Method for treating neuropathic, orthopedic and phantom pain syndromes

Abstract

FIELD: neurology; neurosurgery; traumatology; orthopedics.SUBSTANCE: used to treat neuropathic, orthopedic and phantom pain syndromes. The method involves radiofrequency ablation of nerve endings. In this case, damaged nerve endings are identified using radiation and ultrasound diagnostic methods. Then, test low-voltage stimulation of the selected nerves and peripheral anesthesia of the selected area are performed. At the same time, radiofrequency ablation is performed in monopolar mode according to specified parameters.EFFECT: method allows for a lasting pain relief effect in neuropathic, orthopedic and phantom pain.1 cl, 12 dwg, 5 ex

Description

[0001] The invention relates to medicine, namely to neurology, neurosurgery, traumatology-orthopedics, and can be used to treat neuropathic, orthopedic and phantom pain syndromes.

[0002] Neuropathic and phantom pain are serious problems associated with nerve damage, compression, amputation, neuroma formation, or nerve involvement in scar tissue. Various approaches and techniques are used to address this problem. These include conservative therapy, surgical interventions (resection of a large nerve stump, sympathectomy, thalamic surgery, neurolysis, etc.), and physical therapy (electrical and / or magnetic stimulation of various structures of the peripheral or central nervous system).

[0003] Traditional methods such as decompression, neurotomy, and reamputation can be ineffective and are associated with recurrence of pain, prolonged recovery periods, and significant financial costs for the patient. There is a need for minimally invasive, targeted treatments that reduce pain and promote earlier and more effective recovery.

[0004] A traditional method of complex drug treatment of phantom and neuropathic pain is known (Chegurov OK et al., Phantom Pain Syndrome: Pathogenesis, Treatment, Prevention, Genius of Orthopedics, No. 1, 2014, pp. 90-92), which includes the use of non-narcotic and narcotic analgesics (ketamine, morphine, tramadol), the use of non-steroidal anti-inflammatory drugs, anticonvulsants (carbamazepine, gabapentin, etc.), antidepressants, such as amitriptyline. For the treatment of phantom and neuropathic pain, antipsychotics (haloperidol, etc.) can be used to reduce psychotic activity, sedative effect and enhance the effect of analgesics, anticonvulsants and antidepressants. The disadvantage of such complex treatment for phantom and neuropathic pain is the long-term use of drugs that can cause side effects.Overall, treatment results, even at maximum dosages, may be ineffective, creating a situation where the risks of drug use outweigh the therapeutic benefits. There are risks of drug dependence, gastrointestinal bleeding, cardiotoxicity, cardiac arrhythmia, hypotension, respiratory distress, extrapyramidal disorders, seizures, and decreased consciousness.

[0005] For example, a method for treating pain after limb amputation is known (patent RU 2823155 C1, published 18.07.2024), which includes the introduction of botulinum toxin type A into the stump. Botulinum toxin type A is administered subcutaneously, with injections made around the surgical scar at a distance of 0.5-1.0 cm from it and with an interval of 1-2 cm between injections, then injections are made over the entire area of ​​​​the stump with an interval of 1-2 cm between them, while the dose per injection in the presence of a neuropathic pain zone of the stump is 4-5 U, and without pain - 2-3 BD of the drug, up to a total dose of 100-150 U for the upper limb and 210-250 U for the lower limb. However, this method has the following disadvantages:

[0006] - The need to cover a larger area of ​​exposure to the toxin;

[0007] - Accurate selection of drug dosage;

[0008] - Damage to other structures that are not the innervation zone;

[0009] - Temporary effect.

