A particular form of septic arthritis: Septic arthritis of facet joint

Septic arthritis of the facet joint is also a severe vertebral infection: A multicenter retrospective study of 65 patients

OBJECTIVE

Septic arthritis of the Facet Joints (SAFJ) is a rare condition. Little data has been published on the subject. We aimed to describe the clinical, biological and imagery presentations, as well as the course of this rare infection.

METHODS

We included patients hospitalized between January 1st, 2016 and December 31th, 2019, in the Departments of Infectious Diseases or Rheumatology in 5 French centres in the CRIOGO network. We defined septic arthritis according to Newman's criteria and facet joint arthritis using imagery.

RESULTS

Sixty-five patients were included, predominantly males (64.6%), with a mean age of 68.1 years. The mean time to diagnosis was 25.0 days. The principal symptoms at diagnosis were acute back pain (95.2%) and fever (76.9%). Neurological symptoms were present for 60.7% of the patients, including 16.4% motor deficit or cauda equina syndrome. SAFJ was located on the lumbosacral spine (73.4%) and was rarely multifocal (4.7%). Bacteriological identification was performed by blood cultures in 84.4% of the cases, and the pathogen was mainly Staphylococcus aureus (49.2%). Infective endocarditis was present for 26.9% of patients assessed by echocardiography. On MRI, soft tissue abscess or inflammation, epiduritis and epidural abscess were present in 87.1%, 66.7% and 33.9% of cases, and the pathogen was significantly more frequently Staphylococcus aureus. Mortality reached 9.2%, 18.5% and 23% at one, two, and three years respectively.

CONCLUSION

SAFJ is a rare but severe disease. Microbiological diagnosis is primarily made on blood cultures, and S. Aureus was the main pathogen. Our results highlight the fact that SAFJ is associated with high morbidity and mortality, and with infective endocarditis.

Septic arthritis of the cervical facet joint: Clinical report and review of the literature

BACKGROUND

Facet joint septic arthritis (FJSA) is an uncommon cause of neck pain, most frequently occurring in the lumbosacral spine. Cervical facet joint septic arthritis is particularly rare. Symptoms typically include spinal or paraspinal pain and tenderness, with severe infections potentially causing neurological impairments. This condition can progress to discitis and osteomyelitis. High clinical suspicion is required for accurate diagnosis and timely treatment.

OBJECTIVE

To present the first known case of cervical spine FJSA caused by Moraxella species and provide an updated narrative review of cervical spine FJSA.

METHODS

A case study of a 66-year-old male with cervical spine FJSA caused by Moraxella osloensis is detailed. Additionally, a librarian-assisted literature search was conducted on MEDLINE Pubmed, filtering for adult human trials and including various study types, resulting in the inclusion of 9 relevant manuscripts.

RESULTS

The patient's symptoms included neck, right upper thoracic, and periscapular pain, with episodes of numbness and tingling. MRI revealed septic arthritis at the C7-T1 facet joint and associated osteomyelitis. Cultures identified Moraxella osloensis as the causative agent. The patient was successfully treated with antibiotics and experienced significant symptom improvement. Literature review highlights that Staphylococcus aureus is the most common causative agent of cervical FJSA, with diagnosis typically involving MRI and culture tests. Treatment generally includes long-term antibiotics, with some cases requiring surgical intervention.

CONCLUSIONS

This report underscores the need for high clinical suspicion in diagnosing FJSA and highlights the importance of early intervention. It documents the first known case of cervical spine FJSA caused by Moraxella osloensis, contributing valuable information to the limited literature on this rare condition.

Septic Arthritis of the Spinal Facet Joint: Review of 117 Cases

Background

Septic arthritis of the spinal facet joints is increasingly recognized in the era of magnetic resonance imaging, but its epidemiology, clinical features, management, and prognosis are ill-defined.

Methods

We review 101 previously published cases and report 16 cases occurring at our institutions between 2006 and 2018.

Results

Most patients presented with fever (60%) and back or neck pain (86%). Radiation into the hip, buttock, or limb was present in 34%. The lumbosacral vertebral segments were involved in 78% of cases. Most cases (64%) were due to Staphylococcus aureus. Bacteremia was present in 66% and paraspinal muscle abscesses in 54%. While epidural abscesses were present in 56%, neurologic complications were seen in only 9%, likely because most abscesses arose below the conus medullaris. Neurologic complications were more common with cervical or thoracic involvement than lumbosacral (32% vs 2%, P < .0001). Extraspinal infection, such as endocarditis, was identified in only 22% of cases. An overall 98% of patients survived, with only 5% having neurologic sequelae.

