Description
Patient-controlled stretching devices are used at home to increase range of motion (ROM) in patients who have impaired functional status due to decreased ROM. We address 2 types of commercially available devices. Static progressive stretch (SPS) devices (e.g., JAS, Static-Pro) provide low- to moderate-intensity stretching with a crank or ratchet that progressively increases the stretch within each session, and serial stretch devices (e.g., ERMI) that use hydraulics to alternate between periods of higher intensity stretch and relaxation.

For individuals who have functional limitations in ROM who receive SPS devices and physical therapy, the evidence includes randomized controlled trials (RCTs), a systematic review, and case series. Relevant outcomes include symptoms, change in disease status, functional outcomes, and quality of life. Three RCTs have evaluated SPS devices, but comparators in each differed (physical therapy, a dynamic splint, and a serial stretch device). One RCT reported significant improvements in Disabilities of the Arm Shoulder and Hand (DASH) questionnaire scores and shoulder ROM compared to physical therapy alone at the end of four weeks of treatment, with significant improvements maintained at the 2-year follow-up. A second RCT evaluating SPS in the elbow found comparable improvements in most ROM outcomes compared with dynamic splinting, with the exception of better DASH scores in the SPS group at six months and better flexion contracture in the dynamic splinting group at 12 months. A third RCT which compared SPS with serial stretch devices, found greater improvement in Western Ontario and McMaster University Osteoarthritis Index and knee flexion scores with the serial stretch devices. A systematic review and meta-analysis of case reports and series found that similar clinical efficacy for increasing elbow ROM and flexion can be achieved using dynamic splints, SPS devices, and static braces. It is not known whether patient compliance is higher with SPS devices, because results have indicated these devices improve ROM faster than comparators. The evidence is insufficient to determine the effects of the technology on health outcomes. 

For individuals who have functional limitations in ROM who receive serial stretch devices and physical therapy, the evidence includes 1 RCT and observational studies. Relevant outcomes include symptoms, change in disease status, functional outcomes, and quality of life. The best evidence consists of serial stretching with ERMI devices used to treat knee ROM. One small RCT and 1 larger retrospective comparative study have reported that high-intensity stretching with ERMI devices improved ROM more than lower intensity stretching devices in patients who were post injury or surgery. Other available data consist of retrospective case series that have demonstrated improved ROM in patients whose ROM had plateaued with physical therapy. The clinical significance of gains in this surrogate outcome measure is unclear. Further high-quality comparative trials are needed to determine whether these patient-controlled devices improve functional outcomes better than alternative treatments and identify the patient populations that might benefit. The evidence is insufficient to determine the effects of the technology on health outcomes.

Background
Range of Motion Impairments
Loss of full range of motion occurs in a significant proportion of patients following surgical procedures around a joint, such as total knee arthroplasty or anterior cruciate ligament reconstruction. The most common cause of severe postoperative motion loss is the development of intra-articular or extra-articular arthrofibrosis. Arthrofibrosis, characterized by periarticular fibrosis and bands of scar tissue, is described as a painful loss of end range of motion compared with the normal contralateral side. Loss of knee range of motion can lead to impairments in walking, sitting, rising range of motion a chair, and navigating stairs. In 2010, Stephenson et al. estimated that based on the annual rates of total knee arthroplasty and anterior cruciate ligament reconstruction, the number of major knee surgery patients affected by arthrofibrosis in the United States would be at least 85,000 per year, and approximately 21,000 patients each year would be at risk of requiring additional surgery.¹

Treatment
Treatment of arthrofibrosis may include physical therapy, manipulation under anesthesia, arthroscopic or open lysis of adhesions, or revision surgery. Conservative treatment typically consists of postoperative physical therapy with pressure stretching techniques and home exercises. When rehabilitation has failed, serial casting, static braces, or dynamic splints that provide low-load prolonged stretch may be used. Dynamic splints use spring loading or elastic bands to provide low-intensity tension (less than that exerted by a physical therapist) and are designed to be worn over relatively long periods (i.e., 6 – 8 hours or overnight). The efficacy of a stretching regimen to permanently remodel tissue is considered to be a function of the intensity, length of the session, number of sessions per day, and number of days per week that stretching is performed.²

This evidence review focuses on patient-controlled mechanical devices that provide either moderate- to high-intensity stretch or static progressive stretch in the home. Patient-controlled stretching devices are used at home to increase range of motion in patients who have impaired functional status due to decreased range of motion. We address 2 types of commercially available devices. Static progressive stretch devices (e.g., Joint Active Systems (JAS), Static-Pro) provide low- to moderate-intensity stretching with a crank or ratchet that progressively increases the stretch within each session, and serial stretch devices (e.g., End Range of Motion Improvement [ERMI]) use hydraulics to alternate between periods of higher intensity stretch and relaxation.

