Influence of oxygen tension on somatomedin activity in vitro.

Somatomedins are the intermediaries through which growth hormone acts on the epiphyseal growth plate to effect linear skeletal growth. Rat epiphyseal chondrocytes were isolated and cultured in vitro in the presence of somatomedin. Two sources of somatomedin were used, foetal calf serum and rat liver perfusates. The chondrocytes proliferated and synthesized sulphated glycosaminoglycans when grown in the presence of somatomedin from either source, but were not metabolically active in chemically defined medium alone. Some differences in the growth patterns in response to serum or liver somatomedins are reported and discussed. Chondrocyte metabolic activity in the presence of somatomedin in vitro showed a graded response to alterations in the atmospheric oxygen, being greatest at low oxygen pressure, and almost completely inhibited at 95% oxygen. A gradient of local oxygen tension has been reported to exist across the epiphyseal plate in vivo. The effects of somatomedin combined with changing oxygen levels may help to explain the divergence of cell proliferation and matrix synthesis seen in the various regions of the growth plate.

Image analysis derived ploidy and proliferation indices in soft tissue sarcomas: comparison with clinical outcome.

AIMS: To compare prognostic information obtained by image analysis cytometry of paraffin wax embedded soft tissue sarcomas with conventional assessment. METHODS: A CAS 200 image analyser was used to determine DNA content of Feulgen stained cytology preparations and tissue sections and to quantify immunostaining by Ki67 and PC10 antibodies. A mitotic count in 50 high power fields was undertaken and histological grade assigned by the Trojani system. Clinical details including follow up and outcome were obtained by case note review. The Kruskal-Wallis one way analysis test, Spearman rho significance test, Kaplan-Meier method, and log-rank test were applied in statistical analysis. RESULTS: Ploidy status, DNA index, 2.5c exceeding rate, 5c exceeding rate, mitotic count and Trojani grade all correlated significantly with clinical outcome. The relation between Ki67 index and outcome did not reach significance. The PC10 index and outcome were not related. Only 2.5c exceeding rate, 5c exceeding rate, and mitotic count correlated significantly with Trojani grade. CONCLUSIONS: DNA content determination of soft tissue sarcomas by image analysis provides quantifiable information of benefit in prediction of outcome. Larger series are required to determine the independent value of ploidy. In this study quantification of anti-Ki67 and anti-PC10 immunostaining was not of prognostic benefit) by contrast with mitotic count and Trojani grade.

An investigation of occlusive polyester surgical clothing.

The bacterial dispersion rate of people wearing operating room clothing made from several types of polyester fabric was compared to conventional cotton clothing, total-body exhaust gowns and disposable clothing. Airborne bacteria were measured in a chamber, three ultra-clean air operating rooms and a conventionally ventilated operating room. The polyester clothing was demonstrated to be much superior to conventional cotton clothing and at least as good as the total-body exhaust gowns and disposable clothing.

Quantitative gamma-ray computed tomography of the radius in normal subjects and osteoporotic patients.

A new design of gamma-ray computed tomography (CT) scanner was used to measure bone density in 516 normal adults and in 116 female patients with osteoporotic fractures. Trabecular bone density (TBD) was measured for a core of the ultradistal radius; cortical bone mass per unit length (MLS) and mass per unit volume (MVS) were computed for the radius shaft. TBD, MLS and MVS peaked at the age of about 40 in females and fell by 32%, 15% and 24%, respectively, by the age of 65. In males, TBD decreased from the third decade and MLS and MVS peaked in the fourth decade. The corresponding falls by 65 years were 20%, 6% and 7%. In patients with Colles' fracture TBD and MLS were reduced by 13% and 10%, respectively, relative to age matched normal female subjects. For patients with vertebral crush fracture the reductions relative to age matched normal females were 36%, 17% and 16% for TBD, MLS and MVS. In fracture patients the deficit in TBD was significantly greater than that for cortical bone but TBD was no better at discriminating normal and osteoporotic individuals because of its larger normal range. We conclude that gamma-ray CT may best be used for monitoring changes in bone rather than as a diagnostic screening tool.

The pathology of the degenerate meniscus lesion.

The incidence of horizontal cleavage lesions of the menisci was studied in 100 random necropsy examinations. Sixty per cent of subjects had at least one such tear, the incidence being 29 per cent out of the 400 menisci. Eighty-five per cent of the subjects showed changes of osteoarthritis in the patello-femoral or tibio-femoral joint compartments. The coincidence of horizontal cleavage lesion and osteoarthritis was frequent. Horizontal cleavage lesions were commoner in medial or larger menisci and in males. Eighteen per cent of the menisci were calcified and this was twice as common in those menisci with a degenerate tear. Because the horizontal cleavage lesion was so common in the older knee, it must usually remain unrecognised clinically with other factors causing symptoms of night pain and tenderness.

Expression of growth factors, cytokines and matrix metalloproteinases in frozen shoulder.

