We have reviewed the serial radiographs of 63 hips in 53 children treated by closed reduction for congenital dislocation with a view to finding a radiological measurement which can predict subsequent acetabular development. All had been followed for more than seven years, and at latest review, 34 hips were dysplastic. Failure to obtain concentric reduction or its loss by migration of the femoral head within one year of reduction were the best predictors of persisting acetabular dysplasia and were best quantitated by the h/b ratio (Smith et al. 1968). The acetabular index at reduction or its decrease in the first year were not reliable predictors. Late treatment was less likely to lead to normal acetabular development, but avascular necrosis did not appear to have a significant influence. The average age at which the acetabulum stopped developing was five years, but ranged from 17 months to eight years. The failure of a dysplastic acetabulum to improve in each annual radiograph after closed reduction should lead to consideration of operation on the acetabulum

Fifty-one infants with limited abduction of the hip and acetabular dysplasia were, between 1969 and 1975, treated with abduction-adduction exercises, administered by the parents; no abduction devices were used. In 1983 a follow-up examination was carried out on 41 of these patients. Although at birth these children had characteristics similar to patients with congenital dislocation of the hip, none of their hips dislocated. At birth acetabular measurements showed that half the children had severe dysplasia and the other half slight dysplasia; the difference between the affected and the healthy hips was significant. At follow-up the gait was normal in all the patients. Movements at the hips were symmetrical and within normal limits in all but one patient. The acetabular angle, the centre-edge angle, the shaft-neck angle, the hip ratio, and the size of the femoral head were the same on the previously affected side as on the normal side. Nineteen of the children followed up had preferred lying on one side and dysplasia of the upper hip had developed. The significance of the sleeping position on the development of acetabular dysplasia is discussed

1. Thirty-seven hips with osteoarthritis underwent phlebography before intertrochanteric osteotomy. The results of this study were reported previously. 2. Thirty-two of the hips were studied and have had a clinical, radiological and phlebographic examination about one year after operation. Three of these were excluded because of technical failures. 3. Twenty-four hips had a normal pattern of venous drainage after operation; of these only two had normal patterns before operation and the rest had had many abnormalities of venous drainage. These hips had been completely or considerably relieved of pain at rest and on activity. 4. In the other five hips, although the venous drainage pattern was still abnormal, in only one was there significant deterioration in the venous pattern; in this group there was also some alleviation of rest pain. 5. The findings are discussed in relation to the pathology of osteoarthritis and the possible influences of intertrochanteric osteotomy. 6. The pain produced by the injection of radiopaque material into the femoral head was similar to the rest pain. This finding is discussed in relation to venous obstruction and congestion

1. A family is described of which several members in four generations suffered epiphysial growth disturbances of an unusual kind in the capital epiphyses of the femur, with shortness of stature. 2. This disorder forms one of a group of epiphysial growth disturbances which embraces several recognised disorders, whose effects on the epiphyses vary in severity. They may occur sporadically or they may be inherited as recessive or dominant characters. 3. Differentiation depends on the behaviour of the joint line–in other words, whether the epiphysis starts to show defects through inability to sustain the stress of weight bearing. In the most serious cases the picture is that of Morquio-Brailsford's disease; when the changes are less severe the appearance may be that of bilateral Perthes' disease. Differential diagnosis is no longer possible in later life, because the ultimate condition of the defective femoral heads is the same. Only in the hereditary cases is one able, by studying the capital epiphyses of the hip in childhood, to differentiate between the changes like those of Perthes' disease on the one hand, and micro-epiphysial dysplasia without necrosis on the other

Between January 1988 and January 1991 we performed 100 consecutive cemented total hip replacements using a zirconia head, a titanium alloy stem and a polyethylene cup. We reviewed 78 of these hips in 61 patients in detail at a mean of 5.8 years (1 to 9). Aseptic loosening was seen in 11 hips (14%). Eight needed revision. In total, 37 cups (47.5%) showed radiolucent lines, all at the cement-bone interface, with 18 (23%) involving all the interface. Of the 78 femoral implants, 17 (21.7%) showed radiolucent lines, and two, which had a complete line of more than 1 mm thick, definite endocortical osteolyses. There was also an abnormally high incidence of osteolysis of more than 2 mm at the calcar. Survivorship analysis showed that only 63% were in situ at eight years. These worrying results led us to abandon the use of zirconia heads, since at the same hospital, using the same femoral stem, cement and polyethylene cup, but with alumina femoral heads, the survival rate was 93% at nine years. We discuss the possible reasons for the poor performance of zirconia ceramic