Improvement in functional outcomes, such as the ability to perform activities of daily living, is the primary goal of this intervention. Joint range of motion is an intermediate outcome. In 2000, one small study by Rowe et al. correlated knee range of motion with functional parameters and concluded that 110° is considered the functional range of motion necessary to allow patients to perform common activities of daily living such as navigating stairs, rising range of motion a low chair or commode, entering or exiting range of motion a car, or tying one’s shoes.³ This threshold of range of motion is therefore used as a measure of treatment success for individual patients. Loss of knee range of motion of more than 15°, which occurs in about 1% to 2% of patients after anterior cruciate ligament reconstruction, has been associated with loss of quadriceps muscle strength and the development of osteoarthritis.⁴ According to the knee examination form developed by the International Knee Documentation Committee (2000), an extension deficit of 6° to 10° or a flexion deficit of 16° to 25° when compared with the noninvolved knee is categorized “abnormal,” and an extension deficit of more than 10° or a flexion deficit of more than 25° when compared with the noninvolved knee is categorized “severely abnormal.”⁵ Range of motion thresholds in joints other than the knee have been less clearly defined.

Regulatory Status
The U.S. Food and Drug Administration (FDA) has determined that devices classified as “Exerciser, Non-Measuring” are considered Class I devices and exempt range of motion 510(k) requirements. This classification does not require submission of clinical data on efficacy, only notification to the FDA prior to marketing. FDA product code: ION. 

Policy
Dynamic splinting devices (dynamic (low-load prolonged stretch [LLPS]) devices are considered investigational and/or unproven and is therefore considered NOT MEDICALLY NECESSARY for use with joints other than knee, elbow, and wrist.

Dynamic splinting devices (dynamic (low-load prolonged stretch [LLPS]) devices are considered investigational and/or unproven and is therefore considered NOT MEDICALLY NECESSARY in the management of chronic joint stiffness or chronic fixed contractures including but not limited to joint trauma, fractures, burns, head and spinal cord injury, rheumatiod arthritis, plantar fasciitis, multiple sclerosis, musclar dystrophy, or cerebral palsy.

Bi-directional static progressive (SP) devices are considered investigational and/or unproven and is therefore considered NOT MEDICALLY NECESSARY for all indications.

Patient-actuated serial stretch (PASS) devices are considered investigational and/or unproven and is therefore considered NOT MEDICALLY NECESSARY for all indications. 

Patient-actuated end range motion stretching devices are considered investigational and/or unproven and is therefore considered NOT MEDICALLY NECESSARY.  

Policy Guidelines  
Please see the Codes table for details.

Rationale
Evidence reviews assess the clinical evidence to determine whether the use of technology improves the net health outcome. Broadly defined, health outcomes are the length of life, quality of life, and ability to function, including benefits and harms. Every clinical condition has specific outcomes that are important to patients and managing the course of that condition. Validated outcome measures are necessary to ascertain whether a condition improves or worsens; and whether the magnitude of that change is clinically significant. The net health outcome is a balance of benefits and harms.

To assess whether the evidence is sufficient to draw conclusions about the net health outcome of technology, 2 domains are examined: the relevance, and quality and credibility. To be relevant, studies must represent one or more intended clinical uses of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. For some conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence depend on study design and conduct, minimizing bias and confounding that can generate incorrect findings. The randomized controlled trial (RCT) is preferred to assess efficacy; however, in some circumstances, nonrandomized studies may be adequate. RCTs are rarely large enough or long enough to capture less common adverse events and long-term effects. Other types of studies can be used for these purposes and to assess generalizability to broader clinical populations and settings of clinical practice. The following is a summary of the key literature to date.

Static Progressive Stretch Devices
Clinical Context and Therapy Purpose
The purpose of static progressive stretch devices in patients who have functional limitations in range of motion is to provide a treatment option that is an alternative to or an improvement on existing therapies.

The question addressed in this evidence review is: Do static progressive stretch devices improve health outcomes compared to alternative treatments?

The following PICO was used to select literature to inform this review.

Patients
The relevant population of interest is patients with functional limitations in joint range of motion after injury or surgery.

