The Alloclassic and Endoplus femoral stems have the same grit-blasted surface and are hot forged from the same titanium alloy. Only the external form of the implants differs slightly. It was our aim to examine the differences in radiographic bone response between the Alloclassic (second generation) and the Endoplus (third generation) femoral stems.

We compared 79 prostheses in 70 matched patients studied over a minimum of two years. Radiolucent lines, adaptive bone remodelling, subsidence, heterotopic bone formation and lysis were recorded in the Gruen zones.

Radiolucencies were mainly found in zones 1 and 7 but to a greater extent in the Endoplus than in the Alloclassic group (p < 0.001 in zone 1, p < 0.05 in zone 7). We found lucent lines in three or more Gruen zones in seven patients all of whom were in the Endoplus group (p < 0.05). Zones 2 and 6 had a significantly higher rate of lucencies in the Endoplus group (p < 0.001). We encountered a combination of proximal lucent lines in zones 1 and 7 with distal hypertrophy of the cortical bone in zones 2, 3, 5 and 6 in eight patients, all from the Endoplus group (p < 0.05). In other patients bone atrophy (stress shielding) in zones 2 and 6 was seen more frequently in the Endoplus than in the Alloclassic group (p < 0.001). In neither group was there radiological evidence of osteolysis. Heterotopic bone formation and subsidence occurred with similar frequency in both groups.

Our study shows that a small change in the form of the femoral implant can result in statistically significant radiological changes in bone remodelling. Whether this will result in clinical compromise is unknown. However, it seems likely that the Endoplus femoral stem will perform differently from the Alloclassic.

Epidural anaesthesia, with and without opiate, is widely used in total hip arthroplasty (THA). It may cause urinary retention, leading to catheterisation, and a subsequent increase in the likelihood of deep infection. We investigated prospectively the rate of urinary catheterisation in patients after THA performed under general anaesthesia, with or without peri-operative fentanyl and bupivacaine opiate epidural anaesthesia.

Of 173 patients, 75 received general anaesthesia alone and 98 both general and epidural management. The post-operative rate of catheterisation was 14.7% in those who received general anaesthesia alone and 13.3% in those who received both.

Our findings suggest that the rate of post-operative urinary catheterisation does not increase when general anaesthesia is supplemented by epidural anaesthesia using fentanyl and bupivicaine.

We describe the clinical and radiological results of 38 total hip replacements (THR) using the JRI Furlong hydroxyapatite-ceramic (HAC)-coated femoral component in patients younger than 50 years. The mean age at the time of operation was 42 years (22 to 49) and the mean length of follow-up was ten years (63 to 170 months). All patients receiving a Furlong HAC THR were entered into the study regardless of the primary pathology including patients who had undergone previous hip surgery.

The mean Harris hip score improved from 44 before operation to 92 at the last postoperative review. After 12 years the cumulative surivival for the stem was 100% (95% confidence interval 89 to 100). No femoral component was revised. Our results show that the Furlong HAC implant gives excellent long-term results in young patients with high demands.

We reviewed retrospectively the outcome of the treatment by impaction grafting of periprosthetic femoral fractures around loose stems in 106 patients with Vancouver type-B2 and type-B3 fractures. Eighty-nine patients had a cemented revision with impaction grafting and a long or short stem. The remaining 17 had cemented revision without impaction grafting.

Fractures treated by impaction grafting and a long stem were more than five times likely to unite than those treated by impaction grafting and a short stem (odds ratio = 5.5, 95% confidence interval (CI) 1.54 to 19.6; p = 0.009). Furthermore, those with impaction grafting and a long stem were significantly more likely to unite than those with a long stem without impaction grafting (odds ratio = 4.07, 95% CI 1.10 to 15.0; p = 0.035).

There was also a trend towards a higher rate of union in those treated by impaction grafting than in those without (odds ratio = 2.69, 95% CI 0.86 to 8.45; p = 0.090).

Impaction grafting is being increasingly widely used for the restoration of femoral bone stock. It can be successfully applied to periprosthetic femoral fractures but a long stem should be used to bypass the distal fracture line.

Varus and valgus joint laxity of the normal living knee in flexion was assessed using MRI. Twenty knees were flexed to 90° and were imaged in neutral and under a varus-valgus stress in an open MRI system. The configuration of the tibiofemoral joint gap was studied in slices which crossed the epicondyles of the femur.

