Sacroiliac Ligaments Research Articles

Pubic symphysis diastasis an unusual postpartum complication

A 22-year-old G2 P1 presented to A & E with severe bilateral groin pain with associated frequency and dysuria on day 3 post partum. The groin pain was excruciating and...

The Occurrence of Strain Symptoms in the Lumbosacral Region and Pelvis During Pregnancy and After Childbirth

Objective The etiology and pathology of pain in the lumbosacral region and pelvis of pregnant women during and after pregnancy have not been fully determined. This study evaluated if lower back pain during pregnancy and after childbirth is connected with static alterations in the alignment of the pelvis, dysfunction of sacroiliac joints, and irritation of the pelvic ligaments and spine in the lumbosacral region. Methods This study was carried out on a group of 30 women in their eighth month of pregnancy and through 3 months after childbirth. Techniques of manual examination were used to determine the strain. Static alteration of the pelvis was evaluated in both the sitting and standing positions on the basis of alignment of the posterior superior iliac spines. Irritation of the iliolumbar ligaments, sacrotuberous, sacroiliac, and interspinous ligaments was evaluated by means of pressure palpation. Disorders of sacroiliac joint function were evaluated with the Patrick FABERE test, the standing Gillet test, and the standing and sitting flexion tests. Results The most frequently irritated ligaments in the lumbar region are interspinous (60%), iliolumbar (40%), and sacroiliac (36%). Conclusions In women, in their eighth month of pregnancy and after childbirth, disorders of static alterations in pelvis alignment and sacroiliac joint dysfunction may occur. The state of pregnancy may result in strain symptoms in the lumbosacral region and pelvis with variable pain intensifying in various static positions.

Clinical Effectiveness of Botulinum Toxin A Compared to a Mixture of Steroid and Local Anesthetics as a Treatment for Sacroiliac Joint Pain

The sacroiliac joint (SIJ) is one of the sources of low back pain and referred pain to the lower limb. Steroid injections have been used to treat SIJ pain, but this frequently necessitates repeated injections. Botulinum toxin (BT) type A has been shown to provide significant reduction of joint pain, and functional improvements. This study investigated the efficacy of BT for reducing SIJ pain and maintaining a clinical effect, compared with steroid injections. Prospective case control study. Spine hospital. Patients who were diagnosed with SIJ syndrome based on physical examination and diagnostic SIJ injection were selected. Either Dysport (BT group) or a mixture of triamcinolone and lidocaine (triamcinolone and local anesthetics [TA] group) was injected into the posterior sacroiliac ligaments under C-arm fluoroscopy. Numeric Rating Scale (NRS) and Oswestry Disability Index (ODI) were used for evaluation at pretreatment, 1 month, 2 months, and 3 months after treatment. At 1 month, the BT and TA group showed no significant differences in NRS or ODI. However, at 2 and 3 months, the BT group had significantly lower scores in NRS and ODI than did the TA group. BT shows clinical usefulness in pain reduction and for functional improvement in patients with SIJ pain. This effect was maintained for 3 months following the injection, by which time the effects of TA had diminished.

Sacroiliac joint injection using the posterior superior iliac spines as landmarks: a preliminary study using cadavers

