Does the L5 spinal nerve move? Anatomical evaluation with implications for postoperative L5 nerve palsy.

PURPOSE: While palsy of the L5 nerve root due to stretch injury is a known complication in complex lumbosacral spine surgery, the underlying pathophysiology remains unclear. The goal of this cadaveric study was to quantify movement of the L5 nerve root during flexion/extension of the hip and lower lumbar spine. METHODS: Five fresh-frozen human cadavers were dissected on both sides to expose the lumbar vertebral bodies and the L5 nerve roots. Movement of the L5 nerve root was tested during flexion and extension of the hip and lower lumbar spine. Four steps were undertaken to characterize these movements: (1) removal of the bilateral psoas muscles, (2) removal of the lumbar vertebral bodies including the transforaminal ligaments from L3 to L5, (3) opening and removing the dura mater laterally to visualize the rootlets, and (4) removal of remaining soft tissue surrounding the L5 nerve root. Two metal bars were inserted into the sacral body at the level of S1 as fixed landmarks. The tips of these bars were connected to make a line for the ruler that was used to measure movement of the L5 nerve roots. Movement was regarded as measurable when there was an L5 nerve excursion of at least 1 mm. RESULTS: The mean age at death was 86.6 years (range 68-89 years). None of the four steps revealed any measurable movement after flexion/extension of the hip and lower lumbar spine on either side (< 1 mm). Flexion of the hip and lower lumbar spine revealed lax L5 nerve roots. Extension of the hip and lower lumbar spine showed taut ones. CONCLUSION: Significant movement or displacement of the L5 nerve root could not be quantified in this study. No mechanical cause for L5 nerve palsy could be identified so the etiology of the condition remains unclear.

Fascia and soft tissues innervation in the human hip and their possible role in post-surgical pain.

Persistent symptoms, most commonly pain, may remain after otherwise successful hip replacement surgery. Innervation of fascia and soft tissues has become increasingly important in etiopathogenesis of pain, but the relative importance of the various anatomical structures in the hip region is still not known. Innervation of skin, superficial adipose tissue, superficial fascia, deep adipose tissue, deep fascia, muscles, capsule, capsule ligament, ligamentum teres, and tendon in the human hip from 11 patients and 2 cadavers were quantified by staining with anti-S100 antibody for myelin-forming Schwann cells, to obtain the percentage of antibody positivity, density and mean diameter of the nerve fibers. The skin was the most highly innervated (0.73% ± 0.37% of positive area in patients; 0.80% ± 0.28% in cadavers); the tendon was the least innervated (0.07% ± 0.01% in patients, 0.07% ± 0.007% in cadavers). The muscles (vasto-lateral and gluteus medius) were the second most innervated structure according the percentage (0.31% ± 0.13% in living humans, 0.30% ± 0.07% in cadavers), but with only a few nerves, with large diameters (mean diameter 36.4 ± 13.4 µm). Instead, the superficial fasciae showed 0.22% ± 0.06% and 0.26% ± 0.05% of positive areas in living humans and cadavers, respectively. Fasciae were invaded by networks of small nerve fibers, revealing a possible role in pain. The superficial fascia was the second most highly innervated tissue after the skin, with a density of 33.0 ± 2.5/cm2 , and a mean nerve sizes of 19.1 ± 7.2 µm. Lastly, the capsule turned out to be poorly innervated (0.09%), showing that its removal does not necessarily lead to painful consequences. Statement of clinical significance: Deeper knowledge about the innervation of the soft tissue in the human hip joint will enhance study and understanding of the best surgical procedures to follow during hip arthroplasty to reduce post-operative pain.

A safe percutaneous technique for the reduction of irreducible femoral neck fractures using ultrasound localization of the femoral vascular and nervous structures at the hip.

