Porous-coated Acetabular Cups Research Articles

Patient-reported and radiographic outcomes of a porous-coated acetabular cup in robotic assisted total hip arthroplasty at 2-year follow up

Patient-reported and radiographic outcomes of a porous-coated acetabular cup in robotic assisted total hip arthroplasty at 2-year follow up

The early- to medium-term results of a hemispherical, porous coated acetabular shell with multiple different bearing combinations are excellent with the exception of metal-on-metal.

This study prospectively reports survivorship and radiographic and clinical outcomes following primary elective total hip arthroplasty (THA) using a novel single hemispherical, porous-coated acetabular cup with five different bearing combinations and a minimum of fiveyear follow-up. Continuing post-market release monitoring of this cup, we prospectively enrolled 108 patients (121 THA) between 2009 and 2015. We followed this cohort by examining survivorship, in addition to clinical and radiological outcomes for metal-on-metal (MoM) compared with non-MoM bearing combinations (ceramic-on-ceramic, oxinium-on-polyethylene, ceramic-on-metal, and metal-on-polyethylene). All 108 (121 hips) patients were followed up. Average age at time of surgery was 45.1years (range 19 to 71years) of which 42.1% were males. A total of seven (5.8%) cups were revised, all of which were MoM. No osteolysis was observed in any of the patients at the latest visit with a mean follow-up of 9.1 ± 1.7years (range 4.4-10.7years). With MoM excluded, survivorship of the cup at fiveyears is 97.8%. Survivorship for MoM implants was 90.0%. Validated hip scores showed significant improvements for all bearing types and no significant difference between groups at latest follow-up (p = 0.614). There was no cup migration with any bearing surface. This cup showed excellent survivorship at fiveyear follow-up, except for patients receiving a MoM articulation. While there were concerns over the early survivorship of this cup, our cohort and joint registry data confirm excellent outcomes.

Functional Outcomes of Cementless Total Hip Arthroplasty in Avascular Necrosis of the Hip: A Prospective Study.

IntroductionAvascular necrosis occurs due to impaired blood supply to the bone. It can be caused by fractures, dislocations, chronic steroid use, chronic alcohol use, coagulopathy, congenital source, and many other factors. It mostly affects the femoral head (hip joint). Its management can be conservative or invasive. Total hip arthroplasty is the treatment of choice for third and fourth stage avascular necrosis that can be cemented or uncemented. The purpose of this study is to access the functional outcomes of cementless total hip arthroplasty in patients with avascular necrosis of the hip.Materials and methodsThis prospective study was conducted at a major metropolitan hospital in Karachi, Pakistan over a period of six months. A total of 30 patients of age <60 years, either gender, and a confirmed diagnosis of avascular necrosis of hip with no other associated hip pathologies were included in this study. Demographic features, comorbidities, level of activity, range of movement before the development of avascular necrosis, Charnley's class, and laterality were noted. Cementless press-fit extensively porous-coated acetabular cup with or without cancellous screws and cementless press-fit extensively hydroxyapatite coated femoral stem were used through modified Gibson's posterior approach. The patients were checked for early and late complications, the position of acetabular and femoral components by radiography, and overall performance by Harris Hip Score (HHS) and modified HHS over a period of 12 months. All statistical analyses were performed using Statistical Package for Social Sciences (SPSS) version 19.0 (IBM Corp, Armonk, NY).ResultsThe mean age was 43.9±6.7 years with 21 (70%) patients ranging from 40 to 60 years of age. There were 22 (73%) male and 8 (27%) female patients. Nine (30%) patients had diabetes mellitus, eight (27%) had hypertension, two (7%) had other comorbidities, and eleven (37%) had no comorbidities. A total of 11 (37%) patients were highly active, 18 (60%) were moderately active, and 1 (3%) was non-active before developing avascular necrosis. There were 4 (13%) patients in Charnley's class I, 15 (50%) in Charnley's class II, and 11 (37%) in Charnley's class III. Fifteen (50%) patients were operated on the left side, seven (23%) on the right side, and eight (27%) bilaterally. No significant early or late complications were noted. Acetabular component was found to be anteverted in 22 (73%), retroverted in zero (0%), neutral in 8 (27%), <35o inclined in 0 (0%), 35o-50o inclined in 23 (77%), and >50o inclined in 7 (23%) patients, while femoral component was found neutral in 28 (93%), valgus in 2 (7%), and varus in zero (0%) patients on radiography at follow-up. On functional assessment, the HHS was 100% in 27 (90%) patients, 96% in 2 (7%) patients, and 83% in 1 (3%) patient with an average of 99.2%, while 29 (97%) patients had excellent and only 1 (3%) patient had a good outcome on modified HHS.ConclusionsCementless total hip arthroplasty, performed in patients <60 years of age and avascular necrosis of the hip with no other associated hip pathologies, has excellent functional outcomes with no pain, limping, physical deformity, difficulty in walking, difficulty in climbing stairs, difficulty using public transport, difficulty in sitting, or difficulty in wearing shoes and socks. They usually attain normal limb length and range of movement.

