Porous-coated Cup Research Articles

Distribución de la osteólisis periprotésica en la cadera. Estudio con resonancia magnética

Introduction Magnetic resonance imaging (MRI) is useful in assessing bone and soft tissue lesions due to the production of wear particles. Our objective was to study the distribution of lesions in patients with one type of cementless acetabular component with this technique. Material and methods We included 40 total hip arthroplasty with press-fitted hydroxyapatite porous-coated cup and multiple optional screw holes performed over a mean of 13 years. We studied the presence, extent and continuity of the granulomatous lesion and osteolysis with MRI using special pulse sequences to reduce metal artefacts. Results One hip was not amenable to analysis. An isolated granulomatous lesion was found in 3 hips, associated osteolysis in 32, in the pelvis only in 10, in the femur only in 3 and in both segments in 19. By zones, the pelvis involvement was supra-acetabular ilium in 15, ischium-pubic branch in 24, ischium in 12 and retro-acetabular ischium in 21. Only two hips and two screws central lesions were isolated from the granulomatous mass. Comments and conclusions MRI osteolysis and soft tissue lesions secondary to wear to be studied. The distribution of osteolytic areas show a peripheral pattern typical of non-perforated acetabular cups frequently coexisting with proximal femoral involvement, highlighting few isolated lesions in the holes or around the implanted screws.

Distribution of periprosthetic osteolysis in the hip: A study using magnetic resonance

Introduction Magnetic resonance imaging (MRI) is useful in assessing bone and soft tissue lesions due to the production of wear particles. Our objective was to study the distribution of lesions in patients with one type of cementless acetabular component with this technique. Material and methods We included 40 total hip arthroplasty with press-fitted hydroxyapatite porous-coated cup and multiple optional screw holes performed over a mean of 13 years. We studied the presence, extent and continuity of the granulomatous lesion and osteolysis with MRI using special pulse sequences to reduce metal artefacts. Results One hip was not amenable to analysis. An isolated granulomatous lesion was found in 3 hips, associated osteolysis in 32, in the pelvis only in 10, in the femur only in 3 and in both segments in 19. By zones, the pelvis involvement was supra-acetabular ilium in 15, ischium-pubic branch in 24, ischium in 12 and retro-acetabular ischium in 21. Only two hips and two screws central lesions were isolated from the granulomatous mass. Comments and conclusions MRI osteolysis and soft tissue lesions secondary to wear to be studied. The distribution of osteolytic areas show a peripheral pattern typical of nonperforated acetabular cups frequently coexisting with proximal femoral involvement, highlighting few isolated lesions in the holes or around the implanted screws.

The Results of a Press-Fit-Only Technique for Acetabular Fixation in Hip Dysplasia

The purpose of the present study was to evaluate the 6- to 11-year follow-up results of hemispherical porous-coated cups implanted into dysplastic hips using press-fit technique without screws focusing on the amount of host bone coverage. There were 87 patients who underwent 98 primary total hip arthroplasties. Bony coverage was measured as the angle between the vertical line and the line drawn from the cup center to the lateral edge of the acetabulum, which was named the cup center-edge angle (cup-CE angle). All 98 cups were judged to be bone ingrown. The minimum cup-CE angle was 8.4° (mean, 26.3°). Bone-cup contact of more than 8.4° of the cup-CE angle was large enough for press-fit cups to resist superior directed loads during this follow-up period.

Survivorship of Polyethylene Liner Exchanges Performed for the Treatment of Wear and Osteolysis Among Porous-Coated Cups

For the past 17 years, we have favored treating patients with polyethylene wear and osteolysis by performing a liner exchange with retention of the old shell when possible. Using our institutional database, we identified 187 acetabular revisions in which we had retained the old shell. Among this group, we found 25 rerevisions. These included 10 for hip instability, 9 for cup loosening, 3 for recurrence of excessive wear or osteolysis, 2 for infection, and 1 for dissociation of the replaced liner. The need for rerevision varied with the different retained shell designs. We rerevised 17% of the total hip arthroplasties with old spiked shells, 21% with Arthropor shells, 13% with Triloc shells and 5% with Duraloc shells. Before making a decision to retain or remove a well-fixed old acetabular shell, we recommend consideration of the design's past track record and careful inspection of the condition of the existing shell.

