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PubMed1999

Simplified 3D-evaluation of periacetabular osteotomy.

Reorientation osteotomies are widely used for the treatment of residual dysplasia of the hip. Preoperative planning is mandatory, and 3D-evaluation is of utmost importance for precise definition of direction and magnitude of displacement of the acetabulum. Instead of a 3D-CT scan reconstruction which needs multiple slices, we developed a 3D-reconstruction from a single AP pelvic view. This method is applicable if we accept that the femoral head and acetabulum are quite spherical. Appropriate software and a PC are used for this reconstruction that we compared with 3D CT-scan reconstruction and pelvic anatomical preparations. Twenty-two patients, 17 female, 5 male, with hip dysplasia, were treated by periacetabular osteotomy according to Ganz. The mean age was 27 years (14-40 years); the mean follow-up, 4.8 years (2-7 years). Four patients were treated conservatively in infancy for DDH, one patient had snapping hips associated with hip dysplasia, and two patients had slight sequellae of cerebral palsy. All patients were symptomatic mainly during daily activities or sports. The clinical evaluation was done using the Charnley scoring system. The Charnley score for pain improved from 3.6 (2-3.5) to 5.8 (5-6) at follow-up. No restriction of mobility or of walking capacity was observed after operation. The computer-assisted method also permits appreciation of the evolution of classical coxometry; i.e. Wiberg and Lequesne angles. The improvement after Ganz osteotomy was respectively 141% and 161% for Wiberg and Lequesne angles without any posterior uncoverage. The 3D-evaluation showed an improvement of 28% of the vertical projection area of the acetabulum on the femoral head. The anterolateral coverage improved from 20.3 to 50.1%. The Ganz osteotomy is really a 3D-reorientation osteotomy. With our simplified method it is possible to predict and control the amount of displacement to be done. However, we have to keep in mind that the articular cartilage is a limited crescent in the acetabulum; this method cannot replicate exactly the form and shape of articular cartilage. At this time it allows us to better control the amount of displacement during operation to avoid too large a displacement or lateralization.

Acetabulum↗
PubMedDate not supplied

[Biomechanical significance of the acetabular roof and its reaction to mechanical injury].

INTRODUCTION: The introduction of morphometry into the quantitative analysis of the bone system and functional adaptation of acetabulum to mechanical damages and injuries enabled a relatively simple and acceptable examination of morphological acetabular changes in patients with damaged hip joints. Measurements of the depth and form of acetabulum can be done by radiological methods, computerized tomography and ultrasound (1-9). AIM OF STUDY: The aim of the study was to obtain data on the behaviour of acetabular roof, the so-called "eyebrow", by morphometric analyses during different mechanical injuries. METHOD: Clinical studies of the effect of different loads on acetabular roof were carried out in 741 patients. Radiographic findings of 400 men and 341 women were analysed. The control group was composed of 148 patients with normal hip joints. Average age of the patients was 54.7 years and that of control subjects 52.0 years. Data processing was done for all examined patients. RESULTS: On the basis of our measurements the average size of female "eyebrow" ranged from 24.8 mm to 31.5 mm with standard deviation of 0.93 and in men from 29.4 mm to 40.3 mm with standard deviation of 1.54. The average size in the whole population was 32.1 mm with standard deviation of 15.61. Statistical analyses revealed high correlation coefficients between the age and "eyebrow" size in men (r = 0.124; p < 0.05); it was statically in inverse proportion (Graph 1). However, in female patients the correlation coefficient was statistically significant (r = 0.060; p > 0.05). The examination of the size of collodiaphysial angle and length of "eyebrow" revealed that "eyebrow" length was in inverse proportion to the size of collodiaphysial angle (r = 0.113; p < 0.05). The average "eyebrow" length in relation to the size of collodiaphysial angle ranged from 21.3 mm to 35.2 mm with standard deviation of 1.60. There was no statistically significant correlation between the "eyebrow" size and Wiberg's angle in male (r = 0.049; p > 0.05) and female (r = 0.005; p > 0.05) patients. The "eyebrow" length was proportionally dependent on the size of the shortened extremity in all examined subjects. This dependence was statistically significant both in female (r = 0.208; p < 0.05) and male (r = 0.193; p < 0.05) patients. The study revealed that fossa acetabuli was forward and downward laterally directed. The size, form and cross-section of acetabulum changed during different loads. Dimensions and morphological changes in acetabulum showed some but unimportant changes in comparison to that in the control group. These findings are graphically presented in Figure 5 and numerically in Tables 1 and 2. DISCUSSION: The study of spatial orientation among hip joints revealed that fossa acetabuli was forward and downward laterally directed; this was in accordance with results other authors (1, 7, 9, 15, 18). There was a statistically significant difference in relation to the "eyebrow" size between patients and normal subjects (t = 3.88; p < 0.05). The average difference of "eyebrow" size was 6.892 mm. A larger "eyebrow" was found in patients with normally loaded hip. There was also a significant difference in "eyebrow" size between patients and healthy female subjects (t = 4.605; p < 0.05). A larger "eyebrow" of 8.79 mm was found in female subjects with normally loaded hip. On the basis of our study it can be concluded that the findings related to changes in acetabular roof, the so-called "eyebrow", are important in diagnosis, follow-up and therapy of pathogenetic processes of these disorders.

