Osteoarthritis is the most prevalent form of arthritis, with an associated risk of mobility disability (defined as needing help with walking or climbing stairs)

Osteoarthritis of the knee causes pain, limits activity, and impairs quality of life. The societal burden (both in terms of personal suffering and use of health resources) is expected to increase with the increasing prevalence of obesity and the ageing of the community.

Osteoarthritis is a multifactorial process in which mechanical factors have a central role and is characterized by changes in structure and function of the whole joint.

There is no cure, and current therapeutic strategies are primarily aimed at reducing pain and improving joint function.

PATHOPHYSIOLOGY OF OSTEOARTHRITIS
Osteoarthritis is the clinical and pathological outcome of a range of disorders that results in structural and functional failure of synovial joints.

Traditionally, it has been considered a disease of articular cartilage.

The current concept holds that osteoarthritis involves the entire joint organ, including the subchondral bone, menisci, ligaments, periarticular muscle, capsule and synovium.

Systemic factors that increase the vulnerability of the joint to osteoarthritis include increasing age, female sex, and possibly nutritional deficiencies. genetic component to risk that is probably polygenic, the genes responsible have not yet been identified.

CLINICAL FEATURES OF KNEE OSTEOARTHRITIS
Typically osteoarthritis presents as joint pain

In contrast, the subchondral bone, periosteum, synovium and joint capsule are all richly innervated and could be the source of nociceptive stimuli in osteoarthritis.
DIAGNOSIS AND INVESTIGATIONS
The diagnosis of osteoarthritis is usually made clinically and then confirmed by radiography. The clinical features that suggest the diagnosis include pain, stiffness, reduced movement, swelling, crepitus, and increased age (unusual before age 40) in the absence of systemic features (such as fever).

Magnetic resonance imaging may be used to facilitate the diagnosis of other causes of knee pain that can be confused with knee osteoarthritis (such as osteochondritis dissecans and avascular necrosis).

Nearly all people with knee osteoarthritis have meniscal tears, and these are not necessarily a cause of increased symptoms. The menisci should not be removed unless there are symptoms of locking or extension blockade.
Because osteoarthritis is a non-inflammatory arthritis, laboratory findings are expected to be normal.

Aspirating a joint effusion should be considered if a diagnosis other than osteoarthritis (such as septic arthritis, gout, pseudogout) is suspected. Synovial fluid from affected joints is non-inflammatory (leucocyte count < 2000/mm3, clear, viscous).

MANAGEMENT OF KNEE OSTEOARTHRITIS
The aims of management are:

NON-PHARMACOLOGICAL TREATMENTS

Education: Encourage patients to participate in self managementprogrammes and provide resources for social support and instruction on coping skills.

Weight loss: Encourage overweight patients with osteoarthritis of the hip and knee to lose weight through a combination of diet and exercise.

Exercise: Exercise increases aerobic capacity, muscle strength and endurance and facilitates weight loss. Patients should be encouraged to take part in a low impact aerobic exercise programme (walking, cycling, or swimming or other aquatic exercises). Exercises to strengthen the quadriceps lead to reductions in pain and improvements in function.

Knee braces and orthotics: For those with instability of the knee and varus misalignment, valgus bracing and orthotics shift the load away from the medial compartment and, in doing so, may provide relief of pain and improvement in function.

PHARMACOLOGICAL TREATMENTS
These include oral analgesics like paracetamol, NSAIDs, Cox II inhibitors and topical agents like capsaicin.

Glucosamine and chondroitin seem to have the same benefit as placebo and there is controversy over whether they also have structure modifying benefits.

INTERVENTIONAL TREATMENTS IN PATIENTS WITH KNEE OSTEOARTHRITIS
Intra-articular steroids: When not otherwise contraindicated, intra-articular corticosteroids are of short term benefit for pain and function.

Intra-articular hyaluronic acid (viscosupplementation): Though the meta-analyses reviewing the efficacy of intra-articular hyaluronan are not in complete agreement, mainly because of variation in study methods, most suggest that the effect size is relatively small and the placebo response is significant

Coolief: Genicular Nerve Block & RF Neurotomy of Knee Joint
Chronic osteoarthritis pain of the knee is often not effectively managed with non-pharmacological or pharmacological treatments. Radiofrequency (RF) neurotomy (Coolief), when applied to articular nerve branches (genicular nerves), provides a therapeutic alternative for effective management of chronic pain associated with osteoarthritis of the knee.

INDICATIONS
Chronic knee pain secondary to osteoarthritis
Failed knee replacement
Unfit for knee replacement
Want to avoid surgery

Although surgery is generally effective for patients with advanced disease, some older individuals with comorbidities may not be appropriate surgical candidates. In addition some patients do not wish to consider surgery and prefer non- surgical options. In these patients, radiofrequency (RF) neurotomy of the genicular nerves might be a successful alternative to surgery. This procedure is based on the theory that cutting the nerve supply to a painful structure may alleviate pain and restore function.

PRP THERAPY
SURGERY
Surgery is indicated when conservative management has failed and there is a significant functional disability because of pain