Acetabular Region Research Articles

Cartilage lesions in the hip: diagnostic effectiveness of MR arthrography.

To evaluate the diagnostic performance of magnetic resonance (MR) arthrography in the detection of articular cartilage lesions in patients suspected of having femoroacetabular impingement and/or labral abnormalities. Forty-two MR arthrograms obtained in 40 patients with a clinical diagnosis of femoroacetabular impingement and/or labral defect were retrospectively analyzed. Two readers independently interpreted the images for cartilage lesion location, depiction, and characteristics. Within 6 months after MR arthrography, each patient underwent open hip surgery, during which the entire cartilage of the hip joint was inspected. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. kappa values were calculated to quantify the level of interobserver agreement. At surgery, most (37 [88%] of 42) cartilage defects were identified in the anterosuperior part of the acetabulum. In 23 (55%), 12 (29%), 10 (24%), and 10 (24%) hips, lesions were found in the posterosuperior acetabulum, anteroinferior acetabulum, posteroinferior acetabulum, and femoral head, respectively. The sensitivities and specificities of MR arthrographic detection of cartilage damage in all regions combined were 79% (73 of 92 regions) and 77% (91 of 118 regions), respectively, for reader 1 and 50% (46 of 92 regions) and 84% (99 of 118 regions), respectively, for reader 2. At interobserver comparison, agreement was fair (kappa = 0.31) for detection of cartilage lesions in the femoral head and poor (kappa <or= 0.2) for detection of lesions in all acetabular regions. Cartilage lesions are common in young and middle-aged patients with femoroacetabular impingement and/or labral abnormalities and are most frequently found in the anterosuperior part of the acetabulum. 2003

Idiopathic osteonecrosis of the femoral head in the elderly.

Idiopathic osteonecrosis of the femoral head (ION) is a disease prevalent in adulthood, and its development in elderly persons is known to show a low incidence. To clarify its characteristics in elderly patients, radiological and histological examinations were performed on 18 patients aged 60 years or older histologically diagnosed as having ION. On roentgenography, three characteristic points were observed, 1) progress of collapse in the femoral head within a short period (12 cases, 66.7%), 2) narrowing in the joint space within a short period (6 cases, 33.3%), and 3) rapid destruction and resorption of the femoral head (4 cases, 22.2%). The lesion expanded to the acetabular region, and a course similar to that of so-called rapidly destructive coxarthrosis (RDC) was developing in 3 cases (16.7%). However, in these 3 cases, changes in the acetabular region were mild, compared with ordinary RDC, and they were considered different from common RDC. These radiological characteristics were found more clearly in women than in men. In the histopathological examination, severe degeneration in the cartilage of the femoral head was found, while wide infiltration of repairing tissue into the necrotic area was seen from the early stage. When necrotic trabecula were collapsed markedly and degraded severely, then destruction and resorption of bone expanded to non-necrotic regions in some cases. Osteogenic sclerotic line (the demarcation line), which has been often seen in ordinary ION, was not developed in most cases. These characteristics were more prominent in women.

Anatomical changes in the pelvis after modified Chiari pelvic osteotomy.

Although plain X-ray analysis is able to reveal anatomical changes in the frontal plane of the pelvis after Chiari pelvic osteotomy involving medial displacement (medialization) in the distal fragment and lateral displacement (lateralization) in the proximal fragment, changes in the horizontal or sagittal plane can not be discerned. Here, I have investigated three dimensional changes in the pelvis using CT in 22 patients before and after Chiari pelvic osteotomy. The various changes were investigated. Medialization in the distal fragment (average 0.4 cm) occurred in the 14 cases and to a slight extent in the other 8 cases. Also anterior or posterior displacement, and anterior rotation occurred in the distal fragment. Lateralization in the proximal fragment (average 0.8 cm) occurred in 19 cases and to a slight extent in the other 3 cases. Furthermore, the acetabular coverage over the femoral head, assessed by superimposing the acetabular region over the femoral head, improved by about 30% of the anterior half of femoral head and by about 20% of the posterior half of femoral head. It is suggested that the acetabular coverage over the femoral head is most affected by lateralization in the proximal fragment.