[0010] A method of radiofrequency denervation for chronic pain syndrome by heating the electrode above 82°C is described in the literature (see Sidorovich PP et al., Neurosurgical treatment of patients with constant intractable pain in post-traumatic mono- and polyneuropathies using radiofrequency ablation, Advances in modern clinical neurology and neurosurgery: Collection of materials from the XVIII Republican scientific and practical conference with international participation for young specialists, Grodno, May 17, 2019, pp. 80-82). With this method, a neuroma was punctured with a 1 mm diameter, 150 mm long needle covered with insulating material on the outside with a cannula. Under ultrasound guidance, the end of the needle was inserted into the neuroma. The cannula was removed and an electrode connected to a neurogenerator was inserted into the needle. The end of the electrode protruded 1 mm beyond the needle.Neurophysiological testing was then conducted: a 100 Hz pulse was applied to the electrode, causing pain upon insertion into the nerve tissue. If the test result was positive and the electrode was confirmed to be inserted into the neuroma, high-frequency thermal destruction of the neuroma was performed at 90 degrees Celsius for 90 seconds. The destruction zone was no more than 7 mm in diameter. For neuromas larger than 7 mm, the needle tip position was adjusted under ultrasound and neurophysiological guidance. If the neurophysiological stimulation responded positively, thermal destruction was repeated. After cooling, the electrode and needle were removed. This method also has some disadvantages:

[0011] - Small area of ​​destruction, which does not allow the method to be used on large nerve structures;

[0012] - The method requires expert knowledge of radiation and ultrasound diagnostic methods;

[0013] - Relapse of pain syndrome due to preservation of the pathway of nerve communication with the neuroma;

[0014] - During ablation, an area of ​​coagulation necrosis is created; ablation of the neuroma area will lead to constant irritation and trauma from the prosthesis sleeve, and given the close location to the surface of the end part of the stump, it can burn through the subcutaneous fat or even the skin, exposing the neuroma.

[0015] Also, the prior art knows a method for treating phantom pain in the lower limb (patent RU 2817812 C1, published 04 / 22 / 2024), which we have chosen as a prototype and includes identifying the sciatic nerve by means of ultrasound scanning with a linear-type sensor with an operating frequency of 4-12 MHz above the damaged area, then anesthetizing the skin, after which two electrodes sequentially carry out sensory and motor test stimulation by applying a pulse with a frequency of 50 Hz and a pulse with a frequency of 2 Hz to the electrode, respectively, if the result of both test parameters is positive, bipolar pulsed radiofrequency ablation of the nerve (PRF) is performed with two electrodes heated to 42 ° C, with an electric current voltage of 45 V and a pulse frequency of 2 Hz, for 4 minutes, after performing PRF, 4 ml of a 1% lidocaine solution and 4 mg are administered Dexamethasone is administered perineurally, and the electrodes are removed and an aseptic dressing is applied. This method has the following disadvantages:

[0016] - When performing bipolar neuromodulation, only a temporary decrease in the activity of nerve impulses occurs due to the discharge of the membrane, which leads to a temporary analgesic effect, in addition, the area of ​​​​impact is limited to the area between the electrodes, thereby capturing only a straight line of the path of least resistance between the electrodes, which does not provide a clear understanding of how much of the nerve is covered by this intervention, whether it is expressed to a sufficient extent;

[0017] - The following disadvantage follows from the above - small coverage of the area of ​​action, which does not make it possible to use the method on large nerve structures;

[0018] - The need for simultaneous installation of two electrodes to the nerve (comparison of three linear structures in one projection) requires expert knowledge of radiation and ultrasound diagnostic methods;

[0019] - Impairment of motor function below the level of impact due to mixed structure of the sciatic nerve;

[0020] Therefore, there is a need for a method for treating neuropathic, orthopedic and phantom pain syndromes that is free from the above-mentioned disadvantages.

[0021] The technical result of the proposed method is increased treatment effectiveness for neuropathic, orthopedic, and phantom pain syndromes by destroying the pain pathway using optimally selected parameters of monopolar radiofrequency ablation, selectively targeting damaged nerves under ultrasound or fluoroscopy guidance. The pain-relieving effect is highly persistent.

[0022] To achieve the specified technical result in the method for treating neuropathic, orthopedic and phantom pain syndromes, including radiofrequency ablation of nerve endings, it is proposed to identify damaged nerve endings using radiation diagnostic methods, conduct test low-voltage stimulation of selected nerves, and peripheral anesthesia of the selected area, while radiofrequency ablation is carried out in a monopolar mode with the following parameters: temperature 70-90°C, time 60-600 seconds, electrical voltage 10-150 V, power 5-50W.

