Challenge CR

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 32

Inclusion Criteria

Inclusion criteria for patients undergoing CR TKA:
• Non-inflammatory knee osteoarthritis, which is confirmed by radiology (Kellgren & Lawrence = 2).
• Set to receive a primary cemented total knee arthroplasty.
• Age between 40 and 80 years, inclusive, on the day of the operation.
• In stable health (ASA-score = 3) and is free of or treated for cardiac, pulmonary, haematological, or other conditions that would pose excessive operative risk.
• Patient has a correctable or <10° rigid (non-correctable) varus or valgus deformity of the knee.
• Participants must be able to give informed consent.

Inclusion criteria for healthy controls:
• Age between 40 and 80 years, inclusive, on the day of the baseline measurement.
• In stable health (ASA-score = 3)
• Participants must be able to give informed consent.

Exclusion Criteria

Exclusion criteria for patients undergoing CR TKA:
• BMI > 35.
• Patient has had major, non-arthroscopic surgery to the study knee, including high tibial osteotomy.
• Patient has an active, local infection or systemic infection • Prior high-energy trauma to the affected knee or prior history of posterior cruciate ligament rupture.
• Suspicion of posterior cruciate ligament rupture at clinical examination.
• Incomplete or insufficient tissue surrounding the knee.
• Severe damage to any knee ligament other than the anterior cruciate ligament
• Documented osteoporosis with patient in active medical treatment.
• Patient has physical, emotional or neurological conditions that would compromise compliance with post-operative rehabilitation and follow-up.
• Bone quality compromised by disease or infection which cannot provide adequate support and/or fixation to the prosthesis • Fixed flexion deformity >10 degrees (passive extension lag)
• > 30 degrees extension deficit (active restraint to extension)
• Patient does not have a proper functioning patella tendon on the affected side measured as inability of active extension of the knee
• Impaired extensor strength defined as MRC Grade < 4.
• Undergone patellectomy in the knee receiving CR-TKA
• Moderate to severe knee pain in the contralateral knee defined as an average score of >4 on items 3-6 of the Short Brief Pain Inventory
• Moderate to severe hip or ankle pain defined as an average score of >4 on items 3-6 of the Short Brief Pain Inventory
• Previous knee, hip or ankle replacement surgery, or is planned to have a knee (contralateral), hip or ankle replacement in the next 12 months.
• Any musculoskeletal or neurological disease, or uncorrected visual impairment other than osteoarthritis that impairs gait or balance.

Exclusion criteria for healthy control subjects:
• Moderate to severe knee pain in one or both knees defined as an average score of >4 on items 3-6 of the Short Brief Pain Inventory
• Moderate to severe hip or ankle pain defined as an average score of >4 on items 3-6 of the Short Brief Pain Inventory
• Previous knee, hip or ankle replacement surgery, or is planned to have a knee, hip or ankle replacement in the next 24 months.
• Any musculoskeletal or neurological disease, or uncorrected visual impairment other than osteoarthritis that impairs gait or balance.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Daily-life gait speed<br><br>Note: we will need to explore further analysis options to take gait bout length into account when evaluating daily-life gait speed given their semi-linear relationship. <br>

Secondary Outcome Measures

Name	Time	Method
Perturbations (both anteroposterior and mediolateral):<br>- xCoM excursion (during perturbed and subsequent steps)<br>- Margin of stability<br>- Foot placement<br>- Spatiotemporal gait parameters (step width, step length, step time)<br><br>Up/downhill walking:<br>- Sagittal knee angles<br>- Trunk motion<br>- Spatiotemporal gait parameters<br>