We reviewed 190 children with brucellosis admitted over a 7.8-year period. Seventy of these had articular involvement (36%) and the most common site was the hip (18%). All but one patient had unilateral infection. The hip was the only joint infected in 20 patients (57%). The next most common articular site was the knee. All patients had painful limitation of movement and this was the only articular sign in 28 (80%). Extra-articular signs included fever and hepatosplenomegaly. Brucella infection should be considered in every child from an endemic area who presents with fever and joint symptoms. The insidious onset and a normal or low leucocyte count help the differentiation from acute septic arthritis. Children with hip involvement had a slower response to treatment, longer hospital stays and a higher incidence of complications and relapse than those without. Complications included dislocation (n = 4) and avascular necrosis of the femoral head (n = 1). Treatment by combination chemotherapy for 6 to 12 weeks usually achieves cure and prevents relapse. A multidisciplinary team approach to management is recommended

Aims

The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky IIIA and IIIB defects.

We studied the morphometry of 35 femora from 31 female patients with developmental dysplasia of the hip (DDH) and another 15 from 15 age- and sex-matched control patients using CT and three-dimensional computer reconstruction models. According to the classification of Crowe et al 15 of the dysplastic hips were graded as class I (less than 50% subluxation), ten as class II/III (50% to 100% subluxation) and ten as class IV (more than 100% subluxation). The femora with DDH had 10 to 14° more anteversion than the control group independent of the degree of subluxation of the hip. In even the most mildly dysplastic joints, the femur had a smaller and more anteverted canal than the normal control. With increased subluxation, additional abnormalities were observed in the size and position of the femoral head. Femora from dislocated joints had a short, anteverted neck associated with a smaller, narrower, and straighter canal than femora of classes I and II/III or the normal control group. We suggest that when total hip replacement is performed in the patient with DDH, the femoral prosthesis should be chosen on the basis of the severity of the subluxation and the degree of anteversion of each individual femur

The results are reported of 44 consecutive Chiari innominate osteotomies performed on 39 adult patients aged between 18 and 55 years for symptoms arising from disproportion between the acetabulum and the femoral head. Predisposing causes included congenital dysplasia of the acetabulum, congenital subluxation of the hip, and Perthes' disease. Follow-up averaged 5 years 2 months. Four pre-operative categories of dysplasia and degeneration were recognised. The analysis of the results from each category made possible the recognition of clinical and radiological features likely to provide a satisfactory result. Of 32 cases now considered to have been selected appropriately, 29 (90%) achieved a significant and apparently lasting improvement. In the other 12 cases there were 9 failures--an unacceptable proportion. The features predisposing to these poor results are discussed. The operation is not difficult. It is safe, and is less demanding than the complex alternative "double", "triple" and "dial" osteotomies. In successful cases there is reduction in symptoms and in limp, and improvement of radiological appearances beginning six months after surgery and progressing to a maximum recovery two to three years later

In laboratory tests, the ultra-high molecular weight polyethylene used for the acetabular cups of Charnley hip prostheses has a very low wear rate against steel. In the body radiographic measurements indicate that the polyethylene wears more rapidly. In order to investigate this higher wear rate, the sockets of acetabular cups removed at post-mortem have been examined using optical and electron microscopy. It has been shown that a socket wears predominantly on its superior part and that this is a direct consequence of the orientation of the cup in the body and the direction of loading of the hip. In the worn region the femoral head in effect bores out a new socket for itself, a process which is visible with the naked eye after approximately eight years. Electron microscopy shows that the predominant wear mechanism is adhesion, but after about eight years the appearance of surface cracks suggests that surface fatigue is taking place in addition to this. Laboratory wear tests have shown that pure surface fatigue is not sufficient to account for the high clinical wear rate. Other deformation processes are suggested and discussed with regard to the higher clinical wear rate