When a varus stress was applied, the lateral joint gap opened by 6.7 ± 1.9 mm (mean ± sd; 2.1 to 9.2) whereas the medial joint gap opened by only by a mean of 2.1 ± 1.1 mm (0.2 to 4.2). These discrepancies indicate that the tibiofemoral flexion gap in the normal knee is not rectangular and that the lateral joint gap is significantly lax. These results may be useful for adequate soft-tissue balancing and bone resection in total knee arthroplasty and reconstruction surgery on ligaments.

The optimal characteristics of pneumatic compression for mechanical prophylaxis of thromboembolism after total knee arthroplasty (TKA) are not known. Our study compared two methods of calf compression, with the hypothesis that the device which provided a larger increase in peak venous velocity would produce a lower rate of thromboembolism. We performed a prospective, randomised study on 423 patients (472 knees). Duplex ultrasonography was carried out by experienced technicians who were blinded to the device used. Overall, 206 patients (232 knees) used a rapid inflation, asymmetrical compression (RIAC) device and 217 (240 knees) a sequential circumferential compression device (SCD).

The rate of venous thromboembolism was 6.9% with the RIAC device compared with 15% for the SCD device (p = 0.007). The incidence of thrombi with unilateral primary TKA was 8.4% for the RIAC compared with 16.8% for the SCD device (p = 0.03). In 47 patients with a bilateral TKA, the incidence of thrombi was 4% for the RIAC compared with 22.7% for the SCD device (p = 0.05 per knee). There was a low rate of mortality and pulmonary embolism when using mechanical prophylaxis for thromboembolism after TKA. Our findings show that the use of rapid inflation, asymmetrical calf compression gave a significantly lower rate of thromboembolism.

We have assessed the long-term results after operative and non-operative treatment of undisplaced and displaced calcaneal fractures.

At a mean of 6.5 years, we reviewed 70 patients with a calcaneal fracture who were divided into four groups: group 1, 18 patients with undisplaced fractures and a normal Böhler’s angle (BA) who had been treated non-operatively; group 2, 23 with intra-articular fractures and a BA < 10° who had been treated non-operatively; group 3, 13 with intra-articular fractures and a BA > 10° who had been treated surgically; and group 4, 16 with intra-articular fractures and a BA < 10° who had been treated surgically.

The results were assessed by a clinical score considering pain, return to work, return to physical activity, change in shoe-wear and the requirement for subtalar arthrodesis.

Patients with undisplaced calcaneal fractures had a good outcome. Those with displaced fractures treated surgically who presented at follow-up with a BA > 10° had a satisfactory functional outcome and those with displaced fractures who had non-operative treatment had a poor outcome. The poorest outcome was consistently seen in patients who were treated operatively without restoration of BA. Open reduction and internal fixation of intra-articular calcaneal fractures can only be expected to benefit those patients in whom nearly anatomical reconstruction is obtained.

In type-II fractures of the odontoid process, the treatment is either conservative in a halo vest or primary surgical stabilisation. Since nonunion, requiring prolonged immobilisation or late surgery, is common in patients treated in a halo vest, the identification of those in whom this treatment is likely to fail is important.

We reviewed the data of 69 patients with acute type-II fractures of the odontoid process treated in a halo vest. The mean follow-up was 12 months. Conservative treatment was successful, resulting in bony union in 32 (46%) patients. Anterior dislocation, gender and age were unrelated to nonunion. However, nonunion did correlate with a fracture gap (> 1 mm), posterior displacement (> 5 mm), delayed start of treatment (> 4 days) and posterior redisplacement (> 2 mm).

We conclude that patients presenting with these risk factors are unlikely to achieve bony union by treatment in a halo vest. They deserve careful attention during the follow-up period and should also be considered as candidates for primary surgical stabilisation.

We have attempted to describe the epidemiology of femoral fractures in children in the West Midlands region of the National Health Service in England. Our source of data was the Regional Hospital Episode Statistics database for the years 1991-2 to 2001-2. Cases were defined as emergency hospital admissions in patients aged under 16 years, with a diagnostic code of femoral fractures in any field, and resident in the West Midlands.

Between 1991-2 and 2001-2, 3272 children aged under 16 years with femoral fractures were admitted to hospital. The crude incidence during this period decreased from 0.33 to 0.22 femoral fractures/1000/year. Those caused by traffic accidents decreased by 43%, and by falls by 29%. The peak age-gender-specific incidence (0.91/1000/year) was in two-year-old boys, and this was 50% higher than in the next highest age-gender group. In the first year of life, the incidence in boys and girls was the same. Thereafter the rate in boys exceeded that in girls, varying from 1.6 times at 11 years to 4.7 times at 14 years. Falls accounted for 49% of the fractures, varying from 77% in one-year-olds to 26% in eight-year-old children. Traffic accidents were responsible for 26% of fractures varying from 55% in ten-year-old to 2% in one-year-old children. Maltreatment was recorded in 1.3% of all cases, and in 8.5% of children under one year. Twice as many fractures were seen in May to August than in January (winter). The rates of fractures were associated with deprivation for all age-gender groups. Fractures of the shaft accounted for 58% of all fractures, varying from 70% in three-year-old to 34% in 13-year-old children.

