Reply to "Analgesic Effect of Gabapentin on Post-Operative Pain After Arthroscopic Anterior Cruciate Ligament Reconstruction"



Orthopedic Department, Guilan Road Trauma Research Center, Guilan University of Medical Sciences, Rasht, Iran


In Reply
Dr. Ortiz and Dr. Romero-Quezada evaluated our study precisely and authors are grateful for their great survey on our article. There were some questions and concerns that we are going to answer. We wish it could help others to come up with better ideas and conclusions.
1. ACL tear may occur in two scenarios and we believe that there is not a third one: 1st- the ACL injury functionally disables the patient and becomes symptomatic; in this scenario the patient would suffer from giving way and the “Lachman test” is definitely positive (3+ or 4+) (1). Intra-operatively (post anesthesia) “Pivot shift test” is almost positive in all cases. 2nd- ACL injury does not conflict with the patient’s routine and social activity and giving way are usually negative and Lachman test can be negative, 1+ and in the most severe condition 2+ positive. Partial ACL tear may be reported in MRI, however authors believe these cases do not benefit from a surgical intervention, and conservative treatment should be performed.
2. Although most of our patients were suffered from sports trauma, mechanisms of ACL tears were not the same in all patients. The duration between traumas to surgeries in all patients enrolled in this study were at least 6 weeks which were included the proceeding from acute trauma phase to performing physical therapy and accomplishing full range of motion pre-operatively. Since the present study was not about surgical technique and pre or post rehab protocols and programs, authors avoided such additional issues.
3. About Pethidine issue, this drug is the main protocol one in our hospital to provide analgesics for post-operative pain, so authors routinely decided to utilize the pethidine as analgesics such as recent relative article (2). We used the pethidine intravenously and by patient’s demand; if a patients requested for pain killers, we provided him/her with 0.5 mg-per-Kg pethidine which was injected intravenously. The time and amount of requested pethidine for every patient were different and patient-dependent and were registered in the medical file for further evaluations.
4. Since randomization was performed prior to surgery, all eligible cases were first randomized in the intervention or control groups. So to our knowledge, primary demographic characteristics were better to contain all eligible case rather than those who remained in the trial. If we would demonstrated the data, as you had commented, one may object that the data is not complete and how can someone be sure about the randomization, so we prefer to put all the data.
5. The criticism about table 2 is correct. The table we have sent to the journal has been probably mis-typed during the publishing process. The original table is attached to the end of this manuscript. Your comment about the table 3 is correct again; it is the mean pethidine consumption during the first 6 and 24 hour (in milligrams).
6. The main purpose of this study is to apply another agent to decrease the opioid consumption after arthroscopic surgeries such as recent works (3, 4). It was the main reason of utilizing Gabapentin as an adjuvant to the pethidine to evaluate whether it could facilitate the decrease of opioid consumption and its complication.
Finally authors wanted to show their appreciations to Dr. Ortiz and Dr. Romero-Quezada for their precise and meticulous comments.


  1. Wiertsema SH, van Hooff HJ, Migchelsen LA, Steultjens MP. Reliability of the KT1000 arthrometer and the Lachman test in patients with an ACL rupture. Knee. 2008;15(2):107-10.

  2. Bang SR, Yu SK, Kim TH. Can gabapentin help reduce postoperative pain in arthroscopic rotator cuff repair? A prospective, randomized, double-blind study. Arthroscopy. 2010;26(9):106-11.

  3. Clarke H, Kirkham KR, Orser BA, Katznelson R, Mitsakakis N, Ko R, et al. Gabapentin reduces preoperative anxiety and pain catastrophizing in highly anxious patients prior to major surgery: a blinded randomized placebo-controlled trial. Can J Anaesth. 2013;60(5):432-43.

  4. Mathiesen O, Moiniche S, Dahl JB. Gabapentin and postoperative pain: a qualitative and quantitative systematic review, with focus on procedure. BMC Anesthesiol. 2007;7:6.