Ten-year results with the Morscher press-fit cup: an uncemented, non-modular, porous-coated cup inserted without screws

Total hip arthroplasty (THA) with well designed cementless acetabular implants has shown excellent results. The purpose of this study was to assess our clinical and radiological outcomes using an uncemented cup. We conducted a prospective cohort study including all consecutive primary THAs performed with the Morscher press-fit cup, an uncemented non-modular acetabular component, between March 1996 and December 1998. Patients were evaluated at ten years with clinical and radiological follow-up, patient satisfaction and questionnaire assessment using the Harris hip score (HHS), Merle d'Aubigné and Postel score, the UCLA score, the 12-item short-form health survey (SF-12) and a visual analog scale. Five hundred sixty-one THAs were performed in 518 patients. At 120 months (± 7.3 months), 303 patients with 335 THAs were still available for follow-up. None of the patients had required cup revision for aseptic loosening. At ten years, the cup survivorship was 98.8% (95% CI 97.4-99.5) with cup revision for any cause as an endpoint. No radiolucencies were seen around the cups, but osteolytic defects involved 21 stems (8.3%). Mean total linear polyethylene wear was 0.9 mm. The Morscher acetabular replacement cup provides excellent results at ten years. There were no revisions for aseptic loosening of the cup, and no osteolytic defects were found around the cup. Patient satisfaction was high and the clinical results were very good.

Bedding-in and true wear in two different generations cementless porous-coated acetabular cups

Radiographic measurement of polyethylene wear cannot distinguish between so-called bedding-in and true wear in porous-coated cups. In this study, sequential wear performance was compared in two different generations of two cementless porous-coated cups. Group 1 consisted of 42 Harris-Galante I cups (HG I; 32-mm femoral head) and 37 Harris-Galante II cups (HG II; 28 mm); group 2 comprised 30 ACS liners using Profile or Trilock cups (32 mm) and 53 Duraloc cups (28 mm). All liners were made of conventional polyethylene sterilised by gamma irradiation in air. All cups showed radiographic bone ingrowth. Follow-up ranged from 5 to 17 years. Anteroposterior pelvic radiographs were scanned digitally and sequential femoral head penetration was estimated using a software package based on Kim's method. Bedding-in was 0.17 ± 0.09 mm for HG I and 0.09 ± 0.02 for HG II cups (p=0.035) in group 1, and 0.60 ± 0.50 for the ACS liners and 0.11 ± 0.41 for the Duraloc cups (p<0.01) in group 2. Femoral head penetration at the end of follow-up was 1.50 ± 0.28 mm for HG I (mean 14 years) and 0.85 ± 0.01 for HG II (8 years) in group 1, and 2.86 ± 0.68 for ACS (12 years) and 0.90 ± 0.41 for Duraloc (8 years) in group 2. Mean wear was 0.09 mm/year for HG I and 0.10 for HG II in group 1, and 0.20 for the ACS liners and 0.09 for the Duraloc cups in group 2. In conclusion, sequential femoral head penetration using Kim's digitised method allows us to distinguish between bedding-in and true wear.

