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At least 271 records · Page 15Linked to original sources
PubMed1999

The role of acetabular component screw holes and/or screws in the development of pelvic osteolysis.

Anecdotal reporting of osteolysis around cementless modular acetabular components with holes through the metal shell and/or iliac fixation screws has raised concern that such designs may generate excessive particulate debris and/or permit direct access of particulate debris to iliac bone. To address this issue, incidence data are reported on 513 total hip replacements from six different single-surgeon series of total hip arthroplasties performed with six different porous ingrowth acetabular components. With follow-up ranging from 40 to 108 months, a total of 45 pelvic osteolytic lesions were observed (8.8 per cent). Pelvic osteolysis was seen nearly as frequently in the ischium and pubis (21 lesions) as it was in the ilium (24 lesions). It was not possible to explain ischial and pubic osteolysis by holes and/or screws through the acetabular component shell. There was no direct correlation between the presence of screw holes or screws and the incidence of pelvic osteolysis. The incidence of pelvic osteolysis around modular components with holes through the shell was 4.5 per cent (14 of 313 hips). The incidence of pelvic osteolysis with solid-shell components was 15.5 per cent (31 of 200). The incidence of pelvic osteolysis around acetabular reconstructions with screws was 2.3 per cent (3 of 133). The incidence of pelvic osteolysis in reconstructions without screws was 11.1 per cent (32 of 380). The incidence of pelvic osteolysis in one-piece acetabular components (polyethylene pre-fixed in the metal shell) was 12.7 per cent (21 of 165) and the incidence of pelvic osteolysis with the modular components was 6.9 per cent (24 of 348). In each comparison, the incidence of pelvic osteolysis was actually lower in the group assumed to be at increased risk. Based on this review there does not appear to be a direct relationship between holes and/or screws through an acetabular component and the development of pelvic osteolysis. The incidence of pelvic osteolysis was associated with larger head diameters and longer follow-up. While screw holes may provide an access channel in specific cases, the present data indicate that the simple elimination of holes through the acetabular shell will not eliminate pelvic osteolysis. Regardless of other acetabular component design features, joint fluid and polyethylene wear particles from the femoral-acetabular articulation can gain access to bone behind an acetabular component via the peripheral implant-bone interface through regions without sufficient contact or tissue ingrowth. The development of pelvic osteolysis is multifactorial and includes the total volumetric wear of polyethylene as well as specific features of the acetabular component design and reconstruction technique.

Adult↗
PubMed2000

A case report of insufficiency fracture of the Fossa acetabuli in a patient with rheumatoid arthritis.

Aside from vertebral compression fractures, the most common site of insufficiency fractures is the pelvis and lower extremities. In the pelvis, the fractures usually occur in the ilium, the pubis and the ischium, but rarely in the fossa acetabuli. We report a severe insufficiency fracture of the fossa acetabuli in a 78-year-old woman with rheumatoid arthritis (RA). She had associated insufficiency fractures of the rib, the thoracic spine and the sacrum. In our case, senile osteoporosis was present before the onset of the fracture was recognized on radiographs, and RA and corticosteroid therapy might have further aggravated the porosis, resulting in the destruction of the fossa acetabuli. Regarding treatment for the fracture, a cemented total hip replacement without bone graft was attempted for several reasons such as the patient's activities, postoperative rehabilitation and the bone mass of the acetabulum. The postoperative course was satisfactory during study period. However, further follow-up is needed to monitor carefully how the patient will be in the future.

Acetabulum↗
PubMed1992

Revision arthroplasty using an anti-protrusio cage for massive acetabular bone deficiency.

Revision hip arthroplasty in patients with massive acetabular bone deficiency has generally given poor long-term results. We report the use of an 'anti-protrusio cage', secured to the ischium and ilium, which bridges areas of acetabular bone loss, provides support for the acetabular socket, and allows pelvic bone grafting in an environment protected from excessive stress. Forty-two failed hip arthroplasties with massive acetabular bone loss were revised with the Burch-Schneider anti-protrusio cage and evaluated after two to 11 years (mean five years). There was failure due to sepsis in five hips (12%) and aseptic loosening in five (12%); the remaining 32 hips (76%) showed no evidence of acetabular component failure or loosening.

Acetabulum↗
PubMed1997

The reliability of measurements of pelvic radiographs in infants.

