The rostral agranular insular cortex (RAIC) has been associated with pain modulation. Although the endogenous cannabinoid system (eCB) has been shown to regulate chronic pain, the roles of eCBs in the RAIC remain elusive under the neuropathic pain state. Neuropathic pain was induced in C57BL/6 mice by common peroneal nerve (CPN) ligation. The roles of the eCB were tested in the RAIC of ligated CPN C57BL/6J mice, glutamatergic, or GABAergic neuron cannabinoid receptor 1 (CB1R) knockdown mice with the whole-cell patch-clamp and pain behavioral methods. The E/I ratio (amplitude ratio between mEPSCs and mIPSCs) was significantly increased in layer V pyramidal neurons of the RAIC in CPN-ligated mice. Depolarization-induced suppression of inhibition but not depolarization-induced suppression of excitation in RAIC layer V pyramidal neurons were significantly increased in CPN-ligated mice. The analgesic effect of ACEA (a CB1R agonist) was alleviated along with bilateral dorsolateral funiculus lesions, with the administration of AM251 (a CB1R antagonist), and in CB1R knockdown mice in GABAergic neurons, but not glutamatergic neurons of the RAIC. Our results suggest that CB1R activation reinforces the function of the descending pain inhibitory pathway via reducing the inhibition of glutamatergic layer V neurons by GABAergic neurons in the RAIC to induce an analgesic effect in neuropathic pain.
Mice ; Animals ; Insular Cortex ; Peroneal Nerve ; Mice, Inbred C57BL ; Neuralgia ; GABAergic Neurons ; Analgesia ; Analgesics ; Receptors, Cannabinoid

OBJECTIVE: To analyze the incidence and characteristics of fabella in the Chinese population and its correlation with pain in the posterolateral region of the knee joint and common peroneal nerve palsy. METHODS: Total 732 patients including 405 males(450 knees) and 327 females(383 knees) who underwent unilateral or bilateral knee MR imaging from September 2015 to July 2019 were retrospectively evaluated. The basic information of all patients was extracted from the hospital's his system. The patient's medical records were checked by telephone follow-up or his system, and the number of patients with posterolateral knee pain and common peroneal nerve paralysis were recorded. RESULTS: The overall prevalence of fabella was 48.38%, 23.53% in men and 24.85% in women, there was no significant difference between them ( CONCLUSION The prevalence of fabella us in Chinese population is 48.38%. There is no relationship between the incidence of gastrocnemius and gender, but the incidence of fabella is positively correlated with age, pain in the posterolateral region of the knee joint and the occurrence of common peroneal nerve symptoms.
Adult ; Female ; Humans ; Knee Joint ; Male ; Middle Aged ; Pain ; Peroneal Nerve ; Peroneal Neuropathies/epidemiology* ; Retrospective Studies ; Young Adult

Tensor fasciae suralis, also known as ischioaponeuroticus is a clinically relevant muscle variant located in the popliteal fossa. Though rare, when present the muscle may arise from any of the hamstrings and gets inserted to the crural fascia of leg or tendocalcaneus and is innervated by the tibial component of sciatic nerve. Here we report a variant of tensor fasciae suralis originated from the lowermost part of linea aspera along with the fibers of short head of biceps femoris in the left lower limb of a male cadaver aged approximately 58 years. The muscle was 16 cm in length and 1 cm breadth in its widest part. It was found inserted to the crural fascia over the lateral head of gastrocnemius and was found innervated by common peroneal nerve. To the best of our knowledge, the tensor fascia suralis muscle originated from linea aspera along with short head of biceps femoris and innervated by common peroneal nerve has not been reported in either cadaveric or imaging studies.
Cadaver ; Fascia ; Head ; Humans ; Leg ; Lower Extremity ; Male ; Peroneal Nerve ; Sciatic Nerve

BACKGROUND: This study aimed to determine the optimal location of local anesthetic injection in the interspace between the popliteal artery and posterior capsule of the knee (iPACK), using the anatomical pattern of the articular branch of tibial nerve (ABTN). We hypothesized that injection at the level of ABTN forming a popliteal plexus would mainly spread throughout the popliteal fossa without contacting the tibial or peroneal nerves. METHODS: The anatomical study included 30 soft cadavers. Ultrasound-guided dye injection was performed in legs of 10 cadavers after identifying the position of the ABTN and surrounding structures, followed by dissection to assess its spread. Clinical study was conducted in 15 patients undergoing total knee arthroplasty (TKA) with ultrasound-guided injection in the iPACK. All patients also received continuous adductor canal block. Sensorimotor function of the tibial and common peroneal nerves was determined. RESULTS: In the distal portion of the popliteal fossa, the tibial nerve and popliteal vessels ran superficially and closely together. The trajectory of ABTN ran lateral to the popliteal vasculature, forming a plexus towards the posterior capsule of the knee below the medial side of the upper edge of lateral femoral condyle. In cadavers, the ABTN and surrounding area of the popliteal plexus were stained with dye after injection. In the clinical study, no patients experienced complete motor or sensory blocks. CONCLUSIONS: We described a modified iPACK technique injection at the level of the ABTN forming the popliteal plexus, and it may constitute an optional anesthetic regimen to promote early ambulation following TKA.
Arthroplasty, Replacement, Knee ; Cadaver ; Clinical Study ; Early Ambulation ; Humans ; Knee ; Leg ; Pain, Postoperative ; Peroneal Nerve ; Popliteal Artery ; Tibial Nerve

