We treated 120 children between the ages of 12 and 31 months with 137 developmental dislocations of the hip and reviewed them at a mean follow-up of 14 years.

We had used two-directional arthrography of all hips before reduction to evaluate the anterior, superior, and posterior portions of the limbus. Of the 137 hips, 64 had no interposed limbus in the AP view of the arthrogram, but 45 of these had an interposed anterior or posterior portion of the limbus. The hips with good stability and no interposed limbus in either AP or lateral arthrograms had excellent results by closed methods; in the other cases the results were less satisfactory.

Our findings suggest that hips suitable for management by closed reduction can be identified by two-directional arthrography. Hips shown to have an interposed limbus are best managed by open reduction.

We report the six-year results of a prospective, controlled demographic trial of developmental dysplasia of the hip (DDH) treated in the Pavlik harness using ultrasound supervision. Our aim was to assess the value of ultrasound and its role in monitoring reduction in the harness, in terms of progression or failure of reduction at an early state.

From 1988 to 1994, a total of 221 patients with 370 ultrasonographically abnormal hips was treated in the Pavlik harness. This represents a treatment rate for the Southampton district of 5.1 per 1000 live births. Sixteen hips in 12 patients were not reduced in the harness and required surgical treatment; 95.7% were successfully reduced. One case of mild avascular necrosis (0.3%) was identified in those treated by harness alone. Of the 221 patients 87.8% remain under radiological review, with 3.2% of affected hips showing continued, mild acetabular dysplasia.

We conclude that ultrasound monitoring has led to an acceptably low level of intervention, a high reduction rate and minimal iatrogenic complications. The trial is continuing.

We performed MRI on 13 infants after operative reduction for developmental dysplasia of the hip (DDH). Using an axial gradient-echo sequence, MRI accurately depicted the acetabular anatomy and confirmed adequate reduction in 12 patients. The one patient with redislocation after surgery was correctly identified. MRI can be carried out quickly, inexpensively and without risk of radiation and is the investigation of choice to confirm adequate reduction in DDH.

We reviewed 32 children after the treatment of simple bone cysts by intralesional injections of methyl-prednisolone acetate. The age of the child and the activity and size of the cyst did not significantly affect the radiological outcome. The earliest time at which the radiological response could be reliably determined was three months. After a median period of review of five years, four (13%) cysts had healed, 20 (62%) cysts were partially visible but sclerotic, four (12.5%) were still visible but opaque and four (12.5%) were clearly visible. The healed and partially visible but sclerotic cysts were classified as having satisfactory radiological healing. This was observed in 13 of 32 cysts (41%) after the first injection, in eight of 21 (38%) after the second injection, but in relatively few of the remaining cysts after subsequent injections.

A satisfactory symptomatic outcome was achieved in all of the 18 children with humeral cysts and in the one child with a fibular cyst irrespective of the radiological outcome, but only in nine (67%) of the 13 children with femoral or tibial lesions, in whom the cysts were healed or sclerotic. The remaining four children had exertional bone pain and repeated fractures of their femoral or tibial cysts which were incompletely healed with sclerosis in one and opacities in three.

We conclude that the healing response to intralesional corticosteroids is unpredictable and usually incomplete even after multiple injections. The failure rate in weight-bearing bones is too high.

We performed intraoperative arthrography of the knee in 12 children with congenital short femur, Blount’s disease or Ollier’s disease in whom the Ilizarov technique was used for correction of deformity, leg lengthening or both.

In each case, arthrography revealed a joint surface considerably different from that assumed from plain radiographs, and resulted in a change in the placement of our reference wires before application of the frame. This gave significant improvement in the mechanical axis obtained at the time of removal of the frame. The technique is safe, cheap and easy to perform. It is a useful adjunct to the application of the Ilizarov frame when used for complex lengthening and correction of deformity in the leg.

Anteriorly displaced fractures of the wrist can be treated by the Kapandji technique of percutaneous intrafocal pinning with pins inserted through an anterior approach to give good reduction and stabilisation of the fracture. We have modified this technique by placing the pins through a posterior approach which decreases the risks of neurovascular damage.

We have used this method to treat six children with distal radial fractures showing anterior displacement or instability. Good anterior stabilisation was achieved. The pins were removed at an average of eight weeks and the patients were then able to return to full activity.

This simple technique can be used for unstable fractures after the failure of conservative treatment or in bilateral fractures in adolescents.

We have reviewed retrospectively 80 patients who were treated for traumatic fractures of the femur with a Grosse-Kempf nail to assess the incidence and causes of persisting pain in the proximal thigh.

