Bone Structure

Compact Bone and Spongy Bone

Skeletal System Functions

• Support for the body.

• Protection for organs.

• Hematopoiesis - the production of blood cells. (WBC’s, RBC’s and platelets)

• Storage and release of Ca+2 and P-3

• Mechanical transmission of muscle forces.

Compact Bone StructureNote the tree ring like structure of the osteons. Each ring is a lamellae. The cells (osteocytes) are embedded in the bone (lacunae) but they receive nourishment and they have connections with each other through the canaliculi.

Spongy Bone.Contains large marrow spaces defined by spicules of bone. The inner space is lined by osteoblasts and osteoclasts (called the endosteum). Osteocytes can be seen in layers in adult spongy bone.

bone formation

Red Bone Marrow• Red Bone-

marrow is a soft, fatty tissue found inside of certain bones mostly in spongy bone tissue.

• It produces blood cells (red blood cells, white blood cells, and platelets) from adult stem cells.

• Red blood cells carry oxygen throughout the body.

• White blood cells act to ward off infection.

• Platelets aid in blood-clotting.

Bone Marrow Transplants• Can correct deficiencies in red blood cells (aplastic anemia) and white blood cells (leukemia or lymphoma).

• Ease aggressive cancer treatments (chemotherapy or radiation therapy).

• inherited (genetic) diseases (such as thalassemia)

• immune-system disorders (such as congenital neutropenia

• Severe-combined immunodeficiency syndrome)

• The first successful bone marrow transplant took place in 1968 at the University of Minnesota.

• The recipient was a child with severe combined immunodeficiency disease and the donor was a sibling.

Bone Marrow Transplants• While the donor is awake

and anesthetized, bone marrow is removed from the top of the hip bone (iliac crest).

• The bone marrow is filtered, treated, and transplanted immediately.

• Other times it's frozen and stored for later use.

• The bone marrow is then transfused through a vein (IV line).

• It naturally transports itself back into the intended bone cavities, where it grows quickly to replace the old bone marrow.

Bone Marrow Transplants

• It is difficult to find donors, and the cost of surgery is very high.

• The donor is usually a sibling with compatible tissue.

• Sometimes, unrelated donors act as a source for bone-marrow transplants.

• The hospitalization period is three to six weeks.

• During this time, the recipient is isolated and monitored because of the increased risk of infection.

• Follow-up care is required for two to three months after discharge from the hospital.

• It takes six months to a year for the immune system to fully recover from this procedure.

• Relatively normal activities are resumed.

• bone marrow transplant

Osteoblasts - found in the inner layer of the periosteum and in the endosteum. These cells produce collagen and ultimately bone.

Osteoclasts - Very large multinucleated cells. Function in reabsorption of bone. May arise from the fusion of WBC’s

An osteoclast seen in a sample of dog bone.

Bone Matrix• The matrix of bone

consists of inorganic salt crystals on a protein matrix called an osteoid.

• Calcium salts are 50% of the dry weight and give bone its characteristic hardness.

• Main compound in bone is Ca3(PO4)2.

• This is distributed evenly along collagen fibers.

• Bone matrix also contains carbonate and citrate ions with Na, Mg and K.

• F, Rn, Pb, and Sr are also found in the matrix.

• Radioactive isotope of Sr can become concentrated in bone which can lead to osteogenic sarcoma or bone cancer

Collagen• Collagen is the

major part of the organic matrix of bone.

• It gives bone properties of toughness and tensile strength.

• Baked bone cracks, vinegar bone is flexible

• The osteoblasts produce collagen.

• Collagen has active sites that catalyze the precipitation of Ca and PO4 from the tissue fluids.

Bone Formation

• Bones grow in the developing human through two methods.

• Intramembranous - bones of the skull, clavicle and lower jaw.

• Endochondral - bones of the arms and legs.

• In both methods connective tissue is replaced by bone as the person ages.

• The picture shows the epiphyseal plates of a young athlete with an ACL injury.

Tendons• Composed of dense regular

connective tissue in a large number of parallel collagen bundles.

• Function is attaching muscles to bone or cartilage.

• As bones grow it is necessary for attachment points to move. How this is done is not understood.

• Tendons can be many different shapes.

• They are protected from each other and bones by a bursa or a tendon sheath which is filled with a lubricating fluid.

• Through repetitive use this sheath can become swollen and painful.

• In severe cases surgery to cut the sheath to make it larger helps to reduce the pain and allow movement again.