It is estimated that about 30% of cases of low back pain (LBP) are due to sacroiliac joint dysfunctions (SIJD). Accurate clinical diagnosis and treatment of LBP caused by SIJD is difficult without image guided techniques for needle placement into the sacroiliac joint cavity. Limitations in the availability of such image guided techniques in health institutions in developing countries are an obvious and major restriction, however the use of fundamental anatomic landmarks for surface marking of the sacroiliac joint for needle placement into the joint cavity is suggested as a useful substitute. Twelve adult cadavers (used for teaching) obtained from the Department of Anatomy, School of Medical Sciences, University of Science and Technology between 2006 and 2008 were studied. For each cadaver, the gluteal region was dissected to expose the bony posterior superior iliac spines (PSIS) and the posterior long sacroiliac ligaments. The proximal third of both posterior long sacroiliac ligaments were removed to expose the clefts between the two bones on both sides for the introduction of an IV cannula introducer needle 24G (Suruflon, Suru International PVT, Ltd, Mumbai) into the cleft between the two bones inferior to PSIS and advanced in a direction where the penetration was without resistance. A second needle was placed perpendicularly at the PSIS and radiographs of the posterioanterior view of the cadaveric pelvis were taken to confirm the placement of the needle in the sacroiliac joint, using Turdde 38 mobile X-ray machine. The needle position from the posterior superior iliac spine and its angle of inclination from the para-sagittal plane were measured. The data was analyzed using graph pad prism. The position of the needle ranged from 2 to 3.7 cm inferior to PSIS in all the cadavers with a mean of 2.52 cm (SE 0.09) for right and 2.59 cm (SE 0.20) for left. There was no significant difference between the right and the left needle positions of the joint (paired t-test, p>0.05). The angle of inclination of the needle ranged from 10o to 30o medial to the parasagittal plane with a mean of 24.58o (SE 2.2) and 25.12o (SE 1.8) for right and left respectively. These results show that an IV cannula introducer needle placed at 2-3 cm inferior to PSIS and directed at angle of 20-30o medial to the para-sagittal plane would get into the synovial part of the sacroiliac joint and confirms the intra-articular needle position within the sacroiliac joint using the PSIS as the anatomic landmark. These quantitative data present baseline values forfurther clinical investigation.

Novel Insights Into the Sacroiliac Joint Ligaments

The ligaments of the human sacroiliac joint (SIJ) were investigated morphometrically. A macroscopical study was performed to measure the anterior sacroiliac ligament (ASL), the interosseous sacroiliac ligament (ISL), and the posterior sacroiliac ligament (PSL), applying different methods of ligament visualization. Little is known about the SIJ ligaments, especially about the ISL. Pelvic computer simulations neglect these ligaments due to the lack of information. Computer simulations of the SIJ ligaments may help to improve the clinical outcome of SIJ operations. Seven-Tesla MR images, CT images, and corresponding thin slice plastinates of the SIJ of 1 male and 1 female specimen were obtained. Serial sections of the SIJ of 32 frozen specimens (13 males, 19 females) were generated to gather measurements of the SIJ ligaments. By means of the MR images and the plastinates, a virtual reconstruction of the SIJ ligaments was accomplished. Parallelepipeds were attributed to the cranial, middle, and caudal parts of all SIJ ligaments. This allowed precise measurements and statistical comparison including positional relationships. The ISL volumes and origin surfaces were the largest. Statistically, the ASL and PSL parameters were larger in males, while the ISL parameters were larger in females. The height of the cranial ASL part showed large negative correlations in spite of positive correlations of the other heights. The combined use of high-resolution MRI and thin slice plastination allows precise reconstructions of the SIJ ligaments. With these techniques, the ligaments can be visualized in situ and described morphometrically if based on substantive data. The SIJ ligaments are gender-dependent. This has to be taken into account for pelvic computer simulations.

Branch Blockade of the Dorsal Sacral Rami

The recent original research article by Dreyfuss and colleagues [1], presents an interesting perspective on a potential technique to diagnose sacroiliac joint pain of extra-articular origin. However, some questions arise out of the described methodology, which we believe may merit further discussion. Recent morphological and histological study of the posterior sacroiliac region [2] indicate a specialized and metameric arrangement of a deep fascial layer that is related to a number of adjacent structures in the region. These include the individual dorsal sacral foramen, the associated lateral and medial branches of the dorsal sacral rami, and the long posterior sacroiliac ligament. The delicate neurovascular lateral branches of the dorsal sacral rami form a variable network of interconnected lateral branches from L5 to S4 dorsal rami [2–4], which lie immediately posterior to the dorsal sacral surface. Significantly, the lateral branches lie within a protective and continuous layer of loose connective and adipose tissue, as they wend their variable path between the …

The Ability of Multi-Site, Multi-Depth Sacral Lateral Branch Blocks to Anesthetize the Sacroiliac Joint Complex