[0023] Fig. 1-12 illustrate the following clinical examples.

[0024] The method is carried out as follows.

[0025] Patients with chronic neuropathic, phantom, or orthopedic pain are examined to determine the etiology: to confirm the presence of a neuroma, nerve compression, or scarring in the nerve area, or an orthopedic cause. Target nerves are identified using ultrasound or fluoroscopy landmarks. A radiofrequency needle electrode is inserted into the area above the neuroma, compression, or scar, or the pain distribution zone. Low-voltage sensory stimulation is administered to confirm the target area or to compare clinical symptoms with the anatomy of the pathological process. Motor stimulation is performed to rule out damage to motor nerve fibers. A local anesthetic is administered to numb the nerve and create a fluid environment that increases the target area.Pulsed or continuous radiofrequency ablation is performed (temperature 70-90°C, time 60-600 seconds, voltage 10-150 V, power 5-50 W). For this purpose, we used the Cosman G4 radiofrequency generator, but other coagulation devices can also be used. Increasing the time, voltage, temperature, and power within the specified range depends on the nerve caliber and increases the treatment area. Pain reduction is confirmed by examination using a pain scale, neuropathic syndrome, clinical examination, and postoperative sensory stimulation. Post-procedure results include: persistent regression of neuropathic, phantom, orthopedic, or other pain syndromes, or a significant reduction in intensity; numbness in the innervation zone of the sensory or mixed nerve; improved prosthesis tolerance.The proposed method is targeted at the growing number of patients following amputation, trauma, or nerve damage, particularly in combat-related settings, ensuring faster recovery and improved quality of life. It reduces the need for repeat surgeries and promotes functional rehabilitation.

[0026] The high efficiency of the proposed method is confirmed by the clinical examples below.

[0027] Example 1. Patient Ch., 40 years old. Diagnosis: MVR from ***, Amputation of both hips at the level of the middle third.

[0028] Complaints at the time of examination: paroxysmal pain in the area of ​​the stump of the right thigh (VAS 7-8 points), intensifying in the morning and evening, phantom pain in both lower limbs according to VAS 3-4 points.

[0029] Therapy: Ketoprofen 100 mg intramuscularly up to 3 times a day, Gabapentin 900 mg three times a day (ineffective).

[0030] The patient completed the Oswestry Pain Detect questionnaire (26 points), which identified the pain as neuropathic. Palpation and percussion of the right femoral nerve's musculocutaneous branch also revealed positive Tinel's sign (pain).

[0031] Surgery performed: radiofrequency denervation of the musculocutaneous branch of the right femoral nerve. During the surgery:

[0032] With the patient in the prone position, after three treatments of the surgical field, an ultrasound examination of the nerves was performed: Two neuromas up to 4 mm in size were visualized in two branches of the musculocutaneous branch of the right femoral nerve. (Fig. 1, Fig. 2). Under U3 control, a needle-cannula was inserted into the musculocutaneous branch of the right femoral nerve (branches were traced) above the bifurcation into small branches. An anesthetic was injected epineurally - 2 ml of 1% Lidocaine solution. After anesthetic exposure (5 minutes), an electrode was inserted into the needle-cannula (Fig. 3), and radiofrequency denervation was performed with the following parameters: 90C°, 5-20 W, 40-60 V, for 5 minutes. Ultrasound examination revealed a nerve coagulation zone (Fig. 4). The needle and electrode are removed, aseptic dressing.

[0033] Control:

[0034] The patient maintained conduction anesthesia for 1 hour, the pain syndrome was assessed at 0 points on the VAS.

[0035] Within 24 hours, a complete absence of pain was noted in the projection of the innervation zone of the cutaneous-muscular branch, numbness in the area of ​​innervation, pain at the site of skin puncture VAS 2 points.

[0036] Within 7 days after surgery: Analgesic therapy was discontinued. Numbness persists, VAS score 0.

[0037] After 1 month - Numbness persists, YOUR score is 0, a custom-made prosthesis was made.

[0038] After 3 months - Numbness persists, YOUR score is 0 points, the patient is fully adapted to the individual exoprosthesis.