We have evaluated the reliability of the measurement of radiological indicators in developmental dysplasia of the hip. Three observers each independently assessed 60 pelvic radiographs from infants aged from 3 to 36 months. Errors from the true value of a single measurement made by a single observer (E1), of the average of two measurements by a single observer (E2), and of the average of two single measurements by two different observers (E3) were established for the acetabular index of Hilgenreiner, for the assessment of superior and lateral femoral displacement and for indicators of pelvic alignment. The errors for the assessment of the acetabular index were E1 +/- 5 degrees, E2 +/- 5 degrees, and E3 +/- 3.5 degrees. There was a significant correlation between the presence of an acetabular notch on the radiograph and an increased error in measurement (p = 0.01). Yamamuro's measurement of lateral femoral displacement was more reliable than the Hilgenreiner distance. The errors of indicators of pelvic alignment showed a correlation with the age of the infant; the quotient of pelvic rotation was more reliable after seven months of age (p < 0.0001). The errors of the measurement of the symphysis os-ischium angle tended to increase with age and those of the measurement of the index of pelvic tilt decreased with skeletal maturation (p = 0.002).

Child, Preschool↗
PubMed1999

[Primary stability of press-fit acetabulum cups using a new acetabulum reamer].

The aim of the present study was to assess the initial stability of uncemented press-fit acetabular components using a newly developed reamer designed to optimize the surgical preparation of the acetabulum. Ten synthetic human pelves were used to investigate the stability of 20 uncemented press-fit acetabular components, each of which was tested in a servohydraulic testing machine for 6 cycles under an axial load of 2.4 kN. The results of the micrometric measurements revealed satisfactory stability for a reaming depth of 2 mm, and a press-fit of 2 mm. Micromotion was less than 200 microns in all the anatomical sections of the acetabulum (ischium 63 microns, pubis 150 microns, ilium 85 microns). A press-fit of 4 mm and the smaller reaming depth of 1 mm were associated with a substantial decrease in mechanical stability.

Acetabulum↗
PubMed2001

Initial stability of modular acetabular components. Comparative in-vitro study with polyethylene and ceramic liners.

Modular acetabular components with alumina ceramic liners are currently used in total hip arthroplasty, but concerns have emerged regarding their high stiffness, which could cause impairment of stability, stress-shielding phenomena, and loosening. The purpose of the present biomechanical investigation was to compare the in-vitro initial stability of a modular press-fit acetabular component using a polyethylene liner and using an alumina liner. The initial stability was investigated by measuring the micromotion between the implant and the acetabulum during the application of physiological load (2.39 kN). The micromotion of the acetabular component was investigated in 10 acetabuli using a polyethylene liner and in 10 acetabuli using an alumina liner. Micromotion was assessed at the level of the Os ilium, Os pubis, and Os ischium using 3 electromagnetic transducers. The transducers have a sensitivity of 1 micron and a range of measurement of 500 microns. All implants have been fixed on human pelves made of polyurethane. Measurement of implant micromotion showed stable conditions at the level of the three main sectors of the acetabulum during all tests. No statistically significant differences of results were observed between the group of specimens with polyethylene liner and the group of specimens with alumina liner. The mean micromotion values of the uncemented cups were similar to the mean micromotion values of 10 cemented cups investigated to achieve comparative data of stability. In conclusion, the modular acetabular components inserted using an alumina liner showed a satisfactory initial stability in-vitro. The results do not contrast with those achieved using the same cup inserted with a polyethylene liner.

Acetabulum↗
PubMedDate not supplied

Chondrosarcoma secondary to hereditary multiple exostosis treated by extended internal hemipelvectomy.

The authors report on the case of a 28-year-old patient with extensive chondrosarcoma of the left ischium and pubis involving hip joint, skin, and soft tissue of the gluteal region, secondary to hereditary multiple exostosis submitted to an extended internal Enneking type II and III hemipelvectomy. No prosthesis or arthrodesis was used. A few years ago, patients with extensive tumors like this one were treated with interilioabdominal amputation, resulting in a loss of quality of life. Two years after the limb-preserving surgery, this patient was disease free, with good functional results, including bipedal ambulation with support.

Adult↗
PubMed1996

Porous-coated acetabular components with screw fixation. Five to ten-year results.