At a mean of 21 months after operation 33 patients had residual pain severe enough to interfere with their lifestyle or mobility. This was in the region of the scar on the greater trochanter in three-quarters of the patients. Only four showed no radiological abnormality. There was nonunion of the fracture in two, Paget’s disease in one, breakage of the nail in two and prominence of the proximal locking screw in five, although we found no correlation between prominence of the nail and pain.

There was a strong relationship between pain and heterotopic ossification at the proximal end of the implant; this was present in 64% of the patients with pain as compared with those without pain (p < 0.001, Mann-Whitney U test). Of the 80 patients, 27 had the implant removed after 18 months, 17 of them because of pain. In six of these 17, the pain was not relieved. Prominence of the nail proximally was not associated with pain, but protuberance of laterally-based proximal locking screws caused problems. We found a strong association between heterotopic bone formation and pain, but it is uncertain whether this is the true cause or merely an indication of some other factor such as traumatic damage to the glutei during insertion of the nail. Removal of the implant does not always cure such pain.

Three middle-aged patients with diabetes sustained fractures of the acetabulum which were treated by open reduction and internal fixation. In each, rapid dissolution of the femoral head occurred with minimal discomfort, typical of a Charcot arthropathy. The patients had no other evidence of neuropathic arthropathy. Charcot changes may occur after high-energy trauma in patients with diabetes.

A 16-year-old boy was involved in an agricultural accident in which he sustained a large wound to the right arm and forearm. Radiological examination showed loss of the distal half of the humerus. A posterior splint was applied and after two months there was regeneration of the distal humerus including the articular portion. He was able to use his arm at five months. Twenty years later, he had a painless elbow and a 70° range of movement.

Stable fixation after a corrective supracondylar osteotomy in adults is difficult because of the irregularity of the area of bony contact, displacement of the fragments, the predominance of cortical bone, and the need for early mobilisation.

We have used the Ilizarov apparatus for fixation in 15 patients who were treated by complex osteotomies with displacement of fragments for cubitus varus or valgus. Most patients with cubitus varus required medial displacement with rotation of the distal fragment. Those with cubitus valgus required lateral shift of the distal fragment to reduce the medial prominence of the elbow that would otherwise result.

All osteotomies united within the expected time without loss of correction, despite early mobilisation. Complications related to the fixation were few and had resolved at the long-term follow-up.

We performed a neurological and radiological study of the wrists of 58 patients with Hansen’s disease and 60 age-matched healthy control subjects. Significant differences (p < 0.01) were found between the groups in the carpal glenoid sector, the radial physeal widening index, the carpal ulnar distance, the carpal index and in distal radio-ulnar discrepancy.

Comparison of the results in three subgroups of leprous patients with sensory impairment (group A-1), motor deficit (A-2) and no neurological impairment (A-3), showed significant differences (p < 0.01) between group A-1 and the other two. This suggests that in these patients the changes in the carpus and radiocarpal joint may be caused by neuropathic arthropathy of the wrist.

Our findings are of particular interest since there are few reports of neuropathic arthropathy in non-weight-bearing joints.

We classified fractures of the base of the middle phalanx into five types: 1) single palmar fragment; 2) single dorsal fragment; 3) two main fragments; 4) not involving the articular surface, including epiphyseal separation in children; and 5) all others. Types 1 and 2 were subclassified into avulsion, split and split-depression.

Surgery is recommended for unstable type-1 avulsion fractures, type-2 avulsions which may develop buttonhole deformities, and all fractures which displace articular cartilage surfaces. Long-term follow-up showed that surgical treatment which produced good stability and congruity gave good results. These should be the primary aims of treatment.

We used magnetic resonance (MR) myelography in ten patients with injuries to the brachial plexus and compared the findings with those obtained by conventional myelography and postmyelographic CT (CTM). In the presence of complete nerve-root avulsion (seven cases), a post-traumatic meningocele was detected by MR myelography. In injuries to the upper roots (three cases) MR myelography showed abnormal findings with a high signal intensity in the nerve root, obliteration of the damaged nerve root, or enlargement and obliteration of the root sleeve. No pseudomeningoceles were detected in these upper-root injuries by MR myelography and CTM. The overall accuracy of detection of damaged nerve roots or root sleeves was better with MR myelography than with conventional myelography and was similar to that of CTM.

MR myelography is non-invasive, relatively quick, requires no contrast medium, provides imaging in multiple projections, and is comparable in diagnostic ability to the more invasive, time-consuming techniques of conventional myelography and CTM.

