Atypical Origin of the Saphenous Nerve and a Variation of the Right Iliacus Muscle: A Case Report.

During a routine cadaveric dissection of the posterior abdominal wall, variations of the bilateral lumbar plexus and a variant saphenous nerve originating in the lower abdomen were noted and documented. The description of a saphenous nerve originating at the level of the lumbar plexus is, to the best of our knowledge, the first of its kind. Further study revealed more variations at the root of the lumbar plexus and bilateral branching patterns. A variant iliacus muscle entrapping the superior portion of the femoral nerve was also observed on the right side within the abdominal cavity. These variations are discussed in the context of risk of clinical intervention in this anatomical region..

Anatomical variation of the saphenous nerve path: A case report.

INTRODUCTION: The saphenous nerve has great importance on the sensitivity of the lower limb. In its normal course, it enters the adductor canal and travels under the sartorius muscle, on the medial side of the thigh. METHODS: The anatomical variation was found accidentally during routine cadaveric dissection of the thigh at the Human Anatomy Laboratory of the Department of Morphophysiology of the Faculty of Medical Sciences of Minas Gerais (FCMMG). RESULTS: A different pattern of path of the saphenous nerve was found, which appears to perforate the sartorius muscle. DISCUSSION: Complaints of pain in the lower limbs are highly prevalent in the adult population. Saphenous neuropathy is a pathological entity that is associated with such a clinic and may have compression or trauma as its etiology. In the context of compression, it can be caused due to the unusual nerve path, as described in the present study. In trauma, knowledge of this variation is important to prevent iatrogenic damage to nervous tissue during surgical procedures. CONCLUSION: The anatomic variation presented may be related to the symptom of pain in the lower limbs and is also relevant in the surgical context, in order to prevent complications.

Minimum Effective Analgesic Concentration of Ropivacaine in Saphenous Block Guided by Ultrasound for Knee Arthroscopic Meniscectomy: Randomized, Double-Blind Study.

BACKGROUND: After knee surgery, analgesia should be effective for mobilization and discharge. AIM OF THE STUDY: The primary objective of this study was to achieve the lowest effective analgesic concentration (MEC50 and MEC90) of ropivacaine for saphenous nerve block in arthroscopic meniscectomy. The secondary objective was to determine whether the block causes muscle weakness in the postoperative period. METHODS: The study was randomized, comparative, and double-blind. Fifty-one patients between 18 and 65 years old of both sexes, ASA I or II, who underwent knee arthroscopic meniscectomy at São Domingos Hospital were included. Patients underwent saphenous nerve block with 10 mL of ropivacaine administered by using the up-and-down method. The ropivacaine concentration was determined based on the previous patient's response (a biased-coin up-down design sequential method). If a patient had a negative response, the concentration of ropivacaine was increased by 0.05% in the next patient; if the response was positive, the next patient was randomized to be administered the same concentration of ropivacaine or a 0.05% lower concentration. Successful block was defined as pain <4 during 6 h. Patients underwent general anesthesia with 30 µg/kg alfentanil and propofol and maintenance with propofol, and, if necessary, remifentanil was administered. Postoperative analgesia was complemented with dipyrone, and if necessary, tramadol (100 mg) could be used. The following parameters were assessed: the success of the block; pain intensity after 2, 4, and 6 h; the consumption of remifentanil; time to the first analgesic supplementation; percent of patients who needed analgesics during 6h; and muscle strength. RESULTS: The MEC50 of ropivacaine was 0.36%, and the MEC90 was 0.477%. The block was successful in 45 patients. CONCLUSION: Saphenous block with 10 mL of 0.36% ropivacaine provides adequate analgesia for outpatient meniscectomy.

