A Randomised controlled study comparing short axis and combined short and long axis median nerve hydrodissection for carpal tunnel syndrome

Study will be conducted after the approval by the Institutional Ethics Committee and will be registered in the Clinical Trials Registry- India (CTRI).  Patients will be chosen for the study keeping in mind the inclusion and exclusion criteria. A careful checkup including detailed history with special emphasis on characteristic signs and symptoms of CTS, physical examination, clinical tests which include provocative maneuvers like Phalen test, Tinel test, Durkan test, Upper limb neurodynamic test, hand elevation test and electrodiagonostic test(NCV) will be done. Patients will be classified on the basis of Blands neurophysiological grading of CTS 12 (Annexure – IV). A written informed voluntary consent will be taken from the patient after carefully explaining the procedure, its benefits and risks and alternative therapies in patient’s own language. Median nerve diameter will be assessed in all the patients using ultrasonographic evaluation. All patients will be explained about the Boston Carpal Tunnel Severity Questionnaire (BCTSQ, Annexure – III). Baseline BCTSQ score will be taken in patients before procedure. Patients will be shifted to procedure room and standard monitoring will be applied, including pulse oximetery, electrocardiography and noninvasive blood pressure.

Randomisation

An investigator with no further involvement in the study will generate a list ofrandom numbers between 01-100 in varying block sizes using an online computer randomization service (Research Randomizer www.Randomizer.org). The unique randomization code will be allocated and used to randomize consenting participant patients equally with no restrictions or bias to either of the two study groups: short axis group (A) or combined short and long axis group (B).

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Allocation Concealment

The results of the allocation will be concealed in sequentially numbered sealed opaque envelopes mentioning the code and group number . These envelopes with results of allocation will not be seen by the research coordinator prior to sealing and will only be kept by the coordinator after sealing. On the day of procedure, the coordinator will hand over an envelope to the principal investigator. The approach for the procedure will be decided by the group mentioned in the envelope. Case record sheet filled subsequently will only mention the randomized code with no reference to the approach or group number noted.

For group A (Short axis approach) - The needle and probe are both perpendicular to the nerve. The needle is in plane to the transducer and the soft tissues below the nerve are first hydrodissected (with the needle bevel facing up) followed by hydrodissection of soft tissues above the nerve (with the needle bevel facing down).

 For group B (Combined short and long axis approach) - First the needle and probe are both perpendicular to the nerve and hydrodissection is done similar to the short axis approach. Subsequently both the transducer and needle are turned parallel to the nerve and soft tissue below and above the nerve are hydrodissected. This allows us to hydrodissect a long segment of the nerve in both proximal and distal direction.

 The injectate used in both the situations is 20ml of 5% dextrose with water.

 Serious adverse events (such as swelling, pain, bleeding, increased paresthesia or numbness, injury to neighbouring neurovascular structures) will be noted, managed and reported to the IEC within 24 hours.