Erdmann 1994.

Methods	RCT
Participants	Mean age 53 years. 73% female. Mean duration of symptoms 24 months. Electrophysiologically confirmed CTS, both idiopathic and secondary CTS. 34 out of 71 patients treated bilaterally (25 patients 1 hand ECTR, 1 hand OCTR simultaneously).
Interventions	(1) ECTR: two‐portal extrabursal Chow technique (53 hands). (2) OCTR (52 hands).
Outcomes	Pain. Return to work. Complications.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear