PubMed Health⌕ Search

Biomedical subjects

P B Pynsent

Publications and source records attributed to P B Pynsent.

At least 19 recordsLinked to original sources
PubMed1996

The total cost of hip-joint replacement; a model for purchasers.

A computer-based model is used to investigate the total cost of primary total hip-joint replacement. The model takes into account the probability of prosthesis failure, death and re-revision. The results emphasize the importance of age at insertion, demonstrating that the expected life-span of the patient has a major influence on the total cost for a given prosthesis. The discussion considers the idea of a 'lifetime care package' to encapsulate the concept of quality when considering the purchasing of total hip replacements. If it is assumed that a primary replacement episode costs 3500 pounds and revision surgery costs twice as much, then the additional premium on the best implant currently available would be 630 pounds. The premium payable on the same patient using the worst design would be 3080 pounds. This difference reflects the importance of quality in total hip replacement surgery.

Adult↗
PubMed1994

A flowchart-oriented interview language (FOIL) and its application to a low-back pain interview system.

The flowchart-oriented interview language (FOIL) is a computer programme that converts flowchart information into C programming language code. The programme was written to simplify development and maintenance of the Birmingham Back Pain Interview System. In addition FOIL gives the user of the interview system the flexibility of changing the questionnaires to suit their local needs. FOIL may be used for any flowchart-oriented problem. The flowchart specification and the questions are defined in ASCII character files.

Algorithms↗
PubMed1994

The value of computed tomographic measurements in osteosarcoma as a predictor of response to adjuvant chemotherapy.

The response to pre-operative adjuvant chemotherapy was assessed with computed tomography (CT) in 41 osteosarcomas of the long bones of the lower limb. Measurements were made of cross-sectional tumour areas and volumes on both the pre- and post-chemotherapy CT examinations. Changes in these measurements were compared with the percentage necrosis determined from examination of the tumour histology from the excised specimen in 39 cases. An increase in the relative size of the tumour (expressed as a ratio of the pretreatment volume) showed a statistically significant correlation with a poor tumour response as judged by the degree of tumour necrosis. Further analysis of the results showed that quantitative assessment of tumour response by CT is able to identify cases with poor response to therapy (negative predictive value = 0.9). This is, however, only achieved with a low specificity (0.5-0.6). These findings are in agreement with other studies of tumour volume changes using MR imaging.

Adolescent↗
PubMed1994

A comparison of a conventional non-ionic contrast medium (iohexol) alone and with adrenaline and an iso-osmolar non-ionic contrast medium (iotrolan) in computed tomographic arthrography of the shoulder.

The physico-chemical properties of the iso-osmolar dimeric contrast medium iotrolan offers potential advantages in computed tomographic arthrography (CTA). A trial was undertaken comparing iotrolan with iohexol to assess if these theoretical benefits produced an increase in the measured densities in a series of shoulder CTAs. The results showed that iotrolan did produce clinically useful increases in density when compared to a monomeric non-ionic contrast medium. The addition of adrenaline to the monomeric contrast medium produced a significant improvement in the computed tomography density which surpassed that offered by the dimeric contrast medium alone.

Arthrography↗
PubMed1993

Designer hips.

Explore the source record for details and available documents.

Budgets↗
PubMed1990

Pullout force of power-driven staples in cadaveric femoral metaphysis.

The maximum pullout force in the distal metaphysis of cadaver femurs was investigated using a commercially available, pneumatically inserted staple. In paired studies, a significantly greater pullout force was required in the power-driven staples than in an almost identical sized hand-driven staple. A nonlinear relationship was shown to exist between staple-leg length and maximum pullout force.

Adult↗
PubMed1989

Computer interview system for patients with back pain.

We describe a computer-based interview system for patients with back pain. The system uses a light-pen for the patient--computer interface. The questionnaire consists of over 200 multiple and single choice questions. Graphic presentations are used to identify pain patterns. The procedure has been well accepted by patients and is in routine clinical use in several hospitals.

Adolescent↗
PubMed1989

A computer-based interview system for patients with back pain. A validation study.

A microcomputer-based system has been designed to interview patients with a view to investigating and establishing common syndromes of back and leg pain. In a randomized crossover validation study, 50 consecutive outpatients were interviewed by the computer and had a conventional clerking by a doctor. The conventional clerking made minor errors in 3.75% of questions answered and major errors in 0.90%. The computer made minor errors in 6.75% of questions and major errors in 5.45%. The majority of the computer errors were due to inadequate question design. These have been corrected, and it is anticipated that the computer will now have an overall rate of 94% correct answers and be sufficiently accurate to pursue the aim of clinical syndrome identification.

