OHS) as primary outcome. In addition, repeated measurements of stem migration, changes in bone mineral density and development of radiolucencies were studied with RSA, DXA and conventional radiography. At two years the Oxford Hip Score did not differ between the SP-CL and Corail stem (estimated mean difference: −0.70 (95% CI: −4.28 – 2.89). In both groups Oxford hip score had almost doubled at 3 months, continued to increase up to 6 months and was about equal at 2 years (SP-CL; median 46 (17–48), Corail; median 47 (19–48)). At 2 years the SP-CL stems showed a median distal migration of −0.23 (−5.2 – 0.1) and the Corail stems of − 0.11 (−4.4 – 0.4). The SP-CL stems showed slightly more loss of bone mineral density in Gruen region 7 (p = 0.003). We found no difference in clinical results with use of either of the two stems. Bone mineral density loss tended to be higher with use of the SP-CL stem and the early subsidence tended to be more pronounced, which turned out to be compatible with about the same stem stability reached between 1 and 2 years. As a next step we think that the SP-CL stem should be studied in a multi-center setting, before accepted for general use

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 Corail collarless stem and Pinnacle cup (DePuy Synthes) via a posterior or lateral approach. Both stems are broach-only femoral bone preparation. RSA beads (Halifax Biomedical) were inserted into the proximal femur during surgery. Patients underwent supine RSA imaging a 6 weeks (baseline), 6, 12, and 24 months following surgery. The primary study outcome was total subsidence of the hip stem from baseline to 24 months as well as progression of subsidence between 12 and 24 months. These values were compared against published migration thresholds for well-performing hip stems (0.5mm). The detection limit, or precision, of MBRSA was calculated based on duplicate examinations taken at baseline. Patient reported outcome measures were collected throughout the study and included the Oxford-12 Hip Score (OHS), EuroQoL EQ-5D-5L, Hip Osteoarthritis Score (HOOS) as well as visual analogue scales (VAS) for thigh pain and satisfaction. Analysis comprised of paired and unpaired t-tests with significance set at p≤0.05. Forty-eight patients (30 males) were included for analysis; 7 patients received a non-study hip stem intra-operatively, 1 patient suffered a traumatic dislocation within three weeks of surgery, and 1 patient died within 12 months post-surgery. RSA data was obtained for 45 patients as three patients did not receive RSA beads intra-operatively. Our patient cohort had a mean age of 65.9 years (±;7.2) at the time of surgery and body mass index of 30.5 kg/m2 (±;5.2). No statistical difference in total stem migration was found between the Avenir and Corail stems at 12 months (p=0.045, 95%CI: −0.046 to 0.088) and 24 months (p=0.936, 95% CI: −0.098 to 0.090). Progression of subsidence from 12-24 months was 0.011mm and 0.034mm for the Avenir and Corail groups which were not statistically different (p=0.163, 95%CI: −0.100 to 0.008) between groups and significantly less than the 0.5mm threshold (pNo statistically significant differences existed between study groups for any pre-operative function scores (p>0.05). All patients showed significant functional improvement from pre- to post-surgery and no outcome measures were different between study groups with exception of EQ-5D-5L health visual analogue scale at 12 months which showed marginally superior (p=0.036) scores in the Avenir group. This study was not powered to detect differences in clinical outcomes. This study has demonstrated no statistical difference in subsidence or patient-reported outcomes between the Corail hip stem and the more recently introduced Avenir hip stem. This result is predictable as both stems are of a triple-tapered design, are coated with hydroxyapatite, and utilize a broach-only bone preparation technique. Both stem designs demonstrate migration below 0.5mm suggesting both are low-risk for aseptic loosening in the long-term

