The median nerve´s system of connective tissue distal to the pronator teres to the carpal tunnel.

BACKGROUND: Connective tissue serves a role beyond mere spatial filling. Furthermore, there is increasing evidence that connective tissue plays an important role in the pathogenesis of conditions such as carpal tunnel syndrome (CTS). According to our hypothesis, the median nerve (MN) is surrounded by a system of connective tissue distal to the pronator teres and extending up to, and including, the carpal tunnel. METHODS: To visualize the connective tissue surrounding the median nerve, we dissected the forearms of 15 body donors from pronator teres to the carpal tunnel, created plastination slices stained with Periodic Acid-Schiff (PAS), and injected ink into the seen spaces. We verified our findings with a segmentational analysis of radiological data of 10 healthy individuals. RESULTS: We macroscopically describe the median nerve´s system of connective tissue (MC) distal to the pronator teres and up to and including the carpal tunnel. This system creates, connects, and separates spaces. At least from the pronator teres to the carpal tunnel it also creates subspaces from proximal to distal. For the MC, we established a mean cross-sectional area of 153.1 mm2 (SD=37.15) in the carpal tunnel. The median nerve consistently resides at the center of this MC, which further connects to flexor muscles of the forearm, and to the radius bone. In the carpal tunnel, the MC creates subspaces inside. There, it also acts as the outermost internal layer enveloping flexor tendons, and the MN. DISCUSSION: The term MC does not negate but orders the existence of other "connectives", like subsynovial connective tissue, endo-, epi- or perineuria, epimysia, periostea, or peritendinea, to a hierarchy related to the median nerve. Diseases of the MN are common. Knowing the anatomy of the MC and how it relates to MN function may help clinicians recognize and understand conditions like CTS.

Presenting embryologically defined peripancreatic compartments and fusion planes in the search for pancreatic cancer fields.

BACKGROUND: Clinical progress in form of "total mesometrial resection" (TMMR) in cervical cancer and "total mesorectal excision" (TME) in rectal cancer can be traced to a paradigm-shift regarding the extent and range of resection. More significance is bestowed upon embryologically defined borders which define compartments, "morphogenetic units" and "cancer fields", that have to be addressed in order to avoid incomplete tumor resection. We want to transfer this rationale on the pancreas and define such borders for pancreatic compartments. MATERIAL AND METHODS: We used 26 unfixed body donors (16 male, 10 female) ranging in age from 64 to 98 years. Manual preparation consisted of performing the Cattell-Braasch maneuver to restore embryologic anatomy and define fascial remnants of the borders of the dorsal and ventral mesogastrium with focus on the pancreatic fusion fasciae and peripancreatic spaces. RESULTS: We tracked what used to be the dorsal and ventral mesogastrium and assigned their remnants to the bowel and pancreas. Following avascular embryologic fascial fusion planes along the mesogastria we could demonstrate peripancreatic spaces, which were sealed off from bordering surfaces of presumably different morphogenetic units and possible cancer fields. Reverting embryologic development also seemed possible within the pancreas, demonstrating the embryologic fusion plane between the ventral and dorsal pancreatic buds as two distinct compartments. CONCLUSIONS: Following pancreatic fusion fasciae by separating embryologic fusion planes enables to define the pancreatic compartments which might play a major role in applying the success of TMMR and TME on pancreatic resection and define pancreatic cancer fields.

Drying irreversibly affects the elastic behavior of pelvic cortical bone.

