Brain Network Changes in Lumbar Disc Herniation Induced Chronic Nerve Roots Compression Syndromes.

Lumbar disc herniation (LDH) induced nerve compression syndromes have been a prevalent problem with complex neural mechanisms. Changes in distributed brain areas are involved in the occurrence and persistence of syndromes. The present study aimed to investigate the changes of brain functional network in LDH patients with chronic sciatica using graph theory analysis. A total of thirty LDH adults presenting L4 and/or L5 root (s) compression syndromes (LDH group) and thirty age-, sex-, BMI- and education-matched healthy control (HC group) were recruited for functional MRI scan. Whole-brain functional network was constructed for each participant using Pearson's correlation. Global and nodal properties were calculated and compared between two groups, including small-worldness index, clustering coefficient, characteristic path length, degree centrality (DC), betweenness centrality (BC) and nodal efficiency. Both LDH and HC groups showed small-world architecture in the functional network of brain. However, LDH group showed that nodal centralities (DC, BC and nodal efficiency) increased in opercular part of inferior frontal gyrus; and decreased in orbital part of inferior frontal gyrus, lingual cortex and inferior occipital gyrus. The DC and efficiency in the right inferior occipital gyrus were negatively related with the Oswestry Disability Index in LDH group. In conclusion, the LDH-related chronic sciatica syndromes may induce regional brain alterations involving self-referential, emotional responses and pain regulation functions. But the whole-brain small-world architecture was not significantly disturbed. It may provide new insights into LDH patients with radicular symptoms from new perspectives.

The relationship between pain and herniation radiology in giant lumbar disc herniation causing severe sciatica: 15 cases.

OBJECTIVE: To evaluate conservative treatment of giant lumbar disc herniation in patients with extreme pain and to assess temporal changes in pain levels and radiological findings with short-term follow-up. METHODS: A total of 15 patients with severe pain (as measured by visual analog scale [VAS]) due to giant lumbar disc herniation and without neurological deficits were included. All patients received conservative treatment and were followed weekly for pain and medication assessment. MRI was performed at baseline, second month and fourth month to calculate disc herniation volume. The changes in disc herniation and pain were evaluated. RESULTS: There was no relationship between pain and the regression of disc herniation in these five females and ten males with a mean age of 41.4 years. MRI results showed an average of 20.3% and 20.4% regression of disc herniation from baseline to second month, and second month to fourth month, respectively. Whereas, pain levels had reduced from an average of 90.8-13.53 by the second month, and to 3.13 by the fourth month, indicating significant success with conservative treatment. CONCLUSIONS: Regardless of the size of the herniation and the severity of the pain, patients with giant lumbar disc herniation should be encouraged to undergo conservative treatment, given that the patient does not have urinary-fecal incontinence, foot drop or progressive neurodeficit.

Imaging of peripheral nerve causes of chronic buttock pain and sciatica.

Chronic buttock pain is a common and debilitating symptom, which severely impacts daily activities, sleep, and may affect athletic performance. Lumbar spine, posterior hip, or hamstring pathology are usually considered as the primary diagnoses; however, pelvic neural pathology may be a significant cause of chronic buttock pain, particularly if there are prolonged (>6 months) buttock and/or radicular symptoms. The subgluteal space is the site of most pelvic causes of neural-mediated buttock pain, primarily relating to entrapment neuropathy of the sciatic nerve (deep gluteal syndrome), although other nerves within the subgluteal space including the gluteal nerves, pudendal nerve, and posterior cutaneous nerve of thigh may also be involved. Additionally, cluneal nerve entrapment at the iliac crest may result in "pseudo-sciatica". Anatomical variants of the pelvic girdle muscles and functional factors, including muscle spasm and pelvic instability, may contribute to development of deep gluteal syndrome, along with neural senescence. Imaging findings primarily relate to the presence of sciatic neuritis and peri-sciatic pathology, including neural compression and peri-neural adhesions or fibrosis. This imaging review describes the causes, magnetic resonance imaging and ultrasound imaging findings and imaging-guided treatment of pelvic neural causes of chronic buttock pain and sciatica.

