OSTEOARTHRITIS
i
,A. Definition
Osteoarthritis according to the American College of Rheumatology is a
heterogeneous group of conditions that lead to joint signs and
symptoms.Osteoarthritis (OA) is the most common form of arthritis and one of
the leading causes of disability. The knee is the largest synovial joint in humans,
consisting of bony structures (distal femur, proximal tibia, and patella), cartilage
(meniscus and hyaline cartilage), ligaments and synovial membrane. The latter is
responsible for the production of synovial fluid, which provides lubrication and
nutrition to the avascular cartilage. Unfortunately, given the high usage and stress
of this joint, it is a frequent site for painful conditions including OA. 7 It is also
recognized that cartilage tissue is not the only tissue involved. Due to its lack of
blood vessels and innervation, cartilage by itself is incapable of producing
inflammation or pain at least in the early stages of the disease. Therefore, The
main source of pain comes from changes in the noncartilaginous components of
the joint, such as the joint capsule, synovium, subchondral bone, ligaments, and
periarticular muscles. As the disease progresses, these structures are affected and
changes including bone remodeling, osteophyte formation, periarticular muscle
wasting, ligament laxity, and synovial effusion may become evident.This disorder
is a degenerative process in the joints that affects the knee joint.
B. Knee Anatomy
1. Knee Joint Bones
The knee joint is formed by several bones, namely:
a. Femur
The femur is the longest tubular bone. The framework at the base
of which is connected to the acetabulum forms a joint head called the
head of the femur. Above and below the columna femoris there are
spurs called the trochanter major and trochanter minor, at the ends
forming the knee joint, there are two protrusions called the condylus
medianus and condylus lateralis. Between these two condyles there is
an indentation where the kneecap bone (patella) is located which is
called the condylar fossa.
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, b. Tibial Bone
The tibia bone is a smaller bone, attached to the fibular bone at the
base, forming a joint with the peduncle of the foot at the end and there
is a taju called the median malleolus bone.
c. Fibula Bone
The fibula is the largest tubular bone after the femur which forms
the knee joint with the femur at the end having a bulge called the
lateral malleolus or the outer ankle.
d. Patellar Bone
In flexion and extension the patella moves on the femur. The
distance between the patella and the tibia when movement occurs is
fixed and what changes is only the distance between the patella and the
femur. The function of the patella besides acting as an attachment to
the muscles or tendons is as a lever for the knee joint. Under
conditions of 90 degrees the position of the patella between the two
condyles of the femur and during extension the patella lies on the
anterior surface of the femur.
Figure 1. Anatomy of a normal knee joint 3
2. Muscle
a. Knee Extensor Muscles (Quadriceps Femoris)
2
i
,A. Definition
Osteoarthritis according to the American College of Rheumatology is a
heterogeneous group of conditions that lead to joint signs and
symptoms.Osteoarthritis (OA) is the most common form of arthritis and one of
the leading causes of disability. The knee is the largest synovial joint in humans,
consisting of bony structures (distal femur, proximal tibia, and patella), cartilage
(meniscus and hyaline cartilage), ligaments and synovial membrane. The latter is
responsible for the production of synovial fluid, which provides lubrication and
nutrition to the avascular cartilage. Unfortunately, given the high usage and stress
of this joint, it is a frequent site for painful conditions including OA. 7 It is also
recognized that cartilage tissue is not the only tissue involved. Due to its lack of
blood vessels and innervation, cartilage by itself is incapable of producing
inflammation or pain at least in the early stages of the disease. Therefore, The
main source of pain comes from changes in the noncartilaginous components of
the joint, such as the joint capsule, synovium, subchondral bone, ligaments, and
periarticular muscles. As the disease progresses, these structures are affected and
changes including bone remodeling, osteophyte formation, periarticular muscle
wasting, ligament laxity, and synovial effusion may become evident.This disorder
is a degenerative process in the joints that affects the knee joint.
B. Knee Anatomy
1. Knee Joint Bones
The knee joint is formed by several bones, namely:
a. Femur
The femur is the longest tubular bone. The framework at the base
of which is connected to the acetabulum forms a joint head called the
head of the femur. Above and below the columna femoris there are
spurs called the trochanter major and trochanter minor, at the ends
forming the knee joint, there are two protrusions called the condylus
medianus and condylus lateralis. Between these two condyles there is
an indentation where the kneecap bone (patella) is located which is
called the condylar fossa.
1
, b. Tibial Bone
The tibia bone is a smaller bone, attached to the fibular bone at the
base, forming a joint with the peduncle of the foot at the end and there
is a taju called the median malleolus bone.
c. Fibula Bone
The fibula is the largest tubular bone after the femur which forms
the knee joint with the femur at the end having a bulge called the
lateral malleolus or the outer ankle.
d. Patellar Bone
In flexion and extension the patella moves on the femur. The
distance between the patella and the tibia when movement occurs is
fixed and what changes is only the distance between the patella and the
femur. The function of the patella besides acting as an attachment to
the muscles or tendons is as a lever for the knee joint. Under
conditions of 90 degrees the position of the patella between the two
condyles of the femur and during extension the patella lies on the
anterior surface of the femur.
Figure 1. Anatomy of a normal knee joint 3
2. Muscle
a. Knee Extensor Muscles (Quadriceps Femoris)
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