Ligaments• Similar to tendons.• Connect bones to

bones.• Composition is

similar to tendons. (Collagen fibers)

• Exceptions to this include the ligaments of the vertebral column which are composed primarily of elastin.

• Elastin stretches upon pulling and contracts back to its original shape when relaxed.

• Some ligaments associated with synovial joints are actually part of the fibrous wall of the joint capsule.

• The collateral ligaments of the knee are an example of this.

Osteoporosis• Osteoporosis is a condition that causes bones to become more porous, which gradually makes them weaker and more brittle.

• "Osteo" means bone, and "porosis" means porous.

• The bones do not have enough solid calcium and phosphorus, and steadily lose their supporting protein framework.

• They become thinner and more fragile than normal.

• Break more easily, particularly the spine, hip, and wrist

Osteoporosis cont.• To maintain bone

density, the body needs Ca and P.

• The body must also produce the proper amounts of several hormones, including estrogen in women and testosterone in men.

• An adequate supply of vitamin D is also needed to absorb calcium from food and incorporate it into bones.

• After age 30, bones slowly decrease in density.

• If the body cannot regulate the mineral content of bones, they become more fragile. The result is osteoporosis.

Osteoporosis factoids

• Osteoporosis affects over 25 million people each year.

• 80 percent are women. • 80 percent of women

over age 65 have osteoporosis.

• Osteoporosis is responsible for 1.5 million fractures each year and costs $15 billion for fracture care. Fractures do heal with appropriate measures

• After menopause, women lose about one to two percent of their bone density each year.

• 1.5 million men also have osteoporosis, and another 3.5 million men are at high risk.

• By the age of 80, nearly half of all women show, on an X-ray, that they have had a fracture of their spine. Yet many cannot recall any injury or incident that would have caused the fracture.

• osteoporosis

X-ray of hip fracture

15-20% of the elderly die within 15 months

after a broken hip

Hip Fracture repairThis hip fracture was surgically repaired with a prosthetic pin, shown above in

this x-ray image

Rickets• Children with vitamin

D deficiency are unable to absorb calcium and phosphate from the digestive tract.

• The bones become progressively weaker over time.

• If the condition persists blood calcium levels drop so low that the person develops tetanic respiratory spasm which leads to death.

• A diet rich in calcium and phosphorus and vitamin D reverses this situation.

Knock knee deformity in Rickets (genu valgum)

Wind Swept deformity of Rickets

Before treatment and 2 years after treatment with Calcium

Resurgence of Rickets in the US

• Long commutes, smog and day care are contributing to the resurgence of childhood rickets.

• Not many foods are rich in vitamin D.• The primary source of the nutrient is

milk, because the dairy industry began adding the vitamin in the 1930s to prevent the disease.

• Other vitamin D sources include sunshine and cod liver oil. Sunlight stimulates the body to produce vitamin D.

• Breast milk does not contain vitamin D. • Many parents are choosing soy and rice-

based milk for their infants. Those products lack vitamin D, and parents might need to supplement their infant's diet with vitamin D to stave off rickets.

• Children of vegan parents are very much at risk of rickets if their parents do not supplement their diet with the vitamin.

• Low melanin levels allow fair-skinned people to better absorb vitamin D from the sun.

• People of African and Asian descent may have more melanin in their skin, which offers protection from skin cancer but inhibits the ability to absorb the vitamin.

• The rickets increase is most significant among black infants who were breast-fed

Osteomyelitis• Osteomyelitis is a serious bacterial or fungal infection of the bone marrow.

• It can begin as a simple infection from a fracture or injury and, if not treated, can become chronic.

• Mickey Mantle suffered from chronic osteomyelitis.

• He had to stop playing in August of 1961 because of this condition.

• At the time he had 54 home runs and was competing with Roger Maris for the home run crown and Babe Ruth’s record of 60 home runs.

• Now, this condition is easily treated with modern antibiotics.

Bone Types

• There are four main types of bone: long , short, flat and irregular bones.

• Most people have around 206 bones in their skeleton.

• Flat bones include the bones of the cranium, sternum, scapula and ribs.

• Irregular bones include certain facial bones and the bones of the vertebrae.

• Sesamoid bones develop within a tendon. The patella is a sesamoid bone.

• Wormian bones are small islets of bone that can form within the joints between cranial bones.

Bone Surface features

• Articular Surfaces - where one bone forms a joint with another.

• Facets - very small areas where one bone meets another or a tendon or ligament is attached.

• Condyle - surface shaped like a knuckle

• Foramen - an opening on the surface of a bone.

