Spine Infections

Disease/Disorder

Definition

Spinal infection is a potentially life-threatening condition involving the vertebral body, intervertebral disc, and/or surrounding soft tissues.¹ It can result spontaneously from hematogenous spread, local extension of a nearby infection, or direct inoculation from surgery or injury. ² There are multiple terms that refer to spinal infections, such as discitis, vertebral osteomyelitis, pyogenic spondylitis, septic facet joint, and Pott’s disease. Spondylodiscitis is the correct terminology to describe primary spinal infections, the most common type of spinal infection.²

Etiology

Primary spine infections are hematogenous. The infective organism seeds the vertebral bodies during times of bacteremia. Secondary infections are introduced into the spine via non-hematogenous routes, including trauma, surgery, and injections. Primary discitis in adults is not commonly seen because the disc is avascular. It is seen secondary to vertebral osteomyelitis or is iatrogenic following a discogram, surgery, or inadvertent disc injection during a spinal procedure. In a study of 159 patients treated for spondylodiscitis 35% were secondary infections due to previous open spine surgery, and 65% were primary infections. Primary infections progress more severely and result in significantly higher mortality rate than secondary or postoperative infections (12.5% vs. 1.8%).³

Epidemiology including risk factors and primary prevention

The incidence of spondylodiscitis has increased significantly over the last decade, reaching up to 35.39 cases per 100,000.¹ The increase in number of diagnoses may be due to improved imaging technologies, the growing number of older patients with multiple comorbidities, and spinal procedures. The mean age of diagnosis is 59.6 years old with 56% of patients being men.⁴ Spondylodiscitis is most commonly caused by Staphylococcus aureus (40.3%), followed by Mycobacterium tuberculosis (30.9%), and then by other bacteria including Streptococcus and Enterobacteriaceae spp (28.3%). Fungal and viral etiologies have been reported in <1% of cases.⁴ The most common infection risk factors are immunocompromised states, diabetes mellitus, chronic kidney disease, excessive alcohol consumption, intravenous drug use, recent or concurrent active infections, history of spinal surgeries, and advancing age.⁵ In a study involving patients with more severe spondylodiscitis involving neurologic compromise, the most common risk factors observed were advanced age, recent non-spine infection, history of spine surgery, and non-spine malignancy.⁶

Patho-anatomy/physiology

The vertebral arteries form end arteries on either side of the disc. This grants the infective organism access adjacent to the endplates. The primary site of infection usually involves the two adjacent vertebra and intervening disc.⁷ In adults, the intervertebral disc is a relatively avascular structure and provides some protection against hematogenous spread of infection to the disc. In patients under age 20, there is residual blood supply to the disc; if infection does spread to the disc, primary discitis occurs. Infection can spread locally into the disc from the adjacent vertebral osteomyelitis. The anatomy reveals that the outer two thirds of the disc is firmly adherent to the vertebral endplate, however, the central portion of the disc may be more loosely adherent and have endplate openings to allow venous drainage which can be a site of pathogen entry.

In the lumbar spine, the Batson Venous Plexus, because of its rich anastomosis with pelvic organs and its network adjacent to the intervertebral disc, is considered the most likely infectious pathway from pelvic and abdominal sources.

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

Infection often begins with microbial seeding of the vertebral endplates and intervening disc through hematogenous spread, commonly from urinary tract, skin, or respiratory sources. In the early phase, patients typically present with non-specific symptoms such as back pain. Fever is present in only about half of cases, and leukocytosis is seen in approximately one-third, making early detection challenging.⁸ As disease advances, progressive disc and vertebral destruction may result in low back pain and spinal instability.Extension of infection may result in paravertebral, epidural, intradural, or psoas muscle abscesses. If infection extends to the spinal cord or lumbosacral plexus causing compression, neurologic deficits may develop often correlating with poorer long-term outcomes.⁸ Approximately 23.5% persist with residual disabilities including chronic low back pain, paraparesis, and paraplegia.⁸ Most abscesses occur in the lumbosacral region, however, neurologic impairment is more likely with cervical and thoracic abscesses.⁴