Extending the straight leg raise test for improved clinical evaluation of sciatica: validity and diagnostic performance with reference to the magnetic resonance imaging.

BACKGROUND: The straight leg raise test (SLR) is one of the most utilized and studied physical tests in patients with low back pain (LBP) for the detection of lumbar disc herniation (LDH), showing high sensitivity and heterogeneous or low specificity. The high incidence of asymptomatic 'pathologic' findings in the magnetic resonance imaging (MRI) scans may cause verification bias to these results. We studied an extended SLR (ESLR) by adding location-specific structural differentiation movements (hip internal rotation or ankle dorsiflexion) to the traditional SLR for it to better differentiate neural symptoms from musculoskeletal. Previously, the ESLR has shown almost perfect interrater reliability between examiners and ability to detect sciatic patients. In this study, we investigated whether a 'positive' ESLR finding is associated with pathology seen on MRI. METHODS: Forty subjects comprised the study population, 20 in sciatic group and 20 in control group. The ESLR was performed 'blinded' to the subjects. After the ESLR, each subject's lumbar MRI was evaluated. The MRIs were analyzed independently by 2 senior radiologists and a spine specialist clinician. The ESLR and MRI results were cross-tabulated. To obtain the odds ratio (OR) with positive ESLR or SLR results for LDH or nerve root compression (NC), a binary logistic regression analysis with subjects' age, gender, height and weight was performed. ESLR's validity was assessed by combination of interrater agreement and percentage prevalence of both LDH and NC. RESULTS: Of sciatic (ESLR+) patients, 85 % had LDH and 75 % NC in the MRI. Not surprisingly, MRI showed a very high incidence of 'false-positive' findings with the ESLR negative group. The ESLR showed 0.85 sensitivity and 0.45 specificity for LDH and 0.75 sensitivity and 0.50 specificity for NC. A positive result in the ESLR was found to be strongly associated with for both LDH and NC: the OR was 8.0 (p = 0.028) and 5.6 (p = 0.041), respectively. CONCLUSIONS: The ESLR shows high validity in detecting neural symptoms and is strongly associated with pathology seen in the MRI when judged positive. We suggest the use of ESLR in clinical practice as a part of clinical examination, where it may prove to be a valuable tool in detecting patients with sciatic symptoms.

Venous Thromboembolism Manifesting as Sciatica in Two Pregnant Women.

BACKGROUND: Low back pain is a common presentation among pregnant women. CASE: This case report highlights two women who developed excessive low back radicular nerve symptoms during pregnancy as the initial presentation of proximal venous thromboembolism. CONCLUSION: The use of Doppler ultrasound imaging or magnetic resonance imaging is suggested for women presenting with severe clinical symptoms of radicular low back or leg pain in pregnancy to rule out thromboembolism and guide patient management.

Shear Wave Elastographic Investigation of the Immediate Effects of Slump Neurodynamics in People With Sciatica.

OBJECTIVES: Neurodynamic techniques are often used to treat people with sciatica pain, but their mechanical effects on the sciatic nerve are unknown. Shear wave elastography (SWE) has been shown to effectively estimate the stiffness of peripheral nerves in real time. The aim of this study was to use SWE to assess the effects of slump neurodynamics in the sciatic stiffness of people with sciatica. METHODS: Sixteen participants volunteered for this study. The sciatic stiffness of 8 patients with unilateral chronic sciatica and 8 healthy control participants was measured by SWE, with the participants in a prone position and during a dynamic condition (ie, ankle dorsiflexion). These measurements were performed before and immediately after the neurodynamic intervention, which consisted of a static slump position applied to the symptomatic limb of the patients with sciatica and in a randomly chosen limb of the healthy participants. RESULTS: The 8 patients with sciatica included 6 male and 2 female patients, and the 8 healthy control participants included 5 male and 3 female volunteers. Slump neurodynamics resulted in an immediate decrease in the sciatic nerve stiffness of the symptomatic limb in people with sciatica by 16.1% (effect size = 0.65; P = .019). The intervention showed no significant changes in the sciatic nerve stiffness of the healthy participants (effect size = 0.05; P = .754). CONCLUSIONS: Slump neurodynamics have the potential of decreasing the sciatic nerve stiffness in people with sciatica, and this effect can be quantified by SWE, which may provide valuable information for health professionals.

