A series of 246 patients with scoliosis and attempted fusion had exploration performed six months later in order to detect and treat any pseudarthrosis at an early stage and so prevent subsequent loss of correction. Bilateral or unilateral pseudarthroses occurred in 25 per cent and were of three types--definite, hairline and doubtful. Single unilateral pseudarthroses accounted for 6 per cent and were of little if any clinical significance. The hairline pseudarthroses could not be seen radiologically and were easily missed at exploration. In general the pseudarthroses were least common in the more rigid parts of the spine and in curves which by nature of their aetiology or long duration had become most rigid. Neither the initial severity of the curve nor the degree of correction obtained before the initial attempted fusion had any apparent effect on the incidence. Follow-up for an average of four years has shown that a pseudarthrosis is of little significance with regard to the ultimate result provided it is recognised early and repaired

1. A three-year survey of avascular necrosis of bone has been carried out in a community of some 400 professional divers for shell-fish who had used no modern technique of decompression. 2. Of 301 divers radiographed, 152 (50·5 per cent) had bone lesions. 3. The incidence of bone necrosis increased in proportion to the length of diving experience, being highest in men with over ten years, experience. 4. The incidence was also higher in men who usually dived deeper than thirty metres. 5. There was a high incidence in men with a history of the bends but no significant relationship between the sites of the bends and those of the lesions. 6. Bone lesions were more frequently multiple than solitary. 7. The upper end of the humerus was significantly more affected than the upper end of the femur or tibia, but not significantly more than the lower end of the femur. 8. At the upper ends of the humerus and femur the lesions were more frequently unilateral than bilateral

We assessed carpal collapse by measuring the capitate-radius (CR) distance on standard plain radiographs. This new method required validation of diagnostic accuracy, so we compared it with the method of Nattrass et al. 1. known as revised carpal height (RCH). We studied wrist radiographs from 16 normal subjects and 11 patients with unilateral Kienböck’s disease. We found that there was a significant difference in the left/right CR index between the normal wrists and those with Kienböck’s disease (p < 0.001). The use of left/right RCH index showed no significant difference (p = 0.30). Diagnostic accuracy was shown to be higher for the CR index using ROC curves. We then assessed 40 normal wrists and found the mean CR index to be 0.999 ± 0.034, and suggest that values less than 0.92 are abnormal. The CR index can be used for diagnosis in unilateral carpal collapse, and for monitoring progress where the condition is bilateral

We designed an in vivo study to determine if the superimposition of a microtexture on the surface of sintered titanium beads affected the extent of bone ingrowth. Cylindrical titanium intramedullary implants were coated with titanium beads to form a porous finish using commercial sintering techniques. A control group of implants was left in the as-sintered condition. The test group was etched in a boiling acidic solution to create an irregular surface over the entire porous coating. Six experimental dogs underwent simultaneous bilateral femoral intramedullary implantation of a control implant and an acid etched implant. At 12 weeks, the implants were harvested in situ and the femora processed for undecalcified, histological examination. Eight transverse serial sections for each implant were analysed by backscattered electron microscopy and the extent of bone ingrowth was quantified by computer-aided image analysis. The extent of bone ingrowth into the control implants was 15.8% while the extent of bone ingrowth into the etched implants was 25.3%, a difference of 60% that was statistically significant. These results are consistent with other research that documents the positive effect of microtextured surfaces on bone formation at an implant surface. The acid etching process developed for this study represents a simple method for enhancing the potential of commonly available porous coatings for biological fixation

We present the results of 525 primary Souter elbow arthroplasties undertaken in 406 patients between 1982 and 1997. There were 372 women and 34 men with a mean age of 57 years; 119 patients had a bilateral procedure. The elbows were affected by chronic inflammatory disease, usually rheumatoid arthritis, which had been present for a mean of 24.7 years (2 to 70). In about 30% the joints were grossly destroyed with significant loss of bone. In 179 elbows the ulnar components were metal-backed and retentive; in the remaining 346, with better bone stock, non-retentive, all-polyethylene prostheses were used. Because of complications, 108 further operations were required in 82 patients. During the early years the incidence of complications was higher. Dislocation was the indication for 30 further procedures in 26 patients. Thirty patients underwent 33 revision procedures for aseptic loosening, 12 had 29 operations because of deep infection, two for superficial infection, and 14 further operations were done for other reasons. The cumulative rate of success, without aseptic loosening, five and ten years after surgery, was 96% and 85%, respectively

Objectives

Bioresorbable orthopaedic devices with calcium phosphate (CaP) fillers are commercially available on the assumption that increased calcium (Ca) locally drives new bone formation, but the clinical benefits are unknown. Electron beam (EB) irradiation of polymer devices has been shown to enhance the release of Ca. The aims of this study were to: 1) establish the biological safety of EB surface-modified bioresorbable devices; 2) test the release kinetics of CaP from a polymer device; and 3) establish any subsequent beneficial effects on bone repair in vivo.