Conclusions

Septic arthritis of the facet joint is a distinct clinical syndrome typically involving the lumbar spine and is frequently associated with bacteremia, posterior epidural abscesses, and paraspinal pyomyositis. Neurologic outcomes are usually good with medical management alone.

Imaging assessment of spine infection

This article comprehensively reviews current imaging concepts in spinal infection with primary focus on infectious spondylodiscitis (IS) as well as the less common entity of facet joint septic arthritis (FSA). This review encompasses the multimodality imaging appearances (radiographs, CT, MRI, and nuclear imaging) of spinal infection-both at initial presentation and during treatment-to aid the radiologist in guiding diagnosis and successful management. We discuss the pathophysiology of spinal infection in various patient populations (including the non-instrumented and postoperative spine) as well as the role of imaging-guided biopsy. We also highlight several non-infectious entities that can mimic IS (both clinically and radiologically) that should be considered during image interpretation to avoid misdiagnosis. These potential mimics include the following: Modic type 1 degenerative changes, acute Schmorl's node, neuropathic spondyloarthropathy, radiation osteitis, and inflammatory spondyloarthropathy (SAPHO syndrome).

Fungal Arthritis of a Lumbar Facet Joint Because of Candida albicans: A Case Report

CASE

A 73-year-old man who was treated in our hospital for pyelonephritis because of left ureteral stones and fungemia was referred to our orthopaedic department for persistent right lower-back pain. Magnetic resonance imaging and computed tomography findings showed pyogenic arthritis of the right L4/5 facet joint with a paraspinal muscle abscess. Based on cultures of samples aspirated from the lesions, we diagnosed the patient with fungal arthritis of the lumbar facet joint. We treated him conservatively with an antifungal agent for a year, and the infection resolved.

CONCLUSION

This is the first report of hematogenous fungal arthritis of a lumbar facet joint.

A Rare Cause of Low Back Pain: A Challenging Diagnosis

One of the rarest causes of low back pain is septic arthritis of a lumbar facet joint. We report the case of a 92-year-old diabetic woman with a history of four days of back pain, dysuria, and fever. Due to a sudden worsening of lumbar pain, she went to the emergency department. Physical exam revealed pain with pressure over the D12 vertebral apophyses and the lower-left paraspinal musculature. Laboratory data showed a normochromic normocytic anemia with a hemoglobin of 9.3 g/dL, white cell count of 14.61x10e3/µL (83.1% neutrophils), serum creatinine 1.46 mg/dL and C-reactive protein of 32.11 mg/dL. In urinalysis, nitrites and leukocyturia were identified. CT scan showed an acute D12 fracture and fat stranding at L5, with no irregularities in the discs or in other lumbar spaces. Escherichia coli was isolated in blood culture. Lumbar MRI confirmed the diagnosis of septic arthritis of an L5-S1 facet joint and L5 vertebrae osteomyelitis. The patient was successfully treated with intravenous ceftriaxone for eight weeks. As far as we know, this is the second report of septic arthritis of the facet joint caused by Escherichia coli.

Preclinical models of vertebral osteomyelitis and associated infections: Current models and recommendations for study design

Spine-related infections, such as vertebral osteomyelitis, discitis, or spondylitis, are rare diseases that mostly affect adults, and are usually of hematogenous origin. The incidence of this condition has gradually risen in recent years because of increases in spine-related surgery and hospital-acquired infections, an aging population, and intravenous (IV) drug use. Spine infections are most commonly caused by Staphylococcus aureus, while other systemic infections such as tuberculosis and brucellosis can also cause spondylitis. Various animal models of vertebral osteomyelitis and associated infections have been investigated in mouse, rat, chicken, rabbit, dog, and sheep models by hematogenous and direct inoculation in surgery, each with their strengths and limitations. This review is the first of its kind to concisely analyze the various existing animal models used to reproduce clinically relevant models of infection. Spine-related infection models must address the unique anatomy of the spine, the avascular nature of its structures and tissues and the consequences of tissue destruction such as spinal cord compression. Further investigation is necessary to elucidate the specific mechanisms of host-microbe response to inform antimicrobial therapy and administration techniques in a technically demanding body cavity. Small-animal models are not suitable for large instrumentation, and difficult IV access thwarts antibiotic administration. In contrast, large-animal models can be implanted with clinically relevant instrumentation and are resilient to repeat procedures to study postoperative infection. A canine model of infection offers a unique opportunity to design and investigate antimicrobial treatments through recruitment a rich population of canine patients, presenting with a natural disease that is suitable for randomized trials.

