Knee Replacement Physiotherapy: Week-by-Week Recovery

Introduction to Knee Replacement Recovery

Total knee arthroplasty (TKA), commonly referred to as total knee replacement, is a highly successful surgical procedure designed to alleviate severe pain and disability caused by advanced knee osteoarthritis or joint damage. However, the success of the surgery depends heavily on a structured post-surgical rehabilitation program. Dedicated physiotherapy is crucial to prevent joint stiffness, restore normal biomechanics, and rebuild muscle strength. This comprehensive guide outlines the week-by-week recovery milestones, exercises, and clinical protocols required to achieve optimal long-term outcomes.

Phase 1: Weeks 1–2 (Acute Healing & Joint Mobility)

The primary clinical goals during the first two weeks post-surgery are controlling pain and swelling, preventing deep vein thrombosis (DVT), and initiating early joint range of motion. During this acute phase, patients must focus on achieving full knee extension (0 degrees) to prevent a permanent flexion contracture, which can lead to a limp.

Critical Goals

• Achieve 0° of passive knee extension and at least 90° of flexion.
• Manage swelling using the R.I.C.E. protocol (Rest, Ice, Compression, Elevation).
• Achieve safe, independent transfers (getting in and out of bed and chairs).
• Walk safely with an assistive device (walker or crutches) on flat surfaces.

Recommended Exercises

1. Ankle Pumps: Move feet up and down repeatedly (20 reps every hour) to promote blood circulation and reduce DVT risk.
2. Isometric Quad Sets: Contract the thigh muscle by pushing the back of the knee down into the bed. Hold for 5 seconds, relax, and repeat for 15 repetitions, 3 times daily.
3. Heel Slides: Gently slide the heel toward the buttocks to bend the knee within a pain-free range. Perform 10-15 repetitions to improve flexion.
4. Straight Leg Raises: Lock the knee straight and lift the leg 12 inches off the bed. Hold for 2 seconds and lower slowly. This builds early hip and quad control.

Phase 2: Weeks 3–4 (Strength Building & Gait Retraining)

As the surgical incision heals and acute pain subsides, the focus of physiotherapy shifts to progressive muscle strengthening and gait normalization. Patients typically transition from a walker to a cane or walk independently during this period.

Milestones & Progressions

• Improve knee flexion range of motion to 105° or greater.
• Normalize walking patterns, focusing on heel-strike and toe-off phases of gait.
• Discontinue using crutches or a walker in favor of a single-point cane, if cleared by the physical therapist.
• Begin active-assisted extension stretching to maintain full terminal extension.

Key Rehabilitation Exercises

• Long Arc Quads: Sit in a chair and slowly extend the knee straight. Hold for 2 seconds, then slowly lower. Perform 3 sets of 10 repetitions.
• Standing Mini-Squats: Hold onto a stable counter and perform shallow squats (0-30 degrees of bend), keeping knees aligned over toes. Complete 2 sets of 15 repetitions.
• Clamshells: Lie on the side with knees bent and feet together. Slowly raise the top knee to activate the hip stabilizers (Gluteus Medius). Complete 3 sets of 15 repetitions on each side.

Phase 3: Weeks 5–8 (Functional Independence & Cardiovascular Conditioning)

During this phase, rehabilitation advances to functional closed-kinetic chain exercises. These movements replicate daily activities like climbing stairs, getting up from low surfaces, and walking on uneven ground.

• Knee ROM Goal: Flexion should exceed 115° to 120°.
• Gait: Independent walking without assistive devices for moderate distances (15-20 minutes).
• Cardiovascular Work: Begin low-resistance stationary cycling (15-20 minutes) to improve joint lubrication and aerobic fitness.
• Advanced Strength: Introduce step-ups (leading with the operated leg going up, and the non-operated leg coming down) and lateral step-downs under the guidance of a therapist.

Phase 4: Weeks 9–12 and Beyond (Return to Active Living)

By week 9, the new knee joint is highly stable, and the soft tissues are well-healed. Rehabilitation now focuses on advanced balance training, muscular endurance, and returning to recreational activities like golf, hiking, swimming, or cycling.

Week-by-Week Recovery Comparison Table

| Recovery Phase | Typical Timeline | Target Knee ROM | Primary Exercises | Assistive Device Status | | :--- | :--- | :--- | :--- | :--- | | Phase 1: Acute Healing | Weeks 1 - 2 | 0° Extension, 90° Flexion | Ankle pumps, Isometric quad sets, Heel slides | Walker or dual crutches | | Phase 2: Muscle Re-education | Weeks 3 - 4 | 0° Extension, 105° Flexion | Long arc quads, Standing mini-squats, Clamshells | Single crutch or cane | | Phase 3: Functional Loading | Weeks 5 - 8 | 0° Extension, 120° Flexion | Step-ups, Stationary cycling, Balance drills | Independent walking | | Phase 4: Return to Sport/Life | Weeks 9 - 12+ | Full ROM (0° - 125°+) | Leg presses, Propriocetive training, Swimming | Independent walking |

Potential Complications and Prevention

While total knee replacement is generally safe, patients must remain vigilant for potential complications. The most serious risk is deep vein thrombosis (DVT), which presents as severe calf swelling, warmth, and redness. Another risk is arthrofibrosis (severe joint scarring), which can freeze the knee joint in a bent position. Consistent compliance with knee replacement physiotherapy exercises and maintaining regular follow-ups at a neurological rehabilitation or orthopedic clinic are the most effective ways to prevent these complications.