Our findings show that there has been a decrease in the incidence of femoral fractures during the 1990s and early 2000s. Two-year-old boys had twice the rate than any other single-year age-gender group. More deprived areas had much higher rates which suggests the potential for greater prevention. A relatively low rate of maltreatment was recorded compared with that in some other studies.

Surgical release of the elbow was performed in 27 patients with post-traumatic stiffness at a mean of 14.5 months after the initial injury. The outcome was related to whether there had been heterotopic ossification, which had occurred in 18 elbows and to whether, if there had been a fracture, it had involved the articular surface, which had occurred in 13 elbows. The final range of movement and the ratio of desired gain in each group were compared at a mean follow-up period of 22.5 months (12 to 43).

The arc of movement of the elbow improved in all patients after the operation. The mean final arc was 110° in those with heterotopic ossification and 86° in those without (p = 0.001). The ratios of desired gain were significantly higher in patients with heterotopic ossification (88.2% vs 54.9%; p < 0.001). There was no significant difference in relation to involvement of the articular surface. Careful assessment of the cause of stiffness is important in order to achieve a satisfactory result from surgery for post-traumatic stiffness of the elbow.

We have compared the density of nerve fibres in the synovium in club foot with that of specimens obtained from the synovium of the hip at operations for developmental dysplasia. The study focused on the sensory neuropeptides substance P; calcitonin gene-related peptide; protein gene product 9.5, a general marker for mature peripheral nerve fibres; and growth associated protein 43, a neuronal marker for new or regenerating nerve fibres. In order to establish whether there might be any inherent difference we analysed the density of calcitonin gene-related peptide-positive nerve fibres in the hip and ankle joints in young rats.

Semi-quantitative analysis showed a significant reduction in the number of sensory and mature nerve fibres in the synovium in club foot compared with the control hips. Calcitonin gene-related peptide (CGRP) positive fibres were reduced by 28%, substance P-positive fibres by 36% and protein gene product 9.5-positive fibres by 52% in club foot. The growth associated protein 43-positive fibres also seemed to be less in six samples of club foot. No difference in the density of CGRP-positive nerve fibres was observed in the synovium between ankle and hip joints in rats.

The lack of sensory input may be responsible for the fibrosis and soft-tissue contractures associated with idiopathic club foot.

Torsional deformities of the tibia are common in children, but in the majority both the torsion and the associated disturbance of gait resolve without intervention. There are, however, a significant number of children and adults with neuromuscular disease who present with pathological tibial torsion, which may require surgical correction.

We conducted a prospective study in two centres, to investigate the outcome of supramalleolar derotation osteotomy of the tibia, using internal fixation with the AO-ASIF T plate. A range of outcome variables was collected, prospectively, for 57 patients (91 osteotomies), including thigh foot angle, foot progression angle, post-operative complications and serial radiographs. Correction of thigh foot angle and foot progression angle was satisfactory in all patients. Three major complications were recorded; one aseptic nonunion, one fracture through the osteotomy site after removal of the plate and one distal tibial growth arrest.

We found that supramalleolar derotation osteotomy of the tibia, with AO-ASIF T plate fixation is an effective method for the correction of torsional deformities of the tibia and the associated disturbances of gait in children and adults with neuromuscular disease, with a 5.3% risk of major complications.

We performed a paired study of mature patients with Perthes’ disease to compare the radiological results after treatment between conservatively- and surgically-treated groups. One patient was selected from each group to create the pairs for this study. Each pair was strictly matched for gender, body mass index, age at onset, stage at the first visit, necrotic area and radiological at-risk signs and each was assessed by comparing the values of six radiological measurements.

Eighteen pairs (36 hips) fitted the criteria. The radiological measurements which showed a statistically better result in the surgical groups were Mose’s method, the acetabular-head index and leg-length discrepancy. There were no statistical differences in the slope of the acetabular roof and the articulotrochanteric distance. Four hips in the conservative group were in Stulberg class II, five in class III and nine in class IV. In the surgical group, 13 were in Stulberg class II, four in class III and one in class IV.

