1. The technique of compression-arthrodesis of the knee joint is described. 2. Fifteen consecutive cases are reported in which clinical union was detected at the first inspection from twelve days to six weeks after operation. By this method the total period of disability is reduced to three months. 3. Three mechanical factors which might be responsible for this very early clinical union are examined: compression is believed to be the main factor, although fixation is also important. 4. A fallacy is exposed in the use of bone grafts for arthrodesis of the knee; the graft is less osteogenic than the substance of the bones which form the joint, and it provides inefficient internal fixation. 5. A theory is suggested that compression, even in the presence of slight movement, acts by producing a fixed "hinge" without shearing movement; at this point a bridgehead of flexible osteoid tissue is established in which ossification inevitably takes place despite slight bending movement. 6. A second theory is suggested that high compression forces stimulate early union by liberating bone salts at points of maximum pressure through the action of osteoclasts, and that the local excess of bone salts is redeposited under cellular activity within a range of a few millimetres where there is no pressure

We have examined the process of fusion of the intertransverse processes and bone graft in the rabbit by in situ hybridisation and evaluated the spatial and temporal expression of genes encoding pro-α1 (I) collagen (COL1A1), pro-α1 (II) collagen (COL2A1) and pro-α1 (X) collagen (COL10A1). Beginning at two weeks after operation, osteogenesis and chondrogenesis occurred around the transverse process and the grafted bone at the central portion of the area of the fusion mass. Osteoblasts and osteocytes at the newly-formed woven bone expressed COL1A1. At the cartilage, most chondrocytes expressed COL2A1 and some hypertrophic chondrocytes COL10A1. In some regions, co-expression of COL1A1 and COL2A1 was observed. At four weeks, such expressions for COL1A1, COL2A1 and COL10A1 became prominent at the area of the fusion mass. From four to six weeks, bone remodelling progressed from the area of the transverse processes towards the central zone. Osteoblasts lining the trabeculae expressed a strong signal for COL1A1. At the central portion of the area of the fusion mass, endochondral ossification progressed and chondrocytes expressed COL2A1 and COL10A1. Our findings show that the fusion process begins with the synthesis of collagens around the transverse processes and around the grafted bone independently. Various spatial and temporal osteogenic and chondrogenic responses, including intramembranous, endochondral and transchondroid bone formation, progress after bone grafting at the intertransverse processes. Bone formation through cartilage may play an important role in posterolateral spinal fusion

Aims

Reverse shoulder arthroplasty (RSA) reliably improves shoulder pain and function for a variety of indications. However, the safety and efficacy of RSA in elderly patients is largely unknown. The purpose of this study was to report the mortality, morbidity, complications, reoperations, and outcomes of primary RSA in patients aged > 80 years.

We studied the cellular response to physeal distraction in the growth plates of skeletally immature rabbits. We used a new method of labelling and detection of proliferating cells with bromodeoxyuridine (BUdR) and an anti-BUdR antibody. The application of an external fixator but no distraction force produced no changes in the growth plates. After five days of distraction at a maximum force of 20 N, the growth plate became thicker, mainly because of an increase in the number of hypertrophic chondrocytes, but there was no evidence of increased cell proliferation. Recent fractures were seen at the junction of growth plate and metaphysis but the increase in bone length was insignificant. After ten days of distraction at the same maximum force, the chondrocyte columns had become disorganised and cell proliferation was significantly decreased. There was an increase in bone length due to distraction of the fracture gap. In this model, physeal distraction did not stimulate cell proliferation, but actually inhibited it. The apparent increase in growth-plate thickness produced by distraction is not due to increased cell production, but results from inhibition of endochondral ossification and the consequent accumulation of hypertrophic chondrocytes. Any growth after distraction depends on the ability of growth-plate chondrocytes to divide. The decrease in proliferative activity which we found after ten days of distraction suggests the need for caution in the use of such procedures in young children

Aims

The aim of this meta-analysis was to compare the outcome of total elbow arthroplasty (TEA) undertaken for rheumatoid arthritis (RA) with TEA performed for post-traumatic conditions with regard to implant failure, functional outcome, and perioperative complications.