To determine the physiologic effectiveness of multi-site, multi-depth sacral lateral branch injections. Double-blind, randomized, placebo-controlled study. Outpatient pain management center. Twenty asymptomatic volunteers. The dorsal innervation to the sacroiliac joint (SIJ) is from the L5 dorsal ramus and the S1-3 lateral branches. Multi-site, multi-depth lateral branch blocks were developed to compensate for the complex regional anatomy that limited the effectiveness of single-site, single-depth lateral branch injections. Bilateral multi-site, multi-depth lateral branch green dye injections and subsequent dissection on two cadavers revealed a 91% accuracy with this technique. Session 1: 20 asymptomatic subjects had a 25-g spinal needle probe their interosseous (IO) and dorsal sacroiliac (DSI) ligaments. The inferior dorsal SIJ was entered and capsular distension with contrast medium was performed. Discomfort had to occur with each provocation maneuver and a contained arthrogram was necessary to continue in the study. Session 2: 1 week later; computer randomized, double-blind multi-site, multi-depth lateral branch blocks injections were performed. Ten subjects received active (bupivicaine 0.75%) and 10 subjects received sham (normal saline) multi-site, multi-depth lateral branch injections. Thirty minutes later, provocation testing was repeated with identical methodology used in session 1. Presence or absence of pain for ligamentous probing and SIJ capsular distension. Seventy percent of the active group had an insensate IO and DSI ligaments, and inferior dorsal SIJ vs 0-10% of the sham group. Twenty percent of the active vs 10% of the sham group did not feel repeat capsular distension. Six of seven subjects (86%) retained the ability to feel repeat capsular distension despite an insensate dorsal SIJ complex. Multi-site, multi-depth lateral branch blocks are physiologically effective at a rate of 70%. Multi-site, multi-depth lateral branch blocks do not effectively block the intra-articular portion of the SIJ. There is physiological evidence that the intra-articular portion of the SIJ is innervated from both ventral and dorsal sources. Comparative multi-site, multi-depth lateral branch blocks should be considered a potentially valuable tool to diagnose extra-articular SIJ pain and determine if lateral branch radiofrequency neurotomy may assist one with SIJ pain.

Prognostic factors for recovery from postpartum pelvic girdle pain

Pelvic girdle pain (PGP) has a high incidence during pregnancy and in some women pain will persist for years. Most studies have used pain as the outcome measure, and little attention is given to functioning or disability. A better understanding of prognostic factors for recovery seems important for clinical care and treatment. The aim of the present paper was to identify prognostic factors for recovery from postpartum PGP and disability, and to determine the impacts of prognostic factors when pain intensity and disability are used as outcome measures. Seventy-eight women with diagnosed PGP were included 6-16 weeks postpartum. Possible prognostic factors were obtained through clinical tests and questionnaires at baseline. The clinical tests were posterior pelvic pain provocation (P4) test, active straight leg raise (ASLR) test and pain provocation of long dorsal sacroiliac ligament (LDL). One year postpartum outcome measures were obtained by Oswestry disability index (ODI ver 2.0) and worst evening pain (VAS 0-100). Multiple linear regression and logistic regression analyses were used to identify significant prognostic factors. At baseline 60% believed they would recover and 40% were uncertain or believed they would not recover. Fifty per cent had a history of low back pain (LBP), and 20% had high emotional distress (HSCL25-item > or =1.75). About 75% had positive LDL and P4 at both sides and 24% had pain located to all three pelvic joints. Forty per cent had ASLR scores of at least 4 (sum score range 0-10). Multivariate analyses showed consistently that ASLR and belief in improvement were statistical significant predictors for both disability and pain as outcome measures. ASLR score <4 predicted 10 points lower ODI and 19 points lower evening pain compared with having ASLR score of at least 4. Pain location was a statistical significant predictor in only one analysis. History of LBP or high psychological distress was not prognostic for recovery. ASLR test and belief in improvement are predictors of clinical significance in women having PGP postpartum.

The Ability of Single Site, Single Depth Sacral Lateral Branch Blocks to Anesthetize the Sacroiliac Joint Complex

