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Biomedical subjects

M K Benson

Publications and source records attributed to M K Benson.

At least 19 recordsLinked to original sources
PubMed2001

Microanatomy of the acetabular cavity and its relation to growth.

The anatomy and development of the growing acetabulum are not clearly understood. We dissected and studied histologically two acetabula from the pelvis of a three-month-old infant. Relative rates of growth at the different growth plates were assessed by comparing the height of the proliferative layer with that of the hypertrophic layer. The three bones which form the acetabulum are surrounded by growth plates on all sides except medially. These face towards the centre of the triradiate cartilage, the limbs of the triradiate cartilage and the articular surface and each may be divided into four distinct areas according to the orientation of its cell columns which reflect the direction of growth. Growth was particularly rapid at the ischial growth plates directed towards the centre and the articular cartilage, add on both sides of the anterior limb of the triradiate cartilage. These findings may explain the mechanism by which the acetabulum changes orientation and inclination with growth.

Acetabulum↗
PubMed2001

The hip in hereditary multiple exostoses.

We defined the characteristics of dysplasia and coxa valga in hereditary multiple exostoses (HME) by radiological analysis of 24 hips in 12 patients. The degree and effect of the 'osteochondroma load' around the hip were quantified. We investigated the pathology of the labrum and the incidence of osteoarthritis and of malignant change in these patients. Coxa valga and dysplasia were common with a median neck-shaft angle of 156 degrees, a median centre-edge angle of 23 degrees and Sharp's acetabular angle of 44 degrees. There was overgrowth of the femoral neck with a significantly greater ratio of the neck/shaft diameter in HME than in the control hips (p < 0.05), as well as correlations between the proximal femoral and pelvic osteochondroma load (p < 0.05) and between the proximal femoral osteochondroma load and coxa valga (p < 0.01). Periacetabular osteochondromas are related to Sharp's angle as an index of dysplasia (p < 0.05), but not coxa valga. No correlation was found between dysplasia and coxa valga. These data suggest that HME may cause anomalies of the hip as a reflection of a generalised inherited defect, but also support the theory that osteochondromas may themselves precipitate some of the characteristic features of HME around the hip.

Adolescent↗
PubMed2001

Reliability of the Severin classification in the assessment of developmental dysplasia of the hip.

This study was undertaken to investigate the reliability of Severin's classification at various ages, and to determine whether the reliability is improved by careful measurement rather than subjective assessment. The radiographs taken at ages 6, 10 and 16 years of 20 randomly selected patients treated for developmental dysplasia of the hip were graded by six observers on two separate occasions using parameters measured according to Severin's criteria. In addition, four of these observers regraded the same radiographs using subjective assessment without measurements being made on two other separate occasions. Agreements between and within observers were evaluated using the weighted Cohen's kappa statistic for each age group. Intraobserver reliability was good, there being a close association between the measured and the subjectively observed ratings. This accords with the subjective nature of this classification. The interobserver reliability was found to be poor although it improved when direct measurements were made. Overall agreement between observers improves as patient age increases. It is concluded that comparisons between different observers using the Severin classification system are not reliable. However, a single investigator comparing treatment modalities in the same study allowing for individual bias in assessing deformity and subluxation would produce reliable results.

Acetabulum↗
PubMed2000

Acetabular dysplasia and failure of development of the ischiopubic synchondrosis: a report of three related cases.

Three cases of acetabular dysplasia associated with failed ossification of the ischiopubic synchondrosis are presented. The patients are second-degree relatives and all skeletally mature with no evidence of other pathological process to delay ossification. A summary of the development of the inferior pubic ramus is presented and the literature of this unusual condition is reviewed.

Acetabulum↗
PubMed2000

Xanthoma disseminatum with respiratory tract involvement and fatal outcome.

Xanthoma disseminatum (XD) is a rare mucocutaneous xanthomatosis classified as a benign form of non-Langerhans' cell histiocytosis. The case history is presented of a 61 year old woman with XD who developed dyspnoea and spirometric features of airflow obstruction. Bronchoscopy and computed tomography confirmed involvement of the large and medium sized bronchi and she subsequently died from acute respiratory failure. The post-mortem findings and the importance of respiratory tract disease in this unusual condition are discussed.

Airway Obstruction↗
PubMed1999

Fatal complication of an expandable metallic bronchial stent.

A case of massive fatal haemoptysis secondary to erosion of a Gianturco expandable wire bronchial stent is described. The stent had been inserted for a benign bronchial stenosis. CT demonstrated erosion of the stent through the oesophagus and a false aneurysm of the descending thoracic aorta. The CT and plain radiographic appearances are presented. The potential for progressive migration and local damage should limit the use of this type of stent in benign bronchial stenoses.

Aneurysm, False↗
PubMed1997

Acetabular notch.

Ultrasound images of dysplastic and/or unstable hips often display an indentation or notch at the superolateral part of the acetabulum where the iliac wing joins the acetabular roof. We reviewed the ultrasound and subsequent radiographic examinations of 295 babies examined in our hip screening clinic. Of the hips with a notch demonstrable at the first ultrasound, 97% had a persistent notch at the second ultrasound and in 79% the notch was apparent on the 3-month radiograph. When the notch persists, we believe that it represents damage to the lateral acetabular ring epiphysis and delayed maturation of the lateral acetabulum.

Acetabulum↗
PubMed1997

The reliability of measurements of pelvic radiographs in infants.