Lissorchis macropharynx n. sp. (Digenea: Lissorchiidae) from the Shorthead Redhorse, Moxostoma macrolepidotum (Lesueur) (Osteichthyes: Catostomidae)

Lissorchis macropharynx (Digenea: Lissorchiidae) is described from the shorthead redhorse, Moxostoma macrolepidotum (LeSueur) (Catostomidae) from the Assiniboine River drainage of southern Manitoba. The species is morphologically similar to Lissorchis hypentelii in possessing a similar body shape (widest at the ovarian region and a relatively long hindbody), a distinctly trilobed and relatively posteriorly situated ovary, and in the distribution of the vitellaria. It differs from L. hypentelii and all other lissorchiids in possessing a massive pharynx that is generally equal in length to or longer than the oral sucker and almost as deep as the cervical region of the body it occupies, a protruding acetabular region with an aspinose ridged/folded and grooved anterior surface, and a massive cirrus sac that reaches the level of the ovary. Museum specimens of Lissorchis spp. from M. macrolepidotum from other drainages in Manitoba and Wisconsin were also identified as L. macropharynx.

Biomechanical consequences of anterior column fracture of the acetabulum.

To measure biomechanical consequences of a high anterior column acetabular fracture. A benchtop biomechanical model using quasi-static loading of the hip joint in a simulated single-leg stance. Pressure-sensitive prescale (Fuji) film was used to determine hip joint loading parameters. Six cadaveric hemipelvi with one hip tested in each specimen. Three right and three left hips were tested. Creation of an anterior column fracture with anatomic reduction and fixation, followed by gap malreduction/fixation, and subsequently step malreduction/fixation. Contact pressure, contact area, and load distribution throughout the hip joint in each experimental condition. There were significant increases in load (p<0.01) and peak pressures (p<0.01) in the superior acetabular region after gap malreduction and in peak contact pressures after step malreduction (p<0.01) as compared with the intact acetabulum. Anatomic reduction was not associated with increased mean or peak contact pressures (in any region). Both step and gap malreductions of a high anterior column fracture resulted in significantly increased peak contact pressures in the superior acetabular region. These biomechanical data cannot be directly extrapolated to clinical applications, but these data suggest that anatomic reduction of anterior column fracture affords the best opportunity to restore contact pressures, contact area, and load distribution within the hip to levels similar to those seen in the intact acetabulum.

Results of Total Hip Arthroplasty For Crowe Type III Developmental Hip Dysplasia

From 1969 through 1980, 90 hips in 82 patients had cemented total hip arthroplasty for Type III developmental hip dysplasia. Seventy hips were reviewed at an average of 16.6 years (range, 5-23 years) after operation. Aseptic loosening developed in 53% of acetabular cups and 40% of femoral stems. Despite attempts to place acetabular components in the anatomic center, 18 cups (25.7%) were placed outside that area. Using a measurement method to determine the true acetabular region and approximate femoral head center, final acetabular loosening strongly correlated with initial cup placement. Loosening occurred in 15 of 18 cups (83.3%) initially positioned outside of the true acetabular region compared with loosening in 22 of 52 cups (42.3%) initially positioned within the true acetabular region. Acetabular loosening also correlated with initial lateral displacement or initial superior displacement of the hip center from the approximate femoral head center. Initial cup placement medial to the approximate femoral head center was predictive of successful long term acetabular component fixation. The method of acetabular reconstruction did not affect eventual cup loosening. Placement of the hip arthroplasty center of rotation in or near the true acetabular region is recommended.

Vascular lesions in surgery of the hip joint

The vascular anatomy in the acetabular region involves a certain risk of arterial and venous injuries complicating orthopaedic surgery. These complications have been grouped into four categories: lacerations, thrombosis, pseudoaneurysms and arteriovenous fistula. In a period of 5 years, three injuries of the external iliac artery and four lesions of the femoral artery associated with total hip arthroplasty were treated surgically at the Department of Vascular Surgery of the University Hospital in Graz. In one case a concomitant lesion of the pelvic vein was observed. The incidence of iatrogenic vascular injuries in total hip surgery is 0.3%. Combined injury of the external iliac artery and vein led to a life-threatening bleeding complication. The vascular lesion became manifest as acute ischaemia of the lower extremity or as an acute haemorrhage 30 min to 2 h after primary surgery. The late complication of a false aneurysm of the femoral artery occurred in one patient 3 weeks after total hip replacement. Reconstruction of the vascular lesions was performed by direct suture, except that two arterial lesions required the use of polytetrafluoroethylene (PTFE) vascular grafts. Vessels in the pelvic region are at high risk if screw fixation acetabular components are used. Perforation of the iliac artery by protruded methylmethacrylate polymer components of cement has been documented. The obturator vessels are in a vulnerable position if the acetabular floor has been broached by operative instruments or eroded by loosening of the prosthesis facilitated by osteoporosis, steroids or sepsis. Femoral vessels are endangered by Hohmann retractors that are not placed directly on bone. Though vascular injury during hip operations is rare, recognition of such complications is important as safe and satisfactory treatment can be achieved. Rapid identification and immediate surgical repair of these lacerations are essential for their management.