The short-term assessment of 14 arthroscopic synovectomies of the elbow in 11 patients with rheumatoid arthritis showed that 93% achieved a short-term rating of excellent or good on the Mayo Elbow Performance Score. At the most recent assessment at an average of 42 months, however, only 57% maintained excellent or good results; four had required total elbow replacement.

Although rehabilitation is facilitated by an arthroscopic procedure the results deteriorate more rapidly than after open synovectomy. This may be due to the limitations of the arthroscopic technique and is consistent with experience of the similar procedure in the knee. Recognition of the short-term gain and the potential for serious nerve injury should be considered when offering arthroscopic synovectomy.

We treated 35 patients with primary malignant tumours of the periacetabular area by resection and prosthetic reconstruction of the defect. At a mean follow-up of 84 months, 15 patients (43%) were free from disease. The most common complications were deep infection (26%), local recurrence (24%) and recurrent dislocation of the hip (17%). The surviving patients achieved an average of 70% of their premorbid function.

This method of reconstruction has a high morbidity and should be performed only at specialist centres, but the functional and oncological outcomes are satisfactory.

Chemical prophylaxis is known to reduce the venographic prevalence of deep-vein thrombosis (DVT) after total knee replacement (TKR), but it is uncertain whether this affects the incidence of symptoms. Further analysis depends on the basic epidemiology of thromboembolic symptoms. We therefore studied the pattern of such symptoms in a consecutive series of 1000 patients with primary TKR, with particular reference to risk factors and prophylaxis.

We reviewed all the clinical records and contacted all the patients individually, noting risk factors, prophylaxis, symptomatic pulmonary embolus (PE) or DVT and its timing, death and its causes, and all complications. All the patients wore antiembolism stockings, 83% had regional anaesthesia and 33.9% had chemical prophylaxis.

One patient died from PE on the day of surgery, having had no prophylaxis giving a rate of 0.1% (95% CI 0.003% to 0.56%). Symptomatic, radiologically confirmed thromboembolism (VTE) was common with a rate of 10.6% (95% CI 8.7% to 12.5%). There was a similar incidence of VTE in those with and without chemical prophylaxis (10.1% v 10.5%, RR 0.96, NS). VTE was more common in patients with risk factors (15.1% v 9.5%, RR 1.59, p = 0.02) and tended to occur earlier in this group (median day of onset 5 v 7, p = 0.01). Chemical prophylaxis did not reduce the frequency of symptomatic thromboembolism in either those with risk factors (RR 0.81, p = 0.5) or those without them (RR 0.94, p = 0.8). Haematoma or wound dehiscence was more common in those having chemical prophylaxis (11.9% v 6.9%; RR 1.73 95% CI 1.16 to 2.60). Readmission for symptomatic, radio-logically confirmed thromboembolism involved 1.1% of patients (95% CI 0.55% to 2.1%). Four patients were readmitted with proven non-fatal PE and six with proven DVT (the latest on day 40).

Our results show that the main risk factor for thromboembolism was TKR itself; chemical prophylaxis did not reduce the incidence of symptomatic thromboembolism but gave an increased perception of side-effects. New prophylactic methods or combinations of methods are needed, with their efficacy compared by randomised controlled studies of both the clinical and the radiological effect.

We performed routine venography after operation in a consecutive series of 252 patients with total joint arthroplasties in whom no form of routine chemical or mechanical prophylaxis had been used.

The prevalence of deep-vein thrombosis (DVT) was 32% (16% distal, 16% proximal) after total hip replacement and 66% (50% distal, 16% proximal) after total knee replacement (p < 0.001). We did not treat distal DVT. There were only two readmissions within three months of surgery because of thromboembolic disease. There were two deaths within this period, neither of which was due to pulmonary embolism.

Between 1971 and 1991 we performed Charnley low-friction arthroplasty (LFA) on 116 patients (186 hips) with juvenile chronic arthritis (JCA). We have now carried out a survival study, taking endpoints as revision, death or the end of the year 1993.

Overall survival was 91.9% at ten years and 83.0% at 15 years. That of the femoral component was 95.6% at ten years and 91.9% at 15 years and of the acetabulum 95.0% and 87.8%, respectively. Only the use of steroids significantly impaired the survival.

We therefore recommend the use of Charnley LFA for young patients with JCA requiring total hip replacement.