We conclude that surgical treatment improved the sphericity of the femoral head and provided greater acetabular cover, but did not reform the acetabular roof.

It was noteworthy that a greater leg-length discrepancy and a smaller articulotrochanteric distance were not seen in the surgical group. Our study suggests that surgical treatment is preferable in patients with severe Perthes’ disease.

This prospective, longitudinal study documents the muscle strength and baseline function of 18 patients undergoing closed femoral shortening for discrepancy in limb length. Patients were studied for two years following surgery. Function was measured by a self-reported questionnaire, timed tests of performance and measurements of muscle strength and power. After two years, the self-reported function and ability to complete timed functional tests had returned to or improved on the pre-operative values. Muscle strength remained slightly below the pre-operative value and was more marked in the quadriceps than the hamstrings. This study suggests that small decreases in muscle strength and power following closed femoral shortening do not adversely affect the patients’ ability to perform everyday activities.

A reversed Delta III total shoulder prosthesis was retrieved post-mortem, eight months after implantation. A significant notch was evident at the inferior pole of the scapular neck which extended beyond the inferior fixation screw. This bone loss was associated with a corresponding, erosive defect of the polyethylene cup. Histological examination revealed a chronic foreign-body reaction in the joint capsule. There were, however, no histological signs of loosening of the glenoid base plate and the stability of the prosthetic articulation was only slightly reduced by the eroded rim of the cup.

We studied factors contributing to the initiation of fracture and failure of a zirconia ceramic femoral head. The materials retrieved during a revision total hip replacement were submitted to either visual, stereomicroscopic and scanning electron microscopy (SEM) or SEM and energy-dispersive x-ray analysis. X-ray diffraction was performed in order to investigate the extent of tetragonal to monoclinic phase transition. Histological examination was performed on the periprosthetic tissues.

The results showed that failure was due to the propagation during clinical use of defects which may have been introduced into the material during the processing of the ceramic, rather than those intrinsic to zirconia. The literature relating to previous failures of zirconia components is reviewed.

We report the case of a 13-year-old obese child presenting with bilateral stable slipped capital femoral epiphyses, which were managed by percutaneous single screw fixation in situ under image intensifier control using arthrography.

We have evaluated in vivo a novel, polymer-based, matrix for tissue engineering of bone. A segmental defect of 15 mm was created in the ulna of New Zealand white rabbits to determine the regenerative properties of a porous polylactide-co-glycolide matrix alone and in combination with autogenous marrow and/or the osteoinductive protein, BMP-7. In this study four implant groups were used: 1) matrix alone; 2) matrix with autogenous marrow; 3) matrix with 20 μg of BMP-7; and 4) matrix with 20 μg of BMP-7 and autogenous marrow.

The results showed that the degree of bone formation was dependent on the properties of the graft material. The osteoconductive sintered matrix structure showed significant formation of bone at the implant-bone interface. The addition of autogenous marrow increased the penetration of new bone further into the central area of the matrix and also increased the degree of revascularisation. The osteoinductive growth factor BMP-7 induced penetration of new bone throughout the entire structure of the implant. The most effective treatment was with the combination of marrow cells and osteoinductive BMP-7.

Osteonecrosis of the femoral head usually affects young individuals and is responsible for up to 12% of total hip arthroplasties. The underlying pathophysiology of the death of the bone cells remains uncertain. We have investigated nitric oxide mediated apoptosis as a potential mechanism and found that steroid- and alcohol-induced osteonecrosis is accompanied by widespread apoptosis of osteoblasts and osteocytes. Certain drugs or their metabolites may have a direct cytotoxic effect on cancellous bone of the femoral head leading to apoptosis rather than purely necrosis.

Fatigue fractures which originate at stress-concentrating voids located at the implant-cement interface are a potential cause of septic loosening of cemented femoral components. Heating of the component to 44°C is known to reduce the porosity of the cement-prosthesis interface.

The temperature of the cement-bone interface was recorded intra-operatively as 32.3°C. A simulated femoral model was devised to study the effect of heating of the component on the implant-cement interface.

Heating of the implant and vacuum mixing have a synergistic effect on the porosity of the implant-cement interface, and heating also reverses the gradients of microhardness in the mantle.

Heating of the implant also reduces porosity at the interface depending on the temperature. A minimum difference in temperature between the implant and the bone of 3°C was required to produce this effect. The optimal difference was 7°C, representing a balance between maximal reduction of porosity and an increased risk of thermal injury. Using contemporary cementing techniques, heating the implant to 40°C is recommended to produce an optimum effect.