We examined 86 polyethylene inserts, retrieved from total and unicompartmental knee prostheses after an average of 39.5 months in situ, grading them from 0 to 3 for seven modes of polyethylene degradation. Severe wear, with delamination or deformation, was observed in 51% of the implants, and was associated with time in situ, lack of congruency, thin polyethylene, third-body wear debris, and heat-pressed polyethylene. Significant under-surface cold flow was identified in some areas of unsupported polyethylene, and was associated with delamination in the load-bearing areas of thin inserts above screw holes in the underlying metal tray. We recommend the use of thicker polyethylene inserts, particularly in young, active patients and in designs with screw holes in the tibial baseplate. Thin polyethylene inserts which are at risk for accelerated wear and premature failure should be monitored radiographically at annual intervals

The Ilizarov apparatus was used to carry out opening-wedge callotasis of the proximal tibia in ten patients who had suffered premature asymmetrical closure of the proximal tibial physis and subsequent genu recurvatum. In four knees, the genu recurvatum was entirely due to osseous deformity, whereas in six it was associated with capsuloligamentous abnormality. Preoperatively, the angle of recurvatum averaged 19.6° (15 to 26), the angle of tilt of the tibial plateau, 76.6° (62 to 90), and the ipsilateral limb shortening, 2.7 cm (0.5 to 8.7). The average time for correction was 49 days (23 to 85). The average duration of external fixation was 150 days (88 to 210). Three patients suffered complications including patella infera, pin-track infection and transient peroneal nerve palsy. At a mean follow-up of 4.4 years, all patients, except one, had achieved an excellent or good radiological and functional outcome

Angular deformities of the distal radius of 15 sheep were induced by asymmetrical epiphysial distraction. Eleven sheep were between 10 and 20 weeks old; four were older than 24 weeks. Gradual distraction on the medial side of the limb caused partial separation of the epiphysis from the metaphysis, resulting in a valgus deformity. The distraction device was removed three to six weeks after insertion. Spontaneous correction of angulation with growth occurred in the younger sheep; but when the induced valgus angle exceeded 20 degrees correction was poor. In two sheep further distraction was applied on the lateral side and this produced complete correction. Premature closure of epiphyses did not occur after distraction and longitudinal growth of the bone remained normal. In the older sheep asymmetrical distraction succeeded in inducing angulation in only one case, and correction was poor

1. The bad reputation of fractures of the scaphoid bone is based on a) past disasters caused by inadequate splintage and premature resort to operation; and b) selection of disabling cases for publication. 2. The results obtained in five series comprising over 1,000 fractures suggest that 95 per cent of adequately studied fractures less than a month old unite if properly treated. 3. Sixty cases of established non-union have provided evidence that disability is almost always the result of further injury and that the disability is usually relieved by a short time in plaster. 4. There is no evidence to support the widely held beliefs that a) union by bone can occur only if the fracture is immobilised throughout the process; and b) union after prolonged immobilisation is due to the immobilisation. 5. A policy of treating the wrist and not merely its radiological appearances is advocated

Radiographs of 155 Indian children were examined to identify the acetabular changes which occur in Perthes' disease. These changes included osteoporosis of the acetabular roof, irregularity of contour, premature fusion of the triradiate cartilage, hypertrophy of articular cartilage and changes in dimensions. These changes tended to be more marked in older children and when more than half of the femoral epiphysis was involved. Comparison with 25 cases of Perthes' disease from Liverpool showed the same picture. Several of the acetabular changes noted during the active stages were also seen in a series of 24 adult hips after Perthes' disease. Radio-isotope scans of the hips of 27 children with Perthes' disease showed a consistently increased uptake in the acetabulum on the affected side, indicative of a local increase in vascularity and metabolic activity. It was possible to postulate a working model for the pathogenesis of all the acetabular changes. A number of statistical correlations suggest that most of the changes have a bearing on the final outcome

