postoperative pain is a critical concern affecting the choice between open and endoscopic surgical techniques and it is the main outcome parameter in both techniques . thus , postoperative pain is frequently assessed in studies comparing the results of open and endoscopic release in carpal tunnel syndrome ( cts ) , a common peripheral nerve entrapment . while several parameters such as functional outcome , recovery time , scar sensitivity and complication rates are also addressed in these studies , none of them focused on a scheduled and periodical followup of pain intensity in the early postoperative period.1234 the aim of this prospective , randomized , controlled study was to compare the course of pain intensity in the early postoperative period in patients undergoing open carpal tunnel release ( octr ) versus those undergoing endoscopic carpal tunnel release ( ectr ) . eighty two patients , clinically and electrophysiologically diagnosed with cts , were included in this study . the type of surgery to be performed was decided using a  random number generator  software ( research randomizer , version 3.0 . urbaniak gc , plous s : [ computer software ] . retrieved on april 22 , 2010 , from http://www.randomizer.org ) . patients were randomized into two groups ; endoscopic surgery group [ ( 21 female , 1 male ; mean age 49 years ( range 3164 years ) ] and open surgery group [ ( 25 female , 3 male ; mean age 45.1 years ( range 2968 years ) ] and received carpal tunnel release [ table 1 ] . demographics of study population inclusion criteria were complaints of cts for at least 3 months which did not respond to conservative treatment , electrophysiological findings of intermediate to advanced level of isolated median nerve involvement in the carpal tunnel , lack of motor deficit , absence of cervical disc pathology , absence of metabolic problem resulting in peripheral neuropathy , lack of previous upper extremity injury or surgery and lack of movement restriction in the wrist and hand . preoperative physical examination and boston cts scale of patients was performed by the same surgeon.5 the preoperative electrophysiological assessment was repeated in accordance with the study protocol by the same neurologist . the electrophysiological evaluation was conducted using a nihon - kohden meb 5504 k device in the electromyography laboratory at the department of neurology in our hospital . all patients received preoperative regional intravenous anesthesia ( riva ) with the same pharmacological agents ( prilocaine hydrochloride 3 mg / kg citanest ; astrazeneca ; complemented with 0.9% nacl for a 40 cc solution ) . an incision of 34 cm long , 2 mm ulnar to the thenar crease line and distal to the kaplan oblique line was made . the superficial palmar fascia and the transverse carpal ligament was cut through the ulnar side while protecting the median nerve and its motor branch . the skin and subcutaneous tissue was released proximally and distally with a retractor , the opening of the tunnel was confirmed . a second line was drawn proximally from the end of this first line 0.5 cm . after that , a third line was drawn from the proximal end of the second line radially 1 cm which determined the entry portal . for exit a transverse line from the distal end of the abducted thumb and a longitudinal line between the 3 and 4 finger toward the proximally was drawn in the palm surface . a gap was created between the transverse carpal ligament ( tcl ) and the ulnar bursa with the help of a curved dissector after the proximal border of the tcl was determined . tcl was visualized with an endoscope and divided with a retrograde knife ( ectra 2 ; smith and nephew ) . a compression bandage was applied to control postoperative bleeding and released 30 min after surgery in all patients . patient 's pain level was assessed on the 1 , 2 , 4 and 24 postoperative hours using visual analog scale ( vas ) scores . pain relief was achieved with orally administered paracetamol 500 mg tablets ( parol tb , atabay ila ) . the total dose of postoperative medication in the first 24 h was noted . data were analyzed using the spss for windows ( version 15.0 ) , chicago , usa , spss inc . for the assessment of the study data , beside descriptive statistical methods ( average , standard deviation , median , frequency , ratio , minimum , maximum ) , independent samples t - test was used for comparing the normally distributed parameters between the groups and the mann whitney u - test was used for comparing the nonnormally distributed parameters between the groups in the comparison of quantitative data . repeated measures test was used to analyze the change of the vas score according to followup time . the significance of the difference between pre and postoperative mean values was analyzed with paired samples t - test . an incision of 34 cm long , 2 mm