Bone healing By,M. Thiru murugan Bone healing: Bone healing is a regenerative process in which bone is restored without scar tissue formation. Also called fracture healing Bone fractures are a common injury and the healing process is complex.  Bone is one of a few tissues that is able to heal without forming a fibrous scar. There are two types of fracture healing: Direct healing (primary) Indirect (secondary) Bone healing take place through different stages Direct/ primary healing occurs when the bony fragments are fixed together with compression. There is no callus formation. The bony ends are joined and healed by osteoclast and osteoblast activity.  Indirect healing is more common than direct healing and involves both endochondral and intramembranous bone healing. Anatomical reduction and stable conditions are not required for indirect healing to occur.  Rather, there is a small amount of motion and weight-bearing at the fracture, which causes a soft callus to form, leading on to secondary bone formation. It should be noted though that too much load/movement can result in delayed healing or non-union. Stages of bone healing: i) Hematoma formation: Blood vessels in the broken bone tear and hemorrhage, resulting in the formation of clotted blood, or a hematoma, at the site of the break. The severed blood vessels at the broken ends of the bone are sealed by the clotting process. Bone cells deprived of nutrients begin to die.   ii) Bone generation: Within days of the fracture, capillaries grow into the hematoma, while phagocytic cells begin to clear away the dead cells. Though fragments of the blood clot may remain, fibroblasts and osteoblasts enter the area and begin to reform bone. Fibroblasts produce collagen fibers that connect the broken bone ends, while osteoblasts start to form spongy bone. The repair tissue between the broken bone ends, the fibro cartilaginous callus is composed of both hyaline and fibrocartilage Some bone spicules may also appear at this point. iii)Bony callous formation: The fibro cartilaginous callus is converted into a bony callus of spongy bone. callus - a type of soft bone replaces the blood clot that formed in the inflammatory stage. The callus holds the bone together, but isn't strong enough for the body part to be used. Over the next few weeks, the soft callus becomes harder. It takes about two months for the broken bone ends to be firmly joined together after the fracture. This is similar to the endochondral formation of bone when cartilage becomes ossified; osteoblasts, osteoclasts, and bone matrix are present. iv) Bone remodeling: The bony callus is then remodelled by osteoclasts and osteoblasts, with excess material on the exterior of the bone and within the medullary cavity being removed. Compact bone is added to create bone tissue that is similar to the original, unbroken bone. This remodeling can take many months; the bone may remain uneven for years   Factors Affect Bone Healing Patient

1. Bone healing

2. • Bone healing:
• Bone healing is a regenerative process in which bone
is restored without scar tissue formation. Also called
fracture healing
• Bone fractures are a common injury and the healing
process is complex.
• Bone is one of a few tissues that is able to heal without
forming a fibrous scar.
• There are two types of fracture healing:
1. Direct healing (primary)
2. Indirect (secondary)
• Bone healing take place through different stages

3. • Direct/ primary healing occurs when the bony fragments
are fixed together with compression. There is no callus
formation. The bony ends are joined and healed by
osteoclast and osteoblast activity.
• Indirect healing is more common than direct healing and
involves both endochondral and intramembranous bone
healing.
• Anatomical reduction and stable conditions are not required
for indirect healing to occur.
• Rather, there is a small amount of motion and weight-
bearing at the fracture, which causes a soft callus to form,
leading on to secondary bone formation.
• It should be noted though that too much load/movement
can result in delayed healing or non-union.

4. • Stages of bone healing:
• i) Hematoma formation: Blood vessels in the broken
bone tear and hemorrhage, resulting in the formation of
clotted blood, or a hematoma, at the site of the break. The
severed blood vessels at the broken ends of the bone are
sealed by the clotting process. Bone cells deprived of
nutrients begin to die.

5. • ii) Bone generation: Within days of the
fracture, capillaries grow into the
hematoma, while phagocytic cells begin to
clear away the dead cells.
• Though fragments of the blood clot may
remain, fibroblasts and osteoblasts enter
the area and begin to reform bone.
• Fibroblasts produce collagen fibers that
connect the broken bone ends, while
osteoblasts start to form spongy bone.
• The repair tissue between the broken bone
ends, the fibro cartilaginous callus is
composed of both hyaline and
fibrocartilage Some bone spicules may also
appear at this point.

6. • iii)Bony callous formation: The fibro
cartilaginous callus is converted into a
bony callus of spongy bone.
• callus - a type of soft bone replaces the
blood clot that formed in the
inflammatory stage. The callus holds
the bone together, but isn't strong enough
for the body part to be used. Over the next
few weeks, the soft callus becomes harder.
• It takes about two months for the broken
bone ends to be firmly joined together
after the fracture. This is similar to the
endochondral formation of bone when
cartilage becomes ossified; osteoblasts,
osteoclasts, and bone matrix are present.

7. • iv) Bone remodeling: The bony
callus is then remodelled by
osteoclasts and osteoblasts, with
excess material on the exterior of the
bone and within the medullary cavity
being removed.
• Compact bone is added to create bone
tissue that is similar to the original,
unbroken bone.
• This remodeling can take many
months; the bone may remain uneven
for years

8. Stages of bone healing:

9. • Factors Affect Bone Healing
• Patient with nutritional deficits, smoking, and diabetic
patient will experience delayed bone healing.
• Parathyroid hormones have a vital role in bone healing
• Aging process affect bone healing
• Chronic inflammation delay the bone healing
• Infection of the fracture site at healing process.
• Insufficient formation of cartilage within fracture gap
and marrow space.
• Open, comminuted fracture, and the extent of soft
tissue injury also show delayed union healing