Various studies have shown that the water content affects the elastic behavior of cortical bone. However, there is disagreement regarding the reversibility of the elastic behavior with rewetting. This study investigates this issue using an intrinsic approach, i.e., moisture manipulation and material testing were always carried out on the same specimen. The test results were then evaluated separately for each of several specimens. In total, 24 specimens of human cortical bone from the ischiopubic ramus were examined. The water content was varied in 11 steps, and the corresponding elastic moduli were determined using three-point bending tests within the elastic range. Moisture adjustment was achieved mainly using desiccators, accelerated by forced convection. Reference samples stored in the same manner were evaluated microscopically. The experiments confirmed the known correlation between water content reduction and stiffness increase of cortical bone. Complete drying increased the elastic modulus by about 83 %. By rewetting, the stiffness was significantly reduced again, though not only to the initial state, but even about 24 % below this. Thus, an irreversible alteration of the elastic behavior was observed. Decay of the reference samples was not observed. Therefore, decay is not the main reason for the significant loss of stiffness. In terms of the storage conditions for cortical bone specimens, an environment with 100 % relative humidity yielded the best match with the initial state. This storage method can therefore be recommended for biomechanical specimens used to determine in-vivo-like material parameters.

On a potential morpho-mechanical link between the gluteus maximus muscle and pelvic floor tissues.

Stress urinary incontinence presents a condition not only found in female elderlies, but also in young athletes participating in high-impact sports such as volleyball or trampolining. Repeated jumps appear to be a predisposing factor. Yet the pathophysiology remains incompletely elucidated to date; especially with regard to the influence of the surrounding buttock tissues including gluteus maximus. The present study assessed the morpho-mechanical link between gluteus maximus and the pelvic floor female bodies. 25 pelves obtained from Thiel embalmed females were studied in a supine position. Strands of tissues connecting gluteus maximus with the pelvic floor obtained from 20 sides were assessed mechanically. Plastinates were evaluated to verify the dissection findings. In total, 49 hemipelves were included for data acquisition. The fascia of gluteus maximus yielded connections to the subcutaneous tissues, the fascia of the external anal sphincter and that of obturator internus and to the fascia of the urogenital diaphragm. The connection between gluteus maximus and the urogenital diaphragm withstood an average force of 23.6 ± 17.3 N. Cramér φ analyses demonstrated that the connections of the fasciae connecting gluteus maximus with its surroundings were consistent in the horizontal and sagittal planes, respectively. In conclusion, gluteus maximus is morphologically densely linked to the pelvic floor via strands of connective tissues investing the adjacent muscles. Though gluteus maximus has also been reported to facilitate urinary continence, the here presented morpho-mechanical link suggests that it may also have the potential to contribute to urinary stress incontinence. Future research combining clinical imaging with in-situ testing may help substantiate the potential influence from a clinical perspective.

Diffusion tensor imaging: Influence of segmentation on fiber tracking in the supraspinatus muscle-An inter-operator reliability analysis.

The ability of muscle to generate force depends on its architecture and health condition. MR-based diffusion tensor imaging of muscle (mDTI) is an innovative approach for showing the fiber arrangement for the whole muscle volume. For accurate calculations of fiber metrics, muscle segmentation prior to tractography is regarded as necessary. Since segmentation is known to be operator dependent, it is important to understand how segmentation affects tractography. The aim of this study was to compare the results of deterministic fiber tracking based on muscle models generated by two independent operators. In addition, this study compares the results with a segmentation-free approach. Fifteen subjects underwent mDTI of the right shoulder. The results showed that mDTI can be successfully applied to complex joints such as the human shoulder. Furthermore, operator segmentation did not influence the results of fiber tracking and fascicle length (FL), fiber volume (FV), fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) showed excellent intraclass correlation estimates (≥ 0.975). As an exploratory approach, the segmentation-free fiber tracking showed significant differences in terms of mean fascicle length. Based on these findings, we conclude that tractography is not sensitive to small deviations in muscle segmentation. Furthermore, it implies that mDTI and automatic segmentation approaches or even a segmentation-free analysis can be considered for evaluation of muscle architecture.

Approach to standardized material characterization of the human lumbopelvic system-Specification, preparation and storage.

