PURPOSE: To analyze the effects of implant design on the primary stability and the contact between bone and prosthesis of three different porous coated acetabular implants. MATERIALS AND METHODS: The distal part of sixty bovine femurs were employed. 52 mm acetabular cups were inserted tightly after 2mm under-reaming. Trilogy acetabular cups were inserted in Group I, Mallory head finned RingLoc cups in Group II, Duraloc spiked cups in Group III. The gaps between the acetabular cups and the bones were measured on the radiography. The axial compression test and rotation test were performed using Instron. RESULTS: The gaps between the acetabular cup and bone of Gorup I and II was significantly smaller than Group III at its central adjacent and peripheral area (p<0.05) . The gap at the mid-portion decreased in order of Group I, II and III (p<0.05) . At the rim of the acetabular cup there was no measurable gap in all three groups. In the axial load of 300Kp, the mean micromotions were no statistical significances among three groups (p>0.05) . The mean torque of 1 degree rotation test was higher in the Group III than in the group I and II without statistical significance (p>0.05) . The mean torque of 2, 3 and 5 degree rotation test was highest in Group II among three, but there were no statistical differences among three groups (p>0.05) . CONCLUSION: Triology and Mallory-Head cup can be assumed to have better primary stability than Duraloc cup. And additional fin or spikes attached on the acetabular implant couldn't enhance the primary bone-prosthesis interface stability.
Acetabulum* ; Femur ; Head ; Prostheses and Implants ; Radiography ; Torque

PURPOSE: This study analysed the incidence and the degree of an acetabular retroversion in a dysplastic hip. MATERIALS AND METHODS: 28 cases of dysplastic hips, in whom the CE angle was <20 degrees, and 20 cases of control group with a normal CE angle were enrolled in this study. Four cuts among the CT images (most superior cut of the femoral head, middle cut of the proximal half, middle portion, and middle cut of the distal half of the femoral head) were used to measure the acetabular anteversion. RESULTS: In the control group, anteversion of four cuts (form the cranial to caudal) were observed with an average of 4.1, 10.3, 16.5, 19.7degrees, and there was one case with a retroversion. In the dysplastic hips, the average anteversion angles were 4.4, 11.0, 17.9, 20.8degrees, and 9 cases with retroversion were discovered. In all cases showing retroversion, an overlapping of the acetabular anterior and posterior wall (cross-over sign) was observed on the simple pelvis AP radiography. CONCLUSION: There was a 32% incidence of acetabular retroversion, which was much higher than the control group (p<0.05). Therefore, in order to prevent an over-correction of the retroversion, which may cause impingement, the presence and the amount of retroversion must be recognized using CT before performing a periacetabular osteotomy.
Acetabulum* ; Head ; Hip* ; Incidence* ; Osteotomy ; Pelvis ; Radiography

We analyzed plain radiographs of 591 normal adult hips of various parameters to evaluate the radiological characteristics of the hip joint including the center-edge (CE) angle, acetabular angle, acetabular depth, acetabular roof obliquity and roof angle, and also to verify the rate of acetabular dysplasia. The CE angle was negatively correlated with acetabular angle and acetabular obliquity, but it was positively correlated with acetabular depth and roof angle. The rate of acetabular dysplasia (CE angle<20 degrees) was 1.8%. We concluded that the CE angle and acetabular angle are more useful parameters for the diagnosis of acetabular dysplasia because there was no significant difference with advancing age and gender, as well as relatively small standard deviations.
Acetabulum/radiography* ; Acetabulum/growth & development ; Adult ; Aged ; Aging/physiology ; Bone Diseases, Developmental/radiography* ; Female ; Human ; Korea ; Male ; Middle Age