To determine the physiologic effectiveness of single site, single depth sacral lateral branch injections. Randomized, controlled, and double-blinded study. Outpatient pain management center. Fifteen asymptomatic volunteers. The dorsal sacroiliac ligament was probed and the sacroiliac joint was injected with contrast medium until capsular distension occurred. The presence or absence of pain with each maneuver was noted. Under double-blind conditions, subjects returned 1 week later for L5 dorsal ramus and S1-4 lateral branch injections; 10 subjects received 4% lidocaine (active) injections while five subjects received saline (control) injections. After 30 minutes, subjects had repeat ligamentous probing and capsular distension of the same sacroiliac joint that was previously tested. The presence or absence of pain with each maneuver was noted. In a parallel anatomic study, S1 and S2 lateral branch injections with green dye were performed on two nonembalmed cadavers. Dissection was undertaken to quantify the degree of staining of these target lateral branch nerves. Presence or absence of pain for ligamentous probing and sacroiliac joint capsular distension. Forty percent had no discomfort upon repeat ligamentous probing after active lateral branch injections while 100% retained pain upon repeat ligamentous probing with control lateral branch injections. Forty percent of the active group and 20% of the control group did not feel repeat capsular distension of the sacroiliac joint after the lateral branch injections. In the anatomic study, 11 lateral branch nerves were isolated while staining occurred in only four cases or 36%. Anatomic limitations exist with single site, single depth sacral lateral branch injections rendering them physiologically ineffective on a consistent basis.

The long posterior sacroiliac ligament: A histological study of morphological relations in the posterior sacroiliac region

Objectives To investigate the morphology of the long posterior sacroiliac ligament (LPSL) and its potential relationship to adjacent structures in the posterior sacroiliac region, and to consider any possible functional anatomical implications that may arise. Methods Four large cadaveric tissue blocks of the posterior sacroiliac region were utilised in this qualitative histological study. The blocks underwent demineralisation in ethyl-diamine-tetra-acetic acid (EDTA). The end-point was determined radiographically. The demineralised tissue blocks were subsequently processed and a base sledge microtome used to section the blocks. Sequential sections were stained with Harris haematoxylin and alcoholic eosin (H&E) and mounted on glass slides prior to viewing under a light microscope. Results The LPSL was observed to have proximal and distal regions of osseous attachment. Between these regions of attachment the middle LPSL was observed as a confluence of three layers: the erectores spinae aponeurosis, the ‘deep fascial layer’ and the gluteal aponeurosis. Deep to the ‘deep fascial layer’ a layer of adipose and loose connective tissue was observed. Lateral branches of the dorsal sacral rami were identified within this layer. Conclusions The middle long posterior ligament appears to provide a pathway for the lateral branches of the dorsal sacral rami between the posterior sacral region and the gluteal region. This histological study provides a morphological basis for the proposal that putative sacroiliac joint pain may be due to an entrapment neuropathy of the lateral branches of the dorsal sacral rami at the long posterior sacroiliac ligament.

Marie-François Xavier Bichat (1771–1802) and his contributions to the foundations of pathological anatomy and modern medicine

Marie-François Xavier Bichat (1771-1802) was a prominent French anatomist during a time of revolution and one of the founders of French scientific medicine. He conducted several experimental studies, which laid the foundation for modern physiology. Based on autopsy findings, Bichat introduced 21 tissues as the basic elements of organs. His name is carried on by several eponyms in anatomy and histology; Bichat's fossa (pterygopalatine fossa), Bichat's protuberance (buccal fat pad), Bichat's foramen (cistern of the vena magna of Galen), Bichat's ligament (lower fasciculus of the posterior sacroiliac ligament), Bichat's fissure (transverse fissure of the brain) and Bichat's tunic (tunica intima vasorum). This paper deals with the life and works of this early pioneer in anatomy and physiology.

Physical Characteristics of Women With Severe Pelvic Girdle Pain After Pregnancy

Descriptive cohort study. This study aims to further elucidate the differences in physical characteristics of women with severe pregnancy-related pelvic girdle pain (PGP). There is increasing interest in pelvic girdle pain (PGP). To our knowledge, this is the first study on a large population of patients with severe PGP, after pregnancy, based on high cutoff scores on diagnostic PGP tests. Two hundred five patients were selected from the outpatient clinic of a rehabilitation center. Patients were divided in 3 inclusion groups based on the total number of positive scores on 5 diagnostic tests; i.e., active straight leg raise test, posterior pelvic pain provocation test, long dorsal sacroiliac ligament test, and hip abduction and adduction strength tests. These inclusion groups were related to the data on trunk strength test, general provocation tests, Quebec Back Pain Disability Scale (QBPDS) and activities of daily living. A typical pattern of PGP emerges from this study. The mean group score on the active straight leg raise, posterior pelvic pain provocation, and long dorsal sacroiliac ligament tests became higher when more than 3 inclusion tests were positive. Hip abduction and adduction strength became lower with more positive tests. The QBPDS score was overall high and significantly higher for 5 positive tests compared with 3 and 4 positive tests. This shows that the number of positive tests, the individual score on the diagnostic tests, and the QBPDS could all be an indicator for severity of PGP. Among the general pain provocation tests, both the passive hip flexion test and the upper and middle sacral thrust test scored high. The maximal isometric strength of trunk muscles was below the 10th percentile compared with women without complaints and was even less for 5 positive inclusion tests. It is confirmed that there is a typical order for difficulties with daily activities for PGP patients as follows (most difficult first): standing still, cycling, walking, sitting, and lying. The study shows that the level of severity in PGP can be adequately assessed by a combination of specific tests.