The complexity of the osseo-ligamentous lumbopelvic system has made it difficult to perform both, the overall preparation as well as specimen harvesting and material testing with a reasonable amount of time and personnel. The logistics of such studies present a hurdle for reproducibility. A structured procedure was developed and proved, which allows all necessary steps to be carried out reproducibly and in a reasonable time. This enables the extraction of 26 soft tissue, 33 trabecular and 32 cortical bone specimens from this anatomical region per cadaver. The integrity of the specimens remains maintained while keeping requirements within manageable limits. The practicability of the intended five-day specimen harvesting and testing procedure could be demonstrated on five test and two pre-test sequences. The intended minimization of physical, biological, and chemical external influences on specimens could be achieved. All protocols, instructions and models of preparation and storage devices are included in the supporting information. The high grade of applicability and reproducibility will lead to better comparability between different biomechanical investigations. This procedure proven on the human pelvis is transferable to other anatomical regions.

Synovium and blood capillaries at the femoral attachment of anterior cruciate ligament are significantly abundant than those at the tibial attachment / Sinovial y capilares sanguíneos en la inserción femoral del ligamento cruzado anterior son significativamente más abundantes que los de la inserción tibial

SUMMARY: The anterior cruciate ligament (ACL) is a ligament that mainly controls the anterior and rotational mobility of the knee joint, and its surface is covered by a synovial membrane with large number of blood vessels. In general, nutritional supply to the ligament is from many capillaries in the adjacent synovium. However, statistical studies of the capillaries distributed to the ACL are insufficient. In this study, we examined cross-sectional histological images of the femoral attachment (femoral level), middle level of the tendon (middle level), and tibial attachment (tibial level) of the ACL and statistically analyzed blood capillary distribution among the three levels. The ACLs of 10 cadavers were divided into 5 equal sections, and 4mm-thick paraffin sections were made at the femoral level, middle level, and tibial level, and then hematoxylin-eosin (HE) staining were performed. The area of each transverse section was measured using Image-J 1.51n (U. S. National Institutes of Health, Bethesda, MD, USA). Fiber bundles of the ACL were relatively small and sparse in cross-sectional area at the femoral level and became larger and denser toward the tibial level. Many blood levels. The synovium at the attachment of ACL covered the surface of the fiber bundle and also penetrated deeply between the fiber bundles. In particular, the blood capillaries were densely distributed in the synovium at the femoral attachment rather than another two levels. Indeed, the number of capillaries were also most abundant in the femoral level. The cross-sectional ACL area at the femoral level is significantly small, however, the blood capillaries were most abundant. Therefore, when the ACL is injured, its reconstruction with preservation of the femoral ligamentous remnant may be clinically useful for remodeling of the grafted tendon.

El ligamento cruzado anterior (LCA) es un ligamento que controla principalmente la movilidad anterior y rotacional de la articulación de la rodilla, y su superficie está cubierta por una membrana sinovial con gran cantidad de vasos sanguíneos. En general, el suministro de nutrientes al ligamento proviene de muchos capilares en la sinovial adyacente. Sin embargo, los estudios estadísticos de los capilares distribuidos en el LCA son insuficientes. En este estudio, examinamos imágenes histológicas trans- versales de la inserción femoral (nivel femoral), el nivel medio del tendón (nivel medio) y la inserción tibial (nivel tibial) del LCA y analizamos estadísticamente la distribución de los capilares sanguíneos entre los tres niveles. Los LCA de 10 cadáveres se dividieron en 5 secciones iguales y se realizaron cortes en parafina de 4 µm de espesor a nivel femoral, medio y tibial, y luego se realizó tinción con hematoxilina-eosina (HE). El área de cada sección transversal se midió utilizando Image-J 1.51n (Institutos Nacionales de Salud de EE. UU., Bethesda, MD, EE. UU.). Los haces de fibras del LCA eran relativamente pequeños y escasos en el área de la sección transversal a nivel femoral y se hicieron más grandes y más densos hacia el nivel tibial. La membrana sinovial en la unión del LCA cubría la superficie del haz de fibras y también penetraba profundamente entre entre los haces de fibras. En particular, los capilares sanguíneos estaban densamente distribuidos en la unión femoral de la sinovial respecto a los otros dos niveles. De hecho, el número de capilares también fue más abundante a nivel femoral. El área transversal del LCA a nivel femoral era significativamente pequeña, sin embargo, los capilares sanguíneos fueron los más abundantes. Por lo tanto, cuando hay una lesión del LCA su reconstrucción con preservación del ligamento femoral remanente puede ser clínicamente útil para remodelar el tendón injertado.

