Introduction: Weber B fractures are one of the most common fractures of the ankle. Unstable fractures are treated with lateral plating and a lag screw. Another method of fixation is antiglide plating, this concept was first introduced by Brunner and Weber in 1982.

Manoli and Schaeffer in 1987, showed that fixation by antiglide plate demonstrated superior static biomechanical properties compared to lateral plating.

However there are some shortcomings in their study and hence we decided to perform our biomechanical study. The shortcomings of the Manoli study are. They did not use an interfragmentary lag screw for lateral plate fixation. It was a cadaveric study where the bone does not accurately represent the live bone. The quality of the bone ranging from normal to osteoporotic bone varies from cadaver to cadaver and hence there is no uniformity between the samples.

Materials and Methods: We used 4th generation composite bone models validated to closely simulate human bone characteristics for fracture toughness, tensile strength, compressive strength, fatigue crack resistance and implant subsidence. 4th generation composite bone model provides uniformity of test samples which is not achievable in cadaveric studies.

These bones were custom made for the experiment. We used two sets of bones, one representative of normal bone (Set A n=10) and the other of osteoporotic bone quality (Set B n=10). Each of the sets A & B will have two types of fixations for artificially created Weber B Fractures.

Lateral plate with interfragmentary lag screw.

The strength of the fixation was measured by restressing the bone until the fixation failed using an Instron machine which simultaneously applied torque and compressive forces to the fibular construct. The resulting data was analysed on a computer and statistical analysis was performed.

Results: When the two fixation constructs were stressed to failure, the lateral plate construct demonstrated less stiffness (3–5Nm/degree) and failed at lower energy levels (250Nm). Similar values obtained for the antiglide system were, stiffness of 12–16Nm/degree and energy absorbed to failure 350–450Nm. Antiglide plating was significantly more stable in the osteoporotic fibula.

Conclusion: Antiglide plating with lag screw is much more stable than lateral plating. It is suitable for treatment without plaster cast post operatively. It results in a more stable fixation in osteoporotic bone.

Introduction: Traditionally the fixation of choice as recommended by the AO ASIF group for transverse fractures of the Olecranon and the Patella is the tension band wiring technique.

The concept of tension band wiring is based on the fact that the distractive force applied to one surface of the bone will result in compression on the opposite articular surface.

Clinical outcomes of TBW are not equivocal. It is associated with significant morbidity such as non union, failure of fixation, especially in osteoporotic bone and infection which sometimes leads to amputation. Often a second procedure for removal of prominent metal work is required.

In our biomechanical study we investigated this concept as we believe that the forces generated by TBW construct do not generate significant compressive forces required for healing of fracture.

Materials and Methods: We used 4th generation composite bones (Sawbones^®, Malmoe, Sweden.). These bone analogues have been validated to closely simulate human bone characteristics for fracture toughness, tensile strength, compressive strength, fatigue crack resistance and implant subsidence.

The advantage of using 4th generation composite bone model is that it provides uniformity which is not achievable in cadaveric studies. Two different bone models representative of Olecranon and patella were used. Transverse fractures were created in the bones and fixed with TBW technique as described in A.O. manual.

Two 0.062-inch Kirschner wires and figure of eight configuration of 18G Stainless steel wire with single knot technique was used. Micro motion transducers (DVRT: MicroStrain, Williston, Vermont) with an accuracy of ± 1μm were placed across the fracture site both anteriorly and posteriorly. Continuous information regarding fracture distraction and compression, as determined by the transducers was recorded from both sites simultaneously during the experiment.

The tension band wire construct was loaded up to a maximum force of 4000 Newtons for patella and 500 for the olecranon. The fractures were subjected to cyclic loading at 1Hz using a servo hydraulic materials-testing system (model 8500; Instron, Canton, Massachusetts). The results were analysed on a computer and statistical analysis performed.

Results: During the application of cyclical loading, we noted a gap at the articular surface ranging from 1.1± 0.4mm and 2.1± 0.6mm for Olecranon and patella constructs respectively. During most of the duration of the experiment no transducer displacements were recorded at the articular surface.