We investigated 15 patients with painful hip arthroplasties using intra-articular injection of bupivicaine. Fourteen had pain relief and 13 of them were subsequently found to have loosening of one or both components. The relief of pain after total hip arthroplasty by intra-articular injection of bupivicaine indicates that a satisfactory result is probable after revision surgery with refixation of the components.

We diagnosed entrapment of the superficial peroneal nerve in 17 patients (19 legs) with a mean age of 41 years. In all cases, plain radiographs of the leg, nerve-conduction studies of the superficial peroneal nerve and measurement of the intramuscular pressure at rest after exercise were normal. Diagnostic tests for nerve compression during rest after exercise produced pain and clinical signs in all.

We performed decompression of the superficial peroneal tunnel in 14 patients and local fasciectomy in three. Fourteen patients (80%) were free from symptoms or satisfied with the result.

Between 1986 and 1995, we treated with foraminal injection of local anaesthetic and steroids 30 patients with severe lumbar radiculopathy secondary to foraminal and extraforaminal disc herniation which had not resolved with rest and non-steroidal anti-inflammatory agents. They were assessed prospectively using standardised forms as well as the Low Back Outcome Score, and were reviewed at an average of 3.4 years (1 to 10) after injection by an independent observer (BKW).

Relief of symptoms was obtained in 27 immediately after injection. Three subsequently relapsed, requiring operation, and two were lost to long-term follow-up. Thus 22 of the 28 patients available for long-term follow-up had considerable and sustained relief from their symptoms. Before the onset of symptoms 17 were in employment and, after injection, 13 resumed work, all but two in the same job. The average score before injection was 25 out of a possible 75 points. At follow-up, the overall average score was 54, and in those who had obtained relief of symptoms it had improved to a mean of 61.

Based on these findings we recommend foraminal injection of local anaesthetic and steroids as the primary treatment for patients with severe radiculopathy secondary to foraminal or extraforaminal herniation of a lumbar disc.

We describe the successful relief of compression of the spinal cord due to a vertebral haemangioma by transcatheter embolisation using cyanoacrylate compounds before operation, and provide a brief review of the literature.

We report an unusual presentation of a solitary plasma-cell myeloma of the spine in an adolescent patient. Our case indicates the need to consider plasma-cell myeloma as a differential diagnosis even in younger patients.

We evaluated the effects of a serum protein coating on prosthetic infection in 29 adult male rabbits divided into three groups: control, albumin-coated and uncoated. We used 34 grit-blasted, commercially pure titanium implants. Eleven were coated with cross-linked albumin. All the implants were exposed to a suspension of Staphylococcus epidermidis before implantation.

Our findings showed that albumin-coated implants had a much lower infection rate (27%) than the uncoated implants (62%). This may be a useful method of reducing the infection of prostheses.

Transarticular screws at the C1 to C2 level of the cervical spine provide rigid fixation, but there is a danger of injury to a vertebral artery. The risk is related to the technical skill of the surgeon and to variations in local anatomy.

We studied the grooves for the vertebral artery in 50 dry specimens of the second cervical vertebra (C2). They were often asymmetrical, and in 11 specimens one of the grooves was deep enough to reduce the internal height of the lateral mass at the point of fixation to ≤2.1 mm, and the width of the pedicle on the inferior surface of C2 to ≤2 mm. In such specimens, the placement of a transarticular screw would put the vertebral artery at extreme risk, and there is not enough bone to allow adequate fixation.

Before any decision is made concerning the type of fixation to be used at C2 we recommend that a thin CT section be made at the appropriate angle to show both the depth and any asymmetry of the grooves for the vertebral artery.

We developed a rat model of limb lengthening to study the basic mechanism of distraction osteogenesis, using a small monolateral external fixator. In 11-week-old male rats we performed a subperiosteal osteotomy in the midshaft of the femur with distraction at 0.25 mm every 12 hours from seven days after operation.

Radiological and histological examinations showed a growth zone of constant thickness in the middle of the lengthened segment, with formation of new bone at its proximal and distal ends.

Osteogenic cells were arranged longitudinally along the tension vector showing the origin and the fate of individual cells in a single section. Typical endochondral bone formation was prominent in the early stage of distraction, but intramembraneous bone formation became the predominant mechanism of ossification at later stages. We also showed a third mechanism of ossification, ‘transchondroid bone formation’. Chondroid bone, a tissue intermediate between bone and cartilage, was formed directly by chondrocyte-like cells, with transition from fibrous tissue to bone occurring gradually and consecutively without capillary invasion.