The subpopliteal fat body.

INTRODUCTION: The knee is likely to get hurt due to its excessive weight-bearing, for which it is surrounded by strongly tensioned ligaments, connectives and muscles. These highly active structures are imbedded in fatty tissue. The Fatty and loose connective tissue of the knee recently gained a renaissance in research. While the Hoffa fat body in the ventral knee attracted attention over the last years, we have investigated a smaller, dorsal fat body, ventral to the popliteus muscle. This fat body has not been described before. MATERIALS AND METHODS: 11 knees of 11 fresh specimens were investigated. All muscles but the popliteus muscle were removed. The popliteus was released from its tibial origin and dissected towards its tendinous insertion. Thereby, a subpopliteal fat body (SFB) was shown. The related vessels and nerves were evaluated. The size of the body was measured. Examples of histological slices were stained with HE and immunostained against neurofilament. RESULTS: The SFB lies ventral of the popliteus muscle at the concave posterior tibia and attaches to the periosteum and the popliteus muscle. It is not attached to the posterior cruciate ligament. It is separated from the subpopliteal recess by a lamella deriving from the fibular head. Arterial and venous vessels are seen entering the SFB, deriving from the popliteal artery or the anterior tibial artery. A subbranch of the tibial nerve was seen to reach the SFB. The SFB could be identified in MRI scans and in plastinations. DISCUSSION: Primarily, the SFB provides a gliding space for the mobile part of the popliteus muscle over the tibia. The SFB lies within the tibial concavity, ventral to the popliteus muscle. This is exactly where embryologically, the popliteal artery passes through, before its involution in later stages. Therefore, the SFB may show the former perivascular autonomic nerves which encompass the embryologically created arteries, from which we have seen the arterial remnants. The nerves seen here form neurovascular bundles which could be a source of pain, when compressed. This anatomy may explain the autonomic component of pain in the deep lateral region of the knee. The SFB is functional fat, comparable to the Hoffa's fat pad in the ventral knee.

Spatial proteomics in three-dimensional intact specimens.

Spatial molecular profiling of complex tissues is essential to investigate cellular function in physiological and pathological states. However, methods for molecular analysis of large biological specimens imaged in 3D are lacking. Here, we present DISCO-MS, a technology that combines whole-organ/whole-organism clearing and imaging, deep-learning-based image analysis, robotic tissue extraction, and ultra-high-sensitivity mass spectrometry. DISCO-MS yielded proteome data indistinguishable from uncleared samples in both rodent and human tissues. We used DISCO-MS to investigate microglia activation along axonal tracts after brain injury and characterized early- and late-stage individual amyloid-beta plaques in a mouse model of Alzheimer's disease. DISCO-bot robotic sample extraction enabled us to study the regional heterogeneity of immune cells in intact mouse bodies and aortic plaques in a complete human heart. DISCO-MS enables unbiased proteome analysis of preclinical and clinical tissues after unbiased imaging of entire specimens in 3D, identifying diagnostic and therapeutic opportunities for complex diseases. VIDEO ABSTRACT.

Sacroiliac innervation.