The results of 136 consecutive primary total hip arthroplasties performed by one surgeon with the Harris-Galante-I porous-coated acetabular component were reviewed at a mean of seven years (range, five to ten years). In all hips, the outer diameter of the acetabular component was the same as the diameter of the final reamer used in the preparation of the acetabulum. However, this reamer was used only briefly at the rim of the acetabulum, and therefore the components had so-called press-fit stability. A mean of four screws (range, three to six screws) were used for additional fixation of the component. The clinical evaluation was performed with use of the Harris hip score. Standardized anteroposterior radiographs of the pelvis were assessed for migration of the component, radiolucent and radiodense lines, linear wear of the polyethylene, and osteolysis. No acetabular component had been revised for loosening and none were radiographically loose at the time of the most recent follow-up evaluation. There were no complications related to the use of the screws, and no screw had bent or broken. A non-progressive radiolucent line was seen in one acetabular zone in thirty-four hips (25 per cent) and in two acetabular zones in six hips (4 per cent). No hip had a radiolucent line in all three acetabular zones. The mean rate of linear wear of the polyethylene was 0.1 millimeter per year. There was no dissociation of the acetabular liner from the metal shell. Two hips (1 per cent) had asymptomatic osteolysis in the ischium and adjacent to the rim of the acetabular component; this was treated with grafting at the site of the lesion and exchange of the femoral head and the worn polyethylene liner. Five femoral components inserted without cement and one inserted with cement were revised because of loosening. The data suggest that, at a mean of seven years, fixation of this porous-coated component was uniformly excellent. The low prevalence of radiolucent lines and the absence of loosening are probably related, in part, to the technique of implantation. The low prevalence of polyethylene wear and pelvic osteolysis is a notable improvement compared with the results of arthroplasty with other porous-coated acetabular components. Although the results of the present study are encouraging, longer follow-up is necessary to determine the prevalence of late loosening and osteolysis.

Acetabulum↗
PubMed1999

Medial protrusio technique for placement of a porous-coated, hemispherical acetabular component without cement in a total hip arthroplasty in patients who have acetabular dysplasia.

Twenty-four hip replacements were performed with use of a medial protrusio technique to stabilize the fit of a hemispherical metal shell in the acetabulum in nineteen patients who had dysplasia of the hip. All of the hips were followed for a minimum of five years (average, seven years; range, five to thirteen years). Six of the hips were type I, seven were type II, eight were type III, and three were type IV according to the criteria of Crowe et al. The acetabular cup was implanted with the medial aspect of its dome beyond the Kohler line (drawn from the ischium along the ilioischial line) in all hips. An autogenous graft sculpted from the femoral head was used to cover 15 to 30 percent of the superolateral portion of the cup in one type-I hip, four type-III hips, and one type-IV hip. The need for these six bone grafts could have been avoided by reaming two to three millimeters more medially or by allowing 20 percent of the superolateral portion of the cup to be uncovered. Sixty to 84 percent of each bone graft was resorbed, effectively leaving the superolateral portion of the cup uncovered. The amount of the surface of the cup that was beyond the Kohler line averaged 41 percent for the six type-I hips, 43 percent for the seven type-II hips, 41 percent for six of the type-III hips, and 44 percent for one of the type-IV hips. Crossing of the ilioischial and iliopubic lines was noted on the radiographs of two type-III and two type-IV hips. Radiographs of two type-I hips and one type-II hip showed 7 to 17 percent of the surface of the dome of the cup through the internal pelvic wall (beyond the iliopubic line). None of the twenty-four metal shells were revised. A reoperation was performed on two hips to exchange a worn polyethylene insert, and three femoral components that had been fixed without cement were revised because of mechanical loosening. Wear averaged 0.26 millimeter per year in the fourteen hips that had a titanium femoral head and 0.09 millimeter per year in the nine hips that had a cobalt-chromium femoral head. The remaining hip had a ceramic femoral head, and the wear rate was 0.09 millimeter per year. The medial protrusio technique is a predictable, reproducible method for obtaining fixation of a porous-coated, hemispherical acetabular component in a dysplastic acetabulum. The technique permits the use of a porous-coated (bone-ingrowth) component; avoids the use of support bone graft and thereby reduces the operative time; facilitates rehabilitation by permitting earlier weight-bearing of the hip; and permits the use of a modular bearing surface, which may allow future exchange of only this surface rather than revision of the entire acetabular component because of excessive wear.

