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PubMed1992

Prognosis in Perthes' disease after noncontainment treatment. 106 hips followed for 28-47 years.

The results in 96 patients (106 hips) with Perthes' disease who had had conservative noncontainment treatment were studied after 35 (28-47) years. At skeletal maturity, the radiographic result was poor in 65 hips. At the average age of 43 years, radiographic signs of arthrosis were found in 48 patients (51 hips); 5 patients had had hip replacement and 13 patients had symptoms justifying that procedure. At early phases of the disease, radiographs showed biocompartmentalization of the acetabulum in 24 percent of the hips, but the acetabulum normalized in the majority. There was no difference in long-term prognosis between Catterall's Groups III and IV; two or more signs of head-at-risk were not of prognostic value. The patients' age at diagnosis and the shape of the femoral head at skeletal maturity were the most reliable prognostic factors.

Age Factors↗
PubMed1993

The mechanical cause of congenital dislocation of the hip joint. Dynamic ultrasound study of 5 cases.

5 hip joints with untreated congenital dislocation of the hip were examined for hip movement by ultrasound. With the hip joint flexed, the direction of the dislocated femoral head was posterior to the acetabulum. The dislocated femoral head displaced more posteriorly when the knee joint was extended, with the hip joint held in flexed position. As the dislocated hip was extended, on the other hand, the direction of the dislocated femoral head was anterior to the acetabulum. The dislocated femoral head displaced more anteriorly when the baby tried to bend the hip with the joint held in extended position. These findings indicate that a fetal posture with the hip flexed and the knee extended predisposes to the development of CDH by the action of hamstrings, and that an infant posture with the hip extended is likely to provoke femoral head dislocation by the action of the iliopsoas.

Biomechanical Phenomena↗
PubMed1995

Early revision among 12,179 hip prostheses. A comparison of 10 different brands reported to the Norwegian Arthroplasty Register, 1987-1993.

On the basis of data from the Norwegian Arthroplasty Register during the period 1987-1993, we have compared times to revision for 10 different cemented total hip prostheses. A total of 11,169 patients, with 12,179 primary total hip replacements (THRs), performed with high viscosity cement for primary arthrosis and followed for a maximum of 6.4 years, were included in this study. The Kaplan-Meier estimate of the overall percentage revised after 5 years was 2.5 (95% Confidence Interval: 2.1-3.0). For the Charnley prosthesis (n 6,694), 2.9% were revised after 5 years (95% CI: 2.3-3.4). Using Cox regression to adjust for gender, age, type of cement and use of systemic antibiotic prophylaxis, the Charnley prosthesis was compared with the 9 other brands. The revision rate for the Spectron/ITH combination (Spectron acetabulum, ITH femur) (n 1,034) was only 0.35 (p 0.04) times that of the Charnley prostheses. The Elite/Charnley combination (Elite acetabulum, Charnley femur) (n 507) and the Müller Type prosthesis (n 116) showed poorer results with failure rates 2.3 (p 0.01) and 2.7 times (p 0.04) that of Charnley, respectively. Although the overall results for cemented THRs in general were good, clinically important differences in revision rates were demonstrated among the cemented prosthesis brands. Our findings underline the need for careful evaluation of different total hip replacements.

Hip Prosthesis↗
PubMed1994

Component motion in bipolar hip arthroplasty: an evaluation of reamed and non-reamed acetabula.

Sixty-four patients with 67 bipolar arthroplasties of the hip were reviewed for a mean follow up of 3.1 years. The study group consisted of 46 hemiarthroplasties secondary to primary osteoarthritis of the hip and 21 hemiarthroplasties secondary to displaced subcapital hip fractures. Reaming of the acetabulum was performed in 47 of the hips studied. The Harris hip scores were not significantly affected by acetabular reaming. Total motion decreased when hips were loaded in the standing position. Reaming of the acetabulum resulted in a decrease in percent outer component motion and an increase in percent inner component motion. The non-reamed acetabula had the largest percent inner motion decrease when taken from the supine to the standing position. The reamed acetabula had significantly higher average percentage of inner component motion in both standing and supine positions. There was no patient with postoperative acetabular protrusion.

Aged↗
PubMed2000

Epidemiology, demographics, and natural history of congenital hip disease in adults.

