Facet blocks and sacroiliac joint injections

The innervation of the cervical facet joints - an anatomical and histological approach

INTRODUCTION

Cervical facet joint pain syndrome accounts for a great amount of cervical pain worldwide. This study aims to provide updated knowledge of cervical facet joint innervation with new anatomical findings.

MATERIALS AND METHODS

Twenty-seven cervical facet joints and their innervating structures were dissected from five halves of three human neck specimens. Histologic staining was used to confirm that the samples were nervous tissues, and all samples were documented with photography.

RESULTS

Histology: Thirty-six assumed facet joint branch samples were obtained and stained. Twenty-two of these were confirmed to be nervous tissue. Therefore, 61% of the samples were identified as facet joint branches. Of all samples, 28% were not nerves. Dissection: At least one medial branch was clearly identified at each dissected cervical level. At some cervical levels, more than one medial branch was found. Anatomical differences, such as a plexus-like innervation in the high cervical region, were observed. Direct facet joint branches were also discovered. These branches originate directly from the dorsal root of the spinal nerve and were independent from medial branches during their direct pathway toward the facet joint.

CONCLUSION

Direct cervical facet joint branches were identified and a more diverse innervation pattern than previously described of the cervical facet joints was found. This article is protected by copyright. All rights reserved.

Comparative study of imaging and histology of sacroiliac joint in normal rats based on IVIM-DWI and DCE-MRI

Background

Currently, few studies have described the relationship between functional MRI findings and histology of normal sacroiliac joint (SIJ). Besides, due to the difficulties in access to SIJ, authentic animal models are important in providing opportunities for quantitative parameter extraction on imaging.

Aims

This study aimed at exploring the parameters of Intravoxel Incoherent Motion Diffusion-Weighted Imaging (IVIM-DWI) and Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) and comparing them with the histology of the SIJ in normal rats with different ages.

Methods

A total of thirty 7-week-old male Wistar rats were included in the study. The parameters of IVIM-DWI and DCE-MRI in the bone marrow and the joint space of SIJ were measured at 8, 13, 18, 23, 28, and 33 weeks. The histological analysis of the SIJ was examined using light microscopy. One-way ANOVA was used for statistical analysis.

Results

The D values in the sacral and iliac bone marrow of normal rats decreased with an increase in age. One-way ANOVA analysis indicated a significant difference in D values in different age groups (P<0.005). The normal values of D*, f, Fenh (%), Senh (%/s) in the sacral bone marrow, the iliac bone marrow, and the joint space in SIJ of normal rats were obtained. The results showed that in the six groups of rats of different ages, the histology of the SIJ surface was smooth and clear, the cartilage cells were intact, and no thickening or pannus formation was observed.

Conclusions

This study obtained the IVIM-DWI and DCE-MRI parameters of the sacral and iliac bone marrow and the synovial area of the joint space in normal rats. The parameters in normal rats can be used in future research to compare to similar parameters in animal models or patients with SIJ diseases. This study serves as a guide for future research in SIJ diseases.

A cadaveric study on sacroiliac joint injection

The scope of this study was to explore the possibility as well as the feasibility of sacroiliac joint injection following simple X-ray clip location. For the cadaveric study, 10 fixed sacroiliac joint (SIJ) sectional specimens, 4 dried cadaveric pelvises and 21 embalmed adult cadaveric pelvises were dissected, followed by an injection of contrast agent into the joint. The irrigation of the agent was observed through CT scanning. For the radiologic study, 188 CT scans of ankylosing spondylitis patients (143 male, 45 female) were collected from 2010 to 2012, in Nanfang Hospital. What was measured was (1) Distance between the posterior midline and sagittal synovium; (2) Length of the sagittal synovium; (3) Distance between the midpoint of the sagittal synovium and posterior superior iliac spine; and (4) Distance between the superficial skin vertical to the sagittal synovium point were measured. For the practice-based study: 20 patients (17 males and 3 females) with early ankylosing spondylitis, from Nanfang Hospital affiliated with Southern Medical University were recruited, and sacroiliac joint unguided injections were done on the basis of the cadaveric and radiologic study. Only the inferior 1/3(rd) portion parallel to the posterior midline could be injected into since the superior 2/3(rd) portion were filled with interosseous ligaments. Thirteen of the 20 patients received successful injections as identified by CT scan using the contrast agent. Sacroiliac joint injection following simple X-ray clip location is possible and feasible if the operation is performed by trained physicians familiar with the sacroiliac joint and its surrounding anatomic structures.

Efficacy of therapeutic fluoroscopy-guided lumbar spine interventional procedures

PURPOSE

To evaluate the benefit of fluoroscopy-guided lumbar spine interventional procedures in treatment of low back pain.

METHODS

This prospective descriptive study was performed on 60 patients with back/radicular pain after showing no improvement with conservative treatment.

RESULTS

One hundred and two injection sessions were done (average 1.7 injection per patient). Caudal and lumbar transforaminal injections were effective in 55.9% and 78.5%, respectively. Facet and sacroiliac interventions were effective in 28.3% and 10%, respectively. Complications occurred in 20% of the procedures.

CONCLUSION

Lumbar injections improved pain/disability related to discogenic lumbar spinal diseases. Efficacy of facet and sacroiliac injections is limited.

Transverse morphology of the sacroiliac joint: effect of angulation and implications for fluoroscopically guided sacroiliac joint injection

OBJECTIVE

Effects of angulation of computed tomography (CT) reconstruction plane on sacroiliac (SI) joint morphology were studied, and factors influencing the approach to fluoroscopically guided SI joint injection were assessed.

DESIGN AND PATIENTS

CT scans of pelvises were reformatted on 41 subjects, aged 51.7 (+/-15.1) years. Transverse images were reconstructed at the caudal 3 cm of the SI joint tilting plane of reconstruction from -30 degrees to +30 degrees at 15 degrees increments. Anteroposterior diameter of joint (depth), angle from sagittal plane (orientation angle), and distance from skin were measured. Joint contour was classified, and presence of bone blocking access to the joint was recorded. Comparison between angles were analysed by t-test. Relationships between variables were assessed by a Pearson correlation test.

RESULTS

Depth was shorter with angulation in the inferior direction (P<0.01). Orientation angle increased with superior angulation (P<0.01). Distance from skin increased (P<0.01) with angulation in either direction. Joint contour was significantly different from baseline at each angle (P<0.001) but highly variable. Inferior angulation resulted in interposition of ilium between skin and SI joint, and superior angulation caused bone block due to the lower sacrum. None of these features was identified without tilting of the reconstruction plane, and effects were more pronounced with steeper angulation.

CONCLUSION

Angulation of the reconstruction plane considerably affects the appearance of the sacroiliac joints. By shortening joint depth, an inferiorly directed approach to SI joint injection may make fluoroscopic guidance easier, although associated bony interposition can prevent access to the synovial compartment. A superiorly directed approach is more likely to have adverse effects.

Interventional radiology and the musculoskeletal system

Imaging-guided interventional procedures are becoming increasingly important in clinical rheumatology, since arthrocentesis of peripheral joints and the spine, as well as soft tissue injections, have a high rate of para-articular localisation when performed as blind techniques. Ultrasound-guided needle placement is the method of choice for interventional procedures on peripheral joints and for soft tissue injections. Fluoroscopy and computed tomography (CT) are not recommended for these indications due to the application of ionising radiation and the high procedural effort. By contrast, CT and magnetic resonance imaging are preferred for a variety of percutaneous procedures on the spine and sacroiliac joints. The increasing use of these methods for interventional purposes should improve both technical and procedural quality, thus ensuring cost-effectiveness and patient safety.