Knee joint: Basic structure

Healthy knee joint:

  • Knee joint is formed by the thigh bone (Femur) and shin bone (tibia).
  • Knee cap (Patella) lies in front of the knee joint.
  • Knee joint is lined by tissue called Synovium which secretes fluid called Synovial fluid. It aids in lubrication of joint.
  • The ends of thigh bone and shin bone are covered by Cartilage which provides a cushion for smooth movement of knee joint.
  • Joint capsule and ligaments around the knee joint provide stability and strength.

Arthritic knee / damaged Knee

  • When the cartilage lining of normal joint wears or gets worn out it may result in pain and stiffness in the knee

The cartilage may be damaged by

  • Ageing: a result of natural wear and tear which is termed as Osteoarthritis of knee.
  • Injury / fractures around knee joint.
  • Diseases like Rheumatoid arthritis, gout etc
  • In some individuals genetic factors may also predispose to early damage to cartilage.

How will total knee replacement help you ?

  • Improvement of quality of life
  • Improve range of motion
  • Pain free life

Getting ready for Knee replacement surgery:

  1. Medical evaluation:  
  2. Cardiac evaluation:
  3. Tests:Lab tests include Blood, urine and cardiac tests.
  4. Preparing your knee: Surgeon examines your knee prior to the surgery. There should be no skin infection, wounds around the knee and skin should be clean.
  5. Others:
  6. Anaesthtic evaluation:  after getting all the blood tests and cardiologist opinion you will be examined by anaesthetist. He will evaluate you and gives you fitness for giving anaesthesia and advice's different modalities of pain relief during postoperative period.

SURGERY:

On the day before surgery:

  • You will be admitted inthe hospital or asked to come directly to the hospital on the planned day ofsurgery.
  • You need to take themedications for you blood pressure and diabetes.
  • You should have lightdinner without much oil and spices and plenty of water. You should startfasting from 11PM on the day before surgery till further advice.
  • You should give consentand sign an informed consent.
  • Follow you anaesthetistand surgeons orders if any given to you in writing.
  • Have a neat shower.

On the day of surgery:

  • You should be onfasting, take your regular blood pressure and thyroid medications if any withsips of water at around 6 AM.
  • You can have a plainshower bath
  • Limb to be operatedwill be marked by the surgeon.
  • You will be shifted tooperation theater half hour prior to surgery.
  • Anaesthetist willevaluate once again and prepares you for giving you anaesthesia.

Anaesthesia:

Most of the knee replacement surgeriesare carried under spinal anaesthesia. In rare cases when a patient is not fitfor spinal anaesthesia, Knee replacement is performed under generalanaestheisa.

Postoperative pain relief is achieved bycontinuous Lumbar epidural pump or continues Femoral block pump.

TOTAL KNEE REPLACEMENT SURGERY:

It is a surgical procedure in which thedamaged lining of the knee joint is replaced with metallic lining and plasticcushion to aid smooth movement.

Surgical procedure:

  • The damaged cartilageand bone of lower end of thigh bone (Femur) is replaced by similarly shapedmetal shell.
  •  Similarly damaged cartilage and bone of upperend of shin bone (Tibia) is replaced by metal plate with plastic cushion.
  • These metallic surfacesare fixed to bones with the help of bone cement.
  • In some conditions when the lining of the knee cap is also damaged it may also be replaced with plastic button.

RECOVERY IN HOSPITAL:  POSTOPERATIVE PERIOD

First 24 hours:

  • Immediately after knee surgery you would be shifted to ICU (intensive care unit) and observed for at least for 24 hours.
  • After a day you will beshifted to ward of your choice.

Firs postoperative day:

  • On the bed you are advised to perform deep breathing exercises.
  • Ankle pump and static quadriceps exercises on the bed.
  • Gentle mobilization on bed with legs hanging down the bed and knee movement exercises.
  • If you are strong enough you would be made to stand and even walk with the help of walker.
  • You will be shifted toward.

Second Postoperative day:

  • To continue the exercises on bed and walking with help of walker.
  • Drain tubes urinary catheter will be removed on the second day.
  • You need to take plenty of fluids and regular diet.

Third Postoperative day :

  • Depending on speed of your recovery discharge would be planned.
  • The bulky dressing on the knee is changed to simple dressing.
  • You are advised to continue exercises and walking, gradually increasing the pace.

Fourth postoperative day:

  • Some patients with slow recovery are discharged on 4th postoperative day.

Before you are discharged from the hospital, you will be helped to achieve:

  • Getting in and out of the bed independently.
  • A good progress in bending your knee or to achieve approximately 90 degrees.
  • Straightening your knee completely.
  • Walking with the help of walker and climbing up and down the stairs.

DISCHARGE ADVICE:

RECOVERY AT HOME

 You should continue to stay active when you are at home for full recovery. However remember not to overdo it. You will observe gradual improvement and increased endurance over the next 6 to 12months.

Tips to make you return home comfortable:

Planning your work:

You will be able to walk on crutches or a walker soon after surgery. But you will need help for many weeks with tasks like cooking, shopping, bathing and doing laundry. Make advance arrangements to have someone assist at home.

Home planning:

Before going for surgery, follow the steps given below to make your recovery at home easier.

  • Fix safety bars in your shower or bathroom.
  • Secure your stairways for support and safety.
  • Keep a stable chair, for your early recovery period, with firm cushion, firm back, two arm, and footstool for leg elevation.
  • If you have low toilet seat, fix a seat raiser with arms.
  • Walking up or down the stairs within you pain limits and depending on your recovery.

DO’SAND DONT’S DURING YOUR RECOVERY

DO’S

  • Keep the wound are clean.
  • If your wound appears red or begins to drain, inform your doctor.
  • Check temperature regularly and inform your doctor if it exceeds above normal
  • If you observe swelling, elevate your leg slightly with support and apply ice- packs over the swelling intermittently.
  • Inform your doctor immediately if you have calf pain, chest pain, or shortness of breath.
  • Do mild exercises(physical therapy)
  • Practice / initiate regular walking using crutches or walker.
  • Perform exercises to strengthen calf and thigh muscles.

DONT’S

  • Do not play high impact sports.
  • Do not jog, run or jump.
  • Avoid gaining weight as it can hasten wear and tear of the implant.
  • Do not shower or bath until the sutures are removed.