Aims. 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. Methods. 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. Results. A total of seven stems (4.2%) were revised during the study period: one for aseptic loosening, three for periprosthetic fracture, two for infection, and one for recurrent dislocation. At 20 years, survival with revision of the stem for any indication and for aseptic loosening as the endpoint was 96.0% (95% confidence interval (CI) 92.6 to 99.5) and 98.4% (95% CI 96.2 to 100), respectively. At 25 years, the corresponding rates of survival were 94.5% (95% CI 89.9 to 99.3) and 98.1% (95% CI 95.7 to 99.6), respectively. There was radiological evidence of stable bony fixation in 86 stems (76.1%) and evidence of loosening in four (3.5%) at 20 years. All patients with radiological evidence of loosening were asymptomatic. Conclusion. The Omnifit HA femoral stem offered promising long-term survival into the third decade. Cite this article: Bone Joint J 2024;106-B(3 Supple A):110–114

Uncemented femoral components have been used in total hip arthroplasties (THAs) for over three decades. Data on long-term performance of hydroxyapatite-coated femoral stems is however limited. This study reports the survivorship of a collarless, straight, hydroxyapatite-coated femoral stem (Omnifit HA, Osteonic) with a minimum of 20 years of follow-up. We reviewed the results of 165 THAs using Omnifit HA in 138 patients performed between August 1993 and December 1999. The mean age at surgery was 46 years (range 20 – 77 years). Avascular necrosis was the most common cause of THA, followed by ankylosing spondylitis and primary osteoarthritis. The mean follow-up was 22 years (range 20–31 years). At 20 and 25 years, 113 arthroplasties (91 patients) and 63 arthroplasties (55 patients) were available for follow-up respectively, while others had deceased or were lost to follow-up. Kaplan-Meier survivorship analysis was performed to evaluate the survival of the femoral component. Radiographs were reviewed at regular intervals, and implant stability was evaluated using Engh classification. Seven out of 165 stems were revised upon the latest follow-up; that included one case of aseptic loosening with revision done at 15 years, three peri-prosthetic fractures, two infections, and one recurrent dislocation. At 20 years, survivorship with revision of the femoral stem for any cause and aseptic loosening as the endpoint was 96.0% (95% CI, 92.6 – 99.5%) and 98.4% (95% CI, 96.2 – 100%) respectively. At 25 years, the corresponding survivorship rates were 94.5% (95% CI, 91.9 – 97.3%) and 98.1% (95% CI, 95.7 – 99.6%) respectively. Radiographic findings of stable bony fixation were seen in 86 stems (76.1%) and those of loosening in 4 stems (3.5%) at 20 years. All patients with radiographic signs of loosening were asymptomatic and did not require revision. The Omnifit HA femoral stem offered promising long-term survivorship into the third decade

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. Methods. 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. Results. At 24 months the magnitude of migration of the femoral stem translations for the y axis of movement was 0.32 mm (range, 0.00 to 2.04 mm) (Figure 1). The data demonstrates that this migration of the femoral stem occurred primarily in the first 6 months postoperatively and that the migration characteristics exhibit a pattern of implant stabilisation between 6 and 24 months. At 24 months the magnitude of migration of the femoral stem rotations for the longitudinal y axis of movement was 0.60. o. (range, 0.08 to 2.08. o. ). The data demonstrates continuing migration of the femoral stem at 12 months postoperatively with early indications of implant stabilisation between 12 and 24 months. At 24 months the mean subsidence/distal migration of the femoral stem was 0.20 mm (range, −2.04 to 0.32 mm) (Figure 2). At 6 months, two patients (12.5%) exhibited subsidence greater than 0.50 mm with one demonstrating a mean subsidence of 2.00 mm. Between 6 and 24 months these two patients exhibited no more than 0.04 mm of subsidence (Figure 3). The mean retroversion rotation of the stem was 0.10. o. (range, −0.99 to 2.08. o. ). One patient rotated more than 2.00. o. into retroversion at 12 and 24 months postoperatively. Conclusions. In comparison the data demonstrates less stem subsidence and retroversion rotation than published data for a cementless hydroxyapatite-coated femoral stem when observing early migration characteristics. The magnitude and pattern of migration exhibited is indicative of good clinical outcomes and is comparable with a clinically established counterpart after short-term follow-up with RSA. These findings and comparisons highlight the early migration characteristics of a hydroxyapatite-coated femoral stem, however the analysis and comparison of the migratory pattern and characteristics over the mid-term follow-up will confirm implant stabilisation