Patients' and clinicians' perspectives on a 'fast-track' pathway for patients with sciatica in primary care: qualitative findings from the SCOPiC stratified care trial.

BACKGROUND: Sciatica is common and associated with significant impacts for the individual and society. The SCOPiC randomised controlled trial (RCT) (trial registration: ISRCTN75449581 ) tested stratified primary care for sciatica by subgrouping patients into one of three groups based on prognostic and clinical indicators. Patients in one group were 'fast-tracked' for a magnetic resonance imaging (MRI) scan and spinal specialist opinion. This paper reports qualitative research exploring patients' and clinicians' perspectives on the acceptability of this 'fast-track' pathway. METHODS: Semi-structured interviews were conducted with 20 patients and 20 clinicians (general practitioners, spinal specialist physiotherapists, spinal surgeons). Data were analysed thematically and findings explored using Normalisation Process Theory (NPT) and 'boundary objects' concept. RESULTS: Whilst the 'fast-track' pathway achieved a degree of 'coherence' (i.e. made sense) to both patients and clinicians, particularly in relation to providing early reassurance based on MRI scan findings, it was less 'meaningful' to some clinicians for managing patients with acute symptoms, reflecting a reluctance to move away from the usual 'stepped care' approach. Both groups felt a key limitation of the pathway was that it did not shorten patient waiting times between their spinal specialist consultation and further treatments. CONCLUSION: Findings contribute new knowledge about patients' and clinicians' perspectives on the role of imaging and spinal specialist opinion in the management of sciatica, and provide important insights for understanding the 'fast-track' pathway, as part of the stratified care model tested in the RCT. Future research into the early referral of patients with sciatica for investigation and specialist opinion should include strategies to support clinician behaviour change; as well as take into account the role of imaging in providing reassurance to patients with severe symptoms in cases where imaging reveals a clear explanation for the patient's pain, and where this is accompanied by a thorough explanation from a trusted clinical expert.

Lumbar disc extrusions reduce faster than bulging discs due to an active role of macrophages in sciatica.

OBJECTIVE: This retrospective observational histological study aims to associate the size and type of disc herniation with the degree of macrophage infiltration in disc material retrieved during disc surgery in patients with sciatica. METHODS: Disc tissue of 119 sciatica patients was embedded in paraffin and stained with hematoxylin and CD68. Tissue samples were categorized as mild (0-10/cm2), moderate (10-100/cm2), and considerable (> 100/cm2) macrophage infiltration. All 119 patients received an MRI at baseline, and 108 received a follow-up MRI at 1-year. MRIs were reviewed for the size and type of the disc herniations, and for Modic changes in the vertebral endplates. RESULTS: Baseline characteristics and duration of symptoms before surgery were comparable in all macrophage infiltration groups. The degree of macrophage infiltration was not associated with herniation size at baseline, but significantly associated with reduction of size of the herniated disc at 1-year post surgery. Moreover, the degree of macrophage infiltration was higher in extrusion in comparison with bulging (protrusion) of the disc. Results were comparable in patients with and without Modic changes. CONCLUSION: Macrophage infiltration was positively associated with an extruded type of disc herniation as well as the extent of reduction of the herniated disc during 1-year follow-up in patients with sciatica. This is an indication that the macrophages play an active role in reducing herniated discs. An extruded disc herniation has a larger surface for the macrophages to adhere to, which leads to more size reduction.

Deep gluteal syndrome is defined as a non-discogenic sciatic nerve disorder with entrapment in the deep gluteal space: a systematic review.