The Effect of Superior Placement of the Acetabular Component on the Rate of Loosening after Total Hip Arthroplasty. Long-Term Results in Patients Who Have Crowe Type-II Congenital Dysplasia of the Hip*

A method for measurement of the true acetabular region and the approximate femoral head center as well as a classification consisting of four zones for assessment of the acetabular position of the acetabular cup were used to analyze the results of primary total hip arthroplasty with cement in 117 patients (145 hips). All patients had Crowe type-II congenital dysplasia of the hip. The mean age at the time of the arthroplasty was fifty-one years (range, fifteen to seventy-six years), and the mean duration of follow-up was fourteen years (range, two to twenty-two years). The initial position of the acetabular cup outside of the true acetabular region and outside of zone 1 (inferior and medial) was associated with an increase in the rates of loosening (p < 0.05) and revision (p < 0.04) of the femoral components. Cups that initially were more than fifteen millimeters superior to the approximate femoral head center, without lateral displacement, were associated with an increased rate of loosening (p < 0.001) and of revision (p < 0.04) of the femoral components as well as with an increased rate of loosening (p < 0.002) and of revision (p < 0.01) of the acetabular components. These findings suggest that superior positioning of the acetabular component, even without lateral displacement, leads to increased rates of loosening of the femoral and acetabular components. An attempt should be made to position the acetabular component in or near the true acetabular region.

Curative local control of malignant tumors in the acetabulum by intraoperative radiotherapy.

As treatment for malignant tumors in the acetabular region of the pelvis, radiotherapy, mainly in the form of intraoperative radiotherapy (IORT), was carried out in four patients. One had a malignant fibrous histiocytoma of bone and three had metastatic tumors from the stomach and lung. Over follow-up period, ranging from 3 to 46 months, satisfactory limb function was preserved in three patients; the fourth suffered from femoral nerve palsy as a complication of IORT. Cessation of growth was observed radiologically in all the tumors, and curative local control was proven histologically in two patients at autopsy.

Anatomic and Radiographic Considerations in the Placement of Anterior Pelvic External Fixator Pins

Anatomic and radiographic studies were performed on three cadaveric pelves to define recommendations for better anterior pelvic external fixator pin placement. A thick zone of bone was identified for pin purchase beginning along the iliac crest 2-3 cm posterior to the anterior superior iliac spine (ASIS), and extending 6-8 cm posteriorly along the crest. This zone is hourglass-shaped, and follows the superior gluteal ridge to the superior acetabular region. This zone has a maximal thickness of 4 cm in the supra-acetabular region, and a minimum of 8 mm at the isthmus. Cortical pin penetration is more likely to occur if pin placement begins in the lateral third of the iliac crest, or if the pin is advanced beyond the isthmus of this zone, 5 cm from the crest. Acetabular penetration occurs when the pins are advanced farther than 10.5 cm. Radiographic evaluation demonstrates that only the pelvic outlet view gives the proper orientation of the iliac tables to guide the angle of the pin placement (24 degrees from vertical) and to confirm proper pin placement. Computed tomography (CT) evaluation with "inlet" positioning of the gantry gives complementary information for pin placement.

Computer simulations of stress-related bone remodeling around noncemented acetabular components

The authors have used computer modeling techniques to examine stress-related bone changes in the acetabular region. Using a previously developed theory for bone development and adaptation, the authors simulated the distribution of bone density in the natural pelvis as well as changes in bone density following total hip arthroplasty. The geometry of the finite element model was based on a two-dimensional slice through the pelvis. Starting from a solid, homogeneous structure, the computer simulations predicted the distribution of bone density throughout the natural pelvis. The predicted bone density distribution in this first simulation agreed well with the actual bone density distribution only when loads representing multiple activities were incorporated. Using the predicted density distribution as a starting point the authors modified the finite element models to study two designs of noncemented, metal-backed acetabular cups. The simulations with fully fixed bone-implant interfaces predicted extensive loss of bone density medial and inferior to the prosthetic components. The simulations with loose interfaces led to more moderate losses of bone density, indicating a load transfer more similar to that which occurs in the natural joint. The differences in simulated bone remodeling between the two component designs were quite minimal. These results indicate that acetabular components with full bony ingrowth may induce significant stress-related bone remodeling due to a nonphysiologic transfer of load.