Nociceptive Nerve Fibers in the Sacroiliac Joint in Humans

A positive response to sacroiliac joint intra-articular infiltration with local anesthetics is used to confirm sacroiliac joint pain. However, current anatomical and histological knowledge concerning the anatomy of pain perception within the sacroiliac joint intra- and peri-articular structures is insufficient to explain the efficacy of this infiltration, because of the use of unspecific histochemical visualization techniques. In this study, immunohistochemistry for calcitonin gene-related peptide (CGRP) and substance P was used to trace nociceptive fibers and receptors in the anterior and interosseous sacroiliac ligaments obtained from 5 human cadavers without history of sacroiliac joint pain. Microscopic analysis of stained slides showed presence of CGRP and substance P immunoreactive fibers. Thick, wavy, formed bundles were observed in dense and loose connective tissue, whereas single, beaded nerve fibers, occasionally ramified, were observed more frequently in the dense connective tissue and next to blood vessels. Based on their morphologic features, these immunoreactive structures were classified as receptors type IV. Additionally, receptors type II were found in anterior and interosseous ligaments, which contained CGRP or substance P immunoreactive free nerve endings. We conclude that the presence of CGRP and substance P immunoreactive fibers in the normal anterior capsular ligament and interosseous ligament provides a morphological and physiological base for pain signals originating from these ligaments. Therefore, diagnostic infiltration techniques for sacroiliac joint pain should consider extra- as well as intra-articular approaches.

Effective Pain Palliation in Fibromyalgia Syndrome Patients with Botulinum Toxin Type-A: Case Series of 25

Background: These case reports document effective treatment using botulinum toxin type-A [BTX-A] in fibromyalgia syndrome [FMS] patients. Outcome measures [including pain scales, Fibromyalgia Impact Questionnaire, algometry] were recorded on 25 FMS patients undergoing repeated BTX-A injections [one to five years duration].Findings: Pain and function were improved in these patients. Muscles injected with good response included the frontalis, corrugators [for headache], levator scapulae, pectoralis minor [neck/ shoulder pain], paraspinals, piriformis and sacroiliac ligaments [low back pain]. The BTX-A worked best with biomechanical approaches incorporating postural correction and core stability strengthening.Conclusion: Our clinical experience suggests that pain in FMS patients may be effectively managed with BTX-A.

Movement between the equine ilium and sacrum: in vivo and in vitro studies

Sacroiliac disease (SID) is an important cause of loss of performance in horses, yet little is known about the biomechanics of movement of the sacroiliac joint (SIJ). (a) To document the presence of equine SIJ motion by measuring the change in cross-sectional area (CSA) of the dorsal portion of the dorsal sacroiliac ligament (DSIL) during application of manual forces to the pelvis, and to ascertain if this varied between horses with SID and normal horses; (b) To determine the amount and direction of motion available at the equine SIJ using 3-D orientation sensors, and how motion is limited by the DSIL and sacrotuberous ligament. Study 1: CSA obtained ultrasonographically was compared before and during manual force application to the ilium, on a group of 10 horses, 5 with SID and 5 clinically normal. Study 2: direction and degrees of motion between sacrum and ilium were measured in 8 cadaveric SIJs. 3D orientation sensors were mounted to the fixated sacrum and the moveable ilium, and relative motion recorded between the 2 bones when manual forces were applied to the ilium. Study 1 showed a significant decrease in the CSA of the equine DSIL during application of manual forces to both tuber coxae (TC) (P<0.001) and tuber sacrale (TS) (P<0.001) when compared to at rest. Study 2 described range of motion to be greatest in the transverse or coronal plane, when lateral and oblique forces were applied to the pelvis, and recorded significant increases (P<0.05) in range of motion in the sagittal plane following resection of both the DSIL and sacrotuberous ligament. The change in DSIL CSA with application of manual force may be due to a lengthening of the ligament, reflecting equine SIJ motion in vivo. The motion recorded between ilium and sacrum in vitro suggests that greatest sacroiliac motion may occur in the transverse plane. Increases in range of motion following resection of ligaments give some indication of the role of each ligament.