Specific secondary or associated conditions and complications

Approximately 27.8% of patients with spondylodiscitis have concurrent infections, which is closely associated with higher mortality rate.⁹ The most common associated infections are urinary tract infections (11.3%), intra-abdominal infections (9.4%), and pneumonia (8.5%). Less common but highly morbid infections also include septic arthritis, central nervous system infections such as meningitis (0.7%), and cardiac infections such as endocarditis (0.5%).⁹ Mortality rates are significantly higher in patients with multiple concurrent infections or infections involving the cardiac, respiratory, or central nervous systems.⁹ In rare cases, the infection is walled off and becomes chronic because of formation of dead bone or involucrum. This can lead to recurrence of infection.¹⁰

Essentials of Assessment

History

Spondylodiscitis may present acutely, subacutely, or insidiously, with the latter often leading to delayed diagnosis due to mild and vague symptoms.⁶ Adults typically report dull back pain, while children may have difficulty walking, sometimes mistaken for muscle strain. Cervical infections often cause neck stiffness. About half of patients report fever, and some note prior minor trauma. Night pain is common, possibly from lower oxygen levels during sleep. Radicular symptoms may indicate epidural involvement. Chronic cases can include weight loss, poor appetite, and fatigue.

Physical examination

• There are no classical clinical signs for spine infections, but a very detailed spine and neurologic evaluation is essential.
• Tenderness and deformity of the spinous process along with muscle spasm and reduced range of motion is noted.
• Pseudoparalysis may be noted in children secondary to pain.
• Pain may be reproduced with vertical pressure on the vertebra and disc (Anvil test).
• If vertebral collapse occurs, there may be palpable deformity.
• Positive straight leg raise tests may suggest epidural involvement.
• Associated abdominal examination might be needed to assess for the presence of psoas abscess.
• Cardiac examination may be indicated to rule out infective endocarditis.

In a meta-analysis of spondylodiscitis in adult patients, the most common findings at presentation were⁴

• Back pain
• Fever
• Neurologic deficits

In comparison a systematic review in pediatric patients, the most common findings were¹¹

• Fever
• Limitation in spinal ROM (active or passive)
• Extra-skeletal manifestations (abdominal pain, constipation, and incontinence)

Functional assessment

One needs to assess if the patient can safely ambulate, whether because of pain or weakness. If there is any question of central nervous system involvement, a formal cognitive assessment would be needed.

Laboratory studies

• Complete blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and blood cultures x 3 from different sites, including aerobic and anaerobic, especially when febrile.
• The most common organism responsible for pyogenic infections is Staphylococcus aureus, followed by Escherichia coli.² Fungal infections are more likely to be seen in immunocompromised individuals and intravenous drug use.
• Testing for human immunodeficiency virus, syphilis, and tuberculosis are recommended.

Imaging

• Magnetic resonance imaging (MRI) is the test of choice with a 96% sensitivity and 94% specificity.¹¹MRI sensitivity can increase to 95.4% when performed using gadolinium contrast.¹²
• Computed tomography (CT) scan can help look for osteomyelitis, sequestrum, disc space collapse, and prevertebral and psoas abscess.
• Plain radiographs have a low specificity and sensitivity and may be negative for 2-8 weeks after initial symptoms.¹²
  • Technetium Tc 99m scan is typically positive in a few days following onset of symptoms.
• Indium-111 labeled white blood cell is a good tool for diagnosis of peridural abscess.
• Gallium citrate Ga 67 scans have been found to have a sensitivity close to 100%, with increased uptake 1 day earlier than for the Technetium Tc 99m scan. Also, gallium is helpful for chronic osteomyelitis.
  • Gallium-citrate positron-emission tomography (PET)/CT can be useful to differentiate between spinal infections and tumors.
• PET with fluorodeoxyglucose is not affected by implants and is recommended by the Infectious Diseases Society of America (IDSA) only when MRI is contraindicated.¹³
• Ultrasound has been used to diagnose discitis in infants.¹¹ Its role is primarily to diagnose and follow-up on psoas and other prevertebral abscesses.

