This study is a randomized clinical trial comparing standard medial para-patellar total knee arthroplasty with a quadriceps sparing mid-vastus approach. Patients who are medically well and have a good support structure at home will be randomized to a standard or quadriceps sparing surgical approach stratified by type of analgesia (adductor canal block or local infiltration). We will compare patient satisfaction and costs from the perspective of the Ministry of Health, the institution, society and the patient.

Over the past 20 years the length of stay in hospital after total knee replacements has decreased from 9 days to 3 days in Canada and in just the last 10 years the mean length of stay has decreased by half from 6 to 3 days. In order to discharge patients quicker from hospital it's been theorized that less invasive techniques and better, longer lasting anaesthesia are required.

The less invasive quadriceps sparing mid-vastus approach for TKA has been compared to the standard medial para-patellar technique in many studies. Meta-analyses that have looked at studies comparing these approaches have shown some early advantages for quadriceps sparing early post-surgery, but no differences between groups later on and no difference in complications. Early advantages of the mid-vastus approach could potentially allow for earlier and safer discharge from hospital.

Adductor canal block (ACB) and local infiltration analgesia (LIA) form the mainstay of opioid sparing multimodal analgesia for TKA. The nerves of the adductor canal innervate the superficial and deep tissues of the anterior and medial aspects of the knee. ACB has been shown to provide equivalent analgesia while maintaining quadriceps power compared to femoral nerve block (FNB). LIA involves infiltrating the soft tissues of the posterior, lateral and medial aspects of the knee with local anesthetics, ketorolac and morphine. Due to their minimal impact on motor function, ACB and LIA are suitable for fast track TKA.

In combination, quadriceps sparing mid-vastus TKA with ACB may allow patients to be discharged from hospital quicker when compared with standard medial para-patellar TKA with LIA. With our study we aim to investigate whether a quadriceps sparing TKA can provide cost savings without changing complication rates when compared to the current standard of care.

Inclusion Criteria:

• patients requiring primary total knee replacement
• patients willing and able to comply with follow-up requirements and self-evaluations
• patients willing to sign an IRB approved informed consent form
• English fluency (printed instructions are provided in English only)
• varus arthropathy
• osteoarthritis
• ASA less than or equal to 3
• home/cell phone access
• adult to accompany patient home post-operatively and to stay with patient for a minimum period of 1-2 days

Exclusion Criteria:

• patients with inflammatory arthritis
• patients with a BMI greater than 40 or less than 18
• patients who are skeletally immature
• patient with an active infection or suspected latent infection in or about the joint
• bone stock that is inadequate for support or fixation of the prosthesis
• hardware precluding intramedullary instrumentation
• prior osteotomies of the femur or tibia
• patients living greater than 1.5 hours from the hospital
• patients without access to caregivers, or unable to go to their home after surgery
• cognitive or neuromotor conditions
• patient has significant pain management issues
• patient/family history of anaesthesia related complications (e.g. malignant hypothermia, pseudocholinesterase deficiency, airway difficulties, obstructive sleep apnea)
• significant psycho/social issues that would prevent the patient from managing at home safely

Participants will not be told which group they have been assigned to until they have reached the final follow-up visit for the study.