This study examined the epidemiology and demographics of congenital hip disease in 468 (660 hips) patients who were examined between 1970 and 1996. In 356 (54%) hips, the diagnosis was secondary osteoarthritis due to congenital hip disease, and in 272 (41%) hips, the diagnosis was idiopathic osteoarthritis. In the remaining 32 (5%) hips, the diagnosis was uncertain. Of the hips with congenital hip disease, 170 (47.7%) hips were dysplastic, 85 (23.9%) had low dislocation, and 101 (28.4%) high dislocation. The majority of patients with congenital hip disease were women (338 [95%] hips). The natural history of the three types of congenital hip disease was studied in 157 patients (202 hips: 102 dysplastic, 42 low dislocation, and 58 high dislocation) who had received no treatment before the initial examination. Average length of follow-up was 17 years. In dysplastic hips, the disease remained undiagnosed until the onset of symptoms at an average age of 34.5 years. In patients with low dislocation, pain had started at an average of 32.5 years due to progressive degenerative arthritis within the false acetabulum. In patients with high dislocation, in the presence of a false acetabulum, pain started at an average age of 31.2 years, while in its absence, pain started at an average age of 46.4 years due to muscle fatigue. These findings suggest dysplasia, low dislocation, and high dislocation in adults are the results of untreated dysplasia, subluxation, and complete dislocation in infancy, respectively.

Adult↗
PubMed2005

Numerical Investigations of Interactions between the Knee-Thigh-Hip Complex with Vehicle Interior Structures.

Although biomechanical studies on the knee-thigh-hip (KTH) complex have been extensive, interactions between the KTH and various vehicular interior design parameters in frontal automotive crashes for newer models have not been reported in the open literature to the best of our knowledge. A 3D finite element (FE) model of a 50(th) percentile male KTH complex, which includes explicit representations of the iliac wing, acetabulum, pubic rami, sacrum, articular cartilage, femoral head, femoral neck, femoral condyles, patella, and patella tendon, has been developed to simulate injuries such as fracture of the patella, femoral neck, acetabulum, and pubic rami of the KTH complex. Model results compared favorably against regional component test data including a three-point bending test of the femur, axial loading of the isolated knee-patella, axial loading of the KTH complex, axial loading of the femoral head, and lateral loading of the isolated pelvis. The model was further integrated into a Wayne State University upper torso model and validated against data obtained from whole body sled tests. The model was validated against these experimental data over a range of impact speeds, impactor masses and boundary conditions. Using Design Of Experiment (DOE) methods based on Taguchi's approach and the developed FE model of the whole body, including the KTH complex, eight vehicular interior design parameters, namely the load limiter force, seat belt elongation, pretensioner inlet amount, knee-knee bolster distance, knee bolster angle, knee bolster stiffness, toe board angle and impact speed, each with either two or three design levels, were simulated to predict their respective effects on the potential of KTH injury in frontal impacts. Simulation results proposed best design levels for vehicular interior design parameters to reduce the injury potential of the KTH complex due to frontal automotive crashes. This study is limited by the fact that prediction of bony fracture was based on an element elimination method available in the LS-DYNA code. No validation study was conducted to determine if this method is suitable when simulating fractures of biological tissues. More work is still needed to further validate the FE model of the KTH complex to increase its reliability in the assessment of various impact loading conditions associated with vehicular crash scenarios.

Journal Article↗
PubMed1976

[Coxa valga in childhood. Does it need treatment? (author's transl)].

Coxa valga in a child is not necessarily a pathological condition which needs treatment as long as the acetabulum shows adequate development for the patients age and constitution. Varus osteotomy is not indicated in these cases and may even result in poor development of the hip following operation. The author demonstrates a case in which fracture of the femoral neck on one side healed in varus position. Varus osteotomy was subsequently done on the other side to equalize both hips. This resulted in extreme valgus position and narrowing of the joint space of both hips at puberty. The neck-shaft angle of the femur changes constantly during childhool. Valgus position of the femoral neck with good development of the acetabulum occurs frequently and does not lead to secondary osteoarthritis in later life. Prophylactic correction by varus osteotomy should therefore be abandoned unless there is true dysplasia of the hip.

Child↗
PubMed1999

Cementless fixation issues in revision total knee arthroplasty.