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 Corail femoral stem (n=66,309) and the cemented Exeter stem (n=35,050) both of which are currently in frequent use. In addition, we included the Charnley stem (n=32,578, in use until 2014). To ensure comparable conditions, stems fixated with low viscosity cement and stems revised due to infections were excluded. Differences in risk of revision (all reasons and stem revisions) were assessed with Kaplan-Meier and Cox regression analyses with adjustment for possible confounding from age, sex and diagnosis (OA, other). Stem revision was defined as a revision caused by loosening of the stem, dislocation, osteolysis in the femur, or periprosthetic femur fracture, and in which the femoral component was removed or exchanged. The median and max follow-up for Corail, Exeter and Charnley were 6.3 (33.1), 8.0 (34.2) and 13.1 (34.3) respectively. Thirty years survival estimates for Corail, Exeter and Charnley stems were 88.6% (CI:85.8–90.9%), 86.7% (83.7–89.2%) and 87.1% (85.4–88.5%) respectively with stem revision as endpoint, and 56.1% (CI:53.1–59.1%), 73.3% (70.5–76.1%) and 80.2% (78.4–82.0%) with all THA revisions as endpoint. Compared to the Corail, the Exeter (HRR=1.3, CI:1.2–1.4) and the Charnley (HRR=1.9, CI:1.7–2.1) had a significant higher risk of stem revision. Women 75 years and older had better results with the cemented stems. Analyses accounting for competing risk from other causes of revision did not alter the findings. The uncemented Corail stem performed well in terms of stem revisions for stem-related revision causes compared to two frequently used cemented stems with very long follow-up. The differences between the three stems were small

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 Corail stem and the cemented Charnley stem was analysed. Results: The Corail stem, wich is the most commonly used uncemented stem in Norway (n=3590), had excellent long term results. 10 years survival in patients younger than 60 years was for the Corail 97,5% and for the Charnley 90,2% (p=0,001). Reasons for revision of the Corail were in most cases pain and repeated dislocations. Aseptic loosening was the dominant cause of failure of the Charnley stem. Several uncemented stems have results which are as good as or superior to the Charnley. The Femora, the Biofit, the Parhofer and the Harris Galante stems all had inferior results. Many uncemented stems with less than 10-years of follow-up have excellent 5 years survival. The 10 years survival of uncemented total hip arthroplasties, however was inferior to the all-cemented Charnley. Cup revisions due to aseptic loosening, and wear and/or osteolysis were the reasons for this. Discussion: The Corail stem has excellent long term results. Several newer stems have promising short- and medium term results. Due to inferior results of unce-mented cups, however, most Norwegian orthopaedic surgeons use cemented primary hip replacements

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 Corail stems which have been in use at Merlin Park for the past 5 years and 1 year respectively. The CORAIL stem first introduced in 1986 has a triplanar wedge design for optimal metaphyseal fixation. The prosthesis is pointed in its distal part to allow centering in the medullary canal without cortical locking. The titanium stem is fully coated with a 150 micron thick layer of hydroyapatite. According to the Norwegian arthroplasty register the stem has 99.5% survival at 4.5 years (Havelin L1, Espheaug B, Vollset SE, Engesaeter LB). The Duraloc 100 series acetabular cups are hemispherical, porous-coated implants that are press fitted to a cavity reamed 2mm smaller than the cup diameter. Material and methods: Between January 2002 and September 2003 we carried out 100 uncemented THRs in 65 males and 35 female patients. Patients were deemed fit for uncemented hip replacement if they had good bone stock and had no co-morbid condition which might compromise bone quality. Preoperative work up was carried out to exclude any generalised diseases that might compromise bone quality, including bone density measurements where appropriate. Baseline WOMAC scores and Harris hip scores were performed pre-operatively and at latest follow up. Operative details were recorded along with post-operative complications. Patients were followed up clinically and radiologically for a period of 6 to 26 months. Results: There were 65 male patients and 35 female patients. Average age in men was 62.5 years (range 40 to 85 years) and in women was 65 years (range 48 to 86 years). Four patients had rheumatoid arthritis, the rest had osteoarthritis. The average post-op hospital stay was 12 days. The mean WOMAC score increased from 45 pre-op to 87 at the latest follow up. The average Harris hip score also increased from 52 pre-op to 92 at latest follow up. All procedures were either performed or directly supervised by the senior authors. Operations were performed through an antero-lateral approach, the femur was prepared first and a trial reamer was left in the femoral canal to minimise blood loss while the acetabulum was reamed. The average duration of surgery was 65 minutes (range 45 to 100 mins) and average intra-operative blood loss was 300mls (range 125 to 750mls). Intra-operative complications included 2 proximal femur stable split fractures, they were identified on table and fixed with circlage cables. Patients were allowed to mobilise partial weight bearing as tolerated. Complications included 4 deep venous thromboses, three superficial wound infections, one respiratory tract infection and one myocardial infarction. At the latest follow up there are no dislocations, no deep infections and no loosening of the cup or the stem. Discussion: When considering new implants and techniques in arthroplasty long term outcome of studies are necessary before any firm conclusions can be drawn regarding ultimate efficacy. This study however confirms that uncemented THRs using Duraloc cups and Corail stems is safe, involves minimal blood loss and gives good short term results. As there is no cement used, the duration of surgery is at least 15 to 20 mins less than an average cemented THR, which may be important when access to theatre is limited. The procedure is easy to learn and has well designed instrumentation. While there is no substitute for long term studies we feel that these early results are encouraging and justify continued work with the procedure in the context of a well designed prospective randomised trial comparing cemented and uncemented femoral components

