Prior to 1986, the definition for osteoarthritis was: "Osteoarthritis, or degenerative arthritis, is a heterogeneous group of conditions that lead to joint symptoms and signs which are associated with degeneration of articular cartilage, in addition to related changes in the underlying bone and at the joint margins."[1] Osteoarthritis has known many other definitions by time until a more recent definition was issued by Kuttner et al[2], in 1994 and reads as follows: "Osteoarthritis is a group of overlapping distinct diseases, which may have different etiologies but with similar biologic, morphologic, and clinical outcomes. The disease processes not only affect the articular cartilage, but involve the entire joint, including the subchondral bone, ligaments, capsule, synovial membrane, and periarticular muscles. Ultimately, the articular cartilage degenerates with fibrillation, fissures, ulceration, and full thickness loss of the joint surface."

Epidemiology /Etiology


As highlighted by Peyron[3], one adult on three has osteoarthritis and above 55 years, this disease has a prevalence of 4 times more than the total population. Professionals in collaboration[4] mentioned that people from the United States and black people from Jamaica and Africa has the highest prevalence. Further on, woman has a higher prevalence as well. Race- and gender differences are more clearly than climatic differences.

Allander et al.[5] approved that age has an influence on the severity of osteoarthritis at the level of hands and feet. This proves the relation between age and gender with osteoarthritis. Further on, research from Kelsey et al.[6] proved that arthritis and musculoskeletal diseases are the most common chronic diseases and causes of physical disability in the United States.


We can make out two forms of osteoarthritis:[4]

Primary osteoarthritis

This is the form of osteoarthritis in which you don't know what could trigger the disease. You can't infer anything from history, nor clinical or radiographic examination.

Secondary osteoarthritis

This last form can be caused by trauma, metabolic disease, congenital malformations, premature menopause, etc. Sometimes, it can happen that a patient is suffering from secondary osteoarthritis before the age of 40.

Characteristics/Clinical presentation

Clinical signs depend mainly to the affected joint but usually, they show some common characteristics. They're mainly local. Symptoms are[4]:

  • Pain:
    This is a 'mechanical' type of pain which is generated by mobilization, increases with fatigue and decreases with rest. Pain occurs in the morning or after a period of inactivity. Mostly, there's no overnight pain. The intensity of pain is variable. Sometimes it's dull and tolerable, other times it's very heavy with short peaks. It can be stimulated by cold, trauma and fatigue.
    This pain occurs at the level of the subchondral bone and in capsuloligamentar and muscular structures.
  • Limitation in movement (loss of ROM):
    Limitation in movements expires insidious, progressive and  will be noticed after several years. This limitation is mainly related to the blocking of voluntary muscle functioning and the reflex contracture. It's also the result of changes in the articular spaces, with incongruent joint surfaces. Some patients complain about stiffness in the morning, which holds on for a longer period but is less severe than the morning stiffness from rheumatoid arthritis or ankylosing spondylitis. In most of the patients the limitation in movement is progressive. The severity increases with time and is accompanied with the joint deformities and wear of the cartilage.
  • Sounds: 
    The sounds you can hear are cracking, scraping and sounds from crepitation. They're generated by mobilization of the joint. You can even hear them when you palpate the joint. Irregularities in the articulating joint surfaces and poor quality of the remaining cartilage is very likely to be the cause.
  • Difficult and painful mobilization:
    It's important to differentiate between total blocking and limited mobility, due to immobilization for a longer period. Total blocking is caused by the presence of meniscus, unusual structures, etc.
  • Morphological deformities:
    The affected joint is only in a few cases red and feels warm. Normally, it has a normal color and temperature. The increase in volume is due to changes in ratio between the joint surfaces. There may also be moisture in the arthritic joint, caused by irritation, mechanical and/or biochemical phenomena at the synovial membrane.

There are no biological characteristics of osteoarthritis. There are no inflammatory signs nor immunological disorders or abnormalities of phosphocalium metabolism.

Differential diagnosis

Osteoarthritis is a degenerative process at the level of the cartilage and should be well distinguished from arthritis, where it’s about a synovial inflammatory process[4].

Abrasive, scraping sensations of the patella during mobilization of the knee joint can also occur in patients with Chondromalacia patellae, with preservation of the articular cartilage.

Diagnostic procedures

Osteoarthritis of the knee

The severity of osteoarthritis can be evaluated by radiography, according the Kellgren[7]. By this way, we can discriminate four degrees of severity in osteoarthritis:
Degree I: normal joint with a minimal osteophyte.
Degree II: Osteophytose on two points with minimal subchondral sclerosis, proper joint space and no deformity.
Degree III: Moderate osteophytose, early deformity of the bone endings and a joint space which narrows.
Degree IV: Large osteophytes, deformity of bone endings, narrowing joint space, sclerosis and cysts.