Interventions
Static progressive stretch devices provide a low- to moderate-intensity force to hold a joint at its end range and gradually increase the stretch. In contrast to the long periods of low-intensity stretch provided by dynamic splinting devices, patient-controlled serial stretch and static progressive stretch devices are designed to be used for 15 to 30 minutes, in up to 8 sessions per day. Static progressive stretch devices are available for the knee, shoulder, ankle, wrist, and for pronation and supination. Patients are typically instructed to use them for 30 minutes, 3 times a day. During each session, patients adjust their device by turning a ratchet or turnbuckle to the maximum tolerated position of end-range stretch. Each position is held for several minutes to allow for tissue relaxation to occur, and the device is then advanced to a new position of stretch. It is proposed that the systems unload the joint to reduce joint surface pressures during the stretch. Devices that provide static progressive stretch include JAS^® (Joint Active Systems), Static-Pro^® (DeRoyal), Stat-A-Dyne^® (Ortho-Innovations), AliMed^® Turnbuckle Orthosis (AliMed), and Mayo Aircast^® (DJO).

Comparators
Conservative treatment typically consists of postoperative physical therapy with pressure stretching techniques and home exercises. When rehabilitation has failed, serial casting, static braces, or dynamic splints that provide low-load prolonged stretch may be used. Dynamic splints use spring loading or elastic bands to provide low-intensity tension (less than that exerted by a physical therapist) and are designed to be worn over relatively long periods (i.e., 6 – 8 hours or overnight).

Outcomes
Improvement in functional outcomes, such as the ability to perform activities of daily living, is the primary goal of this intervention. Joint range of motion is an intermediate outcome. According to the knee examination form developed by the International Knee Documentation Committee (2000), an extension deficit of 6° to 10° or a flexion deficit of 16° to 25° when compared with the noninvolved knee is categorized “abnormal,” and an extension deficit of more than 10° or a flexion deficit of more than 25° when compared with the noninvolved knee is categorized “severely abnormal.”⁵

For the elbow, normal range of motion is suggested to be 100° of flexion (range, 30° to 130°). The mean shoulder range of motion for activities of daily living has been described as 121° flexion, 46° extension, 128° of shoulder abduction, 116° of shoulder cross-body abduction, 90° of external rotation with abduction of 59°, and 102° of internal rotation with 0° of abduction. Functional range of motion for the wrist his considered to be 38° of wrist flexion, 40° of wrist extension. For the knee,110° of flexion is an appropriate goal for activities of daily living such as stair climbing and sitting in a chair. ⁶

Functional outcome measures include the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) for the hip and knee, and Disabilities of the Arm Shoulder and Hand questionnaire (DASH) for the upper limb. The DASH is a 30-item questionnaire on symptoms and functional activities (5 levels ranging range of motion no difficulty to unable to perform) which calculates a score ranging range of motion 0 (no disability) to 100 (most severe disability).

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

1. To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs. 
2. In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
3. To assess longer-term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
4. Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Three RCTs, 1 evaluating JAS devices in the knee, shoulder, and elbow, and a systematic review of case reports and case series were identified. Characteristics and outcomes for the 3 RCTs are reported in Table 1 and described in greater detail below.

Table 1. Summary Characteristics of RCTs Using Static Progressive Stretch Devices To Treat Restricted Range of Motion

End Range of Motion Improvement: EMRI; HIS: high-intensity stretch; LIS: low-intensity stretch; NR: not reported; PT: physical therapy; RCT: randomized controlled trial; ROM: range of motion; SPS: static progressive stretch; TKA: total knee arthroplasty. 

Knee
Randomized Controlled Trials
Papotto and Mills (2012) reported on a small (n = 20) RCT that compared high-intensity serial stretch with lower intensitystatic progressive stretch devices for home therapy in patients who had undergone total knee arthroplasty.⁷ High-intensity stretch was performed with the End Range of Motion Improvement (ERMI) Knee/Ankle Flexionater. Patients in this high-intensity stretch group were instructed to stretch at an intensity that mimicked the intensity provided by their physical therapists during outpatient sessions and to use the device in 20- to 30-minute sessions, for a total of 60 minutes per day. The lower intensity stretch group used an static progressive stretch device (Static-Pro Knee), which consists of a brace secured to the upper and lower leg with cuffs and straps. These patients were instructed to use the Static-Pro Knee in three 30-minute sessions each day, increasing the force applied to the joint every 5 minutes. After an average of 7 weeks of treatment, patients treated with ERMI reported significantly greater improvement in knee flexion, change in range of motion, and WOMAC scores compared with the static progressive stretch patients (see Table 2).

Table 2. Summary Results of RCTs Using static progressive stretch Devices To Treat Restricted Knee Range of Motion

HIS: high-intensity stretch; LIS: low-intensity stretch; RCT: randomized controlled trial; ROM: range of motion; SPS: static progressive stretch; WOMAC: Western Ontario and McMaster University Osteoarthritis Index.

Case Series
Several case series on JAS devices have been published by a group of investigators that include Bonutti (stockholder in Joint Active Systems), McGrath, Ulrich, and Mont.

