Osteoarthritis of the Knee.
What is knee osteoarthritis?
Osteoarthritis (OA) of the knee is a degenerative joint condition in which the articular cartilage covering the ends of the femur, tibia and patella gradually breaks down, reducing the joint's ability to absorb load and move smoothly. As the cartilage thins and deteriorates, the underlying bone is exposed, osteophytes (bone spurs) form around the joint margins, and the surrounding soft tissues become inflamed and thickened. The result is pain, stiffness, swelling and progressive difficulty with walking, stairs and daily activities.
Knee OA is the most common form of arthritis and one of the most prevalent musculoskeletal conditions in Australia, affecting approximately one in five adults over 45 and becoming increasingly prevalent with age. It is the leading indication for total knee replacement surgery in Australia, with over 60,000 procedures performed annually.
What causes knee osteoarthritis?
Knee OA develops from a combination of factors rather than a single cause. Age is the most significant risk factor — cartilage naturally loses its repair capacity over time. Being overweight significantly increases the compressive load on knee cartilage and accelerates breakdown — every kilogram of body weight applies approximately three to five kilograms of force to the knee during walking. Previous knee injuries — particularly meniscal tears, ACL injuries and patellofemoral pain — substantially increase OA risk in the affected compartment. Genetics, female sex and occupational loading are also recognised contributors.
The persistent misconception that OA is simply caused by "too much exercise" is not supported by evidence. Regular, appropriate exercise is actually protective of joint cartilage — it is the combination of abnormal joint mechanics, loading asymmetries and metabolic factors that drives pathological cartilage breakdown, not activity itself.
What are the symptoms?
Physiotherapists use various techniques to alleviate pain, including manual therapy such as joint mobilisation and soft tissue massage. Symptoms include pain in and around the knee joint that is typically worse with activity and improves with rest in earlier stages, though rest pain and night pain develop as the condition progresses. Stiffness — particularly in the morning or after sitting for a prolonged period — is characteristic. Swelling, joint line tenderness and crepitus (clicking or grinding with movement) are common. Range of motion progressively reduces — full extension and deep flexion are typically the first movements affected.
How is it diagnosed?
Knee OA is typically diagnosed on clinical examination combined with plain X-ray showing joint space narrowing, osteophyte formation, subchondral sclerosis and subchondral cysts. As with other degenerative conditions, imaging findings must be interpreted in clinical context — X-ray changes are common in asymptomatic adults and the severity of radiographic OA does not reliably predict symptom severity.
The evidence against arthroscopy
An important and often underappreciated clinical fact: knee arthroscopy — including arthroscopic washout and debridement — has been shown in multiple large randomised controlled trials to produce no greater benefit than sham surgery for knee osteoarthritis pain. Major clinical guidelines including those of the Australian Physiotherapy Association and Arthritis Australia now recommend against knee arthroscopy for OA in the absence of specific mechanical symptoms, in favour of non-surgical management. This is a significant shift and one that positions physiotherapy and exercise as the primary and most effective interventions.
How can physiotherapy and exercise physiology help?
Exercise is the single most evidence-based non-pharmacological treatment for knee OA and is recommended as first-line management by Arthritis Australia and international clinical guidelines. Exercise does not damage an arthritic knee — it helps maintain cartilage nutrition, builds the muscular support that reduces joint loading, reduces pain through neurological mechanisms, and maintains the functional capacity that determines quality of life.
A tailored exercise program is a fundamental component of physiotherapy for knee osteoarthritis. Exercises focus on strengthening the muscles around the knee, especially the quadriceps, hamstrings, and calf muscles. Stronger muscles provide better support to the joint, reducing pain and improving stability. Range of motion and flexibility exercises maintain joint mobility and reduce stiffness. Balance and proprioception exercises reduce fall risk.
Quadriceps strengthening is the most critical exercise target — quadriceps weakness is one of the most consistent findings in knee OA and correlates directly with pain severity and functional limitation. VMO retraining using real time ultrasound ensures the correct muscle is activating rather than superficial compensators. Hip abductor and gluteal strengthening reduces the dynamic valgus loading that worsens medial compartment OA — one of the most important and most commonly overlooked components of knee OA management.
Manual therapy — joint mobilisation — reduces pain and improves mobility through neurophysiological mechanisms, providing short-term symptom relief that facilitates participation in the exercise program. Clinical Pilates provides an excellent low-impact environment for knee and hip strengthening with precise load control — the reformer allows meaningful strengthening without the high joint loads of conventional gym training.
Exercise physiology contributes to the cardiovascular fitness and overall functional capacity component of knee OA management, which is significantly impaired in many patients. For patients with co-occurring conditions including obesity, diabetes or cardiovascular disease, exercise physiology addresses these simultaneously. Eligible patients may access exercise physiology through a Chronic Disease Management Plan with a GP referral.
Prehabilitation before total knee replacement
For patients whose knee OA has progressed to the point where total knee replacement is being considered, physiotherapy and exercise physiology before surgery — prehabilitation — improves post-operative outcomes significantly. Patients who arrive for surgery with stronger quadriceps and better overall function recover faster, achieve better functional outcomes and have shorter hospital stays. If you are on a waiting list for TKR, starting prehabilitation now is one of the most valuable things you can do.