Conclusion: The concept that distractive forces at one end could be converted to compression at the other end through the TBW does not hold true in our biomechanical study. A simpler construct may suffice for fixation of patellar and Olecranon fractures which can reduce the complications associated with TBW fixation.

Introduction: The incidence of osteoporosis is increasing as the population ages. Amongst the recommended treatment modalities for osteoporosis is the use of bisphosphonates. The National Osteoporosis Foundation (U.S.A.) recommends DEXA scanning prior to commencing treatment with bisphosphonate therapy. However, in the Irish setting the availability of DEXA scanning is often limited. We hypothesised that a high percentage of elderly women presenting with fragility fractures of the distal radius (following a simple fall from standing height) had underlying osteoporosis. As such, the initiation of treatment with bisphosphonates prior to obtaining a DEXA scan may be warranted in this patient cohort.

Aim: To assess the incidence of osteoporosis in a continuous cohort of women over 60 years of age presenting with fractures of the distal radius.

Patients and Methods: All female patients aged > 60 years old presenting to the fracture service over a five month period with distal radial fragility fractures were evaluated. Exclusion criteria included:

non-English speakers

100 consecutive patients presenting to the fracture service with distal radial fragility fractures were prospectively identified. Data was collected, including body mass index (BMI), risk factors for osteoporosis, and the OST risk index calculated. A DEXA scan was then performed on the patient’s hips and lumbar spine.

Results: The mean patient age was 74.3 (95%CI + 10.6) years. Mean BMI was 17.3 kg/m2. The mean Osteoporosis Self-assessment Tool (OST) index score was 0.65 correlating with a moderate risk for osteoporosis. The mean T score for the patients’ hips was −2.0 while that for the lumbar spine was −1.7. 64% of patients were osteoporotic with a T score of less than −2.5.

Conclusions A significant incidence of osteoporosis was noted in the study cohort. It is imperative that orthopaedic surgeons recognise the high incidence of osteoporosis in the elderly female population presenting with fragility fractures. The high morbidity and mortality associated with hip and vertebral fractures in this population may be prevented by early treatment of underlying osteoporosis.

Introduction: The increasing popularity of minimal access surgery in orthopaedic surgery has resulted in increasing use of intra-operative fluoroscopy. The radiation dose received by the surgeon varies from procedure to procedure depending on several factors such as duration of procedure, direct exposure to radiation beam and distance from the radiation source. In particular hand and wrist injuries often involve direct fluoroscopic exposure to the hands of the surgeon and assistant during the procedure.

Aim: We undertook a prospective study to directly evaluate the exposure of the surgeon’s and assistant’s hands and thyroid glands during K-wiring procedures of the hand and wrist. In addition we evaluated the efficacy of a lead thyroid shield in limiting the radiation dose to the thyroid gland. In addition we undertook a questionnaire of orthopaedic surgeons and trainees in Ireland to assess the availability of thyroid shields and current practice in wearing them.

Method A total of 30 cases were evaluated. Dosimeter film badges (TLD) were obtained from the Radiological Protection Institute of Ireland (RPI). Two dosimeters were worn by each of the surgical team: one on the dorsum of the dominant hand and a second worn on the neck during the procedure. The number of fluoroscopic exposures, number of times that hands were caught in the image field, the total dosage of radiation for the procedure and the length of time of exposure were recorded. In 20 cases the surgical team undertook standard precautions of a lead jacket. In a random selection of 10 cases the surgical team also wore a thyroid shield.

Results. The mean dose to the surgical teams’ hands was 1.8 cGy (95% CI + 0.6). The mean dose to the thyroid gland was 0.6 cGy in unprotected cases. Notably the dose to the assistants’ hands was higher though this did not reach statistical approval. In cases in which a thyroid shield was worn a significant decrease in dose was noted (p< 0.05). 35% of surgeons had completed a radiation protection course with junior trainees being less likely to have completed such a course.

Conclusion: Significant cumulative radiation dose to the hands and thyroid gland occurs following K-wiring of extremities. The dose to the thyroid gland can be effectively decreased by the use of a thyroid collar. Junior trainees whose operative times and hence radiation exposure are higher, have limited radiation protection training. The mandatory use of thyroid shields and early introduction of radiation protection training may help minimise further radiation exposure.