Variations of the extrapsoas course of the lumbar plexus with implications for the lateral transpsoas approach to the lumbar spine: a cadaveric study.

BACKGROUND: Together with an increased interest in minimally invasive lateral transpsoas approach to the lumbar spine goes a demand for detailed anatomical descriptions of the lumbar plexus. Although definitions of safe zones and essential descriptions of topographical anatomy have been presented in several studies, the existing literature expects standard appearance of the neural structures. Therefore, the aim of this study was to investigate the variability of the extrapsoas portion of the lumbar plexus in regard to the lateral transpsoas approach. METHODS: A total of 260 lumbar regions from embalmed cadavers were utilized in this study. The specimens were dissected as per protocol and all nerves from the lumbar plexus were morphologically evaluated. RESULTS: The most common variation of the iliohypogastric and ilioinguinal nerves was fusion of these two nerves (9.6%). Nearly in the half of the cases (48.1%) the genitofemoral nerve left the psoas major muscle already divided into the femoral and genital branches. The lateral femoral cutaneous nerve was the least variable one as it resembled its normal morphology in 95.0% of cases. Regarding the variant origins of the femoral nerve, there was a low formation outside the psoas major muscle in 3.8% of cases. The obturator nerve was not variable at its emergence point but frequently branched (40.4%) before entering the obturator canal. In addition to the proper femoral and obturator nerves, accessory nerves were present in 12.3% and 9.2% of cases, respectively. CONCLUSION: Nerves of the lumbar plexus frequently show atypical anatomy outside the psoas major muscle. The presented study provides a compendious information source of the possibly encountered neural variations during retroperitoneal access to different segments of the lumbar spine.

Selective Repair of Motor Branches in the Femoral Nerve by Transferring the Motor Branches of Obturator Nerve: An Anatomical Feasibility Study.

BACKGROUND: Anterior branch of the obturator nerve transfer has been proven as an effective method for femoral nerve injuries, but the patient still has difficulty in rising and squatting, up and downstairs. Here, we presented a novel neurotization procedure of selectively repairing 3 motor branches of the femoral nerve by transferring motor branches of the obturator nerve in the thigh level and assessing its anatomical feasibility. METHODS: Eight adult cadavers (16 thighs) were dissected. The nerve overlap distance between the gracilis branch and the rectus femoris (RF) branch, the adductor longus (AL) branch and the vastus medialis (VM) branch, as well as the adductor magnus (AM) branch and the vastus intermedius (VI) branch were measured. Also, the axon counts of the donor and recipient nerve were evaluated by histological evaluation. RESULTS: In all specimens, nerve overlap of at least 2.1 cm was observed in all 16 dissected thighs between the donor and recipient nerve branches, and the repair appeared to be without tension. There is no significant difference in the axon counts between gracilis branch (598 ± 83) and the RF branch (709 ± 151). The axon counts of the AL branch (601 ± 93) was about half of axon counts of the VM branch (1423 ± 189), and the axon counts of AM branch (761 ± 110) was also about half of the VI branch (1649 ± 281). CONCLUSIONS: This novel technique of the combined nerve transfers below the inguinal ligament, specifically the gracilis branch to the RF branch, the AL branch to the VM branch, and the AM branch to the VI branch, is anatomically feasible. It provides a promising alternative in the repair of femoral nerve injuries and an anatomical basis for the clinical application of motor branches of the obturator nerve transfer to repair the motor portion of the injured femoral nerve.

Variations of the obturator nerve and implications in obturator nerve entrapment treatment: an anatomical study.