Assessment of the vertebral fracture treshold in spanish population by dual-energy x-ray absorptiometry (DEXA)

The authors have used computer modeling techniques to examine stress-related bone changes in the acetabular region. Using a previously developed theory for bone development and adaptation, the authors simulated the distribution of bone density in the natural pelvis as well as changes in bone density following total hip arthroplasty. The geometry of the finite element model was based on a two-dimensional slice through the pelvis. Starting from a solid, homogeneous structure, the computer simulations predicted the distribution of bone density throughout the natural pelvis. The predicted bone density distribution in this first simulation agreed well with the actual bone density distribution only when loads representing multiple activities were incorporated. Using the predicted density distribution as a starting point the authors modified the finite element models to study two designs of noncemented, metal-backed acetabular cups. The simulations with fully fixed bone-implant interfaces predicted extensive loss of bone density medial and inferior to the prosthetic components. The simulations with loose interfaces led to more moderate losses of bone density, indicating a load transfer more similar to that which occurs in the natural joint. The differences in simulated bone remodeling between the two component designs were quite minimal. These results indicate that acetabular components with full bony ingrowth may induce significant stress-related bone remodeling due to a nonphysiologic transfer of load.

Ten- To 14-Year Results of a Ceramic Hip Prosthesis

One hundred total hip arthroplasties with a cementless aluminum oxide socket and ball with different types of cemented metal femoral stems were performed from 1974 to 1979. All were primary implantations. These cases were recently reviewed in a ten- to 14-year follow-up evaluation. Despite extensive laboratory testing of the ceramic material, a significant number of cases resulted in a very unfavorable result such as extensive wear, ball fracture, or migration of the socket. Whereas the patients had died or could no longer be traced in the case of 23 prostheses, there were 25 prostheses that had already been exchanged at the time of review for mechanical reasons (two stem fractures, eight ceramic ball fractures) and for component loosening attributable to wear of the alumina components. The remaining 52 prostheses still in place had good clinical results in 80%. However, roentgenographic evaluation of these prostheses revealed signs of loosening in six femoral components and in three sockets. Migration of more than 5 mm was evident in 24 sockets (46% of surviving prostheses). Although this had caused loosening in only three sockets at the time of review, further migration up to the limits of the acetabular region would be a major reason for future failures.

Procedures for analysis of strain transfer in the acetabular region in vitro

The failure of acetabular cups via loosening, migration or fracture is partially related to the stress distribution existing in the acetabular region. The complexity of the investigation of these stresses demands the application of a variety of model testing techniques involving combined embedded strain gauging, finite element analysis, transmission and reflective photoelasticity and crack propagation studies. The application of these procedures are described and the difficulties of obtaining representative loadings and restraints are commented upon.

Azetabulumplastik nach Lord bei großen Knochendefekten durch Lockerung von Hüftendoprothesen

Acetabular plasty after Lord enables revision even of major failures. In all cases treated by us the homologous bone graft consolidated. In some cases there was a medial and vertical protrusion due to considerable absorption. After an average follow-up period of 1 year and 9 months the patients did not feel any pain; the extent of mobility was good, but the walking ability was restricted, in most cases due to additional problems. Fundamentally, a new acetabulum can be regrafted in all patients. So far this operation had not been necessary because of the absence of pain. In our opinion acetabular plasty after Lord is an alternative to the Girdlestone situation. The alternative of a massive allograft of the acetabular region will have to prove its worth in the future.

Case report 596

* Supported in part by VA Grant =~ SA306 Address reprint requests to: Donald Resnick, M.D., Department of Radiology, VA Medical Center, 3350 La Jolla Village Drive, San Diego, CA 92161, USA tory o f t r auma , and the pa t i en t is o therwise heal thy. M o d e r a t e l imi tat ion o f left h ip f lexion was present . Conven t i ona l r o e n t g e n o g r a m s d e m o n s t r a t e d a calcif ied o r ossif ied mass pos t e r io r to the head o f the left femur (Fig. 1). A c o m p u t e d t o m o g raph ic (CT) scan (Fig. 2) d e m o n s t ra ted a 5 . 5 x 3 . 0 c m i r regular , a m o r p h o u s , dense mass ar is ing f rom the do r sa l aspect o f the pos t e r io r colu m n o f the left a c e t a b u l u m ; the mass was b r o a d b a s e d and wi thou t a defini te assoc ia ted soft t issue mass. A 99m-Tc me thy lene d i p h o s p h o n a t e bone scan d e m o n s t r a t e d increased up t ake in the left pos t e r io r ace tabular region. CT o f the chest was no r mal . A n incis ional b iopsy and subsequent excis ion o f the lesion were performed.