Acetabulum↗
PubMed2000

[The effect of V-shaped nitinol alloy implantation on acetabular dysplasia: an experimental study].

OBJECTIVE: To observe the effect of V-shaped nitinol alloy implantation into the acetabular roof of puppies with acetabular dysplasia on acetabular dysplasia. METHODS: The puppies with acetabular dysplasia were divided randomly into two groups. Osteotomy was begun about 0.5 cm above the acetabulum, using a curved osteotome this cut must proceed between the medial wall of the ilium and medial wall of the acetabulum. The osteotomy does not have to be carried to the triradiate cartilage. When the osteotomy is completed, the superior aspect of the acetabulum can be hinged downward by curved osteotome. The V-shaped nitinol alloy was wedged securely in the osteotomy site. Roentgenogram was made 4 and 12 weeks after operation in all animals. RESULTS: The inclination of the acetabular roof was redirected and the acetabular index was decreased. Microscopic study showed a marked proliferation of cartilaginous cells of the acetabular cartilage. CONCLUSION: The V-shaped nitinol alloy implantation into the acetabular roof can correct the sloping acetabular roof, increase the coverage on the femoral head, and improve the growth of the acetabulum.

Acetabulum↗
PubMed2006

[Results of acetabular reconstruction with solid bone graft in primary and revision hip arthroplasty].

PURPOSE OF THE STUDY: To evaluate the results of acetabular reconstruction in total hip replacement and to compare them in view of the use of autologous or allogenic solid bone grafts. MATERIAL AND METHODS: The author evaluates a group of 48 total hip replacements carried out in the years 1990-1999, in which solid bone graft was used for reconstruction of an insufficient acetabulum. In 25 hips, the patient's own femoral head was used in primary surgery and, in 23 hips, a frozen femoral head from a tissue bank was used in revision arthroplasty. Most of the acetabular components used in this study were cemented. The patients were evaluated at 5- to 15-year follow-up. Each group was assessed separately and the results were divided into three categories according to X-ray and intra-operative findings, as follows: I. No radiographic evidence of cup loosening and incorporated graft II. Loosened cup and incorporated graft suitable for use in reimplantation III. Loosened cup and graft non-union or resorption RESULTS: In the autograft group, 80 % of the patients fell in category I and 12 % in category II; in the allograft group, 82 % of the patients were in category I and 9 % in category II. Complete failure, i.e., graft resorption and acetabular loosening, was recorded in 8 % and 9 % of group I and group II patients, respectively. Biopsy samples obtained during revision hip surgery showed good incorporation of both autografts and allografts. DISCUSSION: Other authors' views on the function of solid bone grafts after implantation and on methods of treating a defective acetabulum are discussed. The author puts the good outcomes shown in this study down to a careful implantation technique and thorough preoperative planning. CONCLUSIONS: By using a solid graft, the surgeon will achieve good primary fixation of a standard hip socket in a defective acetabulum and will make conditions for repair of defective bone tissue. The results imply that incorporation of both graft and acetabular component can be expected regardless of whether the graft is fresh or frozen. Although this method has its drawbacks and contraindications, it should be considered one of the options when planning total hip arthroplasty for an insufficient acetabulum.

Acetabulum↗
PubMed2006

[Impacted morsellized bone grafting in primary total hip arthroplasty for acetabular protrusion in patients with rheumatoid arthritis].