PURPOSE: Clinicians are not confident in diagnosing deep gluteal syndrome (DGS) because of the ambiguity of the DGS disease definition and DGS diagnostic pathway. The purpose of this systematic review was to identify the DGS disease definition, and also to define a general DGS diagnostic pathway. METHODS: A systematic search was performed using four electronic databases: PubMed, MEDLINE, EMBASE, and Google Scholar. In eligibility criteria, studies in which cases were explicitly diagnosed with DGS were included, whereas review articles and commentary papers were excluded. Data are presented descriptively. RESULTS: The initial literature search yielded 359 articles, of which 14 studies met the eligibility criteria, pooling 853 patients with clinically diagnosed with DGS. In this review, it was discovered that the DGS disease definition was composed of three parts: (1) non-discogenic, (2) sciatic nerve disorder, and (3) nerve entrapment in the deep gluteal space. In the diagnosis of DGS, we found five diagnostic procedures: (1) history taking, (2) physical examination, (3) imaging tests, (4) response-to-injection, and (5) nerve-specific tests (electromyography). History taking (e.g. posterior hip pain, radicular pain, and difficulty sitting for 30 min), physical examination (e.g. tenderness in deep gluteal space, pertinent positive results with seated piriformis test, and positive Pace sign), and imaging tests (e.g. pelvic radiographs, spine and pelvic magnetic resonance imaging (MRI)) were generally performed in cases clinically diagnosed with DGS. CONCLUSION: Existing literature suggests the DGS disease definition as being a non-discogenic sciatic nerve disorder with entrapment in the deep gluteal space. Also, the general diagnostic pathway for DGS was composed of history taking (posterior hip pain, radicular pain, and difficulty sitting for 30 min), physical examination (tenderness in deep gluteal space, positive seated piriformis test, and positive Pace sign), and imaging tests (pelvic radiographs, pelvic MRI, and spine MRI). This review helps clinicians diagnose DGS with more confidence. LEVEL OF EVIDENCE: IV.

Clinical and imaging characteristics of patients with extreme low back pain or sciatica referred for spinal injection.

PURPOSE: To analyze the causes of pain, imaging characteristics, and therapeutic effect of spinal injection in patients with extreme low back pain or sciatica. METHODS: We analyzed 381 consecutive patients with extreme low back pain or sciatica visiting our spinal intervention center between January and December 2017. Clinical and imaging characteristics were analyzed. The treatment response, defined as a numerical pain rating scale decrease of ≥ 30%, was measured. Fisher's exact test was performed to identify the association between the injection response and subsequent lumbar surgery rate. RESULTS: The most frequent cause of pain was spinal stenosis, followed by herniated intervertebral disc, facet osteoarthritis, and osteoporotic compression fracture. A herniated intervertebral disc was the most common disorder in patients < 50 years of age, while spinal stenosis was the most common in patients ≥ 50 years of age. Women comprised 66.4% of the study population. The majority of lumbar pathologies occurred below L3/4. Spinal injection was found to be effective in 44.2% of cases. Those who responded to the injection showed a significantly lower rate of lumbar surgery within 6 months (P = 0.004). CONCLUSIONS: Those with extreme low back pain or sciatica had clinical and imaging characteristics similar to those with typical low back pain referred for spinal injection. Spinal injection could be an effective method of pain control for patients with extreme low back pain or sciatica.

Sciatic Nerve Variants in Patients Diagnosed With Sciatica: Is There a Correlation?

