Surgeon-performed pericapsular nerve group (PENG) block for total hip arthroplasty using the direct anterior approach: a cadaveric study

Abstract

BackgroundDuring total hip arthroplasty (THA) using the direct anterior approach, orthopaedic surgeons can identify all anatomical landmarks required for pericapsular nerve group (PENG) blocks and carry out the latter under direct vision. This cadaveric study investigated the success of surgeon-performed PENG block. Success was defined as dye staining of the articular branches of the femoral and accessory obturator nerves.Methods11 cadavers (18 hip specimens) were included in the current study. To simulate THA in live patients, an orthopaedic surgeon inserted trial prostheses using the direct anterior approach. Subsequently, a block needle was advanced until contact with the bone (between the anterior inferior iliac spine and iliopubic eminence). 20 mL of 0.1% methylene blue was injected. Cadavers were then dissected to document the presence and dye staining of the femoral, lateral femoral cutaneous, obturator and accessory obturator nerves as well as the articular branches of the femoral, obturator and accessory obturator nerves.ResultsMethylene blue stained the articular branches of the femoral nerve and the articular branches of the accessory obturator nerve (when present) in all hip specimens. Therefore, surgical PENG block achieved a 100% success rate. Dye stained the femoral and obturator nerve in one (5.6%) and two (11.1%) hip specimens, respectively. No dye staining was observed over the accessory obturator nerve in the pelvis nor the lateral femoral cutaneous nerve.ConclusionSurgeon-performed PENG block during direct anterior THA reliably targets the articular branches of the femoral and accessory obturator nerves. Future trials are required to compare surgeon-performed PENG block with anaesthesiologist-performed, ultrasound-guided PENG block, and surgeon-performed periarticular local anaesthetic infiltration.

Pericapsular Nerve Group Block and Iliopsoas Plane Block: A Scoping Review of Quadriceps Weakness after Two Proclaimed Motor-Sparing Hip Blocks

“…More importantly, if PENG block does frequently end up as an iliopectineal bursa injection with potential bursal rupture/puncture, the injectate can then manage to breach the medial border of IP (formed by IT and its closely associated iliopectineal bursa) and subsequently spread anteromedially along the surface of PM to catch the femoral nerve proper within FIC, causing quadriceps weakness. In support of our speculation, a recently published surgeon-performed PENG block cadaver study showed that femoral nerve proper and obturator nerve divisions were stained in 5.6% and 11.1% of their specimen, and abundant dye could again be seen spreading along the undersurface of IT (corresponding to iliopectineal bursa) and further extended anteromedially to involve femoral nerve proper and posteromedially to obturator nerves (extrapelvic) [ 39 ].…”

“…Finally, we found 5 cadaveric dye injection studies and 32 clinical studies to be included in our review ( Figure 3 ). Among the cadaveric studies, there are four articles on PENG block [ 22 , 37 , 38 , 39 ] and one on IPB [ 8 ]. All clinical studies except one randomized controlled trial (RCT) [ 7 ] and two recently published case series [ 40 , 41 ] utilized PENG block.…”

“…Since Iliopectineal bursa lies immediately deep to iliopsoas tendon (IT), it can be easily injected during PENG block. As the bursa ruptures from pressure/volume overload or is punctured by the needle tip, both the anteromedial spread along the anterior surface of psoas major (PM) to involve femoral nerve proper and the posteromedial spread to involve either the obturator nerve proper (intrapelvic) or its divisions (extrapelvic) can occur [ 22 , 39 ]. When iliopectineal bursa is injected, intra-articular spread via the bursal-synovium communication can also occur [ 38 ].…”

Anatomical and Radiological Assessments of Injectate Spread Stratified by the Volume of the Pericapsular Nerve Group Block

“…Previously, Kitcharanant et al 28 conducted a cadaveric assessment of dye spread pattern after surgeon-performed PENG block for THA using the direct anterior approach. The PENG block was performed by injecting 20 mL of 0.1% methylene blue after inserting a needle lateral to the psoas tendon with direct visualization by the orthopedic surgeon.…”

“…26 Some authors have expressed concern high local anesthetic volume may lead to anesthetic spread to the FN, causing inadvertent quadriceps weakness. 20,24,27 Previously, Kitcharanant et al 28 conducted a cadaveric assessment of dye spread pattern after surgeonperformed PENG block with 0.1% of methylene blue for THA using the direct anterior approach. However, to our knowledge, there are only a few cadaveric and radiological studies related to injectate spread during implementation stratified by different volumes and performed by anesthesiologists.…”