Bedding-in and true wear in two different generations cementless porous-coated acetabular cups

Radiographic measurement of polyethylene wear cannot distinguish between so-called bedding-in and true wear in porous-coated cups. In this study, sequential wear performance was compared in two different generations of two cementless porous-coated cups. Group 1 consisted of 42 Harris-Galante I cups (HG I; 32-mm femoral head) and 37 Harris-Galante II cups (HG II; 28 mm); group 2 comprised 30 ACS liners using Profile or Trilock cups (32 mm) and 53 Duraloc cups (28 mm). All liners were made of conventional polyethylene sterilised by gamma irradiation in air. All cups showed radiographic bone ingrowth. Follow-up ranged from 5 to 17 years. Anteroposterior pelvic radiographs were scanned digitally and sequential femoral head penetration was estimated using a software package based on Kim's method. Bedding-in was 0.17 ± 0.09 mm for HG I and 0.09 ± 0.02 for HG II cups (p=0.035) in group 1, and 0.60 ± 0.50 for the ACS liners and 0.11 ± 0.41 for the Duraloc cups (p<0.01) in group 2. Femoral head penetration at the end of follow-up was 1.50 ± 0.28 mm for HG I (mean 14 years) and 0.85 ± 0.01 for HG II (8 years) in group 1, and 2.86 ± 0.68 for ACS (12 years) and 0.90 ± 0.41 for Duraloc (8 years) in group 2. Mean wear was 0.09 mm/year for HG I and 0.10 for HG II in group 1, and 0.20 for the ACS liners and 0.09 for the Duraloc cups in group 2. In conclusion, sequential femoral head penetration using Kim's digitised method allows us to distinguish between bedding-in and true wear.

The Outcome of Polyethylene Liner Exchange for the Treatment of Wear and Osteolysis Among Porous-Coated Cups

The treatment of osteolysis associated with stable cementless cups remains controversial. This study evaluates the outcome of polyethylene liner exchanges performed for wear or osteolysis, which has been our preferred management strategy over the past 17 years.

A Comparison of Wear and Osteolysis for Two Cup Designs: A Retrospectively Matched Study

Although early outcome data from multiple centers have demonstrated that cross-linked polyethylene has substantially reduced total hip arthroplasty (THA) wear rates, some investigators have still reported retroacetabular osteolysis. To examine the role of cup design, we compared the incidence and size of osteolysis lesions among two hemispheric, porous-coated cup designs implanted with cross-linked Marathon polyethylene (DePuy) that incorporated different liner locking mechanisms. One design used a locking ring (Duraloc 100, DePuy) while the other had an interference taper locking mechanism (Pinnacle 100, DePuy).

Cementless total hip arthroplasty in patients with severely dysplastic hips and a previous Schanz osteotomy of the femur

Background and purpose Historically, a Schanz osteotomy of the femur has been used to reduce limp in patients with severely dysplastic hips. In such hips, total hip arthroplasty is a technically demanding operation. We report the long-term results of cementless total hip arthroplasty in a group of patients who had all undergone a Schanz osteotomy earlier.Patients and methods From 1988 through 1995, 68 total hip replacements were performed in 59 consecutive patients previously treated with a Schanz osteotomy. With the cup placed at the level of the true acetabulum, a shortening osteotomy of the proximal part of the femur and distal advancement of the greater trochanter were performed in 56 hips. At a mean of 13 (9–18) years postoperatively, we evaluated these patients clinically and radiographically.Results The mean Harris hip score had increased from 51 points preoperatively to 93 points. Trendelenburg sign was negative and there was good or slightly reduced abduction strength in 23 of 25 hips that had not been revised. There were 12 perioperative complications. Only 1 cementless press-fit porous-coated cup was revised for aseptic loosening. However, the 12-year survival rate of these cups was only 64%, as 18 cups underwent revision for excessive wear of the polyethylene liner and/or osteolysis. 6 CDH femoral components had to be revised due to technical errors.Interpretation Our results suggest that cementless total hip arthroplasty combined with a shortening osteotomy of the femur and distal advancement of the greater trochanter can be recommended for most patients with a previous Schanz osteotomy of the femur. Because of the high incidence of liner wear and osteolysÍs of modular cementless cups in this series, nowadays we use hard-on-hard articulations in these patients.