Supplemental assessment tools

CRP has a sensitivity as high as >90%, ESR is positive in 75% of cases, whereas blood cultures are positive only in 50-60% of cases.² Because isolation of the organism will impact treatment, vertebral biopsy is required if the blood cultures are negative. CT or ultrasound-guided biopsy of the lesion is currently the most common and accurate method of securing a histopathologic diagnosis. A combined superimposed MR and CT imaging is recently being reported to help achieve higher detection rate during CT-guided biopsies.² Open biopsy may also be performed if the patient is being treated surgically.¹² Though this is crucial in subacute and chronic cases to rule out a neoplasm, the sensitivity and specificity of CT-guided biopsy or open biopsy is lower than expected, with surgical biopsy and percutaneous biopsy being positive only 58% and 57% of the time, respectively.⁴

Early predictions of outcomes

Generally, the indicators of poor long-term outcome include the following

• Presence of neurologic signs
• Longer time to diagnosis
• Hospital-acquired infection
• Level of spine involvement (cervical > thoracic > thoracolumbar > lumbosacral)

Social role and social support system

Social and home care agencies need to be involved early to prepare for after care and home antibiotic therapy.

Professional issues

Missing this diagnosis can have serious consequences for both the physician and the patient. Misdiagnosis of spinal infections is a frequent cause of malpractice suits. Worse still are the consequences for the patient as paralysis and death may result.

Rehabilitation Management and Treatments

At different disease stages

The Infectious Diseases Society of America (IDSA) guidelines recommend 6-week of parenteral or oral (high bioavailability) antibiotics for the treatment of vertebral osteomyelitis. Patients with an undrained abscess and retained hardware with infection might need treatment for as long as 3 months.¹³ Because of recent emergence of antibiotic-resistant Staphylococcus aureus, some centers are trying combination therapies. Subsequent oral antibiotic therapies after initial intravenous therapy should be determined by the results of cultures, if possible.¹⁴

In patients with tuberculosis, treatment with a combination of antituberculous agents is recommended for at least 12 months.

Surgical intervention is required for the following

• Open biopsy
• Epidural/paravertebral/psoas abscess
• Neurologic deficits
• Catastrophic infections, which are not responding to nonsurgical treatment
• Infections related to foreign bodies

Delayed surgery might be needed to stabilize the spine, this is particularly true in children where there is a significant risk for kyphoscoliosis.¹¹

Rehabilitation has critical role in managing spinal infections. Despite the significant impact of these infections on patient outcomes, rehabilitation protocols are often underdeveloped or overlooked.¹⁵

Bracing contributes to the conservative treatment of spondylodiscitis, especially in uncomplicated cases. It delivers spinal immobilization to alleviate pain and avert deformity, usually in conjunction with antibiotic therapy.¹⁶ However, a study found no significant difference in the incidence of neurological complications.¹⁷ In cases of significant spinal instability, neurological impairment, or severe pain, surgery may be an option.¹⁸

We propose a rehabilitation program based on the findings of Nas et al. (2015), which suggests that a rehabilitation protocol for spinal infections must be tailored to the individual’s neurological status and the progression of the disease.¹⁵

General Principles

• Early rehabilitation is critical.
• Multidisciplinary evaluation is essential (neurology, infectious disease, orthopedics).
• Assess neurological level, physical function, comorbidities, and surgical status.
• Monitoring progress evaluating functional status.

