Medial plantar nerve: normative parameters of an electroneuromyographic study in adults

Background. The study of the sensitive portion of the medial plantar nerve is relevant not only in the examination of patients with tibial nerve mononeuropathy or its branches, but also in the diagnosis of polyneuropathies.Objective: to analyze the normative parameters of the sensory potential recorded during the study of the medial plantar nerve by the orthodromic method in healthy adults.Materials and methods. 126 sensitive fibers of the medial plantar nerves were studied on the Dantec Keypoint G4 device (Denmark) in 63 healthy individuals (31 men and 32 women; age from 20 to 80 years). 3 groups were identified taking into account age: group 1 included healthy people aged 20 to 39 years (n = 23); group 2 consisted of people aged 40 to 60 years (n = 20); and 3 – older than 60 years (n = 20). The parameters of the sensory potential of the medial plantar nerve are analyzed.Results. The sensory potential in the study of the sensitive portion of the medial plantar nerve was registered in all 126 healthy subjects. Comparative statistical analysis did not demonstrate significant differences between groups 1–3 in the values of such parameters of the sensory potential as the latency of the onset, the duration of the negative phase and the rate of propagation of excitation. At the same time, in groups 2 and 3, the magnitude of the amplitude from peak to peak of the sensory potential was significantly lower compared to group 1, and averaged 8.92 and 7.86 MV, respectively.Conclusion. Knowledge of the regulatory parameters will allow expanding the use of electroneuromyography of the sensitive portion of the medial plantar nerve in clinical and research practice.

Schwannoma of the medial plantar nerve: a case report

We report the case of a 60-year-old woman with a schwannoma of the medial plantar nerve. She presented with the complaint of pain for about 2 years and a painful lesion in the medial plantar region of the left forefoot and on the second toe. Physical examination showed well-defined, firm tumor masses painful to palpation on the medial and plantar surface of the left forefoot and second toe. We surgically explored the area and excised 3 lesions, resulting in complete pain relief and no aesthetic complaints. Schwannomas of the medial plantar nerve are rare tumors, with only a few reports of cases extending to the forefoot. The finding of multiple schwannomas may be a red flag for the possible existence of local, painful, nerve lesions despite a negative Tinel sign. Appropriate surgical planning contributed to our successful intervention, without aesthetic, painful, or functional sequelae for the patient. Level of Evidence V; Therapeutic Studies; Expert Opinion.

MRI Study on Tibial Nerve of the Ankle Canal and Its Branches: A method of multiplanar reconstruction with 3D-FIESTA-C sequences

Background The display of tibial nerve and its branches in the ankle canal is helpful for the diagnosis of local lesions and compression, and also for clinical observation and surgical planning.The aim of this study was to investigate the feasibility of three-dimensional dual-excitation balanced steady-state free precession sequence (3D-FIESTA-C) multiplanar reconstruction (MPR) display of tibial nerve and its branches of the ankle canal. Methods The subjects were 20 healthy volunteers (40 ankles), aged 22–50, with no history of ankle joint desease. 3D-FIESTA-C sequence was used in the 3.0t magnetic resonance equipment for imaging. During the scanning, each foot was at a 90-degree angle to the tibia.The tibial nerve of the ankle canal and its branches were displayed and measured at the same level through multiplanar reconstruction. Results Most of the tibial nerve bifurcation points were located in the ankle canal (57.5%), few (42.5%) were located at the proximal end of the ankle canal, and none was found away from the distal end. The bifurcation between the medial plantar nerve and the lateral plantar nerve is on the line between the tip of the medial malleolus and the calcaneus, and it’s angle is between 6° and 35°.The average cross-sectional diameter of the medial plantar nerve is about mm, and the lateral plantar nerve about mm. In MPR images, the display rates of both the medial calcaneal nerve and the subcalcaneal nerve were 100%, and the starting point of the subcalcaneal nerve was always at the distal end of the starting point of the medial calcaneal nerve. In 55% of cases, there were more than 2 medial calcaneal nerve innervations. Conclusion The 3D-FIESTA-C MPR can display the morphological features and positions of tibial nerve and its branches and the bifurcation point’s projection position on the body surface can be marked. This method not only benefited the imaging diagnosis of tibial nerve and branch-related lesions of the ankle canal, but also provided a good imaging basis to plan the clinical operation of the ankle canal and avoid surgical injury.

