Osteoarthritis

Risk Factors

Osteoarthritis has a multifactorial aetiology and can be primary (with no obvious cause) or secondary (due to trauma, infiltrative disease or connective tissue diseases).

Risk factors for primary OA include obesity, advancing age, female gender, and manual labour occupations.

Clinical Features

The most common joints affected by osteoarthritis are the small joints of the hands and feet, the hip joint, and the knee joint.

Patients typically present with symptoms that are insidious, chronic, and gradually worsening. Clinical features include pain and stiffness in joints, worsened with activity* and relieved by rest. Pain tends to worsen throughout the day, whereas stiffness tends to improve. Prolonged OA results in deformity and a reduced range of movement.

On examination, inspect for deformity; there are some common characteristic findings depending on the joint affected, such as Bouchard nodes (swelling of PIPJs) or Heberden nodes (swelling of DIPJs) in the hands, and fixed flexion deformity or varus malalignment in the knees.

Feel for crepitus throughout the range of movement. Movement of the joint is generally reduced and painful.

*Joint stiffness and pain that improves with activity is characteristically seen in inflammatory arthropathies (e.g. rheumatoid arthritis).

By Drahreg01 (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

Figure 2
Heberden’s nodes (DIPJs) and Bouchard’s nodes (PIPJs) are both features of osteoarthritis

Differential Diagnosis

The differential diagnoses for osteoarthritis will depend on which area of the body is affected. However, some universal conditions include inflammatory arthropathies (e.g. rheumatoid arthritis), crystal arthropathies (e.g. gout or CPPD), septic arthritis, fractures, bursitis, or malignancy (primary or metastatic).

Joint specific differential diagnoses for osteoarthritis:

• Hand – De Quervain’s tenosynovitis, rheumatoid arthritis, and gout
• Hip – trochanteric bursitis, radiculopathy, spinal stenosis, or iliotibial band syndrome
• Knee – meniscal or ligament tears, or chondromalacia patellae

Investigations

Osteoarthritis is primarily a clinical diagnosis. Investigations can be used to exclude differential diagnosis; routine blood tests can be useful to exclude inflammatory or infective causes and radiographs are useful for confirming the diagnosis (Fig. 3) and excluding fractures.

Radiological Appearances

The classical radiological features of osteoarthritis are:

• Loss of joint space
• Osteophytes
• Subchondral cysts
• Subchondral sclerosis

Adapted from Mikael Häggström (Own work) [CC0], via Wikimedia Commons, from Jmarchn (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons, and from Jmarchn (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Figure 3
Radiographic evidence of osteoarthritis affecting (A) hip (B) elbow (C) ankle

Management

The management of osteoarthritis involves options ranging from conservative to medical to surgical.

Conservative

Patients should be educated about their condition and its progression, including advise on joint protection and emphasising the importance of strengthening and exercise. Patients who are overweight should also be advised on weight loss.

Some non-pharmacological interventions that can be offered include local heat or ice packs, joint supports, and physiotherapy (most effective option for longer-term outcomes).

Medical

Simple analgesics and topical NSAIDs are the mainstay of most medical management for OA, alongside the conservative measures.

There is varying success with the use of intra-articular steroid injections*. These are commonly administered in the outpatient clinic in cases where the presence of pain remains despite oral analgesics.

*Steroid injections are typically mixed with local anaesthetic; whilst this improves the patients symptoms for a few hours, there is often a subsequent ‘steroid flare’, during which the patient’s symptoms worsen for a few days.

Surgical

If conservative and medical interventions fail, then surgical intervention may be considered, especially if their joint symptoms have a substantial impact on their quality of life.

The mainstay of management is with arthroplasty, however other options include osteotomy and arthrodesis (joint fusion)