Acetabulum↗
PubMed2002

Survival and polyethylene wear of porous-coated acetabular components in patients less than fifty years old: results at nine to fourteen years.

BACKGROUND: Younger patients (those who are less than fifty years old) have been shown to have a high rate of failure of cemented acetabular components following total hip arthroplasty. In this report, we present the results associated with the use of an uncemented acetabular component in young patients who were evaluated at a minimum of nine years postoperatively. METHODS: Between December 1984 and December 1989, the senior author performed 174 primary total hip arthroplasties with use of a single design of porous-coated acetabular component. Seventy-one of these procedures were performed in fifty-six patients who were younger than fifty years old. Fifty-six of the seventy-one hips were available for radiographic and clinical analysis after a mean duration of follow-up of eleven years. All hips had been treated with a Harris-Galante-I porous-coated acetabular component that had been placed with a line-to-line fit and fixed with a mean of four screws. Clinical analysis was performed with use of the Harris hip score. Standardized anteroposterior radiographs were analyzed with regard to migration, radiolucent lines, pelvic osteolysis, and two-dimensional linear wear of the polyethylene. RESULTS: No metal shell was revised because of aseptic loosening, and no shell was loose at the time of the latest follow-up. A nonprogressive radiolucent line was seen in one zone in ten hips (18%) and in two zones in six hips (11%). No hip had a radiolucent line in all three zones. Pelvic osteolysis was noted in thirteen hips (23%); the osteolysis was observed in the ischium in eleven hips and around the screws in two. Survivorship analysis revealed that the probability of survival of the metal shell was 98% (95% confidence interval, 96.9% to 99.9%) at ten years. The mean rate of linear polyethylene wear (and standard deviation) was 0.15 +/- 0.10 mm/yr (range, 0.02 to 0.59 mm/yr). The wear rate was significantly increased in patients with an excellent Harris hip score (p = 0.004) and a younger age (less than thirty-eight years) (p = 0.026). With the numbers available, no relationship could be detected between the wear rate and the gender or weight of the patient, the polyethylene thickness, the abduction angle, or the femoral neck length. CONCLUSIONS: The fixation and survival of porous-coated acetabular metal shells in patients less than fifty years old was excellent after a mean duration of follow-up of eleven years. The high rate of linear polyethylene wear and the high prevalence of pelvic osteolysis are of serious concern in this patient population. Continued follow-up will be necessary to evaluate the influence of these findings on the longevity of the fixation of this prosthesis.

Acetabulum↗
PubMed2003

Radiographic definition of pelvic osteolysis following total hip arthroplasty.

BACKGROUND: Radiographs are the standard clinical tool used to monitor patients with pelvic osteolysis after total hip arthroplasty; however, previous reports have questioned the value and accuracy of this method. With use of a cadaveric model, we investigated the accuracy of radiographs in determining the location and size of periacetabular osteolysis. METHODS: We implanted total hip arthroplasty components in eight cadaveric hips and made four radiographs of each hip from different views. We then removed the components and created two pelvic defects in each hip. We measured the volume of each defect, reimplanted the components, and made another set of radiographs. The defects were then enlarged two more times, with the volume measured and another set of radiographs made each time. In total, 128 radiographs were made of forty-eight lesions. An orthopaedist who was blinded to the location of the lesions assessed the radiographs with regard to the presence and size of osteolytic lesions. RESULTS: The overall sensitivity for the detection of osteolysis on a single radiograph was 41.5%, and the overall specificity was 93.0%. Sensitivity was dependent on the location and size of the lesions but not on the radiographic view. Sensitivity ranged from 72% for lesions in the ilium to </=15% for lesions in the ischium and acetabular rim. The detection rate for lesions with a volume of >10 cm (3) was significantly higher than that for smaller lesions (p < 0.001). When all four radiographic views of one lesion were analyzed together, sensitivity increased to 73.6%. Despite the low sensitivity, specificity remained high, indicating that once osteolysis is evident radiographically, the likelihood that a lesion truly exists is high. Additionally, we found that the extent of osteolysis was substantially underestimated on radiographs. CONCLUSIONS: The use of radiographs to assess and monitor osteolysis has both limitations and merits. Using multiple views, an experienced orthopaedist identified only 73.6% of pelvic lesions. However, once a pelvic osteolytic lesion is evident radiographically, the likelihood that it truly exists is high.

