Total Knee Replacement (TKR)
A total knee replacement (TKR) or total knee arthroplasty is a surgery used to replace a knee joint that is affected by arthritis.
Total Knee Replacement surgery replaces the arthritic knee joint with an artificial metal or plastic replacement parts called the 'prostheses'. These include replacing the:
- End of the femur (thigh bone)
- End of the tibia (shin bone)
- Plastic inserted between them and
- Usually the patella (knee cap).
The artificial knee joint is made from a surgical-grade metal alloy with a special wear resistant plastic insert. Total Knee Replacement surgery are one of the most successful operations available today with over 90% still functioning well at 15 years.
Prior to surgery you will usually have tried some conservative treatments such as simple analgesics, weight loss, anti-inflammatory medications, modification of your activities, canes, or physical therapy.
Once these have failed it is time to consider surgery.
Candidates for Total Knee Replacement
The procedure is usually recommended for older patients who suffer from pain and loss of function from arthritis and have failed results from other conservative methods of therapy.
Each patient is assessed individually but Total Knee Replacement candidature is far greater than partial knee replacement and can include candidates who are:
- Between 20 to over 80 years of age
- Suffering pain
- Restricted mobility interferes with your lifestyle
The outcome of the surgery can address patients with a greater range of arthritic stages and conditions.
Benefits of Total Knee Replacement Surgery
The decision to proceed with TKR surgery is a cooperative one between you, Dr Biggs, family and other medical professionals.
The benefits following surgery are relief of symptoms of arthritis. These include
- Severe pain that limits your everyday activities including walking, shopping, visiting friends, getting in and out of chair, gardening, etc.
- Pain waking you at night
- Deformity- either bowleg or knock knees
The benefits are that older patients or severe arthritic patient have a clear solution to help relieve symptoms and pain.
The artificial knee joint consists of:
- An upper metal component shaped and sized to fit to femur bone contour
- A flat metal tibial component made of metal alloys fixed to the bone
- A plastic insert designed to bear significant wear
- A patellar button which resurfaces the back of your knee cap.
Total Knee Replacement Procedure
The procedure is designed to be performed with minimal local trauma
- Dr Biggs cuts down to the bone to expose the bones of the knee joint.
- The damaged portions of the femur and tibia are then cut at the appropriate angles using specialized jigs.
- Trial components are then inserted to check the accuracy of these cuts and determine the thickness of plastic required to place in between these two components.
- The patella (knee cap) may be replaced depending on a number of factors and Dr Biggs’s choice.
- The real components are then inserted with or without cement and the knee is again checked to make sure things are working properly.
- The knee is then carefully closed and drains usually inserted, and the knee dressed and bandaged.
Each knee is individual and knee replacements take this into account by having different sizes for your knee. If there is more than the usual amount of bone loss, sometimes extra pieces of metal or bone are added.
Preparations Prior to Replacement Surgery
Once Dr Biggs decides that surgery is required, preparation is necessary to achieve the best results and a quick and problem free recovery.
Preparing mentally and physically for surgery is an important step toward a successful result.
- Dr Biggs will create a treatment plan and
- Patients will also need to understand the process and their role in it
Dr Biggs will also need to:
- Discuss any medications being taken with your doctor or physician to see which ones should be stopped before surgery
- Stop taking aspirin, warfarin, anti-inflammatory medications or drugs that increase the risk of bleeding one week before surgery to minimise bleeding
- Review blood replacement options (including banking blood) with your doctor
- Consider alternate medical interventions and other treatments
- Eat a well-balanced diet, supplemented by a daily multivitamin with iron.
- Consider losing weight (if overweight) before surgery to help decrease the stress on the new joint. However, dieting one month before surgery.
- Stop or cut down smoking to reduce your surgery risks and improve your recovery
- Treat any tooth, gum, bladder or bowel problems before surgery to reduce the risk of infection
Report any infections to Dr Biggs prior to surgery as the procedure cannot be performed until all infections have cleared up.
To help prepare you for the surgery a preoperative physiotherapist appointment is required to:
- Fit crutches (which should be brought to hospital)
- Instruction on partial weight-bearing crutches useage
- Learning how to reduce inflammation (icing of the knees), and
- Learn postoperative exercise (co contractions, leg lifts with the knee extended, etc).
Risks of Knee Surgery
As with any major operation, orthopaedic surgery has potential risks and complications. Surgical complications may include:
- Stiffness of the knee
- Rerupture of the graft.
- Blood clots
- Damage to local tissue
Dr Biggs will discuss any concerns you may have before any procedure.
After Your Replacement Surgery
After your operation you will have a drip in your arm for pain medication and antibiotics.
You may need between 1 - 3 nights in hospital.
Crutches are required for 1 – 2 weeks following the replacement. Once you are off crutches, you can begin driving.
If any postoperative problems arise with your knee, such as redness, increasing pain or fevers, do not hesitate to contact Dr Biggs. If unavailable, seek advice from the hospital or your doctor.
Going Home After Replacement Surgery
Going home remember to arrange for someone to take you home, no driving is recommended.
Return to Work
You may return to light work duties after 1-2 weeks. You will not be fit to perform work duties that involve:
- Prolonged standing,
- Heavy lifting,
- Bending or
- Excessive stair climbing
for a minimum of 4 – 6 weeks.
Postoperative Recovery Plan
Recovery from Knee Replacement Surgery will usually take about 8 weeks.
The physiotherapist will prepare an exercise programme.
The following is my post op programme following ACL hamstring (autograft) reconstruction and should be placed there
- Ice your knee as directed by your physiotherapist
- Full extension (make sure your knee comes out straight)
- Full weight-bearing, wean off crutches
- Quads and hamstrings co-contractions
- Straight leg raises
- Ankle range of motion (ROM) exercises
If unsure about the exercise program after leaving hospital, a physiotherapist appointment will be required..
Week 2 – 6:
The first postoperative appointment with Dr Biggs is needed 7 – 14 days following surgery. A postoperative knee X-Ray is required prior to to this review appointment.
- Full weight-bearing – no limp – gait training
- Ice before and after exercise till swelling has dissipated.
- Isometric quad exercise
- Isokinetic closed chain exercises.
- Step work, leg press, squats
- Active knee flexion and extension
- Stationary bike
- Swimming – no restriction
- 21 days commence proprioception
Weeks 6 - 12:
The ends of the new graft will heal into the newly created bony tunnels over 6-12 weeks.
It is believed that the graft is at its weakest at 8 weeks post surgery, so care must be taken at this stage despite the fact that the knee will feel quite good.
During this period the strength of the new graft actually decreases. This is due to the new blood supply into the graft removing some of the main structural fibres from it.
An appointment with Dr Biggs should be made at 6 weeks post surgery, with an X-Ray of your knee.
An early return to exercise and sport is possible once the wounds have healed and the swelling in the knee has settled. The graft is strong enough to allow unlimited movement of the knee and immediate full weight bearing
- Progressive training
- Step work, leg press, squats
- Sport specific drills
Return to sport when you have regained 90% strength and motion of the knee.
After Week 12
Following this period the graft will gradually increase in strength as new structural fibres are laid down. The results of ACL Reconstruction surgery are good in ~ 95% of cases.
Recovery from knee surgery can be a slow process
- By 6 months the knee is usually strong enough to resume all sports.
- By 12-18 months recovery is normally fully completed.
- There is no restriction to range of motion
- No bracing required