Total knee arthroplasty (TKA), also known as total knee replacement, involves replacing the knee joint with prosthetic components. It is commonly performed in older patients with severe knee osteoarthritis to relieve pain and improve physical function. The knee joint is made up of the femur, tibia, and patella bones. During TKA, the ends of the femur and tibia are reshaped and metal and plastic implants are attached. Rehabilitation after TKA follows three phases - maximum, moderate, and minimum protection - focusing on restoring range of motion, strengthening muscles, and retraining walking. The goals of TKA are to reduce pain and improve quality of life.

1. TOTAL KNEE
ARTHROPLASTY

2. Anatomy of knee joint
 Made up of three bones:
 Femur (thigh bone)
 Tibia (lower leg bone)
 Patella (kneecap)

3. Anatomy of knee joint

4. Introduction
 Total knee arthroplasty is (TKA) is also called
as total knee replacement (TKR).
 It is an advance procedure done in older
patient having age >70 yrs.
 Patients with knee osteoarthritis under go for
TKR.
 The main goals for TKR are to relieve pain
and improve a patient’s physical function and
quality of life.

6. Indication for surgery
 Severe joint pain with weight bearing or
activity which causes pain.
 Extensive destruction of articular cartilage.
 Marked deformity of knee such as genu
varum/valgum.
 Gross instability or limitation of motion.
 Failure of non-operative management or
previous surgical procedure.

9. Contraindication
 Poor general health
 Severe osteoporosis
 Recurrent or current joint sepsis
 Neuropathic arthropathies
 Quadriceps insufficiency
 Flexion deformity of more than 60 degree
combined with varus & valgum
 Hyperextension more than 20-30 degree

10. Classification of knee implants
Uni-compartmental
Bi-Compartmental
Tri-Compartmental
1. unconstrained
2. semiconstrained
3.fully constrained

11. Unicompartmental implants
 These are used to replace the opposing articular
surfaces of the femur & tibia of either the medial or
lateral compartment of knee.
 The opposite compartment & the patello femoral
compartment remain into it.
 This implant are all of unconstrained type.

12. Bi-compartmental implants.
 These are used to replace the opposing articular
surfaces of the femur & tibia of both the medial or
lateral compartment of knee.
 resurfacing the patello femoral joint.
 This deficit & mechanical loosening of the implant
have resulted in rejection of this approach.

13. Tri-compartmental implant
 These implant not only replace the opposing surfaces of
the femur & tibia both of the medial & lateral
compartment but also provide for resurfacing the patello-
femoral articulation.
 Implants can be divided conveniently into 3 groups
according to the degree of mechanical constraint
provided.

14. 1.Unconstrained prosthesis
 They are primary resurfacing implants.
 Few implants in this category may provide
minimal restrain to rotation or translation.
 Prosthesis greatly depends on the integrity
of the soft tissue to provide jt stability.
 Soft tissue balancing is necessary to
achieve it stability while restoring proper
limb alignment.
Eg:- Toconley & PCA

15. 2.Semiconstrained prosthesis
 Largest no of prosthesis fall in this category.
 The degree of constrain possed by a given prosthetic
design varies from almost minimal to an extent only
somewhat less than in a fully constrained design.
 Combination of soft tissue release a proper prosthetic
selection may achieve a stable joint, muscle limb
alignment & correction of deformities like flexion
contracture of upto 45 degree & angular deformities of
20-25 degrees.
 Angular deformities associated with ligamentous laxity
are more easily corrected than fixed angular
deformities.

16. 3. Fully constrained prosthesis
 They permit flexion & extension in sggital
plane, but prevent adducting & abducting in
the coronal plane.
 They are
1. hinged constrained implants
-true hinges
-rotating hinges

17. Procedure
 An incision is made
over the front of the
knee and tibia.
 Femoral condyles
are exposed.
 Bone cuts are made
to fit the femoral
component.

18. Femoral IM Canal
 A reamer is passed through a hole near the
center of joint surface of lower end of femur
and into femur shaft

19. Cutting the Distal Femur
 Another resection
guide is anchored to
end of femur
 Pieces of femur are
cut off the front and
back
 As directed by the
miter slots in guide
 Then cuts are made
to bevel the end of
femur to fit implant

20. Cutting the Distal Femur (cont’d)

21. Cutting the Tibial Bone
 A resection guide is
attached to front of
tibia
 Direction of the
saw cuts in 3D
 AP tilt
 LM tilt
 Upper end of tibia
is resected

22. Placing the Femoral
Component
 Metal
component is
held in place by
friction
 In the
cemented
variety
 An epoxy
cement is
used.

23. Cutting the Tibial Bone
(cont’d)

24. Placing the Tibial Component
 Metal tray that
will hold plastic
spacer is
attached to the
top of the tibia

25. Placing the Plastic spacer
 Attached to the metal tray of tibial component

26. Preparing the Patella
 The
undersurface of
the patella is
removed.

27. Placing the Patella
Component
 The patella button is
usually cemented
into place behind
the patella

28. Completed Knee
Replacement

29. X-Ray of Completed Knee

30. Immobilization
 Knee is immobilized in bulky compression
dressing for a day or 2 post operatively.
 After the bulky dressing is removed a post knee
splint is often worn but is removed for daily
exercises.
 Cementless arthroplasty may require a longer
period of immobilization than a cemented
procedure to allow ingrowth of bone into the
prosthesis.
 A post knee splint may be indicated for use at
night for as long as 12 weeks post operatively.