Long-term regular haemodialysis for chronic renal failure is associated with amyloidosis. In this condition excess amounts of the unexcretable plasma protein beta-microglobulin are laid down in tendons, joints and bones. Amyloidosis presents with various musculoskeletal disorders only after several years of dialysis. We reviewed 83 patients who had been dialysed for at least 10 years. The commonest complaint was severe joint pain in the absence of radiological changes of arthritis (41%), the shoulders usually being the most affected (33%). Carpal tunnel syndrome had developed in 26 patients, and was bilateral in 14 of them; at operation the presence of amyloid was confirmed. Six of these patients had recurrent symptoms after a further two to three years and required another decompression. Other manifestations of amyloidosis included trigger finger, flexor tendon contracture, spontaneous tendon rupture and pathological fracture through amyloid bone cysts. The frequency of symptoms was proportional to the duration of dialysis: all 13 patients on dialysis for over 20 years were affected. Symptoms developed earlier in older patients

The parameters of cellular proliferation and growth in the growth plates of immature rats were measured after unilateral tibial osteotomy and used to calculate growth rates. Distal osteotomy of one tibia was followed by a bilateral increase in the calculated growth rate of the distal growth plates. However, the ipsilateral distal growth plate grew faster than the contralateral between 12 and 18 days after operation, which appeared to be related to increased cell proliferation and height. Proximal osteotomy led to an increase in growth rates proximally which was more marked on the contralateral side. The lesser response of the ipsilateral growth plate may have been due to local impairment of blood supply, or to greater local release of metabolites after bony damage. Distal tibial osteotomy gave similar results to circumferential release of the distal tibial periosteum. Proximal osteotomy, however, produced a relative impairment of growth on the operated side. This may be of importance in the correction of childhood deformities associated with inequality of leg length

1 . Standard lumbar laminectomy was performed at multiple levels in thirty dogs, and manipulations were carried out in the spinal canal to observe their effects on periradicular adhesion formation. The canal was scarified, packed with Gelfoam, or treated with three varieties of Silastic membranes. The results were serially assessed from three days to twelve weeks by gross observation, nerve conduction studies, histological examination of transverse sections of the spine, myelin study of lumbar roots and micropaque study of the arterial supply to the roots. 2. The results were consistent biologically. The principal source of scar is dorsally in the fibrous tissue elements of the erector spinae muscle mass. This scar, the laminectomy membrane, covers the laminectomy defect and extends into the canal bilaterally to adhere to the dura and nerve roots. 3. Gelfoam does not contribute to scar formation, but instead acts as an effective interposing membrane. Silastic membranes are capable of providing protection against nerve root adhesions without interfering with the anatomical or physiological integrity of the nerves. 4. Certain clinical implications of the study are discussed

1. An analysis has been made of the clinical features and investigations in ninety-five cases of primary intraspinal tumours. 2. Loss of muscle power was the commonest symptom, and was often ignored until late in the course of the disease. 3. Two-thirds of the patients had no pain in the spinal region, although five of these had either extensive growths or radiographical evidence of bone erosion by tumour. 4. One-third of the patients had urinary symptoms, and two of them had acute retention initially attributed to prostatic obstruction. 5. In eighteen cases posture and gait were abnormal. The case histories of five of these patients are recorded, and they emphasise the importance of recognising lumbar spasm and hamstring tightness in young patients as signs of a cauda equina neoplasm. 6. All patients had some detectable sensory, motor, or reflex changes, and these were mostly bilateral. 7. Radiography, and cerebrospinal fluid manometry and analysis, were helpful in establishing the diagnosis. 8. Hysteria should not be diagnosed until all efforts have been made to prove otherwise

Aims

The aims of this study were to characterize antibiotic choices for perioperative total knee arthroplasty (TKA) and total hip arthroplasty (THA) prophylaxis, assess antibiotic allergy testing efficacy, and determine rates of prosthetic joint infection (PJI) based on perioperative antibiotic regimen.

An episode of hypotension is common during cemented joint replacement, and has been associated with circulatory collapse and sudden death. We studied the mechanism of hypotension in two groups of six dogs after simulated bilateral cemented arthroplasty. In one group, with no lavage, the insertion of cement and prosthesis was followed by severe hypotension, elevated pulmonary artery pressure, decreased systemic vascular resistance and a 21% reduction in cardiac output. In the other group, pulsatile intramedullary lavage was performed before the simulated arthroplasties. Hypotension was less, and although systemic vascular resistance decreased, the cardiac output did not change. The severity of the hypotension, the decrease in cardiac output and an increase in prostaglandin metabolites were related to the magnitude of pulmonary fat embolism. Pulsatile lavage prevents much of this fat embolism, and hence the decrease in cardiac output. The relatively mild hypotension after lavage was secondary to transient vasodilation, which may accentuate the hypotension caused by the decreased cardiac output due to a large embolic fat load. We make recommendations for the prevention and management of hypotension during cemented arthroplasty

Aims

The aim of this study was to analyze the effect of a lateral rim mesh on the survival of primary total hip arthroplasty (THA) in young patients, aged 50 years or younger.

