An interventional study of Carpal tunnel release and Combined carpal tunnel and lacertus release in Carpal Tunnel Syndrome (CTS) and Lacertus Syndrome, sponsored by Maasstad Hospital. Recruiting at 2 sites in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-26.
Sponsored by Maasstad Hospital · Not applicable, Interventional, and Treatment
Carpal tunnel syndrome (CTS) is a condition that can cause pain, numbness, or tingling in the hand and wrist. The most common surgery for CTS is called carpal tunnel release, which aims to relieve pressure on the main nerve in the wrist.
However, after this surgery, some patients (up to 4 out of 10) still have symptoms, and about 1 in 8 may need another surgery. One reason symptoms can continue is that the nerve may also be compressed higher up in the arm, near a ligament called the Lacertus fibrosus. Releasing this area might help, but it is often not checked or treated during the first surgery because current tests (like physical exams, nerve studies, and ultrasounds) cannot reliably detect it.
This study is comparing two approaches for people with CTS:
The goal is to see which surgery helps patients feel better and have fewer symptoms in the hand and wrist after treatment.
Carpal tunnel release is the most commonly performed surgical procedure in patients diagnosed with carpal tunnel syndrome (CTS). Nevertheless, up to 43% of patients experience residual symptoms, necessitating secondary surgical interventions in approximately one out of eight carpal tunnel releases.
These residual symptoms may be attributable to proximal median nerve compression (PMNC), which can potentially be alleviated by performing a Lacertus release. However, diagnosing PMNC poses a challenge, as standard diagnostic tools like physical examination, electromyography (EMG) and ultrasound lack the specificity to distinguish between CTS and PMNC. Consequently, PMNC often goes undetected and untreated during initial evaluations.
This randomised trial compares patient reported outcomes following median nerve decompression at the carpal tunnel alone versus median nerve decompression at both the carpal tunnel and the Lacertus fibrosus in individuals with CTS.
587 studies on the registry are indexed under Carpal Tunnel Syndrome; 134 are open to participants now.
This study's planned enrollment of 110 is above the median of 60 across 443 interventional studies indexed under Carpal Tunnel Syndrome.
Browse Carpal Tunnel Syndrome studies →Maasstad Hospital is the lead sponsor of 21 studies on the registry; 5 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Control group
Procedure: Carpal tunnel release
Intervention group
Procedure: Combined carpal tunnel and lacertus release
Carpal tunnel release is a surgical procedure to treat carpal tunnel syndrome by cutting the ligament (transverse carpal ligament) covering the wrist's carpal tunnel. This action relieves pressure on the median nerve, alleviating pain, numbness, and weakness in the hand. It is usually an outpatient procedure done under local anesthesia.
A transverse incision is made on the forearm's volar (anterior) aspect, approximately 3cm distal of the elbow crease. This incision is placed over the palpable brachioradialis and biceps tendon. The subcutaneous tissue is dissected to expose the fascia overlying the flexor pronator muscles. The brachial fascia is identified and incised to reveal the underlying Lacertus fibrosus (also known as the bicipital aponeurosis). The Lacertus fibrosus is a tendinous band extending from the biceps tendon medially across the forearm. Care is taken to avoid injury to the underlying structures, particularly the median nerve, which lies deep and slightly medial to the Lacertus fibrosus. The Lacertus fibrosus is incised transversely. The surgeon ensures that the median nerve is fully decompressed and that there are no remaining constrictive bands. It is usually an outpatient procedure done under local anesthesia.
Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ SSS)
Scores range from 1 to 5. A higher score indicates a more severe level of impairment or discomfort.
Time frame: At twelve months follow-up
Boston Carpal Tunnel Questionnaire Functional Status Scale (BCTQ FSS)
Scores range from 1 to 5. A higher score indicates a more severe level of impairment or discomfort.
Time frame: From enrollment until 12 months of follow-up
Anchor questions
Regarding patient satisfaction to analyse minimal clinically important difference (MCID)
Time frame: At 12 months follow-up
Number of participants with residual, persistent en recurrent CTS symptoms
Time frame: From 6 weeks after surgery until 12 months of follow-up
Pillar pain
The presence of tenderness or pain in the thenar or hypothenar area around the hook of the hamate and the unciform process of the trapezium
Time frame: From 6 weeks after surgery until 12 months of follow-up
Number of participants undergoing secondary surgery
This includes, but is not limited to, nerve decompression, internal or external neurolysis, and flap reconstruction in the ipsilateral arm.
Time frame: From 6 weeks until 12 months of follow-up.
Number of participants that experienced complications or adverse events
Such as infection, seroma, and tendon and neurovascular damage.
Time frame: From enrollment until 12 months of follow-up.
(Return to) work using the QuickDASH work module.
Time frame: From enrollment until 6 months of follow-up.
Sensibility
Monofilament test on the tuft of the 3rd digit and the proximal thenar. The tuft of the 5th digit and the distal thenar will be measured and used as a reference.
Time frame: From enrollment until 12 months of follow-up.
Tip-pinch strength
Tip-to-tip pinch strength of the first and second digit will be measured with a baseline pinch gauge.
Time frame: From enrollment until 12 months of follow-up
Cost-effectiveness of intervention
Measured with health care resource utilisation and costs (iMCQ, iPCQ).
Time frame: From enrollment until 12 months of follow-up
5-level EuroQol (EQ-5D-5L): Quality of life
Will be assessed using the 5-level EuroQol (EQ-5D-5L) questionnaire.
Time frame: Will be assessed at baseline and at 12 months of follow-up.
Physical examination
OK-sign, FLP and FDP2 strength separately (compared to contralateral hand). Scratch collapse test over the carpal tunnel and Lacertus fibrosis (positive or negative). Phalen and Tinel test (positive or negative).
Time frame: From enrollment until 12 months of follow-up.
Exploratory ultrasound
Changes in median nerve cross-sectional diameter (mm) to evaluate postoperative changes in nerve size over time, measured by nerve ultrasound.
Time frame: Will be assessed at baseline and 3 months.
Patient Demographics
Age, sex, labour (blue versus white collar), hand dominance and medical history regarding comorbidities and hand-specific conditions
Time frame: At baseline
PDFs hosted by the registry, ClinicalTrials.gov.
Started May 2026 (actual). Primary completion is estimated for Feb 2028, 21 months after the start.
Of 251 non-industry interventional studies with no phase under Carpal Tunnel Syndrome, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 27. This study's planned 21 months is above that.
Counting every sponsor, half of 261 studies reached it within 12 months; a quarter within 7 and three quarters within 26.
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