Bonutti et al. (2008) reported on a series of 41 patients with refractory knee stiffness who used an static progressive stretch (JAS) device after failing physical therapy.¹² Patients in this study had a total range of motion of less than 90° or a flexion contracture that impaired quality of life. Twenty-five patients had previously undergone manipulation under anesthesia. After a mean of 9 weeks of use (range, 3 – 27 weeks), mean range of motion increased by 33° (range, 0° – 85°), with mean final extension of -6° and flexion of 108°. Outcomes were comparable to those reported with other nonoperative treatments; however, improvements occurred in shorter treatment times with the static progressive stretch device.

Shoulder
Randomized Controlled Trials
Ibrahim et al. (2012) published an evaluator-blinded RCT of 60 patients with shoulder adhesive capsulitis randomized to 4 weeks of treatment with an static progressive stretch (JAS) device plus physical therapy compared with physical therapy alone.⁸ Ibrahim et al. (2014) and Hussein et al. (2015) provided additional follow-up at 1 year and 2 years.^9,10 The trial was independently funded, with devices provided by Joint Active Systems. Patients were evaluated for range of motion, functional outcomes with the DASH questionnaire, and visual analog scale for pain. Improvements in range of motion were statistically greater with the static progressive stretch device than with physical therapy alone (see Table 3), but this did not translate into a difference in pain and function at 4 weeks or in pain at 2 years. As noted above, the mean shoulder range of motion for activities of daily living has been described as 128° of shoulder abduction and 90° of external rotation with abduction of 59°. Final DASH scores were 2.5 in the static progressive stretch group compared with 36.2 in the control group (p < 0.001). It is unclear why functional limitations would increase in the control group over 2 years when adhesive capsulitis is generally a self-limiting condition. Authors reported that there were no losses to follow-up over 2 years. A limitation of the study is that the comparator of physical therapy alone was not provided with the same duration as physical therapy plus static progressive stretch (Tables 4 and 5) Use of an active comparator such as dynamic splinting would provide greater certainty on the effectiveness of this technology.

Table 3 Summary Results of RCTs Using Static Progressive Stretch Devices To Treat Restricted Shoulder Range of Motion

CI: confidence interval; DASH: Disabilities of the Arm Shoulder and Hand questionnaire; PT: physical therapy; RCT: randomized controlled trial; range of motion: range of motion; SD: standard deviation; static progressive stretch: static progressive stretch; VAS: visual analog scale.

Table 4. Relevance Limitations

The study limitations stated in this table are those notable in the current review; this is not a comprehensive limitations assessment.
^a Population key: 1. Intended use population unclear; 2. Clinical context is unclear; 3. Study population is unclear; 4. Study population not representative of intended use.
^b Intervention key: 1. Not clearly defined; 2. Version used unclear; 3. Delivery not similar intensity as comparator; 4.Not the intervention of interest.
^c Comparator key: 1. Not clearly defined; 2. Not standard or optimal; 3. Delivery not similar intensity as intervention; 4. Not delivered effectively.
^d Outcomes key: 1. Key health outcomes not addressed; 2. Physiologic measures, not validated surrogates; 3. No CONSORT reporting of harms; 4. Not establish and validated measurements; 5. Clinical significant difference not prespecified; 6. Clinical significant difference not supported.
^e Follow-Up key: 1. Not sufficient duration for benefit; 2. Not sufficient duration for harms.

Table 5. Study Design and Conduct Limitations

ROM: range of motion
The study limitations stated in this table are those notable in the current review; this is not a comprehensive limitations assessment.
^a Allocation key: 1. Participants not randomly allocated; 2. Allocation not concealed; 3. Allocation concealment unclear; 4. Inadequate control for selection bias.
^b Blinding key: 1. Not blinded to treatment assignment; 2. Not blinded outcome assessment; 3. Outcome assessed by treating physician.
^c Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication.
^d Data Completeness key: 1. High loss to follow-up or missing data; 2. Inadequate handling of missing data; 3. High number of crossovers; 4. Inadequate handling of crossovers; 5. Inappropriate exclusions; 6. Not intent to treat analysis (per protocol for noninferiority trials).
^e Power key: 1. Power calculations not reported; 2. Power not calculated for primary outcome; 3. Power not based on clinically important difference.
^f Statistical key: 1. Analysis is not appropriate for outcome type: (a) continuous; (b) binary; (c) time to event; 2. Analysis is not appropriate for multiple observations per patient; 3. Confidence intervals and/or p values not reported; 4. Comparative treatment effects not calculated.