[0039] Example 2. Patient L., 48 years old. Diagnosis: Blast wound on April 22, 2025. Incompetent lower limb stump at the level of the middle third of the lower leg on the right (painful neuromas of the sural nerve) due to a gunshot blind shrapnel wound to the soft tissues of the right lower limb with destruction of the foot. Operations: Amputation of the right lower limb at the level of the lower third of the lower leg on April 26, 2025. Reamputation of the right lower limb at the level of the middle third of the lower leg, stump formation on April 28, 2025.

[0040] Complaints at the time of examination: Nagging pain in the stump at rest (VAS 4 points), increasing with axial load on the stump (VAS 8-9 points), limiting the manufacture of a prosthesis, phantom pain from the end of the stump to the heel (VAS 2-5 points depending on the time of day).

[0041] Therapy: Ketoprofen 100 mg intramuscularly up to 3 times a day, Gabapentin 600 mg 3 times a day (ineffective).

[0042] Palpation and percussion of the end surface in the projection of the anatomical location of the sural or tibial nerves reveals a positive Tinel's sign, characterized by shooting pain in the popliteal region and the development of phantom heel pain (sural nerve). Pain is also felt on the outer surface of the stump along the edge of the fibula. Percussion reveals pain radiating from the outer surface to the lateral part of the popliteal region.

[0043] Surgery performed: radiofrequency denervation of the right sural and common peroneal nerves. During the surgery:

[0044] With the patient in the prone position, under conduction anesthesia of the right sciatic nerve at the level of the upper third of the thigh with a solution diluted with 0.9% NaCl to 20 ml (Ropivacaine - 10 ml 1%, Dexamethasone - 2 ml 4 mg / ml), after three times processing the surgical field, an ultrasound examination of the nerves was performed: 2 neuromas were visualized: Terminal neuroma of the sural nerve measuring 0.5 cm in duplication at the end of the stump (Fig. 5), neuroma of the superficial branch of the peroneal nerve. Under U3 control, the needle-cannula was alternately passed to the sural nerve in the area of ​​​​the upper third of the leg, 3 ml was injected. A 1% ropivacaine solution was applied, an electrode was inserted into the needle-cannula, and radiofrequency denervation was performed using the following parameters: 90°C, 5-20 W, 40-60 V, for 5 minutes. Ultrasound examination revealed the zone of nerve coagulation (Fig. 6).A needle-cannula was inserted into the common peroneal nerve at the popliteal fossa, 3 ml of 1% ropivacaine solution was injected, an electrode was inserted into the needle-cannula, and radiofrequency denervation was performed using the following parameters: 90°C, 5-20 W, 40-60 V, for 5 minutes. The needle and electrode were removed, and an aseptic dressing was applied.

[0045] Control:

[0046] The patient maintained conduction anesthesia for 1 hour, the pain syndrome was assessed at 0 points on the VAS.

[0047] Within 24 hours, a complete absence of neuropathic pain syndrome was noted (VAS 0 points), phantom pain syndrome changed from sharp electric-like pain to tingling (paresthesia VAS 1-2 points), sensitivity in the stump was restored with the exception of the outer surface of the leg (projection of the innervation of the peroneal nerve)

[0048] Within 7 days after surgery: Analgesic therapy was discontinued. Anesthesia in the peroneal nerve projection was maintained. Phantom pain syndrome was experienced three times over the past 7 days (VAS 2-3 points). Palpation was painless. The patient was transferred to the exoprosthetic area.

[0049] Example 3. Patient G., 23 years old. Diagnosis: Blast wound from April 19, 2025. Traumatic avulsion of the right foot. Amputation stump of the middle third of the right leg.

[0050] Complaints at the time of examination: sharp, shooting pain along the outer and inner surfaces of the shin stump (VAS 7-8 points), phantom pain syndrome, manifested by pain in the projection of the outer surface of the shin, the end surface of the foot (VAS 6 points)

[0051] Therapy: Ketoprofen 100 mg intramuscularly up to 3 times a day, Gabapentin 600 mg 3 times a day (ineffective).