In situ hybridisation using digoxigenin-11-UTP-labelled complementary RNAs showed that the chondroid bone cells temporarily expressed type-II collagen mRNA. They did not show the classical morphological characteristics of chondrocytes, but were assumed to be young chondrocytes undergoing further differentiation into bone-forming cells.

We found at least three different modes of ossification during bone lengthening by distraction osteogenesis. We believe that this is the first report of such a rat model, and have shown the validity of in situ hybridisation techniques for the study of the cellular and molecular mechanisms involved in distraction osteogenesis.

We have developed a novel, two-layered, collagen matrix seeded with chondrocytes for repair of articular cartilage. It consists of a dense collagen layer which is in contact with bone and a porous matrix to support the seeded chondrocytes. The matrices were implanted in rabbit femoral trochleas for up to 24 weeks. The control groups received either a matrix without cells or no implant.

The best histological repair was seen with cell-seeded implants. The permeability and glycosaminoglycan content of both implant groups were nearly normal, but were significantly less in tissue from empty defects. The type-II collagen content of the seeded implants was normal. For unseeded implants it was 74.3% of the normal and for empty defects only 20%. The current treatments for articular injury often result in a fibrous repair which deteriorates with time. This bilayer implant allowed sustained hyaline-like repair of articular defects during the entire six-month period of observation.

We examined the cellular responses to various particles injected into the knees and the intramedullary femoral cavities of rats in the presence of polymethyl-methacrylate (PMMA) plugs.

The intra-articular particles were mainly ingested by synovial fibroblasts. Increased numbers of macrophages were not detected and there was only a slight increase in synovial thickness.

Cellular responses in the intramedullary space were similarly mild and bone resorption around the PMMA plug did not occur. Bone formation was inhibited only by polyethylene particles.

In contrast to current views, our study shows that wear particles per se do not initiate bone resorption.

Our aim was to analyse the influence of the size, shape and number of particles on the pathogenesis of osteolysis. We obtained peri-implant tissues from 18 patients having revision surgery for aseptically loosened Freeman total knee replacements (10), Charnley total hip replacements (3) and Imperial College/London Hospital double-cup surface hip replacements (5). The size and shape of the polyethylene particles were characterised using SEM and their concentration was calculated. The results were analysed with reference to the presence of radiological osteolysis.

The concentration of polyethylene particles in 6 areas with osteolysis was significantly higher than that in 12 areas without osteolysis. There were no significant differences between the size and shape of the particles in these two groups.

We conclude that the most critical factor in the pathogenesis of osteolysis is the concentration of polyethylene particles accumulated in the tissue.

Abundant implant-derived biomaterial wear particles are generated in aseptic loosening and are deposited in periprosthetic tissues in which they are phagocytosed by mononuclear and multinucleated macrophage-like cells. It has been stated that the multinucleated cells which contain wear particles are not bone-resorbing osteoclasts. To investigate the validity of this claim we isolated human osteoclasts from giant-cell tumours of bone and rat osteoclasts from long bones. These were cultured on glass coverslips and on cortical bone slices in the presence of particles of latex, PMMA and titanium. Osteoclast phagocytosis of these particle types was shown by light microscopy, energy-dispersive X-ray analysis and SEM. Giant cells containing phagocytosed particles were seen to be associated with the formation of resorption lacunae. Osteoclasts containing particles were also calcitonin-receptor-positive and showed an inhibitory response to calcitonin.

Our findings demonstrate that osteoclasts are capable of phagocytosing particles of a wide range of size, including particles of polymeric and metallic bio-materials found in periprosthetic tissues, and that after particle phagocytosis, they remain fully functional, hormone-responsive, bone-resorbing cells.

We have studied the three-dimensional geometry of the proximal humerus on human cadaver specimens using a digitised measuring device linked to a computer. Our findings demonstrated the variable shape of the proximal humerus as well as its variable dimensions. The articular surface, which is part of a sphere varies individually in its orientation as regards inclination and retroversion, and it has variable medial and posterior offsets.

These variations cannot be accommodated by the designs of most contemporary humeral components. Although good clinical results can be achieved with current modular and non-modular components their relatively fixed geometry prevents truly anatomical restoration in many cases.

To try to restore the original three-dimensional geometry of the proximal humerus, we have developed a new type of humeral component which is modular and adaptable to the individual anatomy. Such adaptability allows correct positioning of the prosthetic head in relation to an individual anatomical neck, after removal of the marginal osteophytes. The design of this third-generation prosthesis respects the four geometrical variations which have been demonstrated in the present study. These are inclination, retroversion, medial offset and posterior offset.