Management of isolated orbital floor blow-out fractures: a survey of Australian and New Zealand oral and maxillofacial surgeons

Background: This is the first report of involvement of Australian and New Zealand oral and maxillofacial surgeons in the management of isolated orbital floor blow-out fractures and was conducted to obtain comparisons with the results from a recent similar survey of British oral and maxillofacial surgeons. Methods: A questionnaire survey was sent to all 113 practising members of the Australian and New Zealand Association of Oral and Maxillofacial Surgeons in April 2002 with a second mailout 1 month later. Results: Sixty-nine per cent of the respondents were referred isolated orbital floor blow-out fractures for manage-ment, and just over half of these respondents estimated that 50% or more of the cases went to surgery. The materials most commonly used in orbital floor reconstruction were resorbable membrane for small defects and autologous bone for large defects. Conclusion: As in Britain, management of isolated orbital floor blow-out fractures comprises part of the surgical spectrum for many oral and maxillofacial surgeons in Australia and New Zealand. The management protocol was observed to be very similar between the two groups.

Health-protective behaviours and risk of fall-related hip fractures: a population-based case-control study

Background: fall-related hip fractures are one of the most common causes of disability and mortality in older age. The study aimed to quantify the relationship between lifestyle behaviours and the risk of fall-related hip fracture in community-dwelling older people. The purpose was to contribute evidence for the promotion of healthy ageing as a population-based intervention for falls injury prevention. Methods: a case-control study was conducted with 387 participants, with a case-control ratio of 1:2. Incident cases of fall-related hip fracture in people aged 65 and over were recruited from six hospital sites in Brisbane, Australia, in 2003-04. Community-based controls, matched by age, sex and postcode, were recruited via electoral roll sampling. A questionnaire designed to assess lifestyle risk factors, identified as determinants of healthy ageing, was administered at face-to-face interviews. Results: behavioural factors which had a significant independent protective effect on the risk of hip fracture included never smoking [adjusted odds ratio (AOR): 0.33 (0.12-0.88)], moderate alcohol consumption in mid- and older age [AOR: 0.49 (0.25-0.95)], not losing weight between mid- and older age [AOR: 0.36 (0.20-0.65)], playing sport in older age [AOR: 0.49 (0.29-0.83)] and practising a greater number of preventive medical care [AOR: 0.54 (0.32-0.94)] and self-health behaviours [AOR: 0.56 (0.33-0.94)]. Conclusion: with universal exposures, clear associations and modifiable behavioural factors, this study has contributed evidence to reduce the major public health burden of fall-related hip fractures using readily implemented population-based healthy ageing strategies.

Strain and excursion of the sciatic, tibial, and plantar nerves during a modified straight leg raising test

A modified straight leg raising (SLR) in which ankle dorsiflexion is performed before hip flexion has been suggested to diagnose distal neuropathies such as tarsal tunnel syndrome. This study evaluates the clinical hypothesis that strain in the nerves around the ankle and foot caused by ankle dorsiflexion can be further increased with hip flexion. Linear displacement transducers were inserted into the sciatic, tibial, and plantar nerves and plantar fascia of eight embalmed cadavers to measure strain during the modified SLR. Nerve excursion was measured with a digital calliper. Ankle dorsiflexion resulted in a significant strain and distal. excursion of the tibial nerve. With the ankle in dorsiflexion, the proximal excursion and tension increase in the sciatic nerve associated with hip flexion were transmitted distally along the nerve from the hip to beyond the ankle. As hip flexion had an impact on the nerves around the ankle and foot but not on the plantar fascia, the modified SLR may be a useful test to differentially diagnose plantar heel pain. Although the modified SLR caused the greatest increase in nerve strain nearest the moving joint, mechanical forces acting on peripheral nerves are transmitted well beyond the moving joint. (c) 2006 Orthopaedic Research Society.

Effects of early intensive postoperative physiotherapy on limb function after tibial plateau leveling osteotomy in dogs with deficiency of the cranial cruciate ligament

Objective-To determine effects of early intensive postoperative physiotherapy on limb function in dogs after tibial plateau leveling osteotomy (TPLO) for deficiency of the cranial cruciate ligament (CCL). Animals-8 adult dogs with CCL deficiency. Procedure-After TPLO, dogs underwent a physiotherapy program 3 times/wk (physiotherapy group; n = 4) or a walking program (home-exercise group; 4). All dogs were evaluated before surgery, 1 and 10 days after surgery, and 3 and 6 weeks after surgery. Thigh circumference (TC), stifle joint flexion and extension range of motion (ROM), lameness, and weight-bearing scores were recorded. Results-Before surgery, CCL-deficient limbs had significantly reduced TC and reduced flexion and extension ROMs, compared with values for the contralateral control limb. Six weeks after TPLO, the physiotherapy group had significantly larger TC than the home-exercise group, with the difference no longer evident between the affected and nonaffected limbs. Extension and flexion ROMs were significantly greater in the physiotherapy group, compared with values for the home-exercise group, 3 and 6 weeks after surgery. Six weeks after surgery, the difference in flexion and extension ROMs was no longer evident between the affected and nonaffected limbs in the physiotherapy group. Both groups had improvements for lameness and weight-bearing scores over time, but no difference was found between the 2 groups. Conclusions and Clinical Relevance-After TPLO in CCL-deficient dogs, early physiotherapy intervention should be considered as part of the postoperative management to prevent muscle atrophy, build muscle mass and strength, and increase stifle joint flexion and extension ROMs.