PURPOSE: To investigate the innervation pattern of the sacroiliac region, especially with regard to the sacroiliac joint (SIJ). Dorsal SIJ innervation was analyzed and described. Our main hypothesis was that nerves reach the SIJ dorsally, passing ligamental compartments, as this would explain dorsal SIJ pain. METHODS: To examine sacroiliac innervation, we followed the nerves in over 50 specimens over several years. Plastinated slices were evaluated, nerves in the region were stained histologically, and the data were summarized as 3D models. RESULTS: The Rami communicans and posterior branches of the spinal nerves and their branches that form a dorsal sacral plexus and communicating branches, together with corresponding vessels, were observed to form neurovascular bundles embedded by tiny fatty connectives in gaps and tunnels. Branches of L5-S1 pass the inner sacroiliac ligaments (the interosseous sacroiliac ligament and axial interosseous ligament). The outer sacroiliac ligaments (posterior sacroiliac ligaments, long posterior sacroiliac ligament, sacrotuberal ligament, thoracolumbar fascia) are passed by the S1-S4 branches. However, although the paths of these nerves are in the direction of the SIJ, they do not reach it. It is possible that impingement of the neurovascular bundles may result in pain. Moreover, the gaps and tunnels connect to the open dorsal SIJ. CONCLUSION: Our findings suggest that Bogduk's term "sacroiliac pain" correlates to "sacroiliac innervation", which consists of "inner-" and "outer sacroiliac ligament innervation", and to ventral "SIJ pain". The watery gaps and tunnels observed could play a significant role in innervation and thus in the origins of SIJ pain. LEVEL OF EVIDENCE: Individual cross-sectional studies with consistently applied reference standard and blinding.

The sacrotuberous ligament is preloaded in situ.

The objective of this study was to evaluate the intrinsic preload of the sacrotuberous ligament. Preload measurements and anatomical experiments were performed on 20 specimens from 10 human cadavers and assessed to consider the thesis of the ligamentous tension band system as a possible load distribution. The result was an unexpectedly high preload force with an overall average of 118 N ± 74 N. Age has been significantly different between females and males in the cohort (median 94 vs. 77 years). Nevertheless, there is preliminary evidence of the sex-dependent sacrotuberous ligament preload force with an average value of approximately 65 N for the 10 female cadaver specimens and 172 N for the 10 male cadaver specimens. The assessment of further influencing factors and their statistical evaluation also showed a dependence of the sacrotuberous ligament preload force on body height, age and elastin content. Thus, the sacrotuberous ligament is more preloaded in the cadaver than previously assumed in the literature. Therefore, and contrary to most assumptions, it could possibly also be more preloaded in a living person in an upright position under a muscular load. This leads to the hypothesis that pelvic stability is more dependent on ligamentous preload than previously thought. These considerations should be taken more into account in numerical simulations of sacroiliac joint function.

Scalable tissue labeling and clearing of intact human organs.

Advances in tissue labeling and clearing methods include improvement of tissue transparency, better preservation of fluorescence signal, compatibility with immunostaining and large sample volumes. However, as existing methods share the common limitation that they can only be applied to human tissue slices, rendering intact human organs transparent remains a challenge. Here, we describe experimental details of the small-micelle-mediated human organ efficient clearing and labeling (SHANEL) pipeline, which can be applied for cellular mapping of intact human organs. We have successfully cleared multiple human organs, including kidney, pancreas, heart, lung, spleen and brain, as well as hard tissue like skull. We also describe an advanced volumetric imaging system using a commercial light-sheet fluorescence microscope that can accommodate most human organs and a pipeline for whole-organ imaging and visualization. The complete experimental process of labeling and clearing whole human organs takes months and the analysis process takes several weeks, depending on the organ types and sizes.

Degeneration of the lumbar spine and its relation to the expression of collagen and elastin in facet joint capsules and ligament flavum.

