CHAMGAP
Verdict No. 1890 · Search date 2026-07-24 · Methodology v1.0

Continuous passive motion,
does it really help with Clinically meaningful additional range-of-motion, pain, and functional recovery after total knee arthroplasty?

30-Second Summary
D
Evidence Grade D · 30 · Safety caution
Legacy grade under review
Additional recovery benefit over standard rehabilitation remains uncertain; this does not exclude every small benefit.
Device pressure, discomfort, skin irritation, worsened pain, falls, or tubing hazards can occur. Follow the surgical team's prescribed range and contraindications.
What the
research shows
Continuous passive motion earns D with 30 points because any benefit after total knee arthroplasty appears small and trial results conflict. Short-term active flexion in Cochrane was MD 2.40 degrees (95% CI -0.22 to 5.03), I-squared 43%, tau-squared 7.31, from 10 trials and 470 participants.
What the
ads claim
The fact that a machine repeatedly moves the knee should not be converted into faster functional recovery. A difference of a few joint-angle degrees did not translate into better walking or daily function.
*

Useful facts when choosing a product

  • The short-term active-flexion estimate was 2.40 degrees (95% CI -0.22 to 5.03) in 10 trials and 470 participants.
  • Lenssen day-17 passive flexion was 93.0 versus 89.7 degrees, and active flexion was 89.9 versus 86.7.
  • No validated between-group flexion threshold after total knee arthroplasty was established, and within-person standards cannot be transferred.
ID

Chamgap Semantic Classification Code

Candidate index · review held

P.continuous-passive-motion-device.device.clinically-meaningful-additional-range-of-motion-pain-and-functional-recovery-after-total-knee-arthroplasty.assess.active

Procedures, devices and tests > Continuous passive motion device > Device delivered > Clinically meaningful additional range-of-motion, pain, and functional recovery after total knee arthroplasty > Association or change assessment > Active comparator

An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.

Download semantic index (JSON) · Codebook v1

01

What the research actually shows

Cochrane short-term active flexion included 10 trials and 470 participants, MD 2.40 degrees (95% CI -0.22 to 5.03), I-squared 43%, tau-squared 7.31. Lenssen 2008 randomized 60 participants, 30 per group, using intention-to-treat analysis and blinded assessment. At day 17, passive flexion was 93.0 versus 89.7 degrees, difference 3.3 (95% CI -1.4 to 8.1), and active flexion was 89.9 versus 86.7, difference 3.2 (95% CI -1.4 to 7.8); its meta-analytic estimate was about 3.2 (-1.26 to 7.66). The 88.7-versus-84.0 values were total passive range of motion, not passive flexion, and the study assessed function and range at multiple times.

02

Why this is classified as D (30)

A small benefit remains possible, but trial results conflict and no validated between-group threshold exists, supporting D with 30 points rather than definitive futility.

Counterpoint. Unusual revision or severe-stiffness cases require individual judgment, but routine add-on use after uncomplicated primary arthroplasty is unsupported.

Rejudgment record. Cross-check applied — Distinguished uncertainty from definitive futility because trials were small and conflicting and no validated between-group flexion threshold exists after total knee arthroplasty

Stored scoring profile
EndpointPSymptom or function itself is the target - including patient reports and performance tests
ReplicationR0Trials conflict in direction
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE0Null
PrecisionC0The confidence interval leaves room for benefit

Stored derived and displayed grades match; this is not a current recalculation or validity check (D).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Clinically meaningful increase in knee flexionDA small benefit remains possible and no validated between-group threshold exists.
Reduced postoperative painDThe pooled direction was null but was not treated as definitive repeated refutation.
Improved medium-term function and quality of lifeDBenefit was unclear, but clinically important change was not treated as definitively excluded.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Lenssen TAF et al. 2008Assessor-blinded randomized active-control trial60 randomized and 60 analyzedFunding source not reported; conducted by university-hospital and university investigatorsFunction and range of motion assessed at multiple time pointsDay-17 passive flexion 93.0 versus 89.7 degrees, difference 3.3 (95% CI -1.4 to 8.1); active flexion 89.9 versus 86.7, difference 3.2 (-1.4 to 7.8)Small direct trial
Harvey LA et al. 2014Cochrane systematic review and meta-analysis of randomized trials24 trials and 1,445 participants; short-term active flexion in 10 trials and 470 participantsAcademic support from Australian NHMRC, the University of Sydney, and Cochrane; not a manufacturer-led reviewActive flexion, pain, function, and quality of lifeShort-term active flexion MD 2.40 degrees (95% CI -0.22 to 5.03), I-squared 43%, tau-squared 7.31; no validated between-group thresholdSynthesis of conflicting results
§

Receipt — 2 References

Retained evidence-access date: 2026-07-24. This correction checked record consistency; it did not reverify every original source or recertify the grade.

Lenssen TAF, van Steyn MJA, Crijns YHF, et al. Effectiveness of prolonged use of continuous passive motion (CPM), as an adjunct to physiotherapy, after total knee arthroplasty. BMC Musculoskelet Disord. 2008;9:60. PMID: 18442423. PMCID: PMC2386789. DOI: 10.1186/1471-2474-9-60.
Retained record · not newly source-verified
Harvey LA, Brosseau L, Herbert RD. Continuous passive motion following total knee arthroplasty in people with arthritis. Cochrane Database Syst Rev. 2014;2014(2):CD004260. PMID: 24500904. PMCID: PMC10646823. DOI: 10.1002/14651858.CD004260.pub3.
Retained record · not newly source-verified
Codex compared retained study and verdict records with ChatGPT's methodological consistency review. No new literature search, full-text acquisition, or external expert review was performed.
This correction by: Codex · Evidence date: 2026-07-24 · Corrections: 1

Correction log — 1

Corrections applied to this verdict, in chronological order. Changes are logged, not erased.

  • 2026-09-14 · Editorial correction and legacy-grade review notice — Qualified the summary that had asserted exclusion of clinically meaningful benefit. Grade and score are retained, not certified as a new final assessment. (grade D unchanged)

Cite the review status too

Legacy grade under review. New grade-card distribution is on hold.

[Chamgap] Continuous passive motion x recovery after total knee arthroplasty — legacy D · 30, under review. https://chamgap.com/en/verdicts/joint-bone/continuous-passive-motion-knee-arthroplasty-recovery/ · CC BY 4.0
!

What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.