We present a safe percutaneous technique for the placement of Kirschner wires into the femoral head to assist in the reduction of irreducible femoral neck fractures using ultrasound to identify the vascular and nervous structures about the hip.From January 2011 to June 2014, a total of 36 patients (25 males and 11 females) were enrolled in this study. Patients were placed on a fracture reduction table for limb traction. After 3 unsuccessful reductions with limb traction, ultrasound-guided localization of the patient's femoral artery, vein, and nerve at the hip was performed. These structures were marked on the overlying skin and then Kirschner wires were inserted into the femoral head avoiding these marked structures. After the surgery, the Kirschner wire insertions were routinely reviewed by ultrasound, the hip fracture reduction and the femoral nerve sensorimotor function were routinely examined as well.All 36 patients with an irreducible variant of a femoral neck fracture showed anatomic reduction under C-arm fluoroscopy using ultrasound to avoid K wire injury to the femoral vascular structures and nerve. No major vascular injury during operation. In post-surgical ultrasound examination, local hematoma formation was not evident. There was normal function of the femoral nerve. On follow-up, there were no infections, wound problems, recurrence of fracture displacement, laxity, or implant breakage.Preoperative ultrasonic localization of the femoral artery, vein, and femoral nerve safely allowed. Kirschner wire placement under C-arm fluoroscopy into the femoral head to assist in fracture reduction. This assisted reduction method for irreducible femoral neck fractures had a number of advantages, including closed anatomic reduction with minimal attempts, used simple equipment, and avoided further destruction of the blood supply to the femoral head.

Update on Selective Regional Analgesia for Hip Surgery Patients.

In hip surgery, regional anesthesia offers benefits in pain management and recovery. There are a wide range of regional analgesic options; none have shown to be superior. Lumbar plexus block, femoral nerve block, and fascia iliaca block are the most supported by published literature. Other techniques, such as selective obturator and/or lateral femoral cutaneous nerve blocks, represent alternatives. Newer approaches, such as quadratus lumborum block and local infiltration analgesia, require rigorous studies. To realize long-term outcome benefits, postoperative regional analgesia must be tailored to the individual patient and last longer.

A comparison of the fascia iliaca block to the lumbar plexus block in providing analgesia following arthroscopic hip surgery: A randomized controlled clinical trial.

STUDY OBJECTIVE: This randomized controlled single blinded clinical trial compared the fascia iliaca block (FIB) and the lumbar plexus block (LPB) in patients with moderate to severe pain following hip arthroscopic surgery. DESIGN: Single blinded randomized trial. SETTING: Postoperative recovery area, postoperative days 0 and 1. PATIENTS: Fifty patients undergoing hip arthroscopy were approached in the Post Anesthesia Care Unit (PACU) if they had moderate to severe pain (defined as > or equal 4/10 on the numeric rating scale). Twenty-five patients were allocated to the FIB and twenty-five patients to the LPB. INTERVENTIONS: Fascia iliaca block or lumbar plexus block. MEASUREMENTS: A blinded observer recorded pain scores just prior to the block, 15 min following the block (primary endpoint), and then every 15 min for 2 h (or until the patient was discharged). Total PACU time and opioid use were recorded. Pain scores and analgesic use on postoperative day (POD) 0, and POD 1 were recorded. At 24 h post block the Quality of Recovery 9 questionnaire was administered. RESULTS: The mean pre-block pain scores were comparable between the two groups (P = 0.689). There was no difference in mean post block pain scores between the two groups at 15 min (P = 0.054). In the PACU patients who underwent a LPB consumed less opioids compared to FIB patients (P = 0.02), however no differences were noted between the two groups in PACU length of stay, or POD 0 or 1 opioid use. CONCLUSION: A fascia iliaca block is not inferior to a lumbar plexus block in reducing PACU pain scores in patients with moderate to severe pain following hip arthroscopic surgery and is a viable option to help manage postoperative pain following hip arthroscopic surgery.

Bilateral early activity in the hip flexors associated with falls in stroke survivors: Preliminary evidence from laboratory-induced falls.