Colchicine is often used in the treatment of diseases such as familial Mediterranean fever (FMF) and gout. We have previously reported that patients with FMF who had colchicine on a daily basis and who had a total hip arthroplasty showed no heterotopic ossification after surgery. The mechanism by which colchicine causes this clinical phenomenon has never been elucidated. We therefore evaluated the effect of various concentrations of colchicine on cell proliferation and mineralisation in tissue culture, using rat and human cells with and without osteogenic potential. Cell proliferation was assessed by direct cell counts and uptake of (. 3. H)thymidine, and mineralisation by measuring the amount of staining by Alizarin Red. Our findings indicate that concentrations of colchicine of up to 3 ng/ml did not affect cell proliferation but inhibition was observed at 10 to 30 ng/ml. Mineralisation decreased to almost 50%, which was the maximum inhibition observed, at concentrations of colchicine of 2.5 ng/ml. These results indicate that colchicine at low concentrations, of up to 3 ng/ml, has the capacity to inhibit selectively bone-like cell mineralisation in culture, without affecting cell proliferation. Further clinical and laboratory studies are necessary to evaluate the effects of colchicine on biological processes involving the proliferation of osteoblasts and tissue mineralisation in vivo, such as the healing of fractures, the formation of heterotopic bone and neoplastic bone growth

1. The methods by which epiphyses receive their blood supply was studied by means of India ink injections in monkeys. Two types were identified depending upon whether the epiphysis was entirely or partly covered by articular cartilage. In the former, nutrient vessels enter the epiphysis by traversing the perichondrium at the periphery of the plate. In the latter they enter the epiphysis by penetrating the cortex at the side of the epiphysis at a point remote from the epiphysial plate. 2. The histological changes after separation of the second type of epiphysis were also studied. After temporary interference with endochondral ossification marked by increased thickness of the epiphysial plate, healing occurred so rapidly that within three weeks it was difficult to determine that the epiphysis had been separated at all. 3. It is concluded that when nutrient vessels enter an epiphysis at a point remote from the epiphysial plate, that epiphysis can be separated without serious disturbance to its blood supply and accordingly without interference with its capacity for growth. As it has been established that an epiphysis which is entirely covered by articular cartilage cannot be separated without destruction of its blood supply and subsequent avascular necrosis (Harris and Hobson 1956), it is concluded that the prognosis of an epiphysial separation is dependent upon the degree of damage to its blood supply rather than the mechanical disturbance of the epiphysial plate

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

Skeletal scintigraphy, which has now been established as a useful and accurate method of detecting early skeletal metastases and assessing their response to treatment, has been investigated for its pathological basis. Histological examination of several hundred necropsy specimens, from sixty-eight patients who died from malignant disease, showed a significant increase of osteoid and immature woven bone in the presence of metastatic cancer. Tumour-cell suspensions of the VX2 carcinoma were injected into the medullary cavity or on to the periosteal surface of the ilia or tibiae of New Zealand white rabbits. A combination of bone destruction and new bone formation, similar to the autopsy material, was seen. There were at least two mechanisms for the new bone production. Initially, intramembranous ossification was seen in the fibrous stroma surrounding the tumour. Once the cortex was involved and cortical bone destruction had occurred, large amounts of woven bone resembling fracture callus were laid down. The new bone had a markedly increased avidity for boneseeking isotopes, indicating why skeletal scintigraphy was useful. A further twenty rabbits, in whose ilia the VX2 carcinoma was growing, were treated by local irradiation. When treatment was successful the tumour was destroyed, the production of new bone ceased, and the lesion lost its increased avidity for bone-seeking isotopes, indicating that skeletal scintigraphy could be used to assess the response of skeletal metastases to therapy

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

In osteogenesis imperfecta the formation of callus is usually plentiful and sometimes rather excessive but the excess is absorbed in the normal way as consolidation occurs. In hyperplastic callus formation the amount of callus formed is large, or even enormous; and, once its limits are defined and ossification has occurred, some part of the original swelling remains as a thickening of the bone. "Callus" may form with or without injury and with or without fracture. The interest of the present case lies partly in the fact that there is no history of multiple fractures to indicate classical osteogenesis imperfecta, and partly in the familial incidence which has also been noted in other records. It is important to recognise the true nature of the condition in order to avoid the tragedy of unnecessary amputation. In one of Brailsford's cases the lesion is said to have become malignant but there is no other evidence in the literature that the condition has any relationship to malignancy. The clinical appearance can easily give rise to the suspicion of malignancy, and on histological examination the highly cellular and rapidly growing callus can be confused with a malignant condition. In fact, for the short time in which the bone formation runs riot the behaviour of a malignant neoplasm is closely simulated. It is thought that the present account may be of interest because of the invariable relief of pain after x-ray treatment of each new lesion, the length of time over which the case has been followed and the resemblance between the radiographic appearances in the patient now and those of her aunt taken twenty years ago

Aims

Studying the indications for revision total hip arthroplasty (THA) may enable surgeons to change their practice during the initial procedure, thereby reducing the need for revision surgery. The aim of this study was to identify and describe the potentially avoidable indications for revision THA within five years of the initial procedure.