OBJECTIVE: The aim of the study was to assess the relationship between the expression of elastin, collagen type I, II,III and the degenera- tion of the facet joint capsule and the ligamentum flavum. METHODS: 10 patients (4 male, 6 female) (mean age 61 ± 14,9) undergoing surgery for degenerative lumbar spine syndrome and 5 cadav- ers (3 male, 2 female) (age of death 87 ± 8,6 years) were included in this study. One set of tissue samples was taken from each patient in the patient group intraoperatively and two sets of samples were taken from each cadaver in the cadaver group posthumosly from the ligamentum flavum (medial and lateral) and from the facet joint capsules (superior and inferior articular process) at the L4/5 segment. Western blot analysis was performed for collagen types I, II, III and for elastin. Disc degeneration was scored according to the Pfirmann Classification, facet joint arthrosis was scored according to the Fujiwara Classification and their relationship with protein expression was investigated. RESULTS: There was a strong expression of Collagen type I in the patient group (PG) compared to the body donor group (BDG) in the facet joint capsule (FJC) and in the lateral samples of the ligamentum flavum. Samples of the FJC showed lower expression of elastin in the PG compared with the BDG, but without statistical significance. An increased expression of collagen type I compared to elastin in the PG could be shown. In contrast, elastin predominated in the samples of the BDG group compared to collagen type I (collagen type I/ elastin PG: PAsup 2,78; PAinf 2,61; LFmed 2,23; 225 LFlat 1,83; BDG: PAsup 0,15; PAinf 0,2; LFmed 0,2; LFlat 0,27). Rank correlation coefficient according to Spearman showed low to moderate correlations for collagen type I, III and elastin for the degree of disc degeneration accord- ing to Pfirrmann and the degree of facet joint osteoarthritis according to Fujiwara, all of them without statistical significance. CONCLUSION: This study has shown us that in the context of degenerative changes of the lumbar spine, there is an increased expression of collagen type I and a dominance over elastin. LEVEL OF EVIDENCE: Level III, Diagnostic Study.

Levator scapulae and rhomboid minor are united.

Pain over the superior angle of the scapula is a common musculoskeletal symptom. It is often accompanied by radiating pain to the neck, head, and shoulder. The aetiologies can be varied but may also be idiopathic in nature. To explore the fascial connections of this region, we studied 26 unembalmed, -two Thiel and one alcohol body-donors of science, by dissection, histological probes, and plastinations. When removing the descending and transverse fibres of the trapezius, a large prominent triangular area of white connectives is revealed, varying in mass. A subdivision of these connectives can be further dissected to prove that the rhomboid minor and levator scapulae muscles are interconnected and enclosed by connectives. Between these two muscles a bridge of connective tissue, containing fat, is observed. These connectives end cranially at the surface of the splenius capitis, and at the midline, containing vessels and nerves, as supported by histology and plastinations. This unification is separate from the rhomboid major muscle but overlaps with the latter dorsally. It connects to the superior angle of scapula and its upper medial borders, respectively, and cranially to the root of the spine of the scapula. Beneath the united levator scapulae and rhomboid minor, described here, the serratus posterior superior and possibly serratus anterior form a hypomochlion or fulcrum at the superior angle of the scapula. Any tension on this unified entity can unbalance this fulcrum. Investigating the connections between these two unified muscles may help explain the often idiopathic nature of superior scapular pain, and the success or failure of surgery, and other treatments.

In vivo detection of the lumbar intraforaminal ligaments by MRI.

PURPOSE: Intraforaminal ligaments (IFL) are of great interest to anatomists and clinicians to fully understand the detailed anatomy of the neuroforamina and to diagnose unclear radicular symptoms. Studies published until now have described radiological imaging of the IFLs using magnetic resonance imaging (MRI) on donor bodies. In the present study, we investigated the detectability of lumbar IFLs in vivo in adults using the high spatial resolution of the constructive interference in steady state (CISS) sequence. METHODS: A total of 14 patients were studied using a 1.5 T MRI scanner. The lumbar spine was imaged using the parasagittal CISS sequence, and the detectability of the IFLs was assessed for each lumbar level. All image datasets were analyzed by a radiologist, an orthopedic surgeon, and an anatomist. Interrater reliability was expressed as Fleiss' Kappa. Using a single data set, a three-dimensional (3D) model was created to map the location of the IFLs within the intervertebral foramen (IF) and the immediate surrounding vessels. RESULTS: Overall, the radiologist was able to detect IFLs in 60% of all imaged IFs, the orthopedic surgeon in 62%, and the anatomist in 66%. Fleiss' Kappa for the various segments varies from 0.71 for L4/5 up to 0.90 for L3/4. CONCLUSION: Lumbar IFLs were successfully detected in vivo in every patient. The detection frequency varied from 42-86% per IF. We demonstrated reproducible imaging of the IFLs on MRI, with good interrater reliability. The present study was a launching point for further clinical studies investigating the potential impact of altered IFLs on radicular pain.

