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NCT Number: NCT07614425

Finnish Carpal Tunnel Surgery Study

Carpal tunnel syndrome (CTS) is a common condition caused by pressure from a ligament on a nerve in the wrist, leading to pain, numbness, and weakness in the hand. Surgery to cut the ligament is often recommended when non-surgical treatments do not provide sufficient symptom relief, but it is unclear how much of the improvement is due to the surgery itself versus natural recovery or placebo effects.

The FINCATS study will compare standard carpal tunnel surgery with a placebo procedure in which the ligament is not cut. Participants and the healthcare staff caring for them after the procedure will not know which procedure was performed. The study's main question is whether cutting the ligament provides greater symptom relief than a placebo procedure. In addition, eligible patients who are not willing to participate in randomized setting are invited to join a parallel observational group. Participants in this observational group are treated within usual care pathway.

Participants in both the randomized and observational group will be followed for five years to assess symptom improvement, hand function, pain, quality of life, and any side effects. The goal is to provide reliable evidence to help patients and doctors make informed decisions about treatment.

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Key information

Conditions

Carpal Tunnel Syndrome Cumulative Trauma Disorders Median Neuropathy Mononeuropathies Nerve Compression Syndromes Nervous System Diseases Neuromuscular Diseases Peripheral Nervous System Diseases Sprains and Strains Wounds and Injuries

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

HUS group, Helsinki Central University Hospital, Meilahti Bridge Hospital, Helsinki, Finland

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18-75 years
  • Clinical manifestations of carpal tunnel syndrome: paresthesia and /or hypoesthesia in the distribution of the median nerve, possibly pain
  • Electrodiagnostically (ENMG or ENEG) verified compression of the median nerve at the carpal tunnel in the wrist, performed no more than a year before recruitment.
  • Duration of symptoms 3 months or longer
  • Patient living independently
  • Patient has not responded to the use of a resting splint supporting the wrist, nor to other possible conservative forms of treatment
  • Patient able and willing to give consent
  • The patient is willing to undergo surgical treatment for carpal tunnel syndrome.
  • The patient has access to a device that can be used to complete electronic symptom questionnaires.

Exclusion criteria

  • Work disability
  • Clinical findings of Abductor Pollicis Brevis atrophy
  • Symptoms and Electrodiagnostic findings of some other peripheral neural entrapment than carpal tunnel syndrome
  • Rheumatoid arthritis or other forms of systemic inflammatory disease
  • Diagnosed dementia
  • Neurologic disorders affecting the function of the hand
  • Other untreated systemic disorders or diseases with poor therapeutic balance: hypertension, epilepsy, pulmonary or cardiac disease, liver or renal insufficiency, diabetes mellitus, hypothyroidism, psychiatric disease
  • Other causes of pain and paresthesia in the hand
  • Previous trauma of the hand or wrist (e.g. distal radius fracture), which has resulted in compromised hand function
  • Previous carpal tunnel release in either hand
  • Previous nerve injury to the upper limb or cervical spine

Treatment and study plan

Carpal tunnel release

Procedure

Open carpal tunnel release: skin incision, division of the palmar aponeurosis, and transverse carpal ligament.

Placebo surgery

Procedure

Skin incision and division of the palmar aponeurosis

Primary outcomes

  1. Patient acceptable symptom state (PASS)

    Time frame: 4 months

    PASS is used as a binary global outcome using the following question:

    "Regarding your recovery from the carpal tunnel release, specifically pertaining to paresthesia, pain and overall function of the hand, would you be content if the clinical state of your hand would remain the same as it has been the past week?" Response options are: Yes, I would be content or No, I would not be content.

Secondary outcomes

  1. Patient acceptable symptom state (PASS)

    Time frame: 6 and 9 months and 1,2,3,4 and 5 years

    PASS is used as a binary global outcome measure and will be assessed using the following question:

    "Regarding your recovery from the carpal tunnel release, specifically pertaining to paresthesia, pain and overall function of the hand, would you be content if the clinical state of your hand would remain the same as it has been the past week?" Response options are: Yes, I would be content or No, I would not be content.

  2. Global Impression of Improvement (PGI-I)

    Time frame: 4, 6 and 9 months and 1,2,3,4 and 5 years

    A single-item patient-reported measure indicating overall perceived improvement since the start of treatment, rated on a 7-point scale from 1 (very much improved) to 7 (very much worse).

  3. 6-Item carpal tunnel syndrome (CTS) symptoms scale

    Time frame: At recruitment, 4, 6 and 9 months and 1,2,3,4 and 5 years

    The CTS-6 is a validated six-item patient-reported questionnaire used to assess the severity of carpal tunnel syndrome symptoms, including pain, numbness or tingling, and functional impairment, with scores ranging from 0 (least severe) and 26 (most severe). A score >12 correlates with an 80% probability of CTS.