OBJECTIVE: Falls are the most common and expensive medical complication following stroke. Hypermetric reflexes have been suggested to impact post-stroke balance but no study has evaluated reflex amplitudes under real conditions of falls in this population. Our objective was to quantify the early reflexive responses during falls induced in the laboratory. METHODS: Sixteen stroke survivors were exposed to posteriorly directed treadmill perturbations that required a forward step to maintain a balance. Perturbations differed in terms of treadmill translation displacement, velocity, and acceleration. EMG amplitudes were compared between Fall/Recovery trials, as well as Fallers/Non-Fallers at two different time windows: 50-75 and 75-100 ms. RESULTS: Sixteen of 86 trials resulted in falls by nine subjects (Fallers). While no differences were found between 50 and 75 ms, EMG amplitude in the paretic rectus femoris muscle was larger between 75 and 100 ms during Fall trials. Further, a bilateral increase in RF activity was seen in Fallers but not Non-Fallers. Interestingly, the bilateral increase was related to perturbation intensity (larger EMG activity with larger perturbations) in Fallers, but again not in Non-Fallers. CONCLUSIONS: Heightened early recovery hip flexor activity between 75 and 100 ms is associated with falls and Fallers post-stroke. SIGNIFICANCE: Though requiring replication and expanded subject pools, these preliminary results reflect a possible clinically meaningful relationship between heightened reflexive responses and fall risk. Future work should evaluate the underlying mechanisms driving these heightened reflexes (e.g. stretch, startle) such that future rehabilitation techniques can address this abnormal response.

Effect of aging on region-specific functional role and muscle geometry along human rectus femoris muscle.

INTRODUCTION: We compared the region-specific neuromuscular activation and muscle morphology along the rectus femoris (RF) muscle between young and elderly. METHODS: Ratios of surface electromyography amplitude between hip flexion and knee extension (HF/KE) were compared among regions along the muscle for 9 young and 9 elderly men. Muscle thickness was also compared among the regions. RESULTS: HF/KE in the proximal region was significantly greater than in the middle and distal regions for both the young and elderly (P < 0.05). However, a significant difference in HF/KE between the middle and distal regions was found in the young (P < 0.05), but not in the elderly (P > 0.05). A difference in the region-specific muscle thickness was observed between the young and elderly. CONCLUSION: These findings suggest that functional role and muscle morphology are regionally affected by aging along the RF muscle. Muscle Nerve 56: 982-986, 2017.

Reorganization of motor cortex and impairment of motor performance induced by hindlimb unloading are partially reversed by cortical IGF-1 administration.

Immobilization, bed rest, or sedentary lifestyle, are known to induce a profound impairment in sensorimotor performance. These alterations are due to a combination of peripheral and central factors. Previous data conducted on a rat model of disuse (hindlimb unloading, HU) have shown a profound reorganization of motor cortex and an impairment of motor performance. Recently, our interest was turned towards the role of insulin-like growth factor 1 (IGF-1) in cerebral plasticity since this growth factor is considered as the mediator of beneficial effects of exercise on the central nervous system, and its cortical level is decreased after a 14-day period of HU. In the present study, we attempted to determine whether a chronic subdural administration of IGF-1 in HU rats could prevent deleterious effects of HU on the motor cortex and on motor activity. We demonstrated that HU induces a shrinkage of hindlimb cortical representation and an increase in current threshold to elicit a movement. Administration of IGF-1 in HU rats partially reversed these changes. The functional evaluation revealed that IGF-1 prevents the decrease in spontaneous activity found in HU rats and the changes in hip kinematics during overground locomotion, but had no effect of challenged locomotion (ladder rung walking test). Taken together, these data clearly indicate the implication of IGF-1 in cortical plastic mechanisms and in behavioral alteration induced by a decreased in sensorimotor activity.

Distal Extension of the Direct Anterior Approach to the Hip: A Cadaveric Feasibility Study.

BACKGROUND: The direct anterior approach (DAA) is becoming more popular as the standard surgical approach for primary total hip arthroplasty. However, femoral complications of up to 2.8% have been reported. Therefore, it is important for surgeons to understand the periarticular neurovascular anatomy in order to safely deal with intraoperative complications. METHODS: Anatomic dissections were performed on 20 cadaveric hips. The neurovascular structures anterior to the femur and distal to the intertrochanteric line were dissected and its position was described in relation to anatomic landmarks easily identified through the DAA: anterior superior iliac spine (ASIS), the insertion of the gluteus minimus (GM), and the lesser trochanter (LT). RESULTS: Two clearly distinguishable neurovascular bundles running to the vastus lateralis were seen in 17 of 20 specimens. The average distances to the landmarks were as follows: ASIS-1st bundle = 12.3 cm (range, 9.7-14.5); GM-1st bundle = 3.2 cm (range, 2.2-4); LT-1st bundle = 1.6 cm (range, 0.7-2.8); 1st bundle-2nd bundle = 3.3 cm (range, 1.8-6.1). CONCLUSION: A consistent pattern of 2 clearly distinguishable neurovascular bundles was seen in 85% of the specimens. Knowledge of the position of these neurovascular bundles in relation to the anatomic landmarks makes distal femoral extension of the DAA feasible. Further clinical studies are needed to confirm the safety of the extensile anterior approach.

