ICD-11 Codes
for FA01.0 - Primary osteoarthritis of knee

Teodor Jurukovski January 1, 1970

Fact checked by: Teodor Jurukovski

Use Code

Understanding Primary Osteoarthritis of the Knee (ICD-11: FA01.0)

Primary osteoarthritis of the knee, identified by the ICD-11 code FA01.0, is a degenerative condition affecting the knee joint. It is characterised by the gradual breakdown of articular cartilage, often associated with age, genetic predisposition, or cumulative use. This process involves microscopic and macroscopic anatomical changes within the joint, including cartilage loss, the formation of bone spurs (osteophytes), sclerosis of the underlying bone, and the development of cysts. These changes can ultimately lead to limitations in joint motion. It is commonly referred to as knee OA or 'wear and tear' arthritis of the knee.

Common Symptoms and Presentation of Knee Osteoarthritis

The presentation of primary osteoarthritis of the knee can vary, but common symptoms include:

• Persistent knee pain, which typically worsens with activity and improves with rest.
• Stiffness in the knee, particularly noticeable in the morning or after periods of inactivity.
• Reduced range of motion in the knee joint.
• A grinding or clicking sensation (crepitus) during joint movement.
• Tenderness to touch around the affected joint.
• In some cases, joint swelling (effusion) or bony enlargement may occur.

It is important to note that some individuals with radiographic evidence of knee OA may be asymptomatic.

Key Risk Factors and Causes of Primary Knee Osteoarthritis

Primary osteoarthritis of the knee develops due to a complex interplay of factors. Key risk factors include:

• Age: The risk increases significantly with advancing age.
• Genetics: A predisposition can be inherited.
• Obesity: A higher body mass index (BMI) places increased stress on the knee joints.
• Previous Knee Trauma: Injuries to the knee joint can increase the likelihood of developing OA later in life.
• Repetitive Stress: Occupations or activities involving frequent kneeling, squatting, or repetitive knee movements are associated with increased risk.
• Sex: Females, particularly after menopause, tend to have a higher incidence and severity of knee OA.
• Mechanical Factors: Joint malalignment and biomechanical loading contribute to the condition.

The condition is considered a chronic disease affecting the entire joint structure, not just the cartilage.

Diagnosing Primary Osteoarthritis of the Knee

Diagnosis of primary osteoarthritis of the knee typically begins with a thorough clinical evaluation, including a review of the patient's medical history and a physical examination. Healthcare providers assess for characteristic symptoms such as pain, stiffness, and reduced mobility. Conventional radiography (X-rays) is a primary diagnostic tool used to visualise joint damage, including cartilage loss, osteophyte formation, and joint space narrowing. While X-rays are crucial, it is recognised that radiographic findings do not always correlate directly with the severity of pain experienced by the patient. In some instances, Magnetic Resonance Imaging (MRI) may be used to provide more detailed visualisation of soft tissues, cartilage, and bone marrow lesions, particularly when symptoms suggest meniscal or ligamentous damage not clearly seen on X-ray.

Management Strategies for Knee Osteoarthritis

Management of primary osteoarthritis of the knee focuses on alleviating symptoms, improving function, and slowing disease progression. Strategies often include:

• Pain Management: Over-the-counter or prescription pain relievers, and anti-inflammatory medications.
• Physical Therapy: Exercise programs designed to strengthen muscles around the knee, improve flexibility, and enhance joint stability.
• Lifestyle Modifications: Weight management is crucial for individuals who are overweight or obese, as reducing load on the knee can significantly alleviate symptoms.
• Assistive Devices: Canes or braces may help reduce stress on the joint.
• Injections: Corticosteroid or hyaluronic acid injections may provide temporary relief.
• Surgical Options: In severe cases, procedures such as arthroscopy, osteotomy, or knee replacement surgery may be considered.

Most patients can effectively manage their condition through conservative measures, often with support from primary care services.

Coding and Documentation for Primary Osteoarthritis of the Knee

The official ICD-11 code for Primary osteoarthritis of the knee is FA01.0. This code is used for accurate medical record documentation and billing purposes. ICD-11 allows for post-coordination to add further detail to the diagnosis. For instance, codes can be added to specify laterality (e.g., left, right, bilateral) or to indicate associated manifestations, such as chronic secondary musculoskeletal pain related to structural changes. When documenting this condition, using the exact ICD-11 code FA01.0 and the official term "Primary osteoarthritis of knee" ensures clarity and compliance with coding standards.