INTRODUCTION. Cementless femoral component designs supplemented with hydroxyapatite (HA) coating have been hypothesised to enhance osseointegration, thereby improving stability and clinical outcomes. We herein offer interim results at 5 years from a prospective, multi-centre study of a femoral stem (SL-PLUS™ Hip Stem Prosthesis), forged from titanium alloy (Ti6Al7Nb) and consisting of a titanium plasma sprayed coating (0.3mm) with an additional 0.05mm layer of HA. METHODS. Investigators at 2 centres enrolled patients between 18–75 years of age who underwent primary total hip arthroplasty (THA) with this HA-coated stem. The study's primary outcome was the clinical efficacy of the stem, as measured by the Harris Hip Score (HHS), Western Ontario & McMaster Universities Osteoarthritis (WOMAC) Score calculated out of Hip Disability and Osteoarthritis Outcome Score (HOOS), and the EuroQol EQ-5D-3L index score and visual analogue scale (VAS). Its secondary outcomes included a radiographic assessment of implant position and fixation, and overall safety, as measured by intraoperative/early postoperative complications and survivorship calculated using Kaplan-Meier estimates. RESULTS. Ninety-three patients (94 hips) were enrolled in the study. At the time of surgery, the study population had a mean age of 60.1 years (standard deviation [SD], 8.4), a mean body mass index of 27.9 kg/m. 2. (SD, 4.75), and 54.8% were female. Indications for surgery include primary osteoarthritis (74.5%), dysplasia (17.5%), femoral head necrosis (6.4%), and other (2.1%). Patients were followed up through 5 years in the ongoing safety and performance analysis. Between preoperative baseline and final follow up, there were notable improvements in the mean scores for all primary clinical outcomes: HHS (51.6 to 91.4, respectively), WOMAC from HOOS (42.6 to 91.0, respectively), mean EQ-5D-3L index score (0.7 to 0.9, respectively), and EQ-5D-3L VAS (54.7 to 80.2, respectively). The majority of patients rated their satisfaction as excellent (84.2% of treated hips), with an additional 14.5% of treated hips being mostly satisfied. Five years after surgery, radiographic findings showed an overall stability of the device, with 100% unchanged stem positions (no movement in varus/valgus or subsidence) and no stem was classified as loose. Intraoperative complications were observed in 3 patients (3.2%), consisting of 2 cases of trochanteric fracture and 1 case of leg lengthening. There were no general early postoperative complications reported in any patient. Two revision surgeries of the study device were reported, both due to infection, resulting in a survivorship of 97.5% (95% confidence interval: 90.3% – 99.4%) at 5 years. CONCLUSION. These results confirm the safety and efficacy of this HA-coated femoral stem at 5 years. All clinical outcomes showed significant improvement between baseline and midterm follow up, with mean HHS in particular meeting the 90-point range considered “excellent.” Additionally, revision rates met the accepted benchmarks for a successful THA device. For any figures or tables, please contact authors directly

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

We performed a histological and histomorphometric examination in five cadaver specimens of the femoral and acetabular components and the associated tissue which had been recovered between 3.3 and 6.2 years after primary total hip arthroplasty (THA) using a proximal hydroxyapatite (HA)-coated titanium alloy implant. All had functioned well during the patients’ life.

