The effect of a bracelet on gastrointestinal recovery after unicompartmental knee arthroplasty

ISRCTN	ISRCTN70004676
DOI	https://doi.org/10.1186/ISRCTN70004676
Heluo Young People Supporting Talents Project number	2024HLTJ17
Post-doctoral research funding project in Henan Province number	365154
Project of Science and Technology of Henan Province number	252102310082
Protocol serial number	2024ZXKT0009-01, 82104896
Special subject of scientific research of traditional Chinese medicine in Henan Province number	2024ZY3067
Start-up funds for doctoral research number	2024BS02
Sponsor	Luoyang Orthopedic-Traumatological Hospital of Henan Province
Funders	Post-doctoral research funding project in Henan Province, Heluo Young People Supporting Talents Project, Special subject of scientific research of traditional Chinese medicine in Henan Province, Start-up funds for doctoral research, Henan Provincial Science and Technology Research Project

Submission date: 06/11/2024
Registration date: 20/01/2025
Last edited: 09/10/2026

Recruitment status: Recruiting
Overall study status: Ongoing
Condition category: Surgery

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
With the increasing ageing population, the incidence of knee joint degeneration is increasing year by year. Unicompartmental knee arthroplasty (UKA) is surgery used to treat end-stage knee joint diseases, which can significantly relieve pain and correct deformity. Postoperative nausea and vomiting (PONV) and constipation are common complications of UKA. Therefore, reducing the incidence of nausea and vomiting is the focus of attention and research at present. Transcutaneous electrical acupoint stimulation (TEAS) via a wearable EmeTerm® bracelet at the Neiguan (PC6) acupoint is a non-invasive approach that can reduce the incidence of PONV, but it has not been studied in the setting of unicompartmental knee arthroplasty. This study therefore aims to evaluate the effect of the EmeTerm® bracelet on PONV and constipation after UKA.

Who can participate?
Patients aged 50 – 75 years with end-stage medial compartment knee osteoarthritis who are scheduled for primary unilateral unicompartmental knee arthroplasty

What does the study involve?
Participants are randomly assigned to receive active stimulation with the EmeTerm® bracelet or sham (device off) at identical time points. PONV is recorded within 24 hours after surgery (assessed at 6, 12, and 24 hours); constipation, bowel recovery, and adverse events are followed at 72 hours or discharge.

What are the possible benefits and risks of participating?
Possible risks of the surgery include deep venous thrombosis, knee joint stiffness, and acute knee infection. The benefits of participation include a better understanding of the effect of the bracelet on postoperative PONV after joint replacement.

Where is the study run from?
Luoyang Orthopedic Hospital of Henan Province, Orthopedic Hospital of Henan Province (China)

When is the study starting and how long is it expected to run for?
January 2025 to December 2027

Who is funding the study?
1. Post-doctoral research funding project in Henan Province
2. Heluo Young People Supporting Talents Project
3. Special subject of scientific research of traditional Chinese medicine in Henan Province
4. Start-up funds for doctoral research
5. Project of Science and Technology of Henan Province

Who is the main contact?
Guorui Cao, 13688172272@163.com

Contact information

Dr Guorui Cao
Public, Scientific, Principal investigator

82 Qiming South Road
Luoyang
471000
China

Phone	+86 (0)13258289917
Email	13688172272@163.com

Study information

Primary study design	Interventional
Study design	Parallel randomized controlled trial
Secondary study design	Randomised controlled trial
Scientific title	Effects of a wearable transcutaneous electrical acupoint stimulation bracelet on gastrointestinal reactions following unicompartmental knee arthroplasty
Study objectives	This study aims to evaluate the effect of the EmeTerm® bracelet in preventing nausea, vomiting and constipation in patients undergoing unicompartmental knee arthroplasty
Ethics approval(s)	Approved 01/01/2025, Luoyang Orthopedic Hospital of Henan Province Ethics Committee (82 Qiming South Road, Luoyang, 471000, China; +86 (0)13258289917; hnlc.love@163.com), ref: 2024ZXKT0009-01
Health condition(s) or problem(s) studied	Postoperative nausea, vomiting and constipation in patients undergoing knee replacement
Intervention	Current interventions as of 09/10/2026: Using an acupoint stimulation bracelet (EmeTerm®), a wearable transcutaneous electrical acupoint stimulation (TEAS) device, worn on the Neiguan (PC6) acupoint. Stimulation is delivered for 30 minutes per session at 30 minutes before anesthesia, immediately after surgery, and every 3 hours until 24 hours after surgery. The control group wears the same bracelet at identical time points with the device switched off (sham stimulation). Previous interventions: Using an acupoint stimulation bracelet (EmeTerm®) All patients received the same perioperative management and drug treatment. The incidence of PONV at different time points (3, 6, 12 and 24 hours after the operation) was measured, and the curative effect of SDZ-V on PONV after the operation was observed and analyzed.
Intervention type	Device
Phase	Not Applicable
Drug / device / biological / vaccine name(s)	Acupoint stimulation bracelet (EmeTerm®)
Primary outcome measure(s)	The incidence of postoperative nausea and vomiting (PONV) within 24 hours after surgery is measured using a standardized case-report form completed by blinded ward nurses and independent assessors at 6, 12, and 24 hours after surgery Previous primary outcome as of 09/10/2026: The incidence of PONV measured using questionnaire at 3, 6, 12 and 24 hours after the operation
Key secondary outcome measure(s)	Severity of nausea and vomiting measured using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 at 6, 12, and 24 hours after surgery The rate of postoperative nausea and vomiting (PONV) measured using a standardized case-report form at 6, 12, and 24 hours after surgery The rate of antiemetic rescue measured using a case-report form at 24 hours after surgery The postoperative first exhaust time measured using hours from the end of surgery by nurse-recorded assessment with telephone follow-up at 24 hours and at 72 hours (or at discharge if earlier) The postoperative first defecation time measured using hours from the end of surgery by nurse-recorded assessment with telephone follow-up at 24 hours and at 72 hours (or at discharge if earlier) The incidence of postoperative constipation, defined as no defecation within 72 hours or granular/lumpy faeces measured using the Bristol Stool Form Scale (types 1–2) at 72 hours after surgery (or at discharge if earlier) The rate of bracelet-related adverse events measured using a standardized adverse-event form at 6, 12, 24, and 72 hours (or at discharge) Patient satisfaction with gastrointestinal management measured using a 5-point Likert scale at 72 hours after surgery or at discharge Previous secondary outcomes as of 09/10/2026: 1. The severity of nausea and vomiting measured using questionnaire in the 24 hours after the operation 2. First exhaust time and defecation time after the operation, measured using questionnaire 3. Levels of hemoglobin, albumin and electrolyte in blood measured using hospital monitoring system after the operation 4. The incidence of constipation measured using questionnaire at 3 days after the operation 5. Stratified analysis on the basis of anesthesia method and the risk of nausea and vomiting
Completion date	31/12/2027