Sensorimotor integration of vision and proprioception for obstacle crossing in ambulatory individuals with spinal cord injury.

Skilled walking, such as obstacle crossing, is an essential component of functional mobility. Sensorimotor integration of visual and proprioceptive inputs is important for successful obstacle crossing. The objective of this study was to understand how proprioceptive deficits affect obstacle-crossing strategies when controlling for variations in motor deficits in ambulatory individuals with spinal cord injury (SCI). Fifteen ambulatory individuals with SCI and 15 able-bodied controls were asked to step over an obstacle scaled to their motor abilities under full and obstructed vision conditions. An eye tracker was used to determine gaze behaviour and motion capture analysis was used to determine toe kinematics relative to the obstacle. Combined, bilateral hip and knee proprioceptive sense (joint position sense and movement detection sense) was assessed using the Lokomat and customized software controls. Combined, bilateral hip and knee proprioceptive sense in subjects with SCI varied and was significantly different from able-bodied subjects. Subjects with greater proprioceptive deficits stepped higher over the obstacle with their lead and trail limbs in the obstructed vision condition compared with full vision. Subjects with SCI also glanced at the obstacle more frequently and with longer fixation times compared with controls, but this was not related to proprioceptive sense. This study indicates that ambulatory individuals with SCI rely more heavily on vision to cross obstacles and show impairments in key gait parameters required for successful obstacle crossing. Our data suggest that proprioceptive deficits need to be considered in rehabilitation programs aimed at improving functional mobility in ambulatory individuals with SCI. NEW & NOTEWORTHY: This work is unique since it examines the contribution of combined, bilateral hip and knee proprioceptive sense on the recovery of skilled walking function, in addition to characterizing gaze behavior during a skilled walking task in people with motor-incomplete spinal cord injury.

Adductor canal block for knee surgical procedures: review article.

Adductor canal block (ACB) has recently emerged as an alternative to femoral nerve block for pain control after various knee procedures especially knee arthroplasty. In this review article, we will review the anatomy of adductor canal, sonoanatomy, and ultrasound-guided approach for ACB as well as review current evidence regarding the indications of the ACB.

Cortical and vestibular stimulation reveal preserved descending motor pathways in individuals with motor-complete spinal cord injury.

OBJECTIVE: To use a combination of electrophysiological techniques to determine the extent of preserved muscle activity below the clinically-defined level of motor-complete spinal cord injury. METHODS: Transcranial magnetic stimulation and vestibular-evoked myogenic potentials were used to investigate whether there was any preserved muscle activity in trunk, hip and leg muscles of 16 individuals with motor-complete spinal cord injury (C4-T12) and 16 able-bodied matched controls. RESULTS: Most individuals (14/16) with motor-complete spinal cord injury were found to have transcranial magnetic stimulation evoked, and/or voluntary evoked muscle activity in muscles innervated below the clinically classified lesion level. In most cases voluntary muscle activation was accompanied by a present transcranial magnetic stimulation response. Furthermore, motor-evoked potentials to transcranial magnetic stimulation could be observed in muscles that could not be voluntarily activated. Vestibular-evoked myogenic potentials responses were also observed in a small number of subjects, indicating the potential preservation of other descending pathways. CONCLUSION: These results highlight the importance of using multiple electrophysiological techniques to assist in determining the potential preservation of muscle activity below the clinically-defined level of injury in individuals with a motor-complete spinal cord injury. These techniques may provide clinicians with more accurate information about the state of various motor pathways, and could offer a method to more accurately target rehabilitation.