A Comparison between Oblique and Vertical Incisions on the Hamstring Tendon Harvesting in Anterior Cruciate Ligament Reconstruction and Infrapatellar Branch Injury of the Saphenous Nerve / Uma comparação entre incisões oblíquas e verticais na coleta do tendão dos isquiotibiais na reconstrução do LCA e na lesão do ramo infrapatelar do nervo safeno

Abstract Objective The present study aimed to compare the oblique and vertical incisions in hamstring tendon harvesting in anterior cruciate ligament (ACL) reconstruction and in infrapatellar branch injury of the saphenous nerve. Methods The present study was conducted at a tertiary referral center for 12 months. Patients with an indication of reconstruction of ACL tear were included in the study, who were then randomized into two groups (vertical [VG] and oblique [OG] groups). After excluding a few cases, 92 patients were eligible for further analysis (VG: n= 44; OG: n = 48). They were followed-up for 9 months after the surgery, and loss of sensation over the knee and over the proximal aspect of the operated leg was recorded. Results The mean lengths of the incisions were 27 mm and 38 mm for the OG and VG groups, respectively. The total rate of hypoesthesia was 40% (27 patients). A total of 12 (25%) and 25 patients (56.8%) on the OG and VG groups, respectively, reported hypoesthesia symptoms. The presence of hypoesthesia in patients in the VG group was two times higher than in the OG group. No statistical correlation was observed between the nerve injury and age, gender, education, and delay from injury to reconstruction. Conclusion Oblique incision, which showed lower risk of nerve damage, might be more recommended for graft harvesting. Patients who underwent reconstruction of the ACL in the OG group had a lower incidence of peri-incisional hypoesthesia when compared to those in the VG group.

Resumo Objetivo O presente estudo teve como objetivo comparar as incisões oblíquas e verticais na coleta dos tendões dos isquiotibiais na reconstrução do ligamento cruzado anterior (LCA) e na lesão do ramo infrapatelar do nervo safeno. Métodos O presente estudo foi realizado em um centro de referência terciário por 12 meses. Pacientes com indicação de reconstrução de uma ruptura do LCA foram incluídos no estudo, os quais foram randomizados em dois grupos (vertical [GV] e oblíquo [GO]). Após a exclusão de alguns casos, 92 pacientes foram elegíveis para análise posterior (GV: n= 44; GO: n = 48). Eles foram acompanhados por 9 meses após a cirurgia, e a perda de sensibilidade sobre o joelho e sobre o aspecto proximal da perna operada foi registrado. Resultados Os comprimentos médios da incisão foram de 27 mm e 38 mm para os grupos GO e GV, respectivamente. A taxa total de hipoestesia foi de 40% (27 pacientes). Um total de 12 (25%) e de 25 pacientes (56,8%) dos grupos GO e GV, respectivamente, relataram sintomas de hipoestesia. A presença de hipoestesia em pacientes no grupo GV foi duas vezes maior do que no grupo GO. Não foi observada correlação estatística entre a lesão do nervo e idade, gênero, escolaridade e demora entre a lesão e a reconstrução. Conclusão A incisão oblíqua, que apresentou menor risco de lesão nervosa, pode ser mais recomendada para a coleta do enxerto. Pacientes submetidos à reconstrução do LCA no grupo GO tiveram menor incidência de hipoestesia peri-incisional quando comparados aos pacientes do grupo GV.

Complementary Saphenous Nerve Block to Intra-Articular Analgesia Reduces Pain After Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: Numerous strategies exist for pain management after total knee arthroplasty (TKA), with a fast recovery and early ambulation required for full function. Currently, there is no universal standard of care to facilitate this management. We assessed pain management safety and efficacy after TKA, using intra-articular infiltration associated with peripheral saphenous nerve block (SNB) vs intra-articular infiltration alone. METHODS: We performed a controlled, double-blinded, and randomized trial to evaluate postoperative pain in TKA. One group was treated with intra-articular analgesia associated with SNB, whereas a second group received the same intra-articular cocktail, associated with placebo. Efficacy was evaluated according to average pain, pain-free time, and morphine rescue indices. Safety was assessed by intervention complications and surgery. RESULTS: About 70 patients were recruited. At time 0 (immediately postoperative), 51.43% of the intra-articular analgesia + placebo group presented pain <3, whereas in the intra-articular analgesia + SNB group, 8.82% (P = .001) presented with pain. This difference was maintained at 6, 12, and 24 hours, postoperatively. After 24 hours, the placebo group received an average 0.66 morphine rescues (standard deviation, 0.86), when compared with the SNB group that received 0.14 rescues (standard deviation, 0.43), (P = .002). We recorded a paresis of the external popliteal sciatic nerve, with spontaneous recovery without other complications. CONCLUSION: Complementary SNB to intra-articular analgesia was more effective in reducing average pain and the amount of pain-free time in the first 24 hours after TKA, with fewer requests for morphine rescue analgesia.

