TOTAL KNEE ARTHROPLASTY

Total knee arthroplasty (TKA) also known as total knee replacement is a widely performed procedure for advanced arthritis of knee primarily in older patients (>70 years of age) with OA. The primary goal for TKA are to relieve pain and improve a patients  physical  function and Quality of life.

Indications:
•    Severe joint pain with weight bearing or motion that compromises functional abilities
•    Extensive destruction of articulating cartilage of knee
•    Marked deformity such as genu varum or valgum 
•    Failure of conservative management including canes , NSAIDS & lifestyle.

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Contraindications:
•    Severe osteoporosis
•    Systemic infections
•    Poor health
•    Non functioning extensor mechanism
•    Neuropathic arthopathy
•    Significant peripheral vascular diseases

IMPAIRMENTS

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BODY STRUCTURES

1. Sutures : anterior aspect of knee (vertical incision)

2. Resection of tibial and femoral condyles

3. Patellar resurfacing

4. Extensor mechanism disruption​

5. ​​​Relative structural impairments:

   • Tightness of hamstrings, iliopsoas, adductors

   • Atrophy of quadriceps (mainly VMO)

   • Contractures (fixed flexion deformity or extensor lag)

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BODY FUNCTIONS

1. Pain

2. Tenderness

3. Swelling

4. Restricted Rom

5. Muscle weakness

6. Joint play reduction

7. Reduced patellar mobility

8. Antalgic gait

9. Reduced phases of gait

GOALS

 

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• Short Term:

1. Patient and family education

2. Reduce pain

3. Prevent secondary complications

4. Improve RoM

5. Improve muscle strength

6. Improve wound healing

7. Improve soft tissue and joint integrity

8. Prevention of contractures

9. Achieve functional activities

 

• Long Term

1. Maintain range of motion

2. Maintain muscle strength

3. Maintain soft tissue and joint

4. Gait training

5. Prevent deformity

6. Ergonomic advice

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MANAGEMENT

It is divided into 3 phases:
Maximum protection phase
Moderate protection phase
Minimum protection phase

 

Exercise precautions following TKA  

• Postpone straight-leg raises (SLRs) in side-lying positions for 2 weeks after cemented arthroplasty and for 4 to 6 weeks after cementless/hybrid arthroplasty to avoid varus and valgus stresses to the operated knee.  

• Monitor the integrity of the surgical incision during knee flexion exercises. Watch for signs of excessive tension on the wound, such as drainage or skin blanching.

• Check with the surgeon to determine when it is permissible to initiate exercises against low-intensity resistance. It may be as early as 2 weeks or as late as 3 months postoperatively.

• Tibiofemoral joint mobilization techniques to increase knee flexion or extension may or may not be appropriate, depending on the design of the prosthetic components. It is advisable to discuss the use of these techniques with the surgeon before initiating them.

MAXIMUM PROTECTION: 1-4 weeks

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• Initiate isometric exercises: Straight Leg Raise, Quadriceps, Hamstrings

• Ambulate twice/day with knee immobilizer , assistance, and walker

• Cemented prosthesis: Weight Bearing As Tolerated(WBAT) with walker

• Non cemented: Touch down weight bearing (TDWB) with walker

• Transfer out of bed and into chair twice/day with knee in full extension

• CPM machine: not more than 40 degree of flexion

• Initiate Active ROM(AROM) and Active-Assisted ROM(A-AROM)

• Continue isometric exercises

• Begin PROM exercises for knee: knee extension, knee flexion, heel slides, wall slides

• Patellar mobilizations

• Active hip abduction and adduction exercises

• Continue these exercises for 6 weeks after surgery.

Exercises: 

Prevent vascular and pulmonary complications

• Ankle pumping exercises

• Deep breathing exercises

 

Prevent reflex inhibition or loss of strength of knee and hip musculature

• Muscle-setting exercises(Quadriceps, Hamstrings, Hip extensors and abductors)

  • Preferably coupled with Neuromuscular electrical stimulation(NMES)

• A-AROM progressing to AROM of the knee while seated and standing for gravity-resisted knee extension and flexion, respectively.

• As weight bearing on the operated lower extremity permits,

  • Wall slides

  • Mini-squats

  • Partial lunges

 

MODERATE PROTECTION PHASE : 4-8 weeks

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• Continue previous exercises

• Continue use of walker

• Ensure home PT and/or nursing care

• Do not permit driving for 4-6 weeks. patient must have regained functional ROM, good quad control.

• Orient  family to patients  needs, abilities, and limitations.

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EXERCISES

Increase strength and muscular endurance of knee and hip musculature

• Multiple-angle isometrics

• Low- intensity dynamic resistance exercises(Quadriceps, Hamstrings)

  • Light grade of elastic resistance or a cuff weight around the ankle

  • Perform in a variety of positions

  • Resisted Straight Leg Raise

• As weight bearing allows

  • Wall slides

  • Mini-squats

  • Partial lunges

  • Sit to stand tasks

Continue to increase knee ROM

• Low-intensity self-stretching

  • Prolonged stretch

  • Hold–relax technique

Improve standing balance

• Proprioceptive and balance training

  • Progress from bilateral to unilateral stance on stable surface

  • Balance activities on an unstable surface.

• Functional reaching activities while standing, stooping

• Knee flexion and extension.

MINIMUM PROTECTION PHASE: beyond 8 weeks

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• Begin weight bearing as tolerated with ambulatory aid

• Perform wall slides; progress to lunges

• Perform quad dips or step-ups

• Begin close chain exercises bilateral lower extremities, single leg exercises,incline.

• Progress to stationary bicycling.

• Kinesio-Taping

• Continue home physical therapy exercises
   

EXERCISES
From the 8th to 12th week

• Task- specific strengthening exercises

• Proprioceptive training

• Cardiopulmonary conditioning

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REFERENCES

Clinical Orthopaedic Rehabilitation by S. Brent Brotzman and Kelvin E. Wilk 2nd Ed.

Therapeutic Exercises by Carolyn Kisner and Lynn Allen Colby 7th Edition