Anisotropic properties of human tibial cortical bone as measured by nanoindentation

The purpose of this study was to investigate the effects of elastic anisotropy on nanoindentation measurements in human tibial cortical bone. Nanoindentation was conducted in 12 different directions in three principal planes for both osteonic and interstitial lamellae. The experimental indentation modulus was found to vary with indentation direction and showed obvious anisotropy (oneway analysis of variance test, P < 0.0001). Because experimental indentation modulus in a specific direction is determined by all of the elastic constants of cortical bone, a complex theoretical model is required to analyze the experimental results. A recently developed analysis of indentation for the properties of anisotropic materials was used to quantitatively predict indentation modulus by using the stiffness matrix of human tibial cortical bone, which was obtained from previous ultrasound studies. After allowing for the effects of specimen preparation (dehydrated specimens in nanoindentation tests vs. moist specimens in ultrasound tests) and the structural properties of bone (different microcomponents with different mechanical properties), there were no statistically significant differences between the corrected experimental indentation modulus (Mexp) values and corresponding predicted indentation modulus (Mpre) values (two-tailed unpaired t-test, P < 0.5). The variation of Mpre values was found to exhibit the same trends as the corrected Mexp data. These results show that the effects of anisotropy on nanoindentation measurements can be quantitatively evaluated. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.

Effect of anisotropy on elastic moduli measured by nanoindentation in human tibial cortical bone

Many biological materials are known to be anisotropic. In particular, microstructural components of biological materials may grow in a preferred direction, giving rise to anisotropy in the microstructure. Nanoindentation has been shown to be an effective technique for determining the mechanical properties of microstructures as small as a few microns. However, the effects of anisotropy on the properties measured by nanoindentation have not been fully addressed. This study presents a method to account for the effects of anisotropy on elastic properties measured by nanoindentation. This method is used to correlate elastic properties determined from earlier nanoindentation experiments and from earlier ultrasonic velocity measurements in human tibial cortical bone. Also presented is a procedure to determine anisotropic elastic moduli from indentation measurements in multiple directions. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res.

Recurrent Tibial Tunnel Cyst Formation Following Anterior Cruciate Ligament Reconstruction and Interference Screw Removal

A unique case of a collegiate athlete who suffered an anterior cruciate ligament injury leading to the formation of a synovial cyst is described. The cyst, localized over the tibial tunnel, resulted from irritation caused by the removal of interference screws.

Physeal Growth Plate Fractures: Implications for the Pediatric Athlete

Pediatric musculoskeletal trauma accounts for most childhood injuries. The anatomy and physiology of the pediatric skeleton is unique as is its response to trauma. The pediatric skeleton has periods of rapid growth; therefore the effect of trauma to the musculoskeletal system may have significant long-term complications.

Morbidity and mortality following pelvic rami fractures in an elderly Newfoundland population

Introduction: Pelvic rami fractures in the elderly are associated with significant morbidity and mortality. Despite our rapidly aging population there is a paucity of literature dealing with fractures of the pelvic rami in this age group. The purpose of this study is report mortality rates following these injuries in the Eastern region of Newfoundland. Additionally, we aim to describe and quantify the important resultant morbidity in this vulnerable elderly population . Methods: A retrospective chart review was performed of all the pelvic fractures in individuals over the age of 60 between 2000 and 2005 in the Eastern Health region of Newfoundland and Labrador. From these patients, only those with the radiographic parameters consistent with low energy pattern pelvic ring injuries were included. Excluded from the study were those with concurrent fractures of the femur. Survival data, comorbidities, injury characteristics, hospital stay, ambulatory status, and place of residence were recorded from the chart. A surrogate control group was formulated from Statistics Canada survival data for use as a survival comparison group. Results: There were 80 fractures of the pelvis identified in patients over 60 years old from 2000-2005. Of these, 43 met our inclusion/exclusion criteria and were used in our analysis. The one and five year mortalities of these patients were 16.3% (95% CI; 7.80% to 30.3%) and 58.1% (95% CI; 43.3% to 71.6%), respectively. These were both significantly different from the point estimates from our constructed age and gender matched control group from the Statistics Canada data of 6.58% (one year mortality) and 31.3% (five year mortality). Morbidity was quantified by change in ambulatory status (independent, walker/cane assisted, wheelchair) and change in residential independence (independent, assisted living, nursing home). Post fracture, 36% of patients permanently required increased ambulatory aids and 21% of patients required a permanent increase in everyday level of care. Conclusion: This study suggests that there may be significantly increased mortality and morbidity following low energy pattern pelvic rami fractures in an elderly population compared to age and gender matched controls. In contrast to previous studies describing these injuries, there is greater homogeneity in this population with respect to age and mechanism of injury. This study generates several important hypotheses for future research and in particular highlights the need for larger prospective studies to identify factors predicting the highest risk for poor outcomes in this population.

L'effet d'une variation du niveau d'activité physique sur les propriétés électrophysiologiques des motoneurones du nerf tibial chez le rat

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

L'effet d'une variation du niveau d'activité physique sur les propriétés électrophysiologiques des motoneurones du nerf tibial chez le rat

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.