Treatment of major defects of bone with bulk allografts and stemmed components during total knee arthroplasty

We reviewed the results an average of fifty months (range, twenty-four to 120 months) after the use of thirty-five allografts in thirty patients during primary or revision total knee replacement. Twenty-nine femoral-head allografts, five distal femoral allografts, and one proximal tibial allograft were used in conjunction with a long-stemmed implant to reconstruct large osseous defects. The patients were evaluated clinically, radiographically, and subjectively (with use of a questionnaire). Twenty-six (87 per cent) of the thirty patients had a good or excellent clinical result, and no revisions were necessary. As none of the patients had collapse of the graft, subsidence of the implant, or revision, we believe that the outcome of treatment with a femoral-head allograft, particularly in association with a component inserted with cement, is excellent. Four non-porous-coated components were placed without cement on structural allografts. Radiographically, three of those components subsided, but none of the three needed revision and two were associated with a good clinical result. Our current practice is to cement components in all arthroplasties involving grafting. Our findings suggest that the use of a stemmed component reduces the stress on the allograft, host bone, and fixation interface. In addition, such a component contributes to the longevity of a total knee replacement associated with a bone graft. Additional studies with long-term follow-up are necessary to confirm this outcome.     

Diagnosis and treatment of osteogenic sarcomas, techniques of reconstructions. Future prospects

PATIENTS AND METHODS: We have performed 34 massive bone-cartilage grafts with a follow-up of 2 to 7 years (1988-1993) including 5 complete joint grafts of the knee. Between 1988 and 1993, 8 massive diaphyso-metaphyseal bone grafts were performed. Joint reconstructions using massive bone-cartilage allografts are increasingly used in routine oncology surgery. Long-term rehabilitation and possibilities of immediate anatomic reconstruction of the articular surface, together with mid-term results suggest that the functional results are promising compared with major reconstruction prostheses. Indications for operations are being increasingly widened to younger subjects who have undergone partial or total joint exeresis for tumour. Sleeved prostheses were used for 12 reconstructions (1988-1993) for sarcoma of the knee. RESULTS The risk of sepsis are comparable for the different groups and are mainly related to the quality of the skin repair during chemotherapy. Fractures of the graft occur when the fixation is insufficient or when rehabilitation exercises were too aggressive. Non-consolidation was exceptional when the junction between the allograft and the receiver bone is not surrounded with autologous spongious autografts. Joint instability and arthrosis depend on the stability of the ligament reconstruction. To this day, no Charcot type joint disease has been demonstrated, periarticular innervation has maintained joint trophism. DISCUSSION: There are still some incompletely resolved problems concerning the revascularization of the graft, its integration into the skeleton, the outcome of the grafted cartilage and that of the ligament formations attached to the graft or used as allografts. These massive grafts must be studied over a longer period of time but the early results are encouraging. Sleeved grafts using bone-bank specimens could be an intermediary solution which appears to be indicated in cases where the tumoural resection was particularly large removing bone, cartilage, ligaments and muscles. With these sleeved prostheses, the muscles can be refixed onto the graft thus reducing the risk of shank fracture and loosening. The use of a tibial graft with the patellar tendon is helpful in reconstructing the extensor apparatus. However, if rehabilitation is not undertaken rapidly and followed regularly for several months, the graft favours the development of muscular adherances which can be a major limitation to joint mobility.     

The viability of cryopreserved onlay cranial bone allografts: a comparative experimental study versus fresh autografts

It is well known that calvarial bone autografts are the bone grafts that are the least reabsorbent and have the best long-term evolution in craniofacial surgery. However, they do have certain limitations: (1) reabsorption results in repeated surgery and the need for new donor areas, (2) a limited amount of autogenous cranial bone is available (due to avoiding areas close to cranial sutures and venous sinuses, and because the temporal bone is very fragile and the cranium has not fully developed in children), and (3) graft extraction increases surgical time and morbidity. Because of this, we present an alternative to calvarial bone autografts: cryopreserved allografts. This paper is an experimental prospective study carried out on sheep with the following goals: (1) to assess the behavior of calvarial onlay bone grafts cryopreserved at -80 degrees C, using fresh autografts implanted under the same conditions as controls; (2) to compare reabsorption percentages statistically over time; and (3) to study qualitatively any histological variations. The results obtained are (1) more reabsorption of allografts when compared to autografts (at 90 days, 21.97% versus 20.21% of grafted volume), although this difference is not statistically significant; (2) a reduction in height in all onlay grafts as a consequence of the loss of the dipl?e; (3) the absence of any type of inflammation caused by a reaction to cryopreserved allografts; and (4) bone substitution performed using frozen allografts is histologically similar to that using fresh autografts.     