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 Corail stem (DePuy). Corail is a straight tapered stem totally coated with a 150 μ thick layer of HA following an atmospheric plasma-spray process. The mean age at surgery was 64.5 (range 16 to 95). 242 patients are now deceased (39%), 62 patients (10%) are lost to follow-up. The mean follow-up for 243 living patients on file is 17.7 years. Results. 89 THAs required component revisions: 72 cups, 9 stems, 8 “cups and stems”. 8 cups and 4 stems have been revised for aseptic loosening. Owing to the high incidence of wear-related revision, Kaplan-Meïer survivorship at 18-year follow-up, using component revision for any reason as an endpoint, was 80.7 ± 3.3 (95% confidence intervals). In contrast, Corail stem survivorship, using stem removal for any reason as an endpoint, was 95.0% ± 3.0 at 18-year follow-up, and considering aseptic loosening only, the survival probability of the stem is 98.9% ± 1.1 at 18 years. Discussion and conclusions. Therefore, despite wear and proximal osteolysis, the fixation achieved with this totally HA-coated stem remained durable through 18-year follow-up. Regarding the periprosthetic remodelling during this period, modifications of the bone pattern have been strictly limited: slight resorption at the calcar level, absence of cortical hypertrophy, anecdotic significant stress-shielding. The radiological silence is one of the paramount facts demonstrated by this prospective study

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 Corail stem (DePuy). Corail is a straight tapered stem totally coated with a 150 μthick layer of HA following an atmospheric plasma-spray process. The mean age at surgery was 64.5 (range 16 to 95). 242 patients are now deceased (39%), 62 patients (10%) are lost to follow-up. The mean follow-up for 243 living patients on file is 17.7 years. Eighty nine THA’s required component revisions: 72 cups, 9 stems, 8 “cups and stems”. 8 cups and 4 stems have been revised for aseptic loosening. Owing to the high incidence of wear-related revision, Kaplan-Meïer survivorship at 18-year follow-up, using component revision for any reason as an endpoint, was 80.7 ± 3.3 (95% confidence intervals). In contrast, Corail stem survivorship, using stem removal for any reason as an endpoint, was 95.0% ± 3.0 at 18-year follow-up, and considering aseptic loosening only, the survival probability of the stem is 98.9% ± 1.1 at 18 years. Therefore, despite wear and proximal osteolysis, the fixation achieved with this totally HA-coated stem remained durable through 18-year follow-up. Regarding the periprosthetic remodelling during this period, modifications of the bone pattern have been strictly limited: slight resorption at the calcar level, absence of cortical hypertrophy, anecdotic significant stress-shielding. The radiological silence is one of the paramount facts demonstrated by this prospective study

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 Corail stem (DePuy). Corail is a straight tapered stem totally coated with a 150 μ thick layer of HA following an atmospheric plasma-spray process. The mean age at surgery was 64.5 (range 16 to 95). 242 patients are now deceased (39%), 62 patients (10%) are lost to follow-up. The mean follow-up for 243 living patients on file is 17.7 years. Results: 89 THA’s required component revisions: 72 cups, 9 stems, 8 “cups and stems”. 8 cups and 4 stems have been revised for aseptic loosening. Owing to the high incidence of wear-related revision, Kaplan-Meïer survivorship at 18-year follow-up, using component revision for any reason as an endpoint, was 80.7 ± 3.3 (95% confidence intervals). In contrast, Corail stem survivorship, using stem removal for any reason as an endpoint, was 95.0% ± 3.0 at 18-year follow-up, and considering aseptic loosening only, the survival probability of the stem is 98.9% ± 1.1 at 18 years. Discussion and Conclusions: Therefore, despite wear and proximal osteolysis, the fixation achieved with this totally HA-coated stem remained durable through 18-year follow-up. Regarding the periprosthetic remodelling during this period, modifications of the bone pattern have been strictly limited: slight resorption at the calcar level, absence of cortical hypertrophy, anecdotic significant stress-shielding. The radiological silence is one of the paramount facts demonstrated by this prospective study