PURPOSE: This retrospective study reports the intermediate-term clinical outcomes including the practical function in daily and sports activities after total ankle arthroplasty for end-stage rheumatoid arthritis, as well as the effects of modification of perioperative anti-rheumatic medications. MATERIALS AND METHODS: Twelve patients were followed for a minimum of 2 years after total ankle replacement for end-stage rheumatoid arthritis. Perioperative anti-rheumatic medications in all patients were modified based on a specific guideline. Clinical evaluations consisted of American Orthopaedic Foot and Ankle Society (AOFAS) scores, Foot and Ankle Outcome Score (FAOS), and Foot and Ankle Ability Measure (FAAM) scores. Periodic radiographic evaluation was conducted to detect changes in ankle alignment and postoperative complications. RESULTS: Mean AOFAS, FAOS, and FAAM scores improved significantly from 37.5 to 81.2, 39.1 to 72.4, and 33.8 to 64.0 points at final follow-up, respectively (p<0.001). Functional outcomes in daily and sports activities at final follow-up were found to be 76.5 and 55.8 points for the FAOS and 70.5 and 57.5 points for the FAAM, respectively. As early postoperative complications, there was one case of local wound necrosis, one case of medial malleolar fracture, and one case of deep peroneal nerve injury. Radiological evaluation revealed two cases of asymptomatic heterotopic ossification and one case of progressive arthritis in the talonavicular joint. Reoperation was performed in only one patient (8.3%) with a medial soft tissue impingement at a mean of 35.6 months follow-up. CONCLUSION: Total ankle arthroplasty appears to be an effective surgical option for end-stage rheumatoid arthritis. Practical functions in daily and sports activities were significantly improved at intermediate-term follow-up. Modification of perioperative anti-rheumatic medications can be one of the solutions to reduce the postoperative complication rate.
Ankle ; Arthritis ; Arthritis, Rheumatoid ; Arthroplasty ; Arthroplasty, Replacement, Ankle ; Follow-Up Studies ; Foot ; Humans ; Joints ; Necrosis ; Ossification, Heterotopic ; Peroneal Nerve ; Postoperative Complications ; Reoperation ; Retrospective Studies ; Sports ; Wounds and Injuries

OBJECTIVE: To present the branching patterns and anatomical course of the common fibular nerve (CFN) and its relationship with fibular head (FH).METHODS: A total of 21 limbs from 12 fresh cadavers were dissected. The FH width (FH_width), distance between the FH and CFN (FH_CFN), and thickness of the nerve were measured. The ratio of the FH_CFN to FH_width was calculated as follows: < 1, cross type and ≥1, posterior type. Angle between the CFN and vertical line of the lower limb 5 cm proximal to the tip of the FH was measured. Branching patterns of the lateral cutaneous nerve of the calf (LCNC) were classified into four types according to its origin and direction as follows: type 1a, lateral margin of the CFN; type 1b, medial margin of the CFN; type 2, lateral sural cutaneous nerve (LSCN); and type 3, CFN and LSCN.RESULTS: In the cross type (15 cases, 71.4%), the ratio of FH_CFN/FH_width was 0.83 and the angle was 13.0°. In the posterior type (6 cases, 28.6%), the ratio was 1.04 and the angle was 11.0°. In the branching patterns of LCNC, type 2 was the most common (10 cases), followed by types 1a and 1b (both, 5 cases).CONCLUSION: Location of the CFN around the FH might be related to the development of its neuropathy, especially in the cross type of CFN. The LCNC showed various branching patterns and direction, which could be associated with difficulties of electrophysiologic testing.
Cadaver ; Extremities ; Fibula ; Head ; Lower Extremity ; Peroneal Nerve

