Introduction:
Total knee arthoplasty (TKA) or total knee replacement (TKR) is a orthopaedic surgical procedure where the articular surfaces of the knee joint ( the femoral condyles and tibial plateau) are replaced. There is at least one polyethylene piece, placed between the tibia and the femur, as a shock absorber. In 50% of the cases the patella is also replaced. Reasons for a patella replacement include: osteolysis, maltracking of the patella, failure of the implant. The aim of the patella reconstruction is to restore the extensor mechanism. The level of bone loss will dictate which kind of patella prosthesis is placed.
The main clinical reason for the operation is osteoarthritis with the goal of reducing an individuals pain and increasing function.
Clinically Relevant Anatomy
The Knee is a modified hinge joint, allowing motion through flexion and extension, but also a slight amount of internal and external rotation. There are three bones that form the knee joint: the upper part of the Tibia , the lower part of the Femur and the Patella. The bones are covered with a thin layer of cartilage, which ensures that friction is limited. On both the lateral and medial sides of the tibial plateau, there is a meniscus, which adheres the tibia and has a role as a shock absorber. The three bones are kept together by the ligaments and are surrounded by a capsule.
Etiology
When all the compartments of the knee are damaged, a total knee prosthesis may be necessary. The most common reason for a total knee prosthesis is Osteoarthritis . Osteoarthritis causes the cartilage of the joint to become damaged and no longer able to absorb shock. There are a lot of external risk factors that can cause knee osteoarthritis. For example: being overweight; previous knee injuries; partial removal of a meniscus; rheumatoid arthritis; fractures; congenital factors. There might also be some genetic factors the contribute to the development of osteoarthritis, but more research is necessary. Total knee arthroplasty is more commonly performed on women and incidence increases with age.
Characteristics/Clinical Presentation
Pain is the main complaint of patients’ with degenerated knee joints. At first, pain is felt only after rest periods ( this is also called ‘starting pain’) after a couple of minutes the pain slowly fades away. When the knee joint degeneration increases, the pain can also occur during rest periods and it can affect sleep at night. Individuals’ can also complain of knee stiffness and crepitus. Due to pain and stiffness, function can decline and is manifests as reduced exercise tolerance, difficulty climbing stairs or slopes, reduced gait speed and increased risk of falls.
Complications
Stiffness is the most common complaint following primary total knee replacement, affecting approximately 6 to 7% of patients undergoing surgery. 5 of patients have some degree of movement limitation. In addition to stiffness, the following complications can impact on function following this surgery:
- Loosening or fracture of the prosthesis components
- Joint instability and dislocation
- Infection
- Component misalignment and breakdown
- Nerve damage
- Bone fracture (intra or post operatively)
- Swelling and joint pain
Complications as above may require joint revision surgery to be performed.
Diagnostic Procedures
In order to assess the gravity of wear or injury the orthopedic surgeon carries out external tests, and the patient is likely to undergo imaging. Patients co-morbidities also need to be considered Obesity is an important factor that needs to be considered prior to surgery as evidence suggests a correlation between higher body mass index (BMI) and poorer post-operative functional outcomes
These are the different stages of osteoarthritis that you can see at a MRI.
Outcome Measures
- Knee disability and Osteoarthritis Outcome score (KOOS)
- The Timed Get Up and Go Test (TUG)
- Visual Analogue Scale (VAS)
- Range of motion (ROM)
Examination
Subjective Assessment
First the examiner should ask the patient about the history of complaints and also about expectations from surgery.
The examiner should then perform a full objective examination. After this different tests could be carried out to determine whether the patient needs total knee arthroplasty:
- Active ROM
- Passive ROM
- Muscle power
- Functional tasks
Post-operative Tests
- Inspection: of the wound/scar, redness, adhesion of the skin. When infection of the wound is suspected the patient must be referred to an Orthopedic Consultant or an emergency doctor.
- Palpation: post-operative swelling, hypertonia (adductors), pain and warmth.
Medical Management
The purpose of the surgical procedure is to achieve pain free movement again, with full functionality of the joint, and to recreate a stable joint with a full range of motion.
Total knee arthroplasty is chosen when the patient has serious complaints and functional limitations. Surgery takes some 60-90 minutes and involves putting into place a three-part prosthesis: a part for the femur, a part for the tibia, a polyethylene shock absorbing disc and sometimes a replacement patella. A high comfort insert design is chosen to achieve this. The perfect prosthesis doesn’t exist; every prosthesis must be different and the most appropriate size and shape is chosen on a patient by patient basis.
During surgery a tourniquet is sometimes used; this will ensure that that there is less blood loss. However, when a tourniquet is not used, there will be less swelling and less pain.
Physical Therapy Management
Pre-operative
The physical therapist can choose to teach the patient the exercises before surgery in order that the patient might understand the procedures and, after surgery, be immediately ready to practice a correct version of the appropriate exercises. It is also important that the functional status of the patient before surgery is optimised to assist recovery. The focus of a pre-operative training program should be on postural control, functional lower limb exercises and strengthening exercises for both of lower extremities.