• Meatus - a tubelike passageway in a bone.

• Process - a large distinct projection on the surface of a bone.

• Tubercles - large rounded projections on a bone.

Hyoid bone• The hyoid bone is a bone in the human neck.

• It is not articulated to any other bone; it is supported by the muscles of the neck and in turn supports the root of the tongue.

• Its name is derived from the Greek word hyoeides meaning "shaped like the letter upsilon" (u).

• The hyoid bone is shaped like a horseshoe, and is suspended from the tips of the styloid processes of the temporal bones by the stylohyoid ligaments.

Vertebral Column

• Supports the head.• Houses and protects

the spinal cord.• Articulates with the

ribs.• Attachment point for

many of the muscles of the back.

• Allows for movement in all directions.

• Movement between any two vertebrae is not great, but the sum of all the small movements is great.

• Typically 33 vertebrae.

Intervertebral Foramina

• These are openings that allow nerves to pass out from the spinal cord and go to parts of the body.

• The diagram shows one of the many intervertebral foramens of the vertebrae.

• Pressure on these nerves because of damage to a disk can result in severe pain.

Intervertebral disks• The intervertebral discs are fibrocartilaginous cushions serving as the spine's shock absorbing system.

• It is the discs in the lumbar area that can most easily move out of place, fray or burst.

• This is what causes most of the low back problems that people experience.

Disc structure

• The discs are structured like tires with a tough outer part and an inner softer part.

• The inner part of the disc is composed of a semiliquid core.

• These discs function in absorbing all kinds of gravitational and twisting forces applied to the back.

• They can wear out, slip, burst and cause problems.

Herniated Discs

• In herniated discs a trauma has made the inner components of the disc squeeze out through a tear or rupture of the outer layer.

• When the disc has been forced out, it puts pressure on part of the spine that feeds to a nerve.

• The results can range from sharp, shooting pains to dull pains.

• About half the time ruptured discs will repair themselves and the extruded material will be reabsorbed.

• It appears that macrophages from affected blood vessels are the agents in disc reabsorption and repair.

• herniated disc story

Cervical Disc herniation

• This MRI scan of the cervical spine shows a typical disc protrusion between the 5th and 6th cervical vertebra compressing the spinal cord.

• This compression could cause severe pain, numbness and tingling down one of the arms.

• If initial treatments do not work the doctor may decide to remove the disc.

• One of the ways to do this and stabilize the area is to fuse the two affected vertebrae with a bone graft.

Cervical vertebrae fusion surgery

• The vertebrae is approached from the front of the throat to one side of the adams apple.

• The damaged disc is removed and replaced with bone grafts from the patient or a cadaver’s iliac crest.

• A plate is used to stabilize the area and allow for healing to occur.

• New bone tissue will grow through the bone graft fusing the two affected vertebrae together.

Cervical Fusion Surgery

• After the surgery the patient will have several stitches on the front of the throat.

• The patient will need to wear a neck brace for up to 6 weeks after the surgery.

• If only two vertebrae are involved the patient most likely will not notice any loss of movement.

• cervical fusion patient story

Atlas and Axis Vertebrae

• The atlas is the first cervical vertebrae.

• It supports the skull.• The body of the atlas is

fused to the axis.• Together these bones

rotate on the 3rd cervical vertebrae to allow the head to pivot.

• These are the most unique vertebrae of the body.

• They also serve as places for muscle and ligament attachments to help hold the neck upright.

Sternum• Consists of three parts,

manubrium, body and Xiphoid process.

• Manubrium has facets for the clavicle and the first rib.

• The body usually has three ridges which run across it.

• The xiphoid process is cartilaginous when a person is a child and it frequently ossifies in the adult.

• Several muscles, including the rectus abdominis have fibers which attach to the xiphoid process.

Ribs and Costal cartilage• There are 12 ribs on each side of the body.

• Each rib connects to a thoracic vertebrae.

• The top seven are true ribs which connect directly to the costal cartilage and the sternum.

• The remaining five are false ribs. Three of them connect the costal cartilage of the 7th rib.

• The remaining two ribs are floating ribs with no connection to the costal cartilage

Pectoral Girdle

• The clavicle is the only bone that articulates the pectoral girdle with the axial skeleton.

• The four regions arm, forearm, wrist and hand.

• The humerus is the single bone of the arm.

Clavicle and Scapula

• The only bone that articulates the pectoral girdle with the axial skeleton is the clavicle.

• The Scapula lies over the second through seventh ribs. It articulates with the humerus and the clavicle.