Pyogenic Lumbar Facet Joint Infection with Foot Drop

Pyogenic facet joint infection (PFJI) is a relatively rare spinal infection. Clinical suspicion of this condition is a key for diagnosis. We report a case of PFJI which required decompression surgery for severe neurological dysfunction. The patient was a 44-year-old woman who had a previous history of orthotic therapy for idiopathic scoliosis. The patient was admitted to our hospital with a history of two days of high fever and severe low back pain. There was no neurologic deficit, and blood tests revealed high levels of inflammatory markers. There was a slight amount of fluid that had collected at L4/5 facet joint in lumbar MRI. She was admitted for examination and treatment of fever of unknown origin and low back pain. Antibiotic treatment started the day after hospitalization since the first report of the blood culture taken upon admission tested positive to gram-positive cocci. As low back pain and fever persisted, an MRI was taken again on the fifth day of hospitalization. Repeated MRI showed fluid extension from the left facet joint to paravertebral muscles and epidural space. She was diagnosed with PFJI, and facet joint puncture was performed. At this time, it became clear that she had foot drop on the right, the contralateral side of the PFJI. She underwent irrigation, debridement, and partial laminectomy. Methicillin-sensitive Staphylococcus aureus (MSSA) was detected in blood cultures at the time of hospitalization, in the puncture fluid and tissue collected during surgery. The patient recovered completely from foot drop after the operation and a three-month course of antibiotics. As the imaging findings may be inadequate in the early stages of onset and PFJI potentially causes neurologic deficit such as foot drop, neurological findings need to be carefully observed even after hospitalization and one should reexamine the MRI if symptoms or clinical findings did not improve or were aggravated.

Differential Diagnosis of Facet Joint Disorders

Spinal pain due to facet joint disease is difficult to diagnose since the clinical history and physical examination findings are usually nonspecific. Facet joint disorders have a wide range of causes and, because of the potential for chronic back pain and disability, an accurate diagnosis is essential. The most frequent cause of pain in facet joints is osteoarthritis, which can be assessed at radiography, CT, or MRI. Ganglion and synovial cysts of the facet joints can cause compressive symptoms of adjacent structures, especially radiculopathy, lower back pain, and sensory or motor deficits. In ankylosing spondylitis, imaging findings of the facet joints are useful not only for diagnosis but also for monitoring structural changes. In septic arthritis of the facet joints, an early diagnosis at MRI is essential. Gout and metabolic diseases are best evaluated at dual-energy CT, which allows the depiction of crystals. Traumatic dislocations of facet joints are usually unstable injuries that require internal reduction, fixation, and fusion and can be well assessed at CT with three-dimensional reconstructions. Facet joint neoplasms like osteoid osteoma, plasmacytoma, tenosynovial giant cell tumor, and osteochondroma are best evaluated at CT or MRI. The authors provide an overview of key imaging features of the most common facet joint disorders along with anatomic tips and illustrative cases. Acknowledging key imaging findings for the differential diagnosis of facet joint disorders plays a crucial role in the diagnostic accuracy and proper treatment approach for such entities. Online supplemental material is available for this article. ^©RSNA, 2021.

Isolated septic facet joints: an underdiagnosed distinct clinical entity

OBJECTIVES

We review a series of isolated septic facet joints (ISFJ) that present as a distinct clinical entity compared with spondylodiscitis. We aim to raise awareness that septic facet joints are not a rare entity in the era of modern imaging.

METHODS

We reviewed 353 patients with confirmed spine infections from 2008 to 2017. Of the 353 cases, there were 152 septic facet joints based on MR imaging. Sixty-two presented as ISFJ without evidence of spondylodiscitis and were reviewed.

