Medical Policy: 01.01.04
Original Effective Date: December 1993
Reviewed: August 2016
Revised: March 2016
Benefit determinations are based on the applicable contract language in effect at the time the
services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary
based on contract, and individual member benefits must be verified. Wellmark determines medical
necessity only if the benefit exists and no contract exclusions are applicable. This medical
policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document
was developed. Since that time, new technology may have emerged or new medical literature may
have been published. This Medical Policy will be reviewed regularly and be updated as scientific
and medical literature becomes available.
Continuous passive motion (CPM) devices are used to keep a joint in motion without patient assistance. CPM is being evaluated for treatment and postsurgical rehabilitation of the upper- and lower-limb joints and for a variety of musculoskeletal conditions.
The device moves the joint (e.g., flexion/extension), without patient assistance, continuously for extended periods of time (i.e., up to 24 hours/day). An electrical power unit is used to set the variable range of motion (ROM) and speed. The initial settings for ROM are based on a patient’s level of comfort and other factors that are assessed intraoperatively. The ROM is increased by 3 to 5 degrees per day, as tolerated. The speed and ROM can be varied, depending on joint stability. The use of the devices may be initiated in the immediate postoperative period and then continued at home for a variable period of time.
Physical therapy (PT) of joints following surgery focuses both on passive motion to restore mobility and active exercises to restore strength. While passive motion can be administered by a therapist, CPM devices have also been used. Continuous passive motion (CPM) is thought to improve recovery by stimulating the healing of articular tissues and circulation of synovial fluid; reducing local edema; and preventing adhesions, joint stiffness or contractures, or cartilage degeneration. CPM has been most thoroughly investigated in the knee, particularly after total knee arthroplasty (TKA) or ligamentous or cartilage repair, but its acceptance in the knee joint has created interest in extrapolating this experience to other weight-bearing joints (i.e., hip, ankle, metatarsals) and non-weight-bearing joints (i.e., shoulder, elbow, metacarpals, interphalangeal joints). Use of CPM in stroke and burn patients is also being explored.
Most research on CPM has been as a postoperative treatment for total knee arthroplasty (TKA). Numerous randomized controlled trials (RCTs) have been performed comparing CPM as an adjunct to physical therapy (PT) for patients undergoing TKA. Early trials generally used CPM in the inpatient setting and are less relevant to today’s practice patterns of short hospital stays followed by outpatient rehabilitation. Current postoperative rehabilitation protocols are considerably different than when the largest body of evidence was collected, making it difficult to apply the available evidence to the present situation.
Based on review of the evidence on total knee replacement that includes several RCTs and a large Cochrane review with a body of evidence extending back to the 1980’s. The systematic reviews identified described limited clinical usefulness for CPM in rehabilitation after knee surgery and described the quality of the evidence as low. The Cochrane review by Harvey et. al. 2014 included 24 RCTs with 1,445 patients and described the effects of CPM on outcomes after total knee replacement such as range of motion, function, pain and quality of life as “not clinically important.”
With respect to reducing deep-venous thrombosis after total knee replacement, the systemic review by He et. al. concluded the evidence is insufficient to determine a benefit from using CPM. This review included 11 RCTs with 808 patients. The results of the meta-analysis showed no evidence that CPM had any effect on preventing venous thrombosis after total knee replacement.
Continuous passive motion (CPM) is also commonly used postoperatively following articular cartilage repair surgery. Unfortunately, the clinical evidence to support the use of CPM is lacking (only 4 clinical studies) and despite the overwhelming abundance of basic science support and the common clinical practice of the use of CPM postoperatively the study results were heterogeneous and were considered low-quality evidence of any benefit from CPM when used after these procedures. Further randomized controlled trials are needed comparing the use of CPM in patients undergoing the same cartilage restoration procedure with patients treated without CPM and only active ROM which would provide high-quality clinical outcome research on which to base postoperative decisions. Also, based on the literature changes in clinical practice have occurred over time which is allowing weight bearing as tolerated immediately following cartilage repair with a gradual increase to full weight bearing at 8 weeks which has been reported to safely improve pain, function, and activity compared to more conservative progression with no increase of complications as of 3 months post operation. Studies also support the need for some degree of compressive loading in addition to joint motion for successful cartilage healing.
The literature suggests that institutional and home use of CPM has minimal benefit alone or when combined with standard PT after TKA, TKA revision or intra-articular cartilage repair. For patients who are unable to participate in standard PT regimens (due to low postoperative mobility or inability to comply with rehabilitation exercises), CPM remains as an alternative PT modality.
