During the pandemic of COVID-19, some patients with COVID-19 may need emergency surgeries. As spine surgeons, it is our responsibility to ensure appropriate treatment to the patients with COVID-19 and spinal diseases. A protocol for spinal surgery and related management on patients with COVID-19 has been reviewed. Patient preparation for emergency surgeries, indications, and contraindications of emergency surgeries, operating room preparation, infection control precautions and personal protective equipments (PPE), anesthesia management, intraoperative procedures, postoperative management, medical waste disposal, and surveillance of healthcare workers were reviewed. It should be safe for surgeons with PPE of protection level 2 to perform spinal surgeries on patients with COVID-19. Standardized and careful surgical procedures should be necessary to reduce the exposure to COVID-19.

Sixty-two cases of chondrosarcoma of bone were reviewed and histologically graded as low, medium or high-grade tumours. After excluding patients dead from unrelated causes or lost to follow-up, forty cases were available for ten-year follow-up and fifty-eight for five-year follow-up. The rates of survival, recurrence and metastasis were analysed according to the histological grading. Recurrence was further analysed according to the adequacy of treatment. The results were compared with those previously reported in the literature. There was a ten-year survival rate of 58 per cent. Recurrence developed in 58 per cent and was uncontrollable in 29 per cent. The recurrence rate was 87 per cent with inadequate treatment and 15 per cent with adequate treatment. Recurrences outside the limb bones usually proved uncontrollable; recurrences in the limb bones were amenable to further, and if necessary repeated, operations. High-grade chondrosarcoma had a metastatic risk of 75 per cent and eventual mortality of 88 per cent. Medium-grade chondrosarcoma had a metastatic risk of 14 per cent and a mortality of 60 per cent. Low-grade chondrosarcoma had a metastatic risk of 5 per cent and a mortality of 29 per cent

Midline prolapse of a disc causing compression of the cauda equina is rare but needs urgent diagnosis and surgical treatment. The onset of bladder and rectal paralysis with saddle anaesthesia should be viewed with a high index of suspicion in a patient with backache and sciatica. Eight cases were seen over a period of five years, and they fell into three clinical groups. Group I patients presented with a sudden onset without any previous symptoms related to the back. Group II patients had a history of recurrent episodes of backache and sciatica, the latest episode resulting in involvement of the cauda equina. The group III patient was indistinguishable from one with a tumour as he presented with backache and sciatica slowly progressing to paralysis of the cauda equina. The prolapse was at the disc between L5 and S1 vertebrae in 50 per cent of the patients, most of whom did not have any limitation of straight leg raising. Urgent myelography and equally urgent removal of the disc within two weeks of the onset of the symptoms resulted in almost complete motor and bladder recovery within five months after the operation in most cases. However, recovery of sensation and sexual function was incomplete even four years after the operation

1. Bones consist essentially of bundles of collagenous fibres united by a cementing substance in which the inorganic material lies in the form of minute plate-like crystals. 2. During weight bearing and muscle action bones as a whole are deformed to a variable extent. Periods of deformation are followed by periods of relaxed pressure during which the bones tend to return to their normal form. 3. These variations in deformation and elastic recoil set up alternating pressures and tensions within the bones along the bone cyrstal encrusted fibres which make up the trabeculae, lamellae and Haversian systems, and these alternating phases of compression and tension stimulate the activity of osteoblasts so that bone formation predominates over bone resorption. 4. These alterations of pressure and tension are intermittent and reciprocal in nature and do not, as postulated by the trajectorial theory, involve different trabeculae, nor is it necessary to consider whether tension or pressure is the more important phase in determining bone deposition. 5. The pressure exerted by cysts, tumours, erupting teeth, etc., is of a quite different nature, as is the response to trauma or callus formation in the healing of fractures. These processes are essentially vascular phenomena involving localised areas of bony tissue and not bones as mechanical units

Sarcoma complicating Paget's disease is uncommon; ninety-five cases have been collected and seven further cases are now reported. Sarcoma probably complicates less than 2 per cent of all cases of Paget's disease. There is a relatively high incidence in males, especially in the sixth decade, whereas bone sarcoma over the age of fifty years without osteitis deformans is rare. Injury is prominent in the history of many cases. Comparison of Paget's sarcoma, "ordinary" bone sarcoma and the bones affected by uncomplicated osteitis deformans reveals some important differences. As to the type of tumour, osteogenic sarcoma is the commonest, but fibrosarcoma and round-cell sarcoma are also frequent. The serum phosphatase is a most useful prognostic guide in a disease with a generally poor prognosis. Magnesium metabolism in relation to bone sarcoma requires further study. Prophvlaxis is based on a clinical suspicion of this complication in Paget's disease, and measures are outlined which may be of assistance. Sarcoma in Paget's bone is highly lethal, but Nature in striking down these old people may have provided us with facts which will ultimately solve problems common to all sarcomas of bone

