Ex-vivo Preparat of Femoral Head Clinical Trial
Official title:
The Histological Effect of Various Microfracture Techniques on Human Chondral & Sub-chondral Tissue - an Ex-Vivo Study
The subchondral bone, formed by the subchondral bone plate and the subarticular spongiosa,
plays a key role in supporting the articular cartilage. Marrow stimulation techniques such
as subchondral drilling are clinically important treatment options for symptomatic small
cartilage defects. However, The heat generated from the metal-bone interface during drilling
due to the friction can cause thermal osteonecrosis. , recent clinical evidence suggests
that they may induce alterations in the subchondral bone plate such as intralesional
osteophytes, which persist and may play a role in the degeneration of the repair tissue.
Little is known about whether they induce deleterious changes in the Human Chondral &
Subchondral bone.
The aim of this study was to compare the condral & Sub-chondral Histoligical damage induced
by different drilling techniques.
To the best of our knowledge this is the first time to inspect it, In- Situ, on Human
tissue.
Chronic articular cartilage defects do not heal spontaneously. However, acute traumatic
osteochondral lesions or surgically inflicted lesions extending into subchondral bone,
spongialization, abrasion or microfracture by drilling causing the release of pluripotent
mesenchymal stem cells from the bone marrow, may heal with repair tissue consisting of
fibrous tissue, fibrocartilage or hyaline-like cartilage. There for Marrow stimulation
techniques as subchondral drilling or microfractures represent ones of the most frequently
used methods for chondral and osteochodral defects repair and considered as standard
techniques. [10-12]
It's well know and logical to understand that the high temperature around the drilling hole
can lead to thermal injury. [1] Temperatures over 47 C degrees for one minutes are
associated thermal osteonecrosis [2,3]. The presence of this necrotic bone may delay healing
and predispose to infection.[1] Many studies evaluate the thermal necrosis of the drill into
the bone [3-6]. In case of osteochondral lesion, drilling of the injury area is the most
common practice in orthopedics surgeries for knee, hip, talus and others. In one study that
evaluate the difference between drilling and microfractures and the impact in the cartilage
healing revealed distinct differences between microfracture and drilling for acute
subchondral bone structure and osteocyte necrosis {4] other study evaluate the healing
difference between drilling and burring in rabbits knee, showing degenerative changes in
both technique and histology longer lived repair the cartilage with 2 mm drilling[5] The
main objective of this study is to evaluate for first time in humans, best to our knowledge,
the difference between drilling with KWires compared to drill in terms of thermal
osteonecrosis and histo-pathological damage.
Methodes:
The specimens will be achieved from 2 groups of patients. The first group correspond to
traumatic subcapital fractures with previous non hip pain complains No osteoarthritis
changes in the x-ray. The second group the specimens achieve from hip arthroplasty surgery
due to osteoarthritic changes.
The femoral head will be obtain during surgery. Drill will be performed in 3 contiguous
areas. First Area by Nailing, Second by KW drilling and 3rd area drilled by regular drill
obtaining a triangle with the three drilled epicenters. All will be tested with 2 different
diameters - 3.5 mm & 1.75mm. All 3 methods will be checked with and without cooling - by
laviation with saline during the drilling/nailing. Temperature measurements using
Thermocouples having 1 mm wire diameter will be used for temperature measurement.
Parameters as Drilling speed, Drilling depth and Orientation to line of sress- trabeculae-
would be uniform.
Histological aspect:
The specimen will be fixed with adequate amount of buffered 4% formalin for 24 to 48 hours
with subsequent gentle decalcification in ethylenediaminetetraacetic acid. Then, the
specimen will be cut with a strong knife/ or scalpel into parallel slices 3 to 5 mm thick
and washed in running water for 12 hours. And after this, the sections from abnormal areas,
including articular surface will be submitted for paraffin embedding.
The histological slides will be stained by hematoxilin-eosin (H&E), PAS, Masson trichrome,
and Alcian blue. The lesions (degeneration, hemorrhage, necrosis and others) will be
measured by micrometer in the microscope.
;
Observational Model: Cohort