ulnar to the thenar crease line and distal to the kaplan oblique line was made . the superficial palmar fascia and the transverse carpal ligament was cut through the ulnar side while protecting the median nerve and its motor branch . the skin and subcutaneous tissue was released proximally and distally with a retractor , the opening of the tunnel was confirmed . a second line was drawn proximally from the end of this first line 0.5 cm . after that , a third line was drawn from the proximal end of the second line radially 1 cm which determined the entry portal . for exit a transverse line from the distal end of the abducted thumb and a longitudinal line between the 3 and 4 finger toward the proximally was drawn in the palm surface . a gap was created between the transverse carpal ligament ( tcl ) and the ulnar bursa with the help of a curved dissector after the proximal border of the tcl was determined . tcl was visualized with an endoscope and divided with a retrograde knife ( ectra 2 ; smith and nephew ) . a compression bandage was applied to control postoperative bleeding and released 30 min after surgery in all patients . patient 's pain level was assessed on the 1 , 2 , 4 and 24 postoperative hours using visual analog scale ( vas ) scores . pain relief was achieved with orally administered paracetamol 500 mg tablets ( parol tb , atabay ila ) . the total dose of postoperative medication in the first 24 h was noted . data were analyzed using the spss for windows ( version 15.0 ) , chicago , usa , spss inc . for the assessment of the study data , beside descriptive statistical methods ( average , standard deviation , median , frequency , ratio , minimum , maximum ) , independent samples t - test was used for comparing the normally distributed parameters between the groups and the mann whitney u - test was used for comparing the nonnormally distributed parameters between the groups in the comparison of quantitative data . repeated measures test was used to analyze the change of the vas score according to followup time . the significance of the difference between pre and postoperative mean values was analyzed with paired samples t - test . an incision of 34 cm long , 2 mm ulnar to the thenar crease line and distal to the kaplan oblique line was made . the superficial palmar fascia and the transverse carpal ligament was cut through the ulnar side while protecting the median nerve and its motor branch . the skin and subcutaneous tissue was released proximally and distally with a retractor , the opening of the tunnel was confirmed . a second line was drawn proximally from the end of this first line 0.5 cm . after that , a third line was drawn from the proximal end of the second line radially 1 cm which determined the entry portal . for exit a transverse line from the distal end of the abducted thumb and a longitudinal line between the 3 and 4 finger toward the proximally was drawn in the palm surface . a line bisecting this right angle was extended 1 cm from the vertex toward the ulna . a gap was created between the transverse carpal ligament ( tcl ) and the ulnar bursa with the help of a curved dissector after the proximal border of the tcl was determined . tcl was visualized with an endoscope and divided with a retrograde knife ( ectra 2 ; smith and nephew ) . a compression bandage was applied to control postoperative bleeding and released 30 min after surgery in all patients . patient 's pain level was assessed on the 1 , 2 , 4 and 24 postoperative hours using visual analog scale ( vas ) scores . pain relief was achieved with orally administered paracetamol 500 mg tablets ( parol tb , atabay ila ) . the total dose of postoperative medication in the first 24 h was noted . data were analyzed using the spss for windows ( version 15.0 ) , chicago , usa , spss inc . for the assessment of the study data , beside descriptive statistical methods ( average , standard deviation , median , frequency , ratio , minimum , maximum ) , independent samples t - test was used for comparing the normally distributed parameters between the groups and the mann whitney u - test was used for comparing the nonnormally distributed parameters between the groups in the comparison of quantitative data . repeated measures test was used to analyze the change of the vas score according to followup time . the significance of the difference between pre and postoperative mean values was analyzed with paired samples t - test . the mean age of the patients was 45.1  8.54 ( range 3168 years ) years in the open surgery and 49  8.21 ( range 3164 years ) years in the endoscopy group ; both groups were similar ( p = 0.11 ) . there were three ( 10.7% ) male and 25 ( 89.3% ) females in the open surgery group . the endoscopic surgery group had one male ( 4.5% ) and 21 females ( 95.5% ) patients . mean preoperative duration of complaint was 47.96  