PURPOSE: Compression of the sciatic nerve in its path along the piriformis muscle can produce sciatica-like symptoms. There are 6 predominant types of sciatic nerve variations with type 1 being the most common (84.2%), followed by type 2 (13.9%). However, there is scarce literature on the prevalence of sciatic nerve variation in those diagnosed with sciatica. MATERIALS AND METHODS: The charts of 95 patients clinically diagnosed with sciatica who had a magnetic resonance imaging of the pelvis/hip were retrospectively studied. All patients had T1-weighted axial, coronal, and sagittal images. Magnetic resonance imagings were interpreted separately by 2 board-certified fellowship-trained musculoskeletal radiologists to identify the sciatic nerve variant. RESULTS: Seven cases were excluded because of inadequate imaging. Of the remaining 88 patients, 5 had bilateral sciatica resulting in a sample size of 93 limbs. Fifty-two (55.9%) had type 1 sciatic nerve anatomy, 39 (41.9%) had type 2, and 2 (2.2%) had type 3. The proportions of type 1 and 2 variations were significantly different from the normal distribution (P < 0.001), whereas type 3, 4, 5, and 6 variants were not (P = 1.00). CONCLUSIONS: There is strong statistical significance regarding the relationship between sciatic nerve variation and the clinical diagnosis of sciatica. Preoperative magnetic resonance imaging can be considered in sciatica patients to prevent iatrogenic injury in pelvic surgery.

Extrapelvic Sciatic Nerve Endometriosis, the Role of Magnetic Resonance Imaging: Case Report and Systematic Review.

Endometriosis (EN) is a common gynecological condition characterized by the presence of functional endometrium located outside the uterine cavity. Sciatic nerve (SN) is rarely affected by EN. Magnetic resonance imaging allows a direct visualization of the spinal and SN, and it is the modality of choice for the study of SN involvement in extrapelvic EN. We report a case of an endometrioma located in the right SN with a systematic review of the literature.

The relationship of the shear wave elastography findings of patients with unilateral lumbar disc herniation and clinical characteristics.

BACKGROUND: The aim of this study was to find out whether the shear wave elastography (SWE) findings of patients with unilateral lumbar disc herniation (LDH) were related to clinical characteristics. METHODS: For this purpose, the study group included patients (N = 20; 13 male, 7 female) with complaints of unilateral sciatica, with foraminal stenosis caused by one level of LDH (L4-L5 or L5-S1). An gender-and age-matched control group (N = 27; 16 male, 11 female) was included. All the patients were examined on both the axial and longitudinal planes bilaterally at the same level using a convex array probe (1- 6 MHz, Supersonic Imagine, Aix en Provence, France). RESULTS: The sciatic nerve stiffness measured on longitudinal planes of the affected side was significantly higher than unaffected side (p < 0.001) and the control group (P < 0.05). Furthermore, the symptom duration of unilateral LDH is positively correlated with the stiffness the sciatic nerve (r = 0.52, p = 0.019). CONCLUSION: According to these findings, ultrasound imaging can be considered as a useful tool to detect changes in the sciatic nerve due to disc herniation. This technique will have a promising prospect for many patients with unilateral LDH in monitoring stiffness during rehabilitation and before or after surgery.

Sonoelastographic evaluation of the sciatic nerve in patients with unilateral lumbar disc herniation.

OBJECTIVE: The aim of this study was to compare strain elastography (SE) and shear wave elastography (SWE) findings of the sciatic nerve in patients with unilateral lumbar disc herniation (LDH) and healthy control subjects. MATERIALS AND METHODS: The study group included patients with complaints of unilateral sciatica for 3-12 months, with foraminal stenosis due to one level of LDH (L4-L5 or L5-S1). An age- and gender-matched control group was formed of healthy subjects. Evaluations were performed on both the axial and longitudinal planes from the bilateral gluteal region using a 5-9 MHz multifrequency convex probe. RESULTS: There were 40 patients (20 male, 20 female) with a mean age of 43.1 ± 12.7 years in the study group, and 40 healthy subjects (22 male, 18 female) with a mean age of 42.9 ± 10.7 years in the control group (p > 0.05). The sciatic nerve stiffness assessed on both the axial (12.3 ± 3.7 kPA) and longitudinal (14.3 ± 3.8 kPA) planes of the involved side was significantly higher than non-involved side (axial: 6.8 ± 2.1 and longitudinal: 8.3 ± 2.3 kPA) in the patient group (p < 0.001). CONCLUSIONS: Patients with unilateral LDH have increased stiffness of the sciatic nerve compared to healthy control subjects. Although the findings in this preliminary study show that shear wave elastography can detect a change in sciatic nerve stiffness in patients with unilateral LDH, larger studies are required to determine the clinical utility of this technique.