Hybrid fixation modular tibial prosthesis. Early clinical and radiographic results and retrieval analysis

A prosthetic tibial component has been designed with features for fixation to bone using a combination of acrylic cement and ingrowth interfaces. This hybrid concept affords the component the immediate stability of cement fixation and the potential long-term stability of biologic fixation. The ingrowth interfaces (coupled with the central stem) are intended to shield the cement interface beneath the tibial tray from the tensile liftoff forces that result from eccentric loading, while avoiding the fretting and osteolysis associated with screw fixation. A disassembly capability allows the tray to be removed from the stemmed anchorage assembly, facilitating component extraction and limiting bone loss. A clinical and radiographic review of 50 consecutive primary total knee arthroplasties with a mean follow-up period of 35 months revealed stable interfaces with no progressive radiolucencies and minimal remodeling changes. The mean Knee Society knee score was 92.2. At final follow-up evaluation, 88.6% of patients noted no or mild (occasional) pain. Retrieval of three prosthetic knees with chronic sepsis showed extensive ingrowth into the porous interfaces and an osteointegrated bony sleave around the smooth central stem.     

Articular cartilage transplantation

This report describes the biopsy findings in four of 30 patients treated with cadaver osteochondral shell allografts for osteoarthritis in the knee. This study demonstrates that graft cartilage cells can survive in excess of 25 months, and that host bone can completely replace graft bone by creeping substitution. An inflammatory reaction in synovium and bone marrow was found in only one of four cases. Graft failure was related to prolonged down time of donor cartilage in one case and mechanical factors related to osteoarthritis in the apposing femoral surface in other cases. The clinical success of these grafts is attributed to the prolonged viability of cartilage cells, the capacity of host bone to join graft cartilage without histologic reaction, and the host's immunologic tolerance, which obviates the need for immunosuppressive therapy.     

Histologic analysis of clinically retrieved titanium microimplants placed in conjunction with maxillary sinus floor augmentation

In this study, a new approach involving placement and subsequent retrieval of titanium microimplants was employed for the histologic investigation of the implant-tissue interface in conjunction with maxillary sinus floor augmentation. Nine patients scheduled for sinus floor augmentation and simultaneous placement of Br?nemark implants were included in the study. After a sinus graft procedure and placement of implants, an additional microimplant was placed into the graft through the lateral wall of the sinus. At abutment connection, the microimplants were retrieved using a 3- or 5-mm-wide trephine drill. Six specimens were retrieved after 6 to 14 months from sites augmented with particulate radiated mineralized cancellous allograft. Another six implants were retrieved after 6 to 12 months from maxillary sinuses augmented with particulate autogenous bone grafts. The histologic analysis showed distinct differences between the two types of grafts. The sites with autogenous bones grafts displayed a normal morphology of bone and bone marrow, including formation of bone on the surfaces of the grafted particles and remodeling of newly formed as well as grafted bone. The bone was more mature after 11 to 14 months than at 6 months. The allografted sites had a mixed morphologic appearance of newly formed bone and nonviable allograft particles (about 75% of the total bone area) in loose connective tissue. Significantly more bone was found at the autografted than at the allografted implants. The use of autogenous bone for augmentation of the maxillary sinus floor resulted in a greater amount of viable bone surrounding the implant; however, simultaneous placement of implants apparently resulted in a low proportion of bone-implant contact after 6 to 14 months irrespective of graft type.     

Structural allograft in two-stage revisions for failed septic hip arthroplasty

We report 11 patients having revision of total hip arthroplasty using massive structural allografts for failure due to sepsis and associated bone loss. All patients had a two-stage reconstruction and the mean follow-up was 47.8 months (24 to 72). Positive cultures were obtained at the first stage in nine of the 11 patients, with Staphylococcus epidermidis being the most common organism. The other two patients had draining sinuses with negative cultures. There was no recurrence of infection in any patient. The mean increase in the modified Harris hip score was 45 and all the grafts appeared to have united to host bone. Two patients required additional procedures, but only one was related to the allograft. Complications included an incomplete sciatic nerve palsy and one case of graft resorption. Our results support the use of massive allografts in failed septic hip arthroplasty in which there is associated bone loss.     