Neuralgia del nervio safeno interno en pacientes operados de várices esenciales en miembros inferiores / Neuralgia of the Internal Saphenous Nerve in Patients Operated on for Essential Varicose Veins of the Lower Limbs

Introducción: La neuralgia del nervio safeno interno, possafenectomía, constituye la expresión natural de una lesión nerviosa de tipo troncular periférico y constituye un síndrome clínico frecuente pero poco estudiado desde todos los puntos de vista. Objetivo: Valorar la neuralgia del safeno interno en los pacientes operados de várices esenciales en miembros inferiores. Método: Se realizó un estudio descriptivo- retrospectivo en 60 pacientes operados (stripping o flebo-extracción) en el servicio de Angiología y Cirugía Vascular del Hospital Docente Clinicoquirúrgico "General Freyre de Andrade" con el diagnóstico de várices esenciales en los miembros inferiores y presencia de neuralgia del nervio safeno interno. El estudio se realizó de enero a diciembre de 2017. Las variables estudiadas fueron: sexo, localización de la safenectomía (izquierda, derecha, bilateral), presencia de neuralgia en el nervio safeno interno. Se trabajó con valores de frecuencias absolutas y relativas. Resultados: 40 por ciento de las safenectomías fueron bilaterales; 31,6 por ciento en miembro inferior derecho y 28,3 por ciento en el miembro inferior izquierdo. El 80 por ciento eran mujeres (25 por ciento lado izquierdo, 25 por ciento lado derecho y 50 por ciento bilateral) y el 20 por ciento hombres (58,3 por ciento lado derecho y 41,7 por ciento lado izquierdo). Pacientes con neuralgia del safeno interno 23,3 por ciento (41,7 por ciento hombres y 18,8 por ciento mujeres). Conclusión: El reconocimiento adecuado de la neuralgia del safeno interno permite excluir otras complicaciones de tipo vascular y establecer medidas profilácticas para evitarla(AU)

Introduction: Post-saphenectomy neuralgia of the internal saphenous nerve is the natural expression of a peripheral truncal nerve injury and constitutes a frequent clinical syndrome; however, it is rarely studied, from all points of view. Objective: To assess neuralgia of the internal saphenous nerve in patients operated on for essential varicose veins of the lower limbs. Method: A descriptive-retrospective study was carried out in 60 surgically intervened patients (stripping or phlebo-extraction) in the angiology and vascular surgery service of Freyre de Andrade Clinical-Surgical Teaching Hospital for a diagnosis of essential varicose veins of the lower limbs and manifestation of neuralgia of the internal saphenous nerve. The study was carried out from January to December 2017. The variables studied were sex, location of the saphenectomy (left, right, or bilateral), and manifestation of neuralgia in the internal saphenous nerve. We worked with absolute and relative frequency values. Results: 40 percent of the saphenectomies were bilateral, 31.6 percent were performed in the lower right limb, and 28.3percent corresponded to the lower left limb. 80 percent were women (left side: 25 percent, right side: 25 percent, and bilateral: 50 percent) and 20 percent were men (right side: 58.3 percent, and left side: 41.7 percent). Patients with neuralgia of the internal saphenous never accounted for 23.3 percent (41.7 percent were men and 18.8 percent were women). Conclusion: The correct identification of neuralgia of the internal saphenous nerve allows to exclude other vascular complications and to establish prophylactic measures to avoid it(AU)

Anatomical study of the infrapatellar branch of the saphenous nerve with applications to knee surgery / Estudio anatómico de la rama infrapatelar del nervio safeno con aplicaciones a la cirugía de rodilla

