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D Bickerstaff

Publications and source records attributed to D Bickerstaff.

7 recordsLinked to original sources
PubMed2004

Low vision service delivery: an audit of newly developed outreach clinics in Northern Ireland.

Recent publications recommend that low vision services are multi-professional; easily accessible; freely available to all those with visual impairment; monitored by professional and patient groups, and responsive to user feedback. These standards were applied when developing low vision outreach services in Northern Ireland in 1999/2000. Results are reported of the complete clinical audit cycle, coupled with a patient satisfaction telephone questionnaire, which was used to evaluate the service. Of the 48 patients randomly selected from the list of clinic attendees, 28 (58%) were female, 27 (56%) over 80 years of age and 38 (78%) had a primary ocular diagnosis of age related macular degeneration (AMD). Of the 46 low vision aids issued at patients' first appointments, 30 (67%) were illuminated stand magnifiers and 29 (63%) had magnification levels of x5 or less. A total of 46 (96%) patients reported that they had benefited from low vision services.

Aged↗
PubMed2001

BASK Instructional Lecture 4: Anterior cruciate ligament graft fixation.

Anterior cruciate ligament fixation has stimulated an enormous amount of research over the last two decades, particularly with the renewed interest of hamstring reconstruction. This paper summarises our current knowledge on the variety of fixation devices available and points towards possible future advances.

Anterior Cruciate Ligament↗
PubMed1996

Direct measurement of hoop strains in the intact and torn human medial meniscus.

OBJECTIVE: To measure the circumferential or hoop strains generated in the medial meniscus during loading of the knee joint and to examine the effect of longitudinal and radial tears in the meniscus on these strain values. DESIGN: An in vitro investigation measuring the circumferential strains in the medial menisci of cadaveric human knees as they were loaded in a materials testing machine. BACKGROUND: The menisci transmit approximately 50% of the load through the knee, the rest being transmitted by direct contact of the articular cartilage. Damage to the menisci will alter the pattern of load transmission as will meniscectomy. This study examined the changes in the mechanics of the meniscus in situ as a result of simulated tears to assess the effect of its load carrying capacity and the implications of surgery to remove part or all of a damaged meniscus. METHODS: Nineteen human cadaveric knees were tested. Windows were made in the joint capsule and strain gauges inserted into the anterior, middle and posterior sections of the medial meniscus. The knees were then loaded to three times body weight at speeds of 50 and 500 mm/min, with the knee joint at 0 degrees and 30 degrees of flexion. The tests were repeated following the creation of a longitudinal or a radial tear in the meniscus. RESULTS: The intact menisci showed significantly less strain in the posterior section compared to the anterior and middle sections (P < 0.003, with strains of 1.54%, 2.86% and 2.65% respectively). With a longitudinal tear this pattern changed with strains decreasing anteriorly and increasing posteriorly. There were also significant differences at different angles of knee joint flexion not seen in the intact meniscus. 50% radial tears reduced the strains anteriorly whilst a complete radial tear completely defunctioned the meniscus. CONCLUSIONS: This study has shown that there are significantly different hoop strains produced in different sections of the medial meniscus under load and the patterns of strain distribution are disturbed by meniscal tears. RELEVANCE: These results provide important data for mathematical models which must include non-uniform behaviour. They also have implications for the surgical management of torn menisci. Undamaged portions should be preserved and the integrity of the circumferential fibres maintained to ensure the menisci retain a load bearing capability.

Journal Article↗
PubMed1993

Quantitative bone scintigraphy in reflex sympathetic dystrophy.

We have investigated the appearances of the technetium-99m labelled methylene diphosphonate bone scan in 29 scans performed in 16 patients with post-fracture reflex sympathetic dystrophy (RSD) of the hand. There was a close correlation between increased uptake in the metacarpophalangeal joints and the metacarpal bones, suggesting that the increased uptake in RSD is not confined to the periarticular areas as has been previously reported but occurs throughout the affected region. In seven cases examined 3 months after fracture, RSD was associated with a significant increase in uptake at all sites in the hand on the delayed scan which was not seen in matched post-fracture controls, confirming that increased uptake on delayed bone scintography is a sensitive test for the presence of RSD even in the presence of a fracture of the wrist. The early increased uptake gradually returned to normal. Local tenderness assessed by dolorimetry was correlated with increased uptake, suggesting that the bone scan is not only useful as a diagnostic tool but also provides a quantitative indication of the severity of the condition which may be useful in planning and assessing treatments.

Bone and Bones↗
PubMedDate not supplied

The natural history of meniscal tears in anterior cruciate ligament insufficiency.

We reviewed the meniscal status of 176 consecutive patients undergoing anterior cruciate ligament reconstruction acutely (less than 6 weeks from injury), subchronically (6 weeks to 12 months from injury), and chronically (more than 12 months from injury). The commonest tear was the single longitudinal vertical split of the medial meniscus. There was an increasing incidence of meniscal tears as the injury became more chronic, with a significant (P < 0.001) increase in medial meniscal tears; the incidence of lateral meniscal tears remained relatively constant. Seventy-five (43%) of the patients had one or both menisci repaired. Acutely, repair was performed more frequently on the medial meniscus than the lateral (80% versus 24%, respectively). All repaired menisci had single longitudinal tears unstable to probing. The incidence of repair dropped to 46% in the medial meniscus and 14% in the lateral meniscus in the chronic stage. Nineteen (25%) of these 75 patients (26 menisci) underwent a check arthroscopy at a minimum of 6 months from repair. All 21 medial menisci and all 5 lateral meniscal tears had healed; however, 1 lateral meniscus had torn along the line of the sutures. At an average followup of 40 months, 92% of the repaired menisci were still in situ and 8% that had required resection were related to the recurrence of anterior cruciate ligament instability. This study highlights the increasing incidence of meniscal injury in chronic anterior cruciate ligament insufficiency with the meniscal tears becoming more complex and therefore less amenable to suture.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