ULTRASONOGRAPHIC TECHNIQUE AND NORMAL ANATOMIC FEATURES OF THE SACROILIAC REGION IN HORSES

The purpose of this study was to establish the normal percutaneous ultrasonographic appearance of anatomic structures within the equine sacroiliac region. Percutaneous ultrasonography was performed in a cranial-to-caudal direction in 10 normal adult live horses. The following structures were examined in detail: supraspinous ligament, lumbar and sacral spinous processes, thoracolumbar fascia and its caudal extension, tubera sacralia, ilial wings, dorsal and lateral portions of the dorsal sacroiliac ligaments, lateral part of the sacrum, and the lateral sacral crest. After ultrasonography, all animals were euthanized and detailed dissection of the lumbosacropelvic region was performed in six horses. Four lumbosacropelvic specimens were frozen and sectioned transversely for evaluation of cross-sectional anatomy. Gross anatomic findings were correlated with ante-mortem ultrasonographic images. On percutaneous ultrasonography, all horses had tubera sacralia with a mild-to-moderate roughened surface with occasional irregular hyperechoic mineralizations located within the apophyseal cartilage of younger horses. At the level of the tuber sacrale the caudal extension of the thoracolumbar fascia joined the dorsal portion of the dorsal sacroiliac ligament and assumed two different configurations relative to the dorsal portion of the dorsal sacroiliac ligament, with the predominant configuration of the thoracolumbar fascia located medial to the dorsal portion of the dorsal sacroiliac ligament. The less frequently encountered configuration had the thoracolumbar fascia positioned dorsal to the dorsal portion of the dorsal sacroiliac ligament. Caudal to the tuber sacrale the dorsal portion of the dorsal sacroiliac ligament and thoracolumbar fascia consolidated to form a single, fused structure with a common insertion on the sacral spinous processes. A large variability in linear fiber pattern, echogenicity (small focal hypoechoic areas), ligament height, and cross-sectional measurements was identified in the fused dorsal portion of the dorsal sacroiliac ligament and thoracolumbar fascia of normal horses. Diagnosing mild-to-moderate desmitis of the fused dorsal portion of the dorsal sacroiliac ligament and thoracolumbar fascia based solely on ultrasonography may therefore be difficult. To correlate ultrasonography with histology, samples of a fused dorsal portion of the dorsal sacroiliac ligament and thoracolumbar fascia with bilateral hypoechoic lesions were submitted for histology and revealed diffuse mild-to-moderate loss of fiber density, multifocal fibrocyte degeneration, and cartilagenous metaplasia with multifocal, mild myofiber mineralization, which was compatible with age-related changes. As controls, sections of ultrasonographically normal fused dorsal portion of the dorsal sacroiliac ligament and thoracolumbar fascia from three horses demonstrated similar but milder histologic findings, which were considered normal.

Facet blockade, peridural and periradicular pain therapy

More than 80% of vertebrogenic lumbar pain is unspecific and can only be attributed to a specific anatomic structure with difficulty. The pain can emanate from the intervertebral discs, intervertebral and sacroiliac (SI) joints, musculature, and ligaments. In a maximum of 7% of cases, the pain is radicular (4% due to intervertebral discs and 3% caused by stenoses). In 7-15% of cases, the pain's origin is located in the region of the vertebral joints and in up to 15% in the region of the SI joint. Although the overwhelming majority of pain has no clear structural cause, infiltrations of medications and nerve blockades are frequently employed. The efficacy of these procedures has however not been verified in controlled studies with the exception of epidural injection of corticosteroids for radicular pain. Epidural and epiradicular application of corticosteroids appear to be effective for radicular pain, at least on a short-term basis, although controlled studies have yielded controversial results. The difficulty lies partly in the exact placement at the affected root for applying the medication. This is hardly possible with a caudal injection, while with a lumbar peridural injection and periradicular injections it is only possible under X-ray control or even better CT guidance.