INTRODUCTION: Obturator nerve entrapment or idiopathic obturator neuralgia is an unfamiliar pathology for many physicians which can lead to diagnostic errancy. This study aims to identify the potential compression areas of the obturator nerve to improve therapeutic management. MATERIAL AND METHODS: 18 anatomical dissections of lower limbs from 9 anatomical cadavers were performed. Endopelvic and exopelvic surgical approaches were utilized to study the anatomical variations of the nerve and to identify areas of entrapment. RESULTS: On 7 limbs, the posterior branch of the obturator nerve passed through the external obturator muscle. A fascia between the adductor brevis and longus muscles was present in 9 of the 18 limbs. The anterior branch of the obturator nerve was highly adherent to the fascia in 6 cases. In 3 limbs, the medial femoral circumflex artery was in close connection with the posterior branch of the nerve. CONCLUSION: Idiopathic obturator neuropathy remains a difficult diagnosis. Our cadaveric study did not allow us to formally identify one or more potential anatomical entrapment zones. However, it allowed the identification of zones at risk. A clinical study with staged analgesic blocks would be necessary to identify an anatomical area of compression and would allow targeted surgical neurolysis.

Label-free histomorphometry of peripheral nerve by stimulated Raman spectroscopy.

BACKGROUND: Conventional processing of nerve for histomorphometry is resource-intensive, precluding use in intraoperative assessment of nerve quality during nerve transfer procedures. Stimulated Raman scattering (SRS) microscopy is a label-free technique that enables rapid and high-resolution histology. METHODS: Segments of healthy murine sciatic nerve, healthy human obturator nerve, and human cross-facial nerve autografts were imaged on a custom SRS microscope. Myelinated axon quantification was performed through segmentation using a random forest machine learning algorithm in commercial software. RESULTS: High contrast, high-resolution imaging of nerve morphology was obtained with SRS imaging. Automated myelinated axon quantification from cross-sections of healthy human nerve imaged using SRS was achieved. CONCLUSIONS: Herein, we demonstrate the use of a label-free technique for rapid imaging of murine and human peripheral nerve cryosections. We illustrate the potential of this technique to inform intraoperative decision-making through rapid automated quantification of myelinated axons using a machine learning algorithm.

Anatomical study of the masseteric and obturator nerves: Application to face transplant and reanimation procedures.

The masseteric nerve (MN) and the anterior branch of the obturator nerve (ON) that innervate the transferred gracilis muscle have proved highly efficient for reanimating paralyzed facial muscles when muscle transfer is required. Previous researchers have published the total axonal load for myelinated fibers in both nerves. However, the real motor axonal load has not been established. We performed the study on 20 MN and 13 ON. The segments of the MN and the ON were embedded in paraffin, sectioned at 10 µm, and stained following a standard immunohistochemical procedure using anti-choline acetyltransferase to visualize the motor fibers. The MN has a higher axonal load than the ON. There were statistically significant differences between the axonal load of the proximal segment of the MN and the ON. These findings confirm that end-to-end anastomoses between the MN and the ON should preferably use the proximal segment. However, MN neurotomy should ideally be performed between the proximal and distal segments, preserving innervation to the deep fascicles. Our results show that the MN is ideal as a donor motor nerve for reinnervating transplanted muscle for dynamic reanimation of the paralyzed face. The neurotomy should ideally be performed between the first and second collateral branches of the MN. Clin. Anat. 32:612-617, 2019. © 2019 Wiley Periodicals, Inc.

Distribution of sensory nerves supplying the knee joint capsule and implications for genicular blockade and radiofrequency ablation: an anatomical study.