Over the 10-year period 1969 to 1978, 271 consecutive cases of congenital dislocation of the hip were diagnosed at birth. Standard anteroposterior radiographs of the pelvis were obtained routinely and were analysed retrospectively. The medial gap, a measure of the separation between the proximal femur and the pelvic wall, was found to be significantly increased in cases with unilateral or bilateral dislocation when compared to normal. A medial greater than five millimetres is indicative of femoral head displacement and is of value where the clinical diagnosis is uncertain. The rate of missed dislocation at birth was 0.6 cases per thousand. Treatment with the Malmo splint was the normal routine. The Pavlik harness was applied if splintage was poorly tolerated by the infant, or in the rare instance of limited hip abduction. Failure to maintain reduction by splintage occurred in 3.3 per cent. The incidence of pressure deformities of the femoral head was 2.95 per cent and there was a residual deformity in later childhood of 1.1 per cent. It is presumed that this lesion can be attributed to the effect of splintage and it was notably avoided in the later period of the review when greater mobility of the abducted hips was encouraged

I have tried to describe the functional attainments of amputees using conventional prostheses. I have outlined the work we have been doing on pneumatic arms for infants and children. I have discussed some of the practical problems in applying pneumatic and myo-electric systems to adults. The inescapable conclusion that one must reach is that two basic clinical requirements must be met before really significant advance is made in this field. Firstly, we must find a method of providing sensory information from the prosthesis. Secondly, we must find a way of utilising more control sites. So far we have only been able to make use of direct movements or myo-electric signals. In the high level bilateral subjects more controls are required than appear to be available. Capener has suggested, in more than one discussion that I can recall, the possibility of using the voice and I have no doubt that a subject could be trained to reserve certain frequencies for prosthetic controls. It may be that we will have to think along some such lines as this

Arthroplasty, with normal or nearly normal reposition, is possible in most old congenital dislocations of the hip in young adults. Reposition is possible even in very high dislocation, but it is difficult or impossible in aged patients and when arthritic changes have taken place. The reduction equalises the length of the extremities in unilateral cases, but makes operation on both sides necessary in bilateral cases. Post-operative complications may be largely avoided by a good technique and careful post-operative treatment. Stability is good, and consequently the limp is generally reduced. Mobility is as a rule sufficient, though often less than before operation when the hip was normally or excessively mobile. Pain is very often relieved or greatly reduced, but walking is generally limited. Even if the radiographic appearance of the hip is almost normal, the functional result may be imperfect. This assessment is probably pessimistic, for two reasons: first, patients operated on are still improving; second, the improved technique of the later operations should give better results. Nevertheless, arthroplasty with reduction should be proposed to patients only suffering severe functional disability

Aims

With an ageing population of patients who are infected with hepatitis C virus (HCV), the demand for total knee arthroplasty (TKA) in this high-risk group continues to grow. It has previously been shown that HCV infection predisposes to poor outcomes following TKA. However, there is little information about the outcome of TKA in patients with HCV who have been treated successfully. The purpose of this study was to compare the outcomes of TKA in untreated HCV patients and those with HCV who have been successfully treated and have a serologically confirmed remission.

Of 1197 renal transplant recipients on the Oxford Transplant Programme, 25 (2%) needed arthroplasties for painful osteonecrosis of the hip. Nine of them had bilateral operations, giving a total of 34 primary total hip replacements (THR). The mean time from onset of symptoms to THR was 2.4 years and from transplantation to THR 5.1 years. The mean follow-up was 5.1 (1 to 14) years. THR relieved the pain in all the patients, but survival analysis indicated a lower survival rate than is usual for primary THR. There were eight major complications. One graft-related problem, early acute tubular necrosis, resolved rapidly after immediate treatment. One patient developed deep infection at 3.5 years after THR which settled with conservative treatment. Five hips developed aseptic loosening requiring revision arthroplasty at a mean of 8.8 years' follow-up. One patient had a non-fatal pulmonary embolism. THR is the treatment of choice for patients with painful osteonecrosis of the hip after renal transplant, but has higher rates of both early and late complications. Surgery should be performed in close association with a renal transplant unit

We inserted two hydroxyapatite (HA)-coated implants with crystallinities of either 50% (HA-50%) or 75% (HA-75%) bilaterally into the medial femoral condyles of the knees of 16 dogs. The implants were allocated to two groups with implantation periods of 16 and 32 weeks. They were weight-bearing and subjected to controlled micromovement of 250 μm during each gait cycle. After 16 weeks, mechanical fixation of the HA-50% implants was increased threefold as compared with the HA-75% implants. After 32 weeks there was no difference between HA-50% and HA-75%. Fixation of HA-75% increased from 16 to 32 weeks whereas that of HA-50% was unchanged. HA-50% implants had 100% more bone ingrowth than HA-75% implants after 16 weeks. More HA coating was removed on HA-50% implants compared with HA-75% implants after both 16 and 32 weeks. No further loss of the HA coating was shown from 16 to 32 weeks. Our study suggests that the crystallinity of the HA coating is an important factor in its bioactivity and resorption during weight-bearing conditions. Our findings suggest two phases of coating resorption, an initial rapid loss, followed by a slow loss. Resorbed HA coating was partly replaced by bone ingrowth, suggesting that implant fixation will be durable