Aged↗
PubMed1981

Avulsion injuries of the pelvis and proximal femur.

Twenty cases of avulsion fractures of the apophyses of the pelvis and proximal femur were reviewed. Most occurred in male adolescents engaged in active sports. Pain, often with little external evidence of trauma, was the most frequent presenting symptom. Conservative, nonsurgical treatment was successful in all the patients. The radiographic appearance of each type of apophyseal injury is demonstrated. Recognition of the initial deformity and of the patterns of repair is important to avoid unnecessary evaluation (tomography, radionuclide scans) and inappropriate therapy. While productive changes with healing are most likely to occur in the region of the ischium, any of the other sites may heal with abundant bone and may mimic neoplasm. In the proper clinical setting, bony changes at these sites should prompt the radiologist to consider a traumatic etiology.

Adolescent↗
PubMed1987

The widened teardrop distance: a plain film indicator of hip joint effusion in adults.

The teardrop distance is defined as the distance from the lateral margin of the pelvic teardrop to the most medial aspect of the femoral head as seen on anteroposterior pelvic radiographs. The structure responsible for the teardrop is the anteroinferior portion of the acetabular fossa with contributions from the ischium and from the superior pubic ramus. Anteroposterior pelvic radiographs of 10 patients with documented cases of unilateral hip effusion were retrospectively evaluated for teardrop distance widening on the affected side. Proof of the presence of hip effusion was based on the results of percutaneous hip joint aspirations as described in the patient's medical records. A teardrop distance widening of 1 mm or more was always consistent with hip joint fluid. In addition, radiographs from 20 patients with no known hip abnormalities were reviewed as a control population. These showed side-to-side symmetry in 16 cases (80%) and widening of less than 1 mm in the remaining four cases (20%). Thus, hip joint effusion in adults can be accurately diagnosed from plain radiographs in the presence of a teardrop asymmetry of 1 mm or more and in the absence of degenerative joint disease.

Adolescent↗
PubMed2002

MR imaging of popliteal pterygium syndrome in pediatric patients.

OBJECTIVE: Our purpose was to describe the use of MR imaging in the evaluation of the positions of the popliteal artery and peroneal nerve in children with popliteal pterygium syndrome for preoperative planning and to describe the typical appearance of popliteal pterygium on MR imaging. CONCLUSION: By depicting the popliteal artery and peroneal nerve either in normal positions or abnormally located immediately adjacent to the pterygium, MR imaging provides useful information for preoperative planning in children with popliteal pterygium syndrome. The MR appearance of a popliteal pterygium is that of a band of abnormal tissue extending from the ischium to the os calcis that has signal characteristics of fibrous tissue often attached to a belly of anomalous muscle.

Child, Preschool↗
PubMed2006

The effect of conformation on orthopaedic health and performance in a cohort of National Hunt racehorses: preliminary results.

REASONS FOR PERFORMING STUDY: There is a lack of scientific data and studies on the effect of conformation on performance or on orthopaedic health. OBJECTIVES: To investigate the relationship between conformation, injury and performance in racehorses used for racing over fences. METHODS: Over 2 years, 108 National Hunt racehorses were followed and their medical and performance data recorded. Conformation was measured in 3D with a computerised motion analysis system. Linear multiple regression models were used to evaluate the effect of conformation on measures of race performance and stepwise forward logistic regression models to assess the effect on risk of injury. RESULTS: An increase in intermandibular width, flexor angle of the shoulder joint and coxal angle (the angle between the ilium and ischium) was demonstrated to have a positive effect on performance. Performance decreased with increasing girth, length of the hind digit and valgus conformation of the metacarpophalangeal joint. The risk of suffering from superficial digital flexor tendon injury increased with increasing metacarpophalangeal joint angle and with carpus valgus conformation. The risk of pelvic fracture increased with valgus conformation of the tarsus and decreased with an increasing coxal angle. CONCLUSION: Valgus deformation was demonstrated to be detrimental to performance or increased risk of injury, perhaps resulting in higher loads on musculoskeletal structures. The coxal angle was the only parameter to have an effect on both risk of injury and performance. An alignment of the muscles with the axis of the pelvis may be beneficial for force transmission and decrease the bending moment of the muscles on the bones. The statistical power of this study is limited, however it provides preliminary data necessary for the planning of a larger scale study on the effect of conformation on performance and risk of injury. CLINICAL RELEVANCE: Studies of the effects of conformation on performance and risk of injury may aid in identifying individuals likely to perform well on the racecourse and avoid risks of injury.