Our physiotherapists Eliane Machado, Bethany Kippen and Exercise Physiologist Ash O'Regan all have experience in knee OA management and are members of the Australian Physiotherapy Association. Eliane's doctoral research in knee biomechanics is directly relevant to the movement analysis and rehabilitation planning that produces the best outcomes for knee OA patients.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
Osteoarthritis (OA) of the knee is a degenerative joint condition in which the articular cartilage covering the ends of the femur, tibia and patella gradually breaks down, reducing the joint's ability to absorb load and move smoothly. As the cartilage thins and deteriorates, the underlying bone is exposed, osteophytes (bone spurs) form around the joint margins, and the surrounding soft tissues become inflamed and thickened. The result is pain, stiffness, swelling and progressive difficulty with walking, stairs and daily activities.
Knee OA is the most common form of arthritis and one of the most prevalent musculoskeletal conditions in Australia, affecting approximately one in five adults over 45 and becoming increasingly prevalent with age. It is the leading indication for total knee replacement surgery in Australia, with over 60,000 procedures performed annually.
What causes knee osteoarthritis?
Knee OA develops from a combination of factors rather than a single cause. Age is the most significant risk factor — cartilage naturally loses its repair capacity over time. Being overweight significantly increases the compressive load on knee cartilage and accelerates breakdown — every kilogram of body weight applies approximately three to five kilograms of force to the knee during walking. Previous knee injuries — particularly meniscal tears, ACL injuries and patellofemoral pain — substantially increase OA risk in the affected compartment. Genetics, female sex and occupational loading are also recognised contributors.
The persistent misconception that OA is simply caused by "too much exercise" is not supported by evidence. Regular, appropriate exercise is actually protective of joint cartilage — it is the combination of abnormal joint mechanics, loading asymmetries and metabolic factors that drives pathological cartilage breakdown, not activity itself.
What are the symptoms?
Physiotherapists use various techniques to alleviate pain, including manual therapy such as joint mobilisation and soft tissue massage. Symptoms include pain in and around the knee joint that is typically worse with activity and improves with rest in earlier stages, though rest pain and night pain develop as the condition progresses. Stiffness — particularly in the morning or after sitting for a prolonged period — is characteristic. Swelling, joint line tenderness and crepitus (clicking or grinding with movement) are common. Range of motion progressively reduces — full extension and deep flexion are typically the first movements affected.
How is it diagnosed?
Knee OA is typically diagnosed on clinical examination combined with plain X-ray showing joint space narrowing, osteophyte formation, subchondral sclerosis and subchondral cysts. As with other degenerative conditions, imaging findings must be interpreted in clinical context — X-ray changes are common in asymptomatic adults and the severity of radiographic OA does not reliably predict symptom severity.
The evidence against arthroscopy
An important and often underappreciated clinical fact: knee arthroscopy — including arthroscopic washout and debridement — has been shown in multiple large randomised controlled trials to produce no greater benefit than sham surgery for knee osteoarthritis pain. Major clinical guidelines including those of the Australian Physiotherapy Association and Arthritis Australia now recommend against knee arthroscopy for OA in the absence of specific mechanical symptoms, in favour of non-surgical management. This is a significant shift and one that positions physiotherapy and exercise as the primary and most effective interventions.
How can physiotherapy and exercise physiology help?
Exercise is the single most evidence-based non-pharmacological treatment for knee OA and is recommended as first-line management by Arthritis Australia and international clinical guidelines. Exercise does not damage an arthritic knee — it helps maintain cartilage nutrition, builds the muscular support that reduces joint loading, reduces pain through neurological mechanisms, and maintains the functional capacity that determines quality of life.
A tailored exercise program is a fundamental component of physiotherapy for knee osteoarthritis. Exercises focus on strengthening the muscles around the knee, especially the quadriceps, hamstrings, and calf muscles. Stronger muscles provide better support to the joint, reducing pain and improving stability. Range of motion and flexibility exercises maintain joint mobility and reduce stiffness. Balance and proprioception exercises reduce fall risk.
Quadriceps strengthening is the most critical exercise target — quadriceps weakness is one of the most consistent findings in knee OA and correlates directly with pain severity and functional limitation. VMO retraining using real time ultrasound ensures the correct muscle is activating rather than superficial compensators. Hip abductor and gluteal strengthening reduces the dynamic valgus loading that worsens medial compartment OA — one of the most important and most commonly overlooked components of knee OA management.
Manual therapy — joint mobilisation — reduces pain and improves mobility through neurophysiological mechanisms, providing short-term symptom relief that facilitates participation in the exercise program. Clinical Pilates provides an excellent low-impact environment for knee and hip strengthening with precise load control — the reformer allows meaningful strengthening without the high joint loads of conventional gym training.
Exercise physiology contributes to the cardiovascular fitness and overall functional capacity component of knee OA management, which is significantly impaired in many patients. For patients with co-occurring conditions including obesity, diabetes or cardiovascular disease, exercise physiology addresses these simultaneously. Eligible patients may access exercise physiology through a Chronic Disease Management Plan with a GP referral.
Prehabilitation before total knee replacement
For patients whose knee OA has progressed to the point where total knee replacement is being considered, physiotherapy and exercise physiology before surgery — prehabilitation — improves post-operative outcomes significantly. Patients who arrive for surgery with stronger quadriceps and better overall function recover faster, achieve better functional outcomes and have shorter hospital stays. If you are on a waiting list for TKR, starting prehabilitation now is one of the most valuable things you can do.
Our physiotherapists Eliane Machado, Bethany Kippen and Exercise Physiologist Ash O'Regan all have experience in knee OA management and are members of the Australian Physiotherapy Association. Eliane's doctoral research in knee biomechanics is directly relevant to the movement analysis and rehabilitation planning that produces the best outcomes for knee OA patients.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
