Section 1: Epidemiology and aetiology
Osteoarthritis, the most common form of arthritis, is a clinical syndrome of synovial joints involving joint pain, functional limitation and impaired quality of life. It is associated with typical radiological joint changes.
Any synovial joint can be affected, but it most frequently occurs in the small joints of the hands, the knees, hips, spine and feet.
It is characterised by structural pathological changes to the joint, including loss of articular hyaline cartilage, synovial inflammation, repair of adjacent bone with new bone formation in the form of osteophytes, subchondral bone sclerosis, cyst formation, damage to menisci, muscle weakness, and ligamentous laxity and joint deformity.
It usually develops gradually and structural changes in the joint commonly occur without accompanying symptoms in the early stage.
Genetic factors Nodal osteoarthritis, a common form, runs in families. This particularly affects the small joints of the hands of middle-aged women. The overall familial estimates in nodal osteoarthritis for hand, knee and hip osteoarthritis are 40-60%.
Age Osteoarthritis mostly develops in people aged over 50. Although it is uncommon before then, it can develop in younger people.
Gender Osteoarthritis is more common and often more severe in postmenopausal women, especially in the knees and hands.
Obesity This is a well-documented risk factor. Increased weight causes high stresses at the joint surface.
Joint injury Major injuries, particularly intra-articular fracture, anterior cruciate ligament and meniscal injuries, are factors for developing osteoarthritis.
Joint laxity/instability due to deficient cruciate ligaments can lead to excessive uncontrolled gliding/sliding movements, which in turn lead to increased interfacial wear.
Infection Acute or tuberculous infection can lead to destruction of the joint and osteoarthritis.
Primary osteoarthritis is polyarticular arthritis of unknown aetiology that may involve several joints.
Secondary osteoarthritis is usually monoarticular and results from incongruity of a joint due to certain conditions, such as injury or infection.
Osteoarthritis of different joints, such as hips, knees and hands, does show a consistent age-related increase in prevalence.
The number of patients with symptomatic osteoarthritis in the UK is increasing due to the ageing population and risk factors such as obesity and lack of physical activity.
Section 2: Making the diagnosis
Osteoarthritis is diagnosed on the basis of history, clinical examination and special investigations.
Typical symptoms are activity-related pain, often at the end of the day, mostly relieved by rest, and associated with morning stiffness and impaired function.
Persistent rest and night pain are features of advanced osteoarthritis in some joints, including the knee and the hip.
The symptoms of osteoarthritis are variable and episodic in severity.
The European League Against Rheumatism (EULAR) suggests six criteria for certain diagnosis of osteoarthritis of the knee (see box).1
X-ray and physical examination give a sensitivity and specificity of 91% and 86%, respectively.2
Plain X-rays are the most useful test to confirm osteoarthritis and exclude other conditions. Radiographic features (loss of joint space, subchondral sclerosis, subchondral cysts, osteophytes and joint deformity) vary depending on the severity of the disease. However, radiological evidence does not correlate well with a patient's symptoms.
MRI is unmatched for non-invasive evaluation of articular cartilage.3 However, it should not be performed unless other diagnoses are suspected, including osteochondritis dissecans, meniscal injuries, pigmented villonodular synovitis, idiopathic bone oedema or avascular necrosis.4
Injudicious use of MRI can result in increased findings of asymptomatic meniscal tears (often present in older people) and lead to undesirable arthroscopic knee intervention.
A diagnosis of osteoarthritis of the knee may be made according to these three symptoms and signs, without imaging:
Section 3: Managing the condition
A holistic assessment of the patient's medical, social and psychological needs, function, quality of life, occupation, mood, relationships and leisure activities can help in tailoring treatment.5
Optimal management requires a combination of conservative non-pharmaceutical and pharmaceutical treatments, with surgical treatment reserved for severe cases.6
X-ray showing total knee replacement
Education about the disease, pain origin and treatment options should be provided. Studies have shown that regular telephone conversations with a healthcare professional can result in substantial improvement in pain and functional outcome in patients with osteoarthritis.7
Physical therapy is beneficial for all patients, regardless of disease and pain severity, disability, age or comorbidity. All patients with osteoarthritis of the hip, knee and spine should be encouraged to lose weight if needed. Walking aids, orthoses and splints may be beneficial.
Several pharmacological modalities are available to treat the symptoms of osteoarthritis. However, their use has to be justified in view of their side-effects.
Analgesics, anti-inflammatories Paracetamol is an effective first-choice drug. NSAIDs are indicated in patients who fail to respond to simple or topical analgesics.
Clinical studies provide some evidence for the use of glucosamine and chondroitin preparations, but mainly for their analgesic or antiinflammatory effects.8
NSAIDs or capsaicin are useful in patients who do not respond to oral analgesics, show a contraindication or cannot tolerate systemic drugs.9
Judicious use of intra-articular corticosteroids is appropriate in the management of osteoarthritis of the knee, most often in patients who have an effusion and local signs of inflammation.10
Intra-articular viscosupplements (hyaluronic acid) have shown superior pain relief to placebo and equivalent results to intra-articular corticosteroid injections, but with a considerable duration of action.11
Patients with mechanical symptoms of repeated locking, catching due to meniscal tear, or loose body with accompanying osteoarthritis of the knee can benefit from arthroscopic debridement.