Although massive solid allografts can be expected to vascularize and form new bone, variable amounts of replacement as well as collapse and necrosis may be prominent features of these large block allografts. Immunocompatibility seems to be an important factor in allograft healing and incorporation. Large block allograft of the acetabulum appears to be more likely to succeed if autograft is used. Rejection appears to be a significant factor in survival of large allografts. Although bone itself is not highly immunogenic, the role of marrow elements in the cancellous bone graft may be crucial. When possible, marrow contents should be washed carefully from the interstices of cancellous bone to remove cellular elements that do not contribute to osteoinduction but do produce an inflammatory immune response that can compromise healing and bone formation. Washing and soaking the components in antibiotic solution has the additional benefit of making available a reservoir of antibiotic that is released slowly during the postoperative period. Morcellized cancellous bone, rather than finely ground bone which tends to be destroyed by phagocytosis, is the best available choice for reconstructing large volumes of deficient bone stock. Fixation is completely dependent on the existing bone, so that massive defects must be protected until sufficient rigidity develops in the grafted material to allow sharing of weightbearing loads. Clinical experience has shown that migration of the tibial component after reconstruction with morcellized allograft is rare during the first 2 to 5 years after surgery (Fig. 8). These results are surprising in light of reported experience with structural allografts of the acetabulum. Jasty and Harris reported loosening of acetabular components after 4 years in 32% of their cases. The biologic behavior of morcellized allograft differs from that of block allograft, however. Vascularization and ossification are rapid and a permanent, competent loadbearing structure is achieved by filling large deficient areas. The biologic response obtained with the correct technique appears to be early and vigorous. It does not seem likely that progressive collapse would occur after remodeling and healing have been established (Fig. 9). Bone graft handling probably is crucial to the success of grafting of the knee. Antibiotic soaking and washing, removal of bone marrow, and adequate support of the implants are all necessary factors for consistent success of this technique. The results of this salvage procedure have been encouraging. The grafting technique appears to provide long-term support for the implants, so that repeat revision is unlikely.

Adult↗
PubMed1992

Surgical exposure and cement removal in revision total hip arthroplasty.

The surgical approach in revision total hip arthroplasty (THA) must conform to the preoperative goals of revision surgery. Factors to be considered include adequate visualization, assessment of remaining bone stock, presence or absence of cement, status of the trochanter, leg length discrepancies, and previous surgical approaches. To maintain neurovascular structures, blood supply to the involved bone, postoperative abductor function, stability, and gait normalcy, an anterolateral approach is best used. Three anterolateral approaches are used to address various aspects of revision THA. Approach 1 allows for exposure of the acetabulum and proximal femur. The associated abductor muscle split allows for excellent proximal exposure. Approach 2 is performed when acetabular reconstruction is neither complex nor involved, and when extended access to the femur is necessary. The lateral-distal incision is determined by the need for adequate femur exposure for implant removal, cement removal, and any bone grafting procedures to reconstitute osseous structures. Approach 3 is further developed proximally to expose necessary anatomic regions of the acetabulum while preserving the underlying neurovascular structures. Using special instrumentation and controlled femoral perforations, cement mantles are quickly removed, minimizing damage to the bone and preserving the osseous structures. For all three approaches, abductor muscle separation repair and/or reattachment is performed with a heavy, no. 5, nonabsorbable suture. Postoperative patient management depends on the degree of dissection and extent of reconstruction.

Bone Cements↗
PubMed1991

Cup arthroplasty, surface replacement arthroplasty, and femoral head resurfacing for osteonecrosis.

Traditional cup arthroplasty and resurfacing arthroplasty of the femoral head and acetabulum have been proposed as bone-conserving procedures for avascular necrosis of the hip. Resurfacing of only the femoral head is not a definitive procedure but is an alternative to cup arthroplasty and resurfacing arthroplasty of the femoral head and acetabulum; hemiarthroplasty is recommended for the young patient with intact acetabular cartilage. Indications, technique, and clinical results are presented.

Femur Head↗
PubMedDate not supplied

THARIES surface replacements: a review of the first 100 cases.

The first 100 cases of the 135 THARIES surface replacement procedures with 4--32 months follow-up, are evaluated in terms of clinical results, radiographic information and complications. The short but detailed follow-up suggests that this procedure was an excellent alternative for the younger and more active population. The overall hip ratings (pain, walking and function) and range of motion are comparable to that of stem-type total hip replacements. When the THARIES and conventional hip results are further compared in 34 patients matched by sex and age for 3 major etiological groups (osteoarthritis, osteonecrosis and congenital hip dysplasia), the interim results are essentially comparable for both types. Three cases in the first 100 have required revision. One patient (no. 1) with osteoporosis, chondrolysis and arthrofibrosis following slipped capital femoral epiphysis had loose femoral and acetabular components 24 months postoperatively. He was revised to a T-28 hip replacement. The polyethylene socket in another patient (no. 4), the first dysplastic hip in this series, was 20 nm uncovered superiorly, became loose and was revised 9 months postoperatively. Now 15 months postoperative with a more medial THARIES acetabulum, the patient continues to have a good result. Another patient (no. 12) with bilateral dysplastic hips became progressively more disabled due to heterotopic bone, which was then excised 18 months postoperatively. Radiographic studies of the THARIES sockets demonstrate radiolucent zones at the cement-bone interfaces of the acetabulum in 88 cases, partial in 51 and complete in 37. Three hips were currently considered to have evidence of progressive socket loosening but are active and asymptomatic. There have been no femoral neck fractures in this series which we attribute to the custom fitting ability inherent in the range of components, the reaming protocol and the various remodelling guides. There have been no prosthetic breakages, subluxations, dislocations or sepsis. The complications observed in this series are minor and comparable to that of many other total hip arthroplasty operations. Nerve palsy and trochanteric separation have not been major problems although one existing peroneal nerve dysfunction and one trochanteric migration emphasize the need to minimize these complications by careful handling of the operative leg, and an accurate trochanteric reattachment technique.

