Knee osteoarthritis (OA) is a common musculoskeletal disorder among older people. Since the prevalence of knee OA increases with age, it is anticipated that the prevalence and burden of knee OA will increase significantly given the aging population.

Total knee arthroplasty (TKA) is used to treat patients with severe knee OA. While TKA has been shown to improve knee pain, function and quality of life of patients with knee OA, up to 50% of patients with post-TKA may suffer from falls within in the first year after TKA. Given that Tai Chi can significantly improve the balance and function of older people, a fall prevention program may improve balance, pain, and function of post-TKA patients.

As such, the current 3-arm randomized controlled trial (RCT) aims to compare the effectiveness of a post-operative community-based fall prevention program in improving knee pain, function and balance of patients with unilateral TKA against a group of TKA patients receiving standard post-operative care, and age- and gender-matched asymptomatic controls over 1 year.

Osteoarthritis (OA) is the third most disabling musculoskeletal compliant in the world. Knee OA is the most common type of OA. Since the prevalence of knee OA increases with age, it is anticipated that the prevalence and burden of knee OA will increase significantly given the aging population.

Total knee arthroplasty (TKA) is a surgical intervention for treating patients with severe knee OA. Research has found that TKA reduces knee pain, and improves patient's function and quality of life. However, studies have also found that patients with post-TKA may be more likely to fall as compared to age- and gender-matched asymptomatic counterparts. It is estimated that around 20% to 50% of patients fall within in the first year after TKA. As such, it is essential to improve the balance of post-TKA patients.

Studies have found that Tai Chi can significantly improve the balance and function of older people. Therefore, a fall prevention program aiming at strengthening, proprioception, balance training, and behavioral modification may improve balance, pain, and function of post-TKA patients.

As such, the current 3-arm randomized controlled trial (RCT) aims to compare the effectiveness of a post-operative community-based fall prevention program in improving knee pain, function and balance of patients with unilateral TKA with a group of patients receiving standard post-operative care, and age- and gender-matched asymptomatic controls over 1 year.

Inclusion Criteria:

• Participants undergoing TKA for intervention group and usual postoperative care group
• Age- and gender-matched asymptomatic controls without knee pain in the last 12 months.
• Can speak and understand Cantonese/English.

Exclusion Criteria:

• Living in assisted living facilities, requiring nursing care
• Medical 'red flag' conditions
• A history of cancer in the last five years
• Cauda equine syndrome
• Knee fracture
• Auto-immune disease (e.g. rheumatoid arthritis) even if they have OA
• Inflammatory or septic arthritis
• Systemic disease
• Amputation
• History of orthopedic or neurological surgery to the spine, pelvis or hips
• Neurological diseases (e.g. stroke or Parkinson's disease)
• Mini-Mental State Examination score < 24
• Depression subscale score of Depression Anxiety Stress Scales > 21
• Severe comorbidity leading to severe deterioration of quality of life or major healthcare utilization
• Osteochondritis dissecans
• Perthes' disease
• Plica disease
• Baker's cyst

The orthopedic surgeons, outcomes assessor and statistician will be blinded.