  4. Patient-Specific Functional Scale (PSFS)

    Time frame: At recruitment, 4, 6 and 9 months and 1,2,3,4 and 5 years

    The Patient-Specific Functional Scale (PSFS) is a patient-reported measure that assesses level of functional limitations in 3-5 activities identified as important by the patient and deemed difficult to perform by the patient, due to the hand condition. The PSFS is rated on an ordinal scale from 0 (unable to perform the activity) to 10 (able to perform the activity at the same level as before the disease.)

  5. Numeric Pain Rating Scale (NRS)

    Time frame: At recruitment, 4, 6 and 9 months and 1,2,3,4 and 5 years

    A patient-reported measure for pain intensity on an 11-point scale from 0 (no pain) to 10 (worst imaginable pain).

  6. Health-related quality of life (EuroQol 5-Dimension 5-Level (EQ-5D-5L) index value)

    Time frame: At recruitment, 4, 6 and 9 months and 1,2,3,4 and 5 years

    EQ-5D-5L questionnaire, Finnish language version, using the Danish value set. Score ranges from values below 0 (health states considered worse than death) to 1.00 (full health), where higher scores indicate better health-related quality of life.

  7. Health-related quality of life: EuroQol 5-Dimensions (EQ-5D) Visual Analogue Scale (VAS) (EQ VAS) )

    Time frame: At recruitment, 4, 6 and 9 months and 1,2,3,4 and 5 years

    EQ-5D is a generic patient rated outcome measure (PROM) comprising five health dimensions (mobility, self-care, daily activities, pain/discomfort, anxiety/depression) and a VAS. EQVAS is a vertical visual analogue scale, on which patients rate their general health on a scale from 0 (worst imaginable health state) to 100 (best imaginable health state).

  8. Harms

    Time frame: Intervention (intra-operative), at 4, 6 and 9 months and 1,2,3,4 and 5 years. In addition, unprompted contacts from participant

    Harms and healthcare contacts related to the operated hand will be collected systematically and unprompted using a standardized electronic case report files (eCRF). Events will be classified by type (Adverse event, Serious Adverse Event, Suspected Unexpected Serious Adverse Reaction), attribution, timing, and nature.

Other outcomes

  1. Pillar pain - interview

    Time frame: At recruitment and 1 and 4 months after intervention.

    Pillar pain will be assessed using two questions:

    • Do you have pain at rest in the palm of your hand?
    • Are you able to bear weight on your extended wrist and hand? Response options: Yes or No.

  2. Pillar pain - pressure pain thresholds

    Time frame: At recruitment and 1 and 4 months after intervention.

    Pillar pain will be assessed through pressure pain thresholds on thenar and hypothenar eminences with a digital algometer

  3. Pillar pain - palmar skin sensation

    Time frame: At recruitment and 1 and 4 months after intervention.

    Palmar skin sensation will be assessed at thenar and hypothenar eminences with a standard evaluation tool neuropen.

  4. Blinding fidelity

    Time frame: At 4 months after intervention.

    Blinding fidelity will be assessed by asking participants which treatment group they believe they were allocated to. Response options will include "Carpal tunnel release," "Placebo intervention," or "Unsure."

  5. Conduction velocity

    Time frame: At 4 months after intervention.

    Nerve conduction velocities will be assessed in randomized participants using standard electroneurography techniques. Measurements will quantify median nerve function across the carpal tunnel to evaluate changes after intervention.

  6. Medication

    Time frame: At recruitment, 4, 6 and 9 months and 1,2,3,4 and 5 years

    Need for medication due to pain. Response options: Every day, On most days of the week, 1-2 times a week, Rarely 5. Never

  7. Clinical examination

    Time frame: At recruitment; at 4, and 12 months; and at 5 years after primary surgery.

    Standard hand surgical clinical examination and provocation tests: Tinell, Tethro, Phalen and atrophy evaluation

Study contacts

Contact information is provided by the study sponsor or research team.

Kati MJ Jaatinen

CONTACT

[email protected]

Susanna Stjernberg-Salmela, MD, PhD

CONTACT

[email protected]

0504274955 ext. +358

Sponsors and collaborators

Lead sponsor

Helsinki University Central Hospital

Other

Registry information

Official study title

Finnish Carpal Tunnel Study - a Randomised, Placebo-surgery Controlled Trial

Acronym: FINCATS

Important dates

Study start
2026
Primary completion
2029
Study completion
2035
First posted
May 29, 2026
Registry last updated
Jun 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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