The medial displacement osteotomy of Chiari has an established place in the management of older children and adults with severe hip dysplasia. The results claimed for the operation are, however, variable. There have also been reports of sciatic nerve lesions. In this study ten cadavers were operated upon. Chiari osteotomy was performed upon five, and five acted as controls. The hemipelvis was removed from each cadaver; each specimen was deep-frozen and sectioned transversely. The distance of the sciatic nerve from the nearest bony point was measured in each section and the results were recorded graphically. A further radiographic and photographic study was performed to determine whether apparent displacement at the osteotomy might be misleading. The conclusion was drawn that the sciatic nerve is angulated at the osteotomy and further endangered by the risk of bone splintering at the sciatic notch. The radiographic study suggested that some poor clinical results may be explained by a radiological artefact, because there is a tendency for the osteotomy to hinge posteriorly at the sciatic notch opening anteriorly like a book. Radiographs may suggest excellent medial displacement whereas in fact the femoral head is very poorly covered

The purpose of the work described was to find the average pressure on each of several areas of the acetabular cartilage of the cadaver hip under physiological loads. By obtaining load-deflection curves for one chosen area of cartilage, firstly with all the cartilage present and then after the successive removal of other areas, the fractions of the original load carried by the several areas were found, and hence the average pressures on those areas. Seventeen hips (age range twenty. two to eighty-seven years) were examined. Local pressures varied from zero to 3.4 times the average pressure in each hip. The highest pressures in the series (about 4 to 5 megaNewtons per square metre) were on areas of thin fibrocartilage which were identified at the zenith of certain acetabula. The results are too few to establish whether or not the pressure distribution was age-related. The higher pressures found are within the range which in other experiments has led to fatigue failure of femoral head cartilage, and it is suggested that hips in which such pressures exist under loads of three times body weight may be predisposed to osteoarthritis

1. In a previous investigation, approximately 40 per cent of so-called "primary" degenerative disease or osteoarthritis of the hip appeared to have been the result of an abnormal joint mechanism caused by minimal epiphysiolysis in adolescence. Males were affected much more commonly than females. The residual abnormality of this disturbance, recognised radiologically, was termed the "tilt deformity" of the femoral head. 2. Three groups of young adult males, with different athletic backgrounds, have now been examined to assess the incidence of this abnormality and its relationship to athletic regimes. The condition was found to be more common in subjects who had been engaged in more active regimes and was also related statistically to a history of "growing pains". The deformity is compared with the gross disturbance of adolescent epiphysiolysis or slipped epiphysis, which is believed basically to be caused by chronic stress. 3. Degenerative disease of the hip of this type has a geographical and racial distribution corresponding to the degree of interest in and encouragement of competitive athletic activities. Many cases are therefore postulated to be the direct result of a minor and usually asymptomatic disturbance of this type, attributable to excess activity during adolescence

A series of ten infants is reported, seven of whom showed evidence of osteomyelitis of the upper end of the femur; the remaining three did not, but presented with an acute subluxation of the hip in a febrile illness. Four sequelae among the seven more severe cases were: 1) destruction of the capital epiphysis with dislocation at the hip; 2) destruction of the capital epiphysis, the femoral neck remaining in the acetabulum; 3) destruction of the epiphysial plate with the femoral head, remaining in the acetabulum, connected to the femoral neck by a fibrous union; 4) recovery with coxa magna but no other deformity. The streptococcus plays a greater part in this osteomyelitis of infancy than in osteomyelitis of older children, but various other organisms were identified. The organism should be sought by blood culture as well as from the local lesion. Aspiration of the hip, treatment of the hip in abduction and the use of the appropriate antibiotic are recommended. If there is marked swelling and induration, freer release of the pus is strongly advised. Controlled abduction osteotomy plays a useful part in stabilising the femoral neck in the acetabulum or in stabilising the femoral neck beneath the capital epiphysis, but may usefully be preceded by an arthrograph because late ossification of a detached head sometimes occurs

Objectives

The ability to determine human bone stiffness is of clinical relevance in many fields, including bone quality assessment and orthopaedic prosthesis design. Stiffness can be measured using compression testing, an experimental technique commonly used to test bone specimens in vitro. This systematic review aims to determine how best to perform compression testing of human bone.

