1. Total Knee Replacement

2. Contents General anatomical overview What is TKR
Knee implant components
Types of knee joint prosthesis
Implant materials
material criteria
Cemented and Cementless Implants
Benefits of knee replacement surgery
Indications for TKR

3. Risk factors leading to TKR
Diagnosis
Contraindications for TKR
TKR surgical procedure
Surgical technique
Complications after Surgery
Rehabilitation Exercise Protocols
Home exercises
Precautions after TKR

4. Knee joint General anatomical overview

5. Knee replacement surgery involves
replacing some or all of the components
of the knee joint with a synthetic implant,
to repair the damaged weight-bearing surfaces that are causing pain.
A total knee replacement surgery replaces all three compartments of the diseased knee joint. A partial knee replacement involves an implant in just one or two compartments of the knee, retaining any undamaged parts.

6. Knee implant components
Up to three bone surfaces may be replaced in a total knee replacement:
The lower ends of the femur.
The top surface of the tibia.
The back surface of the patella.
* helps improve outcomes and pain free functions

7. Posterior-Stabilized Designs
Cruciate-Retaining Designs
Unicompartmental Implants

8. Types of knee joint prosthesis
Fixed-Bearing Prosthesis
Mobile-Bearing Prosthesis

9. Implant Materials
Metal parts of the implant: made of titanium or cobalt- chromium based alloys.
Plastic parts: made of ultra high molecular weight polyethylene.
All together, the components weigh between 15 and 20 ounces, depending on the size selected.

10. Material Criteria
They must be biocompatible; should not be creating a rejection response.
Strong enough to take weight bearing loads
Able to move smoothly against each other as required.
Able to retain their strength and shape for a long time.

11. Cemented and Cementless Implants
Cemented fixation: uses a fast-curing bone cement (polymethylmethacrylate).
Cobalt-chromium alloy femur articulating with standard polyethylene tibial surface is most common
Cementless fixation: relies on new bone growing into the surface of the implant for fixation.
Cementless implants are made of a material that attracts new bone growth.
Most are textured or coated so that the new bone actually grows into the surface of the implant.

12. Hybrid fixation: for total knee replacement, the femoral component is inserted without cement, and the tibial and patellar components are inserted with cement.

13. Benefits of knee replacement surgery
Elimination of pain.
Improved range of motion.

14. Indications for TKR Osteoarthritis Rheumatoid arthritis
Trauma: Damage to the knee from a fall, automobile accident, or workplace or athletic injury

15. Risk factors leading to TKR
Genetic: Both OA and RA tend to run in families.
Age: Knee cartilage becomes thinner and weaker.
Sex: Women athletes have three times as many knee injuries as men.
Biomechanical: Certain types of leg or foot deformities, such as bowlegs or difference in leg length, are at increased risk of knee disorders because the stresses on the knee joint are not distributed normally.

16. Gait-related factors: Irregular walking patterns .
Shoes: High heels, Poorly fitted or worn-out shoes contribute to knee strain by increasing the force transmitted upward to the knee when the foot strikes the sidewalk or other hard surface.
Work or other activities that involve jumping, jogging, or squatting: Tends to loosen the ligaments that hold the parts of the knee joint in alignment

17. Diagnosis Patient history
General medical history, but also about the patient's occupation, exercise habits, past injuries to the knee, and any gait-related problems and patient's ability to move or flex the knee
Diagnostic tests
Physical examination of the knee: signs of inflammation, abnormal postures, gait abnormality and ROM

18. Imaging studies
X-ray, CT Scan or MRI
Aspiration
Blood in the fluid usually indicates a fracture or torn ligament; the presence of bacteria indicates infection; the presence of uric acid crystals indicates gout. Clear, straw- colored fluid suggests osteoarthritis.
Arthroscopy
Drain fluid from the knee. Sterile saline fluid is pumped into the knee to enlarge the joint space and make it easier for the surgeon to view the knee structures and to cut, smooth, or repair damaged tissue.