Magnetic resonance imaging (MRI) of the spine produces images which reflect the chemical composition of the intervertebral disc. We have conducted a prospective study of the serial changes in the MRI appearance of the intervertebral disc after chemonucleolysis with the enzyme chymopapain. Fourteen patients were studied after single-level chemonucleolysis and the results compared with a control group of 17 discs in six patients who had diagnostic discography without enzyme insertion. A consistent pattern of gradual loss of signal from the nucleus pulposus culminating in complete loss of nuclear signal was seen in all cases after chemonucleolysis. Chymopapain therefore produced MRI changes analogous with premature gross disc degeneration. The rate at which this occurred varied; complete loss of signal took at least six weeks. Transitory minor end-plate changes were present in five patients, probably representing a mild chemical discitis. No similar changes were seen in the discography group

1. Eighteen normal discs from cadavers and seventy-five specimens of abnormal disc material obtained at laminectomy have been compared. 2. Imbibition pressure, and not osmotic pressure, is the important factor in maintaining hydration of the nucleus, and the comparison has been based on this finding. The terms "free imbibition index" and "effective imbibition index" are suggested as being readily determinable means of expressing the functional efficiency of a nucleus. 3. A reduction in imbibition pressure was a constant feature of the specimens obtained at operation. No evidence was found to support the theory that hyper-hydration or engorgement of the nucleus plays a part in disc protrusion. A reduction in imbibition pressure can, however, be expected in itself, by a combination of mechanical and hydrostatic effects, to cause disc derangements. 4. The reduced imbibition pressure of abnormal discs is related to abnormal loss of, or deterioration in, the protein/polysaccharide of the nucleus. The premature onset of, or some disturbance in, the normal ageing process is a prime cause of mechanical derangement of the disc

We studied the pattern of proximal femoral growth after severe Perthes' disease (Catterall grade III or IV) by retrospective analysis of serial radiographs in 52 hips (46 patients). Our aim was to determine the relationship between proximal femoral growth abnormalities and metaphyseal cysts, epiphyseal extrusion, physeal narrowing, and extensive epiphyseal necrosis. The average follow-up after treatment was 9.8 years (range 4 to 16 years), and 37 of the hips were followed to skeletal maturity. Slowing of proximal femoral growth was common: symmetrical abnormality was seen in 26 hips and asymmetrical abnormality in nine. However, definite premature closure of the proximal femoral physis was seen in only three hips. Abnormality seemed to be due to altered growth velocity rather than to bar formation in most cases. Metaphyseal cysts, epiphyseal extrusion and physeal narrowing during the active stage of the disease, alone or in combination, were found to be neither sensitive nor specific predictors of the subsequent growth pattern

Aims

The Exeter V40 cemented polished tapered stem system has demonstrated excellent long-term outcomes. This paper presents a systematic review of the existing literature and reports on a large case series comparing implant fractures between the Exeter V40 series; 125 mm and conventional length stem systems.

Displaced fractures of the forearm in children are often treated conservatively, but there is a relatively high incidence of redisplacement, malunion and consequent limitation of function. We have performed percutaneous Kirschner (K) wire fixation in 72 such children under the age of 14 years, of which 57 were reviewed for our study. Both the radius and ulna were fractured in 45 (79%), the radius only in eight and the ulna only in four. The mean initial angulation was 19° in the lateral plane and 9° in the anteroposterior plane for the radius and 15° and 9°, respectively, for the ulna. In 42 patients (74%) we performed closed reduction. In the remaining 15 (26%) closed reduction failed and an open reduction, through a minimal approach, was required before K wiring. At a mean follow-up of 20 months all patients had good functional results with an excellent range of movement. Only five had angulation of from 10° to 15° and none had nonunion, premature epiphyseal closure or deep infection. Percutaneous intramedullary K wiring for forearm diaphyseal fracture is a convenient, effective and safe operation, with minimal complications

The clinical features of nine new patients with dysplasia epiphysialis hemimelica are reported, with a long-term follow-up on a further seven patients who were described in the earliest case reports of this disease. Each of these 16 patients had only one leg involved, but 12 had multiple epiphyses affected. The distal femur, distal tibia and talus were the commonest sites and most patients presented with painless swelling or deformity. Wasting of the muscles of the affected leg was a common finding, and was occasionally disproportionate to the degree of disuse. One patient had the unique combination of involvement of the lateral and medial halves of different epiphyses in the same limb and another had unusual metaphysial changes. Diagnosis was often delayed despite typical radiographic appearances. There was no evidence for a genetic component in the aetiology nor was any common environmental factor identified. Treatment by local excision was generally effective for lesions in the vicinity of the knee, but some patients with involvement of the talus required arthrodesis around the ankle. The long-term prognosis appears to be good and so far only two of these patients have developed premature osteoarthritis