Computed Tomography Assessment of Pelvic Osteolysis and Cup-Lesion Interface Involvement with a Press-Fit Porous-Coated Acetabular Cup

We used computed tomography to investigate the 3-dimensional pattern of expansile osteolysis that occurs with a modular cementless acetabular component incorporating a central hole. We measured pelvic osteolysis volume and evaluated how much of the porous-coated surface area was involved with osteolytic defects. Among the 34 total hip arthroplasties we studied, osteolysis almost always originated from the dome hole and typically expanded inferiorly or superiorly without involving the anterior or posterior surfaces of the cup. Larger-volume lesions generally involved greater amounts of the cup surface area, but the cup-lesion interface involvement plateaued at 40% for radiographically stable cups without clinical complications. We hypothesize that the plateauing surface area involvement may explain the absence of cup loosening among these cases despite the presence of large osteolytic lesions.

Acetabular Fixation Options First-Generation Modular Cup Curtain Calls and Caveats

This study reviewed the outcome of a single institution's experience with 910 primary total hip arthroplasties using 3 different types of modular, first-generation, hemispheric porous-coated cups. The population included 433 Arthopor, 394 ACS Triloc+, and 83 Harris-Galante components. Among 168 total hip arthroplasties that have undergone acetabular revision, aseptic loosening has occurred in 20 cases. Using liner or cup revision for any reason as an end point, we found that 15-year survivorship was 74.9% ± 6.2% (95% confidence interval) for the Arthopor cups, 70.1% ± 7.0% for the ACS Triloc+ components, and 89.3% ± 10.3% for the Harris-Galante cups ( P = .02, log rank). Despite a high incidence of revision for polyethylene wear-related complications and occasional late porous–coating delamination, survivorship using revision for aseptic loosening as an end point exceeded 95% at 15 years for all 3 cup designs.

Clinical and radiographic results and wear performance in different generations of a cementless porous-coated acetabular cup

We compared clinical results and wear performance in two different generations of a cementless porous-coated cup, analysing the long-term results of 83 uncemented Harris-Galante I cups (32-mm femoral head) and 93 uncemented Harris-Galante II cups (28-mm femoral head). All polyethylene liners were gamma irradiated in air. Polyethylene linear wear was estimated using a software package. The minimum follow-up was 10 years. Nine Harris-Galante I cups and two Harris-Galante II cups were revised due to aseptic loosening or polyethylene problems. The mean femoral head penetration at 6 weeks after surgery was 0.15 +/- 0.05 mm for the Harris-Galante I cups and 0.12 +/- 0.03 for the Harris-Galante II cups (p < 0.001);but mean wear was 0.13 +/- 0.23 mm per year for the Harris-Galante I cups and 0.11 +/- 0.10 for the Harris-Galante II cups (p = 0.740). Most of the metallic shells in both groups showed stable fixation. The so-called second-generation cups had lower initial polyethylene wear that resulted in less polyethylene wear at the latest the follow-up, but the overall wear rate was similar in both groups despite the different femoral head sizes and the improved locking mechanism.

Bone Ingrowth into Harris-Galante Porous-Coated Acetabular Cup Retrieved during Revision

Bone Ingrowth into Harris-Galante Porous-Coated Acetabular Cup Retrieved during Revision

Porous-coated cups fixed with screws: A 12-year clinical and radiostereometric follow-up study of 50 hips