Acute Stage

Without Neurological Findings

• Active, active-assistive, and isometric exercises for lower limbs
• Early ambulation encouraged
• Consider bracing

With Neurological Findings

• Proper bed positioning
• Passive joint mobilizations
• Breathing exercises
• Isometric and active-assistive exercises
• In-bed functional training (e.g., head/shoulder lifts, gluteal contractions)
• Pressure sore prevention (repositioning every 2 hours)
• Urinary catheter care and constipation prevention

Subacute Stage

• Begin standing and ambulation with assistive devices
• Active and active-assistive limb exercises
• Balance and trunk stabilization exercises
• Mobilization 3–4 times/day, with rest periods
• Clean intermittent catheterization if needed

Chronic Stage

• Progressive strengthening (especially trunk and pelvic muscles)
• Functional mobility training (sit-to-stand, stairs, squats)
• Gait and balance training (with orthotics or assistive devices)
• Home exercise instruction
• Psychosocial support
• Decubitus ulcer monitoring

Home Exercise Program

• Exercises including:
  • Joint ROM
  • Strengthening of abdominal, gluteal, lumbar, and lower extremity muscles
  • Respiratory capacity and cardiovascular endurance exercises
  • Ergonomic home modifications
• Regular follow-up and re-evaluation
• Multidisciplinary coordination (infectious disease, orthopedics

Emerging/unique interventions

Emerging and unique interventions in the management of spine infections include the use of antibiotic-impregnated polymethylmethacrylate (aPMMA) strut grafts, minimally invasive endoscopic surgery, and recombinant human Bone Morphogenetic Protein-2 (rhBMP-2).

The aPMMA strut grafts incorporate antibiotics like vancomycin and tobramycin. This method provides anterior-column support while delivering antibiotics directly to the infection site. It is especially useful for severe infections with significant bone destruction, where titanium cage implants are impractical. Once resolved, aPMMA grafts can be replaced with a permanent cage and allograft.¹⁹

Minimally invasive endoscopic surgery offers a less invasive treatment for infectious spondylodiscitis, particularly in older patients or those with comorbidities. It allows for effective decompression and drainage while minimizing surgical risks. Studies show it provides quick pain relief, efficient infection management, and maintains spinal alignment without significant kyphotic changes. This technique is a viable alternative to open surgery, reducing the need for extensive surgical intervention interventions.^20-21

The use of rhBMP-2 for spinal infections aims to enhance spinal fusion and stability. Research shows that rhBMP-2 is safe for these cases, leading to high fusion rates and effective infection clearance. For instance, Sharma et al. found that rhBMP-2 use resulted in fewer complications and increased initial hospitalization payments compared to non-use. No significant differences in reoperation rates were noted at 3, 6, 12, and 24 months post-surgery, and patients receiving rhBMP-2 exhibited lower outpatient service usage overall payments.²²

These interventions signify major progress in managing spinal infections, providing effective treatment options that may reduce morbidity compared to conventional surgical methods.

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

Spine infections are diagnostically challenging due to their varying presentations. Prompt diagnosis and early treatment allow for the best chance of meaningful recovery.² Spinal infections must be suspected in all patients presenting with severe, continuous spine pain accompanied by weight loss and unexplained fever. Only through careful clinical examination, diagnostic testing, and prompt treatment can the potential damage and disability from this condition be limited. These patients exhibit more severe functional impairments at rehabilitation admission and discharge, as well as longer lengths of inpatient rehabilitation stay.⁶

Cutting Edge/Emerging and Unique Concepts and Practice

In light of Staphylococcus aureus being the most common cause of spondylodiscitis, some studies are focused on developing a serum antibody test to help guide prophylaxis and therapy in a future of personalized medicine and pathogen-specific treatments. More specifically, ratios of certain antibody levels could provide a prognostic measure of outcome.²³

Vaccines to prevent S. aureus infection has proven to be extremely challenging. However, insights gained from the failures have nevertheless helped in guiding the scientific community to continue innovating and developing diverse vaccines aimed evoking different aspects of the immune system.²⁴

