Skip to main content
SpringerLink
Log in

Infiltration Between the Popliteal Artery and Capsule of the Knee (iPACK): Essential Anatomy, Technique, and Literature Review

  • Regional Anesthesia (P Kukreja, Section Editor)
  • Published:
Current Anesthesiology Reports Aims and scope Submit manuscript

Abstract

Purpose of Review

In this review, we discuss the essential iPACK (Infiltration between the Popliteal Artery and Capsule of the Knee) anatomy, block technique as well as potential complications, contraindications, and relevant literature evaluating the efficacy of the iPACK block.

Recent Findings

Recent literature supports the efficacy of the iPACK in controlling pain, improving postoperative physical therapy performance, and decreasing hospital length of stay (LOS). Cadaver studies have demonstrated that injection of dye in the tissue plane between the popliteal artery and the femoral shaft cranial to femoral condyles spreads to the genicular nerves that innervate the posterior knee and forms the basis of the analgesic mechanism of the iPACK. Randomized controlled trials have shown that the iPACK, when used in combination with a femoral nerve block (FNB) or adductor canal block (ACB), is superior to a FNB or ACB alone in controlling postoperative pain.

Summary

The iPACK controls posterior knee pain following total knee arthroplasty (TKA) by anesthetizing the articular branches from the sciatic and obturator nerves. This is a safe and relatively simple block to perform with a low risk of serious complications.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

References

Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

  1. Sinha S, Abrams J, Sivasenthil S, Freitas D, D’Allesio J, Barnett J, Weller R, Lewis C. Use of ultrasound guided popliteal fossa infiltration to control pain after total knee arthroplasty: a prospective, randomized, observer-blinded study [Abstract P 52]. Presented at: American Society of Regional Anesthesia Meeting; March 15-18 2012; San Diego, CA.

  2. •• Terkawi AS, Mavridis D, Sessler DI, Nunemaker MS, Doais KS, Terkawi RS, et al. Pain management modalities after total knee arthroplasty: a network meta-analysis of 170 randomized controlled trials. Anesthesiology. 2017;126(5):923–37 Meta-analysis of analgesic techniques for TKA where the authors compared the efficacy of various peripheral nerve blocks and epidural analgesia, analyzing differences in pain scores, opioid consumption, and range of motion.

    Article  CAS  Google Scholar 

  3. Kukreja P, Feinstein J, Kalagara HK, Huntley SR, Lee SR, Naranje S, et al. A summary of the anatomy and current regional anesthesia practices for postoperative pain management in total knee arthroplasty. Cureus. 2018;10(6):e2755. https://doi.org/10.7759/cureus.2755.

    Article  PubMed  PubMed Central  Google Scholar 

  4. • Runge C, Moriggl B, Borglum J, Bendtsen TF. The spread of ultrasound-guided injectate from the adductor canal to the genicular branch of the posterior obturator nerve and the popliteal plexus: a cadaveric study. Reg Anesth Pain Med. 2017;42:725–30. https://doi.org/10.1097/AAP.0000000000000675A cadaveric study demonstrating the anatomic communication between the adductor canal and popliteal fossa.

    Article  PubMed  Google Scholar 

  5. Horner G, Dellon AL. Innervation of the human knee joint and implications for surgery. Clin Orthop Relat Res. 1994;301:221–6.

    Google Scholar 

  6. Gardner E. The innervation of the knee joint. Anat Rec. 1948;101:109–30.

    Article  CAS  Google Scholar 

  7. • Burkett-St. Laurant D, Peng P, Giron Arango L, Niazi AU, Chan V, Agur A, et al. The nerve of the adductor canal and the innervation of the knee: an anatomic study. Reg Anesth Pain Med. 2016;41:321–7. https://doi.org/10.1097/AAP.0000000000000389A cadaveric study identifying the innervation of posteromedial knee.