[0052] Palpation and percussion of the outer surface of the stump along the edge of the fibula reveal a positive Tinel's sign radiating to the lateral popliteal region. Palpation and percussion of the inner surface of the stump near the scar reveal a sharp pain syndrome radiating along the inner surface of the leg, as well as to the medial aspect of the knee joint (innervation zone of the saphenous nerve).

[0053] Surgery performed: radiofrequency denervation of the right saphenous and common peroneal nerves. During the surgery:

[0054] With the patient in the prone position, under conduction anesthesia of the right sciatic nerve at the level of the upper third of the thigh with a solution diluted with 0.9% NaCl to 20 ml. (Ropivacaine - 10 ml. 1%, Dexamethasone - 2 ml 4 mg / ml.), after three times processing of the surgical field, an ultrasound examination of the nerves was performed: A terminal neuroma of 0.7 mm. of the superficial branch of the peroneal nerve was visualized (Fig. 7), as well as a small bull-shaped thickening in the projection of the saphenous nerve (near the great saphenous vein). Under U3 control, the needle-cannula was alternately advanced to the saphenous nerve at the level of the knee joint (visualization is difficult due to the size of the nerve). An electrode was inserted into the cannula, and test sensory stimulation was performed - paresthesia was obtained in the area of ​​innervation of the saphenous nerve at 0.6 V. The needle-cannula was displaced until paresthesia was obtained at a sensory stimulation value of up to 0.2 V (in this case - 0.16V), 3 ml of 1% Ropivacaine solution was injected into the cannula, the anesthetic exposure was performed for 5 minutes, an electrode was placed in the needle-cannula, and radiofrequency denervation was performed with the following parameters: 90C°, 5-20 W, 40-60 V, for 5 minutes. The needle-cannula was inserted into the lumen of the common peroneal nerve at the level of the popliteal fossa, 3 ml of 1% Ropivacaine solution was injected, an electrode was placed in the needle-cannula, and radiofrequency denervation was performed with the following parameters: 90C°, 5-20 W, 40-60 V, for 5 minutes. Ultrasound examination revealed the nerve coagulation zone (Fig. 8). The needle and electrode were removed, and an aseptic dressing was applied.

[0055] Control:

[0056] The patient maintained conduction anesthesia for 1 hour, the pain syndrome was assessed at 0 points on the VAS.

[0057] Within 24 hours, a complete absence of neuropathic pain syndrome was noted (VAS 0 points), phantom pain syndrome did not appear (VAS 0 points), sensitivity in the right lower limb was restored with the exception of the outer surface of the shin (projection of the innervation of the peroneal nerve), the anterior-inner surface of the shin (projection of the innervation of the subcutaneous nerve), pain syndrome at the puncture sites (VAS 2-3 points) of a pulling nature was noted, as well as slight pastosity of the stump.

[0058] Within 7 days after surgery: Analgesic therapy was discontinued. Swelling has regressed, and the puncture sites are painless. Anesthesia in the peroneal nerve projection is maintained, no phantom or pain syndrome occurred (VAS score 0), palpation is painless, and the patient is transferred to the exoprosthetic area.

[0059] Case 4. Patient K., 23 years old. Diagnosis: Combined blast injury from 10.04.2025. Positional compression syndrome of the left lower limb. Shrapnel wound of the left hand, both lower limbs. Post-traumatic neuropathy of the ulnar nerve on the left. Gunshot comminuted fracture of the base of the proximal phalanx of the 5th finger of the left bone with displacement of fragments. Multiple wounds of the left hand. Foreign bodies (Me+) of the soft tissues of the left hand. Gunshot perforated fracture of the upper third of the left tibia with the presence of a foreign body (Me+) in the fracture area; gunshot comminuted fracture of the anterior edge of the distal metaepiphysis of the left tibia; marginal fracture of a fragment of the medial condyle of the left tibia; Gunshot fracture of the lateral malleolus with a marginal bone defect. Multiple gunshot wounds to the left thigh, left leg, and left foot.

[0060] Complaints at the time of examination: Pain in the left knee joint at rest (VAS 3-5 points), increasing with movement (VAS 6-7 points).