UNLABELLED: Between 1991 and 2002, we performed 156 primary total hip replacements in rheumatoid arthritis patients with protrusion acetabulum. The deficient acetabulum was reconstructed with autologous and allogous morsellized bone grafts from the femoral head. MATERIAL AND METHODS: Group 1 were 26 patients with reconstruction acetabulum deficient with autologous morsellized bone grafts and group 2 were 10 patients in witch we use allogous grafts. All patients were reviewed at an average follow-up of 5 years. The function of operated hips was determining according WOMAC, HHS and Merle-d'Aubigne-Postela scores. Incorporation of grafts was assessing according to Avci criteria. RESULTS: We found similarly good and very good results in both groups. Incorporation of allo- and auto- bone grafts was observed after average 26 months. In 1 hip we found porotic grafts but without of loosening of the acetabular component. CONCLUSION: This technique is a good option in cases with protrusion acetabulum due to rheumatoid arthritis.

Acetabulum↗
PubMed1990

Acetabular anatomy and the transacetabular fixation of screws in total hip arthroplasty.

An anatomical and radiographic study was undertaken to determine the safest zones in the acetabulum for the transacetabular placement of screws during uncemented acetabular arthroplasty. To avoid injury to intrapelvic structures, which are not visible to the surgeon during placement of the screws, cadavera were studied to define the location of these structures with respect to fixed points of reference within the acetabulum. Four clinically useful acetabular quadrants were delineated. The quadrants are formed by drawing a line from the anterior superior iliac spine through the center of the acetabulum to the posterior fovea, forming acetabular halves. A second line is then drawn perpendicular to the first at the mid-point of the acetabulum, forming four quadrants. The posterior superior and posterior inferior acetabular quadrants contain the best available bone stock and are relatively safe for the transacetabular placement of screws. The anterior superior and anterior inferior quandrants should be avoided whenever possible, because screws placed improperly in these quadrants may endanger the external iliac artery and vein, as well as the obturator nerve, artery, and vein. The acetabular-quadrant system provides the surgeon with a simple intraoperative guide to the safe transacetabular placement of screws during primary and revision acetabular arthroplasty.

Acetabulum↗
PubMed1990

[Prospective study on natural evolution of 99mTc-MDP bone scan in asymptomatic total hip arthroplasty].

Natural history of bone scan in forty three patients (55 joints) with asymptomatic total hip arthroplasty was evaluated. Bone uptake of 99mTc-MDP in regions of the acetabulum and femoral shaft, except the marginal acetabulum, became normal on one year post-operation. Radiographic detection of clear zone between bone and cement interface was common and increased with time after the arthroplasty. The post-operative natural change observed by radiography and scintigraphy at the site of the roof of acetabulum was statistically significant (p less than 0.01) by the chi-square test. This may imply that differentiation of true mechanical loosening from asymptomatic natural change at the site of the acetabulum in total hip arthroplasty is difficult. Our results presented here may help diagnosis of delayed complications in total hip replacement by bone scan.

Acetabulum↗
PubMed1988

Computed tomography evaluation of stability in posterior fracture dislocation of the hip.

Measurements of the percentage of remaining posterior acetabulum on computed tomography (CT) scan (the Acetabular Fracture Index) in posterior fracture dislocations of the hip were evaluated to determine the stability of the joint. All hips with less than 34% of the remaining posterior acetabulum were unstable. Hips with greater than 55% were stable. Between these values, hips were either stable or unstable. A statistical analysis demonstrated highly significant differences in the average remaining posterior acetabulum between the stable and unstable group. These findings were based on a review of 26 patients with posterior fracture dislocations of the hip (Epstein Type I-IV injuries) combined with CT scan analysis. The clinical status of hip stability was correlated with the Acetabular Fracture Index, and this provided the basis for the study. A simple linear measurement of the remaining posterior acetabulum on CT (the Approximate Acetabular Fracture Index) can be done easily by a physician, and this closely approximates the true remaining acetabular arc. Seven of ten unstable hips in 31 Epstein Type I-V patients showed femoral head subluxation of 0.5 mm or more on CT scan, whereas none of the 21 stable hips had demonstrable subluxation. Risk analysis provided a means of predicting hip stability for individual patients.

Acetabulum↗
PubMed1977

Premature closure of the triradiate cartilage. A case report and animal experiment.