Osteotomies around the knee joint are advocated for younger patients with unicompartmental osteoarthritis with associated varus or valgus deformity.12
Joint arthroplasty is a cost-effective method, but due to its irreversible nature, is reserved for cases of intractable pain, functional limitation and poor quality of life after conservative treatment has failed.
Unicompartmental knee arthroplasty is most commonly performed on the medial tibiofemoral compartment in relatively young patients with less severe osteoarthritis.
It has poorer long-term survival than total knee arthroplasty.13
Although isolated patellofemoral replacement is increasing, its failure rate is higher than that of total knee replacement.14
Section 4: Prognosis
Prognosis is determined by the joints involved, the severity of the condition, gender and obesity.
Old age, high BMI, varus deformity and involvement of multiple joints are associated with rapid progression of knee osteoarthritis.15
Patients with other comorbidities, specifically heart and lung disease, are also at higher risk of developing lower limb disability than those with knee osteoarthritis alone.16
Joint arthroplasty provides a good prognosis, with success rates generally exceeding 90% for hip and knee.
NICE guidelines recommend a tailored periodic review of patients with symptomatic osteoarthritis and information sharing should be a continuous, essential part of the management plan, rather than a single event at presentation.
Section 5: Case study
A 76-year-old man came to our specialist knee unit seeking advice for a four-year history of progressively worsening pain and stiffness in both knees, with prominent symptoms in his right knee.
He had difficulty walking for more than 20 minutes because of the pain and his symptoms were exaggerated by squatting and descending stairs.
Physical examination of the lower limbs revealed valgus deformity. His gait was antalgic and he had about 10 degrees of fixed flexion deformity. Range of motion was 10-100 degrees. Knee stability was examined in the coronal (varus/valgus) and sagittal (anteroposterior) planes.
Patients with lateral compartment involvement commonly have lateral pseudolaxity and vice versa. This is a feeling of varus laxity as the valgus deformity is manually corrected with the patient on the couch and the leg extended. This patient had lateral pseudolaxity. Mediolateral excursion of the patella was restricted.
Neurovascular examination showed normal distal pulses with normal neurological examination. A hip and back examination was performed to rule out any contribution to the knee symptoms.
X-ray revealed joint space narrowing, osteophytes and subchondral bone sclerosis in the right knee.
The patient had exhausted various pharmacological and non-pharmacological treatment options and had reached a stage where surgical intervention could be justified.
After considering his severe symptoms, lifestyle and comorbidities, he was offered total knee replacement. The patient was involved in the decision-making process and the procedure was explained in detail.
This operation has allowed the patient to return to his hobbies and activities of daily living, including golf, shopping and swimming.
This case illustrates how surgical management can help alleviate symptoms and maintain quality of life. However, a conservative management strategy combining pharmacological and non-pharmacological measures, such as strengthening exercises, weight reduction, orthotics and physiotherapy, can be successful in many patients and should be considered before making any decisions about surgical intervention.
Section 6: Evidence base
- NICE. The care and management of osteoarthritis in adults. CG59.
London, NICE, February 2008. www.nice.org.uk/CG59
- Brandt K, Doherty M, Lohmander LS. Osteoarthritis (second edition). Oxford, Oxford University Press, 2006.
- For more on rheumatology and musculoskeletal disorders, see statement 15.9 of the GP curriculum at gponline.com/curriculum
1. Zhang W, Doherty M, Peat G et al. Ann Rheum Dis 2010; 69: 483-9.
2. Altman R, Asch E, Bloch D et al. Arthritis Rheum 1986; 29(8): 1039-49.
3. Eckstein F, Cicuttni F, Raynauld JP et al. Osteoarthr Cartil 2006; 14: A46-75.
4. Hunter DJ, Felson DT. BMJ 2006; 332: 639-42.
5. Conaghan PG, Dickson J, Grant RL. BMJ 2008; 336: 502-3.
6. Zhang W, Moskowitz RW, Nuki G et al. Osteoarthr Cartil 2008; 16: 137-62.
7. Rene J, Weinberger M, Mazzuca SA et al. Arthritis Rheum 1992; 35: 511-15.
8. McAlindon TE, LaValley MP, Gulin JP et al. JAMA 2000; 283: 1469-75.
9. Altman RD, Aven A, Holmburg CE et al. Semin Arthritis Rheum 1994; 23 (suppl 3): 25-33.
10. Dieppe PA, Sathapatayavongs B, Jones HE et al. Rheum Rehabil 1980; 19: 212-17.
11. Patarnello F, Whitehead A. Rheumatol Europe 1997; 26(suppl 2): 73.
12. Fujisawa Y, Masuhara K, Shiomi S. Orthop Clin North Am 1979; 10(3): 585-608.
13. Koskinen E, Paavolainen P, Eskelinen A et al. Acta Orthopaedica 2007; 78(1): 128-35.
14. Ackroyd CE, Newman JH, Evans R et al. J Bone Joint Surg Br 2007; 89(3) 310-15.
15. Chapple CM, Nicholson H, Baxter GD et al. Arthritis Care Res (Hoboken) 2011; 63(8): 1115-25.
16. Ettinger WH, Davis MA, Neuhaus JM et al. J Clin Epidemiol 1994; 47: 809-15.
Contributed by Mr Abdul Waheed, senior knee fellow, and Mr George Dowd and Mr Howard Ware, consultant orthopaedic surgeons, The Royal Free and The Wellington Hospitals, north London.
|CPD IMPACT: EARN MORE CREDITS|
These further action points may allow you to earn more credits by increasing the time spent and the impact achieved.