In 1957 Somerville and Scott presented their principles of management for the older child with congenital hip dislocation. They advocated preliminary traction followed, in those hips which remained dislocated, by excision of the limbus and subsequent derotation varus osteotomy of the femur. As alternative regimes are advocated it becomes increasingly important to subject each method to detailed long-term review. One hundred and forty-seven hips in 121 patients aged between 12 months and three years and treated by the standard Somerville and Scott regime have been reviewed. The age at review ranged from 16 to 31 years. The recall rate was 91 per cent. Each patient was seen regularly in a special clinic where detailed notes, radiographs and records were available. The results have been assessed clinically and radiographically by modifications of Severin's criteria to enable comparisons to be made with other published series. Attention has been focused on the good and the bad prognostic factors and on the long-term complications. The most worrying feature has been the premature onset of degenerative arthritis even in hips which seemed to have been satisfactorily reduced

Fractures of the hip in children have been associated with a very high rate of serious complications including avascular necrosis (up to 47%) and coxa vara (up to 32%). Over a period of 20 years, we have treated displaced fractures by early anatomical reduction, internal fixation and immobilisation in a spica cast to try to reduce these complications. We have reviewed 18 patients who had a displaced non-pathological fracture of the hip when under 16 years of age. Their mean age at the time of the injury was eight years (2 to 13). They returned for examination and radiography at a mean follow-up of eight years (2 to 17). Each patient had been treated by early (″24 hours) closed or open reduction with internal fixation and 16 had immobilisation in a spica cast. By Delbet’s classification, there was one type-I, eight type-II, eight type-III, and one type-IV fractures. There were no complications in 15 patients. Avascular necrosis occurred in one patient (type-III), nonunion in one (type-II, one of the two patients who did not have a cast) and premature physeal closure in one (type-I). There were no cases of infection or complications as a result of the cast. Our treatment of displaced hip fractures in children by early reduction, internal fixation, and immobilisation in a spica cast gave reduced rates of complications compared with that of large published series in the literature

Aims

The aim of this study was to determine the extent to which patient demographics, clinical presentation, and blood parameters vary in Kingella kingae septic arthritis when compared with those of other organisms, and whether this difference needs to be considered when assessing children in whom a diagnosis of septic arthritis is suspected.

Since this paper was submitted for publication three additional reports have appeared, two of which represent typical examples of the syndrome. Husson and Parkman (1961) reported the case of a female infant dying at the age of four months with chondroectodermal dysplasia, obliteration of the upper labiogingival sulcus, and congenital heart disease. The heart lesions included anomalous pulmonary venous return, single atrium and a persistent left superior vena cava. There was no known consanguinity. In reviewing the cardiac lesions described in chondroectodermal dysplasia they include another case with anomalous pulmonary venous return described by Darling, Rothney and Craig (1957), which also showed chondroectodermal dysplasia and polydactyly, though details of the extracardiac malformations are not given. Nabrady (1961) described a four-year-old Hungarian girl with ectodermal defects involving the teeth and nails but not the hair, polydactyly, distal shortening of the extremities producing dwarfing, and typical radiological appearances of the long bones. There was presumptive evidence of a septal defect of the heart. There was no consanguinity, but the mother was considered to show a "forme fruste" of the condition. A necropsy report by Meitner (1961) of a newly born premature infant with multiple congenital malformations of organs of ectodermal, mesodermal and endodermal origin is of interest because these malformations included extreme polydactyly of hands and feet, absence of nails, chondrodysplasia, and trilocular heart. In many respects, however, the case is atypical of chondroectodermal dysplasia