Animals↗
PubMed1985

Radiographic evaluation of patients with Bechterew's syndrome (ankylosing spondylitis). Findings in peripheral joints, tendon insertions and the pubic symphysis and relations to non-radiographic findings.

One hundred and twenty-two consecutive hospitalized patients aged 35 years or more, and with definite radiographic bilateral sacro-iliitis were re-examined. All but 3 met established criteria for definite ankylosing spondylitis (AS). All peripheral joints from 114 of these patients were radiographed, and definite arthritis in one or several joints was demonstrated in 47 (41%) of them. The distribution pattern of arthritis was generally symmetric or slightly asymmetric. Articular new bone formation was a common finding in arthritic joints. The frequency of patients with hip arthritis was low (24% including patients with hip joint replacements); possible explanations include the selection of patients examined and difficulties in distinguishing between a primary osteoarthritis and osteoarthritis secondary to arthritis in a single radiographic examination in such patients. Although the hip joints were often severely affected, with extensive new bone formation, the erosions were generally small and protrusion of the acetabulum was not seen. Arthritis of the shoulder or of the hip was associated with an early onset of AS. Arthritis in the finger joints was associated with clinical psoriasis but was also a frequent finding in HLA B27-positive patients free from this condition (23%). Arthritic changes of small joints with extensive new bone formation ('egg in shell', 'pencil in cup' or 'gull wing' appearance) were seen in patients without clinical psoriasis. New bone formation of the ischium was frequent in HLA B27-positive patients (36%), but was not seen in HLA B27-negative patients. No differences concerning the frequency or severity of different radiographic pathologic changes recorded were observed between the sexes.

Adult↗
PubMed1985

Bechterew's syndrome (ankylosing spondylitis). A syndrome with distinct subgroups.

The results of tests for associations among radiographic findings of the dorsolumbar spine, peripheral joints, tendon insertions and the pubic symphysis are presented. Ankylosis of sacro-iliac joints, ankylosis of apophyseal joints, bridging syndesmophytes, ossified interspinous ligament, block vertebrae, arthritis of the pubic symphysis and new bone formation of the ischium were strongly mutually associated. They probably belong to the same subgroup of disease. Such findings were negatively associated with distal peripheral joint arthritis. Mixed osteophytes, parasyndesmophytes or shining corners (anterior spondylitis) showed associations suggesting that the etiology may be mixed. A late stage of sacro-iliitis, regressive changes, characterized by narrow joint spaces without extensive ankylosis and with minimal sclerosis (grade IV sacro-iliitis) was associated with distal peripheral joints arthritis, but negatively associated with signs of ankylosing processes of the dorsolumbar spine. On the basis of the radiographic findings, distinct subgroups of AS could be identified. These results confirm our previous results of an association pattern between clinical findings. We would also recommend that the grading system of sacro-iliitis put forward by Dale be adopted, since it turned out that this grading system often distinguished between distinct subgroups of this heterogeneous condition(s).

Adult↗
PubMed1989

Stress analysis of a total hip acetabular component: an FEM study.

A stress analysis of a total hip acetabular component was performed using three-dimensional finite element modeling. The model consisted of 548 four-noded quadrilateral shell elements with 582 nodes. A worst-case support condition was assumed in which bony contact with small areas of the ilium, ischium, and pubis was represented by three-point support. Loads corresponding to the peak pressures developed in the hip when rising from a seated position--the activity contributing most to the fatigue of a prosthesis--were applied to the model. Peak stresses of 490 MPa are predicted around a screw hole in the region of greatest loading; according to the fatigue curve for porous-coated Ti-6Al-4V alloy, this translates into a component life of three years. When the area of bony support for the prosthesis is increased by a factor of 1.5, the fatigue life is more than doubled to seven years. The addition of restraints around the loaded hole to represent the placement of a screw extends the lifetime dramatically to 65 years. Substituting the material properties of cobalt-chromium alloy increases the predicted lifetime of the component to twelve years. We conclude that poor bone support can compromise the service life of titanium alloy acetabular components. Furthermore, we suggest that screw fixation be used to secure the prosthesis in the anterior-superior region if the prosthesis is not well supported by bone in the acetabulum.

Acetabulum↗