Outcome measures

Outcome Measures emphasizing Pain Component in Osteoarthritis

  • Hip Disability and Osteoarthritis Outcome Score[8]
  • Knee Injury and Osteoarthritis Outcome Score
  • Western Ontario and McMaster universities osteoarthritis index (WOMAC) WOMAC Osteoarthritis Index,
  • Algofunctional index (AFI)
  • Intermittent and constant osteoarthritis pain index(ICOAP)
  • West-Haven-Yale Multidimensional Pain Inventory (Assesses chronic pain in individuals and Recommended for use in conjunction with behavioral and psycho-physiological strategies)
  • Oxford Hip Scale (A 12 item subjective questionnaire to measure the outcome of total hip replacement)
  • Oxford Knee Score (Developed as an outcome measure to be used with patients having a total knee replacement).
  • McGill Pain Questionnaire Short-Form (The short-form McGill Pain Questionnaire was created to assess both the intensity and quality of pain)

Outcome Measures emphasizing Activities of Daily Living (ADL)Component in Osteoarthritis

  • Canadian Occupational Performance Measure (Assesses an individual’s perceived occupational performance in the areas of self-care, productivity, and leisure)
  • Medical Outcomes Study Short Form 36 (The SF-36 is a generic patient-reported outcome measure aimed at quantifying health status, and is often used as a measure of health-related quality of life)
  • WHO Quality of Life-BREF (WHOQOL-BREF) {Assesses quality of life (QOL) within the context of an individual's culture, value systems, personal goals, standards and concerns.}
  • Community Integration Questionnaire II (Like the original CIQ, the CIQ-2 is designed to assess Activities of Daily Living across several domains)
  • Quebec User Evaluation of Satisfaction with Assistive Technology (Evaluates a patient's satisfaction with various assistive technologies)
  • Physical Activity Scale for the Elderly (Measures the level of self-reported physical activity in individuals aged 65 years or older and is comprised of items regarding occupational, household, and leisure activities during the previous 7-day period)
  • Lower Extremity Functional Scale (Used to evaluate the impairment of a patient with lower extremity musculoskeletal condition or disorders. Can be used clinically to measure the patients’ initial function, ongoing progress, and outcome as well as to set functional goals.)
  • Keele Assessment of Participation (Intended to measure an individuals level of participation in various activities including work, education, social activities, and activities of daily living)

Physiotherapy management

OA causes reduced muscle strength (particularly in those muscles around the affect joint), decreased flexibility, weight gain, limitation in the ability to do ADL-activities and often compromised mobility. Increased physical and psychological function and an increased feeling of well-being are the main goals of an integrated exercise program. Increased joint motion, enhancing muscle strength, increased aerobic capacity and optimal body weight are immediate objectives.[9]

Basic physiotherapy[10](Not for patients with acute painful joint swelling and cardiovascular diseases.)

  • Warm-up and range of motion[9]
  • Strengthening (quad sets, supine straight leg raises, prone hip extensions, seated isometric knee extensions, single-leg leg presses, standing hamstring curls, and standing heel raises)
  • Aerobic program[9]
  • Cooling down with muscle stretching (quadriceps femoris, hamstring, and calf muscle stretching) 
  • Long-sitting knee flexion and extension range of motion, and treadmill walking
  • All lower-extremity exercises need to be performed bilaterally

Agility and perturbation training techniques[11]

Agility techniques:

  • Side stepping
  • Braiding (lateral stepping combined with forward and backward crossover steps)
  • Front crossover steps during forward ambulation
  • Back crossover steps during backward ambulation
  • Shuttle walking(forward and backward walking to and from designated markers)
  • A drill requiring multiple changes in direction

Perturbation techniques


NICE guidelines


  1. Altman R, Asch E, Bloch D, Bole G, Borenstein D, Brandt K, Christy W, Cooke TD, Greenwald R, Hochberg M, Howell D. Development of criteria for the classification and reporting of osteoarthritis: classification of osteoarthritis of the knee. Arthritis & Rheumatism: Official Journal of the American College of Rheumatology 1986 Aug;29(8):1039-49.
  2. Kuttner K, Goldberg VM. Osteoarthritis disorders Rosemout. InAmerican Academy of, Orthopedic Surgeons 1995 (pp. 21-25).
  3. Peyron JG. Epidemiologic and etiologic approach of osteoarthritis. WB Saunders. In: Seminars in Arthritis and Rheumatism 1979;8(4). pp. 288-306.
  4. 4.0 4.1 4.2 4.3 Crielaard JM, Dequeker J, Famaey JP. Osteoartrose. Brussels: Drukkerij Lichtert, 1985.
  5. Allander E, Behrend T, Henrard JC, Kelsey J, Leistner K, Masi A, Valkenberg H, Wysocki M. Rheumatology in perspective. The epidemiological view. Scandinavian journal of rheumatology. Supplement. 1982;46:1.
  6. Kelsey JL, Hochberg MC. Epidemiology of chronic musculoskeletal disorders. Annual review of public health 1988;9(1):379-401.
  7. Kellgren JH. Atlas of standard radiographs of arthritis. Volume II of The Epidemiologic of Chronic Rheumatism. Oxford: Blackwell, 1963.
  8. De Groot IB, Reijman M, Terwee CB, Bierma-Zeinstra SM, Favejee M, Roos EM, Verhaar JA. Validation of the Dutch version of the Hip disability and Osteoarthritis Outcome Score. Osteoarthritis and cartilage 2007;15(1):104-9.
  9. 9.0 9.1 9.2 McCarty DJ, Koopman WJ. Arthritis and allied conditions. Lea & Febiger: Philidelphia, London, 1993.
  10. Zhang W, Moskowitz RW, Nuki G, Abramson S, Altman RD, Arden N, Bierma-Zeinstra S, Brandt KD, Croft P, Doherty M, Dougados M. OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines. Osteoarthritis and cartilage 2008;16(2):137-62.
  11. Fitzgerald GK, Piva SR, Gil AB, Wisniewski SR, Oddis CV, Irrgang JJ. Agility and perturbation training techniques in exercise therapy for reducing pain and improving function in people with knee osteoarthritis: a randomized clinical trial. Physical therapy 2011;91(4):452-69.