ヒト仙腸関節の応力および動きに関する研究

Biomechanical experiments were performed on sacroiliac joints of the cadaver pelvis in three different positions to determine changes in stress pattern. The infrared stress analyzing method was used. In the neutral position, principal stress was observed in the middle to upper part of the sacrum, adjacent to the sacroiliac joints, in the central area of the ilium, and in the acetabular region. In the anterior tilting position, the stress on the sacroiliac joints was smaller than in the posterior tilting position, while it was greater in the symphysis pubis area. Further experiments with dial gauges were performed to measure load-displacement value in four cadaver pelves. Vertical loads of up to 100 kg were applied to the fourth lumbar vertebra. At the maximum test loads, displacement of the anterior surface of the first sacral vertebra ranged from 0.18 mm to 0.73 mm in the anterior direction. In conclusion, it is clear that the range of movement in the sacroiliac joints is very small and that this joint plays a significant role in the maintenance of stability in the pelvic girdle.

成人に発症したＨａｎｄ‐Ｓｃｈｕｅｌｌｅｒ‐Ｃｈｒｉｓｔｉａｎ病の１例

Hand-Schuller-Christian Disease is usually diagnosed in children and young adults. An unusual case of Hand-schuller-Christian disease with severe pulmonary involvement in a middle aged man was reported. A 48 years old man complaining of gait disturbance came to our clinic in June 1988. He had noticed polydipsia and polyuria since 1980, but worked as a taxi driver. He had noticed the onset of pain in both knees in Oct. 1986 and subsequently became incapaciated and was able to move only with assistance. Roentgenograms showed symmetrical sclerosis involving metaphysis and diaphysis of the proximal ulna, proximal humerus and distal femur. There were osteolytic lesion in the sclerotic area in the proximal tibia, femur and acetabular region of the left pelvis and pathologic supracondylar fracture of the both femurs.He voiced 10 liters of urine with a specific gravity less than 1.002. Open biopsy of the tibia revealed numerous foamy histiocytes in a fibrotic bed.The patient is under the treatment with Prednisolone, Desmo pressin and training with cruch gait.

Results of Total Hip Reconstruction Using Acetabular Mesh in Patients With Central Acetabular Deficiency

Fifty-three patients (54 hips) treated with cemented total hip reconstruction with the aid of an acetabular mesh made of Vitallium (Howmedica Inc., Rutherford, New Jersey), a cobalt-chrome molybdenum alloy, to reinforce the medial cement for deficient bone stock in the central acetabular region, were evaluated at an average follow-up period of 6.8 years (range, five to ten years). Thirty of these patients (30 hips) were treated with revision operations for either failed cup arthroplasty (ten hips), failed endoprosthesis (six hips), or failed total hip arthroplasty (14 hips) and presented difficult problems for acetabular reconstructions. Although none of the hips required reoperations for acetabular loosening, three patients showed roentgenographic evidence of acetabular component migration, and three others showed signs of impending failure of fixation of the acetabular component. The overall mean Harris hip rating improved from a mean of 43 points preoperatively to 87 points at follow-up evaluations. The extent of bone loss in the central acetabular region had the greatest influence on the results of acetabular fixation at the follow-up evaluation. None of the hips with intact medial acetabular cortex had roentgenographic evidence of failure of fixation, while 14% of the hips with medial cortical defects measuring less than 1 cm, and 75% of the hips with larger defects developed acetabular component loosening. The results of total hip reconstruction using acetabular mesh were unsatisfactory in patients with moderate or severe central acetabular bone loss and defects through the medial wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Contact finite element stress analysis of the hip joint and acetabular region

The intraarticular contact areas and pressures across the normal human hip joint (1, 3, 8,11,12, 21) and the stress distributions and around the acetabulum (9, 10, 16, 17, 22) have been investigated experimentally and analytically by many researchers. The present analytical study emphasizes the acetabular side. Brown et al. (2) were the only researchers to conduct contact finite element stress analyses for study of stresses and contact pressures and areas in the hip joint. They conducted two-dimensional plane strain finite element contact stress analyses were conducted of the acetabulum and proximal femur, with emphasis on the femoral side.