1. Histochemical studies have been made of the distribution of alkaline phosphatase, glycogen and acid mucopolysaccharides in normal growing bones (mice, rats and men) and also in forty cases of pathological bone processes (neoplastic and dystrophic). 2. The study of normal material confirmed that alkaline phosphatase is plentiful in calcification of cartilage and even more plentiful in bone formation (whether enchondral or direct). 3. It was observed that glycogen increased in the cartilage areas about to be calcified, and that it disappeared in those calcified. It seemed that osteoblasts did not always contain glycogen. 4. In the pathological material (tumours and dystrophic processes) there was great phosphatase activity in the osteogenic areas and also in the cartilage about to be calcified. Whereas glycogen was plentiful in some cases of neoplastic or reactive osteogenesis, it was absent from others. 5. In every area of normal or pathological ossification, the presence of phosphatase seems to be a rule; glycogen is often but not always present. 6. It appears that alkaline phosphatase plays an important role in the formation of the protein matrix of bone, but is not associated with the elaboration of the mucoprotein cartilage matrix. We believe it is premature to draw any definite conclusion on the behaviour and role of the metachromatic substances in the processes of calcification and ossification. The histochemical study of alkaline phosphatase has shown that this is a valuable method in the detection of reactionary or pathological osteogenic processes which in some cases are difficult to demonstrate with the usual histological methods

Aims

The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA).

Aims

Inflammatory response plays a pivotal role in the pathophysiological process of intervertebral disc degeneration (IDD). A20 (also known as tumour necrosis factor alpha-induced protein 3 (TNFAIP3)) is a ubiquitin-editing enzyme that restricts nuclear factor-kappa B (NF-κB) signalling. A20 prevents the occurrence of multiple inflammatory diseases. However, the role of A20 in the initiation of IDD has not been elucidated. The aim of the study was to investigate the effect of A20 in senescence of TNF alpha (TNF-α)-induced nucleus pulposus cells (NPCs).

An attempt has been made to determine the aetiological factors in infantile idiopathic scoliosis from a clinical, genetic and epidemiological survey of 134 infants, ninety-seven of whom developed a curve in the first six months of life. Plagiocephaly was present in all cases; mental retardation occurred in 13 per cent of males with progressive scoliosis; congenital dislocation of the hip occurred in 3.5 per cent of cases and congenital heart disease in 2.5 per cent; and inguinal hernia was found in 7.4 per cent of males. Approximately 3 per cent of parents and 3 per cent of sibs had the same deformity, thirty times the general population frequency for the Edinburgh area. Other positive findings included an excess of breech presentations and of premature, low birthweight males, and a preponderance of curves developing in the winter months. Infants with progressive scoliosis tended to have older mothers and to come from poorer families. Only three children, all with resolving scoliosis, habitually lay prone in early infancy, in marked contrast to North American infants where this posture is usual. The almost complete absence of infantile idiopathic scoliosis in North America is noted and it is thought that the two facts may be related. The aetiology is likely to be multifactorial, with a genetic tendency to the deformity which is either "triggered off" or prevented by external factors

1. The syndrome of osteoporosis is reviewed and its various causes are mentioned. Osteoporosis in youngish patients without any demonstrable cause is referred to as "idiopathic." The scant literature on this condition is reviewed. Its clinical, radiological, biochemical and histological features are considered. 2. A series of thirty-eight cases is analysed, and illustrative case histories are described. The peculiarities of the disease as it is seen in women are discussed, particularly the relationship to pregnancy and lactation, which appear to act as precipitating factors, rather than being primarily causative. 3. The differential diagnosis is discussed. Osteogenesis imperfecta may not always be easy to distinguish; since it is really a "congenital osteoporosis" this is hardly surprising. 4. The following possible etiological factors are propounded (apart from pregnancy): nutritional, occupational, lack of sex hormone, liver dysfunction, loss of protein, diabetes, premature ageing, hypophosphatasia, "alarm reaction," and inheritance. None of them can be incriminated except in the odd case. The relationship between osteoporosis and idiopathic hypercalcuria is mentioned. The only conclusion regarding etiology is that some people are simply more prone to bone loss than are others, and in these a variety of accentuating factors may render the disorder clinically apparent. 5. The treatment of the condition is unsatisfactory, although occasionally a positive calcium balance may be obtained with sex hormones or intravenous infusion of plasma albumin or whole plasma. The general tendency seems to be towards clinical improvement (biologically "stabilisation" rather than improvement), but some patients become permanently crippled