Neurovascular structures at risk during anterolateral and medial arthroscopic approaches of the hip / Estructuras neurovasculares en riesgo durante abordajes artroscopicos anterolaterales y mediales de la cadera

To describe the safety areas for placement of 5 anterolateral portals (anterior, anterior lateral, posterior lateral, proximal anterior medial and distal anterior medial portals) and 3 recently described medial portals (anterior medial, posterior medial and distal posterior medial portals) to provide topographical description of the safety of each. A descriptive, observational and cross-sectional study in which femoral triangle dissection was performed in 12 hips. 5 lateral portals and the 3 medial portals were placed. Clinically relevant neurovascular structures associated with each portal, were identified measured and documented. The lateral portal with the highest risk of injury to a nearby neurovascular structure was the anterior portal, the most adjacent to the femoral cutaneous nerve, 1.42 cm (±0.85) lateral to the portal. In the medial portals, the anterior medial portal has the narrowest margin in relation to the femoral artery, 2.14 cm (±0.35) lateral to the portal and medial to the obturator nerve by 0.87 cm (±0.62). The lateral portals have a higher safety margin; the portal with the most proximity to a neurovascular structure is the anterior portal, associated laterally with the femoral cutaneous nerve, presenting a higher risk of injury. Medial portals have a higher risk of injuring the femoral neurovascular bundle as well as the obturator nerve.

El objetivo fue describir las áreas de seguridad para la colocación de 5 portales estándar (portal anterior, anterolateral, posterolateral, portal anterior proximal medial y portal anterior distal medial) y 3 portales mediales emergentes (antero medial, portal posteromedial y posteromedial distal) para proporcionar una descripción topográfica de la seguridad de cada portal. Se realizó un estudio descriptivo, observacional y transversal, en la que se disecó el triángulo femoral de 12 caderas. Se colocaron los 5 portales laterales y los 3 portales mediales. Se documentó la medición de cada estructura neurovascular de relevancia clínica en relación a cada uno de los portales evaluados. En cuanto al portal de mayor riesgo entre los laterales, se encontró el portal anterior con mayor cercanía al nervio cutáneo femoral lateral (1,42±0,85 cm), ubicado lateral al portal. En los portales mediales el portal anterior medial tiene el margen más estrecho respecto a la arteria femoral (2,14±0,35 cm) lateral al portal, y medial el nervio obturador (0,87±0,62 cm). Los portales laterales tienen un amplio margen de seguridad, el portal con el margen más reducido es el portal anterior en relación al nervio cutáneo femoral lateral, presentando un elevado riesgo de lesionarlo, los portales mediales tienen un alto riesgo de lesionar las estructuras neurovasculares femorales y el nervio obturador.

Modular organization of the multipartite central pattern generator for turtle rostral scratch: knee-related interneurons during deletions.

Central pattern generators (CPGs) are neuronal networks in the spinal cord that generate rhythmic patterns of motor activity in the absence of movement-related sensory feedback. For many vertebrate rhythmic behaviors, CPGs generate normal patterns of motor neuron activities as well as variations of the normal patterns, termed deletions, in which bursts in one or more motor nerves are absent from one or more cycles of the rhythm. Prior work with hip-extensor deletions during turtle rostral scratch supports hypotheses of hip-extensor interneurons in a hip-extensor module and of hip-flexor interneurons in a hip-flexor module. We present here single-unit interneuronal recording data that support hypotheses of knee-extensor interneurons in a knee-extensor module and of knee-flexor interneurons in a knee-flexor module. Members of knee-related modules are not members of hip-related modules and vice versa. These results in turtle provide experimental support at the single-unit interneuronal level for the organizational concept that the rostral-scratch CPG for the turtle hindlimb is multipartite, that is, composed of more than two modules. This work, when combined with experimental and computational work in other vertebrates, does not support the classical view that the vertebrate limb CPG is bipartite with only two modules, one controlling all the flexors of the limb and the other controlling all the extensors of the limb. Instead, these results support the general principle that spinal CPGs are multipartite.