Adolescent↗
PubMed1998

[Causative ananlysis for redislocation after operative reduction of congenital dislocation of hip].

Redislocation of the femoral head may be occured after its operative reduction in the congenital dislocation of the hip, therefore, it is greatly important to disclose the causes of the redislocation in order to avoid this every complication and improve the curative effect of this operation. Seven cases of redislocation from 106 cases (128 sides) of the congenital dislocation of the hip which had been reduced operatively were studied with relative measurements of the hip joints on roentgenogram, associated their pathologic conditions described in operation. The results showed that, in these cases, there were (0.843 +/- 0.692) cm upward displacement of the femoral head beyond the horizontal Y line, (68.86 +/- 0.692) degree of the femoral anteversion, the more lateral displacement of the femoral head compared to the opposite side and the acetabular index increasing up to (33.86 +/- 3.72) degree from (26.14 +/- 2.73) degree of the operative correction. These phenomena indicate that the redislocation after operative reduction of the femoral head in congenital dislocation of the hip is mainly related to four causes which include the existence of large pressure between acetabulum and femoral head, the uncorrected abnormal femoral anteversion, the residue of the pathologic tissues in the acetabulum and the reascending of the acetabular index having been corrected in operation.

Child↗
PubMed1998

[Analysis of causes of revision after hip replacement].

From 1974 to 1991, two hundred and sixty-four cases of hip replacement were performed. These cases composed of 150 cases of artificial femoral head prosthesis replacement and 114 cases of total hip replacement. Fifteen cases were revised after the first replacement in 7.4 years average (5-16 years). The revision rate was 5.7%. The causes of revision were loose or subside of prosthesis, wear and tear of acetabulum, dislocation of artificial hip joint, etc, which caused pain and dysfunction. The revision cases were followed up for 4.7 years average with good result. To prevent revision, The medully canal shonld not be too wide and in osteoporosis cases, bone cement was suggested to apply. The chondrium of acetabulum should be removed completely.

Aged↗
PubMed2000

[Morpho-metrical features of the pelvis in standing posture].

The morpho-metrical features of the human pelvis differ according to gender, particularly with regard to size and shape, and bipedal standing posture appears to have been a major determinant of pelvic structure. In standing posture, the three points of the right and left superior anterior iliac spines and pubic tubercle are in contact with the vertical frontal plane. In this situation, the superior anterior iliac spine is lower than the superior posterior iliac spine. From a lateral view, the vertical line from the body's center of gravity passes through the center of the hip joint or acetabulum. The anatomical or biomechanical problem has been whether the line of gravity passes through the promontory or the center of auricular surface. To clarify this point, the three points of the acetabular center, promontory and auricular center were examined as to how they are positioned in relation to each other and the distance of each on the vertical frontal plane. Those measurements are as followed: A) distance between vertical frontal plane and promontory, B) distance between vertical frontal plane and anterior margin of auricular surface, C) distance between vertical frontal plane and mid-point of auricular surface computed from (B + D)/2, D) distance between vertical frontal plane and posterior margin of auricular surface, E) distance between vertical frontal plane and mid-point of acetabulum, F) inclination angle of the pelvis. From the results, the acetabular center and promontory are in alignment with the vertical line. The auricular center is positioned further back than the acetabular center or promontory. In this situation, the mean angle of inclination of the pelvis was found to be 63 degrees in 16 Japanese male specimens. The means of the other Japanese populations are into range of 63 degrees to 66 degrees in the males. If the auricular center coincides with the acetabular center, it is possible the angle of inclination of the pelvis would exceed 63 degrees. The frontal plane in contact with the right and left superior anterior iliac spines and pubic tubercle is not vertical. The morphological features clarified in the present study are that the promontory and acetabular center are in vertical alignment when viewed laterally and that the angle of inclination of the pelvis is 63 degrees.