Impaction of cancellous bone grafts impairs osteoconduction in titanium chambers

The method of using morselized compacted cancellous allografts for hip arthroplasty revision shows results that seem to differ dramatically from other kinds of allografting. In structural cancellous allografts, bone ingrowth usually is limited to 2 to 3 mm, whereas morselized compacted grafts seem to be remodeled totally in several cases, as judged by radiography. In the current study, impacted cancellous allografts were compared with unimpacted allografts. Seventeen rats had a bone conduction chamber implanted in the tibias bilaterally. On one side the chambers contained an impacted graft (bone volume fraction 65%) and on the contralateral side an unimpacted graft (bone volume fraction 35%). Impaction of the grafts was done preoperatively with a pressure of either 25 or 2500 MPa. Ingrowing bone could enter the cylindrical interior of the chamber only at one end. After 6 weeks the mean distance the ingrown bone had reached into the graft was measured on histologic slides. With both impaction pressures, the bone ingrowth distance was decreased to 30% of the unimpacted controls. It appears that impaction alone does not have a favorable effect on the osteoconductive properties of a bone graft. On the contrary, impaction seems to disfavor osteoconduction. However, in the clinical situation this is not necessarily a disadvantage.     

Experience with allografts in the surgery of peripheral nerves (experimental study)

Peroneal nerve allografts four to seven cm in length were transplanted in 36 tissue typed beagle dogs, using a standard microsurgical technique. The influence of tissue typing on nerve regeneration through these grafts was studied with the help of electromyography and histology seven to nine months after nerve implantation. Better regeneration was found through the grafts with compatible than with noncompatible typing. The favourable effect of tissue compatibility became more evident when the length of the graft was longer than four cm. Tissue rejection reaction was much more marked and evident with longer grafts in noncompatible than in compatible groups. Radiation, with tissue typing, did not seem to confer any additional beneficial effect. Compatible tissue typed nerve allografts probably behave more like autografts.     

Revision of failed lumbar fusions. A comparison of anterior autograft and allograft

STUDY DESIGN: The radiographic and clinical results of two different anterior structural grafts were compared in 38 patients who had combined anterior-posterior revision surgery for failed lumbar fusion. OBJECTIVES: Failed lumbar fusion surgery, such as pseudarthrosis or flatback deformity, may result in disabling pain. The optimum revision technique has yet to be defined. The authors of the current study sought to determine which of two different types of anterior graft yields the best results. SUMMARY OF BACKGROUND DATA: Posterior procedures for revision of a failed lumbar fusion have not yielded reliably successful results. A combined anterior-posterior approach may be effective in restoring sagittal balance and enhancing fusion rates. Recent studies have shown femoral ring allografts to be effective in lumbar fusion revision, but no studies have compared these with other types of structural grafts. METHODS: Thirty-eight patients with pseudarthrosis were treated with combined anterior-posterior lumbar spine fusion using either femoral ring allografts (26 patients) or tricortical iliac autografts (12 patients). Radiographic follow-up examination and retrospective patient self-assessment questionnaires were used to evaluate outcomes. Results were assessed by independent reviewers after a mean follow-up period of 35 months. RESULTS: Radiographic follow-up examination revealed acceptably low pseudarthrosis rates for structural autografts (0%) and allografts (6%). The questionnaires revealed significant improvement in pain for both groups. Allograft patients showed greater improvement in function, less pain medication usage, and higher overall success rates (83%) than autograft patients (64%). CONCLUSIONS: Femoral ring allografts are as effective, clinically and radiographically, as tricortical iliac autografts when used as an anterior structural element in revision lumbar spine fusion in patients who have undergone multiple surgical procedures for pseudarthrosis or flatback deformity. The slightly greater improvement for the allograft group needs to be confirmed in a larger study.     