19. Contraindications for TKR
Knee sepsis
A remote source of ongoing infection
Extensor mechanism dysfunction
Severe vascular disease
Recurvatum deformity secondary to muscular weakness
Presence of a well-functioning knee arthrodesis

20. Skin conditions within the field of surgery (eg, psoriasis)
Past history of osteomyelitis around the knee
Neuropathic joint
Obesity

21. TKR surgical procedure

22. Surgical technique Minimally invasive TKA
Shorter incision
Quadriceps sparing
Early, limited results:
Better ROM
Less blood loss
Shorter LOS
Less need for assistive
devices at 2 weeks post-op

23. Complications after Surgery
Infection
Blood clot/deep vein thrombosis
Implant loosening
Implant breakage- The most common components to break are the plastic tibial, or shinbone, spacer and the patella, or kneecap, implant, which is also plastic.
Excessive joint stiffness

24. Rehabilitation Exercise Protocols
Pre.op (1-2 weeks prior to surgery)
Education on the surgical process and outcomes
Instruction on a post. op exercise program
Assessment of the home environment

25. Post. Op day 1
Bedside exercises: ankle pumps, quadriceps sets, gluteal sets
Review of weight bearing status
Bed mobility and transfer training: bed to/from chair

26. Strengthening exercises:
Post. op day 2
Exercises for active ROM, AAROM, and terminal knee extension
Strengthening exercises:

27. Gait training with an assistive device and functional transfer training: sit to/from stand, toilet transfers bed mobility

28. Post .op day 3-5/on discharge to the rehabilitation unit
Progression of ROM and strengthening exercises to the patient tolerance
Progression of ambulation on level surfaces and stairs (if applicable) with the least restrictive device
Progression of ADL training

29. Post. op day 5- 4 weeks
Strengthening exercises: long arc quads/seated leg extension, standing hip abduction and extension, knee bends, short arc quads
Strengthening of quadriceps and hamstring muscles
progression of ambulation distance
Progression of independence with ADL

30. Treatment Category Specifics Therapeutic Exercise
Endurance conditioning or reconditioning; Balance, coordination, and agility training; Body mechanics and postural stabilization; Flexibility exercises; Gait and locomotion training; Relaxation; Strength, power, and endurance training for head, neck, limb, pelvic-floor, trunk, and ventilatory muscles
Functional Training
ADL training; Devices and equipment use and training; Functional training programs; IADL training; Injury prevention or reduction; Leisure and play activities and training
Electrotherapeutic Modalities
Biofeedback; Electrical Stimulation — EMS, FES, high voltage pulsed current (HVPS), NMES, TENS
Physical Agents and Mechanical Modalities
Cryotherapy — cold packs, ice massage, vapocoolant spray; Hydrotherapy — whirlpool tanks, contrast bath, pool; Sound Agents — phonophoresis, ultrasound; Thermotherapy — dry heat, hot packs, paraffin baths; Mechanical Motion Devices — CPM
Manual Therapy
Massage — connective tissue massage, therapeutic massage; Mobilization/Manipulation — soft tissue; Passive Range of Motion

31. Home exercises Quadriceps sets Ankle pumps Straight leg raises
Supported leg raise
Prone knee flexion
Standing knee curls
Stepups
Stationary cycling

32. Precautions after TKR
Do not attempt to do these exercises unless your doctor or physical therapist has given consent to do so
Doing advanced exercises too early in your rehabilitation can damage the prosthesis as well as set your recovery back
Avoid exercises that are not prescribed by your doctor, especially those that place excessive pressure on the knee joint, such as lunges or squats.

33. Sports & activity recommendations
Knee Society recommendations:
Suitable: cycling, swimming, low-resistance rowing, walking, hiking, low-resistance weight-lifting, ballroom dancing, square dancing
Suitable but more risky: downhill skiing, ice-skating, speed walking, hunting, low-impact aerobics, volleyball
Avoid: Baseball, basketball, football, hockey, soccer, high- impact aerobics, jogging, parachuting, power-lifting