• The pectoral girdle is relatively loosely connected to the axial skeleton and this gives the arms a great degree of movement and flexibility.

Upper limb

• Bones include the humerus, radius, ulna, carpals, metacarpals and phalanges.

• The humerus is the single bone of the arm.

• The radius and ulna are the bones of the forearm.

• The funny bone is actually the ulnar nerve being bumped against the humerus near the elbow.

The Funny Bone

• The ulnar nerve lies in a groove between the Trochlea and the medial epicondyle of the humerus.

• The nerve is relatively unprotected.

• A blow here may produce a tingling or numbing sensation throughout the forearm and hand.

Radial head and tuberosity

• Radial tuberosity is a projection on the radius near the elbow.

• It is the place where the biceps brachii is attached.

• Radial head is the disc shaped surface that articulates the radius with the ulna and the humerus.

Olecranon Process

• This large process forms the elbow.

• Some fibers from the triceps brachii muscle attach here.

Dislocated Elbow

• 1965, July - Harmon Killebrew dislocates his left elbow in the All-star game.

• He did not return to the line-up until August of that year.

This an X-ray of a dislocated elbow. There is danger of vessel and nerve damage.

Patients usually have a full recovery.

• The hand is divided into three regions;

• bones of the wrist or carpal bones,

• Bones of the palm or metacarpals,

• Bones of the digits, or phalanges

Pelvic girdle

• The three main bones of the pelvic girdle are the ilium, ischium and the pubis.

• These three bones combine to form the coxal or innominate bone for each half of the hip.

• The coxal bones articulate with the sacrum at the sacroiliac joint.

• The ischium has a tuberosity that we sit on. (ischial tuberosity)

Patella

• The Patella is a bone that develops within the tendon of the quadriceps femoris muscle.

• The bone sometimes does not completely develop or their can be two pieces.

• The patella has quite a bit of lateral movement.

• It has very little up and down movement.

• Primary function of this bone is to improve the lever action of the quadriceps muscle.

Patella dislocations• There are two kinds of patellar

instability.• Post injury:• Most dislocations heal with a

period of rest followed by physiotherapy.

• Developmental Instability• The patella can be too small or

too high; • The groove in the trochlea can

be too shallow or even non-existent;

• There may be tightness in the soft tissues on the lateral (outer) side of the knee.

• Surgery may be required to correct these situations.

patella arthroscopy`

Femur

• This is the heaviest and the longest bone of the body.

• The greater and lesser trochanter are attachment points for various muscles.

• People can only palpate this bone near the hip and knee.

• Breaking this bone usually requires traction to help it set.

This person completely fractured their femur.The doctors have placed a rod down the middle of the femur.

There is a rod in the tibia to aid in the traction process

Tibia and Fibula

• These are the two bones of the leg.

• The tibia is the weight bearing bone.

• The distal end of the tibia forms the inside part of the ankle.

• The fibula functions as a place for muscle attachment.

• The distal end of the fibula forms the lateral part of the ankle.

Tibia and Fibula fractures

Foot and Ankle structure

Ankle Sprain

• An ankle sprain is when the ankle joint is forced out of position causing tearing of some of the ligaments that stabilize the ankle joint.

• Ankle sprains are placed in three groups (I, II and III) with III being the most severe.

• Grade III can require several weeks to heal and occasionally surgery is required.

Plantar Fasciitis• Plantar fasciitis is the #1 most common foot problem.

• It is caused by activity, overuse and aging.

• Plantar fasciitis is an inflammation due to repeated overstretching of the plantar fascia ligament (fat pad of the foot), usually at the point where the fascia is attached to the heel bone.

• This condition can also occur at the front of the foot. The pain usually decreases after walking.

• Contributing factors are: flat (pronated feet)

• high arches (supinated feet) • increasing age • sudden weight increase • sudden increase in activity

level • running in sand • hereditary factors

Heel Spurs• A Heel Spur is a piece of calcium or bone that sticks out from the bottom of the heel bone, and lies within the fibers of the plantar fascia.

• When walking, the spur digs into the plantar fascia and causes small micro-tears in the plantar fascia.

• This produces inflammation and pain in the heel, which at times may radiate into the arch.

• Jenny Finch

Joints• Joints are places

where one bone meets another or meets cartilage.

• Growth is a primary function of the joints of the cranium.

• Fontanels or soft spots permit the birth of the baby and allow for the expansion of the skull.

• Most other joints are sites that provide for movement of the body.

