The role of imaging in the diagnosis of postural disorders related to low back pain.

The function of the spine in humans is support of the body in an upright position, whilst defying gravity, conserving energy and permitting purposeful movement. Low back pain may either be caused by or result in postural disorders. It is an important cause of lost workdays in the industrialised world, with accompanying social and economic implications, and is a common and disabling problem in many sports. Increased awareness of the potential benefits of exercise, together with a change in attitudes in professional sport (placing greater pressure upon individuals to achieve more spectacular results), have resulted in increased pressure on medical services. This article reviews the examination protocols and clinical applications of the diagnostic imaging modalities available for the evaluation and diagnosis of postural disorders related to low back pain. Conventional radiography continues to be of value in demonstrating skeletal relationships and quantifying spinal kinematics. Computed tomography (CT) is widely available and highly accurate in the evaluation of disc herniation and spinal stenosis. Magnetic resonance imaging (MRI) demonstrates discs and the spinal cord with superb morphological accuracy, is painless and noninvasive, and has no known adverse effects or morbidity. It is the most accurate and sensitive modality for diagnosis of subtle occult changes in low back pains in patients where early preventative measures can be adopted to avoid further damage.

Tissue specific characteristics of cells isolated from human and rat tendons and ligaments.

BACKGROUND: Tendon and ligament injuries are common and costly in terms of surgery and rehabilitation. This might be improved by using tissue engineered constructs to accelerate the repair process; a method used successfully for skin wound healing and cartilage repair. Progress in this field has however been limited; possibly due to an over-simplistic choice of donor cell. For tissue engineering purposes it is often assumed that all tendon and ligament cells are similar despite their differing roles and biomechanics. To clarify this, we have characterised cells from various tendons and ligaments of human and rat origin in terms of proliferation, response to dexamethasone and cell surface marker expression. METHODS: Cells isolated from tendons by collagenase digestion were plated out in DMEM containing 10% fetal calf serum, penicillin/streptomycin and ultraglutamine. Cell number and collagen accumulation were by determined methylene blue and Sirius red staining respectively. Expression of cell surface markers was established by flow cytometry. RESULTS: In the CFU-f assay, human PT-derived cells produced more and bigger colonies suggesting the presence of more progenitor cells with a higher proliferative capacity. Dexamethasone had no effect on colony number in ACL or PT cells but 10 nM dexamethasone increased colony size in ACL cultures whereas higher concentrations decreased colony size in both ACL and PT cultures. In secondary subcultures, dexamethasone had no significant effect on PT cultures whereas a stimulation was seen at low concentrations in the ACL cultures and an inhibition at higher concentrations. Collagen accumulation was inhibited with increasing doses in both ACL and PT cultures. This differential response was also seen in rat-derived cells with similar differences being seen between Achilles, Patellar and tail tendon cells. Cell surface marker expression was also source dependent; CD90 was expressed at higher levels by PT cells and in both humans and rats whereas D7fib was expressed at lower levels by PT cells in humans. CONCLUSION: These data show that tendon & ligament cells from different sources possess intrinsic differences in terms of their growth, dexamethasone responsiveness and cell surface marker expression. This suggests that for tissue engineering purposes the cell source must be carefully considered to maximise their efficacy.

The relationship between surface and radiological deformity in adolescent idiopathic scoliosis: effect of change in body position.

Three-dimensional (3D) surface deformity of the trunk in adolescent idiopathic scoliosis (AIS) is affected by changes in patient position. Initial quantification of the curve and its associated deformity, as well as subsequent monitoring, relies on both radiological and surface measurements. However, there is often a discrepancy between radiological and apparent surface deformity. The present investigation studied the dynamics of the 3D deformity associated with changes in patient position on 27 patients with AIS. The trunk deformity was quantified in three positions by measuring the angle of thoracic inclination at each vertebral level using a scoliometer. The patients all had full spine radiography in the antero-posterior erect position. Vertebral rotation and lateral spinal curvature were measured from the radiographs. Body position altered the magnitude of the surface deformity over the whole trunk, with the prone position offering the optimum relationship between 3D trunk shape and radiological deformity. This could be attributed to the ease and standardisation of positioning for prone measurements, together with increased patient comfort. It is suggested that adoption of standardised positioning and measurement of surface and radiological deformity will permit consistency of clinical judgement based on these parameters.

Effect of cigarette smoking on levels of bioavailable testosterone in healthy men.

The effect of smoking on androgen levels is important given the recent interest in the link between low levels of androgens and the development of cardiovascular disease. Numerous studies examining the effects of cigarette smoking on the levels of total and free testosterone have reported conflicting findings, but there has been no accurate assessment of the effects of cigarette smoking on the levels of bioavailable testosterone [not bound to sex hormone-binding globulin (SHBG)]. We attempted to determine whether smoking affects the level of bioavailable testosterone. We undertook a case-control study of 25 healthy male smokers and 25 healthy never-smokers, matched by age and body mass index. Early morning levels of total, free and bioavailable testosterone, 17beta-oestradiol, SHBG and cotinine were determined and compared between the two groups. Levels of total (18.5+/-4.6 nM versus 15.1+/-4.9 nM, P=0.01) and free testosterone (462+/-91 pM versus 402+/-93 pM, P=0.03) were found to be higher in smokers compared with non-smokers respectively, as was SHBG (34.1+/-12.8 versus 28.1+/-9.0 nM, P=0.06). There were no significant differences in the levels of bioavailable testosterone (3.78+/-1.59 versus 3.51+/-1.26 nM, P=0.49) or 17beta-oestradiol (44.5+/-11.4 versus 42.3+/-11.5 pM, P=0.50) between smokers and non-smokers respectively. These data suggest that cigarette smoking has no significant effect on the biologically active fraction of testosterone, but may influence the levels of total and free testosterone through changes in the levels of SHBG.