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 Corail stem (DePuy). It is a straight tapered stem totally coated with a 150 μ thick layer of HA following an atmospheric plasma-spray process. The mean age at surgery was 64.5 (range 16 to 95 years) 242 patients are now deceased (39%), 62 (10%) patients are lost to follow-up. The mean follow-up for 243 living patients on file is 17.7years. 89 THAs required component revisions. 72 cup revisions were associated with wear and osteolysis. 8 cups and 4 stems have been revised for aseptic loosening. Owing to the high incidence of wear-related revision, Kaplan-Meïer survivorship at 18-year follow-up, using component revision for any reason as an endpoint, was 80.7±3.3 (95% confidence intervals). In contrast, Corail stem survivorship, using stem removal for any reason as an endpoint, was 95.0%±3.0 at 18-year follow-up, and considering aseptic loosening only, the survival probability of the stem is 98.9%±1.1 at 18 years. Therefore, despite wear and proximal osteolysis the fixation achieved with this totally HA-coated stem remained durable through 18-year follow-up. Regarding the periprosthetic remodelling during this period, modifications of the bone pattern have been strictly limited: slight resorption at the calcar level, absence of cortical hypertrophy, anecdotic significant stress-shielding. The radiological silence is one of the paramount facts demonstrated by this prospective study

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 Corail cementless stem and a similar pattern of migration was noted, however greater rotational stability was achieved with the Paragon stem over a comparable follow-up period. The RSA results confirm that any minor motion of the Paragon cementless stem occurs in the first 6 weeks after which there is sustained stability for the next 5 years. The combination of a bi-planar wedge and transverse rectangular geometry provide excellent implant stability that is comparable to or better than other leading cementless stems

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 Corail. ®. stem and a cementless Pinnacle. ®. cup. There were 2,086 (43.4%) males and 2,716 (56.6%) females with a median age of 70 years (IQR 13, Range 16–95). There were a number of changes to the surgical technique with respect to the Corail. ®. stem during the ten-year period, which we have categorised as phase 1 and phase 2. We compared the data in the two phases. Data were extracted from a prospectively maintained patient information database. Results. A total of 80 (1.67%) revisions have been performed to date (median follow-up 65.9 months, IQR 46.8, Range 0 to 121), which is equivalent to a cumulative revision risk of 2.5% at ten years. Revision rate was not significantly different in those less than 70 years old (1.63%) compared to those greater than or equal to 70 years old (1.76%, P=0.81). The leading causes of revision were instability (n=22, 0.46%), infection (n=20, 0.42%) and aseptic loosening of the stem (n=15, 0.31%). More collarless stems than collared stems have been revised. Phase 2 changes in surgical technique resulted in cessation of collarless stem use, a small but significant increase in mean stem size, and a paradoxical decrease in iatrogenic femoral fracture. Conclusions. The overall revision rates of the Corail. ®. stem and Pinnacle. ®. cup in this series are comparable to the best performing THA in equivalent registry data. Instability was the leading cause of revision but these data did not identify a causative factor. The changes in infection rate in this series are possibly influenced by changes in local antibiotic prophylaxis policy. There is a learning curve for the cementless stem as seen here by a reduction in revisions for aseptic loosening and iatrogenic femoral fracture during the ten-year period. We believe that collared stems, avoidance of undersizing and surgical technique focusing on primary stability are the key aspects

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 Corail stem was carried out. 1204 (Collared 1042, Uncollared 162) had a minimum follow up of 1 year, 693 of those had a follow up of at least 5 years. Radiological review was carried out by 2 independent investigators. Results. 19.77% stems were undersized. There was significantly higher incidence of subsidence & RLL in undersized stems with more than 1 year follow up. There no significant increase in incidence of RLL in those with BMI greater than 30 (16.88% vs 18.81%). Analysis of undersized collared stems demonstrated that even in this sub group undersizing is associated with increased incidence of RLL (P 0.00001) & subsidence (P 0.0003). A five year follow up, the revision rate for aseptic loosening of stem was 3.09% in undersized stems & 0.29% in appropriately sized stems (P 0.06). Conclusions. Our study indicates undersizing of uncemented stems is associated with poorer radiological outcomes & there's a trend of higher revision rate at 5 year follow up. This reinforces the importance of implanting appropriately sized stem, as undersizing can potentially compromise stem survival in uncemented total hip arthroplasty