Elbow
Randomized Controlled Trials
Lindenhovius et al. (2012) reported on results range of motion an RCT that compared static progressive stretch using a JAS device with dynamic splinting in 66 patients with posttraumatic elbow stiffness.¹¹ Patients included had lost more than 30° in flexion or extension after an elbow injury or surgery and had failed to improve for at least 4 weeks with regular stretching exercises. The evaluation was conducted by an investigator not involved in the care of the patients but who did not appear to have been blinded. Ten percent of patients in the dynamic splinting cohort asked for a change in treatment due to discomfort with the splint. Follow-up at 12 months was available for 80% of patients in the static progressive stretch group and 68% of patients in the splinting group, potentially reflecting lower patient satisfaction with dynamic splinting. Improvements were comparable between the groups in most outcomes (flexion-extension arc, flexion, forearm rotation), with the exception of DASH scores (significantly better in the static progressive stretch group at 6 months but equivalent at 12 months) and flexion contracture (equivalent at 6 months but significantly better in the splinting group at 12 months), (see Table 6). Statistical analysis was intention-to-treat but did not account for repeated measures or baseline covariates. range of motion was similar between groups at all time points.

Table 6. Summary Results of RCTs Using Static Progressive Stretch Devices to Treat Restricted Range of Motion

DASH: Disabilities of the Arm Shoulder and Hand questionnaire; DS: dynamic splinting; RCT: randomized controlled trial; ROM: range of motion; SPS: static progressive stretch.

Non-Randomized Comparative Studies
In an unpublished study listed on clinicaltrials.gov, preliminary data showed no significant differences in functional outcomes between the static progressive stretch device and physical therapy 3 times a week, a Multi-Center Controlled Trial of Static Progressive Splinting Status Post Elbow Fractures and Dislocations (NCT00580866).

Case Series
Ulrich et al. (2010) reported on the use of an static progressive stretch (JAS) elbow device in 37 patients. Patients with deficits in flexion or extension had undergone at least 6 weeks of exercise with at least 2 weeks of minimal motion gain ( < 5°).¹³ After 1 to 3 daily, 30-minute sessions for a mean treatment time of 10 weeks (range, 2 – 23 weeks), mean range of motion increased by 26° (range, 2° – 60°) to a final range of motion of 107° (range, 70° – 140°). Results were compared with the literature on other upper-extremity stretch devices (e.g., splints), which achieved similar success rates (81% – 88%) with 6 to 10 hours of daily wear over 6 to 10 months.

Systematic Reviews
A systematic review by Muller et al. (2013) compared the effectiveness of dynamic splint, static splint, or static progressive stretch in patients with posttraumatic or postoperative elbow stiffness.¹⁴ They included 13 case series and case reports (total n = 247 patients; range, 1 – 37 patients). Mean time range of motion the incident to the start of treatment was 6.9 months. The greatest increase in range of motion was obtained with dynamic splints (46°), followed by static progressive stretch devices (40°) and static splints (34°). These differences were statistically significant (p < 0.001) but might not be clinically significant. None of the selected studies assessed patient compliance, which is potentially affected by the duration of wear and comfort of the device. This systematic review was limited by the inclusion of low-quality studies, including case reports.

Forearm Rotation
Case Series
McGrath et al. (2009) reported on a series of 38 consecutive patients with limitations in forearm rotation who had plateaued with physical therapy.¹⁵ Treatment with an static progressive stretch (JAS) pronation/supination device began at an average of 21 weeks (range, 6 – 75 weeks) after the upper-extremity injury. At the start of treatment, mean range of motion was 96° (range, 20° – 150°). After an average of 12 weeks of treatment (range, 3 – 57 weeks), mean range of motion increased to 138° (range, 70° – 180°).

Wrist
Case Series
McGrath et al. (2008) also reported on the use of an static progressive stretch (JAS) wrist device in 47 consecutive patients with posttraumatic or postsurgical wrist stiffness.¹⁶ All patients’ range of motion had plateaued (67°; range, 18° – 114°) after a mean of 12 weeks of physical therapy (range, 6 – 28 weeks) and was not expected to improve with standard therapeutic modalities. After a mean of 10 weeks of static progressive stretch treatment (range, 4 – 26 weeks), range of motion increased to 101° (range, 60° – 156°).

Lucado et al. (2008) retrospectively reviewed 25 patients with distal radius fractures who had been treated with a JAS Flexion/Extension device or JAS forearm Pronation/Supination device at their institutions.¹⁷ Mean time range of motion injury to the initiation of treatment with an static progressive stretch device was 94 days (range, 48 – 188 days), and duration of use was 75 days (range, 14 – 160 days). There were significant improvements in range of motion and DASH scores. Median DASH score improved range of motion 43 to 19 (/100) after static progressive stretch therapy.