Anatomy of the Interosseous Region of the Sacroiliac Joint

Anatomical study of the interosseous region of the sacroiliac joint (SIJ) complex. To document and quantify the surface topography of the interosseous region of the SIJ. A review of the literature reveals that little consideration has been given to the interosseous region of the SIJ anatomically, biomechanically, and clinically. The interosseous region of 11 cadaveric specimens (9 formalin embalmed and 2 fresh frozen) were studied. Ten specimens were 55 years of age or older and 1 was 20 years old. To view the interosseous surfaces of the sacrum and ilium the specimens were either axially sectioned (1-cm slices) or disarticulated. One fresh-frozen and 6 embalmed specimens were disarticulated and the remainder axially sectioned. The topography (surface ridging and areas of ossification) of the interosseous region was documented in all specimens and in 2 specimens the surfaces were 3-dimensionally reconstructed using modeling and animation software (MAYA; Autodesk, Inc, San Rafael, CA). Surface characteristics of the SIJ complex observed in specimens 55 years of age or older included moderate to extensive ridging of the interosseous region of the sacrum and ilium in 100% of specimens and ossification of the central interosseous region of the sacroiliac (SI) ligament in 60% of specimens. Central region ossification of the interosseous SI ligament and the presence of ridges and depressions over the opposing interosseous surfaces of the sacrum and ilium are features common to specimens that are in or beyond their sixth decade. These findings further support the contention that there is little to no movement available at this joint in older individuals.

Lateral branches of dorsal sacral nerve plexus and the long posterior sacroiliac ligament

Non-specific low back pain and peripartum pelvic pain have aetiologies that may feature the sacroiliac region. This region possesses many potential pain-generating structures sharing common sensory innervation which makes clinical differentiation of pathoanatomy difficult. This anatomical study explores the relationship between the long posterior sacroiliac ligament (LPSL) and the lateral branches of the dorsal sacral nerve plexus. Twenty-five sides of the pelvis from 16 cadavers were studied, three for histological analysis and 22 for gross anatomical dissection. We found that the LPSL is penetrated by the lateral branches of the dorsal sacral rami of predominantly S2 (96%, 21/22) and S3 (100%, 22/22), variably of S4 (59%, 13/22) and rarely of S1 (4%, 1/22). Some of the penetrating lateral branches give off nerve fibres that disappear within the ligament. These findings provide an anatomical basis for the notion that the LPSL is a potential pain generator in the posterior sacroiliac region.

Ultrasonographic examination of the equine sacroiliac region

Little information exists about the normal ultrasonographic appearance of the equine sacroiliac region, but knowledge of the ultrasonographic anatomy is necessary to understand the possible pathological changes in sacroiliac diseases. The normal ultrasonographic appearance of soft tissues and bony structures of the sacroiliac region in horses was studied in order to establish clinically relevant reference parameters. Thirteen cadaver specimens were examined using a transcutaneous approach above the tubera sacrale to image the dorsal sacroiliac ligament and the tendon of the longissimus dorsi muscle. A rectal approach was used to outline the sacroiliac joint and its adjacent structures. Thirteen sound horses with no history of back pain were examined following the same protocol as for the post mortem examinations. The tendon of the longissimus dorsi muscle can clearly be distinguished from the dorsal sacroiliac ligament, especially in longitudinal images. Transrectal examination of the sacroiliac joint consists of evaluation of the bony surfaces of the sacrum and ilium in comparison with the contralateral side. Ultrasonographic examination of the sacroiliac region provided clear images of the caudomedial border of the sacroiliac joint and its adjacent structures and is a useful aid in the diagnosis of sacroiliac joint diseases and adjacent lesions. The study has shown ultrasonography to be a useful method for examining and differentiating the longissimus dorsi muscle and the dorsal sacroiliac ligament at the level of the tubera sacrale. Diagnostic ultrasound is available to most practitioners. These reference ultrasound parameters may help to improve the diagnosis of sacroiliac diseases.