RESULTS

Patients were predominantly male 38/62 (61%). The mean age was 56.7 years. Onset of back pain was more acute compared with spondylodiscitis and usually unilateral. The distribution was as follows: 6 cervical, 12 thoracic, and 44 lumbar facets. The majority of ISFJ, 53/62 (85%), were associated with an epidural abscess (EDA) 53/62. The cervical and thoracic EDA required surgical decompression more frequently than lumbar; 100%, 75%, and 53% respectively. Pathogen was identified in 59/62 (95%) cases. Most cases were associated with bacteremia 50/62 (81%). Seven ISFJ were introduced iatrogenically. All iatrogenic ISFJ required surgical decompression.

CONCLUSION

Septic facet joints are not rare, but frequently overlooked as the origin of an epidural abscess. The majority of cases are hematogenously seeded and associated with bacteremia. Surgical decompression is frequently required secondary to the high incidence of associated epidural abscess. Iatrogenic septic facet joints are rare but associated with significant morbidity. From a clinical standpoint, it is helpful to delineate the origin of EDA as either secondary to spondylodiscitis or SFJ.

Spinal Infections: An Update

Spinal infection poses a demanding diagnostic and treatment problem for which a multidisciplinary approach with spine surgeons, radiologists, and infectious disease specialists is required. Infections are usually caused by bacterial microorganisms, although fungal infections can also occur. The most common route for spinal infection is through hematogenous spread of the microorganism from a distant infected area. Most patients with spinal infections diagnosed in early stages can be successfully managed conservatively with antibiotics, bed rest, and spinal braces. In cases of gross or pending instability, progressive neurological deficits, failure of conservative treatment, spinal abscess formation, severe symptoms indicating sepsis, and failure of previous conservative treatment, surgical treatment is required. In either case, close monitoring of the patients with spinal infection with serial neurological examinations and imaging studies is necessary.

Septic arthritis of the lumbar facet joint. Case and literature review

Septic Arthritis of the facet joint (SAFJ) is an uncommon but severe condition of the spine with only 61 cases published to date. Diagnosis is notoriously difficult and can take several months which can lead to significant delays in treatment. We report a case of a 52-year-old female with 2-month history of back pain diagnosed with septic arthritis of the left lumbar L4/5 facet joint and associated epidural abscess. She presented with no fevers, normal neurological examination and normal blood parameters posing a diagnostic challenge. In this report we conclude normal inflammatory markers cannot be used as exclusion criteria for the disease. We also review the body of literature to summarise the key features of the condition to assist clinicians in its diagnosis.

Acute medullar compression secondary to a septic arthritis of a thoracic facet joint: a case report and review of literature

Introduction

Septic arthritis of a facet joint (SAFJ) is a rare entity and frequently underdiagnosed. It is most frequently localised in the lumbar segment.

Case presentation

A 48-year-old woman presented at our emergency room with a chief complaint of lumbar pain and perineal hypoesthesia. An urgent lumbar Magnetic Resonance Imaging (MRI) was performed showing no signs of compressive pathology. Intravenous painkillers were administered improving her clinical symptoms, so she was discharged from the emergency department to be followed at our out-patient clinic. After 12 h, the patient presented again referring an acute loss of strength in her lower limbs and paresthesias at a T10 sensitive level. Due to the severity of the symptoms, we performed an urgent dorsal MRI that showed a septic arthritis of the left T8-T9 facet joint and an epidural abscess causing a medullar compression. Blood cultures were performed before surgical treatment. An urgent laminectomy of T8 and debridement of the abscess were performed. Intraoperative microbiology and blood cultures were positive for Streptococcus constellatus. After surgery, the patient presented a progressive improvement of her symptomatology.

Discussion

Physicians should have in mind and rule out this clinical entity to avoid severe consequences that a misdiagnosed SAFJ could develop.

Cervical facet joint septic arthritis: a real pain in the neck

A 64-year-old man with a complex medical history and previous cervical arthritis with discectomy presents with a 2-day history of neck and lower back pain and shortness of breath, associated with left-sided muscle weakness. He has a fever with severe sepsis causing acute renal failure. MRI spine shows evidence of left cervical facet joint septic arthritis at C6-T1. He required 6 weeks of intravenous antibiotics and intensive support with ventilation and haemofiltration. After completion of antibiotics, he made a full recovery and regained neurological function before discharge.

Infections of the Spine

Pyogenic infections of the bony spinal column and the intervertebral discs are on a steady rise in an aging western population. Despite advanced medical imaging, this clinical entity of devastating consequences if missed, still presents a diagnostic conundrum and is plagued by an unacceptably long diagnostic delay. The aim of this article is to raise awareness of the heterogeneity of spinal infections paralleling the complex structure of the spinal column and neighboring soft tissues. Emphasis is placed on the clinical presentation and management of septic facet joints and psoas muscle abscesses associated with lumbar spondylodiscitis.