A paradigm of experimentally induced mild hyperthyroidism: effects on nitrogen balance, body composition, and energy expenditure in healthy young men

OBJECTIVE: To conceptualize, with fine needle aspiration cytology (FNAC), the early cellular events occurring in and around fresh autogenous and allogenic bone grafts during the first 40 postimplantation days. STUDY DESIGN: Forty-eight cases of bone grafts were studied by FNAC at serial intervals of 10, 20, 30 and 40 postimplantation days. Twenty patients were recipients of autogenous grafts, 16 received 0.6N HCI partially decalcified allogenic bone implants, and 4 received combined autogenous and allogenic bone grafts (included in the allograft group). There were eight control cases of closed fracture shaft femur, which were managed conservatively. RESULTS: The initial cellular responses in autogenous grafts, allografts and controls appear to be a part of the nonspecific reparative process followed by a more specific phase, with a steady increase in relative lymphocyte count from the 20th day onwards. Osteogenesis, as judged by osteoblasts and osteoclasts, was also comparable. CONCLUSION: Partially decalcified allografts appear to be a good substitute for autogenous bone grafts in clinical practice when adequate autogenous material is not available. FNAC is a good technique for studying bone graft responses without interfering with graft uptake. It is helpful in the early detection of subclinical infection or any other pathology at the graft site.     

Lunate and perilunate dislocation

BACKGROUND: Patellar problem is an important cause of nonseptic failure of the current condylar design of total knee arthroplasties. Patellar dislocation after total knee arthroplasty is infrequent but can cause disabling symptoms. METHODS: From March, '84 to July, '92, 1652 total knee arthroplasties were performed at this Hospital. Of these 1100 knees in 978 patients were available to be followed up regularly at the Outpatient Department. Eleven cases of patellar dislocation after total knee arthroplasty were encountered during follow-up. Among these patients, nine patients had received operation at this Hospital; the other two patients had been referred here by the other hospitals. All 11 patients had been treated with surgical methods: proximal realignment of the quadriceps alone in 6 knees, lateral retinacular release combined with revision of the malaligned components in 2 knees, combined proximal and distal realignment in 2 knees and patellar tendon transfer in 1 knee. RESULTS: After an average follow-up of 21.8 months, from April, '84 to April, '93, there was one redislocation, unfortunately caused by trauma. Using the average knee rating scale of the Hospital for Special Surgery, New York, USA, the results of 90.5 were satisfactory and encouraging. CONCLUSIONS: Patellar dislocation after total knee arthroplasty can cause disabling symptoms, including pain, weakness, limited range of motion, extension lag and difficulty when climbing up or down stairs. The cause of patellar dislocation after total knee arthroplasty was error in surgical technique in this series. Revision of the component should be performed in those with malaligned component. Proximal realignment is recommended in those with quadriceps imbalance. Distal realignment is recommended only when proximal realignment alone has failed to restore proper patellar tracking, this should be carried out with great caution due to the potential for serious complications.     

Value of scaphal graft in secondary rhinoplasties

The scaphal cartilaginous area is a most suitable anatomic site for cartilaginous graft harvesting. These grafts allow reconstruction of a flat dorsum, or a rounded dome, or alar cartilages or can be used for an extended tip graft. In some cases, both scaphes may be harvested. Raising of the grafts does not leave any sequelae when performed correctly. We have an experience of 20 cases. The main advantage of this graft is its flatness, which makes it ideal for the nasal dorsum. It has to be tailored, moderately crushed and included in a collagen "surgicel" in order to break the shape memory, slightly curved at its borders. We have used scaphal autografts in 15 cases of secondary rhinoplasties, 2 cases of cleft lip repair and in 3 cases of tertiary rhinoplasties. They solved most problems of missing cartilage, when minor defects had to be treated. These grafts will not solve major tissue defects which must be repaired by bone autografts, mostly iliac bone harvesting in our experience. The results of scaphal autografts are stable after 5 years. Resorption is moderate when the graft is correctly inserted, in an extramucosal pocket. The aesthetic result is maintained with a mean follow up of 2 years for 15 cases. The scaphal area of the ear therefore appears to be a favorable donor site for secondary, nose repair; it is easy to harvest, with inconspicuous morbidity and allows the raising of a good, flat and sculpturable material for cartilaginous nose replacement. Achieves the objectives of ore informed patients asking for artistic perfection.     

Low friction total knee arthroplasty with the alumina ceramic condylar prosthesis