The infrapatellar branch of the saphenous nerve is a cutaneous nerve that innervates the area surrounding the patella and contributes to the peripatellar plexus. This nerve is target to iatrogenic injuries during a great deal of knee procedures, such as tendon harvesting, total knee arthroplasty and medial arthroscopic approaches to the knee. Lesion to this nerve can produce sensorial loss at its innervation territory. The study conducted herein aims to observe the anatomical aspects of the infrapatellar branch in cadaveric specimens. The infrapatellar branch of the saphenous nerve of 40 male cadavers was dissected with the purpose of identifying the number of branches, its relation with the patella, tibial tuberosity and sartorius muscle. The nerve was dissected and several measurements were performed with the aid of a digital caliper. Statistical analysis was performed with the MedCalc 16.1 software. The infrapatellar branch of the saphenous nerve was present in 100 % of the sample. Its mean distance from its origin to its branching point was 16.35±6.48 mm on the right and 21.94±4.31 mm on the left, with statistically significant differences (p < 0.05). A relatively safe zone for surgery was observed on the superior and medial aspect of the patella, which received less branches.

La rama infrapatelar del nervio safeno es un nervio cutáneo que inerva el área que rodea la patela y contribuye al plexo peripatelar. Este nervio es objeto de lesiones iatrogénicas durante una gran cantidad de procedimientos de rodilla, como la extracción de tendones, la artroplastía total de rodilla y los abordajes artroscópicos mediales de la rodilla. La lesión de este nervio puede producir pérdida sensorial en su territorio de inervación. El estudio realizado aquí tiene como objetivo observar los aspectos anatómicos de la rama infrapatelar en muestras de cadáveres. La rama infrapatelar del nervio safeno de 40 cadáveres masculinos se disecó con el propósito de identificar el número de ramas, su relación con la patela, la tuberosidad tibial y el músculo sartorio. Se disecó el nervio y se realizaron varias mediciones con la ayuda de un calibrador digital. El análisis estadístico se realizó con el software MedCalc 16.1. La rama infrapatelar del nervio safeno estaba presente en el 100 % de las muestras. La distancia media desde su origen hasta su punto de ramificación fue de 16,35±6,48 mm a la derecha y de 21,94±4,31 mm a la izquierda, con diferencias estadísticamente significativas (p <0,05). Se identificó una zona relativamente segura para la cirugía en el aspecto superior y medial de la patela, que recibió menos ramas.

Hind limb sensory innervation in rats: comparison between sural and saphenous nerve morphometry / Inervación sensorial de los miembros posteriores en ratas: comparación morfométrica entre los nervios sural y safeno

Although numerous studies investigate sensory recovery of the hind paw of the rat after nerve damage, still no comprehensive overview of its normal innervation is present in the literature. We investigated the morphometry of myelinated fibers in the sural and saphenous nerves and analyzed their size distributions in young rats. Six 30-day-old female Wistar rats were perfused with 2.5% glutaraldehyde and their right and left sural and saphenous nerves were prepared for light microscopy and morphometry. Morphometric data were compared between segments (proximal versus distal) and sides (right versus left) for the same nerves. Also, segments from right or left sides were compared between nerves (sural versus saphenous). Both, the sural and saphenous nerves, exhibited proximal to distal symmetry on both sides as well as left-right symmetry. Histograms of the diameter of the myelinated fibers were unimodal in both nerves, regardless of segments or sides with the peaks of the fibers size occurring between 2.5 and 4.0 µm. The axon distributions reflected the myelinated fiber distributions, with the sural and saphenous nerves peaking between 1.5 and 2.0 µm. The G ratio (the ratio between the axon and fiber diameters) distributions were also unimodal, with peaks at 0.6 for both nerves. This study contributes to the literature with information on the myelinated fibers morphometry from the two sensory nerves responsible for the rat hind limb innervation. This information is valuable for a better understanding of the possible contribution of collateral sprouting from the sural or saphenous nerves on the paw sensory territory recovery observed after one of these nerves is damaged.

