Knee Osteoarthritis

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Search Strategy

Databases used: Pubmed, Web of knowledge, American college of rheumatology.

Keywords used: osteoarthritis, knee, epidemiology, etiology, treatment, definition, exercises, surgery, condition (or a combination of these words).

Definition/Description

Knee osteoarthritis is the occurrence of osteoarthritis(A) (OA) in the knee joint. Osteoarthritis has many definitions, but Kuttner et al . defined it as follows: “Osteoarthritis, also known as degenerative arthritis or degenerative joint disease, is a group of overlapping distinct diseases, which may have different etiologies but with similar biologic, morphologic, and clinical outcomes.”12
In other words osteoarthritis involves the degradation of joints, including articular cartilage and subchondral bone. But also ligaments, the capsule and the synovial membrane degenerate. This will eventually lead to pain and loss of function.11
Osteoarthritis is the most common disease of joints adults suffer from worldwide. The name ‘osteoarthritis’, a Greek word, can be divided in ‘osteo’, ‘arthro’ and ‘it is’. If we translate the word we become ‘of the bone’, ‘joint’ and ‘inflammation’.10 Thus, simply put, we can say that osteoarthritis is an inflammation of the bone and joint. Besides knee osteoarthritis, which is the most common, you also have hand and hip osteoarthritis.

Clinically Relevant Anatomy

The knee (art. genus) is a synovial joint, which consists of 3 articulations. The primary joint, art. tibiofibularis, is located between the convex femoral condyles and the concave tibial condyles.[13] There is also the art. patellofemoralis between the femur and the patella and the art. tibiofibularis located between the tibia and fibula. OA can only occur in the two primary articulations of the knee, namely the tibiofemoral and patellofemoral joint, because they have to sustain more motion than the art. tibiofibularis.[12]

“The pathogenesis of knee OA have been linked to biomechanical and biochemical changes in the cartilage of the knee joint.” (Kirstin Uth et al, 2014)[16] The cartilage ensures that the bone surfaces can move painless and with low friction to each other. In OA, the cartilage decreases in thickness and quality, it becomes thinner and softer, cracks may occur and it will eventually crumble off. Cartilage that has been damaged, cannot recover. Finally the cartilage will disappear. The bone surfaces can also be affected, the bone will expand and spurs (osteophytes) will develop.[17] [18]

Not only the cartilage can be affected, there can also occur laxity of the ligaments and muscle atrophy.

Characteristics/Clinical Presentation

The physical findings of and OA knee include:

• Bony enlargement
• Crepitus
• Decreased range of motion (ROM)
• Joint-line tenderness
• Pain on passive ROM

Diagnostic Procedures

Symptoms:

Primary:
- Pain
- Stiffness, particularly in the morning
- Decrease in the abilities of daily functioning

Secondary:
- Loss of mobility in the affected joint
- Decrease in muscle power
- Instability of the joint
- Crepitations

X-ray: The basic X-ray is used to research breakdown of cartilage, narrowing of joint space, forming of bone spurs and to exclude other causes of pain in the affected joint.

Arthrocentesis: This is a procedure which can be performed at the doctor’s office. A sterile needle is used to take samples of joint fluid which can then be examined for cartilage fragments, infection or gout.

Arthroscopy: is a surgical technique where a camera is inserted in the affected joint to obtain visual information about the damage caused to the joint by the osteoarthritis.

The European League Against Rheumatism developed diagnostic criteria for diagnosing knee osteoarthritis. The most important factors are shown in the following figure.

File:Risc factors.jpg

EULAR evidence-based recommendations for the diagnosis of knee osteoarthritis

Outcome Measures

add links to outcome measures here (also see Outcome Measures Database)

Examination

If a patient is referred to you by a doctor, it is most likely he performed a medical examination. It is imperative to look at his/her findings when examinating the patient.
- Inspection:
mind the position of the joints when in rest and how the patient moves. This can be accomplished by making the patient perform simulations of daily activities such as getting up from and down on a chair, stair climbing, etc.

- Palpation:
mind: swelling, temperature differences, muscle tonus. Also be wary of possible bone spurs (osteocytes) that have formed on the edge of the joint. These osteocytes are a serious indication towards osteoarthritis.

- Examination of basic functions:
Testing of muscle power, coordination, mobility, balance and also stability of the joint. These factors can be tested by active test like standing on one leg and passive manual tests. When testing stability of the joint muscle strength and proprioception are of significant importance.

Medical Management

- Anti-inflammatory medication to counter periodic inflammation
- Surgical replacement of knee joint when damage to natural structures is too grave.

Physical Therapy Management

Exercise	Has proved to be effective as pain management and improving of physical functioning on short term. However these exercises have to take place under supervision of a health care professional such as a physiotherapist. When properly instructed these exercises can be performed at home. However research has shown that group exercise combined with home exercise is more effective than home exercise alone. ,
Hydrotherapy	Is recommended in international guidelines. Despite contradictory evidence hydrotherapy can be useful in cases where pain is too grave to exercise on dry land. It can be a good preparation of exercise on dry land. Osteoarthritis usually affects the weight-bearing joints. Some of the above symptoms like muscle weakness will be present in most patients. The strength of muscles around the affected joints can be built up by graduated exercises making use of buoyancy and floats (in the later stage of the treatment). Range of motion can also be maintained and increased using the freedom of movement offered by the water with the support given by the buoyancy. Functional difficulties of osteoarthritis patients are generally concerned with walking and climbing stairs and much can be done to re-educate such patients in the pool. Many patients are more mobile in water than on land and this gives them greater confidence and a sense of achievement. Other studies show that aquatic exercise (Aquatherapy) has some short-term beneficial effects. They established that there is a positive effect on both mixed knee and hip Osteoarthritis and on knee Osteoarthritis alone at the end of an aquatic training program. Also no long-term effects have been found. Aquatic exercise may therefore be considered as the first part of an exercise therapy program tot get particularly disabled patients introduced to training.
Manual actions: Achieving a passive motion in the joint	Has proven effective to locate and eliminate factors like pain and joint immobility. However, it is only effective when combined with active exercise. This progress can enable further or advanced exercises.
Massage	Is not effective in the case of osteoarthritis.
Thermotherapy	Can be used to warm up of tissue (for example very stiff joints) before exercise.
Electrotherapy	For example electro stimulation in improving quadriceps muscle strength is not proven effective.
Ultrasound	Is not advised in the treatment of knee osteoarthritis.
External Support Devices	Braces: - total knee braces when being diagnosed with total knee   osteoarthritis - lateral elevated orthopedic sole when being diagnosed with   medial compartment knee osteoarthritis. Taping: Has proven slightly effective in decreasing pain in patients with patellofemoral osteoarthritis.
Post-operative Exercise	Is very much recommended. Exercises to improve the function of the new joint and muscle strengthening are most effective.

Key Research

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Resources

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Clinical Bottom Line

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Recent Related Research (from Pubmed)

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