All the stems were fixed in the femur and showed osseointegration of both the proximal and distal parts. The amount of residual HA was greatest in the distal metaphyseal sections, indicating that the rate of bone remodelling may be the main factor causing loss of HA. The level of activity of the patient was the only clinical factor which correlated with loss of coating. The percentage of bone-implant osseointegration was almost constant, regardless of the amount of HA residue, periprosthetic bone density or the time of implantation. HA debris was seldom observed and if present did not cause any adverse or inflammatory reaction. Partial debonding did occur in one case as a result of a polyethylene-induced inflammatory reaction.

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.

The Omnifit-HA femoral component has shown excellent results in early and mid-term industry sponsored multi-center clinical trials. To validate these results, an independent cohort of patients was followed prospectively for an average of ten years.

The senior author performed 103 consecutiveuncemented primary total hip arthroplasties in 89 patients from July 1991 to December 1996. The components implanted were the Omnifit-HA femoral stem and the Omnifit PSL porous coated acetabular shell. The cohort, with a mean ageat the time of the index procedure of 52 ± 9 years, was comprised of 45females and 58 males. The mean follow up was 10.3 years (range 7.3 – 12.7years). Two independent observers who were not part of the surgical team performed clinical and radiographic evaluations.

The senior author performed 103 consecutiveuncemented primary total hip arthroplasties in 89 patients from July 1991 to December 1996. The components implanted were the Omnifit-HA femoral stem and the Omnifit PSL porous coated acetabular shell. The cohort, with a mean ageat the time of the index procedure of 52 ± 9 years, was comprised of 45females and 58 males. The mean follow up was 10.3 years (range 7.3 – 12.7years). Two independent observers who were not part of the surgical team performed clinical and radiographic evaluations.

The Omnifit-HA femoral component continues to show excellent clinical results as indicated by the multi-center trials. This is the first study to report 10-year follow up by an independent surgeon. Despite the younger mean age, relatively high polyethylene wear, and 10% rate of lysis in the acetabulum, the femoral stem had a 100%survivorship. This supports the theory that proximal circumferential bone in growth affords protection against the migration of wear debris along the femoral stem.

Introduction

Achieving primary and long-term stability of femoral implant is critical for THA. This can be influenced by the shape and location of surface preparation as well as geometry. The Corail® stem has developed in 1986 in France, which is a straight quadrangular, and full HA coated standard titanium alloy stem featuring a metaphyseal tulip flare in combination with horizontal and vertical grooves. We have performed 75 THAs using it since May 2013. The purpose of this study was to evaluate radiographic changes of femur over time in Japanese patients after THA using this HA coated stem.

We describe the clinical and radiological outcome of 100 consecutive total hip replacements in 86 patients using the JRI Furlong hydroxyapatite-coated femoral component. The follow-up was 100% at a mean of ten years (9.0 to 12.0). All 54 living patients (62 hips) were examined annually. Their mean Merle d’Aubigné score was 5.8/5.6/4.6. A total of 32 patients had died. Their notes at the last annual assessment recorded a similar outcome to that of the living patients. Radiographs showed no radiolucent lines around any femoral component and there were no signs of impending failure. One patient required excision arthroplasty, but the femoral component had been bonded satisfactorily. There have been no other revisions of femoral components. Our findings suggest that the hydroxyapatite coating gives a satisfactory prosthesis-bone interface which is preferable to any other system.

Background: The standard fixation of femoral stems used for patients with femoral neck fractures is bone cement. Bone cement has side effects related to co-morbidity. The purpose of this study is to evaluate fixation, bone remodelling and clinical results with a new uncemented, fully hydroxyapatite-coated tapered femoral stem (Fracture Stem^®) designed for press-fit insertion in patients with femoral neck fractures.

Methods: Forty patients (25 women, 15 men) at a mean 82 (70–92) years of age with an acute displaced femoral neck fracture were included in the study. The patients were operated with the new stem and received a total hip arthroplasty. Tantalum markers were placed in the proximal femur during surgery. We have so far followed the patients for 1 year postoperatively with radiostereometric measurements, dual-energy x-ray absorptiometry and clinical evaluation including Harris hip score, pain numerical rating scale and health related quality of life.