Back Pain↗
PubMed1989

1989 Volvo Award in clinical sciences. Reproducibility of physical signs in low-back pain.

The reproducibility between observers of physical signs in patients with low-back pain was investigated. Fifty patients were examined by two surgeons and another sample of 33 patients was examined by a surgeon and a physiotherapist. Continuous data on five signs were analyzed by Pearsons' correlation coefficient, and binary data on 54 signs were analyzed by the Kappa agreement coefficient. Reliable signs consisted of measurements of lordosis and flexion range, determination of pain on flexion and lateral bend, nearly all measurements associated with the straight leg raising test, determination of pain location in the thigh and legs, and determination of sensory changes in the legs. Signs of root tension showed better agreement when qualified with a description of where the pain was experienced. Bony tenderness was more reliable than soft tissue tenderness.

Adult↗
PubMed1986

The McKee-Farrar hip arthroplasty. A long-term study.

Between 1965 and 1973 a total of 808 McKee-Farrar metal-on-metal cemented total hip arthroplasties were performed in the Norfolk and Norwich Hospital. Of these, 230 surviving arthroplasties have been reviewed at average follow-up of 13.9 years. There were good or excellent results in 49% of the arthroplasties as judged by the Harris hip score with 78% of these having little or no pain. A comprehensive radiographic analysis was undertaken and a survivorship study of 81% of the total number of prostheses is presented.

Adult↗
PubMed1984

Aqueous humour glucose concentration in cataract patients and its effect on the lens.

The glucose concentrations of the blood plasma and aqueous humour were measured in 56 cataract patients. The sodium concentration and colour of the lenses were determined after extraction. The mean plasma and aqueous glucose levels were 5.8 and 3.2 mM respectively in non-diabetic patients, while the values for diabetics were 14.2 and 7.8 mM. The sodium concentration of the lenses from non-diabetic patients appeared to consist of two distributions around 30 and 170 mM, corresponding to nuclear and cortical cataracts respectively. Only two lenses from the non-diabetic patients had sodium concentrations in the range 60-120 mM. In diabetic patients, however, 80% of the extracted lenses had sodium concentrations in this intermediate range. The data indicate that the osmotic stresses induced in the lenses of diabetic and non-diabetic patients are different. The diabetic lenses were also distributed in the middle range when nuclear colour was graded on a scale from I to V, while normal lenses were again normally distributed at either end of the scale.

Aged↗
PubMed1984

Quantitative measurements of joint mobility in adolescents.

Six measurements of joint mobility were made in a group of 446 normal adolescents. A method of measuring hip and knee rotation is presented. All these data are normally distributed, and would suggest that joint hypermobility lies at the end of the normal spectrum. There was a weak but significant correlation between each of the different measures of joint mobility except elbow hyperextention. Criteria for joint laxity are discussed in this age group, and the importance of quantitative techniques of measuring joint mobility are emphasised.

Adolescent↗
PubMed1984

Mechanical factors in the incidence of knee pain in adolescents and young adults.

Mechanical abnormalities of the patellofemoral joint are among the many causes that have been suggested for adolescent knee pain. This study seeks to identify these factors. Measurements of joint mobility and lower limb morphology were made on 446 pupils at a comprehensive school, 136 of whom had suffered knee pain in the previous year. The pupils with symptoms enjoyed sporting activities significantly more than their symptom-free contemporaries. Joint mobility, the Q-angle, genu valgum and anteversion of the femoral neck were not significantly different between those pupils with and those without anterior knee pain. Data on lower limb morphology of normal adolescents are presented. Examination of 52 hospital outpatients aged 13 to 36 years with anterior knee pain produced results comparable with those for the pupils. It is concluded that chronic overloading, rather than faulty mechanics, is the dominant factor in the genesis of anterior knee pain in adolescent patients.

Adolescent↗
PubMed1983

Computer recording of anatomical points in three dimensional space.

A microcomputer based system has been designed to obtain spatial information for orthopaedic measurements, using three potentiometers as the transducer. Both hardware and software are described, including algorithms for converting the raw data to lengths and angles in three dimensional space.

Adolescent↗
PubMed1983

A controlled trial of otis urethrotomy.

Otis urethrotomy is an empirical procedure when used in the treatment of recurrent urinary tract infection and the urethral syndrome. Sixty-four female patients were randomised into two treatment groups. One group had cystoscopy alone and the other cystoscopy and Otis urethrotomy. The patients were assessed pre-operatively and at 6 weeks after surgery both symptomatically and by urodynamic testing. There was no significant difference in the results obtained in the two groups. We conclude that Otis urethrotomy has no advantage in the routine treatment of patients with lower urinary tract symptoms.

Clinical Trials as Topic↗