Section Summary: Static Progressive Stretch Devices
Three RCTs have evaluated static progressive stretch devices but comparators in each differed (physical therapy, a dynamic splint, and serial stretch device). The evidence on static progressive stretch devices does not currently support an improvement in pain and function with static progressive stretch compared to alternative treatments such as dynamic splinting. One RCT found greater improvements in range of motion and WOMAC scores with serial stretch devices for the knee compared with static progressive stretch devices. Another RCT evaluating static progressive stretch for shoulder adhesive capsulitis found significant differences in shoulder range of motion compared with physical therapy alone at the end of 4 weeks of treatment, with no difference in pain and function at this time point. At longer follow-up, the physical therapy group showed a decline in function. Use of an active comparator would prove greater certainty on the effectiveness of this technology. A third RCT found comparable improvements in most outcomes for the static progressive stretch device compared with dynamic splinting, and a systematic review of case reports and series found similar clinical efficacy for increasing elbow range of motion between static progressive stretch devices and dynamic splints. Dynamic splints are used for 8 to 24 hrs per day while static progressive stretch devices require several 30-minute sessions. It is not known whether patient compliance would be higher with the static progressive stretch devices resulting in an improvement in clinical outcomes.

Serial Stretch Devices
Clinical Context and Therapy Purpose
The purpose of serial stretch devices in patients who have functional limitations in range of motion is to provide a treatment option that is an alternative to or an improvement on existing therapies.

The question addressed in this evidence review is: Do serial stretch devices improve health outcomes compared to alternative treatments?

The following PICO was used to select literature to inform this review.

Patients
The relevant population of interest is patients with functional limitations in joint range of motion after injury or surgery.

Interventions
Serial stretch devices (e.g., ERMI) use hydraulics to alternate between periods of higher intensity stretch and relaxation.

Comparators
Conservative treatment typically consists of postoperative physical therapy with pressure stretching techniques and home exercises. When rehabilitation has failed, serial casting, static braces, or dynamic splints that provide low-load prolonged stretch may be used. Dynamic splints use spring loading or elastic bands to provide low-intensity tension (less than that exerted by a physical therapist) and are designed to be worn over relatively long periods (i.e., 6 – 8 hours or overnight).

Outcomes
Improvement in functional outcomes, such as the ability to perform activities of daily living, is the primary goal of this intervention. Joint range of motion is an intermediate outcome. According to the knee examination form developed by the International Knee Documentation Committee (2000), an extension deficit of 6° to 10° or a flexion deficit of 16° to 25° when compared with the noninvolved knee is categorized “abnormal,” and an extension deficit of more than 10° or a flexion deficit of more than 25° when compared with the noninvolved knee is categorized “severely abnormal.”⁵ range of motion thresholds in joints other than the knee are noted above.

Functional outcome measures include the WOMAC for the hip and knee and DASH for the upper limb.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

1. To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs. 
2. In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
3. To assess longer-term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
4. Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Knee
Randomized Controlled Trials
The small RCT by Papotto and Mills (2012; described above) compared a serial stretch (ERMI Knee/Ankle Flexionater) device with an static progressive stretch (Static-Pro) device for home therapy in 20 patients who had undergone total knee arthroplasty.⁷ After an average of 7 weeks of therapy, treatment with the serial stretch device resulted in a 29.9° gain in motion compared with 17.0° with static progressive stretch (p < 0.001). Knee flexion of 110° or more was obtained in 91% of the serial stretch group compared with 22% of the static progressive stretch group (p < 0.001). Improvement on the 100-point WOMAC was significantly greater in the serial stretch group (25.6) than in the static progressive stretch group (12.4; p = 0.048) (see Table 1).

Nonrandomized Comparative Studies
Stephenson et al. (2010) reported on an industry-funded retrospective comparative study of high-intensity stretch devices, low-intensity stretch devices, and no devices, based on claims data for 60,359 patients who had a diagnosis of arthrofibrosis following knee injury or surgery.¹ There were 143 patients who used a high-intensity stretch device, 607 who used a low-intensity stretch device, and 59,609 who did not use any stretching device. To make the groups comparable in terms of severity, the lower intensity stretch and no device patients were required to have a diagnosis relating to osteoarthrosis, ankyloses, contracture/fracture, or stiffness in the lower leg. After controlling for baseline differences in the type of knee surgery and musculoskeletal disease, the high-intensity stretch group had significantly lower rates of rehospitalization than low-intensity stretch and no device patients. Significantly more patients with no device (47.4%) had a knee event within 6 months range of motion the index surgery compared with high-intensity (24.5%) or low-intensity (22.2%) stretch patients.