Background Excellent mid-term results have stimulated the use of hemispherical porous-coated cups in hip replacement. With longer follow-up, there have been problems related to polyethylene wear and liner fixation, and osteolysis has been documented in reports of selected cases. We evaluated the clinical and radiographic results of 50 patients followed for 12 years.Patients and methods 58 consecutive patients (58 hips), mean age 55 years, were operated with Harris-Galante (HG) I or II cups using line-to-line fit and additional screw fixation. Polyethylene linersγ-sterilized in air and 32-mm ceramic heads were used. 8 patients died within 12 years, leaving 50 patients with a complete 12year follow-up. 23 of the cups were also evaluated with radiostereometry (RSA) for migration, liner stability, and wear.Results All metal shells were still in situ after 12 years. 4 hips had been revised due to femoral loosening. In these revisions, the liner had been exchanged due to wear and/or instability, resulting in a cup survival rate of 89%. 28 cups displayed osteolytic lesions, mainly in relation to screws. RSA revealed minimum translations, but in many cases there were pronounced liner rotations suggesting unstable liners within the metal shell. The annual proximal wear was 0.09 mm and the three-dimensional wear was 0.16 mm.Interpretation RSA can predict the long-term performance of cup fixation. Low migration during the initial years after implantation indicates excellent long-term results regarding fixation of the metal shell. The main problem with this design appears to be liner instability and osteolysis, factors that are probably interrelated. Because these phenomena are clinically silent, we recommend regular follow-up of patients with HG cups to avoid sudden loosening and complicated revisions.

Different loss of BMD using uncemented press-fit and whole polyethylene cups fixed with cement: Repeated DXA studies in 96 hips randomized to 3 types of fixation

Background In cemented THA, aseptic loosening of the cup is more common than loosening of the stem, while periprosthetic osteolysis of the socket resulting in difficult reconstruction problems has emerged as the most significant problem with cementless cup fixation.Patients and methods 90 patients (96 hips) scheduled for THA were stratified in three groups according to the method of fixation of the acetabular component: acrylic bone cement with fluoride (Cemex-F), porous-coated press-fit cup with ceramic coating (Trilogy, uncemented) and acrylic cement with gentamicin (Palacos). All patients received the Spectron EF stem. Acetabular bone mineral density was measured with dual-energy X-ray absorptiometry (DXA) 1 week postoperatively, and after 12 and 24 months. The periprosthetic BMD was evaluated in 5 ROIs positioned around the acetabular component.Results In the uncemented sockets, the BMD had decreased proximally and medially to the cup after 2 years. The difference was significant in the proximal region as compared to the control group (Palacos). No difference was noted between the 2 groups with cemented components after 2 years. Stepwise linear regression analysis showed that loss of periprosthetic BMD in the proximal high-pressure region after 2 years increased with higher postoperative BMD and when the uncemented design had been used.Interpretation Contrary to previous studies of cemented stems, the use of fluoride cement did not influence the periprosthetic BMD 2 years after the examination. Increased loss of BMD with use of uncemented press-fit cups in the region in which osteolytic lesions are commonly found suggests that stress shielding may initiate the development of this complication. Longer follow-up will, however, be necessary to substantiate this hypothesis.

Arc-deposited Hydroxyapatite-coated Cups

A second-generation arc-deposited hydroxyapatite-coated acetabular component was developed after detailed analysis of a failed first-generation grit-blasted hydroxyapatite-coated cup. In our prospective multicenter study we aimed to compare clinical results and survivorship of the newly designed cup to the previous cup and to a similarly designed porous-coated cup during the same time period. The effect of bearing surface-alumina-on-alumina to polyethylene-on-metal-was analyzed. Consecutive patients were assigned randomly to one of three groups: arc-deposited hydroxyapatite-coated cup with alumina-on-alumina bearing surface; porous-coated cup with alumina-on-alumina bearing surface; or porous-coated cup with polyethylene-on-metal bearing surface. A fourth comparison group with a grit-blasted hydroxyapatite-coated cup and polyethylene-on-metal bearing surface was culled from a previous study. Acetabular mechanical failure rate is 0.0%, 0.0%, 1.9%, and 11.2% for the arc-deposited hydroxyapatite-coated, porous-coated with alumina bearing surface, porous-coated with polyethylene-on-metal bearing, and grit-blasted hydroxyapatite-coated cup, respectively, at 4- to 7-years' followup. There are no cases of acetabular osteolysis or femoral neck scalloping and no radiolucent lines in any zone with the arc-deposited hydroxyapatite-coated cup. The cups with the alumina-on-alumina bearing surface had less scalloping of the femoral neck than those with a polyethylene-on-metal bearing surface. Early results with this second-generation arc-deposited hydroxyapatite-coated cup are promising. Therapeutic study, Level I (high-quality randomized trial with statistically significant difference or no statistically significant difference but narrow confidence intervals). See the Guidelines for Authors for a complete description of levels of evidence.