Traumatic premature fusion of the triradiate cartilage is a rare complication of fractures of the pelvis in children. Only five cases were reported, leading eventually to subluxation of the hip. A case of premature closure of the triradiate cartilage where the injury occurred at the age of four years is reported. Severe hip subluxation with marked shallow acetabulum and widening of its medial wall was noted at the age of 15 years. Intrapelvic epiphysiodesis of the triradiate cartilage, without disturbing the hip joint, was performed in young rabbits, leading to thickening of the acetabular medial wall and subluxation of the hip. Fusion of the triradiate cartilage in young age leaves the growth plate inside the acetabulum intact, it continues to grow, displacing the acetabulum laterally. As the acetabulum becomes more shallow, the hip progresses to subluxation.

Acetabulum↗
PubMedDate not supplied

[Medial acetabular displacement and other pelvic displacements after Chiari osteotomy (author's transl)].

The authors have made a study of displacement after Chiari osteotomy in cadavers and in patients. In most of the cases, following osteotomy, there is movement not only at the pubic symphysis but also in the two sacro-iliac joints. Movement in the ipsilateral sacro-iliac joint is associated with upward and lateral displacement of the iliac crest giving an improved cover of the femoral head even though the acetabulum is not medially displaced. Movement in the controlateral sacro-iliac joint does result in medial displacement of the acetabulum but the whole of the opposite hemi-pelvis is also displaced so that the opposite acetabulum is displaced laterally and becomes more vertical. The authors attempt to draw conclusions on the biomechanical action of Chiari osteotomy on the opposite acetabulum.

Acetabulum↗
PubMed1983

Determination of sex with a discriminant analysis of new pelvic bone measurements: Part I.

The pelves of 100 black skeletons were measured on both sides for the following: (1) length from the superiormost aspect of the pubic symphysis to the nearest rim of the acetabulum (PS-A), (2) length from the highest point of the pubic tubercle to the nearest rim of the acetabulum (PT-A), (3) acetabular diameter (AD), (4) the vertical distance from the anterior aspect of the ischial tuberosity to the farthest rim of the acetabulum (IT-A), and (5) greatest femur head diameter. From these, three indices were derived: AD/PS-A (acetabulum/pubis index), AD/PT-A (acetabular diameter/pubic tubercle-acetabular rim index), and IT-A/PS-A (ischium-acetabulum height/pubic symphysis-acetabular rim index). The left AD/PS-A ratio and left IT-A height proved statistically to be of greatest discriminating value. Using these two variables, a discriminant function was derived which, followed by sorting with femur head diameter, accurately classified 97% of our sample. The acetabulum/pubis index alone with subsequent sorting by femur head diameter correctly assigned 96% of our sample. While this does not represent an improvement of predicatability over similar methods using the ischium/pubis index, measurements required for the acetabulum/pubis index are more easily defined and should, therefore, reduce the chance of observer error.

Acetabulum↗
PubMedDate not supplied

Hip arthroplasty by matching cups.

A total hip surface arthroplasty consisting of matching cups and uncemented prosthetic components is a noteworthy operation. The femoral cup obtains cylindrical support from the femoral head which is reamed in the shape of a cylinder. The acetabular cup is metallic with a polyethylene liner. It is mobile over the bone but its position is constrained by contact with the femoral cup and therefore "self-centering." On the femoral side, the cup must be placed strictly in the axis of the femoral neck. The main consideration in femoral head surface replacement is the vitality of the underlying bone. Necrosis was observed in the earliest clinical trials but there have been no cases of necrosis in the past 3 1/2 years. This is attributed to a more limited surgical approach in which only the anterior part of the gluteus medius is divided and all the posterior elements of the hip are preserved. The acetabulum is sufficiently reamed to receive the cup, which protrudes beyond the external margins of the acetabulum in all positions. Errors have been committed while perfecting the prosthetic material, but the results as determined by a 6 1/2 year follow-up on purely metallic cups are encouraging. Metal-polyethylene cups presently under investigation have almost a 2 year follow-up. The reaction of the acetabulum to an uncemented cup is not yet known. However, the existence of 2 sliding surfaces and the fact that the acetabular cup moves only during the extremes of hip movement, is reason to assume that if the acetabulum is not reamed to expose cancellous bone, the risks of protrusion are minimal or delayed. Total surface arthroplasty by concentric cups has been performed in 335 hips to date. The operation is especially recommended when osteotomy is no longer possible and disabling coxarthrosis is present in relatively young patients.

