title: Endoscopic carpal tunnel release: a 5-year experience.
abstract: BACKGROUND
  Endoscopic carpal tunnel release (ECTR) has gained recognition as an alternative to the current gold standard, the open carpal tunnel release (OCTR). Detailed technical points for the ECTR have not been explained in the literature, especially for surgeons who are considering trying this technique.
  
  
  OBJECTIVE
  In this paper, we present our 5-year experience with the ECTR and special emphasis will be placed on less frequently discussed technical points, such as the optimal site to make the skin incision and the signs to look for in a completely divided retinaculum.
  
  
  METHODS
  In this prospective nonrandomized clinical trial, 176 patients with carpal tunnel syndrome who underwent surgical operation using the Agee uni-portal endoscopic carpal tunnel release technique, over a period of 5 years, were included. The "Hand Questionnaire", a standard questionnaire for hand surgery, was used to evaluate the patients at one, three, six and twelve month post-operative time points. Pain and scar tenderness were measured using the visual analog scale system. We propose the 'most proximally present wrist crease' for the skin incision and the 'proximal to distal sequential division of the retinaculum' as our methods of choice. Two signs, named 'railroad' and 'drop in', are proposed and these will be discussed in detail as hallmarks of complete retinaculum release.
  
  
  RESULTS
  Of the 176 patients who underwent the ECTR operation, 164 cases (93.2%) had no or very little pain at the one year postoperative visit, and nearly all of the patients reported no relapse of symptoms at the previously mentioned postoperative time points. Patient satisfaction and functional recovery was comparable to other published ECTR studies, and showed better short-term results of this technique over the OCTR. One deep seated infection, three cases of transient index finger paresthesia due to scope pressure on the median nerve, and one case of median nerve branch transection, were observed. Scar complications, including; tenderness, redness and pain, were significantly lower in the proximally placed incision in comparison with the distally placed incision (P < 0.005).
  
  
  CONCLUSIONS
  The 'most proximally present wrist crease' and the 'distal to proximal division of the retinaculum' using the two signs of 'railroad' and 'drop in' to confirm a complete division of retinaculum are proposed techniques that should be considered in order to produce good outcomes in ECTR. The 'railroad' sign is the parallel standing of the retinaculum edges, and the 'drop in' sign is the dropping of the retinaculum edge into the scope denote a completely divided retinaculum.
authors.affiliation: Department of Surgery, Firuzgar Medical Center, Iran University of Medical Sciences, Tehran, IR Iran ; Department of Hand Surgery, Mehr Genrel Hospital, Tehran, IR Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Nazerani
authors.affiliation: Trauma Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohamad Hossein
authors.initials: MH
authors.lastname: Kalantar Motamedi
authors.affiliation: Department of Surgery, Firuzgar Medical Center, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Tina
authors.initials: T
authors.lastname: Nazerani
authors.affiliation: Department of Surgery, Firuzgar Medical Center, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Saraii
authors.affiliation: Department of Surgery, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohamad Reza
authors.initials: MR
authors.lastname: Keramati
keywords: Carpal Tunnel Syndrome; Endoscopy; Median Nerve; Nerve Compression Syndromes