BACKGROUND: Despite their emerging therapeutic relevance, there are many discrepancies in anatomical description and terminology of the articular nerves supplying the human knee capsule. This cadaveric study aimed to determine their origin, trajectory, relationship and landmarks for therapeutic purpose. METHODS: We dissected 21 lower limbs from 21 cadavers, to investigate the anatomical distribution of all the articular nerves supplying the knee joint capsule. We identified constant genicular nerves according to their anatomical landmarks at their entering point to knee capsule and inserted Kirschner wires through the nerves in underlying bone at those target points. Measurements were taken, and both antero-posterior and lateral radiographs were obtained. RESULTS: The nerve to vastus medialis, saphenous nerve, anterior branch of obturator nerve and a branch from sciatic nerve provide substantial innervation to the medial knee capsule and retinaculum. The sciatic nerve and the nerve to the vastus lateralis supply sensory innervation to the supero-lateral aspect of the knee joint while the fibular nerve supplies its infero-lateral quadrant. Tibial nerve and posterior branch of obturator nerve supply posterior aspect of knee capsule. According to our findings, five constant genicular nerves with accurate landmarks could be targeted for therapeutic purpose. CONCLUSION: The pattern of distribution of sensitive nerves supplying the knee joint capsule allows accurate and safe targeting of five constant genicular nerves for therapeutic purpose. This study provides robust anatomical foundations for genicular nerve blockade and radiofrequency ablation.

Cutaneous Branch of the Obturator Nerve Extending to the Medial Ankle and Foot: A Report of Two Cadaveric Cases.

The area of skin supplied by the cutaneous branch of the obturator nerve (CBO) is highly variable. Although most introductory anatomy texts describe the CBO as innervating only a portion of the medial thigh, there are numerous reports in the literature of CBOs passing the knee to innervate the proximal, middle, or even distal leg. There are no previous reports of CBOs extending to the ankle and foot. Herein we describe 2 cases of CBOs extending at least to the medial foot. Both cases were discovered incidentally, during routine cadaver dissections by osteopathic and podiatric medical students in the anatomy laboratory of Western University of Health Sciences in California. In both instances, the anomalously long CBOs shared several characteristics: (1) they arose as direct branches of the anterior division of the obturator nerve, not from the subsartorial plexus; (2) they coursed immediately posterior to the great saphenous vein from the distal thigh to the distal leg, only deviating away from the saphenous vein just above the medial malleolus; and (3) they terminated in radiating fibers to the posterior half of the medial ankle and foot. In both cases, the saphenous branch of the femoral nerve was present but restricted to the area anterior to the great saphenous vein. It is likely that the variant CBOs carried fibers of the L4 spinal nerve and thus provided cutaneous innervation to the medial foot and ankle, a function most commonly reserved for the saphenous branch of the femoral nerve distal to the knee. Saphenous neuropathy is a common postoperative complication of saphenous cutdowns for coronary artery bypass grafts, so the potential involvement of a long CBO can add additional complexity to regional anesthetic blocks for foot and ankle surgery and procedures such as vein harvesting for coronary artery bypass grafts.

Arthroscopic Reconstruction of the Ligamentum Teres: A Guide to Safe Tunnel Placement.

PURPOSE: To provide a quantitative guide to tunnel placement concurrently through the femur and acetabulum during a ligamentum teres reconstruction, minimizing the risk of injury to the obturator neurovascular bundle. METHODS: Nine human cadaveric pelvises, complete with femurs (mean age, 59.6 years; age range, 47-65 years), were studied. Before dissection, a 3-dimensional coordinate-measuring device was used to record the neutral orientation of the femur in the acetabulum. The specimens were then dissected free of all extra-articular soft tissue, except for the ligamentum teres and the obturator neurovascular bundle, and digitized. An anatomic femoral reconstruction tunnel through the femoral neck was simulated and extended along its axis into the acetabulum. The femur was digitally rotated internally from 0° to 30° and externally from 0° to 40°, as well as abducted from 0° to 30° and adducted from 0° to 20°, in increments of 1°. At each position, the location of the simulated acetabular reconstruction tunnel was measured with respect to the obturator bundle and the edge of the acetabular fossa. RESULTS: The anatomic reconstruction tunnel entered the lateral side of the femur at a mean distance of 7.0 mm distal and 5.8 mm anterior to the center of the vastus ridge. By angling the femur at 15° of internal rotation and 15° of abduction, the obturator neurovascular bundle was avoided in 100% of specimens. CONCLUSIONS: The most important finding of this study was that a ligamentum teres reconstruction tunnel could be reamed through the femoral neck and safely positioned in the acetabulum by angling the femur at 15° of internal rotation and 15° of abduction. CLINICAL RELEVANCE: These quantitative descriptions of the ligamentum teres reconstruction tunnels can be used to guide arthroscopic surgical interventions designed to address ligamentum teres pathology.