Asian People↗
PubMed2000

Proximal femoral fracture. Range of hip motion as a predictor of fracture type.

A cadaveric study has shown that the femoral neck impinges on the posterior part of the acetabulum at an average of 54.5 degrees external rotation and that an intracapsular fracture can be reproduced by an impact load onto the greater trochanter with the hip in external rotation. A clinical study of hip rotation of the contralateral uninjured hip in 100 patients after proximal femoral fracture was done to compare the degree of external rotation between extracapsular and intracapsular fracture. The mean value for intracapsular fracture was 62.1 degrees and for extracapsular fracture was 48.9 degrees. A retrieval study of the femoral head and neck from patients undergoing hip hemiarthroplasty for intracapsular fracture showed a consistent pattern of fracture with posterior comminution suggesting neck impingement. Previous work has suggested that an intracapsular fracture occurs during a fall when external hip rotation thrusts the femoral neck against the posterior margin of the acetabulum. The current investigation would support this hypothesis and suggests that the natural degree of external hip rotation is a predictor of fracture type.

Aged↗
PubMedDate not supplied

[The morphological variability of the maritae of Phyllodistomum umblae and Phyllodistomum folium (Trematoda: Gorgoderidae) from fish in the Lake Baikal basin].

The host variability of adults of Phyllodistomum umblae and P. folium in fishes of the Baikal region has been studied. The absence of considerable geographical variability of P. umblae in Coregonus lavaretus (Lake Baikal, Lake Storsjön in Sweden) has been shown. The complexes of most stable (the size of acetabulum and eggs, location of acetabulum, ovary and vitelline bodies) and variable (the distance from oral sucker to intestinal bifurcation, distance from intestinal back edge to body end, width of seminal vesicle) features of trematodes of the genus Phyllodistomum have been determined.

Animals↗
PubMed2000

The effect of elastic modulus of the backing material on the fatigue notch factor and stress.

In cemented acetabular cup design it is acknowledged that bone resorption and fatigue fracture of cement may cause the most common problems after total hip replacement. Previous studies have optimized the shape of metal backing (MB) shell used in cemented acetabular components in order to minimize the fatigue notch factor (Kf) in cement, whilst at the same time maximizing Kf in bone at the central part of acetabulum to prevent stress shielding and subsequent bone resorption [1]. The optimal shape was found to be thin at the edges and thick at the dome. The present study describes the effect of changing the elastic modulus of the backing material on Kf and stresses as predicted by the initial shape of the backing shell of (3 mm) thick, and the optimized backing shape of non-uniform thickness in order to find the optimal material for the backing shell. It is recommended to use a backing shell material with elastic modulus equals 70 GPa (which can be readily attained using a fiber reinforced polymer composite). It is shown that such a material will decrease the fatigue notch factor and the stresses in cement at cup edges, at the same time it will increase the stresses and the fatigue notch factor in bone at the central part of acetabulum. Thereby, reducing the possibility of fatigue fracture of cement, whilst at the same time decreasing the stress shielding effect and the resulting bone resorption. The effect of lower bone resorption and lower probability of fatigue fracture of the cement will also reduce the incidence of loosening and premature revision operations.

Aged↗
PubMed1975

[The influence of surgically introduced muscle tension on the function of total hip prostheses (author's transl)].

The functional results of total hip prosthesis are influenced significantly by the tension given to the glutaeus medium muscle at operation. Low tension may result in a limp (positive Trendelenburg sign), high tension may decrease movement. In 206 cases of total hip replacement the Trendelenburg sign (grades from 0-3), the movement (in grades 0-4) and a grade of extension (distance or prosthetic femoral head and plastic acetabulum in cm at maximal extension after resection of the capsule) have been evaluated. In 191 hip joints not operated before the Trendelenburg sign was negativ before operation in only 31%, after operation it was negativ in 73%. The evaluation of the partial correlation coefficient showed a definite relation between Trendelenburg sign and the grade of extension. The higher the extensibility of the hip joint the more pronounced the Trendelenburg sign. In 71% of 191 cases the movement was increased after total hip replacement. With increased extensibility, the movement becomes better. However it is also related to the movement before operation. The optimal muscular tension and movement of the hip joint can be expected at an extension grade of 1.5-2.0 cm (distance between the prosthetic femoral head and the plastic acetabulum at maximal extension during operation).

Aged↗