The biomembrane (induced membrane) formed around polymethylmethacrylate (PMMA) spacers has value in clinical applications for bone defect reconstruction. Few studies have evaluated its cellular, molecular or stem cell features. Our objective was to characterise induced membrane morphology, molecular features and osteogenic stem cell characteristics. Following Institutional Review Board approval, biomembrane specimens were obtained from 12 patient surgeries for management of segmental bony defects (mean patient age 40.7 years, standard deviation 14.4). Biomembranes from nine tibias and three femurs were processed for morphologic, molecular or stem cell analyses. Gene expression was determined using the Affymetrix GeneChip Operating Software (GCOS). Molecular analyses compared biomembrane gene expression patterns with a mineralising osteoblast culture, and gene expression in specimens with longer spacer duration (> 12 weeks) with specimens with shorter durations. Statistical analyses used the unpaired student Objectives
Methods
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
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
