Effect of Night-time and Full-time Splinting for Carpal Tunnel Syndrome (FINCROSS)

Effect of Night-time and Full-time Splinting for Carpal Tunnel Syndrome: a Multi-center, Three-period, Randomized Cross-over Superiority Trial (FINCROSS - Finnish Crossover Trial for Carpal Tunnel Syndrome)

Carpal tunnel syndrome is a common compression neuropathy of upper extremities. Its usual symptoms are pain, numbness and tingling of fingers, which tend to be worse at night. Splinting the wrist with an external orthosis is usually a first-line treatment provided to most people with mild to moderate disease. The FINCROSS trial (randomized cross-over trial) aims to assess the effect of night-time and full-time splinting in comparison with no-treatment. It also aims to identify possible subgroups of people who would benefit from splinting, as well as assess if positive response to splinting is associated with subsequent lower need of surgery. The trial will recruit 110 people with carpal tunnel syndrome in Finland. Each participant will undergo all three treatment periods in a randomised order: 1) splinting at night-time for six weeks, 2) splinting both day and night for six weeks; and 3) be assessed under a six weeks long control period of no-treatment. Each treatment period will be separated with a three-week washout period. Therefore, the whole treatment sequence for each participant lasts 24 weeks after randomization. The participant will be followed-up to 1 year after the randomisation. Additionally, the participants will get instructions for self-administered stretching exercises to perform throughout the study. All participants will be asked to avoid any intervention administered or supervised by medical personnel (such as structured supervised exercises, manual therapy, steroid injections, surgery, etc.).

Multicentre, three-treatment, three-period, randomised, crossover superiority trial (3 x 6 crossover design)

Splinting at night while sleeping for 6 weeks (period A), then no treatment for 6 weeks (period B), then splinting at day and night for 6 weeks (period C). Each treatment period will be separated by 3-week washout period.

Splinting at night while sleeping for 6 weeks (period A), then splinting at day and night for 6 weeks (period C), then no treatment for 6 weeks (period B). Each treatment period will be separated by 3-week washout period.

No treatment for 6 weeks (period B), then splinting at night while sleeping for 6 weeks (period A), then splinting at day and night for 6 weeks (period C). Each treatment period will be separated by 3-week washout period.

No treatment for 6 weeks (period B), then splinting at day and night for 6 weeks (period C), then splinting at night while sleeping for 6 weeks (period A). Each treatment period will be separated by 3-week washout period.

Splinting at day and night for 6 weeks (period C), then splinting at night while sleeping for 6 weeks (period A), then no treatment for 6 weeks (period B). Each treatment period will be separated by 3-week washout period.

Splinting at day and night for 6 weeks (period C), then no treatment for 6 weeks (period B), then splinting at night while sleeping for 6 weeks (period A). Each treatment period will be separated by 3-week washout period.

6-item CTS Symptoms Scale is a 6-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse symptoms. The study will use a Finnish version of The 6-item CTS Symptoms Scale.

6-item CTS Symptoms Scale is a 6-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse symptoms. The study will use a Finnish version of The 6-item CTS Symptoms Scale.

6-item CTS Symptoms Scale is a 6-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse symptoms. The study will use a Finnish version of The 6-item CTS Symptoms Scale.

Change of The Boston Carpal Tunnel Questionnaire Symptom Severity Scale scores (BCTQ SSS) between baseline and 6 weeks of each treatment period

BCTQ SSS is an 11-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse symptoms. The study will use a Finnish version of the BCTQ SSS.

Change of The Boston Carpal Tunnel Questionnaire Symptom Severity Scale scores (BCTQ SSS) between baseline and 1 year

BCTQ SSS is an 11-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse symptoms. The study will use a Finnish version of the BCTQ SSS.

Change of The Boston Carpal Tunnel Questionnaire Functional Status Scale (BCTQ FSS) between baseline and 6 weeks of each treatment period

BCTQ FSS is an 8-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse function. The study will use a Finnish version of the BCTQ FSS.

Change of The Boston Carpal Tunnel Questionnaire Functional Status Scale (BCTQ FSS) between baseline and 1 year

BCTQ FSS is an 8-item questionnaire, with score from 1 to 5 to each of the item, higher score indicating worse function. The study will use a Finnish version of the BCTQ FSS.

BCTQ Total consists of BCTQ SSS and BCTQ FSS, with score from 1 to 5 to each of the item, higher score indicating worse function.

BCTQ Total consists of BCTQ SSS and BCTQ FSS, with score from 1 to 5 to each of the item, higher score indicating worse function.

7-point Likert Scale assesses the improvement of hand symptoms with 7 possible scores: much better, better, somewhat better, no changes, somewhat worse, worse, much worse.

7-point Likert Scale assesses the improvement of hand symptoms with 7 possible scores: much better, better, somewhat better, no changes, somewhat worse, worse, much worse.

Change of The EuroQol 5-dimension (EQ-5D-5L) Health Status and Quality-of-life Measure score between baseline and 6 weeks of each treatment period

Change of The EuroQol 5-dimension (EQ-5D-5L) Health Status and Quality-of-life Measure score between baseline and 1 year

Escape treatments (e.g., corticosteroid injection or any other treatment supervised by medical personnel)

Assessed by participant self-reported information of undergoing or having undergone the escape treatment.

Inclusion Criteria: Clinically confirmed carpal tunnel syndrome (CTS) of any severity level (diagnostic criteria: numbness, pain or paraesthesia in the median nerve distribution area of wrist and fingers), Symptom duration of CTS for at least 3 weeks, No previous corticosteroid injection or surgery during last 6 months, Aged 18 years or older, Able to complete self-report questionnaires electronically, Able to understand Finnish, Willing to join the study and follow the study protocol instructions, Sign informed consent. Exclusion Criteria: Cervical radiculopathy, Other neurological condition affecting the function of the hand such as Multiple Sclerosis, previous nerve injury, Active Rheumatoid arthritis or any other active inflammatory joint disease affecting the hand, Thenar muscle atrophy, Hypothyroidism, Known allergy to any of the splint materials (self-reported by patient), Long term treatment (over 4 months) for CTS with no response, Any other known reason that could prevent from participation for the study time.