We assessed the intermediate functional results of eight patients after wide resection of the proximal humerus for malignant bone tumour. We used a free vascularised fibular graft as a functional spacer and a sling procedure to preserve passive scapulohumeral movement. Scapulohumeral arthrodesis was not carried out. Five patients had osteosarcoma, two achondrosarcoma and one a malignant fibrous histiocytoma of the bone. The mean duration of follow-up was 70 months (median, 76) for the seven patients who were still alive at the time of the latest follow-up. One patient died from the disease 12 months after surgery. There were no local recurrences. The functional results were described and graded quantitatively according to the rating system of the Musculoskeletal Tumour Society. Our results were satisfactory with regard to pain, emotional acceptance and manual dexterity. Function and lifting ability were unsatisfactory in two patients. One patient had delayed union between host and graft, but this united after six months without further surgery. Radiographs of the shoulder showed absorption or collapse of the head of the fibula in four of the eight patients and a fracture in another. No functional problems related to absorption or fracture of the head of the fibula were noted. There was no infection or subluxation of the head. We conclude that this is a reasonably effective technique of limb salvage after resection of the proximal humerus

Aims

Complex displaced osteoporotic acetabular fractures in the elderly are associated with high levels of morbidity and mortality. Surgical options include either open reduction and internal fixation alone, or combined with total hip arthroplasty (THA). There remains a cohort of severely comorbid patients who are deemed unfit for extensive surgical reconstruction and are treated conservatively. We describe the results of a coned hemipelvis reconstruction and THA inserted via a posterior approach to the hip as the primary treatment for this severely high-risk cohort.

1. The incidence of osteogenic sarcoma, chondrosarcoma and Ewing's sarcoma in relation to age, sex and site is analysed in a study of 832 malignant primary bone tumours diagnosed in Sweden in 1958-68. The results are compared with those in other series. 2. The adolescent incidence peak for osteogenic sarcoma is caused by tumours localised to the long bones of the lower limb. The peak incidence occurs at a mean age of twelve years for girls and sixteen years for boys and is associated with the maximum growth velocity for the adolescent growth spurt. 3. Ewing's sarcoma, showing no sex difference with regard to its incidence peak, seems not to be associated with bone growth. 4. In the adult, the incidence of osteogenic sarcoma parallels that of chondrosarcoma, thus showing a successive increase with increasing age. In Sweden, where Paget's disease is uncommon, the incidence of osteogenic sarcoma over the age of thirty is only one-third of that during adolescence. 5. In osteogenic sarcoma and chondrosarcoma but not in Ewing's sarcoma, the characteristic predominance of males over females is valid only for localisations to the long bones of the lower limb, the pelvis and the spinal column and not for other sites. Internal factors such as age, sex, bone growth and maturation and also weight-bearing seems to be of importance in modifying the response of the tissue to a causative external factor, like a common virus

Autogenous bone graft which has been either autoclaved or irradiated is commonly used in oriental countries as an alternative to allograft. We started to use the technique of extracorporeal irradiation of the resected specimen and reimplantation (ECIR) in 1991. There was, however, a high incidence of fracture of the irradiated bone and loss of articular cartilage. In an attempt to reduce these complications, we combined the irradiated autograft with a conventional arthroplasty. Between 1995 and 1998, 14 patients underwent limb salvage by this method. Seven had an osteosarcoma, two bony metastases, three a chondrosarcoma, one a malignant fibrous histiocytoma, and one a leiomyosarcoma. Ten tumours were located in the proximal femur, two in the proximal humerus, and two in the distal femur. One patient who had a solitary metastasis in the proximal part of the left femur died from lung metastases 13 months after operation. The remaining 13 patients were alive and without evidence of local recurrence or distant metastases at a mean follow-up of 43 months (28 to 72). Postoperative palsy of the sciatic nerve occurred in one patient, but no complications such as wound infection, fracture, or nonunion were seen. All host-irradiated bone junctions healed uneventfully within eight months. Using the Enneking functional evaluation system, the mean postoperative score for all 14 patients was 80% (57 to 93). The use of irradiated autograft prosthesis composites reduces the complications of ECIR and gives good functional results. It may be a good alternative in limb-salvage surgery, especially in countries where it is difficult to obtain allografts

