Total knee replacement (TKR), is a surgical technique performed for the knee joint to replace the damaged joint with a prosthetic implant, eliminating structural and functional deficits and realigning the soft tissues. TKR helps to return to normal biomechanics, increases muscle balance, improves the joint range of motion, and decreases pain, it also helps to improve functionality thus improving the quality of life. The time for recovery and the intensity of treatment depends upon surgical technique and the patient’s condition.

• Total knee replacement or bi-compartmental knee replacement.
• Uni- compartmental (partial) knee replacement
• Kneecap replacement (patellofemoral arthroplasty)
• Complex or revision knee replacement.

Fixation Method Used For TKR

1. Cemented: Used for older or sedentary patients.
2. Porous ingrowth: Theoretically, porous ingrowth fixation should not deteriorate with time, unlike cemented fixation, and is thus the ideal choice for younger or more active candidates.
3. Hybrid technique:
   
   • Non-cemented ingrowth femoral and patellar component with a cemented tibial component.
   • Frequently used because of failure to achieve fixation with some of the original porous–coated tibial components.

Disabling knee pain with functional impairment and significant bony changes and failed conservative measures are the indications for TKR, these causes may include:

• Rheumatoid arthritis
• Disabling osteoarthritis
• Knee injury
• Knee deformity
• Gout
• Hemophilia
• Pain and loss of cartilage

Pathology: Total knee replacement is also known as knee arthroplasty, it is the reconstruction surgery of the arthritic or the damaged knee joint. End of the bone is capped by the metal or plastic material. This surgery is done in patients suffering from severe arthritis or knee injury. The joint cartilage and also the surrounded bone of the knee are damaged. There is inflammation of the synovial membrane and increased synovial fluid, this leads to stiffness and severe pain.

X-rays: X-rays help to determine the extent of joint damaged.
MRI: MRI helps to determine the bone, muscular or ligamentous damage.

Medications: Bupivacaine, Tylenol, Oxycontin, Toradol
Note: Medication should not be taken without a doctor’s prescription.

The physiotherapist uses the following techniques and modalities for regaining the functionality of the knee joint.
Cryotherapy: Cryotherapy in combination with PROM exercises, elevation, and massage or compression wrapping is used to decrease edema, developed due to inactivity or loss of voluntary movements.
Thermotherapy: Thermotherapy can be used in combination with ROM exercises (twice daily) with sustained stretching technique (20 – 30minutes).
NMES: Neuromuscular stimulations facilitate voluntary motor control and muscle strength.
Ultrasound: Ultrasound is decreases pain, increases range of motion, and decreases inflammation.
Laser: Cold laser is an effective treatment used for reducing pain thus increase joint range of motion.
Phase 1: Immediate post-operative phase-days 1-10
Goals

• Active quadriceps muscle contraction
• Safe (isometric control), independent ambulation
• Passive knee extension to 0 degrees.
• Knee flexion to 90 degrees or greater.
• Control of swelling, inflammation and bleeding.

Days 1-2

• Weight–bearing with a walker as tolerated.
• Passive range of motion exercise.
• 0-40 degrees as tolerated if stable wound.
• Exercises ankle pumps with leg elevation.
• Passive knee extension exercise.
• SLR if not contraindicated.
• Quad sets.
• Knee extension exercise 90-30 degrees.
• Knee flexion exercises (gentle).

Days 4-10

• Weight-bearing, as tolerated.
• Passive range of motion, 0-90 degrees as tolerated.

Exercises

• Ankle pumps with leg elevation.
• Passive knee extension stretch.
• Active- assisted ROM knee flexion.
• Quad sets.
• SLR
• Hip abduction- adduction
• Knee extension exercise 90-0 degrees
• Gait training
• Continue safe ambulation

Phase 2: Motion Phase – weeks 2-6
Criteria for progression to phase 2.

• Leg control able to perform SLRs
• Active ROM 0-90 degrees
• Minimal pain and swelling
• Independent ambulation and transfer

Goals

• Improve ROM enhance muscular strength and endurance.
• Dynamic joint stability.
• Diminish swelling and inflammation.
• Establish a return to functional activities.
• Improve general health.

Weeks 2-4
Weight-bearing with an assistive device.
Exercises

• Quad sets.
• Knee extension exercise 90-0 degrees.
• Terminal knee extension 45-0 degrees.
• SLR (flexion –extension).
• Hip abduction- adduction.
• Hamstring curls.
• Squats.
• Stretching for hamstrings, gastro- soleus, quads.
• Bed cycling ROM stimulus.
• Continue passive extension stretch.

Weeks 4-6
Exercises

• Continue all exercises listed above.
• Initiate, front and lateral step-ups, front lunge, hydrotherapy.
• Continue compression and elevation for swelling.

Phase 3: intermediate phase- Weeks 7- 12
Criteria for progression to phase 3

• ROM 0-110 degrees.
• Voluntary quadriceps muscle control.
• Independent ambulation.
• Minimal pain and inflammation.

Goals

• Progression of ROM (0-115) degrees and greater.
• Enhancement of strength and endurance.
• Eccentric concentric control of the limb
• Cardiovascular fitness
• Functional activity performance.

Weeks 7-10
Exercises

• Continue all exercises mentioned above.
• Initiate a progressive walking program
• Initiate endurance hydrotherapy exercises.
• Return to functional activities
• Lunges, squats, step-ups (small 2- inch )
• Emphasize eccentric-concentric knee control

Phase 4: Advanced Activity Phase-weeks 14-26
Criteria for Progression to phase 4

• Full, non-painful ROM (0-115 degrees).
• Strength of 4+/5 or 85% of the contra lateral limb.
• Minimal or no pain and swelling
• Satisfactory clinical examination

Goals

• Allow the patient to return to advanced level of function.
• Improve strength and endurance of the lower extremity.
• Return to a normal lifestyle.

Exercises

• Quads set
• SLR(flexion-extesnion)
• Squats
• Hip abduction-adduction
• Lateral steps up
• Knee extension exercise 90-0 degrees.
• Stretching
• Knee extension to 0 degrees
• Knee flexion to 105 degrees
• Initiate gradual walking program, sports activities

• JOint infection
• Deep Vein Thrombosis
• Loosening
• Chronic Pain
• Swelling
• Instability
• Limited range of motion
• Implant rejection
• Bone Fractures
• Nerve damage