Anatomical study of the articular branches innervated the hip and knee joint with reference to mechanism of referral pain in hip joint disease patients.

INTRODUCTION: Referred pain in the anterior knee joint is the most common symptom in hip disease patients. The development of referred pain is considered to be related to dichotomizing peripheral sensory fibers. However, no gross anatomical findings identify any dichotomizing fibers innervating both the hip and knee joints. We dissected the femoral and obturator nerves in human cadavers to investigate the distribution of the articular branches in the hip and knee joints. Fourteen embalmed left lower limbs from 14 Japanese adult cadavers (five from females, nine from males, average age 73.8 ± 14.1 years) were observed macroscopically. The articular branches of the femoral and obturator nerves were dissected at the anterior margin of the groin toward the thigh region. After dissections of the articular nerves of the hip joints, the femoral and obturator nerves were exposed from proximally to distally to identify the articular nerves of the knee joints. The branching pattern of the articular branches in the hip and knee joints was recorded. In six of 14 limbs (42.9%), the femoral nerve supplied articular branches to the anteromedial aspect of both the hip and knee joints. These articular branches were derived from the same bundle of femoral nerve. These gross anatomical findings suggested that dichotomizing peripheral sensory fibers innervate the hip and knee joints and these could relate to the referred pain confirmed in the anterior knee joints of patients with hip disease. Clin. Anat. 31:705-709, 2018. © 2018 Wiley Periodicals, Inc.

Re-defining the anatomical structures for blocking the nerves in adductor canal and sciatic nerve through the same injection site: an anatomical study.

PURPOSE: The aim of this study is to re-define the anatomical structures which are important for blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site. We also aimed to investigate the spread of the anesthetic toward the areas in which the mentioned nerves lie on cadavers. METHODS: This study was performed on 16 lower extremities of formaldehyde-embalmed eight adult cadavers. The anatomy of adductor canal, courses of the nerves within the canal and the relationships of the saphenous, medial femoral cutaneous, medial retinacular, posterior branch of the obturator and sciatic nerves with each other and with the fascial compartments were investigated. Transverse sections that crossed the superior border of vastoadductor membrane were taken to reach the sciatic nerve in the shortest way. Colored latex was injected to demonstrate the anesthetic blockage of the targeted nerves. The structures along the needle's way were investigated. RESULTS: The saphenous, medial femoral cutaneous and at its distal part posterior branch of the obturator nerve were colored with latex within the adductor canal. The nerve to vastus medialis (in other words, the medial retinacular nerve) lay beneath the fascia of vastus medialis and did not enter the adductor canal. There was a fascial plane which did not allow the passage of colored latex toward the sciatic nerve. To traverse this fascial structure, it was found out to be necessary to insert the needle perpendicular to both the vertical and transverse axes of the thigh and then advance it along 2/3 of diameter of the thigh. Thus, the colored latex was observed to fill the compartment where the sciatic nerve lay within. CONCLUSIONS: Blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site seems anatomically possible without injuring any neurovascular structures.

Ultrasound-guided femoral and obturator nerves block in the psoas compartment in dogs: anatomical and randomized clinical study.