Post-operative extra-spinal etiologies of sciatic nerve impingement.

Sciatica is a highly prevalent cause of morbidity, commonly resulting from intra-spinal pathological processes. Many cases can have extra-spinal etiologies and can be clinically challenging. Certain scenarios should suggest an extra-spinal etiology, particularly total and revision hip arthroplasty, surgical hip dislocation, hip arthroscopy, and surgery in the lithotomy position. We review the post-operative clinical scenarios where sciatic neuropathy may occur, along with the pertinent imaging findings.

Treatment of acute sciatica with transforaminal epidural corticosteroids and local anesthetic: design of a randomized controlled trial.

BACKGROUND: Transforaminal epidural injections with steroids (TESI) are used increasingly for patients with sciatica. However there is much debate about their safety and effectiveness. It is important to identify patients that benefit most from TESI and only few trials have yet evaluated the effects in patients with acute sciatica. METHODS: We describe a prospective, randomized controlled trial (RCT), with the aim to evaluate the hypothesis that TESI plus Levobupivacaine (TESI-plus) added to oral pain medication is more effective compared to pain medication alone or compared to transforaminal injection with a local anesthetic of short duration among patients with acute sciatica. We will recruit a total of 264 patients with sciatica (<8 weeks) caused by a herniated disc, from two clinical sites. Participants are randomly assigned one of three study groups: 1) oral pain medication (control group), 2) oral pain medication and TESI-plus (intervention group one), 3) oral pain medication and transforaminal epidural injection (TEI) with Levobupivaine and saline solution (intervention group two). Primary outcomes are functional status (Roland-Morris Disability Questionnaire), pain intensity for both leg and back, (100 mm visual analogous scale (VAS)), and global perceived recovery (GPR, reported on a 7-point Likert scale, dichotomized into 'recovered' and 'not recovered'). The secondary outcomes are health-related quality of life (EQ5D-5 L) and patient satisfaction (7-point Likert scale). We will also collect information on healthcare utilization and costs, to perform an economic evaluation. All outcomes are measured at three and six weeks, three and six months after randomization. We defined a minimal clinically relevant difference between groups as a difference between both intervention groups and the control group of 20 points for pain (100-point VAS), four points for functional status (24-point RDQ) and a 20% difference on dichotomized GPR (recovered versus not recovered). DISCUSSION: A clinically relevant outcome in favor of TESI-plus implies that future patients with acute sciatica should be recommended TESI-plus within the first few weeks rather than being treated with pain medication alone in order to relieve pain and improve their functioning. In case of a negative result (no relevant differences in outcome between the three study arms), pain medication will remain the mainstay of treatment in the acute stages of sciatica. TRIAL REGISTRATION: Dutch National trial register: NTR4457 (March, 6th, 2014).

Dual lumbar bronchogenic and arachnoid cyst presenting with sciatica and left foot drop.

INTRODUCTION: Spinal bronchogenic cysts are rare findings, with only four cases of lumbar bronchogenic cysts reported in the literature. All of these bronchogenic cysts involved the conus medullaris. We present the first case of a lumbar bronchogenic cyst and arachnoid cyst arising from the cauda equina in a 68-year-old male. Uniquely, this bronchogenic cyst also contained components of an arachnoid cyst. METHODS: Magnetic resonance imaging (MRI) demonstrated a compressive cystic lesion at the level of the L3 vertebra splaying the cauda equina. An L3/L4 laminectomy was performed with marsupialisation of the cyst. RESULTS: Histological examination revealed pseudostratified ciliated columnar epithelium confirming the diagnosis of a bronchogenic cyst, as well as a pleated fibrovascular tissue lined by sparsely spaced small monomorphic arachnoidal cells, indicating an arachnoid cyst. CONCLUSION: We demonstrate that bronchogenic cysts can be successfully treated with marsupialisation.