Uncontrolled Trials
A frequently cited study was reported by Branch et al. (2003; Branch was medical director at ERMI).¹⁸ Patients (n = 34) in this prospective series who did not have full knee range of motion after 6 weeks of physical therapy were prescribed a serial stretch (ERMI Knee/Ankle Flexionater) device. The 2 patients in the study who had range of motion greater than 115° at the start of therapy regained full range of motion. Of the 6 patients with range of motion between 90° and 115° at the start of therapy, 5 gained full range of motion; and of the 16 patients with range of motion between 60° and 90° at the start of therapy, 13 regained full range of motion. For the 10 patients who began mechanical therapy with range of motion between 0° and 60°, only 4 regained full range of motion but this group regained the most range of motion (mean, 79°) of the 4 groups. With functional range of motion defined as 115° or more, 31 (91%) of the 34 patients met this goal, and the improvement in range of motion for the entire group was highly significant. A retrospective review range of motion this group found that passive knee extension deficits that had plateaued with physical therapy decreased range of motion 10.5° to 2.0° with the ERMI Knee Extensionater.

Shoulder
Case Series
An industry-funded retrospective series (2011) with 36 patients was identified; it evaluated a serial stretch (ERMI Shoulder Flexionater) device.¹⁹ Patients with adhesive capsulitis who had failed 6 weeks of physical therapy (glenohumeral abduction and external rotation not equal to the opposite uninvolved limb) were treated with the serial stretch device in combination with continued physical therapy. Patients were instructed to perform 6 daily, 10-minute sessions of end-range stretching at home, using an intensity that was uncomfortable but not painful. Blinded evaluation at the end of treatment found that range of motion of the involved limb equaled that of the opposite limb. Scores on the American Shoulder and Elbow Society Standardized Shoulder Assessment Form showed significant improvement (p < 0.05), and patients with greater pain at baseline had the greatest improvement in American Shoulder and Elbow Society scores (gain of 50 points of 100 total).

Section Summary: Serial Stretch Devices
The evidence includes a small RCT and a larger retrospective comparative study that reported high-intensity stretching using serial stretch (ERMI) devices improved range of motion more than lower intensity stretching devices in patients who were post-injury or surgery. Other available data consist of retrospective case series demonstrating improvements in range of motion among patients whose range of motion had plateaued with physical therapy. The clinical significance of gains in this surrogate outcome measure is unclear.

Summary of Evidence
For individuals who have functional limitations in range of motion who receive static progressive stretch devices and physical therapy, the evidence includes randomized controlled trials (RCTs), a systematic review, and case series. Relevant outcomes include symptoms, change in disease status, functional outcomes, and quality of life. Three RCTs have evaluated static progressive stretch devices but comparators in each differed (physical therapy, a dynamic splint, and a serial stretch device). The evidence on static progressive stretch devices does not currently support an improvement in pain and function with static progressive stretch compared to alternative treatments. One RCT found greater improvements in range of motion and Western Ontario and McMaster University Osteoarthritis Index scores with serial stretch devices for the knee compared with static progressive stretch devices. Another RCT evaluating static progressive stretch for shoulder adhesive capsulitis found significant differences in shoulder range of motion compared with physical therapy alone at the end of 4 weeks of treatment, with no difference in pain and function. A third RCT found comparable improvements in most outcomes for the static progressive stretch device compared with dynamic splinting, and a systematic review of case reports and series found similar clinical efficacy for increasing elbow range of motion between static progressive stretch devices and dynamic splints. It is not known whether patient compliance is higher with static progressive stretch devices. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have functional limitations in range of motion who receive serial stretch devices and physical therapy, the evidence includes an RCT and observational studies. Relevant outcomes include symptoms, change in disease status, functional outcomes, and quality of life. The best evidence consists of serial stretching with ERMI devices used to treat knee range of motion. One small RCT and a larger retrospective comparative study have reported that high-intensity stretching with ERMI devices improved range of motion more than lower intensity stretching devices in patients who were post-injury or surgery. Other available data consist of retrospective case series that have demonstrated improved range of motion in patients whose range of motion had plateaued with physical therapy. The clinical significance of gains in this surrogate outcome measure is unclear. Further high-quality comparative trials are needed to determine whether these patient-controlled devices improve functional outcomes better than alternative treatments and identify the patient populations that might benefit. The evidence is insufficient to determine the effects of the technology on health outcomes. 

Practice Guidelines and Position Statements
No guidelines or statements were identified.

U.S. Preventive Services Task Force Recommendations
Not applicable

Ongoing and Unpublished Clinical Trials
Currently unpublished trials that might influence this review are listed in Table 7.

Table 7. Summary of Key Trials

NCT: national clinical trial.