For use of CPM in joints other than the knee, there is limited published evidence. In addition, clinical support was limited for these indications. Three small RCTs of CPM post‒rotator cuff surgery have been identified in the literature. There is some evidence that use of CPM following rotator cuff repair of the shoulder improves short-term pain and range of motion (ROM); however, this is not high quality evidence, and the small differences in outcomes may not be clinically important. Two of these trials report short-term improvements in ROM for patients undergoing CPM, and 1 reports a short-term reduction in pain. None of the trials report long-term improvements, nor are there any reported benefits in functional status or quality of life. Therefore, the clinical significance of the short-term improvements reported is uncertain. In addition, there is uncertainty about the optimal PT regimen post‒shoulder surgery such that the optimal comparison for CPM is not clear. Larger RCTs with longer follow-up are required to determine whether CPM following rotator cuff surgery results in clinically meaningful improvements in health outcomes. The available evidence is insufficient to permit conclusions concerning the effect of this technology on health outcomes for all other joints.
Summary
Based on review of the medical literature the literature reports an improvement in ROM for patients receiving CPM, but these improvements are short term, of small magnitude, and of uncertain clinical significance. No RCTs have reported clinically meaningful improvements in important clinical outcomes such as functional status and/or quality of life compared to those who used CPM in adjunct to physical therapy following TKA, TKA revision or articular cartilage repair surgery.
The literature suggests that institutional and home use of CPM has minimal benefit alone or when combined with standard PT after TKA, TKA revision or intra-articular cartilage repair. For patients who are unable to participate in standard PT regimens (due to low postoperative mobility or inability to comply with rehabilitation exercises), CPM remains as an alternative PT modality.
For use of CPM in joints other than the knee, there is limited published evidence. In addition, clinical support was limited for these indications. There may be some evidence that use of CPM may improve short term pain and range of motion, but these improvements are short term, of small magnitude, and of uncertain clinical significance. Larger RCTs with longer follow-up are required to determine whether the use of CPM in joints other than the knee shows clinically meaningful improvements in health outcomes. The available evidence is insufficient to permit conclusions concerning the effect of this technology on health outcomes for all other joints.
Practice Guidelines and Position Statements
American Academy of Orthopedic Surgeons (AAOS)
In 2015, the American Academy of Orthopedic Surgeons issued an evidence based clinical practice guideline for the surgical management of osteoarthritis of the knee which states: "Continuous Passive Motion: Strong evidence supports that CPM after knee arthroplasty (KA) does not improve outcomes. Strength of recommendations: Strong Evidence."
Regulatory Status
CPM devices are considered class I devices by the FDA and are exempt from 510(k) requirements. This classification does not require submission of clinical data regarding efficacy but only notification of the FDA before marketing.
Not applicable
Note: The administration of CPM devices of the knee in the home setting in lieu of or in conjunction with physical therapy will be administered beginning April 26, 2016.
If the CPM device is determined to be medically necessary, the CPM is payable only as rental equipment for 30 days following surgery.
Medically Necessary
Use of continuous passive motion (CPM) device in the home setting may be considered medically necessary in the below situations as an alternative to physical therapy when the patient has low postoperative mobility or inability to comply with rehabilitation exercises (this may include patients with complex regional pain syndrome (reflex sympathetic dystrophy); extensive arthrofibrosis or tendon fibrosis; or physical, mental, or behavioral inability to participate in active physical therapy):
The literature suggests that institutional and home use of CPM has minimal benefit alone or when combined with standard PT after TKA, TKA revision or intra-articular cartilage repair. For patients who are unable to participate in standard PT regimens (due to low postoperative mobility or inability to comply with rehabilitation exercises), CPM remains as an alternative PT modality
Not Medically Necessary
All other uses for the Continuous Passive Motion (CPM) device in the home setting are considered not medically necessary including but not limited to the following circumstances:
Based on review of the medical literature the literature reports an improvement in ROM for patients receiving CPM, but these improvements are short term, of small magnitude, and of uncertain clinical significance. No RCTs have reported clinically meaningful improvements in important clinical outcomes such as functional status and/or quality of life compared to those who didn’t use CPM or used CPM in adjunct to physical therapy. The available literature does not support their use postoperatively. Further randomized controlled trials are needed comparing the use of CPM in patients undergoing the same procedures with patients treated without CPM and only active ROM which would provide high-quality clinical outcome research on which to base postoperative decisions and therefore CPM is considered not medically necessary.
Duplicate rehabilitative therapy is considered not medically necessary. When individuals are receiving physical therapy the therapist should provide different treatments and not duplicate the same treatment (i.e. CPM provides ROM (range of motion) and physical therapy protocols also typically provide ROM treatment/services).
Wellmark medical policies address the complex issue
of technology assessment of new and emerging treatments, devices,
drugs, etc. They are developed to
assist in administering plan benefits and constitute neither offers of
coverage nor medical advice. Wellmark medical policies contain only a
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and, therefore, cannot guarantee any results or outcomes.
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advice and treatment of members. Our medical policies may be updated
and therefore are subject to change without notice.
*Current Procedural Terminology © 2012 American Medical Association. All Rights Reserved.