Aunque numerosos estudios investigan la recuperación sensorial del miembro pélvico o posterior de la rata después del daño en los nervios, aún no existe en la literatura una visión global de su inervación normal. Investigamos la morfometría de fibras mielínicas de los nervios sural y safeno y analizamos sus distribuciones de tamaño en ratas jóvenes. Seis ratas Wistar de 30 días de edad fueron perfundidas con 2,5% de glutaraldehído, se prepararon los nervios sural y safeno derecho e izquierdo para microscopía de luz y morfometría. Datos morfométricos fueron comparados entre los segmentos (proximal vs distal) y laterales (derecho vs izquierdo) para los mismos nervios. Además, los segmentos de los lados derecho e izquierdo se compararon entre los nervios (sural vs safeno). Ambos nervios sural y safeno exhibieron una simetría proximal a distal en ambos lados, así como una simetría izquierda-derecha. Histogramas del diámetro de las fibras mielinizadas eran unimodales en ambos nervios, independientemente de los segmentos o de los lados, siendo los peaks del tamaño de las fibras entre 2,5 y 4,0 micras. Las distribuciones de los axones reflejan las distribuciones de fibras mielinizadas, de los nervios sural y safeno que alcanzaban entre 1,5 and 2,0 µm. La relación de G (relación entre los diámetros de los axones y de fibra) eran también unimodales, alcanzando 0,6 para ambos nervios. Este estudio contribuye a la literatura con los datos de la morfometría de fibras mielinizadas de ambos nervios sensoriales responsables de la inervación de la extremidad pélvica de la rata. Esta información es valiosa para una mejor comprensión de los nervios sural y safeno en la recuperación sensorial del miembro después de que uno de estos nervios ha sido dañado.

Sartorial branch of saphenous nerve: anatomical relationship with bony landmarks and great saphenous vein / Ramo sartorial del nervio safeno safeno: relación anatómica con puntos de referencia óseos y de la vena safena magna

Sartorial branch of saphenous nerve (medial crural cutaneous nerve) originates at the medial side of the knee and descends along the great saphenous vein (GSV) to innervate the medial aspect of the leg. Its anatomy is of concern in surgical procedures and anesthetic block. However, the measurement data related to palpable bony landmarks with comparison between sexes and sides are lacking. Dissection was done in 95 lower limbs from both sexes. We found that the nerve pierced the deep fascia alone in most cases (92.6%). This piercing point was always distal to the adductor tubercle with the distance of 5-6 cm which was 15% of the leg length (the distance between the adductor tubercle and medial malleolus). The nerve was 7 cm medial to the tibial tuberosity. At the mid-level of leg length, the nerve was slightly over 4 cm medial to the anterior tibial margin. The nerve terminally divided 7 cm proximal to the medial malleolus. Furthermore, the anatomical relationship between the nerve and the GSV was highly variable. The nerve was constantly anterior, posterior or deep to the GSV in 8.4%, 15.8% and 2.1%, respectively. Crossing between the two structures was observed in 57.9% of specimens and the distance to the medial malleolus was 18 cm. Symmetry was found in most parameters and significant gender differences were observed in some distances. These results are important for avoiding the sartorial nerve injury and locating the nerve during relevant procedures.

El ramo sartorial del nervio safeno (nervio cutáneo medial de la pierna) se origina en el lado medial de la rodilla y desciende a lo largo de la vena safena magna (VSM) para inervar la cara medial de la pierna. Su anatomía es motivo de preocupación en los procedimientos quirúrgicos y en el bloqueo anestésico. Sin embargo, los datos de medición relacionados con puntos de referencia óseos palpables y la comparación entre los lados y en ambos sexos son escasas. Se realizó la disección en 95 miembros inferiores de ambos sexos. Se encontró que el nervio perforó la fascia profunda en la mayoría de los casos (92,6%). Esta punta de perforación fue siempre distal al tubérculo del músculo aductor magno a una distancia de 5-6 cm, que representaba el 15% del largo de la pierna (la distancia entre el tubérculo del aductor magno y el maléolo medial). El nervio se localizaba 7 cm medial a la tuberosidad tibial. Al nivel del tercio medio en ambas piernas, el nervio estaba a una distancia un poco mayor a 4 cm medial al margen anterior de la tibia. El nervio se dividía 7 cm proximal al maléolo medial. Por otra parte, la relación anatómica entre el nervio y la VSM fue muy variable. El nervio era constantemente anterior, posterior o profundo a la VSM en 8,4%, 15,8% y 2,1%, respectivamente. Cruce entre las dos estructuras anatómicas se observó en el 57,9% de las muestras y la distancia hasta el maléolo medial fue de 18 cm. La simetría se encuentra en la mayoría de los parámetros y diferencias de sexo significativas se observaron en algunas distancias. Estos resultados son importantes para evitar la lesión del nervio sartorial y localizar el nervio durante los procedimientos pertinentes.