Results: The stem showed good fixation. Subsidence and stem rotation for all stems but five were close to zero. Maximum total point motion increased above precision error at the 6 weeks follow-up but did not increase significantly after that. All stems with significant migration were stable after 3 months. We have had no per–or postoperative fracture. One stem has had to be revised because of a deep infection. Median bone loss after 6 months was significant (p=0.018 to 0.028) in all zones but Gruen zone 4. Bone loss was greatest in Gruen zone 1, 2, 6 and 7 with 29%, 22%, 18% and 32% loss respectively. Median Harris hip score decreased significantly (p=0.003) from 89 before fracture to 75 and 78 at the 6 weeks and 6 months follow-up. Pain numerical rating scale and Health related quality of life decreased until the 6 week visit but returned to prefracture value at 6 months.

Conclusions: According to these early 1-year results, Fracture Stem^® shows good fixation and fast ingrowth in osteoporotic bone. Periprosthetic bone loss due to stress-shielding was significant in all zones but zone 4. Clinically the stem behaved as expected. According to our results, we propose a randomized cinical trial in a larger patient population as the next step to evaluate this femoral stem.

Purpose: The purpose of this work was to assess the quality of the bone reconstruction in contact with the long hydroxyapatite-coated locked femoral stem used in a consecutive series of patients undergoing revision total hip arthroplasty (RTHA).

Material and methods: This series of 20 patients underwent RTHA for aseptic loosening (n=15) or septic loosening (n=5) of an AURA prosthesis. Mean age was 70.5 years. Mean time between insertion of the first stem and revision was 11 years for the aseptic patients and 2.6 years for the septic patients. Bony lesions of the femur were assessed with the SOFCOT classification: grade I=5, grade II=4, grade III=4, and grade IV=1. A transfemoral approach with a floating femoral segment was used in 14 patients and an endofemoral approach in six. The septic loosenings were reconstructed in two operative times in four patients and in one operation in one patient. An AURA reconstruction stem was used in 15 cases and a revision stem in five. A complementary cancellous bone graft with the endofemoral approach was used in six patients.

Results: Two patients died. All others were reviewed at a mean follow-up of 26 months (range 12–46 months) for clinical and radiographic assessment (five patients also had a supplementary scan at more than three years follow-up). We had three dislocations at 15 days with no recurrence and one case of sepsis at three months which cured after wash out and adapted antibiotics. All the femoral segments healed starting on the tenth week. The PMA score improved from 9.1 to 15.66 and the Harris score from 43.5 to 85.5. At last follow-up, all femoral lesions had moved to a lower SOFCOT score. There was a tight contact between the AURA stem and the femur on the last follow-up scan which showed an increase in the cortical index from 1 to 8 cm from the metaphyseal spine of the stem. None of the patients experienced secondary unlocking or required revision for a shorter stem.

Discussion: Revision after femoral failure with bone destruction using a non-cemented hydroxyapatite-coated stem allows immediate prosthetic mechanical stability and intimate bone reconstruction in the metaphyseal diaphyseal region. This reconstruction is real even if a graft is not used and appears to be favoured by the femorotomy. Implantation of the long stem is not particularly difficult and can even make the operation easier. Femorotomy has a real advantage, particularly for the revision of septic stems or in the event of difficult explantation.