Aims

A number of methods have been described to remove a well-fixed humeral implant as part of revision shoulder arthroplasty. These include the use of cortical windows and humeral osteotomies. The router bit extraction technique uses a high-speed router bit to disrupt the bone-implant interface. The implant is then struck in a retrograde fashion with a square-tip impactor and mallet. The purpose of this study was to determine the characteristics and frequency of the different techniques needed for the removal of a well-fixed humeral stem in revision shoulder arthroplasty.

1. One hundred and seventy-nine cases of primary malignant bone tumour and giant-cell tumour seen at the Middlesex Hospital since 1925 are reviewed. Tumours arising from non-skeletal tissues in bone have been excluded. 2. The following histological classification is used. Osteosarcoma (osteoblast sarcoma): This tumour is not synonymous with osteogenic (bone-forming) sarcoma. The essential feature is the formation of osteoid tissue by malignant osteoblasts, with no intermediate matrix of cartilage or fibrous tissue. It is the most malignant bone tumour and only four of the thirty-two patients survived three years. Chondrosarcoma: These tumours are composed of cartilage, and some show secondary ossification. The behaviour of this group is related to the degree of cartilaginous differentiation. In general, compared with the osteosarcoma, it is of low-grade malignancy. More than half of the sixty-eight patients survived four years. Fibrosarcoma: The essential feature of this tumour is the production of collagen by malignant fibroblastic tumour cells. Tumours of this type invading the medullary cavity have an average prognosis between that of an osteosarcoma and a chondrosarcoma. Nine of the thirty-four patients survived three years. Spindle-cell sarcoma: These tumours are composed of spindle cells which produce no diagnostic matrix. In spite of the lack of differentiation the outlook is not hopeless. Six of the eleven patients survived for five years or more. Giant-cell tumour: This tumour is composed of a cellular stroma with diagnostic giant cells resembling osteoclasts. It is by no means a benign lesion, for half the tumours recurred after treatment and a quarter of the patients died with metastases. 3. The subdivision of primary malignant skeletal tumours into groups according to the histological pattern appears to be reflected in the behaviour of the individual tumours after treatment. The prognosis of each group has been stated in the appropriate sections

Aims

In previous studies, we identified multiple factors influencing the survivorship of hip resurfacing arthroplasties (HRAs), such as initial anatomical conditions and surgical technique. In addition, the University of California, Los Angeles (UCLA) activity score presents a ceiling effect, so a better quantification of activity is important to determine which activities may be advisable or detrimental to the recovered patient. We aimed to determine the effect of specific groups of sporting activities on the survivorship free of aseptic failure of a large series of HRA.

Objectives

Modern metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), while achieving good results with well-orientated, well-designed components in ideal patients, is contraindicated in women, men with head size under 50 mm, or metal hypersensitivity. These patients currently have no access to the benefits of HRA. Highly crosslinked polyethylene (XLPE) has demonstrated clinical success in total hip arthroplasty (THA) and, when used in HRA, potentially reduces metal ion-related sequelae. We report the early performance of HRA using a direct-to-bone cementless mono-bloc XLPE component coupled with a cobalt-chrome femoral head, in the patient group for whom HRA is currently contraindicated.

Objectives

MicroRNAs (miRNAs) have been reported as key regulators of bone formation, signalling, and repair. Fracture healing is a proliferative physiological process where the body facilitates the repair of a bone fracture. The aim of our study was to explore the effects of microRNA-186 (miR-186) on fracture healing through the bone morphogenetic protein (BMP) signalling pathway by binding to Smad family member 6 (SMAD6) in a mouse model of femoral fracture.

Objectives

Re-rupture is common after primary flexor tendon repair. Characterization of the biological changes in the ruptured tendon stumps would be helpful, not only to understand the biological responses to the failed tendon repair, but also to investigate if the tendon stumps could be used as a recycling biomaterial for tendon regeneration in the secondary grafting surgery.

Objectives

Long bone defects often require surgical intervention for functional restoration. The ‘gold standard’ treatment is autologous bone graft (ABG), usually from the patient’s iliac crest. However, autograft is plagued by complications including limited supply, donor site morbidity, and the need for an additional surgery. Thus, alternative therapies are being actively investigated. Autologous bone marrow (BM) is considered as a candidate due to the presence of both endogenous reparative cells and growth factors. We aimed to compare the therapeutic potentials of autologous bone marrow aspirate (BMA) and ABG, which has not previously been done.

Aims

The aim of this study was to conduct the largest low contact stress (LCS) retrieval study to elucidate the failure mechanisms of the Porocoat and Duofix femoral component. The latter design was voluntarily recalled by the manufacturer.