PMC9173899_01
Nerve to vastus intermedius (NVI) denervation (either the medial or the lateral branches). (a) The transverse view shows the needle inserted in an in-plane approach to the midfemoral shaft. (b) The coronal view shows the Doppler signal that signifies superomedial or superolateral genicular artery at the junction of femoral shaft and femoral epicondyle. White arrow: needle; asterisk: the needle target. (c) A lateral view of fluoroscope of the knee with needle placement for NVI (either the medial or the lateral branches) denervation as shown at 1.
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fig1
A supplementary coronal view allowed checking of the position of the needle tip close to the nerve and the vessel (Figure 1). It covered the lateral branches of NVI (Figure 1).
(a) Denervation of the infrapatellar branch of the saphenous nerve (IPBSN) posterior to adductor tubercle. (b) Denervation of superomedial genicular nerve (SMGN) anterior to adductor tubercle. Note the Doppler signals that signify the vessels accompanying the nerves. AT: adductor tubercle; white arrow: Nimbus  radiofrequency needle. (c) A lateral view of fluoroscope of the knee with needle placement for SMGN (more anterior) and IPBSN (more posterior) denervation as shown at 2.
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fig2
This was often accompanied by the saphenous branch of descending genicular artery (Figure 2).
Superolateral genicular nerve denervation. (a) An axial view to identify the posterior edge of the lateral femoral cortex manifested as an edge separating the lateral side and the posterior side of the cortex. (b) An oblique view at around 45 degrees from the coronal plane shows the femoral shaft. LFC: lateral femoral condyle; white arrow: the proposed needle trajectory toward the target point; asterisk: the final needle tip position when scanning from the oblique coronal plane to the axial plane.
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fig3
This was the target of the true SLGN (Figure 3).
Inferomedial genicular nerve (IMGN) denervation. (a) A coronal view shows that the IMGN and its accompanying inferomedial genicular artery are located underneath the medial collateral ligament with the needle tip shown. (b) A transverse view shows that the needle is inserted in-plane to the midshaft of the tibia. Solid white arrow: needle; hollow white arrow: medial collateral ligament. (c) A lateral view of fluoroscope of the knee with needle placement for IMGN denervation as shown at 3.
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fig4
A supplementary coronal view allowed checking of the needle tip beneath the medial collateral ligament, close to the nerve and the vessel (Figure 4).
Popliteal nerve plexus neurolysis. (a) An ultrasound-guided lateral-to-medial needle trajectory underneath the biceps femoris, gastrocnemius, and plantaris. The final needle position targets at the intercondylar bony surface. BF: biceps femoris; G: lateral head of gastrocnemius; P: plantaris; LFC: lateral femoral condyle; MFC: medial femoral condyle; A: popliteal artery; bold white arrow: needle; thin arrow: needle trajectory. (b) The anteroposterior and the lateral views of the needle placement for the popliteal nerve plexus neurolysis.
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fig5
If the chemical approach was adopted, the needle trajectory was modified such that the needle advancement was maintained underneath the lateral head of gastrocnemius and plantaris while the final needle position was the same (Figure 5).