Acetabulum↗
PubMedDate not supplied

The treatment of severe acetabular osteolysis by bone grafts and cementless techniques.

The authors describe their experience in the treatment of severe acetabular osteolysis using bone grafts and cementless screwed acetabulum. They define the criteria that directed them towards this choice and the surgical method used in relation to bone loss caused by failure of the previous prosthesis. In light of their experience, the advantages and the drawbacks to using a cementless acetabulum in hip reimplantation are described, with particular analysis of the peculiar features of the P.M. acetabulum that, because it is screwed and has a truncated-conical design, permits stabilization of the grafts without the use of further instrumentation, and obtains effective primary stability even when there is discontinuity of the bottom or of the acetabulum.

Acetabulum↗
PubMed1998

[Acetabular reconstruction using bone allograft in the revision of total hip prosthesis].

PURPOSE OF THE STUDY: Aseptic loosening of the acetabular component is the most worrying problem after hip arthroplasty. During revision surgery we prefer to rebuild a solid bony acetabulum close to the anatomy in which the implant will be cemented. On the basis of the first 48 acetabular reconstructions using deep-frozen bony allografts, we carried out a review of our results in a pathology which will surely increase in the future. MATERIAL: 48 hips were operated according to this technique. It has been possible to review 38 of them, with an average follow-up of 7.3 years (extremes 5 years, and 9.6 years). The average age of the population at the time of surgery was 63 years. Two etiologies predominated: congenital hip dislocation sequelae and primitive hip arthritis. In 10 cases of massive deterioration, a Muller's ring was used to stabilize the allograft. METHODS: The results were analyzed at 6 months, 2 years, 4 years, and at maximum follow-up, clinically, according to Merle d'Aubigné grading system. Radiologically, Ranawat's criteria were used to assess the re-centering of the reconstructed hips. The development of radiolucent lines and implants migration were also assessed. RESULTS: Clinically, the patients' comfort was always improved by pain relief. Radiologically, average acetabular upward migration of 5 mm and medialisation of 3.5 mm were observed. 24 hips presented radiolucent lines. 19 radiolucent lines were below 2 mm. 5 were greater than 2 mm and leaded to loosening. In 4 of these 5 cases of radiolucent lines, there were acetabular migrations with failure. The radiological image remained stable afterwards. In these cases there was a real loosening, necessitating further surgery. In all cases, partial resorption of the graft was observed. DISCUSSION: Study of our first 38 cases shows that bony allograft and cemented acetabulum, sometimes including an armature, is one possible solution to the problem of difficult acetabular reconstructions. However, with an average follow-up of 7.3 years, we already have 5 (13 per cent) aseptic acetabular loosening, of which one has been operated on. Radiological analysis of these does not question the allograft, but rather imperfect re-centering. Analysis of the good results, 33 (87 per cent) stable acetabulum indicates re-fixing in quasi-anatomical position, in conditions close to those of a first time arthroplasty, with the aid of perfectly stabilized bony transplants, and where contact with the receiver acetabulum is maximal. CONCLUSION: Our follow-up is one of the longest in literature. But with a migration rate already of 13 per cent, it is not yet sufficient for us to be permanently assured about the future of our patients, even if their age is greater and their activity less than those of patients having a first hip arthroplasty.

Acetabulum↗
PubMed1978

[Treatment of coxa magna in Perthes disease by pelvic osteotomy (author's transl)].

In M. Perthes a progressive deformation and flattening of the epiphysis is caused by the stress in the hip. In the beginning stages a varisation osteotomie gives a sufficient reduction of the joint pressure and a modelling of the enlarged head by the acetabulum is possible. In later stages a detoriation of the head deformity with fixed adduction contracture can be caused by varisation osteotomie. Enlarging the acetabulum laterally and ventrally and medializing the hip-joint by means of a Chiari pelvic-osteotomy reduces the joint pressure so far, that a restitution of the hip joint with round and congruent joint surfaces can be expected. A lateralisation of the deformed femoral head with a secondary insufficiency of the acetabulum should also be treated by an additional pelvic osteotomy, if in the arthrography the lateral part of the head does not enter the acetabulum in abduction position. In secondary osteochondritis in hip luxation the treatment should be equal. Even an advanced secondary osteoarthritis after M. Perthes could be stopped by pelvic osteotomy over years.