Frozen shoulder is a chronic fibrosing condition of the capsule of the joint. The predominant cells involved are fibroblasts and myofibroblasts which lay down a dense matrix of type-I and type-III collagen within the capsule. This subsequently contracts leading to the typical features of pain and stiffness. Cytokines and growth factors regulate the growth and function of the fibroblasts of connective tissue and remodelling of the matrix is controlled by the matrix metalloproteinases (MMPs) and their inhibitors. Our aim was to determine whether there was an abnormal expression or secretion of cytokines, growth factors and MMPs in tissue samples from 14 patients with frozen shoulder using the reverse transcription/polymerase chain reaction (RT/PCR) technique and to compare the findings with those in tissue from four normal control shoulders and from five patients with Dupuytren's contracture. Tissue from frozen shoulders demonstrated the presence of mRNA for a large number of cytokines and growth factors although the frequency was only slightly higher than in the control tissue. The frequency for a positive signal for the proinflammatory cytokines Il-beta and TNF-alpha and TNF-beta, was not as great as in the Dupuytren's tissue. The presence of mRNA for fibrogenic growth factors was, however, more similar to that obtained in the control and Dupuytren's tissue. This correlated with the histological findings which in most specimens showed a dense fibrous tissue response with few cells other than mature fibroblasts and with very little evidence of any active inflammatory cell process. Positive expressions of the mRNA for the MMPs were also increased, together with their natural inhibitor TIMP. The notable exception compared with control and Dupuytren's tissue was the absence of MMP-14, which is known to be a membrane-type MMP required for the activation of MMP-2 (gelatinase A). Understanding the control mechanisms which play a part in the pathogenesis of frozen shoulder may lead to the development of new regimes of treatment for this common, protracted and painful chronic fibrosing condition.

Sarcoma at the site of a single hip screw. A case report.

We report a case of malignant fibrous histiocytoma of the hip which occurred 30 years after the insertion of a single chrome-cobalt alloy screw for a slipped femoral epiphysis. The possible aetiological association between malignant tumours and metallic implants is discussed.

Methicillin-resistant Staphylococcus epidermidis in infection of hip arthroplasties.

We investigated the incidence of cephalosporin-resistant bacteria in infected hip arthroplasties. Of 740 patients having hip replacement or related procedures performed over three years, 30 had positive bacteriological cultures from tissue removed at the time of surgery. In 18 of the 30 cultures Staphylococcus epidermidis was grown and 12 of these were methicillin-resistant. A prospective study of skin swabs taken from 100 consecutive patients at the time of admission for THR showed methicillin-resistant Staphylococcus epidermidis in 25. This cephalosporin-resistant organism was shown to be the commonest proven cause of infection, and its presence as a skin commensal raises important questions about current antibiotic prophylaxis for joint replacement.

Surgical stabilisation of the rheumatoid cervical spine. A review of indications and results.

We have reviewed 32 patients with rheumatoid disease of the cervical spine who underwent a total of 40 operations aimed at correcting instability and improving any associated neurovascular deficit. Apart from four patients with intractable pain, the main indication for surgery was progressive neurological impairment. Of the 32 primary operations, 19 (60%) were successful; the remainder failed to achieve their objective and there were two deaths in the immediate postoperative period. Of eight secondary operations performed for recurrence of symptoms or failure to relieve cervical myelopathy, only four were successful. Of nine operations for bony decompression to relieve cord compression from irreducible subluxation, only four were successful. The overall results show a success rate of 57% and a failure rate of 35% with early operative mortality in 8%. Indications for operation are discussed and earlier diagnosis is considered to be the key to improved results.

A bacteriologically occlusive clothing system for use in the operating room.

A comparison was made in a laminar-flow operating room between total-body exhaust gowns and a clothing system made from Fabric 450. This disposable clothing was found to be much more comfortable and convenient than the total-body exhaust gowns. The average airborne bacterial counts obtained during total hip replacement operations from each of the clothing systems were identical when the downflow method of ventilation was used (0.7 per cubic metre) and no significant difference could be demonstrated when the crossflow system was used (2.2 per cubic metre with the total-body exhaust gowns and 3.1 per cubic metre with the disposable clothing). Tests in a dispersal chamber were carried out to find the effectiveness of each item of the disposable clothing in reducing bacterial dispersion. These tests demonstrated the relative ineffectiveness of wearing a surgical gown as compared with wearing the complete system. It was confirmed bacteriologically that the downflow system of ventilation was more efficient than the crossflow type; the importance of this observation with respect to clothing and sepsis is discussed in this paper.

Diagnosis of infection and the role of permanent excision arthroplasty.

The symptoms, signs, and investigation of the infected hip replacement are reviewed. Aspiration, combined with needle biopsy of the interface tissue, gives the best opportunity for establishing a bacteriologic diagnosis. The surgical technique for excision arthroplasty is described, and the complications of this procedure reviewed. The functional results of permanent excision arthroplasty are described in relation to the altered biomechanics of the hip pseudarthrosis.

A comparison of gait symmetry and hip movements in the assessment of patients with monarticular hip arthritis.

Three parameters of hip function have been studied and compared in patients with osteoarthritis of the hip. Clinical indices such as the Harris hip score are cheap and easy to perform but can be misleading. Ground reaction force asymmetries are useful in the assessment of disease severity and treatment outcome and are easy to perform and interpret. The loading rate asymmetries are the most sensitive indicators of this gait dysfunction. Measurement of joint movements using flexible electrogoniometers provides useful functional data but is of limited value if flat walking alone is measured. Whilst none of these tests is entirely reliable each provides valuable information to help with patient assessment.

Surgery of the rheumatoid hip.

The incidence and pattern of involvement of the hip in rheumatoid arthritis are reviewed. The criteria for the selection of patients for surgery are described and the points in preparation emphasised. The surgical procedures available are discussed with the results and complications to be expected. The clinical results of total replacement arthroplasty are gratifying despite the increased incidence of infection and mechanical loosening compared with osteoarthritic hips.

Prospective randomised study of an orthopaedic geriatric inpatient service.

A randomised controlled trial of two management regimens was carried out in women patients over 65 years of age with hip fractures. Ninety seven patients were admitted to a designated orthopaedic geriatric unit and 125 to orthopaedic wards. No difference was observed in mortality, length of stay, or placement of patients between the two groups. More medical conditions were recognised and treated in patients in the orthopaedic geriatric unit group. It is concluded that designated orthopaedic geriatric units can provide medical care to these patients and should be administered without additional cost.