Relaciones anatómicas de la vena safena magna con el nervio safeno a nivel talocrural / Anatomical relations of the saphenous magna vein with saphenous nerve at the talocrural level

La relación anatómica de la vena safena magna (VSM) y del nervio safeno (NS) en la región talocrural tiene importancia anatomoclínica, sin embargo existen pocos trabajos en la literatura anatómica. Se disecaron 30 pies de cadáveres formolizados de individuos adultos de ambos sexos, describiéndose el origen de la VSM y su relación con el NS en la región talocrural; se midió la distancia entre el NS y la VSM a nivel del ápice, margen anterior y a 1 cm del margen superior del maléolo medial. La VSM se originaba de la unión de la vena marginal medial del pie y el plexo venoso dorsal. La relación anatómica entre la VSM y el NS es variada, cursando el NS en un 63,3 por ciento anterior y 30 por ciento posterior a la VSM y en 6,7 por ciento el NS se dividía en dos ramos los cuales acompañaban anterior y posteriormente a la VSM. La distancia de la VSM y del NS al ápice del maléolo medial fue de 10,75 mm +/- 3,06 y 13,38 +/- 2,82 mm, respectivamente. La distancia de la VSM al margen anterior del maléolo medial fue de 0,53 mm +/- 0,51. Es importante conocer las relaciones de la VSM y del NS para su aplicación clínica, especialmente, en el momento de elegir un acceso venoso periférico no tan frecuente como las venas de la región talocrural.

Despite the clinical and anatomical significance of the anatomical relationship ofthesaphena magna vein (SMV)and thesaphenous nerve in (SN) in the talocrural region there are few studies in the literature. Thirty feet of adult formolized cadavers of both sexes were dissected describing the origin of the SMV and its relation with the SN in the talocrural region. Distance between the SN and the SMV was measured at the apex level, anterior margin and at 1 cm from the upper margin. The SMV originated from the medial marginal vein and dorsal venous arch. Anatomical relation between the SMV and the SN is varied, traveling anterior the SN 63.3 percent, and posterior the SMV 30 percent; in 6.7 percent the SN divided in two branches which joined anterior and posterior to the SMV. The distance of the SMV and the SN medial malleolus apex was 10.75mm +/- 3.06 and 13.38 +/- 2.82 mm. SMV distance to anterior margin of the medial malleolus was 0.53 mm +/- 0.51. The relation between the SMV and SN is important for clinicians particularly at the time of determining peripheral venous access not as frequent in veins of the talocrural region.

Traumatic lesions of internal saphenous nerve and branches / Lesões traumáticas do nervo safeno interno e seus ramos

OBJECTIVE: To show a rare lesion that sometimes simulates vascular disorder of the lower extremities. METHOD: Three patients were operated and the follow-up period was eight months, the surgical technique was neurotomy of the infrapatellar and descendent branches. RESULTS: In two cases there were almost total pain resolution, and in other case improvement only. CONCLUSION: Surgical treatment yields good results in this type of internal saphenous nerve lesion, and could be useful as an alternative to conservative treatment.

OBJETIVO: Apresentar lesões raras do nervo safeno interno interno, que muitas vezes, simulam doenças vasculares dos membros inferiores. MÉTODO: Três pacientes foram operados e acompanhados por um período de oito meses. A técnica cirúrgica consistiu na neurotomia dos ramos infrapatelar e descendente do nervo safeno interno. RESULTADOS: Nos dois primeiros casos houve quase desaparecimento total da dor em pouco tempo e no terceiro apenas melhora. CONCLUSÃO: O tratamento cirúrgico dá bons resultados neste tipo de lesão do nervo safeno interno e poderia ser útil como alternativa ao tratamento conservador.