Unusual case of paediatric septic arthritis of the lumbar facet joints due to Kingella kingae

A 32-month-old boy presented with febrile limping that had developed over 6days, associated with right lumbosacral inflammatory swelling. Magnetic resonance imaging (MRI) showed joint effusion of the right L5-S1 zygapophyseal joint, complicated by destructive osteomyelitis of the L5 articular process and paraspinal abscess. Surgery was decided to evacuate the fluid accumulation and rule out differential diagnoses. The diagnosis of septic arthritis of the facet joint was confirmed intraoperatively; real-time quantitative PCR analysis identified Kingella kingae. This is the first substantiated paediatric case of zygapophyseal joint septic arthritis due to K. kingae. K. kingae is the most common pathogen responsible for invasive osteoarticular infection in children under 4years of age. Since empiric antibiotics are effective in early stages, physicians should consider the possibility of spinal infections due to K. kingae when a limping child under 4years of age presents with a fever.

Septic arthritis of the facet joint

OBJECTIVE

Septic arthritis of the facet joint is a rare clinical entity. We report 11 cases of facet joint infections diagnosed in our institution.

PATIENTS AND METHOD

Patients were identified via the computerized patients record (PMSI). Their features were collected and compared with published data.

RESULTS

The clinical symptoms are similar to those of infectious spondylodiscitis: back pain with stiffness (11/11), fever (9/11), radicular pain (5/11), and asthenia. Ten patients presented with lumbar infection and 1 with dorsal infection. An inflammatory syndrome was observed in every case. A rapid access to spine MRI allowed making the diagnosis in every case, and assessing a potential extension of infection (epidural extension 5/11, paraspinal extension 5/11). Blood culture (8/11) or culture of spinal samples allowed identifying the causative bacterium in every case and adapting the antibiotic treatment. The bacteria identified in our series were different from previously reported ones, with less staphylococci. The origin of the infection was found in 4 cases. Another localization of infection was observed in 4 cases. The outcome was favorable with medical treatment in 10 cases. An abscess was surgically drained in 1 case. None of our patients presented with neurological complications, probably because of the rapid diagnosis.

CONCLUSION

Assessing the facet joint is essential in case of inflammatory back pain, and the radiologist must be asked to perform this examination.

Effect of machined interfacet allograft spacers on cervical foraminal height and area

OBJECT

Iatrogenic foraminal stenosis is a well-known complication in cervical spine surgery. Machined interfacet allograft spacers can provide a large surface area, which ensures solid support, and could potentially increase foraminal space. The authors tested the hypothesis that machined interfacet allograft spacers increase cervical foraminal height and area.

METHODS

The C4-5, C5-6, and C6-7 facets of 4 fresh adult cadavers were exposed, and the cartilage was removed from each facet using customized rasps. Machined allograft spacers were tamped into the joints. The spines were scanned with the O-arm surgical imaging system before and after placement of the spacers. Two individuals independently measured foraminal height and area on obliquely angled sagittal images.

RESULTS

Foraminal height and area were significantly greater following placement of the machined interfacet spacers at all levels. The Pearson correlation between the 2 radiographic reviewers was very strong (r = 0.971, p = 0.0001), as was the intraclass correlation coefficient (ICC = 0.907, p = 0.0001). The average increase in foraminal height was 1.38 mm. The average increase in foraminal area was 18.4% (0.097 cm(2)) [corrected].

CONCLUSIONS

Modest distraction of the facets using machined interfacet allograft spacers can increase foraminal height and area and therefore indirectly decompress the exiting nerve roots. This technique can be useful in treating primary foraminal stenosis and also for preventing iatrogenic foraminal stenosis that may occur when the initially nonlordotic spine is placed into lordosis either with repositioning after central canal decompression or with correction using instrumentation. These grafts may be a useful adjunct to the surgical treatment of cervical spine disease.