In this study, the author presents the case of one patient who had a Harris-Galante total hip replacement for pigmented villonodular synovitis of the left hip joint, the locking system failed and separation of the polyethylene liner from the acetabular metal shell occurred while the closed reduction of the posterior dislocation of the femoral prosthesis was performed. This study indicates that the design of the acetabular assembly should be modified. The gap between the rims of metal shell and polyethylene liner should be reduced or eliminated.
Acetabulum*/radiography ; Hip Prosthesis* ; Human ; Male ; Middle Age ; Postoperative Complications/radiography* ; Prosthesis Failure ; Synovitis/surgery* ; Synovitis, Pigmented Villonodular/surgery*

Secondary osteoarthritis of hip joints is a common disease and is frequently followed by chronic sublexation and dislocation. Twenty four case of the secondary osteoarthritis associated with chronic subluxation and dislocation of the hip joints were evaluated with plain radiography and computed tomography. We retrospectively analyzed 1) the ossification and calcification of the acetabular labrum, 2) the thickeness of the quadrilateral plate of the ilium, and 3) anteroposterior diameter of the acetabulum. The changes of the hip joints in subluxation (n=14) revealed ossification of the acetabular labrum in 12 cases (86%), thickening of the quadrilateral plate of the ilium in 11 cases (78%) but anteroposterior diameter of the acetabulum was not changed. The changes of the hip joints in dislocation (n=10) revealed no evidence of the ossification of the acetabular labrum, thickening of the quadrilateral plate of the ilium in 10 cases (100%) and decreased anteroposterior diameter of the acetabulum. We conclude that CT findings of subluxation and dislocation of the hip joints can be helpful in the evaluation of the secondary osteoarthritis of the hip joints.
Acetabulum ; Dislocations* ; Hip Joint* ; Hip* ; Ilium ; Joints ; Osteoarthritis ; Osteoarthritis, Hip ; Radiography ; Retrospective Studies

OBJECTIVETo study the clinical significance of computed tomography (CT) in diagnosis and treatment of acetabular fractures.

METHODSThe plain and CT films of the 66 cases of acetabular fracture from January 2001 to June 2002 were analyzed retrospectively, and the radiological characteristics and results were compared to each other.

RESULTSThe diagnosis of 6 cases were changed after CT examination, and the occurrence ratio of marginal impaction, free body in joint, femoral head fracture, sacro-iliac injury and ischial tubersoity fracture involvement were 3:17, 7:29, 6:15, 0:5 and 1:5 in plain and CT examination respectively.

CONCLUSIONSCT examination has the determinative role in detecting weight-bearing zone, marginal impaction, free body, femoral head fracture, sacro-iliac injury, etc., and for completing the diagnosis and guiding the treatment. It should be the routine examination just as the three standard plain examinations in acetabular fractures, and should be carefully read.

The effect of acetabular augmentation with bone graft was reviewed in 12 patients with acetabular deficiency in total hip arthroplasty, performed between 1981 and 1984 at Hanyang University Hospital. Follow-up ranged from 12 to 18 months and averaged 23.3 months. Follow-up radiographs were analyzed. Based on radiography, all grafts were regarded as incorporated and equally successful with autogenous and allograft bone. Long-term follow-up evaluation revealed no evidence of progressive radiolucency or graft resorption. There was one sciatic nerve palsy after operation but recovered at 11 months later.
Acetabulum ; Allografts ; Arthroplasty, Replacement, Hip ; Follow-Up Studies ; Humans ; Radiography ; Sciatic Neuropathy ; Transplants

The clinical value of CT in the diagnosis of pelvic bone fractures is being explored. Conventional radiographic projections, including internal and external oblique views, although very helpful, often cannot provide sufficent jnformation to give a true sense of the fractures. CT conversely displays the anatomy in an axial plane, thereby providing the missing pieces of information and fascilitating classification of these fractures. From January 1983 to June 1986, 34 patients with pelvic bone fractures, admitted to Department of Orthopedic Surgery, Severance Hospital, were given both CT and conventional radiographs. Comparing the conventional radiographic findings with those of CT, the following conclusions were obtained. 1. For patients with multiple trauma who necessitate position changes during conventional radiography, no further change in position was required during CT. 2. CT clearly showed intraarticular loose bodies, anterior wall fractures of the acetabulum, and separations of the saicroiliac joint which were hardly detected on conventional radiographs. 3. CT permitted a better evaluation of the shape, extent, and degree of separation of fracture fragment, so it was very helpful in formulating the treatment plan. 4. Follow-up CT was helpful in evaluating the effectiveness of treatment.
Acetabulum ; Classification ; Diagnosis ; Follow-Up Studies ; Humans ; Joints ; Multiple Trauma ; Orthopedics ; Pelvic Bones ; Radiography