The Sacroiliac Joint as a Cause of Pain - Review of the Sacroiliac Joint Morphology and Models for Pain Genesis. / Das Iliosakralgelenk als Generator für Rückenschmerz. Ein Review über Morphologie und Erklärungsmodelle zur Schmerzgenese.

INTRODUCTION: In recent years, the sacroiliac joint has become increasingly important as a generator of low back pain with and without pseudo-radicular pain in the legs. Up to 27% of reported back pain is generated by disorders in the sacroiliac joint. METHOD: This review is based on a selective literature search of the sacroiliac joint (SIJ) as a possible pain generator. It also considers the anatomical structures and innervation of the sacroiliac joint. RESULTS: The SIJ is a complex joint in the region of the posterior pelvis and is formed by the sacrum and the ilium bones. The SIJ is very limited in movement in all three planes. Joint stability is ensured by the shape and especially by strong interosseous and extraosseous ligaments. Different anatomical variants of the sacroiliac joint, such as additional extra-articular secondary joints or ossification centres, can be regularly observed in CT scans. There is still controversy in the literature regarding innervation. However, there is agreement on dorsal innervation of the sacroiliac joint from lateral branches of the dorsal rami of the spinal nerves S I-S III with proportions of L III and L IV as well S IV. Nerve fibres and mechanoreceptors can also be detected in the surrounding ligaments. CONCLUSION: A closer look at the anatomy and innervation of the SIJ shows that the SIJ is more than a simple joint. The complex interaction of the SIJ with its surrounding structures opens the possibility that pain arises from this area. The SIJ and its surrounding structures should be included in the diagnosis and treatment of back and leg pain. Published literature include a number of plausible models for the sacroiliac joint as pain generator. The knowledge of the special anatomy, the complex innervation as well as the special and sometimes very individual functionality of this joint, enhance our understanding of associated pathologies and complaints.

The topography and morphometrics of the pubic ligaments.

BACKGROUND: Conflicting anatomical reports and the little attention given to the pubic ligaments impede the interpretation of radiological and clinical examinations on groin pain. Morphometric data on the pubic ligaments are lacking. METHODS: The muscular relations of the symphysis pubis were examined in layered dissection (n = 10), hemipelves (n = 60) and (un)stained plastinated body slices of body donors (n = 3). The sagittal and coronal areas, width, mean and maximum thickness of pubic ligaments were determined. RESULTS: The adductor longus, brevis, rectus abdominis and pyramidalis muscles are attached to the anterior pubic ligament (APL). The adductor brevis and gracilis muscle are connected to the inferior pubic ligament (IPL). The IPL and superior pubic ligament (SPL) are thicker than the APL and posterior pubic ligament (PPL). The PPL is the thinnest pubic ligament. The APL has a larger sagittal area in women than in men compared to the IPL. The SPL and IPL are thicker in men compared to women. CONCLUSION: The APL is the ligamentous anchor for the originating and inserting muscles. Investigations of the pubic ligaments might help to determine symphysis instability or severity of injury and should be included as a further criterion for surgical management.

Topography and evidence of a separate "fascia plate" for the femoral nerve inside the iliopsoas - A dorsal approach.

