Continuous Passive Motion Continuous Passive Motion (CPM): refers to passive motion that is performed by a mechanical device that moves a joint slowly and continuously through a controlled range of motion.

Continuous Passive Motion Device for the Knee.

Benefits of Continuous Passive Motion Preventing development of adhesion, contracture and joint stiffness. Providing a stimulating effect on the healing of tendons and ligaments. Minimizing the effect of immobilization. Increasing the synovial fluid of the joint so increase rate of intra-articular healing.

Indications After joint surgery, including anterior cruciate ligament (ACL) After knee arthoroplasty After surgical repair of stable intra-articular or extra-articular fractures After meniscectomy After osteochondral repair

Contraindication Continuous passive motion is contraindicated in cases for which the device can cause unwanted translation of opposing bones, overstressing the healing process.

Precautions The use of CPM in conjunction with anticoagulation therapy may produce an intra-compartmental haematoma. Skin irritation from the straps or carriage cover may develop.

Clinical Application of Continuous Passive Motion General Principles: The CPM unit is often applied in the recovery room immediately after surgery even when the patient is wearing brace or surgical bandages. The arc of motion for the joint is determined. Often a low arc of 20 to 30 degrees is used initially and progressed to 10 to 15 degrees per day. The rate of motion is usually 1 cycle per 45 seconds or per 2 minutes. The amount of time on the CPM machine ranges from 1 hour, three time a day to continuous for 24 hours. After surgery use is for 6 to 8 hours a day. Physical therapy treatment is provided during the time the patient is not on the CPM machine. Duration minimum for CPM is usually less than one week when a satisfactory range of motion is reached.

The following protocol is provided as an example for a post-ACL reconstructive surgery. Setup and Application: Measure the length of the patient’s thigh from the ischial tuberosity to the joint line of the knee. Adjust the proximal carriage so that the proximal end meets the bottom of the buttocks. Determine the length of the lower leg by measuring from the joint line of the knee to approximately ¼ inch beyond the heel. Adjust the distal portion of the carriage accordingly. Place the lower extremity in the unit with the joint line of the knee aligned to the articular hinge of the CPM unit. Adjust the foot in the footplate so that the tibia is placed in the neutral position. Internal or external rotation of the tibia can result in increased stress on the ACL.

Set the Rom as prescribed by the surgeon Set the Rom as prescribed by the surgeon. Usually started with a limited ROM (0 to 60 degrees) and progress to the full ROM as healing occurs. Set the speed of the treatment (e.g., cycle time of 4 minutes; 15 cycles per hour). Give the patient the hand held control and provide instruction on how and when to use it, including increasing speed and ROM and termination of the treatment. After termination of the treatment remove the machine and clean the mechanical housings with soap specially if the unit become soiled with blood or synovial fluid. Dispose of the carriage cover or wash it according to the manufacture’s instructions.