OBJECTIVE: To evaluate intraoperative and postoperative efficacy of ultrasound (US)-guided femoral (FN) and obturator (ON) nerves block, in the iliopsoas muscle compartment (IPM), using an in-plane technique. STUDY DESIGN: Anatomical research and randomized, prospective, 'blinded' clinical study. ANIMALS: Six dog cadavers and 20 client-owned dogs undergoing tibial plateau levelling osteotomy (TPLO) surgery. METHODS: In phase 1, anatomical dissections and US imaging of the IPM were performed to design an US-guided nerve block involving the FN and ON simultaneously. The technique was considered successful if new methylene blue solution injection (0.1 mL kg-1) stained FN-ON for ≥2 cm. In phase 2, the US-guided nerve block designed in phase 1, combined with US-guided sciatic nerve (ScN) block, was performed in 20 dogs undergoing TPLO surgery. Patients were assigned randomly to one of two treatment groups: ropivacaine 0.3% (R3, n=10) and ropivacaine 0.5% (R5, n=10) at a volume of 0.1 mL kg-1 for each nerve block. Intraoperative success rate (fentanyl requirement < 2.1 mcg kg-1 hour-1) and postoperative pain score [Short Form-Glasgow Composite Measure Pain Scale (SF-GCMPS) ≥ 5/20] were evaluated. RESULTS: In phase 1, the US image of FN-ON was detected between L6 and L7. In-plane needling technique produced a staining of >4 cm in six of six cases. No abdominal or epidural dye spread was found. In phase 2, median fentanyl infusion rates were 0.5 (0.0-0.9) µg kg-1 hour-1 for R3 and 0.6 (0.0-2.2) µg kg-1 hour-1 for R5. At 9 and 11 hours after the peripheral nerve blocks, an SF-GCMPS ≥ 5 was observed for R3 and R5, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The US-guided FN-ON block in the IPM, using an in-plane technique, combined with US-guided ScN block, provided sufficient analgesia to minimize the use of fentanyl during TPLO surgery. A longer postoperative analgesia was observed in group R5 compared with R3.

Topographical relationships between the obturator nerve, artery, and vein in the lateral pelvic wall.

INTRODUCTION AND HYPOTHESIS: The aims of this study were to determine the topographical relationships between the obturator nerve (ON), artery (OA), and vein (OV) in the lateral pelvic wall. METHODS: One hundred and fifty hemipelvises of 84 Korean cadavers were dissected. RESULTS: The ON, OA, and OV ran in that order (from upper to lower) within the lateral pelvic wall in 46.7 % of specimens. In 32 % of cases, the three structures were separated at the posterior portion of the wall and then converged toward the obturator canal (OC). In 10 %, the OA and OV were in contact with each other and separate from the ON; in 2 %, the ON was contiguous with the OA and separate from the OV; in 2.7 %, all three structures were in contact with each another. Alternately, the order of ON, OA, and OV was altered in the lateral pelvic wall in 41.3 % of specimens. Finally, in 12 % specimens, either the OA or OV or both were absent from the lateral pelvic wall. CONCLUSIONS: The possibility of the presence of either the OA or OV being between the ON and the external iliac vein, and the potential contact between the ON and either the OA or OV in the lateral pelvic wall, should be borne in mind during pelvic procedures.

Anatomical feasibility of the anterior obturator nerve transfer to restore bowel and bladder function.

Total sacrectomies are radical procedures required to treat tumorigenic processes involving the sacrum. The purpose of our anatomical study was to assess the feasibility of a novel nerve transfer involving the anterior obturator nerve to the pudendal and pelvic nerves to the rectum and bladder. Anterior dissection of the obturator nerve was performed in eight hemipelvis cadaver specimens. The common obturator nerve branched into the anterior and posterior at the level of the obturator foramen. The anterior branch then divided into two separate branches (adductor longus and gracilis). The branch to the gracilis was on average longer and also larger than the branch to the adductor longus (8.7 ± 2.1 cm vs. 6.7 ± 2.6 cm in length and 2.6 ± 0.2 mm vs 1.8 ± 0.4 mm in diameter). Each branch of the anterior obturator was long enough to reach the pelvic nerves. The novel transfer of the anterior branch of the obturator nerve to reinnervate the bladder and bowel is anatomically feasible. This represents a promising option with minimal donor site deficit.