No superior performance of hydroxyapatite-coated acetabular cups over porous-coated cups

Background and purpose Hydroxyapatite (HA) coating is believed to improve bone-implant ingrowth and long-term survival of prostheses. Recent studies, however, have challenged this view. Furthermore, HA particles may produce third-body wear and initiate aseptic loosening of implants. We report the performance of HA- and porous-coated acetabular cups in a prospective randomized trial.Methods This was an 8-year follow-up study of our previously published prospective randomized study to compare clinical outcomes, survival, periprosthetic bone mineral density, migration, and wear rates of HA- and porous-coated acetabular cups. Dual X-ray absorptiometry (DXA) and Ein Bild Roentgen Analyse (EBRA) measurements were used. 100 patients who underwent unilateral cementless total hip arthroplasty were randomized to either porous-coated cups or HA-coated cups. Patients were examined preoperatively and at 3, 6, and 9 months, and also 1, 3, and 8 years after surgery. 81 patients were available for 8-year follow-up, 40 with porous-coated cups and 41 with HA-coated cups.Results Age, sex, bone mineral density, and clinical results (Harris hip score) were similar in the 2 groups. The survival, wear, and migration patterns of the cups were also similar in both groups. The results of periprosthetic bone mineral density scans in region of interest 2 was in favor of the porous-coated cups, but there were no differences between the 2 groups in all the remaining regions of interest.Interpretation HA coating had no statistically significant effect on clinical results, survival, wear, or migration at the 8-year follow-up.

Modular hybrid total hip arthroplasty. Experimental study in dogs

BackgroundThis prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs.MethodsTen skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation.ResultsExcellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis.ConclusionsThe canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb.

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.

Early Catastrophic Failure of a Porous-Coated Acetabular Cup due to Bead Shedding. A Case Report

We present a patient in whom an uncemented porous-coated acetabular cup underwent early catastrophic failure due to debonding and was successfully managed with a revision total hip arthroplasty. Early bead shedding of an acetabular cup leading to a sudden component failure requiring revision surgery is a rare event.

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.

Cementless Alumina-on-Alumina Total Hip Arthroplasty in Patients Younger Than 50 Years: A 5-year Minimum Follow-Up Study

Sixty-seven patients (78 hips) who were younger than 50 years underwent cementless total hip arthroplasty using a porous-coated acetabular cup, an alumina liner, a 28-mm alumina head, and a proximally porous-coated femoral stem. One patient (1 hip) died and 2 patients (3 hips) were lost to follow-up. The remaining 64 patients (74 hips) were followed for 5 to 6 years. Their mean age at the index operation was 37 years. The mean Harris hip score was 94 points at the time of final follow-up. Four patients (4 hips) had mild thigh pain. All acetabular and femoral components were bone-ingrown, and neither pelvic nor femoral osteolysis was identified. No fracture of the ceramic liner or head was identified. Wear of the ceramic components was undetectable in 27 hips in which measurement was possible.

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.

Porous-Ingrowth Revision Acetabular Implants Secured with Peripheral Screws

During revision total hip arthroplasty, the acetabular component is often secured with screws to ensure initial press-fit stability. The purpose of the present study was to assess a series of acetabular revisions involving the use of a porous-coated acetabular component that was stabilized with peripheral screws and to evaluate the results in relation to the acetabular bone deficiencies that were present at the time of the revision procedure. From 1987 to 1991, 203 consecutive acetabular revisions were performed. In 142 hips, a severe acetabular bone deficiency that did not require an allograft was reconstructed with a porous-coated acetabular cup that was secured with a minimum of two peripheral screws. After an average duration of follow-up of 13.2 years, 134 hips were reviewed clinically and radiographically. The procedure was considered to be a clinical failure if the component was revised or if the postoperative clinical scores were poorer than the preoperative scores. At the time of the most recent follow-up, 127 (95%) of the 134 hips were stable and clinically successful. The other seven hips (5%) were considered to have failed. Five of these seven hips failed because of an infection, and two failed because of aseptic loosening. Five (19%) of the twenty-seven hips with a Paprosky type-3A defect (a defect in which 30% to 50% of the host acetabulum is missing) failed. Revision total hip arthroplasty with use of a porous-coated acetabular component that is fixed with peripheral screws can provide long-term durability in hips with severe acetabular defects that do not require the use of an allograft (Paprosky type-1 and type-2 defects). We recommend that when an acetabular implant with peripheral screws is used for the treatment of a more severe (type-3) defect, the cup should be augmented with structural allograft to improve initial stability, or other implants should be utilized.