    Article  Google Scholar 

  8. •• Sinha SK. How I do it: Infiltration between Popliteal Artery and Capsule of the Knee (iPACK). ASRA newsletter; February 2019. https://www.asra.com/asra-news/article/158/how-i-do-it-infiltration-between-popliteDescriptive review of the relevant iPACK anatomy and procedural technique by the inventor of the iPACK, Dr Sanjay Sinha

  9. •• Niesen AD, Harris DJ, Johnson CS, Stoike DE, Smith HM, Jacob AK, et al. Interspace between Popliteal Artery and posterior Capsule of the Knee (IPACK) injectate spread: a cadaver study. J Ultrasound Med. 2018;00:1–5. https://doi.org/10.1002/jum.14761A cadaveric study examining the spread of colored latex during iPACK injections, suggesting a possible mechanism for the analgesic effect of this block. The potential for local anesthetic spread to the tibial and common peroneal nerves is also highlighted.

    Article  CAS  Google Scholar 

  10. Frank H. Netter. Atlas of human anatomy. 3rd Edn. ICON Learning Systems 2003.

  11. •• Tran J, Giron AL, Peng P, Sinha SK, Agur A, Chan V. Evaluation of the iPACK block injectate spread: a cadaveric study. Reg Anesth Pain Med. 2019;44:689–94. https://doi.org/10.1136/rapm-2018-100355A cadaveric study examining the spread of methylene blue–colored water following distal and proximal iPACK injection techniques. This study describes the different articular branches that are most likely contributing to the analgesic effect of the iPACK block.

    Article  Google Scholar 

  12. Thobhani S, Scalercio L, Elliott CE, Nossaman BD, Thomas LC, Yuratich D, et al. Novel regional techniques for total knee arthroplasty promote reduced hospital length of stay: an analysis of 106 patients. Ochsner J. 2017;17(3):233–8.

    PubMed  PubMed Central  Google Scholar 

  13. •• 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;28(7):1391–5. https://doi.org/10.1007/s00590-018-2218-7This prospective study compares pain scores between two cohorts of patients undergoing unilateral TKA. The authors found significantly lower pain scores in the combination group of adductor canal block (ACB) + iPACK when compared with adductor canal block alone.

    Article  CAS  PubMed  Google Scholar 

  14. •• Kim DH, Beathe JC, Lin Y, YaDeau JT, Maalouf DB, Goytizolo E, et al. Addition of infiltration between the popliteal artery and the capsule of the posterior knee and adductor canal block to periarticular injection enhances postoperative pain control in total knee arthroplasty: a randomized controlled trial. Anesth Analg. 2018. https://doi.org/10.1213/ANE.0000000000003794This randomized controlled trial compares postoperative pain scores between patients receiving either periarticular injection alone or periarticular injection in combination with adductor canal block and iPACK injection. The authors found significantly lower pain scores and opioid consumption in the study group of periarticular injection + ACB + iPACK.

Download references

Author information

Authors and Affiliations

  1. Department of Anesthesiology, St. Francis Hospital and Medical Center, 114 Woodland Street, Hartford, CT, 06105, USA

    Sanjay K. Sinha, Alexa Clement & Ann-Marie Surette

Authors
  1. Sanjay K. Sinha
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Alexa Clement
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ann-Marie Surette
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Sanjay K. Sinha.

Ethics declarations

Conflict of Interest

Sanjay K. Sinha has received compensation from Pacira Pharmaceuticals for contributing to speaker’s bureaus and from Flexion Therapeutics for service as a consultant.

Alexa Clement declares that she has no conflict of interest.

Ann-Marie Surette declares that she has no conflict of interest.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

This article is part of the Topical Collection on Regional Anesthesia

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sinha, S.K., Clement, A. & Surette, AM. Infiltration Between the Popliteal Artery and Capsule of the Knee (iPACK): Essential Anatomy, Technique, and Literature Review. Curr Anesthesiol Rep 9, 474–478 (2019). https://doi.org/10.1007/s40140-019-00358-5

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40140-019-00358-5

Keywords

Search

Navigation