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.

Purpose of the study: The pertinence of locking for major femoral revision remains a controversial issue. We conducted a retrospective multicentric study to assess the benefit and potential clinical and radiographic complications after using a long locked stem entirely coated with hydroxyapatite.

Material and methods: Our series included 77 patients (42 women, 35 men), mean age 71 years (range 34–90) reviewed at minimum one year. A modular implant was used; the long curved stem allowed total integration. Screws guaranteed distal locking. There were 71 revision THA on trochanteric-shaft fractures, three shaft nonunions, 34 aseptic loosenings, 9 septic loosening, 21 fractures on prosthesis, 6 implant failures and one instability. Seventy percent of patients had stage 3 and 4 bone lesions. Mean follow-up was 60 months.

Results: At last follow-up, 90% of patients were satisfied or very satisfied. The mean Harris function score improved from 32 to 83 and the PMA from 7 to 15. Sixty-four patients were pain free and 22% had pain solely under stress. There were 15 bone complications: dislocation (n=3), early infection (n=3 including 2 recurrences), implant failure (n=2), secondary femur fracture (n=5). Stem survival was 94% at nine years. Radiographically, total stem stability was noted in 73 patients (95%); instability was noted in four cases of fracture. Undeniable metaphyseal improvement was noted in 20% of cases, more modest improvement in 32%; the situation was considered unchanged in 31%. Locking was successful in all cases; cortical bone in contact with the locking screw was unchanged in 59 cases, slightly thickened in 16, including one case with a context of septic recurrence. The locking was dismantled in two cases (one empirically and one for pain), but the stem remained stable.

Discussion: Major damage to the femur can compromise stabilisation of the proximal or diaphyseal implants. Distal locking contributes to the initial mechanical stability, indispensable for secondary osteointegration of the implant. However, with total hydroxyapatite coating, rapid fixation in healthy zones is also crucial. Reconstruction of metaphyseal bone is not easy to quantify, but the absence of bone absorption is noteworthy.

Providing a long-lasting total hip arthroplasty for patients younger than 50 years remains one of the greatest challenges for modern arthroplasty surgery. Survival has been considered to be poor in young and active patients. We evaluated the benefit of total osteointegration of the prosthetic components in term of durable biological fixation.

This study concerns a prospective series of 113 patients operated between 1986 and 1994. The femoral component (Corail, Landos-DePuy) and the acetabular shells (Atoll & Tropic, Landos-Depuy) were totaly coated with a 150μ thick layer of pure HA following a plasma-spray process. The mean age at the time of surgery was 40.3 (range 17 to 49.8). Two patients are now deceased, 11 patients (9.7%) are lost to FU. The mean FU for 100 patients still on file is 14 years. AVN represents 29 % of the cohort, primary arthritis 22% and dysplasia 17%.

Functional results are excellent (mean PMA score 17.7 at the last control), as well as the subjective appreciation from the patients (94.9 % excellent or very good). 18 THA’s required components revisions: 6 without any implant removal (head or insert exchange); 1 stem (periprosthetic fracture) and 11 cups (6 well-fixed and 5 for loosening) were removed. Owing the high incidence of wear-related revision, actuarial survivorship, using re-operation for any reason as end-point, was 82% at 18 years ± 8.5, and considering aseptic loosening only, the survival probability of the stem is 99% ± 1.5 and 97 % ± 3.5.

It is clear that HA-coatings have given lesser performance in the cups than in the stems. We advocate for HA and the eradication of wear debris using hard on hard bearings. This combination seems to be a reasonable solution in this subgroup of young patients.

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.

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 Corail stems. Mean age of the patients was 64.5 years; 242 patients died (39%), 62 patients (10%) have been lost to follow-up. Mean follow-up of the 243 patients still alive was 17.7 years.

Results: 89 revisions: 72 acetabular cups, 8 bipolar, 9 stems. If we consider the survival of the stem alone, the Kaplan curve is 95.0% +/− 3.0, if we take into account only aseptic loosening, the probability of stem survival at 18 years is 98.9 +/− 1.

Discussion and Conclusions: At 18 years follow-up the fixation of a fully HA-COATED stem is still trustworthy. A major part of this prospective study was the lack of symptoms surrounding the prosthesis determined by X-ray imaging.

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 Corail stems showed highly satisfactory osseo-integration and fixation in 97.6% after a mean of 17.0 years follow-up.

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.