Pyogenic facet joint infection is a rare but severe infection. The most common complaint on presentation is pain followed by fever, then neurologic impairment. While the lumbar spine is involved in the vast majority of cases presented in the literature, the case presented here occurred in the thoracic spine. The patient was a 48-year-old immune-competent female who presented with left back pain. Magnetic resonance imaging (MRI) indicated a facet effusion, paraspinal abscess, and epidural abscess in the level of 9th-11th thoracic vertebra. On the 6th day of treatment, she presented a neurological disorder and underwent decompressive laminectomy and surgical debridement. We observed immediate improvement as a result of the surgery.
Pyogenic facet joint infection (PFJI) was first described in 1966 and was considered a relatively rare entity [
A 48-year-old female patient presented with left back pain which began 3 days earlier. She described her pain as continuous, severe, precipitated by the smallest movement, and accompanied by fever in more recent days. There was no history of urinary incontinence, spinal trauma, or any other medical problem. She had no history of spine surgery, injections, or drug use. On clinical examination, we found her to be febrile and tachycardic, with the muscular strength in the lower limbs rating 5 according to the manual muscle test (MMT), normal sensations and reflexes, a negative Lasègue’s test, and no pathological meningeal signs. In the first paraclinical test, we observed leukocytosis (1.920/mm3 of blood), neutrophilia (88%), an elevated level of C-reactive protein (23 mg/L), and normal urinalysis. The patient was hospitalized in internal medicine with a diagnosis of unknown fever. As the patient’s condition deteriorated and our clinical suspicions increased, we elected to culture the patient’s blood. In the culture, we discovered methicillin-sensitive
T2-weighted sagittal and axial view showed a facet effusion, paraspinal abscess, and epidural abscess in the level of 10th-11th thoracic vertebra.
The patient was told to continue intravenous antibiotics for 6 weeks. We observed immediate improvement of the paresis and numbness as a result of the surgical decompression. A postoperative MRI taken on the 7th day after surgery showed decompression of the spine and recorded a high signal in the spinal cord, indicating local ischemic changes of the spine at the Th 10 level (Figure
MRI taken on the 7th day after surgery (a) showed decompression of the spine and recorded a high signal in the spinal cord, indicating local ischemic changes of the spine at the Th 10 level ((a) arrow). The MRI taken 3 months after the surgery (b) showed no ischemic change or the facet effusion.
Septic arthritis of the facet joint is a rare condition. Four retrospective reviews of case reports in the literature found that septic arthritis of the facet joint causes 4%–20% of pyogenic spinal infections, 86%–97% of which occur in the lumber spine [
While most cases are thought to occur via hematogenous spread [
The pathophysiology of the epidural abscess is explained because of the narrow facet joint cavity, which facilitates the easy spread of infection to the epidural space (by rupture of the ventral aspect of the joint capsule) and to the paravertebral muscles (by rupture of the posterior aspect of the joint capsule) [
In terms of the location of infection, PFJI of the thorax is very rare. If the epidural abscess occurs by the mechanism listed above, thoracic PFJI may easily accompany the abscess. This is because the thoracic facet is smaller than the lumber facet and the degeneration and thickening of the ligamentum flavum are less severe than that of the lumbar spine; therefore, the capsule may perforate earlier [
There are only two previous reports of thoracic PFJI, excluding iatrogenic cases [
Diagnosing this entity is difficult as it can behave as both a degenerative disease and spondylosis. The facet joint destruction can be seen on simple X-ray and CT images for about 1 month and 1 week after the onset, respectively. MRI is useful for early definitive diagnosis [
The treatment of choice for thoracic PFJI is conservative management with intravenous antibiotics, which is recommended for 4–6 weeks [
The authors declare that they have no conflicts of interest.