Análise da eficácia da mobilização neural do nervo isquiático sobre ganho de ADM / Analysis of the efficacy of neural mobilization of the sciatic nerve in improving ROM

Introdução: A mobilização neural (MN) vem sendo utilizada para restaurar o movimento e a elasticidade do sistema nervoso. Objetivo: Avaliar o efeito imediato da MN do nervo isquiático sobre o ganho de amplitude de movimento (ADM) de flexão de quadril em indivíduos neurologicamente assintomáticos. Método: A amostra foi composta por 50 indivíduos, divididos em dois grupos. No Grupo 1, realizou-se avaliação da amplitude do membro direito, em seguida, executaram-se aplicação da técnica de MN e reavaliação da ADM também no referido membro. No Grupo 2, efetuaram-se avaliação do membro direito, aplicação da técnica de MN no esquerdo e reavaliação da ADM no direito. Resultados: Pôde-se observar que a média de ADM nos dois grupos apresentou aumento significativo, e o grupo da mobilização indireta obteve maior resultado. Conclusão: A MN do nervo isquiático demonstrou ser uma técnica eficaz para o ganho de ADM de flexão do quadril em indivíduos assintomáticos.

Introduction: Neural Mobilization (NM) has been used to restore movement and elasticity of the nervous system. Objective: To evaluate the immediate effect of NM of the sciatic nerve on the gain of range of motion (ROM) in hip flexion in neurologically asymptomatic individuals. Method: The sample consisted of 50 individuals, divided into two groups. In Group 1, we assessed the range of the right limb, applied the NM technique, and re-evaluated the same limb. In Group 2, we assessed the right limb, applied the NM technique on the left limb, and re-evaluated the ROM of the right one. Results: We observed that mean ROM in both groups experienced a significant increase, and that the indirect mobilization group had the best result. Conclusion: NM of the sciatic nerve was an effective technique for obtaining improvement in hip flexion ROM in asymptomatic individuals.

Limitations of the Vastus Lateralis Muscle as a Substitute for Lost Abductor Muscle Function: An Anatomical Study.

Abductor insufficiency after hip arthroplasty resulting from an impaired gluteus medius and minimus remains an unsolved problem in orthopaedic surgery. The vastus lateralis (VL) was described as a functional substitute for abductor insufficiency in 2004. We carried out a macrodissection of twelve cadaveric hemipelvises to investigate the innervation of the VL and adjacent muscles to assess the extent the VL can be safely transferred. Results showed that direct muscle branches to proximal portions of the VL are too short to allow a significant shift; the shift may be as small as 13 mm. Nerves that supply the VL also extend to the vastus intermedius. This innervation pattern makes it impossible to shift the VL significantly without damaging branches to both.

[The plasty for the hip region sores, using the flap, consisting of M. tensor fasciae latae].

The method of plasty for the hip region sores, based on transposition of proximal part of m. tensor fascia latae in content of the flap, using her transsection between place of attachment to spina iliaca anterior superior and place of the main vascular pedicle entry into the muscle, was proposed, what permits to prevent vast mobilization of the muscle and to secure existing in normal conditions and formed in pathological conditions anas- tomoses between vascular net of the flap and surrounding tissues. The method proposed was successfully applied for plasty of the hip region sores of degrees III-IV in 2 patients.

Reducing the risk of nerve injury during Bernese periacetabular osteotomy: a cadaveric study.

The modified Smith-Petersen and Kocher-Langenbeck approaches were used to expose the lateral cutaneous nerve of the thigh and the femoral, obturator and sciatic nerves in order to study the risk of injury to these structures during the dissection, osteotomy, and acetabular reorientation stages of a Bernese peri-acetabular osteotomy. Injury of the lateral cutaneous nerve of thigh was less likely to occur if an osteotomy of the anterior superior iliac spine had been carried out before exposing the hip. The obturator nerve was likely to be injured during unprotected osteotomy of the pubis if the far cortex was penetrated by > 5 mm. This could be avoided by inclining the osteotome 45° medially and performing the osteotomy at least 2 cm medial to the iliopectineal eminence. The sciatic nerve could be injured during the first and last stages of the osteotomy if the osteotome perforated the lateral cortex of ischium and the ilio-ischial junction by > 10 mm. The femoral nerve could be stretched or entrapped during osteotomy of the pubis if there was significant rotational or linear displacement of the acetabulum. Anterior or medial displacement of < 2 cm and lateral tilt (retroversion) of < 30° were safe margins. The combination of retroversion and anterior displacement could increase tension on the nerve. Strict observation of anatomical details, proper handling of the osteotomes and careful manipulation of the acetabular fragment reduce the neurological complications of Bernese peri-acetabular osteotomy.