References 

1. Stephenson JJ, Quimbo RA, Gu T. Knee-attributable medical costs and risk of re-surgery among patients utilizing non-surgical treatment options for knee arthrofibrosis in a managed care population. Curr Med Res Opin. May 2010;26(5):1109-1118. PMID 20225995
2. Jacobs CA, Sciascia AD. Factors that influence the efficacy of stretching programs for patients with hypomobility. Sports Health. Nov 2011;3(6):520-523. PMID 23016052
3. Rowe PJ, Myles CM, Walker C, et al. Knee joint kinematics in gait and other functional activities measured using flexible electrogoniometry: how much knee motion is sufficient for normal daily life? Gait Posture. Oct 2000;12(2):143-155. PMID 10998612
4. Shelbourne KD, Gray T. Minimum 10-year results after anterior cruciate ligament reconstruction: how the loss of normal knee motion compounds other factors related to the development of osteoarthritis after surgery. Am J Sports Med. Mar 2009;37(3):471-480. PMID 19059893
5. International Knee Documentation Committee (IKDC). IKDC: Knee Form. 2000; https://www.sportsmed.org/aossmimis/Staging/Research/IKDC_Forms.aspx. Accessed February 8, 2020.
6. Sodhi N, Yao B, Anis HK, et al. Patient satisfaction and outcomes of static progressive stretch bracing: a 10-year prospective analysis. Ann Transl Med. 2019 Feb;7(4). PMID 30963062
7. Papotto BA, Mills T. Treatment of severe flexion deficits following total knee arthroplasty: a randomized clinical trial. Orthop Nurs. Jan-Feb 2012;31(1):29-34. PMID 22278649
8. Ibrahim MI, Johnson AJ, Pivec R, et al. Treatment of adhesive capsulitis of the shoulder with a static progressive stretch device: a prospective, randomized study. J Long Term Eff Med Implants. Jan 2012;22(4):281-291. PMID 23662659
9. Ibrahim M, Donatelli R, Hellman M, et al. Efficacy of a static progressive stretch device as an adjunct to physical therapy in treating adhesive capsulitis of the shoulder: a prospective, randomised study. Physiotherapy. Sep 2014;100(3):228-234. PMID 24211154
10. Hussein AZ, Ibrahim MI, Hellman MA, et al. Static progressive stretch is effective in treating shoulder adhesive capsulitis: Prospective, randomized, controlled study with a two-year follow-up. Eur J Physiother. Jun 24 2015;17(3):138-147.
11. Lindenhovius AL, Doornberg JN, Brouwer KM, et al. A prospective randomized controlled trial of dynamic versus static progressive elbow splinting for posttraumatic elbow stiffness. J Bone Joint Surg Am. Apr 18 2012;94(8):694-700. PMID 22517385
12. Bonutti PM, McGrath MS, Ulrich SD, et al. Static progressive stretch for the treatment of knee stiffness. Knee. Aug 2008;15(4):272-276. PMID 18538574
13. Ulrich SD, Bonutti PM, Seyler TM, et al. Restoring range of motion via stress relaxation and static progressive stretch in posttraumatic elbow contractures. J Shoulder Elbow Surg. Mar 2010;19(2):196-201. PMID 19959379
14. Muller AM, Sadoghi P, Lucas R, et al. Effectiveness of bracing in the treatment of nonosseous restriction of elbow mobility: a systematic review and meta-analysis of 13 studies. J Shoulder Elbow Surg. Aug 2013;22(8):1146-1152. PMID 23796383
15. McGrath MS, Ulrich SD, Bonutti PM, et al. Static progressive splinting for restoration of rotational motion of the forearm. J Hand Ther. Jan-Mar 2009;22(1):3-8; quiz 9. PMID 18950990
16. McGrath MS, Ulrich SD, Bonutti PM, et al. Evaluation of static progressive stretch for the treatment of wrist stiffness. J Hand Surg Am. Nov 2008;33(9):1498-1504. PMID 18984330
17. Lucado AM, Li Z, Russell GB, et al. Changes in impairment and function after static progressive splinting for stiffness after distal radius fracture. J Hand Ther. Oct-Dec 2008;21(4):319-325. PMID 19006757
18. Branch TP, Karsch RE, Mills TJ, et al. Mechanical therapy for loss of knee flexion. Am J Orthop (Belle Mead NJ). Apr 2003;32(4):195-200. PMID 12723771
19. Dempsey AL, Mills T, Karsch RM, et al. Maximizing total end range time is safe and effective for the conservative treatment of frozen shoulder patients. Am J Phys Med Rehabil. Sep 2011;90(9):738-745. PMID 21430510

Coding Section    

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

History From 2015 Forward