Objectives. Because of the contradictory body of evidence related to the
potential benefits of helical blades in trochanteric fracture fixation,
we studied the effect of bone compaction resulting from the insertion
of a proximal femoral nail anti-rotation (PFNA). . Methods. We developed a subject-specific computational model of a trochanteric
fracture (31-A2 in the AO classification) with lack of medial support
and varied the bone density to account for variability in bone properties
among hip fracture patients. Results. We show that for a bone density corresponding to 100% of the
bone density of the cadaveric femur, there does not seem to be any
advantage in using a PFNA with respect to the risk of blade cut-out.
On the other hand, in a more osteoporotic femoral head characterised
by a density corresponding to 75% of the initial bone density, local
bone compaction around the helical blade provides additional bone
purchase, thereby decreasing the risk of cut-out, as quantified
by the volume of bone susceptible to yielding. Conclusions. Our findings indicate benefits of using a PFNA over an intramedullary
nail with a
Objectives. Osteochondral injuries, if not treated adequately, often lead
to severe osteoarthritis. Possible treatment options include refixation
of the fragment or replacement therapies such as Pridie drilling,
microfracture or osteochondral grafts, all of which have certain
disadvantages. Only refixation of the fragment can produce a smooth
and resilient joint surface. The aim of this study was the evaluation
of an ultrasound-activated bioresorbable pin for the refixation of
osteochondral fragments under physiological conditions. Methods. In 16 Merino sheep, specific osteochondral fragments of the medial
femoral condyle were produced and refixed with one of conventional
bioresorbable pins, titanium screws or ultrasound-activated pins.
Macro- and microscopic scoring was undertaken after three months. . Results. The healing ratio with ultrasound-activated pins was higher than
with
Current studies on the additional benefit of using computed tomography
(CT) in order to evaluate the surgeons’ agreement on treatment plans
for fracture are inconsistent. This inconsistency can be explained
by a methodological phenomenon called ‘spectrum bias’, defined as
the bias inherent when investigators choose a population lacking
therapeutic uncertainty for evaluation. The aim of the study is
to determine the influence of spectrum bias on the intra-observer
agreement of treatment plans for fractures of the distal radius. Four surgeons evaluated 51 patients with displaced fractures
of the distal radius at four time points: T1 and T2: conventional
radiographs; T3 and T4: radiographs and additional CT scan (radiograph
and CT). Choice of treatment plan (operative or non-operative) and
therapeutic certainty (five-point scale: very uncertain to very
certain) were rated. To determine the influence of spectrum bias,
the intra-observer agreement was analysed, using Kappa statistics,
for each degree of therapeutic certainty. Objectives
Methods
We aimed to further evaluate the biomechanical characteristics
of two locking screws Synthetic tubular bone models representing normal bone density
and osteoporotic bone density were used. Artificial fracture gaps
of 1 cm were created in each specimen before fixation with one of
two constructs: 1) two locking screws using a five-hole locking
compression plate (LCP) plate; or 2) three non-locking screws with
a seven-hole LCP plate across each side of the fracture gap. The
stiffness, maximum displacement, mode of failure and number of cycles
to failure were recorded under progressive cyclic torsional and
eccentric axial loading.Objectives
Methods