A diagnostic study in patients with sciatica establishing the importance of localization of worsening of pain during coughing, sneezing and straining to assess nerve root compression on MRI.

PURPOSE: To test whether the localization of worsening of pain during coughing, sneezing and straining matters in the assessment of lumbosacral nerve root compression or disc herniation on MRI. METHODS: Recently the diagnostic accuracy of history items to assess disc herniation or nerve root compression on magnetic resonance imaging (MRI) was investigated. A total of 395 adult patients with severe sciatica of 6-12 weeks duration were included in this study. The question regarding the influence of coughing, sneezing and straining on the intensity of pain could be answered on a 4 point scale: no worsening of pain, worsening of back pain, worsening of leg pain, worsening of back and leg pain. Diagnostic odds ratio's (DORs) were calculated for the various dichotomization options. RESULTS: The DOR changed into significant values when the answer option was more narrowed to worsening of leg pain. The highest DOR was observed for the answer option 'worsening of leg pain' with a DOR of 2.28 (95 % CI 1.28-4.04) for the presence of nerve root compression and a DOR of 2.50 (95 % CI 1.27-4.90) for the presence of a herniated disc on MRI. CONCLUSIONS: Worsening of leg pain during coughing, sneezing or straining has a significant diagnostic value for the presence of nerve root compression and disc herniation on MRI in patients with sciatica. This study also highlights the importance of the formulation of answer options in history taking.

Perisciatic Ultrasound-Guided Infiltration for Treatment of Deep Gluteal Syndrome: Description of Technique and Preliminary Results.

The objective of this study was to describe a perisciatic ultrasound-guided infiltration technique for treatment of deep gluteal syndrome and to report its preliminary clinical results. A mixture of saline (20 mL), a local anesthetic (4 mL), and a corticosteroid solution (1 mL) was infiltrated in the perisciatic region between the gluteus maximus and pelvitrochanteric muscles. Relative pain relief was achieved in 73.7% of the patients, with average preprocedural and postprocedural visual analog scale scores of 8.3 and 2.8, respectively. Fifty percent of patients reported recurrence of discomfort, and the average duration of the therapeutic effect in these patients was 5.3 weeks.

Anatomic Differences in the Sacral Hiatus During Caudal Epidural Injection Using Ultrasound Guidance.

OBJECTIVES: The aim of this study was to clarify differences in the anatomic structure of the sacral hiatus and angle of needle insertion during caudal epidural steroid injection using ultrasound guidance in patients according to sex and age. METHODS: A total of 237 patients with low back pain with or without sciatica were included. Sonograms of the sacral hiatus were obtained, and caudal epidural steroid injection using ultrasound guidance was performed in all patients. The intercornual distance, diameter of the sacral canal, thickness of the sacrococcygeal ligament, optimal angle for needle insertion, and actual angle of needle insertion were measured. RESULTS: Between men and women, significant differences were observed for the intercornual distance (17.7 versus 16.5 mm; P< .01) and thickness of the sacrococcygeal ligament (4.3 versus 3.9 mm; P = .02). In all patients, the thickness of the sacrococcygeal ligament (r= 0.28) and diameter of the sacral canal (r= 0.40) were positively correlated with the optimal angle for needle insertion (P < .01). In women, the thickness of the sacrococcygeal ligament (r = -0.24), diameter of the sacral canal (r = -0.27), optimal angle for needle insertion (r = -0.29), and actual angle of needle insertion (r = -0.18) were negatively correlated with age. In men, only the diameter of the sacral canal was negatively correlated with age (r = -0.30). CONCLUSIONS: We found that the sacral hiatus has anatomic differences between patients of different sexes and ages. Understanding these differences, especially in women, may improve the safety and reliability of caudal epidural steroid injection.