This paper evaluates the failure and wear properties of the alumina ceramic posterior cruciate condylar total knee prosthesis, and reports the preliminary clinical results of this prosthesis. Thirteen sets of the alumina ceramic prostheses were used for destruction and wear tests. The average ultimate load in the static destruction tests showed 2.63 x 10(4) Newtons in the femoral component, and 1.28 x 10(4) Newtons in the tibial component. The average ultimate energy in the impact destruction tests showed 22.1 Joules in the femoral components, and 20.3 Joules in the tibial components. The wear test demonstrated that the average depth of wear was 0.04 mm in the alumina ceramic prostheses, and 0.20 mm in the Vitallium prostheses. Observation of the UHMWPE wear surface with a scanning electron microscope indicated many deep scratches and a scooped concave lesion in the Vitallium prostheses; there were few deep scratches in the alumina ceramic prostheses. Thirty patients underwent 32 total knee arthroplasties using the alumina ceramic posterior cruciate condylar prosthesis between 1988 and 1990. The results were evaluated as excellent for 59%, good for 28%, fair for 10%, and poor for 3%. Critical roentgenographic review demonstrated no cases of loosening or sinking after arthroplasties using the alumina ceramic prosthesis. Radiolucent lines were observed only in 4 knees (12%) cases. All were observed around the tibial components, but were less than 1 mm in thickness. The frequency of the radiolucent lines is less than that observed in the Vitallium prosthesis at the same followup period. The alumina ceramic posterior cruciate condylar prosthesis may have sufficient durability and excellent wear properties for low friction total knee arthroplasty.     

Ionizing radiation and TNF-alpha and stimulated expression of alpha1-antichymotrypsin gene in human squamous carcinoma cells

We studied the management of postoperative drainage after total knee replacement (TKR). 90 primary total knee joint arthroplasties were prospectively randomized into 3 groups: a) no drain, b) an autotransfusion system, c) a standard disposable closed suction drainage system. We monitored hemoglobin and hematocrit values, drainage volume and transfusions (homologous and autologous), range of knee motion, knee swelling and hospital stay. Parameters were recorded preoperatively, days 0-8 and 4 months postoperatively. No significant differences were seen between the groups in any of the parameters measured. The results show no benefit from using postoperative drainage systems in knee arthroplasties. Savings of SEK 400 (USD 55) per patient would have resulted if drains had not been used at all.     

Stability of proximal femoral grafts in canine hip arthroplasty

In a canine model, the fixation stability of a prosthesis and proximal bone graft composite were measured relative to the distal femur. One group had the prosthesis graft composite cemented into the distal femur. The second group had the prosthesis graft composite press fit into the distal femur for biologic ingrowth. Displacements of the proximal femoral grafts relative to the host bone in each group were measured after ex vivo (acute with graft) implantation and 4 months after implantation. A third group with no osteotomy (acute intact) simulated perfect graft to host bone union. Relative displacements representing 6 degrees freedom (translation and rotation) were calculated from the displacement values measured by 9 eddy current transducers. Measurements of displacement were used to test the hypothesis that distal press fit fixation equals distal cement fixation at 4 months after implantation. In all cases the measured translations and rotations of the graft to implant construct were small and of a magnitude that should encourage bone ingrowth (< 0.05 mm and < 0.1 degree, respectively). The stability of the press fit group at 4 months was not significantly different from the cemented group in axial and transverse displacement during axial and transverse loading, respectively. There was no difference in stabilities at 4 months between distal press fit and cemented fixation in hip replacements requiring a proximal femoral graft.     

A comparison of patellar tendon autograft and allograft used for anterior cruciate ligament reconstruction in the goat model

Similar-sized patellar tendon autografts and fresh-frozen allografts were used to reconstruct the anterior cruciate ligament of one knee in 40 female goats. Evaluations of the reconstructions and contralateral controls at the 6-week and 6-month postoperative periods included anterior-posterior translation, mechanical properties determined during tensile failure tests, measurement of cross-sectional area, histology, collagen fibril size and area distribution, and associated articular cartilage degenerative changes. Six months after anterior cruciate ligament reconstruction, the autografts demonstrated a smaller increase in anterior-posterior displacement, values of maximum force to failure two times greater, a significant increase in cross-sectional area, a more rapid loss of large-diameter collagen fibrils, and an increased density and number of small-diameter collagen fibrils compared to the allografts. Clinical significance. More surgeons are allowing their patients to return to running and sports 6 months after anterior cruciate ligament reconstruction. While the structural and material properties of autografts and allografts at time zero are similar, in the goat model during the first 6 months they differ. The allografts demonstrate a greater decrease in their implantation structural properties, a slower rate of biologic incorporation, and the prolonged presence of an inflammatory response. At 6 months the autograft demonstrates a more robust biologic response, improved stability, and increased strength to failure values.     