Our aim was to determine whether in vitro studies would detect differences in the cellular response to wear particles of two titanium alloys commonly used in the manufacture of joint replacement prostheses. Particles were of the order of 1 μm in diameter representative of those found adjacent to failed prostheses. Exposure of human monocytes to titanium 6-aluminium 4- vanadium (TiAlV) at concentrations of 4 x 10. 7. particles/ml produced a mean prostaglandin E. 2. release of 2627.6 pM; this was significantly higher than the 317.4 pM induced by titanium 6-aluminium 7-niobium alloy (TiAlNb) particles (p = 0.006). Commercially-pure titanium particles induced a release of 347.8 pM. In addition, TiAlV stimulated significantly more release of the other cell mediators, interleukin-1, tumour necrosis factor and interleukin-6. At lower concentrations of particles there was less mediator release and less obvious differences between materials. None of the materials caused significant toxicity. The levels of inflammatory mediators released by phagocytic cells in response to wear particles may influence the amount of periprosthetic bone loss. Our findings have shown that in vitro studies can detect differences in cellular response induced by particles of similar titanium alloys in common clinical use, although in vivo studies have shown little difference. While in vitro studies should not be used as the only form of assessment, they must be considered when assessing the relative biocompatibility of different implant materials

We describe a method of partial limb salvage for the treatment of large primary malignant tumours of the arm. The tumour-bearing area is resected as a cylindrical segment and the distal arm is then replanted with the necessary shortening. The method is suitable for stage-IIB tumours with or without neurovascular involvement which, because of their extent, could otherwise be adequately treated only by amputation. From 1987 to 1992 we used this method in 12 patients with primary malignant bone or soft-tissue sarcomas. Wide resection margins were achieved in all, but six patients died from their disease at a mean of 21.5 months (6 to 48), none with any local recurrence. Five patients have no evidence of disease at a mean follow-up period of 52.2 months (22 to 78), and one was lost to follow-up at 48 months postoperatively when there was no evidence of disease. The results of the functional evaluation of ten patients with a follow-up of over ten months were excellent in one, good in six and fair in three, by the criteria of Enneking (1987). Recovery after nerve reconstruction was satisfactory in all cases with sensation S3 or higher and motor function M2+ or higher. Detailed evaluation of hand function on the Millesi score rated only 22% (9.6% to 33.7%) as compared with the contralateral side, but the patients were satisfied and refused further operations for the improvement of function. These oncological and functional results allow us to recommend resection-replantation as a valuable alternative to amputation for the treatment of primary malignant tumours of the arm

The role of radiotherapy and/or surgery in the local treatment of Ewing’s sarcoma has still to be determined. The outcome of Ewing’s sarcoma may differ according to its location and a selection bias towards surgery limits the ability to compare methods of local treatment. We have carried out a retrospective review of 91 consecutive patients treated for non-metastatic Ewing’s sarcoma of the femur. They received chemotherapy according to four different protocols. The primary lesion was treated by surgery alone (54 patients), surgery and radiotherapy (13) and radiotherapy alone (23). One was treated by chemotherapy alone. At a median follow-up of ten years, 48 patients (53%) remain free from disease, 39 (43%) have relapsed, two (2%) have died from chemotherapeutic toxicity and two (2%) have developed a radio-induced second tumour. The probability of survival without local recurrence was significantly (p = 0.01) higher in patients who were treated by surgery with or without radiotherapy (88%) than for patients who received radiotherapy alone (59%). The five- and ten-year overall survival rates were 64% and 57%, respectively. Patients who were treated by surgery, with or without radiotherapy, had a five- and ten-year overall survival of 64%. Patients who received only radiotherapy had a five- and ten-year survival of 57% and 44%, respectively. Our results indicate that in patients with Ewing’s sarcoma of the femur, better local control is achieved by surgical treatment (with or without radiotherapy) compared with the use of radiotherapy alone. Further studies are needed to verify the impact of this strategy on overall survival

