Osteoarthritis of the Knee: Causes, Symptoms, and Treatment

What Is Osteoarthritis of the Knee?

Osteoarthritis of the knee occurs when the cartilage that cushions the bones of the knee joint begins to break down. This leads to the bones rubbing against each other, causing pain, swelling, and loss of movement. OA is a progressive condition, meaning that it can worsen over time. It is most common in older adults, but can also develop in younger individuals as a result of injury or repetitive stress.

Causes of Osteoarthritis in the Knee

Age

As we age, the cartilage in our joints naturally wears down. The risk of developing knee OA increases as people get older, especially after the age of 50.

Previous Knee Injuries

Injuries such as fractures, ligament tears, or meniscus tears can increase the risk of developing OA later in life. Even old injuries can contribute to abnormal joint movement, leading to premature cartilage breakdown.

Overuse

Repetitive movements and overuse of the knee joint in activities such as running, jumping, or heavy lifting can accelerate cartilage wear. People in physically demanding jobs or athletes involved in high-impact sports are particularly at risk.

Genetics

Genetic factors can play a role in the development of knee OA. Family history can increase the likelihood of developing this condition.

Obesity

Carrying excess weight puts additional strain on the knee joints, leading to increased wear and tear on the cartilage, which can contribute to the development of osteoarthritis.

Abnormal Joint Alignment

Conditions such as flat feet, bowed legs (varus deformity), or knock-knees (valgus deformity) can cause the knee joint to misalign, leading to uneven stress on the cartilage and contributing to OA.

Gender

Women are more likely to develop knee OA than men, particularly after the age of 50. Hormonal changes after menopause may contribute to this increased risk.

Symptoms of Osteoarthritis of the Knee

Symptoms of knee osteoarthritis may vary in severity, but they commonly include:

• Knee Pain: Pain that worsens with activity, particularly weight-bearing activities such as walking, climbing stairs, or standing for prolonged periods.

• Stiffness: Difficulty bending or straightening the knee, especially after long periods of inactivity or first thing in the morning.

• Swelling: The knee may become swollen, especially after activity or prolonged use.

• Reduced Range of Motion: Limited ability to move the knee joint fully due to pain, swelling, or mechanical blockages from damaged cartilage.

• Grinding Sensation (Crepitus): A feeling of grinding or popping when moving the knee, due to the rough surfaces of the bones rubbing together.

• Weakness: The muscles around the knee may weaken due to disuse, which can further exacerbate pain and instability.

Diagnosing Osteoarthritis of the Knee

A thorough assessment is necessary to diagnose knee osteoarthritis. Your healthcare provider may perform the following steps:

Clinical Examination

A physical examination will assess the range of motion, stability, and alignment of the knee joint. Tenderness around the knee, signs of swelling, and the presence of crepitus may indicate OA.

Imaging Studies

• X-rays: X-rays are the most common method used to diagnose knee osteoarthritis. They can reveal joint space narrowing, bone spurs (osteophytes), and other changes indicative of OA.

• MRI: An MRI may be used if your healthcare provider suspects damage to soft tissues such as the cartilage or ligaments.

Treatment for Osteoarthritis of the Knee

Non-Surgical Treatment

1. Physical Therapy

   • Strengthening Exercises: Focus on strengthening the muscles around the knee, particularly the quadriceps, hamstrings, and calf muscles. Strong muscles help to support the knee joint and reduce pain.

   • Stretching: Stretching the muscles around the knee and the hip can help improve flexibility and reduce stiffness.

   • Manual Therapy: Hands-on techniques used by physiotherapists can help to improve joint mobility and reduce pain.

   • Aquatic Therapy: Exercising in water can reduce stress on the knee joint while improving strength and flexibility.

2. Pain Relief

   • NSAIDs: Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can help reduce pain and inflammation in the knee joint.

   • Acetaminophen: Acetaminophen (paracetamol) is another option for managing pain, especially for individuals who cannot take NSAIDs.

   • Ice Therapy: Applying ice to the knee for 15-20 minutes at a time can help reduce inflammation and alleviate pain.

3. Weight Management

   • Losing Weight: Reducing excess weight can help decrease the stress placed on the knee joint, which can alleviate symptoms of osteoarthritis and prevent further cartilage damage.

4. Assistive Devices

   • Knee Braces: A knee brace can provide stability and support to the knee joint, particularly during physical activities.

   • Orthotic Inserts: Custom orthotics may help to improve alignment and reduce stress on the knee joint.

5. Corticosteroid Injections

   • Injections of corticosteroids can be used to reduce inflammation and relieve pain, providing short-term relief.

6. Viscosupplementation

   • Hyaluronic acid injections can help lubricate the knee joint, reduce pain, and improve mobility, especially in patients with moderate to severe OA.

Surgical Treatment

If non-surgical treatments do not provide sufficient relief, surgical options may be considered, particularly in advanced stages of OA.

1. Arthroscopy

   • In some cases, knee arthroscopy (a minimally invasive procedure) can be used to remove damaged cartilage or smooth rough surfaces of the joint.

2. Osteotomy

   • Osteotomy involves reshaping the bones around the knee to correct alignment and relieve pressure on the joint. This procedure is most often recommended for younger patients with localized knee OA.

3. Partial Knee Replacement

   • In cases where OA has only affected one part of the knee, a partial knee replacement (also called unicompartmental knee replacement) may be performed. This procedure replaces only the damaged portion of the knee.

4. Total Knee Replacement

   • For severe cases of OA where the entire knee joint is affected, a total knee replacement may be necessary. In this procedure, the damaged knee joint is replaced with a prosthetic.

Recovery and Prognosis

• Non-Surgical Recovery: For individuals who follow a comprehensive rehabilitation program, the prognosis for knee OA is often good. Physical therapy, weight management, and pain management can help control symptoms and improve function.

• Surgical Recovery: After surgery, recovery time varies depending on the procedure. Most patients can resume daily activities within a few months, but a full recovery may take up to 6 months or longer, especially after a total knee replacement.

Preventing Osteoarthritis of the Knee

While it may not be possible to completely prevent knee OA, several strategies can help reduce the risk and manage symptoms:

• Maintain a Healthy Weight: Reducing excess body weight will reduce the load on the knee joint and decrease the risk of developing OA.

• Exercise Regularly: Low-impact activities such as swimming, cycling, and walking can help maintain joint flexibility and strength without overloading the knee.

• Strengthen Muscles Around the Knee: A strong quadriceps and hamstrings can protect the knee from injury and help reduce the wear on cartilage.

• Avoid Repetitive High-Impact Activities: Reducing activities that place repetitive stress on the knee joint can help slow the progression of OA.

Osteoarthritis of the knee is a common condition that can cause significant discomfort and limit your ability to move freely. However, with the right management strategies, including physical therapy, weight management, and possibly surgery, many people can manage symptoms and continue to live active, fulfilling lives. If you're experiencing knee pain or suspect you have knee osteoarthritis, contact Palms Physiotherapy & Allied Health to schedule an appointment and discuss your treatment options.