The adductor part of the adductor magnus is innervated by both obturator and sciatic nerves.

The hip adductor group, innervated predominantly by the obturator nerve, occupies a large volume of the lower limb. However, case reports of patients with obturator nerve palsy or denervation have described no more than minimal gait disturbance. Those facts are surprising, given the architectural characteristics of the hip adductors. Our aim was to investigate which regions of the adductor magnus are innervated by the obturator nerve and by which sciatic nerve and to consider the clinical implications. Twenty-one lower limbs were examined from 21 formalin-fixed cadavers, 18 males and 3 females. The adductor magnus was dissected and was divided into four parts (AM1-AM4) based on the locations of the perforating arteries and the adductor hiatus. AM1 was supplied solely by the obturator nerve. AM2, AM3, and AM4 received innervation from both the posterior branch of the obturator nerve and the tibial nerve portion of the sciatic nerve in 2 (9.5%), 20 (95.2%), and 6 (28.6%) of the cadavers, respectively. The double innervation in more than 90% of the AM3s is especially noteworthy. Generally, AM1-AM3 corresponds to the adductor part, traditionally characterized as innervated by the obturator nerve, and AM4 corresponds to the hamstrings part, innervated by the sciatic nerve. Here, we showed that the sciatic nerve supplies not only the hamstrings part but also the adductor part. These two nerves spread more widely than has generally been believed, which could have practical implications for the assessment and treatment of motor disability.

Anatomical feasibility of transferring the obturator and genitofemoral nerves to repair lumbosacral plexus nerve root avulsion injuries.

Nerve transfer is a valid surgical procedure for restoring lower-extremity function after lumbosacral plexus nerve root avulsion. We determined the anatomical feasibility of transferring the obturator and genitofemoral nerves for this purpose. The obturator, genitofemoral and femoral nerves, and the S1 and S2 nerve roots on both sides were exposed in 10 cadaver specimens. We traced all nerves to their origins. The lengths of the obturator and genitofemoral nerves were measured from their origins to their exits from the abdominal cavity. The transverse and longitudinal diameters of all nerves were measured. Specimens were obtained to determine the total number of myelinated fibers in each nerve. The proximal part of the left obturator nerve was anastomosed with the distal part of the right femoral nerve, between the vertebrae and the peritoneum, with an overlap of 2-3 cm. Similarly, the proximal parts of the right obturator and genitofemoral nerves were anastomosed with the ipsilateral S1 and S2 nerve roots, respectively, with an overlap of 2-4 cm. The obturator nerve contained approximately one-third of the number of fibers (4,300-7,800) presenting in the femoral nerve (13,500-21,000). Similarly, the number of fibers found in the S1 nerve root was in the range 5,200-8,900. The genitofemoral nerve contained approximately half the number of fibers (3,000-4,500) presenting in the S2 nerve root (4,600-8,400). The obturator and genitofemoral nerves could be suitable donor nerves for repairing lumbosacral plexus nerve root avulsion.

Femoral and obturator neuropathies.

The femoral and obturator nerves both arise from the L2, L3, and L4 spinal nerve roots and descend into the pelvis before emerging in the lower limbs. The femoral nerve's primary function is knee extension and hip flexion, along with some sensory innervation to the leg. The obturator nerve's primary function is thigh adduction and sensory innervation to a small area of the medial thigh. Each may be injured by a variety of potential causes, many of them iatrogenic. Here, we review the anatomy of the femoral and obturator nerves and the clinical features and potential etiologies of femoral and obturator neuropathies. Their necessary investigations, including electrodiagnostic studies and imaging, their prognosis, and potential treatments, are discussed in this chapter.

Fixation of the Ajust minisling based upon cadaveric study.