The interactions between the different cell types in periprosthetic tissue are still unclear. We used a non-contact coculture model to investigate the effects of polymethylmethacrylate (PMMA) particles and human macrophage-derived soluble mediators on fibroblast activation. Macrophages were either exposed or not exposed to phagocytosable PMMA particles, but fibroblasts were not. Increasing numbers of macrophages were tested in cocultures in which the fibroblast cell number was held constant and cultures of macrophages alone were used for comparison of cytokine release. We used the release of interleukin-1 beta (IL-1β), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-α), lysosomal enzyme and metalloproteinase activity to assess the cultivation of macrophages and fibroblasts. In cocultures, IL-6 release was increased 100-fold for both unchallenged and particle-challenged cultures when compared with macrophage cultures alone. Furthermore, particle-challenged cocultures had threefold higher IL-6 levels than unchallenged cocultures. Release of TNF-α was similar in cocultures and in macrophage cultures. IL-1β release in cocultures was independent of the macrophage-fibroblast ratio. Lysosomal enzyme activity and metalloproteinase activity were increased in cocultures. Our data show that macrophages and fibroblasts in coculture significantly increase the release of IL-6 and to a less degree other inflammatory mediators; particle exposure accentuates this effect. This suggests that macrophage accumulation in fibrous tissue may lead to elevated IL-6 levels that are much higher than those caused by particle activation of macrophages alone. This macrophage-fibroblast interaction represents a novel concept for the initiation and maintenance of the inflammatory process in periprosthetic membranes

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.

The pathogenesis of aseptic loosening of total joint prostheses is not clearly understood. Two features are associated with loosened prostheses, namely, particulate debris and movement of the implant. While numerous studies have evaluated the cellular response to particulate biomaterials, few have investigated the influence of movement of the implant on the biological response to particles. Our aim was therefore to test the hypothesis that excessive mechanical stimulation of the periprosthetic tissues induces an inflammatory response and that the addition of particulate biomaterials intensifies this. We allocated 66 adult Beagle dogs to four groups as follows: stable implants with (I) and without (II) particulate polymethylmethacrylate (PMMA) and moving implants with (III) and without (IV) particulate PMMA. They were then evaluated at 2, 4, 6, 12 and 24 weeks. The stable implants were well tolerated and a thin, fibrous membrane of connective tissue was observed. There was evidence of positive staining in some cells for interleukin-6 (IL-6). Addition of particulate PMMA around the stable implants resulted in an increase in the fibroblastic response and positive staining for IL-6 and tumour necrosis factor-alpha (TNF-α). By contrast, movement of the implant resulted in an immediate inflammatory response characterised by large numbers of histiocytes and cytokine staining for IL-1ß, TNF-α and IL-6. Introduction of particulate PMMA aggravated this response. Animals with particulate PMMA and movement of the implant have an intense inflammatory response associated with accelerated bone loss. Our results indicate that the initiation of the inflammatory response to biomaterial particles was much slower than that to gross mechanical instability. Furthermore, when there was both particulate debris and movement, there was an amplification of the adverse tissue response as evidenced by the presence of osteolysis and increases in the presence of inflammatory cells and their associated cytokines

1. The clinical features of hyperostosis cranii are briefly reviewed. In large series of cases the syndrome has been found to occur almost entirely in females. 2. In recent studies of dystrophia myotonica, it is apparent that hyperostosis cranii is one of the variable features of the disorder. This disease occurs equally among males and females and the hyperostosis cranii also is distributed equally among males and females. 3. Hyperostosis cranii also occurs in patients with Morgagni's syndrome, with acromegaly, and as "senile hyperostosis.". 4. The etiology of hyperostosis is still a matter for speculation. More recent studies have focused attention on the endocrine system, and it seems probable, in view of the sex distribution in dystrophia myotonica, that the key to the problem may be found in this disorder. 5. In dystrophia myotonica the characteristic skull changes are hyperostosis cranii, a small pituitary fossa, excessive sinus formation and prognathism. These are acromegaloid changes. Gonadal atrophy is a common feature and endocrine study suggests that the endocrine defect is primarily a failure of the androgenic function of the adrenals and the testes. 6. In rodents and in humans ablation of the gonads leads to overactivity of gonadotrophic cells and, at times, of somatotrophic cells. Sometimes pituitary tumours develop. 7. Acromegaloid features may occur in eunuchs, and it is likely that the acromegaloid changes in dystrophia myotonica are of the same order from overactivity of growth hormone. 8. In animals excess of growth hormone produces thickening of the skull. 9. In dystrophia myotonica, acromegaly, and Morgagni's syndrome, it is suggested that hyperostosis cranii is an expression of unrestrained activity of growth hormone