Bursae

• Bursae are fibrous sacs that encase a synovial joint and produce synovial fluid.

• They cushion and reduce friction between tissues.

• The prepatellar bursa, seen in this diagram, serves to cushion the skin from the forces that develop when the knee joint is flexed.

• Bursa of the knee and the shoulder are connected with the joint cavity itself.

Synovial Tendon Sheaths

• These are bursal sacs that surround certain tendons.

• They help to reduce friction in places where there are a lot tendons close together

• These sheaths are common in the wrist.

• From repetitive stress and injury these sheaths can become inflamed.

• This can result in great pain when movement is attempted.

Fibrous Joints• Do not have a joint

cavity.• Bones are joined by

fibrous connective tissue.

• The sutures of the skull are an example of a non-moveable fibrous joint.

• The teeth are an example of another fibrous joint. They are fixed in their sockets by collagenous fibers (Sharpey’s fibers) that penetrate the bone of the jaw.

Cartilaginous Joints

• Also lack joint cavities.

• The bones are held together by cartilage.

• They do permit a small amount of movement.

• The pubic symphysis and the vertebrae joints are examples of cartilaginous joints.

• The pubic symphysis naturally widens - to as much as 1 cm - during pregnancy and childbirth.

• It usually closes up after the woman has given birth, but in some cases, it widens too much and the pelvis becomes unstable, causing the woman pain.

Synovial Joints• Bones are bound

together in a fibrous capsule.

• Ligaments help to stabilize these freely movable joints.

• The synovial cavity surrounds the ends of the the bones making up this joint.

• Bone ends are covered with articular cartilage which is hard and smooth.

• This articular cartilage helps to reduce friction.

Plane or gliding joints• Synovial joints

that are found between the metatarsals and metacarpals.

• Slight gliding motions in a single plane but at right angles to each other are permitted.

• Movement in other directions is resisted by the presence of ligaments and bones.

Hinge Joints.

• Motion is usually restricted to flexion and extension.

• The elbow, fingers and the ankle are great examples of hinge joints.

• The elbow can be replaced, like the knee, if it is severely arthritic.

Pivot Joints

• Permit rotation about a single axis.

• Usually has a ring-like and a pivot component.

• Includes the atlas-axis of the neck and the rotation of the radius on the ulna.

• These joints allow you to look left and right and the pronate (rotate the palm down) and suppinate (rotate the palm up)

Condylar Joints

• This is the characteristic joint of the knee and the jaw.

• These joints permit flexion and extension primarily.

• There is also some degree of rotation possible.

• The jaw (the temporomandibular joint) has the same characteristics.

Lever classes of some of the joints.Most joints are 3rd class levers. This permits great range

of motion.

Anterior Cruciate Ligament • The anterior cruciate

ligament (ACL) stabilizes the knee.

• ACL injuries occur most often during athletic activities.

• When the ACL is injured, it may require surgical repair to restore the knee's stability and normal function.

• ACL reconstruction has become a common knee procedure.

• New technologies and surgical techniques combined with physical therapy allow a full return to normal activity

ACL damage• The demands placed on the

knee sometime exceed its limits.

• In fact, the knee is the most commonly injured area for athletes.

• One common cause of ACL tears is rotating the leg inward while the rest of the body is turning outward.

• ACL injuries also may occur when the knee is turned outward while the upper leg is turning inward.

• This is most commonly seen in athletes as they change direction.

ACL repair

• The tendon ends that are left cannot be sewed back together.

• The middle third of the patellar tendon is used as a substitute graft.

• Sometimes a part of one of the hamstring tendons is used instead of the patellar tendon.

• A new technique is to use cadaver tendons.

ACL reconstruction

• After the arthroscopic evaluation, two small tunnels will be made.

• The first tunnel is placed through the tibia, and the second will be in the femur.

• The graft is pulled into place through the tunnels in the exact position of your ACL.

• After the graft has been inserted into the new tunnels, it is fixed in place.

• This will secure the graft until complete healing can take place

• ACL animation

• ACL repair surgery

Arthroscopic Knee Surgery• Arthroscopic Knee surgery is

performed through small incisions in the skin to repair injuries to tissues within the knee joint area.

• The surgery is conducted with the aid of an arthroscope, which is a very small instrument guided by a lighted scope attached to a television monitor.

• Other instruments are inserted through three incisions around the knee.

• Arthroscopic surgeries often are minor procedures such as flushing or smoothing out bone surfaces or tissue fragments (lavage and debridement) associated with osteoarthritis.

