Fig. 47.1
Anatomic overview of lumbar spine – position of needles at the medial branch of the dorsal ramus. (a) medial branch dorsal ramus. (b) intervertebral disc. (c) communicating ramus. (d) sympathetic chain. svn sinuvertebral nerve, ALL anterior longitudinal ligament. * mamillo-accessory ligament
The facet joints are innervated by medial branches of the dorsal ramus from the corresponding level and by the medial branch of the dorsal ramus one level above. So the facet joint L5–S1 is innervated by the dorsal rami L4 and L5.
The medial branch innervates skin ligaments and muscles, whereas at level L5 the medial branch mostly consists of sensory fibers. The lateral branch innervates muscles. The medial branches have to be blocked in the gutter where the superior articular process and the transverse process come together (Fig. 47.1).
The anatomy of the back and the innervation of the posterior compartment are described elsewhere more extensively (see Chaps. 49 and 59).
If the joints become painful, they may cause pain in the low back, abdomen, buttocks, groins, or legs. The lumbar zygapophyseal joints are a potential source of low back pain and referred leg pain.
Introduction: Technique
The technique of lumbar facet denervation was first described by Shealy in 1974. Later several authors modified this technique. Anatomical studies revealed more exactly the place where the block had to be performed. In this chapter, the most common technique will be described using fluoroscopy and bony landmarks. The procedure can be performed in an outpatient setting with the patient awake. Most patients are sufficiently cooperative. Administration of a sedative is rarely necessary. As the innervation of the joint is always from two levels, the procedure must always be done at two levels, in case of pain from two adjacent joints at three levels. The procedure can be performed uni- or bilaterally.
Indications
In the literature there is doubt about the existence of a specific facet syndrome, but in Table 47.1 some signs and symptoms are listed, suggesting pain originating from facet joints.
Table 47.1
Possible signs and symptoms of facet pain in the lumbar region
Back pain with or without irradiation to the groin, buttock, leg, sometimes abdomen |
Pain aggravated by rest in any posture (standing, sitting, laying in bed) |
Pain relieved by movement |
Radiculopathy is absent (no neurological deficit) |
Pain should not radiate below the knee |
Morning stiffness |
Awakening by turning in bed |
Pain on anteflexion and/or rotation of the spine |
Paravertebral tenderness |
Uni- or bilateral pain lasting longer than 3–6 months not reacting on physical therapy and other conservative management could be an indication for percutaneous facet denervation (PFD). In the absence of a specific facet syndrome, most authors advocate to perform a test block prior to a PFD. This test block is a medial branch block or an intra-articular block with local anesthetics. Some authors adjust steroids in order to achieve a longer lasting effect of the test procedure. They believe that the addition of steroids will further reduce any inflammation that may exist within the joint.
Radiological findings per se, such as facet arthritis, are no indication for a PFD (Tables 47.2 and 47.3).
Table 47.2
Contraindications
Sensory loss |
Lack of cooperativeness |
Bleeding disorders or use of anticoagulants |
Signs of local infection |
Signs of local malignancy |
Presence of osteosynthesis material |
Allergy to local anesthetics |
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