STUDY DESIGN: Retrospective study (level of evidence=3). PURPOSE: We examine the relationship between residual symptoms after discectomy for lumbar disc herniation and peripheral nerve (PN) neuropathy. OVERVIEW OF LITERATURE: Patients may report persistent or recurrent symptoms after lumbar disc herniation surgery; others fail to respond to a variety of treatments. Some PN neuropathies elicit symptoms similar to those of lumbar spine disease. METHODS: We retrospectively analyzed data for 13 patients treated for persistent (n=2) or recurrent (n=11) low back pain (LBP) and/or leg pain after primary lumbar discectomy. RESULTS: Lumbar re-operation was required for four patients (three with recurrent lumbar disc herniation and one with lumbar canal stenosis). Superior cluneal nerve (SCN) entrapment neuropathy (EN) was noted in 12 patients; SCN block improved the symptoms for eight of these patients. In total, nine patients underwent PN surgery (SCN-EN, n=4; peroneal nerve EN, n=3; tarsal tunnel syndrome, n=1). Their symptoms improved significantly. CONCLUSIONS: Concomitant PN disease should be considered for patients with failed back surgery syndrome manifesting as persistent or recurrent LBP.
Diskectomy ; Failed Back Surgery Syndrome ; Humans ; Leg ; Low Back Pain ; Lumbosacral Region ; Nerve Compression Syndromes ; Peripheral Nerves ; Peripheral Nervous System Diseases ; Peroneal Nerve ; Retrospective Studies ; Spine ; Tarsal Tunnel Syndrome

Common peroneal nerve (CPN) injury associated with multiple-ligament knee injury is relatively rare. A 38-year-old male presented with left knee pain occurred during ssireum (Korean wrestling). The patient exhibited positive Lachman, grade 3 varus stress, and also positive dial testing at 30°. Sensory loss of some area of left foot and foot drop were observed. Magnetic resonance imaging showed complete anterior cruciate ligament (ACL) rupture and posterolateral corner (PLC) injury. Motor nerve conduction velocity indicated left CPN palsy. ACL and PLC reconstructions were performed 10 days after injury and nerve exploration was done simultaneously. Neurolysis and primary repair were also performed. At 26 months after injury, muscle power of the tibialis anterior and extensor hallucis longus improved to grade 3, and sensation in CPN area recovered to about 60%. There was good stability in injured knee. To the best of our knowledge, this is the first case report describing CPN palsy with multiple-ligament knee injury during ssireum.
Adult ; Anterior Cruciate Ligament ; Foot ; Humans ; Knee Injuries ; Knee* ; Ligaments* ; Magnetic Resonance Imaging ; Male ; Neural Conduction ; Paralysis* ; Peroneal Nerve* ; Rupture ; Sensation

During routine dissection, additional muscular head of extensor digitorum brevis muscle attaching to the third toe and accessory muscle perforated by the branch of the deep peroneal nerve were observed in the right foot of a 71-year-old male cadaver. The additional muscular head originated from the dorsal surface of cuboid bone, and ran parallel with the third tendon of the extensor digitorum brevis muscle. It was conjoined with the third tendon of extensor digitorum brevis at the middle of its course. The accessory muscle was a small muscle which was covered with the muscle belly of the extensor hallucis brevis muscle. It originated from the dorsal surface of the calcaneus, and inserted to the lateral one-third of transverse retinacular band. These two variants were innervated by the branches of deep peroneal nerve. The branches of deep peroneal nerve were compressed under the tendon of extensor hallucis brevis and around the site where the nerve branch perforated the small muscle. The clinical significances of these variations and tendon of extensor hallucis brevis muscle were discussed.
Aged ; Cadaver ; Calcaneus ; Foot ; Head ; Humans ; Male ; Peroneal Nerve ; Tarsal Bones ; Tarsal Tunnel Syndrome* ; Tendons ; Toes

OBJECTIVE: In Asians, kneeling and squatting are the postures that are most often induce common peroneal neuropathy. However, we could not identify a compatible compression site of the common peroneal nerve (CPN) during hyper-flexion of knees. To evaluate the course of the CPN at the popliteal area related with compressive neuropathy using magnetic resonance imaging (MRI) scans of healthy Koreans.METHODS: 1.5-Tesla knee MRI scans were obtained from enrolled patients and were retrospectively reviewed. The normal populations were divided into two groups according to the anatomical course of the CPN. Type I included subjects with the CPN situated superficial to the lateral gastocnemius muscle (LGCM). Type II included subjects with the CPN between the short head of biceps femoris muscle (SHBFM) and the LGCM. We calculated the thickness of the SHBFM and posterior elongation of this muscle, and the LGCM at the level of femoral condyles. In type II, the length of popliteal tunnel where the CPN passes was measured.RESULTS: The 93 normal subjects were included in this study. The CPN passed through the “popliteal tunnel” formed between the SHBFM and the LGCM in 36 subjects (38.7% type II). The thicknesses of SHBFM and posterior portions of this muscle were statistically significantly increased in type II subjects. The LGCM thickness was comparable in both groups. In 78.8% of the “popliteal tunnel”, a length of 21 mm to < 40 mm was measured.CONCLUSION: In Korean population, the course of the CPN through the “popliteal tunnel” was about 40%, which is higher than the Western results. This anatomical characteristic may be helpful for understanding the mechanism of the CPNe by posture.
Asian Continental Ancestry Group ; Head ; Humans ; Knee ; Magnetic Resonance Imaging ; Nerve Compression Syndromes ; Peroneal Nerve ; Peroneal Neuropathies ; Posture ; Retrospective Studies