Eligibility

Participant type(s)	Patient
Age group	Mixed
Lower age limit	50 Years
Upper age limit	75 Years
Sex	All
Target sample size at registration	142
Key inclusion criteria	Current key inclusion criteria as of 09/10/2026: 1. Adults aged 50–75 years with end-stage medial compartment knee osteoarthritis; 2. Scheduled for primary unilateral unicompartmental knee arthroplasty; 3. American Society of Anesthesiologists (ASA) physical status I–III; 4. Able to understand and complete the study assessments; 5. Provision of written informed consent. Previous key inclusion criteria: 1. Patients aged 18 to 75 years who need knee replacement due to end-stage osteoarthritis 2. Patients who voluntarily participate in clinical trials and sign informed consent forms with good compliance
Key exclusion criteria	Current key exclusion criteria as of 09/10/2026: 1. Pacemaker, implantable glucose monitor, or cochlear implant; 2. Acupuncture treatment, or use of antiemetics or systemic steroids, within 2 weeks before surgery; 3. Severe hepatic or renal insufficiency; 4. Allergy to metal or study medications; 5. Existing nausea, vomiting, or constipation at screening; 6. Current use of drugs to treat nausea, vomiting, or constipation; 7. History of gastrointestinal surgery or severe gastrointestinal disease affecting bowel function; 8. Participation in another interventional trial. Previous key exclusion criteria: 1. Patients undergoing revision and bilateral joint replacement 2. Patients who have received acupuncture treatment within 2 weeks 3. Patients with rheumatoid disease, systemic lupus erythematosus and ankylosing spondylitis 4. Patients with severe deformity of knee joint (knee flexion ≥30 degrees, varus ≥30 degrees or valgus ≥15 degrees) 5. severe hepatic and renal insufficiency 6. Patients with central nervous system or mental illness 7. Those who are experiencing nausea, vomiting, diarrhea or constipation, and those who are taking drugs or non-drugs to treat nausea, vomiting, diarrhea or constipation, and those who are taking drugs that affect gastrointestinal motility 8. Skin allergy, breakage, infection or itching at the test site, etc
Date of first enrolment	10/01/2025
Date of final enrolment	31/12/2027

Locations

Countries of recruitment

China

Study participating centre

Luoyang Orthopedic Hospital of Henan Province

82 Qiming South Road
Luoyang
471000
China

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan	The datasets generated during the current study will be available upon request from Guorui Cao, 13688172272@163.com

Editorial Notes

09/10/2026: The following changes were made:
1. Scientific Title was changed from 'The effect of EmeTerm® bracelet on gastrointestinal reaction following unicompartmental knee arthroplasty' to 'Effects of a wearable transcutaneous electrical acupoint stimulation bracelet on gastrointestinal reactions following unicompartmental knee arthroplasty'.
2. Interventions, primary and secondary outcomes, key inclusion and exclusion criteria were updated.
3. Lower age was changed from 18 to 50 years.
4. Added the device name: acupoint stimulation bracelet (EmeTerm®).
5. Target sample size was changed from 360 to 142 participants (71 per group), allowing for a 15% attrition rate.
6. Funding by National Natural Science Foundation of China was replaced with the following:
6.1. Post-doctoral research funding project in Henan Province
6.2. Heluo Young People Supporting Talents Project
6.3. Special subject of scientific research of traditional Chinese medicine in Henan Province
6.4. Start-up funds for doctoral research
6.5. Project of Science and Technology of Henan Province
01/09/2026: The following changes were made to the study record:
1. The date of final enrolment was changed from 30/06/2025 to 31/12/2027.
2. The Completion date was changed from 31/12/2025 to 31/12/2027.
3. The target sample size at registration was changed from 240 to 360.
06/11/2024: Study's existence confirmed by the Luoyang Orthopedic Hospital of Henan Province Ethics Committee.