1. Continuous Passive Motion (CPM)
Chapter 15

2. Purposes Produce passive joint motion Effects: Enhance nutrition
Increase metabolic activity
Stimulate tissue remodeling and regrowth of healing tissues:
Articular cartilage
Tendons
Ligaments

3. Types of CPM devices
Free Linkage
Anatomic
Nonanatomic

4. Free Linkage
Moves the limb through ROM by grasping it proximal and distal to the joint
Adjustable to patient
Contraindicated for unstable joints

5. Anatomic Design
Mimics natural motion of involved joint and the proximal joints
Most suitable for knees

6. Nonanatomical Design
Does not attempt to replicate natural joint motion
Compensatory movement occurs between limb and CPM unit

7. Physiological Effects of CPM
Encourages the remodeling of collagen along the lines of force
Reduces:
The negative effects of joint immobilization
Functional shortening
Cross linking of collagen
Capsular adhesions
Enhances the tensile strength of
Tendons
Allografts
Skin
Stimulate repair of articular cartilage

8. Physiological Effects
Fluid pressures
Extension:
Most joint volume
Low pressure
Flexion:
Least joint volume
High pressure
Changes in pressure creates a pumping effect
Circulates synovial fluid
Assists in the removal of:
Hemarthrosis
Periarticular edema
Blood from tissues surrounding joint

9. Range of Motion Total end range time (TERT)
Delivers a low load, prolonged stress
Increases ROM as TERT increases
Helps patient overcome the apprehension of moving joint after surgery
Decreases rate of atrophy
Limits functional shortening of muscle
No increase on cardiovascular system

10. Joint Nutrition Stimulates circulation of synovial fluids
Increases nutrient uptake
Meniscus
Articular cartilage

11. Edema Reduction Not clearly understood Varies according to:
The body part
Condition being treated
The passive movement of the limb and the elevation of the body part could assist in venous and lymphatic return by milking the muscle

12. Pain Reduction
Movement of joint activates the gate control pain theory
Other effects such as decreased edema could also decrease pain
Not used as an acute pain-control technique

13. Ligament Healing
ACL does not receive the same nutritional benefits from CPM as cartilage because of its separate synovial lining
Effective in allograft-augmented medial collateral ligament reconstruction

14. Contraindications Unwanted joint motion and overstressing
Unstable fractures
Spastic paralyses
Uncontrolled infection
Deep Vein Thrombosis

15. Clinical Applications
A CPM technician will use the manufacturers protocol to administer treatment following surgery
Precaution:
CPM devices should not be used in the presence of flammable gases

16. Treatment Duration Long term bouts: patient continuously attached
1-hour 3 times per day
6 to 8 hours a day post-surgery
In home treatments with home visits by physical therapist