The major cause of early dislocation after total hip arthroplasty is malposition of acetabular cup. Therefore, radiographic evaluation of acetabular cup placement is essential in determining the postsurgical prognosis. The purpose of this study was to establish principles which would aid in checking the radiography. We evaluated 33 patients who were treated with total hip arthroplasty between Jan. 1988 and Aug. 1993 and investigated the methods of measuring the position of the acetabular cup on radiography using pelvic skeleton and acetabular cup. The results were analyzed as followings. l. After the total hip arthroplasty, the inclination of the acetabular cup shows average 37.1 degress in pelvis AP, 36.4 degrees in hip AP and 43.4 degrees in femur AP. This result means that the more X-ray beam focus is far from the acetabular cup, the more inclination of acetabular cup on radiography is incerased. 2. After the total hip arthroplasty, the difference of acetabular cup angle between pelvis AP and hip AP is average 0.7 degree, 6.4 degrees between pelvis AP and femur AP and 7.1 degrees between hip AP and femur AP. This result means that the more X-ray beam focus is far from acetabular cup, the larger difference between acetabular cup angle on radiography is.3. In experimental study with pelvic rotation, acetabular cup angle on radiography is average 45.7 degrees in neutral position, 42.8 degrees in 10 degree rotation, and 39.6 degrees in 20 degree rotation. This result means that the more rotation of pelvic bone is increased, acetabular cup angle on radiography is reversely diminished. 4. In experimental study with pelvic flexion-extension, acetabular cup angle on radiography is average 45.7 degrees in neutral position, 56.4 degrees in 20 degree pelvic flexion, and 32.3 degrees in 20 degree pelvic extension. This result means that when the pelvis is flexed, acetabular cup angle on radiography is increased, and when the pelvis is extended, acetabular cup angle is decreased than normal acetabular cup angle. 5. In experimental study with X-ray beams, acetabular cup angle on radiography is average 45.7 degrees in pelvis AP, 45.5 degrees in femur AP and 50.4 degrees femur AP. This result means that the more X-ray beam focus is far from acetabular cup, the more inclination of acetabular cup on radiography is increased. As the result of the study, radiographs which focus centered on hip demonstrated a nearly true representation of acetabular cup angle.
Acetabulum ; Arthroplasty, Replacement, Hip ; Dislocations ; Femur ; Hip ; Humans ; Pelvic Bones ; Pelvis ; Prognosis ; Radiography ; Skeleton

CT has been advocated as an adjunct to conventional radiography in the evaluation of pelvic bone fractures andtraumatic dislocations of the femoral head. Author compared and analysed the CT and plain radiographic findings of3 consecutive adult patients in whom acetabular or femoral head injuries were suspected or demonstrated on initialradiographs. The results were as follows; 1. CT was convenient and precise method in evaluation the patient withhip trauma. 2. CT was helpful in detecting intraaraticular osseous fragment, interposed soft tissue, and wideningof the joint space which was not evident on plain radiographs. 3. CT permitted better evaluation of asociatedinjuries in soft tissue and viscera in the plevic and retroperitoneal cavity, and also gave information aboutother associated fractures. 4. CT was superior for the evaluation of posterior acetabular rim and medial portionof the acetabulum. 5. CT was helpful for evaluating the presence or absence of intraarticular osseous fragmentsafter reduction of the dislocated hip.
Acetabulum ; Adult ; Craniocerebral Trauma ; Dislocations ; Head ; Hip ; Humans ; Joints ; Methods ; Pelvic Bones ; Radiography ; Viscera