Ultrasound-guided radiofrequency neurotomy in cervical spine: sonoanatomic study of a new technique in cadavers
To develop an ultrasound-guided technique for radiofrequency (RF) cervical medial branch neurotomy and to validate the accuracy of this new method. Five non-embalmed, fresh cadavers were used; three male and two female cadavers with a median age at death of 67.2 years (range 50-84 years). This study was conducted in two parts. First, two of the cadavers were used to define the sonographic target point for RF cervical medial branch neurotomy using high-resolution ultrasound (12 to 5 MHz). The needles were guided to five consecutive cervical medial branches in the cadavers under ultrasound guidance. Subsequently, the position of the ultrasound-guided needle was verified using C-arm fluoroscopy. Ultrasound-guided RF neurotomy was performed to the C5 medial branches in all five cadavers. In the three cadavers not used in the first part of the study, ultrasound-guided RF neurotomy without C-arm fluoroscopic confirmation was performed to the C3-C7 medial branches. The accuracy of neurotomy was assessed by pathological examination of the cervical medial branches obtained through cadaver dissection. In all five cadavers, the sonographic target point was identified in all C3-C7 segments with the 12 to 5 MHz linear transducer. In all 20 needle placements for the first and second cadavers, C-arm fluoroscopy validated proper needle tip positions. In all five cadavers, successful neurotomy was pathologically confirmed in 30 of 34 cervical medial branches. Ultrasound-guided cervical medial branch neurotomy was successfully performed in 30 of 34 cervical medial branches in five cadavers. However, before eliminating fluoroscopic validation of final needle tip positioning, the technique should be validated in symptomatic patients.
- [Show abstract] [Hide abstract] ABSTRACT: The purpose of this study was to describe a technique using ultrasound guidance to perform thoracic facet joint injections. A single examiner used ultrasound to localize paired thoracic facet joints from T1-2 through T10-11 on a fresh frozen cadaveric specimen. This was done using a 2- to 5-MHz curvilinear transducer over the target facet in the sagittal plain with the cadaver in the prone position. Target facets were identified using the most inferior rib as a starting point and scanning medially toward its axial attachment and further medially and slightly superior over the most caudal thoracic facet (T11-12). Subsequent ipsilateral facet joints were identified by simply moving the transducer superiorly in the sagittal plain until the next cephalad facet was encountered. After identification, injections were performed using a long-axis or "in-line" approach with continual visualization of the needle into each facet joint. After needle placement, computed images were obtained from a fluoroscopy machine capable of 3-dimensional reconstruction to assess the location of the needle tips. After this, 0.5 mL of an iodinated contrast agent was injected, and another 3-dimensional reconstruction was performed to assess the location of the injected agent. A senior radiology resident reviewed the computed images in coronal, axial, and sagittal planes. Accuracy was determined in terms of contrast location, graded as either intra-articular or extra-articular. Sixteen (80%) of 20 injections performed showed intra-articular contrast spread. We describe a relatively feasible technique for performing thoracic facet joint injections using ultrasound guidance. Further verification of this technique, and modification if applicable, should be performed before directly applying this technique in a clinical practice setting.0Comments 6Citations
- [Show abstract] [Hide abstract] ABSTRACT: The patient with neck pain may pose a diagnostic dilemma for the treating physician. As with other areas of medicine, imaging is guided by the history and physical examination. The steady advance of 3-dimensional, functional, and nuclear medicine studies make it increasingly important that the ordering physician be aware of the potential benefits and disadvantages of imaging options. This article reviews the current literature on imaging for the patient with neck pain, illustrates several imaging abnormalities, and discusses the workup of commonly seen patient populations.0Comments 3Citations
- [Show abstract] [Hide abstract] ABSTRACT: Cervical medial branch blocks are commonly performed for the diagnosis and treatment of head, neck, and shoulder pain. Intermittent fluoroscopy is widely used for needle positioning and visualization of contrast distribution before medication injection. The purpose of this study was to examine the use of ultrasound as an alternative imaging technique to block the third occipital nerve and the C3 to C6 medial branches. The study involved 2 phases with a total of 53 patients. The purpose of phase 1 was to assess the reliability of needle positioning using an ultrasound target corresponding to the middle of the bony contour of the articular pillar. Twenty patients undergoing 46 cervical medial branch blocks between C3 and C6 were recruited, and the needle tip position was graded on a 3-point scale based on its proximity to the centroid on lateral radiograph. In phase 2, 50 patients undergoing 163 levels were recruited. Using ultrasound guidance, each of the targeted levels was injected with 0.3 mL of a 1:1 mixture of local anesthetic and contrast agent. A blinded assessor reviewed contrast distribution in the anteroposterior and lateral radiograph views. In phase 1, all needle tips were positioned on the articular pillars; furthermore, 80.1% were located in the middle 2 quarters of the latter. In phase 2, the contrast was found to cover the appropriate level in 94.5% of cases, and no complications were noted. The incidence of aberrant spread to adjacent levels (13.5%) was similar to that reported with fluoroscopy. Ultrasound guidance offers a reliable alternative to fluoroscopy for third occipital nerve and C3-C6 cervical medial branch blocks. Further studies are required to validate the clinical efficacy of our technique.0Comments 24Citations