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 purpose of this study was to investigate the gaps of bone-acetabular component interface, the initial mechanical stability and the effects of adjuvant screw fixation in the press-fitted two different shaped porous-coated acetabular components. Semi-hemispherical Harris-Galante II cup and full hemispherical Trilogy cup were press-fitted with or without adjuvant screw fixation in 40 bovine femur. The gaps of bone-implant interface were measured in each radiography of all specimen and axial compression tests and rotational stability tests were performed using servohydraulic tension-compression machine. There was significantly smaller gap at polar 1/3 region in the specimen implanted with Trilogy cup. But the adjuvant screw fixation did not affect the amount of gap. There was no significant statistical difference in axial load and rotational stability test in each situations of fixation. This study demonstrates that the initial mechanical stability is not influenced by the shape of semi-hemispherical Harris-Galante II cup and full hemispherical Trilogy cup and also independent of adjuvant screw fixation. But smaller gap of Trilogy cup at the polar 1/3 region indicates the possibility that less amout of wear debris of polyethylene or metal will be deposited and therefore less osteolysis or cup loosening will occur, but this hypothesis should be confirmed by the long-term clinical follow-up.
Acetabulum* ; Arthroplasty, Replacement, Hip* ; Femur ; Follow-Up Studies ; Osteolysis ; Polyethylene ; Radiography

PURPOSE: This study evaluated the minimum ten-year result of primary total hip arthroplasty with a non-cemented Multilock femoral stem. MATERIALS AND METHODS: Fifty five total hip replacements in forty-four patients using a non-cemented Multilock femoral stem and Harris-Galante 2 acetabular component were performed between January 1992 and December 1994. Forty-four hips in thirty-six patients were available for follow up for an average of eleven years (range, ten to twelve years). The clinical results were evaluated based on the Harris hip scores. A detailed radiography analysis was performed by an evaluation of the radiolucent lines, femoral osteolysis, and fixation stability by Engh Method. RESULTS: The average Harris hip score improved from 54.3 points preoperatively to 93.6 points postoperatively. Non-progressive radiolucencies < 2 mm in width were observed in nine (20.5%), and femoral osteolysis was observed in thirteen cases (29.5%). For the fixation stability, osseous ingrowth was noted in thirty nine cases (88.6%) and fibrous ingrowth was observed in two (4.5%). There were three (6.8%) cases with unstable fixation. Two hips underwent revision. The survival rate of the femoral component was 93.2% (forty one cases) after a minimum ten-year follow up. CONCLUSION: The non-cemented Multilock femoral component provided excellent clinical and radiographic results. However, the rate of femoral osteolysis was relatively high (mostly restricted to zone 1 and 7).
Acetabulum ; Arthroplasty, Replacement, Hip* ; Follow-Up Studies* ; Hip ; Humans ; Osteolysis ; Radiography ; Survival Rate

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

Computerized tomography has been used in the evaluation of the intracranial lesions. Recently the usage of computerized tomography has progressively widened in many fields of clinical practice. In orthopedics computerized tomography has been tried in the diagnosis and the determination of treatment of tumors, spinal disorders, hip disorders and knee problem. Four problem cases in which concentric reduction could not be obtained after closed reduction of hip dislocations were evaluated by computerized tomography from Apr, 1, 1983 to Mar. 31, 1984 in the Capital Armed Forces General Hospital and following conclusiions were obtained: 1. Open reduction revealed that muscles(adductor and pyriformis muscles), joint capsule and osteocartilaginous loose bodies (femoral and acetabular) were interposed to hinder concentric reduction. Large posterior acetabular fragment induced instability and redislocation of the hip. 2. When there were 2-3 mm lack of symmetry of the two femoral heads or any abnormal findings(breakage of Shenton's line etc.) in plain roentgenography, computerized tomography was recommanded, and muscles, osteocartilaginous loose bodies and instability were found. 3. Computerized tomography is an easy simple method and has a great diagnostic value in the evaluation of asymmetry and instability after closed reduction of traumatic hip dislocations.
Acetabulum ; Arm ; Diagnosis ; Head ; Hip Dislocation ; Hip ; Hospitals, General ; Joint Capsule ; Knee ; Methods ; Muscles ; Orthopedics ; Radiography