One commonly used rat fracture model for bone and mineral research
is a closed mid-shaft femur fracture as described by Bonnarens in
1984. Initially, this model was believed to create very reproducible
fractures. However, there have been frequent reports of comminution
and varying rates of complication. Given the importance of precise
anticipation of those characteristics in laboratory research, we
aimed to precisely estimate the rate of comminution, its importance and
its effect on the amount of soft callus created. Furthermore, we
aimed to precisely report the rate of complications such as death
and infection. We tested a rat model of femoral fracture on 84 rats based on
Bonnarens’ original description. We used a proximal approach with
trochanterotomy to insert the pin, a drop tower to create the fracture
and a high-resolution fluoroscopic imager to detect the comminution.
We weighed the soft callus on day seven and compared the soft callus
parameters with the comminution status.Objectives
Methods
Nonunion is one of the most troublesome complications to treat
in orthopaedics. Former authors believed that atrophic nonunion
occurred as a result of lack of mesenchymal stem cells (MSCs). We
evaluated the number and viability of MSCs in site of atrophic nonunion compared
with those in iliac crest. We enrolled five patients with neglected atrophic nonunions of
long bones confirmed by clinical examinations and plain radiographs
into this study. As much as 10 ml bone marrow aspirate was obtained
from both the nonunion site and the iliac crest and cultured for
three weeks. Cell numbers were counted using a haemocytometer and
vitality of the cells was determined by trypan blue staining. The
cells were confirmed as MSCs by evaluating their expression marker
(CD 105, CD 73, HLA-DR, CD 34, CD 45, CD 14, and CD 19). Cells number and
viability were compared between the nonunion and iliac creat sites.Objectives
Methods
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). 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.Objectives
Methods
Neurogenic heterotopic ossification (NHO) is
a disorder of aberrant bone formation affecting one in five patients sustaining
a spinal cord injury or traumatic brain injury. Ectopic bone forms
around joints in characteristic patterns, causing pain and limiting
movement especially around the hip and elbow. Clinical sequelae
of neurogenic heterotopic ossification include urinary tract infection,
pressure injuries, pneumonia and poor hygiene, making early diagnosis
and treatment clinically compelling. However, diagnosis remains
difficult with more investigation needed. Our pathophysiological
understanding stems from mechanisms of basic bone formation enhanced
by evidence of systemic influences from circulating humor factors
and perhaps neurological ones. This increasing understanding guides
our implementation of current prophylaxis and treatment including
the use of non-steroidal anti-inflammatory drugs, bisphosphonates,
radiation therapy and surgery and, importantly, should direct future, more
effective ones.
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. 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. Objectives
Methods
Small animal models of fracture repair primarily investigate
indirect fracture healing via external callus formation. We present
the first described rat model of direct fracture healing. A rat tibial osteotomy was created and fixed with compression
plating similar to that used in patients. The procedure was evaluated
in 15 cadaver rats and then Objectives
Methods
Fractures of the proximal femur are one of the
greatest challenges facing the medical community, constituting a
heavy socioeconomic burden worldwide. The National Hip Fracture
Audit currently provides a framework for service evaluation. This
evaluation is based upon the assessment of process rather than assessment
of patient-centred outcome and therefore it fails to provide meaningful
data regarding the clinical effectiveness of treatments. This study
aims to capture data from the cohort of patients who present with
a fracture of the proximal femur at a single United Kingdom Major
Trauma Centre. Patient-centred outcomes will be recorded and provide
a baseline cohort within which to test the clinical effectiveness
of experimental interventions.
Heterotopic ossification (HO) is perhaps the
single most significant obstacle to independence, functional mobility, and
return to duty for combat-injured veterans of Operation Enduring
Freedom and Operation Iraqi Freedom. Recent research into the cause(s)
of HO has been driven by a markedly higher prevalence seen in these
wounded warriors than encountered in previous wars or following
civilian trauma. To that end, research in both civilian and military
laboratories continues to shed light onto the complex mechanisms
behind HO formation, including systemic and wound specific factors,
cell lineage, and neurogenic inflammation. Of particular interest,
non-invasive
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
The use of two implants to manage concomitant ipsilateral femoral
shaft and proximal femoral fractures has been indicated, but no
studies address the relationship of dynamic hip screw (DHS) side
plate screws and the intramedullary nail where failure might occur
after union. This study compares different implant configurations
in order to investigate bridging the gap between the distal DHS
and tip of the intramedullary nail. A total of 29 left synthetic femora were tested in three groups:
1) gapped short nail (GSN); 2) unicortical short nail (USN), differing
from GSN by the use of two unicortical bridging screws; and 3) bicortical
long nail (BLN), with two angled bicortical and one unicortical bridging
screws. With these findings, five matched-pairs of cadaveric femora
were tested in two groups: 1) unicortical long nail (ULN), with
a longer nail than USN and three bridging unicortical screws; and
2) BLN. Specimens were axially loaded to 22.7 kg (50 lb), and internally
rotated 90°/sec until failure.Objectives
Methods
To investigate the differences of open reduction and internal
fixation (ORIF) of complex AO Type C distal radius fractures between
two different models of a single implant type. A total of 136 patients who received either a 2.4 mm (n = 61)
or 3.5 mm (n = 75) distal radius locking compression plate (LCP
DR) using a volar approach were followed over two years. The main
outcome measurements included motion, grip strength, pain, and the
scores of Gartland and Werley, the Short-Form 36 (SF-36) and the
Disabilities of the Arm, Shoulder, and Hand (DASH). Differences
between the treatment groups were evaluated using regression analysis
and the likelihood ratio test with significance based on the Bonferroni
corrected p-value of <
0.003.Objectives
Methods
The objective of this study was to determine if a synthetic bone
substitute would provide results similar to bone from osteoporotic
femoral heads during Pushout studies were performed with the dynamic hip screw (DHS)
and the DHS Blade in both cadaveric femoral heads and artificial
bone substitutes in the form of polyurethane foam blocks of different
density. The pushout studies were performed as a means of comparing
the force displacement curves produced by each implant within each
material.Introduction
Methods
Negative pressure wound therapy (NPWT) and vessel loop assisted
closure are two common methods used to assist with the closure of
fasciotomy wounds. This retrospective review compares these two
methods using a primary outcome measurement of skin graft requirement. A retrospective search was performed to identify patients who
underwent fasciotomy at our institution. Patient demographics, location
of the fasciotomy, type of assisted closure, injury characteristics,
need for skin graft, length of stay and evidence of infection within
90 days were recorded.Introduction
Methods