Imaging of spine infection

This article reviews the imaging and relevant clinical details of infection of the extradural spine. Spine infections are increasing in incidence and in frequency of diagnosis. They are clinically important despite their relative rarity, because they may be life-threatening, and because early diagnosis leads to improved outcomes. The focus is on pyogenic spondylodiscitis. The also typically pyogenic conditions of epidural and subdural abscess, facet joint infection, and pyomyositis are discussed. Nonpyogenic, granulomatous infections are also addressed. Magnetic resonance imaging is emphasized. The radiologist's role in performing minimally invasive sampling procedures is highlighted.

Spinal facet joint biomechanics and mechanotransduction in normal, injury and degenerative conditions

The facet joint is a crucial anatomic region of the spine owing to its biomechanical role in facilitating articulation of the vertebrae of the spinal column. It is a diarthrodial joint with opposing articular cartilage surfaces that provide a low friction environment and a ligamentous capsule that encloses the joint space. Together with the disc, the bilateral facet joints transfer loads and guide and constrain motions in the spine due to their geometry and mechanical function. Although a great deal of research has focused on defining the biomechanics of the spine and the form and function of the disc, the facet joint has only recently become the focus of experimental, computational and clinical studies. This mechanical behavior ensures the normal health and function of the spine during physiologic loading but can also lead to its dysfunction when the tissues of the facet joint are altered either by injury, degeneration or as a result of surgical modification of the spine. The anatomical, biomechanical and physiological characteristics of the facet joints in the cervical and lumbar spines have become the focus of increased attention recently with the advent of surgical procedures of the spine, such as disc repair and replacement, which may impact facet responses. Accordingly, this review summarizes the relevant anatomy and biomechanics of the facet joint and the individual tissues that comprise it. In order to better understand the physiological implications of tissue loading in all conditions, a review of mechanotransduction pathways in the cartilage, ligament and bone is also presented ranging from the tissue-level scale to cellular modifications. With this context, experimental studies are summarized as they relate to the most common modifications that alter the biomechanics and health of the spine-injury and degeneration. In addition, many computational and finite element models have been developed that enable more-detailed and specific investigations of the facet joint and its tissues than are provided by experimental approaches and also that expand their utility for the field of biomechanics. These are also reviewed to provide a more complete summary of the current knowledge of facet joint mechanics. Overall, the goal of this review is to present a comprehensive review of the breadth and depth of knowledge regarding the mechanical and adaptive responses of the facet joint and its tissues across a variety of relevant size scales.

The lumbar facet joint: a review of current knowledge: part 1: anatomy, biomechanics, and grading

We present a two-part review article on the current state of knowledge of lumbar facet joint pathology. This first article discusses the functional anatomy, biomechanics, and radiological grading systems currently in use in clinical practice and academic medicine. Facet joint degeneration is presented within the larger context of degenerative disc disease to enable the reader to better understand the anatomical changes underlying facet-mediated lower back pain. Other less-common, but equally important etiologies of lumbar facet joint degeneration are reviewed. The existing grading systems are discussed with specific reference to the reliability of CT and MR imaging in the diagnosis of lumbar facet osteoarthritis. It is hoped that this discussion will stimulate debate on how best to improve the diagnostic reliability of these tests so as to improve both operative and non-operative treatment outcomes.

Escherichia coli septic arthritis of a lumbar facet joint following urinary tract infection

Septic arthritis of a lumbar facet joint is a rare condition. We report the case of a 77-year-old diabetic woman who developed fever and back pain 15 days after she had been diagnosed with a genitourinary infection for which she had received ciprofloxacin. Physical examination showed fever (38°C) and pain on pressure over the lower lumbar spinous vertebral apophyses and over the lower left paraspinal musculature. Investigations showed a white cell count of 8.4×10⁹/l, neutrophils 85.3%, erythrocyte sedimentation rate of 125 mm/h, and C-reactive protein of ≥9 mg/dl. Two blood cultures were both positive for Escherichia coli resistant to ciprofloxacin. There was no growth of pathogens from the urine cultures. Scintigraphy with gallium citrate Ga⁶⁷ showed vertical lower lumbar (L4-L5) radionuclide uptake lateralized to the left. Magnetic resonance imaging of the lumbar spine demonstrated signal changes and alteration of the structure at the left interapophyseal L4-L5 joint, an adjacent small collection of 1cm in diameter, and infiltration of the surrounding soft tissues, which extended to the epidural area, left conjunction hole, and paraspinal muscles. The patient was treated with intravenous cefotaxime and gentamicin and bed rest for 21 days, and recovered. This is the first report of interapophyseal arthritis caused by E. coli.