• Arthroscopy can include more complex procedures like the realignment of a dislocated knee and ligament grafting surgeries.

• knee arthroscopy

Saddle joint

• The saddle joint is biaxial and is seen in the carpometacarpal joint of the thumb.

• This joint allows the thumb to oppose the other fingers of the hand.

Spheroid or Ball and Socket Joint• The hip and the shoulder

are examples of ball and socket joints.

• This type of joint permits movement along three separate axes.

• This includes flexion-extension, adduction-abduction and rotation.

• The head of the femur fits into a cuplike cavity in the hipbone called acetabulum.

• The hip is stabilized by ligaments which attache the ball to the acetabulum.

• The ball is covered with a glassy coating of hyaline cartilage.

Hip Replacement Surgery.• Total hip Replacement

Surgery is offered to people whose hips have been damaged by arthritis and injury.

• It is a major operation with a lengthy recovery.

• Patients work hard on recovering range of motion and muscle strength.

• A major problem is the loss of bone mass in the diaphysis around the artificial post.

• This can necessitate another operation to replace the now loose artificial implant.

Rotator Cuff

• The rotator cuff connects the humerus to the scapula.

• It is formed by the tendons of four separate muscles: the supraspinatus, infraspinatus, teres minor, and subscapularis.

• These muscles raise and rotate the arm by pulling on the tendons.

• As the arm is raised, the rotator cuff keeps the humerus bone tightly in the socket of the scapula.

• The acromion and coracoid process are both protrusions of the scapula bone.

Osteoarthritis

• Arthritis is an inflammation of the joint.

• The most common form of arthritis is osteoarthritis.

• Affects more than 40 million people.

• It is a degenerative disease, where the articular cartilage deteriorates.

• New bone spurs can form, break-off and become trapped in the joint.

Knee Replacement• Total Knee Replacement

is done when a persons knee has been severely damaged by injury or disease.

• The goal is to reduce pain, increase movement and improve the quality of life.

• The diseased parts of the knee are surgically removed and replaced with metal and polyethylene.

• Plastic bone cement is used to lock the prosthesis into place.

• Running, contact sports and heavy lifting are not possible after this surgery.

Rheumatoid Arthritis• This is a chronic,

generalized inflammation of many body tissues that primarily affects the joints.

• It is an autoimmune disease, that is the body is attacking its own tissues.

• The body attacks the synovial membrane in the joints of the fingers or toes.

• The membrane is gradually destroyed to be replaced by connective tissue.

• Eventually the growth of this fibrous tissue causes the bone ends to meet and the joint disappears.

• It is treated with gold salts, rest, heat and often goes into spontaneous remission

Cleft Palate and Lip• Affects about 1 in 700 babies.• During the early stages of

pregnancy, the upper lip and palate develop from tissues lying on either side of the tongue.

• When the tissues that form the upper lip do not join in the middle of the face, a gap occurs in the lip.

• Usually, a single gap occurs below one or other nostril (unilateral cleft lip).

• Sometimes there are two gaps in the upper lip, each below a nostril (bilateral cleft lip)

• Some evidence suggests there may be a genetic factor, as cleft lip and palate can run in families.

• It is thought, however, that certain types of drugs may increase the risk.

Cleft Palate Problems and Solutions

• The most immediate problem caused by a cleft lip or palate is difficulty with feeding.

• Many babies with a cleft lip can breastfeed. However, some have difficulty in forming a vacuum in order to suck properly.

• Cleft Palate can affect speech, hearing and the proper growth of the jaw and teeth.

• Surgery is the most common treatment for Cleft Palate.

• Surgery for the lip is first done when the baby is about 3 months old.

• Surgery to close the gap in the palate is usually done when the baby is 6 months old.

• As the child grows older further surgery may be needed to improve the appearance of the lip and nose and the function of the palate.

• If there is a gap in the gum, a bone graft may be used to fill it.

Bone Fracture Healing

• There are three major phases of fracture healing.

• 1. Reactive Phase• 2. Reparative Phase• 3. Remodeling

Phase

Reactive phase

• The first change seen is the presence of blood cells within the tissues which are adjacent to the injury site.

• Soon after fracture, the blood vessels constrict, stopping any further bleeding.

• Within a few hours after fracture, the extravascular blood cells, known as a "hematoma", form a blood clot.

• All of the cells within the blood clot degenerate and die.

• Within this same area, the fibroblasts survive and replicate.

• They form a loose aggregate of cells, interspersed with small blood vessels, known as granulation tissue