Unfortunately, there is limited evidence to support that pre-operative physiotherapy brings significant improvements in patient outcome scores, lower limb strength, pain, range of movement or hospital length of stay following total knee arthroplasty.
Post-operative
Evidence indicates that physiotherapy is always beneficial to the patient post-operatively following total knee arthroplasty. Although specificity of intervention can vary, the benefits of the patient actively participating and moving under physiotherapists’ direction are clear and supported by the evidence. There is also some low-level evidence that accelerated physiotherapy regimens can reduce acute hospital length of stay.
Perhaps the most important role of physiotherapists in the management of patients following TKA is facilitating mobilisation within 48 hours of surgery, sometimes as early as the same day as the operation (Day 0). The use of a continuous passive motion (CPM) may be utilised in this period. A 2011 report found that although clinical outcome measure showed no better results than traditional mobilisation techniques, subjectively patient outcomes of pain, joint stiffness and functional activity were better. The optimal physical therapy protocol should also include strengthening and intensive functional exercises given through land-based or aquatic programs, that are progressed as the patient meets clinical and strength milestones. Due to the highly individualized characteristics of these exercises the therapy should be under supervision of of a trained physical therapist for best results.
There is evidence that cryotherapy improves knee range of motion and pain in the short-term. With are relatively small sample size of low quality evidence, it is difficult to draw solid conclusions regarding the outcomes measured and specific recommendations cannot be made about the use of cryotherapy.”
Common Bed and Chair Exercises:
- Ankle plantarflexion/dorsiflexion
- Isometric knee extension in outer range
- Inner Range Quadriceps strengthening using a pillow or rolled towel behind the knee
- Knee and hip flexion/extension
- Isometric buttock contraction
- Hip abduction/adduction
- Straight leg raises
- Bridging
Physical Therapy Right After Surgery
This may surprise, expect to start PT within a day of the operation.
A physical therapist will come to hospital room and show exercises, start doing right away. its have fresh stitches and a brand-new body part. Trust that the moves are safe, though. They’re designed to:
- Strengthen leg
- Restore knee movement
- Help walk on new knee
Home or Rehab Clinic
Most people spend 1 to 3 nights in the hospital. After discharged, it might check into a rehab facility. There, usually get physical therapy 6 days a week for a couple of weeks. One advantage of a rehab clinic is that will have help and it sure to do exercises every day.
Most people will go straight home. Done right, home PT is just as helpful as in-patient rehab. patient will need in-home physical therapy several days per week for 4-6 weeks.
A third way is to do Physiotherapist at an outpatient rehab clinic. Some people have even the knee surgery itself as an outpatient, without an overnight stay.
Home Care
If patient go home instead of to a rehab clinic, keep these tips in mind:
Help to wound heal. Don’t soak it in water until it’s sealed and healed. advice on when showering after surgery is safe.
Eat right. Even if patient don’t have an appetite after the operation, make sure to eat nutritious foods. patient may also suggest an iron supplement or fiber-rich foods to lower possible problems with medications.
Move new knee. Chances are patient will get a walking plan that starts inside and then takes outside as patient get stronger. On top of that, patient will do PT moves a few times a day at home.
Exercise Schedule
It’s not what most people would call a workout. But PT after knee surgery will make stronger. patient can expect to do 20-30 minutes of PT two or three times a day. patient also may need to walk for half an hour at least a couple of times daily.
Day 1: At the hospital, a physical therapist will guide as patient get out of bed and put weight on patient’s new knee for the first time. patient might even take a few steps with a walker.
The therapist also will help patient with bedside exercises. An example is to tighten your thigh muscles, hold for 5-10 seconds, release, and repeat 10 times. patient will also “pump” his ankles by moving the foot up and down to tighten shin and calf muscles.
Day 2: patient keep doing exercises to strengthen the muscles that support knee. patient will practice bending and straightening his knees, as well as flexing and relaxing thigh muscles. its also walk farther, either with a walker or crutches.
Days 3-5: patient might still be in the hospital, or discharged to a rehab center or back home. he continue with as much PT can handle. With help, patient might even climb some stair steps.
Day 5-week 4: patient slowly ramp up exercises knee gets stronger. During this time, it may:
- Walk farther with walker or crutches.
- Need only a cane or a single crutch to walk. it can do this, can stand for more than 10 minutes.
- Use an exercise bike. At first, pedal backward only. patient can pedal forward when knee is strong enough.
After 4 weeks, physical therapist may suggest that add light weights to add resistance. patient should stick with all recommended exercises for at least 2 full months after the surgery.
Back to Regular Life
patient might drive again as soon as 3 weeks after his surgery. But most people need 4-6 weeks before they can bend their knee to get in and out of the car.
In 3-6 weeks, patient could shop for groceries, get up from a chair, and do other things that were difficult before the surgery.
THOSE ABOVE ARE COLLECTED FROM SOME WEBSITES.
THANK YOU,
SRIKUMARAN PHYSIOTHERAPY CLINIC & FITNESS CENTER
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