31. Complications
 Intercondylar fracture
 Damage to peripheral nerve (eg. Peroneal nerve)
 Infection
 Joint instability subluxation
 Component loosening
 Risk of wound healing
 DVT
 Deep periprosthetic infection
 Patellar instability or tracking
 Limited knee flexion
 Impaired function of the extensor
mechanism(extensor lag)

32. Physiotherapy management
 Pre operative physiotherapy
1) breathing exercises.
2) strengthening exercises.
-teach isometric ex for hamstring, glutei &
quadriceps.
-Resistive ex for ankle & foot on the affected
side are taught.
3) ankle-pump exercises.
4)mobilization exercises.

33. Post operative
 The rehabilitation protocol for a patient with
TKR is dependent on following 3 phases.
1) Maximum protection phase.
2) Moderate protection phase.
3) Minimum protection phase.

34. Maximum protection phase
 To prevent pulmonary complication
-deep breathing & coughing exercises
-localized and generalized expansion ex to
maintain healthy respiratory system
-if there are secretions in the lungs as aresult
of G.A postural drainage is given.
 To prevent vascular complications
-ATM

35.  To promote health and reduce post operative
odema & pain.
-strong ankle pumping ex begins immediately
after surgery.
-elevation of foot end to assist venous return to
reduce swelling.
-to relieve pain, TENS may be given at site of
pain.

36.  To improve strength of quadriceps
-immediately after sx or as soon as patient can
tolerate, SQE are taught to the patient is
encouraged to practice them frequently in a
day.
-last 15 degree extension can be given
keeping pillow under the knee for quads lag.
-supported SLR is taught as early as possible.
-active knee extension in high sitting should be
started and gradually increase repetation,
which should be started on 5th day after
operation.

37.  To maintain the strength of hip muscles
-static & isometric ex for hip muscles and
hamstring muscles.
 To improve joint mobility for knee
-cpm is given
-active and active assisted ex for knee
-hold and relax should be started(70 degree
5-12 days)
-knee range must not exceed 40 in first 3 P.O
days as a transcutaneous oxygen tension of the
skin near the incision decreases., if it knee flexion
is >40 it may delay wound healing.

38.  To give proper gait training
-the extent to weight bearing is available
dependent upon the type of prosthesis
implanted.
-full weight bearing (12 weeks) & ambulation
without assistive device may not be
permissible for upto 12 weeks P.O
-with cement fixation weight bearing as
tolerated is permissible immediately after
surgery & increased to full weight bearing over
6 weeks.

39. yet patient should continue to use a cane
through
moderate & minimum protection phase of
rehabilitation until adequate strength & stability
are achieved.
isometric ex, rythmical stabilization & weight
transference may be practiced in stand but the
splint as retained for walking until 70-90 of flexion
is achieved.
gait training is commenced initially in parallel
bars & in front of mirror, so that the patient can
see & feel the correct pattern of walking.
gait training can then be progressed with a
walker or crutches.

40.  Managing uneven ground & slopes
 managing stairs
-within 5-12 days stairs case ascend and
descend maximum to be taught
-ability to climb stairs with alternate steps may
not be possible for some weeks.

41.  To make patient functionally independent
-patient is advised not to flex the knee more
than 90 degree. Hence, sitting on floor & cross
leg sitting is avoided.
-patient is advised to use western toilets & can
be made use the toilet as early as he can walk
with an aid.

42. Moderate protection phase
 To improve muscular strength
-as healing progresses, multiple angle
isometric resistance ex for quads and hams
can be added.
-adequate strength of knee extensor is most
important for stability of knee during wt.
bearing activities.
-resisted SLR in various position should be
included to increase the strength of hip
muscles.
-as weight bearing permits closed chain, mini
squats, lunges can be added to improve
stability.

43.  To increase ROM
-by 3-6 weeks knee flexion ex can be given
depending upon type of implant used
-gentle self stretching or contract relax ex are
also added
-stationary bicycle can be used.
-the cycle first may have the sit position as
high as possible to increase knee flexion, and
the seat can be gradually lowered.

44.  To give gait training
-single crutch walking & well assisted stair
activities is encouraged.
-Gait training with which emphasis on feet
knee swinging can be started with a cane and
in progression to full weight bearing by 6
weeks if cemented is done.
-yet patient should continue using single cane
til 12 weeks.

45. Minimum protection phase
 By 12th week after surgery, emphasis on
rehabilitation is done on muscle conditioning
so that the patient will have the strength 7
endurance to return to a full level of functional
activities.
-ambulation, stair climbing, & so on are
gradually increased.

46. Expected results
 Almost all patient report a significant relief of
pain with knee motion and weight bearing.
 Improvement in ROM may continue upto 12-24
months P.O but only minimal changes occur
compared to pre-op status.
 It may take 3 months p.o for a patient to regain
strength in quads & hamstring muscles.