We have evaluated the reliability of the measurement of radiological indicators in developmental dysplasia of the hip. Three observers each independently assessed 60 pelvic radiographs from infants aged from 3 to 36 months. Errors from the true value of a single measurement made by a single observer (E1), of the average of two measurements by a single observer (E2), and of the average of two single measurements by two different observers (E3) were established for the acetabular index of Hilgenreiner, for the assessment of superior and lateral femoral displacement and for indicators of pelvic alignment. The errors for the assessment of the acetabular index were E1 +/- 5 degrees, E2 +/- 5 degrees, and E3 +/- 3.5 degrees. There was a significant correlation between the presence of an acetabular notch on the radiograph and an increased error in measurement (p = 0.01). Yamamuro's measurement of lateral femoral displacement was more reliable than the Hilgenreiner distance. The errors of indicators of pelvic alignment showed a correlation with the age of the infant; the quotient of pelvic rotation was more reliable after seven months of age (p < 0.0001). The errors of the measurement of the symphysis os-ischium angle tended to increase with age and those of the measurement of the index of pelvic tilt decreased with skeletal maturation (p = 0.002).

Child, Preschool↗
PubMed1997

Acute colonic pseudo-obstruction after total hip replacement.

Acute colonic pseudo-obstruction is a poorly recognised and potentially fatal complication of hip surgery. Between 1991 and 1994 six patients were observed who required laparotomy after failure of medical management. In three the indication was signs of peritonism, while in the other three exploration was required to exclude segmental ischaemia and to decompress the bowel. In all, there was no evidence of mechanical obstruction. Patients having total hip replacement are at risk of developing pseudo-obstruction due to their age, comorbidity, high doses of analgesics and the nature of the operation. If postoperative ileus persists for more than 48 hours acute colonic pseudo-obstruction should be suspected and confirmed by plain radiography. Prompt recognition and treatment with early referral to a colorectal unit are indicated. Laparotomy appears to carry less risk than that for patients with idiopathic pseudo-obstruction, but should be performed only if colonic ischaemia is suspected.

Acute Disease↗
PubMed1997

MRI after operative reduction for developmental dysplasia of the hip.

We performed MRI on 13 infants after operative reduction for developmental dysplasia of the hip (DDH). Using an axial gradient-echo sequence, MRI accurately depicted the acetabular anatomy and confirmed adequate reduction in 12 patients. The one patient with redislocation after surgery was correctly identified. MRI can be carried out quickly, inexpensively and without risk of radiation and is the investigation of choice to confirm adequate reduction in DDH.

Casts, Surgical↗
PubMed1996

Removal of femoral sherman plates--not a simple operation.

Surgical removal of a Sherman plate from the femur in an adult treated in childhood for Perthes' disease or developmental dysplasia of the hip (DDH) can be time-consuming and difficult. We analyzed the factors that govern the complexity and complications of plate removal. The notes, operative details, and radiographs of 77 operations for removal of a Sherman plate inserted at the first femoral osteotomy for DDH were assessed. The plates had been in place for 1-32 years and were either completely buried in bone or endosteal in 24%, depending on the time elapsed before removal. Approximately one in five screw heads sheared or required excision, the screw shanks subsequently had to be cored from the bone. The operation took > 90 min in more than one quarter of the patients. The procedure is far from benign. Sherman plates should be removed early when possible, and joint replacement should not be planned to coincide with plate removal. The risks of plate removal must be explained to patients.

Adult↗
PubMed1996

Femoral remodelling after subtrochanteric osteotomy for developmental dysplasia of the hip.

Children who present late with hip dislocation may require femoral osteotomy after reduction, to correct valgus and anteversion deformity of the femoral neck. After these procedures proximal femoral growth is unpredictable. We have studied proximal femoral growth in 40 children who had been treated by femoral osteotomy. Preoperatively, the mean femoral neck-shaft angle was 5 degrees greater on the affected side than on the contralateral side. Postoperatively, it was 28 degrees less. There was progressive recorrection; after five years the angle was not significantly different from that on the contralateral side. In our series 70% of the capital epiphyses became abnormally shaped, taking the appearance of a 'jockey's cap'. All the growth plates became angulated but this corrected with time. Correction of the neck-shaft angle probably results from the more normal mechanical environment provided by reduction. The abnormal radiographic appearance of the epiphysis and growth plate is probably due to the rotation produced by the osteotomy.

Bone Remodeling↗
PubMed1995

Inhaled sodium cromoglycate in angiotensin-converting enzyme inhibitor cough.

Cough is a frequent side-effect of angiotensin-converting enzyme (ACE) inhibitors. We examined the effects of inhaled sodium cromoglycate in 10 patients with ACE-inhibitor cough in a double-blind crossover study. After a 2-week run-in, patients were randomised to either 2 weeks' inhaled sodium cromoglycate or placebo followed by a further 2 weeks on the other treatment. Patients kept a cough diary during each study period. Cough severity was recorded on a scale from 0 to 12. At the end of each study period the cough threshold to inhaled capsaicin was measured. 9 patients reported a reduction in cough after sodium cromoglycate. Median (range) daily cough scores during run-in and placebo periods were 3.6 (1.9-6.4) and 4.1 (0.6-8.1), respectively (p > 0.05). Median daily cough score after sodium cromoglycate was 1.8 (0.4-3; p < 0.01). There was a significant relation between initial cough severity and benefit from sodium cromoglycate; and cough-reflex sensitivity to inhaled capsaicin was significantly reduced. Inhaled sodium cromoglycate is an effective treatment for ACE-inhibitor cough. Its effect may be due to suppression of afferent vagal activity.

Administration, Inhalation↗