Aims. 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). Methods. 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. Results. There were significantly larger contact areas in Gruen zones 3, 5, and 6 in the N-HA group than in the T-HA group. At two years postoperatively, there was a significant decrease in BMD around the proximal-medial femur (zone 6) in the N-HA group and a significant increase in the T-HA group. BMD changes in both groups correlated with BMI or preoperative lumbar BMD rather than with the extent of contact with the femoral cortical bone. Conclusion. The N-HA-coated stem showed a significantly larger contact area, indicating a distal fixation pattern, compared with the traditional fully HA-coated stem. The T-HA-coated stem showed better preservation of periprosthetic BMD, two years postoperatively. Surgeons should consider these patterns of fixation and differences in BMD when selecting fully HA-coated stems for THA, to improve the long-term outcomes. Cite this article: Bone Joint J 2024;106-B(6):548–554

Introduction. Appropriate prosthetic alignment is an important factor in maintaining stability and maximising the performance of the bearing after total hip replacement (THR). With a cementless component, the anteversion of the native femur has been shown to influence the anteversion of the prosthetic stem. However, the extent to which anteversion of a cementless stem can be adjusted from the native anteversion has seldom been reported. The aim of this study was to investigate the difference between native and stem anteversion with two different cementless stem designs. Method. 116 patients had 3-dimensional templating as part of their routine planning for THR (Optimized Ortho, Sydney). 96 patients from 3 surgeons (AS, JB, SM) received a blade stem (TriFit TS, Corin, UK) through a posterior approach. 18 patients received a fully HA-coated stem (MetaFix, Corin, UK) through a posterior approach by a single surgeon (WB). The anteversion of the native femoral neck was measured from a 3D reconstruction of the proximal femur. All patients received a post-operative CT scan which was superimposed onto the pre-op CT scan. The difference between native and achieved stem anteversion was then measured. As surgeons had differing philosophies around target stem anteversion, the differences amongst surgeons were also investigated. Results. On average, stems were implanted in less anteversion than native. The mean deviation between native and stem anteversion of the blade stems was −3.5° (−34.8° to 13.8°). The mean deviations of the three surgeons using the blade stem were −7.9° (−34.8° to 10.4°), −3.1° (−18.1° to 12.0°) and 2.7° (−8.9° to 13.8°). These were statistically significant, and represented a difference in philosophy around target anteversion amongst surgeons. The mean deviation between native and stem anteversion of the fully HA-coated stems was −6.5° (−24.6° to 9.2°). Conclusions. Cementless stem anteversion is not dictated by the native femoral anteversion. There were differences in target anteversion philosophies amongst surgeons and this was seen in the results. Surgical approach, proximal entry point, osteotomy angle, stem design and patient anatomy will all influence the ability to dictate cementless stem anteversion. The effect of these variables are the subject of on-going work

Aims: The purpose of this study is to compare the clinical outcome, radiological integration and survivorship associated with a porous coated stem and those associated with a hydroxyapatite-coated stem in a consecutive serie of uncemented total hip replacements. Methods: Between 1992 and 1995, 188 primary uncemented hip arthroplasties were performed at our institution using either a proximal porous-coat or a fully HA-coated stem. Mean age and weight and distribution of sex and primary diagnosis were similar in both groups. Ninety-eight hips from the HA group (group 1) and 69 from the porous-coated group (group 2) had a complete clinical and radiographic follow-up. The average duration of follow-up period for group 1 and 2 was 10.12 and 9.8 years respectively (range,9 to 12). Parameters such as implant migration and bone remodelling were especially evaluated and compared in both groups on postoperative X-rays. Results: In group 2 , 8 hips (11.8%) needed revision for aseptic loosening and 24 additional hips (34.7%) showed non-progressive lucent lines; distal migration of the stem was seen in 9 cases(13.04%). In contrast no hip in group 1 required revision and all but two hips in this group showed radiological integration; no stem showed distal migration. Harris hip score at follow-up was better in group 1 (p= 0.05) due to a higher incidence of thigh pain in group 2 (23% vs 0%). Significant differences between both groups (p=0.02) were also observed in predicted rate of survival at 10 years with revision for aseptic loosening as the endpoint. Conclusion: In our series the HA-coated stem has provided significantly better outcomes in terms of clinical scores, radiological integration and survivorship rates than porous-coated stem

Aims

BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems.

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?