MRI Study on Tibial Nerve of the Ankle Canal and Its Branches: A method of multiplanar reconstruction with three-dimensional dual-excitation balanced steady-state free precession sequence

Background: The display of tibial nerve and its branches in the ankle canal is helpful for the diagnosis of local lesions and compression, and also for clinical observation and surgical planning.The aim of this study was to investigate the feasibility of three-dimensional dual-excitation balanced steady-state free precession sequence (3D-FIESTA-C) multiplanar reconstruction (MPR) display of tibial nerve and its branches of the ankle canal.The subjects were 20 healthy volunteers (40 ankles), aged 22-50, with no history of ankle joint desease. 3D-FIESTA-Csequence was used in the 3.0t magnetic resonance equipment for imaging. During the scanning, each foot was at a 90-degree angle to the tibia so that the results of measurement are more accurate .The tibial nerve of the ankle canal and its branches were displayed and measured at the same level through multiplanar reconstruction.Results: Most of the tibial nerve bifurcation points were located in the ankle canal (57.5%), few (42.5%) were located at the proximal end of the ankle canal, and none was found away from the distal end. The bifurcation between the medial plantar nerve and the lateral plantar nerve is on the line between the tip of the medial malleolus and the calcaneus, and it’s angle is between 6° and 35°.The average cross-sectional diameter of the medial plantar nerve is about mm, and the lateral plantar nerve about mm. In MPR images, the display rates of both the medial calcaneal nerve and the subcalcaneal nerve were 100%, and the starting point of the subcalcaneal nerve was always at the distal end of the starting point of the medial calcaneal nerve. In 55% of cases, there were more than 2 medial calcaneal nerve innervations.Conclusion: The 3D-FIESTA-C MPR can display the morphological features and positions of tibial nerve and its branches. By measuring the distance between each bifurcation point, the tip of the medial malleolus and the angle between this line and the horizontal line that passes the tip of the medial malleolus, the bifurcation point’s projection position on the body surface can be accurately marked. This method not only benefited the imaging diagnosis of tibial nerve and branch-related lesions of the ankle canal, but also provided a good imaging basis to plan the clinical operation of the ankle canal and avoid surgical injury.

An Anatomical Basis for the Myofascial Trigger Points of the Abductor Hallucis Muscle

Myofascial pain syndrome is characterized by pain and a limited range of joint motion caused by muscle contracture related to motor-end-plate dysfunction and the presence of myofascial trigger points (MTrPs). It is the most frequent cause of musculoskeletal pain, with a worldwide prevalence varying between 13.7% and 47%. Of the patients with myofascial pain syndrome, approximately 17% have pain in the medial hindfoot area. The abductor hallucis muscle is located in the medial, posterior region of the foot and is related to painful plantar syndromes. The objective of this study was to describe the distribution of the medial plantar nerve and their anatomical relationship with MTrPs found in the literature. Thirty abductor hallucis muscles were dissected from 15 human cadavers (8 males and 7 females). The muscles were measured, and the distribution data of the medial plantar nerve branches in each quadrant were recorded. For statistical analysis, we used generalized estimation equations with a Poisson distribution and a log logarithm function followed by Bonferroni multiple comparisons of the means. The data are expressed as the mean ± standard deviation. The level of significance was adjusted to 5% (p<0.05). A high concentration of nerve branches was observed in the first quadrant (Q1) of the abductor hallucis muscle, which is the same area in which the MTrPs are described. The topography of the entry points of the branches of the medial plantar nerve to the abductor hallucis muscle correlates with the topography of the muscular trigger points. The anatomical structure of the MTrPs may be useful for a better understanding of the pathophysiology of myofascial disorders and provide a basis for surgical and clinical treatments.

Plantar Flap for Foot Reconstruction

The medial plantar flap is an axial pattern flap from the non–weight-bearing area of the sole of the foot between the heel and the metatarsal heads. The flap can be raised as a pedicle or a free flap, based on either the medial or lateral plantar arteries, or both. Sensory function is provided by branches of the medial plantar nerve. The donor site defect in the foot has caused no difficulty except for occasional marginal hyperkeratosis.

Medial plantar nerve

Objective: To measure and evaluate the distance from the medial plantar nerve (MPN) to six predetermined anatomical landmarks, identifying 12 distances, and establish a correlation with the trajectory of the flexor hallucis longus (FHL) tendon, especially the knot of Henry, and the location of the bifurcation of the posterior tibial nerve (PTN) relative to the tarsal tunnel. Methods: A descriptive and quantitative study was conducted in which 15 adult feet (six right and nine left) from cadavers were dissected, and the anatomical relationship between the MPN and predetermined structures was evaluated. The distance from the medial border of the medial malleolus to the inferior calcaneal tuberosity [defined as a fixed reference (FR)] was measured to compensate for variability in foot size. Results: The results indicated that the bifurcation of the PTN was proximal to the tarsal tunnel in 11 feet (73.3%), within the tunnel in three feet (20%), and distal to the tunnel in one foot (6.66%). A statistically significant (p=0.035) association was found between the FR and the distance from the superior calcaneal tuberosity to the MPN, a strong correlation (p=0.004) was found between the FR and the distance from the inferior calcaneal tuberosity to the MPN, and a significant association (p=0.013) was found between the FR and the distance from the medial calcaneal tuberosity to the knot of Henry. Conclusion: Some anatomical structures, especially the knot of Henry, have a strong correlation with the MPN and should be considered by surgeons who intend to approach the FHL in the plantar region. Bifurcation of the PTN proximal to the tarsal tunnel was the most common presentation.Level of Evidence V; Expert opinion.