Adductor Canal Vs Adductor Canal Plus SPANK Block for Postoperative Pain in Knee Arthroplasty Surgery


This study will prospectively investigate the efficacy of Adductor canal block with periarticular infiltration Vs Adductor canal block, Periarticluar infiltration and Sensory posterior articular nerve of the knee block in patients undergoing total knee arthroplasty. The study will aid in answering question whether SPANK block is an effective adjunct in preventing posterior knee pain without causing motor blockade.

Full Title of Study: “A Prospective Randomized Parallel Study to Compare Post-operative Pain Control With Addition of Sensory Posterior Articular Nerve Block to Adductor Canal Block (SPANK) and Intraoperative Periarticular Infiltration in Total Knee Arthroplasty.”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Single (Outcomes Assessor)
  • Study Primary Completion Date: March 15, 2021

Detailed Description

Total knee arthroplasty (TKA)is a common orthopedic surgical procedure. Optimal pain control is necessary for early recovery and discharge. TKA is considered one of the more painful surgical procedures, peripheral nerve blocks and multimodal analgesia are incorporated into clinical practice to provide patient comfort, decrease postoperative opioid requirement, facilitate early ambulation and enhance patient satisfaction.Adductor canal nerve block (ACB) and intraoperative periarticular infiltration (PAI) are routine clinical practice followed at our institute for postoperative pain control. Although ACB provided analgesia to peripatellar and anterior intra-articular aspect of knee joint, it does not relieve posterior knee pain which can be moderate to severe in intensity. Many techniques have been employed for posterior knee pain including sciatic nerve block and infiltration between popliteal artery and posterior capsule of the knee joint (IPACK) with limited success. Sciatic nerve block is considered gold standard but is rarely used due to associated motor weakness, which may delay ambulation and decrease participation in physical therapy postoperatively . In recent times IPACK block has gained popularity but there are concerns about local anesthetic injection close to surgical field and total dose of local anesthetic exceeding the recommended amount if combined with periarticular infiltration as is the practice at our institute. SPANK block was described in 2015 by Kardash et al for posterior knee pain while sparing motor function. The block is performed at the level of femoral shaft above the femoral epicondyle, on the medial side of the leg, with needle positioned just superficial to posteromedial femoral periosteum and 15 ml of local anesthetic is injected, decreasing concerns for local anesthetic toxicity, and invasiveness close to surgical field as compared to IPACK block which requires 30 ml of local anesthetic. Efficacy of SPANK block has been demonstrated as rescue analgesic for posterior knee pain after TKA, and a trial is underway to evaluate efficacy of ACB an SPANK block versus ACB alone [5].There is no literature evaluating benefit of SPANK block when added to ACB and PAI which is a standard practice. If SPANK block proves to be effective in controlling posterior knee pain, with motor sparing effect it can help reduce postoperative opioid requirement, help achieve same day discharge and prove to be another small step towards fighting opioid epidemic. Hence, we propose this study to evaluate added benefit of SPANK block to ACB and PAI with regards to postoperative pain control.


  • Procedure: adductor canal block
    • The block is performed in supine position under ultrasound guidance using 22 G Touhy needle advanced in plane and 15 cc of 0.5% Ropivacaine ( local anesthetic) with dexmedetomidine 20-30 mcg depending on the age of the patient is injected at midthigh level lateral to the femoral artery in adductor canal to provide sensory blockade to the anterior aspect of the knee.
  • Procedure: SPANK
    • SPANK: The block is performed in supine position, using 22 G Touhy needle, under ultrasound guidance, needle is advanced in plane to posteromedial shaft of femur taking care to avoid popliteal artery, and 0.5% ropivacaine 15 cc, dexmedetomidine 20-30mcg and dexamethasone 4 mg is injected into inner thigh above the knee provide sensory block to posterior aspect of the knee.
  • Drug: Ropivacaine
    • ropivacaine 0.5% will be use in the block

Arms, Groups and Cohorts

  • Active Comparator: Adductor canal block (ACB)
  • Experimental: Adductor canal block plus SPANK block

Clinical Trial Outcome Measures

Primary Measures

  • Pain score using Numerical rating Scale (NRS) with ambulation at 24 hours after total knee arthroplasty
    • Time Frame: At 24 hours after surgery
    • Patient will describe the pain experienced after surgery on a scale from 1-10 being 10 the worst pain ever experienced, this will be registered in the format designed for this purpose and at the end of the study will be analyzed