50.43 ( range 3180 months ) months in the open surgery and 59.55  57.18 ( range 4180 months ) months in the endoscopic surgery group . twenty one patients ( 75% ) in the open surgery group and 17 ( 77.3% ) in the endoscopic surgery group were operated on their right upper extremity . seven patients ( 25% ) in the open surgery group and 5 ( 22.7% ) in the endoscopic surgery group were operated on their left upper extremity . the boston questionnaire assesses the severity of the symptoms and functional capacity of the patients . there was no statistical difference between the groups in terms of both pre and postoperative boston scores . a significant difference was observed between the pre and postoperative 6 week boston scores of the two groups [ tables 2 and 3 ] . pre and postoperative boston scores of open surgery patients pre and postoperative boston scores of endoscopic surgery patients nocturnal complaints of all patients receded in the early postoperative period . pain assessment at the postoperative 1 , 2 , 4 and 24 hours revealed significantly low vas scores in the endoscopic surgery group [ table 4 ] . the changes of vas scores according to followup were found statistically insignificant for both groups ( p = 0.445 , p = 0.264 ; p > 0.05 ) . the first analgesic intake requirement in the open surgery group was at 3.81 cumulative dose of paracetamol intake during the first 24 h postoperative period was 772.72  428.93 mg in the endoscopic group and 1 , 535.71  428.79 mg in the open surgery group . postoperative pain assessment results with vas one patient in the endoscopic surgery group experienced a flexor digitorum superficialis injury of the 5 finger . the injury was detected peroperatively and the tendon was primarily repaired by expanding the incision . examination at the postoperative 6 week revealed scar pain in three patients in the open surgery group . this prospective , randomized and controlled study was undertaken to compare the course of pain intensity in the early postoperative period in patients undergoing octr and ectr . both open and endoscopic techniques can be used for carpal tunnel release in refractory cases of carpal tunnel syndrome.1 skin problems are one of the drawbacks of open release and can be reduced with the endoscopic technique.26789 in our study , one patient in the endoscopic surgery group experienced a flexor digitorum superficialis injury of the 5 finger , which was detected peroperatively and was repaired primarily by expanding the incision . 2014 ) reported in his meta - analysis that ectr appears to be associated with fewer minor complications compared to octr , but there was no difference in the rates of major complications.10 in another current meta analysis , the risk of nerve injury was found to be higher in endoscopically treated patients , whereas the scar tenderness was less common.11 the findings were supported by keith 's study.12 to the best of our knowledge , postoperative pain after endoscopic and octrs has not been compared . in their studies , atroshi , chow and hantes and agee et al . emphasized the low postoperative level of pain but reported subjectively.131415 standard pain scoring was not performed in both studies.131415 in our study , postoperative pain was analyzed in detail using the vas score . the pain level in the endoscopic surgery group during the first 24 h after surgery group was low . meta analysis did not showed any difference between octr and ectr regarding to functional outcome.101112 however , less postoperative pain and faster recovery have been reported following endoscopic release when compared with open technique,3 disadvantages of ectr , including high surgical complication , inability to perform synovectomy , inability to detect space occupying lesions in the carpal tunnel and high cost have been reported in the literature.16 chow and hantes ( 2002 ) demonstrated that patients required 02 tablets of analgesics after endoscopic carpal tunnel surgery . however , the type of analgesic or its dosage is not mentioned in their study.15 functional capacity of the patients can also be improved.41718192021 in our study , carpal tunnel symptoms disappeared in both patient groups . 2013 ) reported in his study that the pain relief immediately after surgery and after discharge from hospital was also similar for octr and ectr.22 whereas , our results showed that postoperative pain intensity is significantly less after ectr however , the pain assessment was subjective , momentary and unscheduled . also , the amount of analgesic medication was used to compare pain intensity , rather than standardizing the analgesic regimen between the groups . our study highlights the need for a more comprehensive investigation in which large patient groups are used to determine whether there is a statistically significant difference between two groups .