Ischaemia-reperfusion injury (IRI) is caused by endothelial and subendothelial damage by neutrophil-derived oxidants. Vitamin C is an antioxidant which attenuates endothelial injury after IRI. Our aim was to evaluate the effect of oral vitamin C in the prevention of IRI in skeletal muscle. We used a model of cross-clamping (3 hours) and reperfusion (1 hour) of the cremaster muscle in rats. Muscle function was assessed electrophysiologically by electrical field stimulation. Infiltration by neutrophils was determined by the activity of tissue myeloperoxidase (MPO) and tissue oedema by the wet-to-dry ratio. Neutrophil respiratory burst activity was measured in control animals and groups pretreated with vitamin C. IRI significantly decreased muscle function and increased muscle neutrophil MPO activity and muscle oedema. Pretreatment with vitamin C preserved muscle function and reduced tissue oedema and neutrophil infiltration. Neutrophil respiratory burst activity was reduced in the group treated with vitamin C compared with the control group. We conclude that pretreatment with oral vitamin C protects against acute muscle IRI, possibly by attenuating neutrophil respiratory burst activity

We have studied the relationship between movements of the foot and ankle and venous blood flow from the lower limb using colourflow Duplex ultrasound to determine the optimum type of exercise for promoting venous return. Studies of both active and passive movements were carried out on 40 limbs in 20 subjects (18 men; 2 women), with a median age of 27 years (20 to 54). We assessed ankle dorsiflexion and plantar flexion, subtalar inversion and eversion, and a combination of all movements. There was no difference in venous flow when comparing opposite limbs in a single subject (p > 0.5), but active exercises produced higher peak and mean velocities of blood flow than passive ones. The active combined movement produced the highest velocities with an increase of 38% in mean and of 58% in peak flow velocities, which were significantly greater than the peak and mean flow rates produced by passive movements. The active combined exercise would therefore be the most effective in eliminating stasis and could contribute to the prevention of deep-vein thrombosis

We have studied the beneficial effects of a hydroxyapatite (HA) coating on the prevention of the migration of wear debris along the implant-bone interface. We implanted a loaded HA-coated implant and a non-coated grit-blasted titanium alloy (Ti) implant in each distal femoral condyle of eight Labrador dogs. The test implant was surrounded by a gap communicating with the joint space and allowing access of joint fluid to the implant-bone interface. We injected polyethylene (PE) particles into the right knee three weeks after surgery and repeated this weekly for the following five weeks. The left knee received sham injections. The animals were killed eight weeks after surgery. Specimens from the implant-bone interface were examined under plain and polarised light. Only a few particles were found around HA-coated implants, but around Ti implants there was a large amount of particles. HA-coated implants had approximately 35% bone ingrowth, whereas Ti implants had virtually no bone ingrowth and were surrounded by a fibrous membrane. Our findings suggest that HA coating of implants is able to inhibit peri-implant migration of PE particles by creating a seal of tightly-bonded bone on the surface of the implant

Aims

In the absence of an identified organism, single-stage revision is contraindicated in prosthetic joint infection (PJI). However, no studies have examined the use of intra-articular antibiotics in combination with single-stage revision in these cases. In this study, we present the results of single-stage revision using intra-articular antibiotic infusion for treating culture-negative (CN) PJI.

We investigated the effect of calcitonin in the prevention of acute bone loss after a pertrochanteric fracture and its ability to reduce the incidence of further fractures in the same patient. Fifty women aged between 70 and 80 years who had a pertrochanteric fracture of the hip were randomly allocated to group A (200 IU of nasal salmon calcitonin daily for three months) or group B (placebo). Patients in group A showed a significantly higher level of total alkaline phosphatase and osteocalcin on the 15th day after injury and a significantly higher level of bone alkaline phosphatase on the 90th day after surgery. These patients also had significantly lower levels of urinary C-telopeptide (CrossLaps) on the 15th, 45th and 90th days after injury and lower levels of urinary hydroxyproline on the 15th and 45th days after injury. Patients in group A had significantly higher bone mineral density at all recorded sites except the greater trochanter at three months and one year after operation. After a four-year period of clinical observation, five patients (24%) in group B sustained a new fracture, in four of whom (20%) it was of the contralateral hip. Our findings show that calcitonin reduces acute bone loss in patients with pertrochanteric fractures and may prevent the occurrence of new fractures of the contralateral hip in the elderly

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 is to evaluate the clinical results of operative intervention for femoral metastases which were selected based on expected survival and to discuss appropriate surgical strategies.

Aims

To examine the relationship of sex steroid hormones with osteopenia in a nationally representative sample of men in the USA.

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

Aims

Few risk factors for rotator cuff disease (RCD) and corresponding treatment have been firmly established. The aim of this study was to evaluate the relationship between numerous risk factors and the incidence of surgery for RCD in a large cohort.