Secondary Measures

  • Pain scores at rest and with movement at 6, 12 and 24 hours after the surgery measured using Numerical Rating Scale (NRS).
    • Time Frame: It will be measured at 6 hours, 12 hours, 24 hours after surgery
    • Patient will describe the pain experienced after surgery in rest and in movement at 6,12,24 hours on a scale from 1-10 being 10 the worst pain ever experienced.
  • Time to first opioid Consumption
    • Time Frame: During the first 24 after surgery
    • The amount of time measured from the end of the surgery when the patient leaves the operating room to the time when they receive their first dose of any opioid medication.
  • Opioid consumption
    • Time Frame: During the first 24 after surgery
    • will be measured using morphine equivalents during first 24 hours after knee surgery, starting when the patient leaves the operating room
  • Extent of motor blockade in various lower extremity muscle groups
    • Time Frame: During the first 24 after surgery
    • This outcome will be reported by physical therapy on medical records
  • Time that the patient takes to walk 100 feet after surgery
    • Time Frame: During the first 24 after surgery
    • This outcome will be reported by physical therapy on medical records
  • Patient satisfaction with the pain management strategy provided after first 24 hours.
    • Time Frame: During the first 24 after surgery
    • patient satisfaction survey will be answered by the patient at 24 hours after surgery. This questionnaire will have a score of satisfaction from1-5, being 5 the maximum satisfaction experienced by the patient.
  • Local anesthetic toxicity reported in the medical records if is present.
    • Time Frame: During the first 24 after surgery
    • Local Anesthetic Toxicity is defined by symptoms such as metallic taste, tinnitus, drowsiness, after administering a dose of local anesthetics.This will be reported in the medical record and by the physician on call.t We will measure the number of participants that present these kind of symptoms if any.
  • Nausea and vomiting
    • Time Frame: During the first 24 after surgery
    • The presence or absence of nausea and vomiting, and the number of episodes during the first 24 hours after surgery.The outcome assessor will ask directly to the patient about this symptoms.we will measure the number of patients that report these symptoms.

Participating in This Clinical Trial

Inclusion Criteria

Patients between the ages of 19 and 90 years old. BMI 18-45 ASA class I-II-III Exclusion Criteria:

Simultaneous bilateral TKA. History of substance abuse. BMI >45. Patients that did not received Intrathecal anesthesia. Infection at the site of injection (either for spinal or PNB). Pregnancy. Non english speaking or inability to participate in the study. Patients with coagulopathy or With INR >1,5 the day of the surgery. Pharmacologic coagulopathy: patients on xarelto, plavix, or any kind of "Blood Thinners". Chronic steroid use: patients with consumption of steroid for more than 3 months. Chronic pain: pain for more than 3 months. Chronic opiate use : consumption of opioids for more than 3 months.

Gender Eligibility: All

Minimum Age: 19 Years

Maximum Age: 90 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Bruce Ben-David
  • Provider of Information About this Clinical Study
    • Sponsor-Investigator: Bruce Ben-David, Professor – University of Pittsburgh
  • Overall Official(s)
    • Bruce Ben-David, MD, Principal Investigator, University of Pittsburgh


Karlsen AP, Wetterslev M, Hansen SE, Hansen MS, Mathiesen O, Dahl JB. Postoperative pain treatment after total knee arthroplasty: A systematic review. PLoS One. 2017 Mar 8;12(3):e0173107. doi: 10.1371/journal.pone.0173107. eCollection 2017. Review.

Vora MU, Nicholas TA, Kassel CA, Grant SA. Adductor canal block for knee surgical procedures: review article. J Clin Anesth. 2016 Dec;35:295-303. doi: 10.1016/j.jclinane.2016.08.021. Epub 2016 Oct 11. Review.

Sankineani SR, Reddy ARC, Eachempati KK, Jangale A, Gurava Reddy AV. Comparison of adductor canal block and IPACK block (interspace between the popliteal artery and the capsule of the posterior knee) with adductor canal block alone after total knee arthroplasty: a prospective control trial on pain and knee function in immediate postoperative period. Eur J Orthop Surg Traumatol. 2018 Oct;28(7):1391-1395. doi: 10.1007/s00590-018-2218-7. Epub 2018 May 2.

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.