POROUS-INGROWTH REVISION ACETABULAR IMPLANTS SECURED WITH PERIPHERAL SCREWS

Background: During revision total hip arthroplasty, the acetabular component is often secured with screws to ensure initial press-fit stability. The purpose of the present study was to assess a series of acetabular revisions involving the use of a porous-coated acetabular component that was stabilized with peripheral screws and to evaluate the results in relation to the acetabular bone deficiencies that were present at the time of the revision procedure. Methods: From 1987 to 1991, 203 consecutive acetabular revisions were performed. In 142 hips, a severe acetabular bone deficiency that did not require an allograft was reconstructed with a porous-coated acetabular cup that was secured with a minimum of two peripheral screws. After an average duration of follow-up of 13.2 years, 134 hips were reviewed clinically and radiographically. The procedure was considered to be a clinical failure if the component was revised or if the postoperative clinical scores were poorer than the preoperative scores. Results: At the time of the most recent follow-up, 127 (95%) of the 134 hips were stable and clinically successful. The other seven hips (5%) were considered to have failed. Five of these seven hips failed because of an infection, and two failed because of aseptic loosening. Five (19%) of the twenty-seven hips with a Paprosky type-3A defect (a defect in which 30% to 50% of the host acetabulum is missing) failed. Conclusions: Revision total hip arthroplasty with use of a porous-coated acetabular component that is fixed with peripheral screws can provide long-term durability in hips with severe acetabular defects that do not require the use of an allograft (Paprosky type-1 and type-2 defects). We recommend that when an acetabular implant with peripheral screws is used for the treatment of a more severe (type-3) defect, the cup should be augmented with structural allograft to improve initial stability, or other implants should be utilized. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Long-term results of uncemented acetabular cups with an ACS polyethylene liner. A 14–16-year follow-up study

We assessed the clinical and radiographic results of 40 porous-coated acetabular cups with an Acetabular Cup System polyethylene liner over a minimum 14-year follow-up. Femoral head penetration was estimated using a software package. Fifteen cups were revised, 11 due to polyethylene liner rupture. All cups but two were radiographically stable, and 11 hips showed acetabular osteolysis. The overall femoral head penetration rate in hips without liner fracture with reference to the early penetration point was 0.1188+/-0.070 mm per year. Polyethylene liner fractures were associated with higher early femoral head penetration (P<0.0001) and a vertical cup position (P=0.0016). The 14-year survival without cup revision for any reason was 63.9%, 71.8% with no ACS polyethylene liner fracture and 65.3% with no acetabular osteolysis. Most cups showed a good clinical outcome in general, but major Acetabular Cup System liner failure and osteolysis were frequent. Patients with the ACS cups still in place should be monitored closely.

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 cups with and without hydroxylapatite-tricalcium phosphate coating: 23 matched pairs evaluated with radiostereometry

Migration, wear, and presence of radiolucencies were studied in 23 matched pairs of patients operated with porous-coated acetabular cups with additional screw fixation. All implants had the same type of titanium fiber mesh. In each pair, one of the cups was plasma-sprayed with a coating consisting of 70% hydroxylapatite (HA) and 30% tricalcium phosphate (TCP). Radiostereometric analysis up to 2 years after the operation revealed smaller rotations around the horizontal axis in cups with HA/TCP coating. The migration of the cup center was not significantly influenced. Evaluation of femoral head penetration in 12 of the matched pairs did not reveal any significant difference. Immediately after operation, implants with HA/TCP coating had more central radiolucencies, which, despite minimal migration, disappeared during the follow-up. The clinical results did not differ between the 2 groups. The findings of less tilting and diminishing radiolucencies in the cups with HA/TCP coating suggest a more complete ingrowth of bone and a better sealing of the interface.

Bone Ingrowth Rate on Retrieved Human Porous-Coated Acetabular Cup

Bone Ingrowth Rate on Retrieved Human Porous-Coated Acetabular Cup