INTRODUCTION AND HYPOTHESIS: The objective was to describe the fixation site of the anchor of the Ajust mid-urethral minisling. METHODS: This cadaveric study was based on a group of 11 formalin-embalmed bodies with legs positioned in 30° flexion and 30° abduction, and a group of five fresh-frozen bodies with legs positioned as normal during the procedure. The groups were later compared. The fixation site was dissected and described. The distance to the obturator bundle was considered as the primary safety parameter. To compare the groups of fresh-frozen bodies and formalin-embalmed bodies, the Student's t test and Mann-Whitney test were used. RESULTS: In the group of formalin-embalmed bodies the mean distance from the anchoring device to the obturator nerve was 4.23 cm. In 19 cases out of 22 the anchor was within the complex of the obturator membrane and obturator muscles. In the group of fresh frozen bodies the mean distance to the obturator nerve was 3.15 cm. In 9 cases out of 10 the anchor was in the complex of the obturator membrane and obturator muscles. CONCLUSION: The distance from the anchor to the obturator nerve was more than 2 cm in all cases. Correct placement in the obturator membrane was achieved in 65.6 % of cases. In 87.5 % of cases the anchor was placed within the complex of obturator membrane and obturator muscles.

[The conflict between obturator nerve and ovary: a cadaveric and radioanatomic study]. / Le conflit ovaro-obturateur : une étude cadavérique et radio-anatomique.

The aim of this study was to describe the anatomical relationships between the ovary and the obturator nerve in its intrapelvic portion. Seven embalmed cadavers were dissected; 20 MRIs were then analyzed. The main distance between the lateral pole of the ovary and the obturator nerve was 29 mm. The authors describe various etiologies responsible for obturator neuralgia. An underdiagnosed cause is gonadal hypertrophy.

Morphology and morphometry of the human obturator nerve in males and females.

Peripheral nerve injury and the nerves' subsequent repair and regeneration continues to be marked clinically by poor functional recovery. The analysis of nerve morphology is an aspect which may provide an impact on successful clinical outcomes through better prediction of donor and recipient matching. In this study, we evaluated the morphological aspects of the human obturator nerve for a better understanding of its potential in nerve transplantation. Morphological characteristics of donor obturator nerves were analysed, including nerve diameter and length, fascicle count and the ratio of neural to non-neural tissue present within the cross-sectional area of the nerve's epineurium, with respect to laterality and sex. Statistical significance (p < 0.10) was determined for male obturator nerves having an average diameter of 2.67 mm compared to female obturator nerves at 1.91 mm, as well as left obturator nerves having an average of 11.21 fascicles compared to the right having an average of 10.17 fascicles. Strong positive correlations were determined between cross-sectional nerve area and limb size index, as well as between percentage of non-neural tissue and area of non-neural tissue, among males. Separately, strong correlation between percentage of non-neural tissue and area of non-neural tissue among right obturator nerves in males and females was determined . These findings indicate that there are associations and predictions that can be made about nerve morphology and that these when combined with other patient characteristics may enhance patient functional recovery following a peripheral nerve's repair.

Revisiting the Muscular Innervation of the Obturator Nerve: Application to Neurotization Procedures.

BACKGROUND: Our goal was to revisit the innervation of the adductor muscles of the thigh and add new evidence to currently existing knowledge. METHODS: Ten thighs from five fresh frozen cadavers were dissected. Obturator nerve innervation to the pectineus, obturator externus, adductor brevis, adductor magnus, adductor longus, and gracilis was documented. RESULTS: The adductor longus and gracilis were innervated by the anterior branch in 100%, and the adductor magnus was innervated by the posterior branch in 100%. The adductor brevis was supplied by both the anterior and posterior branches in 90%. The obturator externus was innervated by the posterior branch in 60% and a direct branch from the main trunk in 10%. No innervation of the obturator externus by the obturator nerve was found in 30%. CONCLUSIONS: The obturator externus and adductor brevis need to be explored further to clarify their innervation.