A single and versatile acetabular revision system in any case of failed acetabular component

Implant loosening and osteolysis can be associated with massive bone loss. Since the structural quality of bone is difficult to assess accurately with any type of preoperative study, the surgeon needs to be ready to alter the course of the operation based on the circumstances found during surgery and must be prepared with a variety of implants and techniques. We reviewed the results of 88 acetabular revisions performed with the Sph acetabular revision system (Lima-Lto, Italy). This system allows us to choose, during the operation without changing the instrument set, between a hemispherical porous-coated cup, a winged reconstruction ring with an uncemented inner module and a bilobed cup. We implanted 31 Contact, 39 Bicomponente and 18 Bilobo cup implants. Eighty-four of the 86 cases (97.7%) were considered clinically successful at the short-term follow-up (average, 30 months; maximum, 68 months) with stable fixation and reconstruction of periacetabular bone. These encouraging short-term results confirm the importance of an appropriate technique depending on the type of bone loss.

The Effect of Total Hip Arthroplasty Cup Design on Polyethylene Wear Rate

Using 743 total hip arthroplasties that included 6 hemispheric porous-coated cup designs, this study used a multiple linear regression to identify those factors that influenced polyethylene wear rates. Wear rates for each hip were based on serial head penetration measurement made with computer-assisted techniques. Implant factors associated with an increased wear rate included terminal sterilization with a non–cross-linking chemical surface treatment, a 4-mm lateralized liner, a cobalt-chrome femoral head, and a longer shelf life for liners γ-irradiated in air. After accounting for these implant characteristics and patient factors, wear rates among the 6 cup designs were not significantly different ( P = .89). Although polyethylene wear is frequently characterized for specific implant designs, this study demonstrated that there are several common factors that influence polyethylene wear rates.

Ceramic-On-Ceramic Implants in Total Hip Arthroplasty

Alumina ceramic is an excellent material for biologic implantation. Decreased particulate wear debris should increase implant longevity. The purpose of this study is to examine clinical and radiological results of ceramic-on-ceramic hip implants compared to cobalt chrome on polyethylene. Four cementless systems were compared, three alumina-on-alumina bearing systems: System I, porous coated cup; System II, hydroxyapatite-coated cup; Trident system, hydroxyapatite-coated cup with metal sleeve backing on ceramic cup liner; and System III (control), porous-coated cup with polyethylene and cobalt chromium bearing system. Patients were randomized to receive System I, II, or III. Trident patients were not randomized. Examinations are performed at 6 months, 1 year and yearly thereafter including x-rays, clinical exam and Harris Hip Score (HHS). Minimum 24-month followup was performed in 562 ceramic hips and 154 control hips. Age, height, weight, gender and diagnosis were similar in all groups. HHS was rated good/excellent by 95 percent of ceramic hips and 97 percent of control hips. Radiographic results demonstrated radiolucency in Femoral Gruen Zone 1 in 3.8 percent (18/474) of ceramic hips and in 8 percent (10/128) of control hips. Unstable acetabular components were reported in none of ceramic hips and in 3.2 percent (5/154) of control hips. Revision was performed in 7 (1.2 percent) ceramic hips, none due to failure of ceramic materials, and in 9 (5.8 percent) control hips. Alumina ceramic materials show promise, but continued evaluation of long-term clinical results is needed.