[0061] Movements in the left knee joint in extreme positions cause pain. "Drawer" symptoms (negative), signs of gonarthrosis according to CT data: uneven joint space, foreign bodies of Me+ density (Fig. 9).

[0062] Surgical intervention performed: radiofrequency denervation of the left knee joint

[0063] With the patient in the prone position and under combined anesthesia, the surgical field is prepared three times. Under image intensifier control, needle-cannulas are inserted one by one into the lumen of the superior-medial femoral, superior-lateral femoral, and inferior-medial tibial geniculate nerves (Fig. 10). 3-4 ml of 1% ropivocaine solution is injected into the cannula. Electrodes are inserted and radiofrequency denervation is performed one by one with the following parameters: 85C, 45V, 18.0W, 600 sec. The needle and electrode are removed and an aseptic dressing is applied. Control:

[0064] The patient maintained local anesthesia for 1 hour, the pain syndrome was assessed at 0 points on the VAS.

[0065] Within 1 day after the operation, the patient noted a decrease in the intensity of pain in the knee joint according to the VAS to 1-2 points during physical activity, mainly in the area of ​​the puncture sites.

[0066] Within 7 days after surgery: analgesic therapy was discontinued. The puncture sites are painless. Complete regression of pain was noted (VAS score 0), including pain during stress testing. The patient also subjectively reports a "cold knee."

[0067] Example 5. Patient F., 49 years old. Diagnosis:

[0068] Main diagnosis: Combined wound of the abdomen, pelvic bones, and extremities from 05 / 07 / 2023: shrapnel blind wound penetrating wound of the abdomen with damage to the small intestine and a defect in the soft tissues of the anterior abdominal wall, shrapnel blind wound of the pelvic bones with a comminuted fracture of the ilium and right lateral masses of the sacrum, blind shrapnel wounds of the soft tissues of the left shoulder, gluteal region, fracture of the 12th rib on the right. Giant postoperative median ventral hernia of the anterior abdominal wall. Surgery from 03 / 12 / 2025 - Hernioplasty of postoperative ventral hernia with local tissues.

[0069] Associated diseases: M17.9 Medial gonarthrosis of the right knee joint.

[0070] Complaints at the time of examination: intermittent pain in the lower abdomen, numbness of the toes of the right foot. Pain in the right knee joint at rest (VAS 2-3 points), increasing with movement (VAS 6-7 points). Movement of the right knee joint in extreme positions causes pain. Drawer signs are negative, signs of gonarthrosis according to MRI data from April 18, 2025: uneven joint space, osteophytes (Fig. 11).

[0071] Surgical intervention was performed: radiofrequency denervation of the right knee joint.

[0072] With the patient in the supine position and under local anesthesia, 10 ml of 1% ropivocaine solution was applied to the needle entry sites in the area of ​​the right knee joint using image intensifier navigation. After treating the surgical field with an antiseptic solution for the right shin, the electrode was placed on the medial reticular nerve, the superomedial femoral nerve, and the inferomedial femoral nerve one by one under image intensifier control (note: Fig. 12). 2 ml of ropivocaine solution was injected into the cannula. Radiofrequency denervation was performed one by one using the following parameters: 80C, 45V, 18.0W, 600s. The electrodes were removed and an aseptic dressing was applied.

[0073] Control:

[0074] The patient maintained local anesthesia for 1 hour, the pain syndrome was assessed at 0 points on the VAS.

[0075] Within 1 day after the operation, the patient noted a decrease in the intensity of pain in the knee joint according to the VAS to 1-2 points during physical activity, mainly in the area of ​​the puncture sites.

[0076] Within 7 days after surgery: analgesic therapy was discontinued. Puncture sites are painless. Complete regression of pain was noted (VAS score 0).

Claims

A method for treating neuropathic, orthopedic and phantom pain syndromes, including radiofrequency ablation of nerve endings, characterized in that damaged nerve endings are identified using radiation and ultrasound diagnostic methods, test low-voltage stimulation of selected nerves is performed, peripheral anesthesia of the selected area is performed, while radiofrequency ablation is carried out in a monopolar mode with the following parameters: temperature 70-90°C, time 60-600 seconds, electrical voltage 10-150 V, power 5-50 W.

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