Causes of knee Pain:
There are many causes of knee pain, common causes are:
Osteoarthritis of knee
Spondyloarthritis of Knee
Rheumatoid arthritis of Knee
Meniscus or cartilage injury
Osteo-Arthritis of knee is a very common problem of old age. It is one of the commonest cause of knee pain in India. It incapacitates many. Are you suffering from this? Apart from joint replacement there are few non-operative treatments for knee pain.
Cryoneurolysis was done for the 1st time in India by us with encouraging results.
Osteoarthritis is the commonest cause of knee pain and discussed here. Osteoarthritis is one of the commonest joint problems with 80% of the general population of radiologic evidence of osteoarthritis by 65 yrs of age. The disease process starts by age of around 20 yrs and manifests around 40 yrs. More than 40% of sufferers have no radiological evidence of osteoarthritis.
Pathogenesis of Osteo-Arthritis:
The exact etiology is not known. By chemical stress on articular cartilage and subchondral bone leads to wear and tear to these structures. Joint inflammation is very minimum compare to other arthritis and seen mostly in advanced disease. Pain of osteoarthritis may be due to the following reasons:
- Trabecular micro-fracture
- Intraosseous hypertension
- Periosteal irritation
- Stretching of join capsule and ligaments
- Muscle spasm
- Low-grade inflammation of the knee joint
Central sensitization contributes considerably to producing pain.
Pain around the joint that increases with weight-bearing and movement and improves with rest is the commonest presenting symptom. It may be associated with morning stiffness and swelling of the joints. Clinical signs are tenderness, crepitus, joint effusion, decreased range of movement, valgus/varus deformity etc. X-ray shows decreased joint space, osteophytes formation, and osteoporosis of subchondral bone.
I. Non-pharmacological therapy
- Reduction of obesity- loss of weight decreases load on the weight-bearing joints and thereby retards the disease process.
- Quadriceps strengthening exercises- It is very useful for patients with osteoarthritis of knee. Strengthening of quadriceps muscle improves knee pain and function.
- A walking stick to be held in the opposite hand of the affected joint, reduces the load on the joint and is associated with decreased pain and improved function.
- Deformity stabilization- use of proper shoes for varus or valgus deformity transfers the load to the other compartment and retards the disease process.
II. Pharmacological therapy
- Paracetamol /acetaminophen should be used as the first line of therapy. The dosage recommended is from 1500 mg/day to a maximum of 4000 mg/day. Though paracetamol does not have anti-inflammatory properties, still it provides good pain relief and osteoarthritis also does not show a major inflammatory component.
- Those who do not get adequate relief with oral paracetamol should be given weak opioids like tramadol, codeine, or dextropropoxyphene along with Paracetamol. There are several combinations of Paracetamol with opioids that should be tried and may be used for a prolonged period without significant side effects.
- As the next line of therapy NSAIDs can be tried. Ibuprofen 1200 mg to 2400 mg/day is the first line NSAID. If the relief is not adequate, paracetamol can be added up to 4 g along with ibuprofen. These medicines should not be used for a prolonged period.
- Co-analgesics like Duloxetine is the most commonly used co-analgesics. This approved by US FDA for OA knee.
- There are some so-called diseases modifying agents that had generated a lot of interest, claiming that some of them may help in the regeneration of cartilage and others inhibit degeneration. Others are diacerein, doxycycline, etc. Recent Studies do not recommend these group of medicines and they do not help in regeneration.
- Intraarticular injections-patients with severe pain of the knee, joint effusions, and local signs of inflammation benefit from intraarticular injections of corticosteroids (triamcinolone 40 mg). This will be effective for a short term period in reducing pain and increasing quadriceps strength. Some patients will require about 2 to 3 injections in a year, to using aseptic precautions, the infection rate is negligible. Sometimes mild flare-ups might be seen in joint inflammation following intraarticular injections. Repeated steroid injections are not recommended for the fear of damaging the cartilage of weight-bearing joints.
- Tidal irrigation- The principle is washing off the inflammatory mediators, debris, and breaking adhesions. Closed tidal knee irrigation with normal saline is done under local anesthesia; this is as good as arthroscopic lavage. Saline is infused into the knee to distend the capsule and then is withdrawn. A total of 1 ½ to 2 liters is used for this kind of irrigation. Patients feel improvement in their joint mobility along with a reduction of stiffness. This procedure has to be done under aseptic precautions.
- Arthroscopy- This will be useful in meniscal tear and other internal derangements.
- Prolotherapy and Prolozone Therapy. Injection of tissue proliferates (like ozone, dextrose, etc.) inside the joint and around the joint reduces pain, inflammation and it strengthens ligaments. It is also claimed that they promote cartilage growth.
- Visco-supplementation- High molecular weight hyaluronic acid resembling synovial fluid is very helpful particularly in early osteoarthritis with knee pain.
- Platelet Rich Plasma Injection– Like its usefulness in other degenerative diseases, it is useful in osteoarthritis of the knee also. It is becoming popular throughout the world.
- Radio-Frequency Procedure – This procedure is a very effective procedure in knee pain and is approved by the US FDA. Genicular nerves carrying knee pain are blocked with this procedure.
- Patients having very severe symptoms should be considered for surgical options like tibial osteotomy, arthroplasty, and joint replacement. Surgical options should be considered, once the medical line of treatment and interventions are failed. Surgical options should be delayed as much because the total joint arthroplasty might last between 10-20 years. Patients will have to modify his/her lifestyle to a certain extent because of the ergonomics of the replaced joint.