Beyond Rehab Physiotherapy

What is Knee and Hip Osteoarthritis?

Knee and hip osteoarthritis (OA) is a common joint condition that affects how smoothly the joint moves and how comfortable it feels during daily activities. The knee and hip are designed to handle large loads with every step, squat, and turn. Over time, or after injury, the joint tissues can become less well-coordinated and more sensitive, which can lead to pain, stiffness, or reduced confidence in movement.

In osteoarthritis, changes can occur in several parts of the joint — including the cartilage, bone, ligaments, and muscles. Importantly, OA is not simply “wear and tear.” Modern research shows that pain and function are influenced by how the whole joint system works, how strong and coordinated the muscles are, and how the nervous system processes signals from the joint.

Many people with OA have periods where symptoms flare and settle again. Others improve significantly with the right type of movement and strengthening. Imaging findings (like X-rays or MRIs) do not reliably predict how much pain or disability someone will have, and people with similar scans can feel very different.

The encouraging part is that the joint remains adaptable. With the right loading, education, and support, people with knee and hip OA can build strength, improve confidence in movement, and stay active in the things that matter to them.

Impact of Osteoarthritis

Knee and hip osteoarthritis (OA) in Australia imposes a substantial individual, social, and healthcare cost burden. Over 3 million Australians are affected, with prevalence and disability rates rising sharply due to population ageing and obesity. OA is now a leading cause of years lived with disability, surpassing many other chronic diseases. The annual direct health system expenditure for OA is projected to exceed AU$11.9 billion by 2040, driven by hospitalisations, joint replacements, and ongoing care. Indirect costs include lost productivity, work disability, and reduced participation in social and community life, with significant impacts on quality of life and mental health for individuals and their families.[1-2]

Overview of Treatment

First-line management, as recommended by all major international societies, is non-pharmacological: structured education and exercise therapy, weight management, and self-management support. Exercise and physiotherapy-led interventions consistently demonstrate moderate improvements in pain, function, and quality of life for both knee and hip OA, with benefits sustained for at least 2–6 months post-intervention and no evidence of harm or disease progression.[3-4] Mechanisms include improved muscle strength, joint stability, neuromuscular control, and reduced systemic inflammation. Adjunctive therapies (e.g., electrophysical agents, manual therapy) provide only small, non-clinically meaningful additional benefits over exercise alone.[5]

Randomized Controlled Trials: Key Results and Takeaways

Major RCTs (KANON, COMPARE, ACL SNNAP) confirm that structured rehabilitation is a reasonable first-line approach for many patients, with up to 40–50% of those initially managed nonoperatively eventually opting for delayed reconstruction due to instability or functional limitations. ^[1][7]

• The COMPARE trial found that younger, more active patients were more likely to fail nonoperative management and require delayed surgery, typically within 3–6 months. ^[7]
• The ACL SNNAP trial showed no significant difference in quality-of-life or functional outcomes between rehabilitation and reconstruction at 1 year, but a substantial proportion of conservatively managed patients ultimately required surgery. ^[1]
• The cross-bracing protocol demonstrated MRI evidence of ACL healing in 90% of patients at 3 months, with better functional outcomes and return-to-sport rates in those with more complete healing. ^[3]

Guideline Recommendations and Decision-Making

The American Academy of Orthopaedic Surgeons (AAOS) recommends a patient-centered, risk-stratified approach, emphasizing shared decision-making. ^[2]

• Initial management should be individualized based on instability, age, and patient preferences. ^[2][7]
• Criteria for surgery include persistent instability, and failure of rehabilitation. ^[2]
• Rehabilitation protocols are be criterion-based, with return-to-sport only after achieving ≥90% limb symmetry in strength and hop tests, and psychological readiness.^[2]

Special Scenarios: First-Time Ruptures, Graft Failures, and High-Risk Groups

For first-time ACL ruptures, initial rehabilitation is appropriate for most, with better outcomes for surgery for those with high recurrent instability.

• Graft failures are typically managed with revision reconstruction, especially in younger, active patients. ^[2]
• High-risk groups (skeletally immature, elite athletes, or those with concomitant meniscal injuries) may benefit from early surgical intervention. ^[2]
• Skeletally immature patients require careful consideration of growth plate status and may need specialized surgical techniques.^[2]