Biomedical subjects

A R Turner-Smith

Publications and source records attributed to A R Turner-Smith.

10 recordsLinked to original sources

PubMed1991

An analysis of normal back shape measured by ISIS scanning.

Two hundred seventy-one school children aged 10-16 years and 72 normal adults aged 21-59 years were scanned by ISIS. Subjects with any evidence of scoliosis were excluded from the study. Characteristic ISIS parameters of back shape showed no statistically significant differences related to age or sex for the children. Back shape in both men and women was not significantly different from that of the children, except for kyphosis angles which were greater.

Adolescent↗

PubMed1991

Familial back shape in adolescent scoliosis. A photogrammetric population study.

A stereophotogrammetric technique (ISIS scanning) was used to assess the back shape of children with adolescent idiopathic scoliosis (index cases), their unaffected relatives, normal adults and children, and children with small idiopathic scoliotic curves (Cobb's angle less than 30 degrees) to detect any familial trends that may predispose to scoliosis. The analysis revealed a characteristic three-dimensional scoliotic back shape; no differences in unaffected relatives as regards sex or a positive family history of scoliosis; similar back shapes in unaffected parents and normal adults, both of whom differ from index cases and children with small curves. Unaffected siblings had a sagittal profile between those of normal children and children with small curves. This may represent an inherited tendency to scoliosis.

Adolescent↗

PubMed1989

Correction of body height in scoliotic patients using ISIS scanning.

Measurement of height in scoliotic patients is complicated by changes in spinal shape in both the coronal and sagittal planes. A method is described by which these changes can be measured and compared with the shape of the normal spine, using an automated stereophotogrammetric technique (ISIS). The resultant height change may be of use in the prediction of respiratory function.

Adolescent↗

PubMed1989

The differentiation of loose and secure femoral implants in total hip replacement using a vibrational technique: an anatomical and pilot clinical study.

ANATOMICAL STUDY: The common pathway to failure in total hip replacements is loosening of the acetabular and femoral components. The reliable diagnosis of this loosening is difficult. A non-invasive technique has been developed which analyses a vibration signal transmitted through the femur. This can distinguish between a femoral component which is loose and one which is firmly fixed. Charnley femoral components were cemented securely into ten cadaver femurs and the transmitted vibration signal recorded. The prostheses were then loosened first at the cement-prosthesis and then at the cement-bone interface. The tests were then repeated. Consistent and distinct differences between output vibration signals were observed between the firmly implanted and the loss prostheses. PILOT CLINICAL STUDY: Seven patients admitted for revision surgery because of clinical and radiological evidence of femoral implant loosening were tested using this technique. A further four patients with secure femoral components were tested approximately two weeks after total hip replacement. The differences in output signal, which had been observed between firmly implanted and loose prostheses during the anatomical study, were again demonstrated.

Adult↗

PubMed1989

Surface stereophotogrammetry of thoracic kyphosis.

The thoracic kyphosis angles of 16 normal individuals, 10 patients with Scheuermann's disease and 11 with adolescent idiopathic scoliosis were measured both radiographically and from Integrated Shape Imaging System (ISIS) scans obtained by surface stereophotogrammetry. There was a high correlation between the two measures. The method of kyphosis measurement from ISIS scans was then used for 30 patients with adolescent idiopathic scoliosis who underwent corrective surgery. A significant reduction in thoracic kyphosis was observed postoperatively. In another group of 28 patients managed conservatively by bracing, some hypokyphosis developed after treatment. However, we found no association between hypokyphosis and curve progression.

Adolescent↗

PubMed1989

Back shape in brace treatment of idiopathic scoliosis.

This preliminary study has shown that bracing may improve the cosmetic appearance of a scoliotic back although the underlying curve remains unchanged. Thirty-two patients treated with the Boston brace for adolescent idiopathic scoliosis were assessed both roentgenographically and by integrated shape imaging system scanning before and after treatment. The mean follow-up time was 16 months. Surface shape improved in 41% of the patients, whereas roentgenographic improvement occurred in only 9%. Roentgenographic measurements should, therefore, be considered in conjunction with corresponding surface shape measurements in the assessment of brace treatment of scoliosis.

Adolescent↗

PubMed1988

A method for analysis of back shape in scoliosis.

The shape of the back is an important factor in the clinical assessment of various spinal disorders, in particular scoliosis. A method of analysis of back surface shape is described which was designed to present most of the numerical parameters needed to assess the progress of the disease as it affects body shape. Measurements of back surface shape and manually marked anatomical landmarks were taken from a television/computer surface measurement system in which a plane of light was scanned over the back and from moiré topographs. The anatomical landmarks were used to define reference planes from which successive analyses were matched. Asymmetry in the transverse plane was illustrated by horizontal cross-sections and skin surface angles. The lateral deformity was shown by an estimate of the line of the vertebral bodies beneath the skin, derived by adding an extra lateral displacement to the palpated positions of the spinous processes, proportional to the rotation of the skin in the transverse plane. This model was used to estimate vertebral end-plate angles and Cobb angles. Lateral sections showed kyphosis and lordosis. Correlations of Lateral Asymmetry from the surface shape analysis with Cobb angle from X-ray measurements in three groups of patients (totalling 119 subjects) were in the range r = 0.77 to r = 0.94, p less than 0.0001. The analysis has reduced follow-up X-ray examinations at the Nuffield Orthopaedic Centre because it indicates quantitatively and with complete safety both lateral asymmetry and deformity in the transverse plane.

Adolescent↗

PubMed1988

A television/computer three-dimensional surface shape measurement system.

An optical scanner is described which has been designed primarily for the measurement of human back shape. A projector and television camera were mounted together in a box which could rotate about a horizontal axis. The projector shone a horizontal plane of light, which was viewed at an angle from below by the television camera, linked directly to a minicomputer. The shape of the line of light formed by the plane as it fell on an object, together with a knowledge of the geometry of the system, enabled three-dimensional coordinates of points on the line to be calculated. A record of a surface shape was built up by scanning the object in about 2 s. Calibration of the system was achieved by scanning an object of known dimensions. Sets of algorithms are described which derive geometric parameters from the calibration scan and which sort surface shape coordinates, outline them and detect special markers from the surface shape scan. The accuracy of measurement exceeded the design aim of +/- 3 mm in each axis within a volume of 400 mm x 500 mm x 300 mm.

Back↗

PubMed1988

ISIS scanning: a useful assessment technique in the management of scoliosis.

The value of surface topographical measurements in the assessment of curve progression in adolescent idiopathic scoliosis is demonstrated in a group of 51 patients. Cobb angles at the commencement of the study ranged from 10 degrees -55 degrees (mean 34.5 degrees), and the mean follow-up period was greater than 2 years. The surface shape method correctly identified curve evolution in 84% of the patient group. Of these, the eight patients who underwent spinal instrumentation were correctly predicted as candidates for surgery.

Adolescent↗

PubMed1988

Scoliosis surgery and its effect on back shape.

Thirty-four patients with adolescent idiopathic scoliosis were assessed by radiography and the integrated shape imaging system (ISIS) both before and after spinal surgery. Twenty-seven patients underwent Harrington instrumentation, after which lateral indices of curvature were significantly improved, but changes in the transverse plane were less pronounced. Sublaminar wiring was carried out in two patients whose thoracic lordosis was corrected by the surgery. Five patients whose severe deformity had persisted after previous spinal surgery underwent costoplasty, which resulted in a significant improvement in back shape measurements. We conclude that the cosmetic deformity of the back in scoliosis is only partially corrected by operations on the spine itself, whilst costoplasty addresses the problem directly, and improves the surface shape.

Adolescent↗