We investigated the radiographic and clinical course of 31 patients in whom a bulk acetabular allograft had been used during the cementless revision of a total hip replacement. Two patients died and two were lost to follow-up within 24 months, but of the remaining 27 acetabular components, 12 (44%) showed radiographic evidence of instability at a mean of 46 months. Five of these have been revised. In the 12 failures, signs of instability had been noted at an average of 29 months (1 to 60). Failures during the first 24 months were usually due to technical errors, later failures to gradual migration of the cup into the graft. The cups with the greatest amount of their surface supported by grafts were most likely to migrate, but this migration was usually asymptomatic. Screw fixation of the cup, used in 24 cases, appeared to control the mechanism of failure. Femoral head allografts and distal femoral allografts had been used, with failure in 6 of 16, and 6 of 11 respectively; distal femoral allografts were used only for large defects. The insidious course of late cup migration and graft failure necessitates close radiographic follow-up of patients treated with bulk allografts

We examined radiographic polyethylene wear in 233 cemented total hip arthroplasties (201 patients) with either a metal-backed or a non-metal-backed acetabular cup. All patients had identical cemented one-piece titanium femoral stems with a femoral head diameter of 28 mm. The mean linear wear rate was 0.11 mm/yr in metal-backed sockets and 0.08 mm/yr in non-metal-backed sockets (p = 0.0002). The mean volumetric wear rate was 66.2 mm3/yr in the metal-backed sockets and 48.2 mm3/yr in the polyethylene sockets (p = 0.0002). The addition of metal backing to a cemented acetabular cup therefore resulted in a 37% increase in mean polyethylene wear rates which may partially explain the higher failure rate of cemented metal-backed cups. Linear regression analysis also implicated increased follow-up time (log), gross acetabular migration, metal backing and male gender in increasing polyethylene wear. We advocate the use of an all-polyethylene cup in cemented total hip arthroplasty. The increased polyethylene wear must also cause concern about the wear rate of uncemented metal-backed acetabular sockets

Neglected fractures of the femoral neck, common in young adults in underdeveloped countries, may be complicated by nonunion or avascular necrosis (AVN). We treated 52 cases by open reduction, fixation by compression screw and a free fibular graft. The mean delay between injury and operation was 5.1 months. Of 40 fractures assessed at a mean of 58.8 months (24 to 153), 38 were found to be united and two, owing to surgical errors, were not. Seven of eight heads which were avascular before operation revascularised without collapse, while seven others developed AVN after the procedure. At the last follow-up considerable collapse was apparent in five femoral heads, and 11 hips had developed coxa vara. The fibular graft had fractured in four cases. The hip had been penetrated by the screw in six cases and by the graft in three. Hip function was excellent in seven patients, good in 21 and fair in seven. Five patients had poor results. Incorporation of the fibular graft was seen after four years: in many cases the graft had been almost completely resorbed. We recommend this procedure for the treatment of neglected fractures of the neck of the femur in young adults to reduce resorption of the neck, AVN and nonunion

Maquet's line passes from the centre of the femoral head to the centre of the body of the talus. The distance of this line from the centre of the knee on a long-leg radiograph provides the most accurate measure of coronal alignment. Malalignment causes abnormal forces which may lead to loosening after knee replacement. We report a series of 115 Denham knee replacements performed between 1976 and 1981 using the earliest design of components, inserted with intramedullary guide rods. Patients were assessed clinically and long-leg standing radiographs were taken before operation, soon after surgery and up to 12 years later. In two-thirds of the knees (68%) Maquet's line passed through the middle third of the prosthesis on postoperative films and the incidence of subsequent loosening was 3%. When Maquet's line was medial or lateral to this, an error of approximately +/- 3 degrees, the incidence of loosening at a median period of eight years was 24%. This difference is highly significant (p = 0.001). Accurate coronal alignment appears to be an important factor in prevention of loosening. Means of improving the accuracy of alignment and of measuring it on long-leg radiographs are discussed

Objectives

Previous studies have suggested that metal-on-metal (MoM) Pinnacle (DePuy Synthes, Warsaw, Indiana) hip arthroplasties implanted after 2006 exhibit higher failure rates. This was attributed to the production of implants with reduced diametrical clearances between their bearing surfaces, which, it was speculated, were outside manufacturing tolerances. This study aimed to better understand the performance of Pinnacle Systems manufactured before and after this event.