Knee Osteoarthritis Treatment London | Private Ultrasound Diagnosis & Injections

Knee Arthritis Explained

Basic Knee Joint Anatomy

Knee osteoarthritis is the term used for age-related degenerative changes in the knee joint.

The anatomy of the knee comprises three compartments:

1️⃣ The medial (inner) compartment — the weight-bearing joint formed by the femur and tibia

2️⃣ The lateral (outer) compartment — also a weight-bearing joint between the femur and tibia

3️⃣ The patellofemoral compartment — formed by the patella (kneecap) sliding up and down within a specialised groove on the femur, known as the trochlea

Causes of Knee Osteoarthritis

Knee osteoarthritis can affect all three compartments (tri-compartmental osteoarthritis) or may affect just one or two compartments.

Risk factors for developing knee osteoarthritis include:

• The shape of the knee anatomy, which is formed during development

• Certain types of trauma to the knee

The specifics of these risk factors often influence which compartments of the knee are most affected by osteoarthritis.

Diagnosing Knee Osteoarthritis

The formal diagnosis of knee osteoarthritis is based on a comprehensive physical examination and may be verified by X-ray. However, ultrasound imaging can also provide valuable diagnostic information, particularly in suspected early cases of knee osteoarthritis.

Typical features seen on ultrasound include:

• Bony irregularity of the joint margins

• Osteophytes (bony spurs) — particularly in more advanced cases

• Joint effusion or capsular swelling

Additionally, ultrasound is extremely useful in determining whether any swelling is due to inflammation of the joint capsule and synovium, or fluid emanating from the joint itself.

Ultrasound Guided Injections for Knee Osteoarthritis

How is an Injection Administered for Knee Osteoarthritis?

Once a diagnosis is established, ultrasound can be used to aspirate excess joint fluid if present, prior to administering an ultrasound-guided injection.

There are two typical ultrasound-guided injection approaches for the knee:

1️⃣ Medial approach:

• The ultrasound probe is placed with the far end on the inner side of the patella, and the near end on the inner side of the femoral condyle.

• This view allows the clinician to visualise the patellofemoral ligament and the joint recess.

• The needle is then clearly visualised passing into the medial knee joint.

2️⃣ Supralateral recess approach:

• The ultrasound probe is placed at an oblique angle, with the far side over the lateral aspect of the patella, and the near side angled to visualise the supralateral recess of the knee.

• In this view, any joint effusion can be seen clearly.

• The needle is visualised entering this recess, following the path beneath the ultrasound probe.

• This approach is generally favoured when aspiration of joint fluid is planned prior to the injection.

What to Do After Your Knee Ultrasound Guided Injection

Needle Path & Post-Injection Pain
Knee joint injections can be performed using either a medial approach or a superolateral recess approach. In some cases, particularly with osteoarthritic joints that have large osteophytes, a medial approach may cause minor needle trauma to access the joint. This can result in soreness for 2–3 days after the local anaesthetic has worn off.

If fluid aspiration is performed during the procedure, many patients notice an immediate improvement in comfort and mobility. A post-injection flare can rarely occur, typically lasting 2–3 days, and is thought to be related to the medication interacting with the synovial fluid.

Wound Care & Infection Risk
Avoid exposing the injection site to dirty or public water (e.g., swimming pools, hot tubs) for 2–3 days to reduce infection risk. Monitor for redness, swelling, or discharge at the injection site and contact me immediately if these occur.

Activity Guidance
If the injection was performed for osteoarthritis, sensible graded activity can usually resume after 2–3 days, provided symptoms allow.

If the injection was for a meniscal issue or similar problem in a younger joint, it is best to offload the knee for 10 days before returning to a graded physical therapy and gym routine.

Follow-Up
If you experience unusual pain, swelling, redness, or any other concerns following your injection, please contact me immediately.

Other Treatments for Knee Osteoarthritis

Mobility Exercises for Knee Arthritis

Strengthening Exercises for Knee Arthritis

Advanced Strengthening Exercises for Knee Arthritis

Knee Osteoarthritis | Evidence base

Exercise therapy and lifestyle modification are strongly supported by international guidelines (e.g. NICE, ACR, OARSI) as foundational in managing knee OA. Quadriceps strengthening, aerobic conditioning, and joint mobility work improve pain, function, and delay disease progression. Corticosteroid injections may offer short-term relief, particularly in inflammatory flares, but repeated use is discouraged due to possible cartilage degradation. Hyaluronic acid injections provide a safer alternative with modest but clinically relevant symptom improvement, particularly in early to moderate OA. Total knee replacement offers excellent long-term outcomes for patients with advanced disease and substantial impairment, and should be considered when conservative measures fail.

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