Very well known but commonly taken for granted joint of the human body is ‘knee joint’. A good working knee joint is essential for mobility. It is important to know & understand the basic anatomy of the knee before learning problems occurring in this joint. Bones, joints,ligaments, muscles, tendons, nerves, blood vessels are the main components of this joint.

A) Bones are the part of human skeletal system provides structure, stability, protection and support to the body. The knee joint is form by 4 bones i.e. Femur, Tibia, Fibula & Patella.

B) The knee is a combination of 4 joints,namely, Tibio-Femoral, Patellofemoral & Tibiofibular joint.

C) Ligaments attach bone to bone & help all bones to stay together & also prevent hyper-mobility of joint.

D) Tendons attach muscle to bones & helps in the movement. Major muscle groups that are working on knee are quadriceps (anterior thigh) include 4 muscles, hamstrings (posterior thigh) include 3 muscles & adductors (inner thigh).

E) The extensor mechanism of knee involves patella bone which works with quadriceps tendon as a fulcrum to reduce stress over the tendon while extending the knee.

F) Articulating cartilage covers all the bony ends of the joint that allows the joint surfaces to move against one another without damaging either bone.

Function of it along with meniscus is to absorb shocks and provide smooth surface to carry out motion. Also synovial fluid is synthesized by cartilage.

G) The knee gets it’s lubrication from synovial fluid.

H) Bony articulating surfaces,cartilages, meniscus, labrum along with some ligaments and synovial fluid are enclosed in the joint capsule.


It is the most common type of arthritis. Most commonly occurs during older age. It’s a normal aging process due to wear & tear of the joint structures. It is classified as mild, moderate & severe. It can affect many parts of the body but very commonly seen in knee.

In a healthy knee, the articular cartilage is smooth & the synovial fluid is viscus, both aids in smooth joint movement. Overtime, osteoarthritis affects bones,cartilages and synovial fluid of the knee.

A) With mild knee osteoarthritis, patient begins to feel mild discomfort. During this the joint space appears normal but the cartilage begins to break down from wear and tear. Also osteophytes begin to form at the edges of the joint.

Osteophytes are the small, smooth, dance growth of bone which is body’s response to loss of cartilage. Progression can be slowed by loss of weight & exercises.

B) With moderate knee osteoarthritis, the cartilage between the bones begins to erode which reduces joint space. Synovial fluid synthesis is reduced so that it becomes less viscous, concentrated and elastic. Osteophytes increases in number & size making the articulating surface rougher. All these factors increase joint pain both with movement and rest. During this period weight loss, exercises, pain killers & injections are prescribed.

C)    With severe osteoarthritis, condition worsens dramatically. The joint space is now far narrow causing more rapid & severe destruction of the cartilage. Knee becomes inflamed & sore.This & decrease in synovial fluid increases friction in joint surfaces during movements. This also degrades soft tissues around the knee. Treatment at this stage is typically surgery by partial or total knee replacement. 

Knee Replacement Surgery

This surgery is a procedure in which painful and poorly functioning, knee joint is replaced with artificial components. This is recommended only if your knee is severely damaged by osteoarthritis or injury.

Procedure of surgery

Your surgeon gains the access of your knee by separating soft tissues around it. Using specialized tools surgeon will remove damaged bone and cartilage. Then the artificial components of the knee are positioned.

Role of physiotherapy in knee replacement

As we discussed earlier knee replacement is done when patient’s knee joint (bones & soft tissues) are damaged beyond repair. So role of physiotherapy, both before and after surgery is much more important now.

Physiotherapy management is mainly divided into:

- Pre operation i.e. pre-op

- Post operation i.e. post-op

- Follow up

A) Pre-op physio management

a) Maintain available ROM (range of motion) 

To get maximum benefit out of surgery, you 1stshould have to maintain available joint range, gain little bit of muscle strength & understand the movement pattern.

b) Decrease pain and swelling

During pre-op period, there is no implant present in the joint. So physiotherapist can apply electrotherapy and ultrasound therapy on the joint to reduce pain intensity and swelling.

c) Guide about post op exercises

As anaesthesia wears off post surgery, patient will definitely be facing some amount of pain and discomfort in the joint. So if it is necessary for you to know and practice initial exercises prior to surgery. It will help to avoid wastage of time and energy later.

d) Posture correction and ADL advice

Many times (actually most of the times) the origin of knee pain is because of poor postural alignment and faulty ADL (activities of daily living) habits. So it iscurtail to avoid those habits after surgery. A wise man once said, “You can never change the result by doing same thing over and over again in a same way”.

e) Assistive device training

Many patients do not use assistive devices (walker, sticks, etc) before surgery while walking. So training of those prior to surgery and practicing it will reduce stress while doing post op rehab. 

B) Post op physio management

a) Improving ROM ( range of motion)

Due to stiffness of joints in pre op stage all the soft tissues becomes tight which decrease joint ROM. Improvement can be done by Physio’s manual efforts as passive movements, stretching or with CPM machine.

b) Decrease pain and swelling

We avoid applying electrotherapy devices directly over implants. So for pain relief, initially we use ice & exercise and HWF in later stage.

c) Scar mobility

After stitches are removed, many times adherent scar tissues are form in the operation wound which tightens the skin and fascia and causes reduction in ROM.

d) Muscle training and strengthening

Many exercises are gradually introduced to patient by physiotherapist as per the muscle groups we need to strengthen.

e) Gait training

Gait means training of walking. Walking looks & feels very simple task while we have normal working joints. But in reality walking needs major co-ordination between many systems of the body such as musculoskeletal system, vestibular system, proprioceptor, balance, eye-ear co-ordination, etc.

So training to walk is a major challenge after surgery. Physios will make sure to train patients for all the challenges they will face later in life.

f) Balance and proprioception training

Proprioceptors are the receptors present in all joints which tell brain that where exactly is that joint at that particular time around space even when one can’t see it with their eyes. Balance is the main skill you need to acquire if you want to without any difficulty.So training of both is curtail during rehabilitation.

Recovery & rehab after TKR

 For a rapid recovery patient need to work with physiotherapist to run the exercise programs much before the surgery. When one is aware what can be done after the surgery well before surgery reduces the anxiety & makes the patient more comfortable post surgery rehab program.

With modern surgical procedures & implants, the rehab starts within 2 hours after the surgery. This is the first part of the rehab which is to gain flexibility.Now 2nd part is to gain strength which requires efforts from patient’s side. The desired effects can occur within 4 -6 weeks after surgery with the help of physiotherapy.

Patient can walk independently within a week & work independently soon after removal of stitches.

Always remember: You are the center of your recovery!

To get your knee pain assessed or to know what the stage of your osteoarthritis knee is, book a appointment with a doctor now.