We report seven cases in which open or closed reduction of a shoulder dislocation associated with a fracture of the humeral neck led to displacement of the neck fracture. Avascular necrosis of the humeral head developed in all six patients with anatomical neck fractures. All five anterior dislocations also had a fracture of the greater tuberosity and both posterior dislocations had a fracture of the lesser tuberosity. The neck fracture had not initially been recognised in three of the seven cases. In five cases attempted shoulder reduction led to complete displacement of the head segment, which was treated by open reduction and minimal internal fixation. In the other two cases, shoulder reduction caused only mild to moderate displacement which was accepted and the fracture was treated conservatively. We conclude that biplane radiography is essential before reduction of a shoulder dislocation. Neck fractures must always be ruled out, especially where there are tuberosity fractures. In our series, careful closed reduction under general anaesthesia with optimal relaxation and fluoroscopic control did not prevent iatrogenic displacement. Prophylactic stabilisation of the neck fracture should be considered before reduction of such a fracture-dislocation. It may be, however, that the prevention of displacement by prophylactic stabilisation does not always prevent late avascular necrosis; we observed this in one case

1. A study of 2,200 patients receiving electro-convulsive therapy showed that fifty-three sustained fractures or dislocations—an incidence of 2·4 per cent. Of the fifty-three injuries, twenty-one occurred in the spine, fifteen in the neck of femur, fifteen in the upper end of humerus, one in the coracoid process; one dislocated jaw required anaesthesia for its reduction (other cases of transient dislocation of the jaw are excluded). 2. The incidence, site, and type of spinal fractures are recorded, and the relation of the fracture to the first convulsion is noted. No late changes were found in the spines of patients examined two years or more after treatment. A neutral position of the spine during the convulsion is believed to diminish the risk of fracture. 3. Fracture of the neck of the femur is a serious injury in these patients. In one case the injury was bilateral. 4. The fifteen cases of fracture-dislocation of the upper humerus are analysed. They included two cases of posterior dislocation of the humeral head; the possible mechanism of this is explained and a method of prevention suggested. 5. Fifty-three patients with chronic epilepsy with psychosis were examined. Four cases of fractured spine were discovered. The site of fracture was different from that of fractures caused by convulsive therapy and a reason for this is suggested. The type and mechanism of the fracture are similar in the two groups

1. The claw position of a finger with intrinsic paralysis is caused by the blocking effect of the transverse lamina on the long extensor. This starts as soon as the metacarpo-phalangeal joint is hyperextended, and increases with further hyperextension. Thus the long extensor loses its pull on the interphalangeal joints and allows them to flex. Therefore, in intrinsic paralysis the claw position can be prevented or cured by keeping the metacarpo-phalangeal joint in flexion, however slight, which can be done by splinting, by tenodesis or by capsulorrhaphy. 2. Replacement of the intrinsics by some active element, although it may improve the action of the fingers, is not necessary for the correction of claw finger. The function of the intrinsics in the prevention of claw finger is not to be found in their extending effect on the interphalangeal joints, but in the flexion effect on the metacarpo-phalangeal joint, or at least in preventing its hyperextension. This is in accordance with the fact that loss of intrinsic function is disastrous only in supple fingers, in which the metacarpo-phalangeal joints tend to assume extreme degrees of hyperextension (Riordan 1953, Brand 1958). In such fingers, the wide range of hyperextension available at the metacarpo-phalangeal joints is, of course, part of a generalised laxity of the soft parts of the fingers. These soft parts generally tend to counteract the tendency to clawing; the less their resistance, the more the human finger as a whole will tend to behave like a musculo-articular model, and such a model without intrinsics will always immediately assume the claw position

1. With the object of perfecting the design of footwear for feet anaesthetic from leprosy, pressures on the soles of feet during walking were measured with transducers sufficiently thin to be worn inside ordinary shoes. 2. It was found that anaesthetic feet without deformity or muscle imbalance did not produce significantly higher pressures than normal feet during barefoot walking on a flat surface. The pressure distribution under drop feet with active posterior tibial muscles differed from normal, with increased pressure under the lateral forefoot and decreased pressures elsewhere. 3. Loss of toes or function of the toes results in high, sharp pressure peaks under the anterior end of the foot during push-off. In deformed feet these pressures are usually concentrated at one or two small areas. 4. In anaesthetic feet the prevention of trophic ulceration largely depends on the even distribution of pressure over the sole of the foot. 5. Moulding by carefully placed arch supports or metatarsal bars effectively redistributes plantar pressure. 6. A shoe with a rigid sole pivoting on a rocker near the centre of the foot most effectively reduces pressures under the forefoot of shortened, deformed feet. 7. We recommend the use of insoles made of microcellular rubber (approximately 1 5 degrees shore). 8. The importance of studying each deformed foot for areas of high pressure before fitting shoes is stressed; a pressure-indicating footprint is satisfactory for this purpose

Aims

The purpose of this study was to determine the functional outcome and implant survivorship of mobile-bearing total ankle arthroplasty (TAA) performed by a single surgeon.