The femoral nerve stretch test is an essential part of clinical neurological examinations. This test is performed alongside Magnetic Resonance Imaging (MRI) to determine if there is any evidence of nerve root irritation, usually as a consequence of disc prolapse. The test occasionally gives false positive results. Why such false positives can occur, is subject to continued research, however, no obvious reason has yet emerged. We hypothesize that connectives of the femoral nerve may explain such a phenomenon. To see these connectives, we approached the femoral nerve from dorsal in 12 cases. With the use of ink injection into the subparaneural compartment of the femoral nerve and dissections, a thin transparent structure can clearly be seen that is separate from the epineurium, perineurium, and a paraneural sheath. A continuation of the paraneural sheath produces a fascia plate approximately 1.5 cm in width and with a thickness of around 3 mm, which not only circumnavigates the nerve but projects into the surrounding tissues. Our qualitative observations show that not only does this femoral nerve fascia plate exists, but it also contains nerves and vessels. Furthermore, we show that the femoral nerve is connected to the myofascial complex of the iliopsoas, and in a separate fascia plate from the iliopsoas fascia. This plate is a hitherto neglected connective which extends as far as the spinal dura mater. Evidence from our plastinates and histological sections suggests that when tension is applied to the femoral nerve during the femoral nerve stretch test, tension is also applied to the femoral nerve fascia plate. The femoral nerve fascia plate could be a specific factor that contributes to pain resulting in a false positive femoral nerve stretch test.

The arterial blood supply of the symphysis pubis - Spatial orientated and highly variable.

BACKGROUND: Open surgical treatment of the pubic region and adductor related pathologies require an exact knowledge of the arterial blood supply of the symphysis pubis that seems furthermore important to explain the hematogenous occurrence of symphysitis. Pubic bone marrow oedema (PBME) is a frequent occurring magnetic resonance imaging finding in groin pain. However, even asymptomatic athletes present PBME and a correlation to the physical activity or higher blood flow was suggested. Data on the vascular anatomy of the symphysis pubis are rare. METHODS: Ten formaldehyde-embalmed cadavers were dissected, and the arterial blood supply was investigated and photographically documented. RESULTS: In the majority of cases the following pattern was determined: superior-inferior epigastric artery (n=12 hemipelves), inferior - dorsal artery of the penis/dorsal artery of the clitoris (n=16), posterior- obturator artery (n=16 hemipelves), anterior- deep external pudendal artery (n=14 hemipelves). Besides variations for the deep external pudendal artery anteriorly, we observed a highly variable arterial supply, especially superior. Superior in 4/10 cadavers, inferior in 0/10 cadavers, posterior in 2/10 cadavers and anterior in 5/10 cadavers side variations were found. CONCLUSION: The symphysis pubis has a spatial and rich organized arterial blood supply with several variations. Despite the symphysis pubis is recognized as bradytroph, the high number of vessels is presumably required in stress situations for example in heavy training.

Integrity of the pectineal ligament in MRI correlates with radiographic superior pubic ramus fracture displacement.

BACKGROUND: Estimating the stability of pelvic lateral compression fractures solely by static radiographs can be difficult. In this context, the role of anterior pelvic soft tissues as potential secondary stabilizer of the pelvic ring has hardly been investigated. PURPOSE: To correlate the initial radiographic appearance of the pubic ramus fracture with the integrity of the pectineal ligament, a strong ligament along the pecten pubis. MATERIAL AND METHODS: In total, 31 patients with a pelvic lateral compression fracture (AO/OTA 61- B1.1/B2.1) with 33 superior pubic ramus fractures and available post-traumatic radiographs (pelvis anteroposterior, inlet, outlet) and magnetic resonance imaging (MRI) of the pelvis with fat-suppressed coronal images were reviewed retrospectively. Radiographic superior pubic ramus fracture displacement was measured and correlated to the degree of MR-morphologic alterations of the pectineal ligament (grade 0 = intact, grade 3 = rupture). RESULTS: In the majority of fractures (72.7%), associated MR-morphologic alterations of the pectineal ligament were present. Radiographic displacement and MRI grading showed a strong positive correlation (Spearman rho = 0.783, P < 0.001). The sensitivity and specificity for a radiographic displacement of >3 mm on plain radiographs to detect a structural ligament lesion on MRI (grade 2 and higher) were 73% and 100%, respectively. CONCLUSION: Radiographic displacement of superior pubic ramus fractures >3 mm is a strong indicator for a structural lesion of the pectineal ligament. Future studies should investigate the potential biomechanical importance of this ligament for pelvic ring stability.