Allogeneic vascularized transplantation of human femoral diaphyses and total knee joints--first clinical experiences

This article has presented the preliminary results of three patients who received vascularized allogeneic femoral diaphyses and three patients having undergone vascularized transplantation of fresh and perfused total human knee joints. The large osseous defects in the femora followed osteomyelitis and chondrosarcoma. The three knee joints were lost due to various trauma mechanisms. All grafts were harvested within 25 hours from multiorgan donors perfused with 4 L of UW solution. All osteosyntheses were performed employing intramedullary nails. Vascular pedicles of the grafts were anastomosed end-to-side to the superficial femoral artery and vein in the adductorial canal of the recipient thigh. Immunosuppression was based mainly on two drugs: CyA and AZA. Perfusion of the grafts was demonstrated by DSA, and bone metabolism in the graft by SPECT scintigraphy. Six months after the operation all osteotomies demonstrated callus formation and osseous consolidation in conventional radiographs. Biopsies of the grafted bone revealed intact osteocytes, and arthroscopy of the transplanted knee joints demonstrated intact synovial, chondral, and ligamentous structures. From the surgical aspect, the vascularized transplantation of the femoral diaphyses and total knee joints is technically feasible. The main problems are immunologic. All transplantations were performed with respect to ABO compatibility, but with a large HLA mismatch. Therefore, acute and chronic rejection crises were observed. In total synovial joints, lifelong immunosuppression of graft recipients seems to be currently unavoidable.     

Hospital controls versus community controls: differences in inferences regarding risk factors for hip fracture

In cranioplasty complexity is proportional to the size of the detect, particularly if greater than 50 cm2. If the patient's own bone flap is not available, allogenic frozen bone graft can be used instead. Between June 1990 and June 1995 twenty cranioplasties with allogenic frozen bone grafts were performed. Age of patients ranged between 23 and 63 years (average 38.4 years). Male/female ratio was 2:1.7. Size of craniectomy ranged between 65 and 150 cm2 (average 83.3 cm2). Follow-up ranged between 10 and 58 months (average 41 months). Donors were tested to rule out transmissible diseases, infections, sepsis and/or cancer. Bone grafts were removed under aseptic conditions, microbiological cultures were taken, wrapped in a gauze soaked with Gentamicin sulphate and Bacitracin, sealed in three sterilised vinyl plastic bags, and stored in a deep freezer for a minimum of 30 days (range 36-93 days, average 67 days), at a temperature of -80 degrees C. Grafts were placed in the defect after a step was carved on its borders to facilitate the contact between host and graft. Vancomycin 1 g. IV/12 hours and Ceftriaxone 1 g. IV/12 hours were administered for five days. Grafts were covered by means of scalp flaps. Only one required a musculocutaneous free flap. None was exposed, extruded or had to be removed. Plain skull X-ray studies showed progressive remodelling of the grafts. Partial resorption was observed in two (2/20, 10%) and loss of thickness in another 3/20 (15%), but with no changes in the contour. Biopsies were taken in 3/20 (15%) cases at a second surgical procedure. Areas of osteoclastic resorptive activity mixed with others of osteoblastic bone apposition, showed replacement with new bone. We conclude that cranial vault frozen allografts are a good alternative to autologous bone when the latter is absent or not present in sufficient amount.     

The porous-coated anatomic total hip prosthesis: failure of the metal-backed acetabular component

One hundred and ninety-nine total hip arthroplasties were performed, between 1983 and 1987, in 173 patients by three surgeons using the initial design of the porous-coated anatomic prosthesis. The acetabular component was a preassembled, metal-backed polyethylene device, with beads sintered to the metal backing to allow bone ingrowth and two pegs for initial fixation. Twenty-three acetabular components (12 percent) failed because of either migration or severe osteolysis. The radiographic appearance of osteolysis was positively associated with the duration that the implant had been in situ (p < 0.001). The prevalence of osteolysis was also significantly greater in acetabular components with an outer diameter of fifty-five millimeters or less (a polyethylene thickness of 8.5 millimeters or less) (p = 0.03). Thirteen hips were revised at a mean of 69.5 months (range, thirty-three to ninety-one months) after the index operation. Examination of the retrieved acetabular components revealed extensive polyethylene damage on the articular and back surfaces of the liners. Cracks in the polyethylene rim of the liner and deformation of the anti-rotation notch in the polyethylene rim were common findings. The density of the polyethylene was greater than expected, and more particles than anticipated had not fused with the surrounding polyethylene. The results of this study suggest that factors related to both the design and the material contributed to the failure of these porous-coated anatomic acetabular components.