Adolescent↗
PubMed2003

Cytoskeletal 10 nm filaments in cells of the algal phyla Chlorophyta, Charophyta, and Chrysophyta and their developmentally regulated and species-specific association with prosomes.

10 nm diameter filaments were observed in whole-mount preparations of algae of diverse phyla: Acetabularia acetabulum and A. major (Chlorophyta), Chara australis and Nitella flexilis (Charophyta), and Poterioochromonas malhamensis (Chrysophyta). A polyclonal antibody raised against a basic, 50 kDa DNA-binding protein of A. acetabulum stains the filaments of A. acetabulumand and A. major as well as of C. australis and N. flexilis. While in the perinuclear region of A. acetabulumand and A. major and throughout the cytoplasm of P. malhamensis the 10 nm filaments have a smooth appearance, in the stalk of A. acetabulumand and A. major they are densely covered by globular structures; in C. australis and N. flexilis they are less frequently associated with such material. The morphology of a part of the globular particles is quite reminiscent of prosomes. A monoclonal antibody elicited against prosomes isolated from A. acetabulum indeed decorates the globular particles on the A. acetabulum and A. major filaments. The possible role of these filament-particle associations is discussed.

Characeae↗
PubMed2005

[Femoral neck fracture complicating orthopedic reposition of a dislocated hip: four cases].

Posterior dislocation of the femoral head with fracture is an exceptional hip injury. Emergency reduction is required. Reposition into the acetabular cavity of the dislocated femoral head may not be feasible. Irreducibility, instability, and more rarely accidental fracture of the femoral neck may also occur. We encountered this latter complication in four patients and report here its frequency and mechanism and propose preventive therapeutic measures. Seventy dislocations and fracture-dislocations of the hip were treated in our unit from March 1997 to February 2003. Among these cases, fourteen hip dislocations were complicated by femoral head fractures. Fracture of the femoral neck occurred during reduction in four. All four cases occurred in men, mean age 49.7 years, who were traffic accident victims (drivers or passengers). There were two Pipkin IV fracture-dislocations and two Pipkin II. The first reduction, achieved under general anesthesia in an emergency setting, was performed by an orthopedic surgeon in one patient and a general surgeon in three patients. Arthroplasty was used to treat the femoral neck fracture in three patients and pinning in one. We reviewed retrospectively the clinical and imaging data before and after reduction. Sub-capital fracture situated 4.0 cm (mean, range 3.5-4.5 cm) from the lesser trochanter occurred in all four cases. The head remained attached above and posteriorly to the acetabulum and was rotated less than 90 degrees . The fragment remaining in the acetabulum was displaced in two cases. In one patient, the fracture-dislocation of the head was associated with a fracture of the posterior rim of the acetabulum. This complication appears to result from an abrupt inappropriate reduction movement. The neck fracture would occur when capsulomuscular retention of the femoral head is associated with a head defect which catches on the rim of the acetabulum during the reduction movement. Neck fracture during reduction of traumatic hip dislocation is a serious complication. Prevention of this iatrogenic event requires a slow, progressive reduction limiting the trauma to a minimum; first intention open surgery may be required in selected cases.

Accidents, Traffic↗
PubMed1993

Pressurization of bone cement under standard, flanged and custom acetabular components for total hip replacement.

Custom acetabular components are proposed to achieve uniform cement mantles, even in irregular acetabula presented at revision, in order to enhance fixation. One aim of developing custom components was to permit pressurization of bone cement by the components at insertion and maintain the pressure during polymerization. A model acetabulum was set up for the insertion of standard, flanged and custom components under constant force. Cement pressure was measured at the floor of the acetabulum by means of a piezoelectric diaphragm transducer. Polythene tubes were inserted in the model acetabular walls to estimate penetration of cement into cancellous bone. Insertion of the standard and flanged components caused cement pressures up to 106 kPa which decayed to less than 21 kPa as cement escaped at the rim and the components came into contact with the acetabulum. The custom component maintained a pressure of over 60 kPa during polymerization from an initial pressure of 105 kPa and examination of cement mantles on removal showed no evidence of contact. The custom component also showed enhanced penetration of cement, especially around the rim of the acetabulum. It is concluded that the custom component design achieves higher cement pressures and that better fixation will result.

Bone Cements↗