Purpose: The objective of this study was to ascertain whether endoscopic carpal tunnel release (ECTR) is indicated for treatment of carpal tunnel syndrome accompanied by thenar muscle atrophy.
Type of study: Prospective cohort study.
Methods: Two-portal ECTR was performed on 67 hands in 52 patients with carpal tunnel syndrome accompanied by thenar muscle atrophy.
Results: Preoperative severity of thenar muscle atrophy was severe in 24 hands, moderate in 23 hands, and mild in 20 hands. Postoperative severity of thenar muscle atrophy was severe in 6 hands, moderate in 2 hands, mild in 23 hands, and none in 36 hands.
Conclusions: Improvements with thenar muscle function in most cases of carpal tunnel syndrome can be expected with 2-portal ECTR.
Level of evidence: Level IV.