Atypical femoral fractures in elderly women

An atypical femoral fracture (AFF), with a transverse fracture radiologically through the lateral cortex is a rare but serious condition. In order to improve our ability to identify patients with this condition, we retrospectively surveyed all subtrochanteric, peri-implant and diaphyseal femoral fractures in patients aged ≥ 65 years who underwent surgical treatment at our hospital between 2004 and 2011.

We describe the incidence of atypical fractures and their characteristics, with observational data including a review of the hospital and general practitioner records. Clinical outcomes were evaluated using the Harris hip score (HHS) and the timed up-and-go (TUG) test.

Atypical fractures only occurred in women with an incidence of 9.8 per 100 000 person-years. The incidence in those who were treated with bisphosphonates was 79.0 per 100 000 person-years; eight of 17 fractures occurred around metal implants. There was a high incidence of delayed union and revision surgery. A total of nine patients (ten AFFs) were available for review at a mean follow-up of 36.5 months (10 to 104). The clinical outcome was poor with a mean HHS of 58.9 (95% CI 47.4 to 70.4) and a mean TUG test of 25.7 s (95% CI 12.7 to 38.8).

The delay in diagnosis and treatment of AFF may result from a lack of knowledge of this condition.

Cite this article: Bone Joint J 2014; 96-B:1035–40.

From intracranial pressure to intracranial pressure wave-guided intensive care management of a patient with an aneurysmal subarachnoid haemorrhage

We report on a 65-year-old female with an aneurysmal subarachnoid hemorrhage (SAH) that was followed clinically, radiologically and electrophysiologically before and after converting from intracranial pressure (ICP)-guided to ICP wave-guided intensive care management. Intracranial pressure-guided management is aimed at keeping mean ICP < 15-20 mmHg, while ICP wave-guided management is aimed at keeping mean ICP wave amplitude < 5 mmHg. The aims of management were obtained by adjusting cerebrospinal fluid (CSF) draining volume from her external ventricular drain. No improvement was seen clinically or in cerebral magnetic resonance imaging (MRI) scans during the ICP-guided management. Clinical, MRI and neurophysiologic (electroencephalography and auditory evoked responses) improvements were obvious within 2 days after converting from ICP- to ICP wave-guided management. This case report describes how we used various ICP parameters to guide intensive care management of an aneurysmal SAH patient.

A formula for the displacement of an arch wire when subjected to a second-order couple

A new formula, expressing the local angular displacement of an orthodontic beam when subjected to a second-order couple applied at midspan, has been developed and analyzed. The computed displacements were compared with the results of ex vivo testing. There was good agreement between the results from the theoretical evaluation and the bench testing. Second-order activation of an orthodontic beam can be described in four sequential phases. The initial displacement is influenced by the second-order clearance between bracket-slot and wire as well as the relationship between the bracket-slot width and interbracket distance. During phase II there is a nonlinear relationship between applied couple and rotational displacement. Within phases three and four displacement is linearly related to the interbracket distance, provided the relationship between the bracket-slot width and interbracket distance remains constant. For a given tooth size, the second-order beam stiffness is exponentially related to bracket width. The experiments also show that even small deflections of thin stainless steel wires can lead to second-order couples of large magnitudes when using a clinically relevant interbracket distance. Consequently, it is important that the orthodontist evaluates his or her choice of bracket width and arch wire stiffness in each clinical case in order to avoid supra-physiologic force levels.

The effects of loops on the torsional stiffnesses of rectangular wires: an in vitro study

Various loop designs have been investigated with respect to the increased torsional flexibility given to the wire by their inclusion. The torsional flexibility of the wire was shown to be enlarged from 26% to 63%, depending on loop design. Both variation in wire cross-section and loop geometry will influence torsional stiffness. Wires with small cross-sectional dimensions will show greater flexibility in torsion. Even small deviations from the stated cross-sectional dimensions can influence the change in torsional stiffness caused by a specific loop design. Inclusion of a reverse-closing loop led to the greatest increase in flexibility, while a Bull loop changed torsional stiffness the least. When vertical flexibility is needed along with reduced torsional stiffness, the T-loop is the loop of choice.

Reproducibility of the 14C urea breath test repeated after 1 week

OBJECTIVES

The aim of this study was to determine the numerical and categorical reproducibility of the 14C urea breath test in a routine clinical setting.

BACKGROUND

The 14C urea breath test is used for diagnosis of Helicobacter pylori infection and is regarded by some centers as the gold standard.

METHODS

In 140 referrals, duplicate tests were performed 1 wk apart. Eighteen patients were excluded because they had taken antibiotics or had changed medication that could influence the gastric urease activity between the tests.

RESULTS

The limits of agreement between the repeated tests were 45-234%. Hence, the numerical result of a repeated test was 95% likely to differ from the first with a factor of approximately two or less. However, when patients were classified as "positive" or "negative" according to our previously determined cut-off limit, only three patients were discordantly classified by the two tests. The observed agreement between the tests was 98%, and the chance-corrected proportional agreement (kappa) was 95%, which is far better than that reported for the histological diagnosis of gastric H. pylori infection.

CONCLUSION

The diagnostic reproducibility of the urea breath test was very good.

An evaluation of the torsional moments developed in orthodontic applications. An in vitro study

The amount of play between brackets and wire and the magnitude of the torsional moments developed have been investigated for six different rectangular wires. The study simulated the situation occurring when torque is applied to an individual central incisor. The observed play between wire and bracket ranged from about 5 degrees between an 0.018 x 0.025 inch in an 0.018-inch bracket slot, to approximately 20 degrees for a 0.016 x 0.022 inch in an 0.018-inch bracket slot. The observed rate of change after the play had been eliminated, varied from 0.24 degrees/Nmm to 0.37 degrees/Nmm for the steel wires, whereas 0.017 x 0.025-inch nitinol had a rate of change of approximately 1.07 degrees/Nmm. The use of ligatures demonstrated that a torque effect could be observed even though the play had not been completely eliminated.