In a society facing rising antibiotic resistance and the challenge of multidrug-resistant bacteria, it is crucial to address inappropriate use. A suggested solution involves a multifaceted approach that incorporates patient-specific omics data, such as, genetic vulnerability to infections (genomics), immune responses (proteomics and transcriptomics), microbiome composition, and drug metabolism kinetics. This integration would lead to the development of precise, physician-friendly algorithms along with thorough pathogen profiling, improving diagnostic accuracy and treatment appropriateness treatments.²⁵

Gaps in the Evidence-Based Knowledge

Recent rehabilitation methods for patients with spinal infections involve early mobilization, tailored physical therapy programs, and innovative technologies like robotic-assisted rehabilitation and virtual reality, which are being researched to enhance patient recovery. However, further studies are necessary to assess the proper integration of these advanced technologies in clinical practice.²⁶

References

1. Son HJ, Kim M, Kim DH, Kang CN. Incidence and treatment trends of infectious spondylodiscitis in South Korea: A nationwide population-based study. PLoS One. 2023 Jun 29;18(6):e0287846. doi: 10.1371/journal.pone.0287846. PMID: 37384614; PMCID: PMC10309630.
2. Tsantes, Andreas G et al. “Spinal Infections: An Update.” Microorganisms vol. 8,4 476. 27 Mar. 2020, doi:10.3390/microorganisms8040476
3. Tschugg, Anja et al. “Primary acquired spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery: a single-center retrospective study of 159 cases.” Neurosurgical review vol. 41,1 (2018): 141-147. doi:10.1007/s10143-017-0829-9
4. Gentile L, Benazzo F, De Rosa F, et al. A systematic review: characteristics, complications and treatment of spondylodiscitis. Eur Rev Med Pharmacol Sci. 2019;23(2 Suppl):117-128. doi: 10.26355/eurrev_201904_17481
5. Kim J,Oh SH, Kim SW, Kim TH. The epidemiology of concurrent infection in patients with pyogenic spine infection and its association with early mortality: a nationwide cohort study based on 10,695 patients. J Infect Public Health. 2023;16(6):981-988. doi:10.1016/j.jiph.2023.04.01
6. Brubaker, M L et al. “Clinical features and inpatient rehabilitation outcomes of infection-related myelopathy.” Spinal cord vol. 55,3 (2017): 264-268. doi:10.1038/sc.2016.115.
7. Sato, Kimiaki et al. “Pyogenic Spondylitis: Clinical Features, Diagnosis, and Treatment.” The Kurume medical journal vol, 65,2 (2019): 83-89. Doi:10.2739/kurumemedj.MS653001
8. Pola E, Taccari F, Autore G, et al. Multidisciplinary management of pyogenic spondylodiscitis: epidemiological and clinical features, prognostic factors and long-term outcomes in 207 patients. Eur Spine J. 2018;27(Suppl 2):229-236. doi:10.1007/s00586-018-5598-9
9. Kim J,Oh SH, Kim SW, Kim TH. The epidemiology of concurrent infection in patients with pyogenic spine infection and its association with early mortality: a nationwide cohort study based on 10,695 patients. J Infect Public Health. 2023;16(6):981-988. doi:10.1016/j.jiph.2023.04.01
10. Taylor,DavisG et al. “Presentation and Outcomes After Medical and Surgical Treatment Versus Medical Treatment Alone of Spontaneous Infectious Spondylodiscitis: A Systematic Literature Review and Meta Analysis.” Global spine journal vol 8, 4 Suppl (2018): 49S-59S. Doi:10.1177/21925682187996058
11. Ferri I, Ristori G, Lisi C, Galli L, Chiappini E. Characteristics, Management and Outcomes of Spondylodiscitis in Children: A Systematic Review. Antibiotics (Basel). 2020;10(1):30. Published 2020 Dec 31. doi:10.3390/antibiotics10010030
12. Expert Panel on Neurological Imaging, Ortiz AO, Levitt A, et al. ACR Appropriateness Criteria® Suspected Spine Infection. J Am Coll Radiol. 2021;18(11S):S488-S501. doi:10.1016/j.jacr.2021.09.001
13. Berbari EF, Kanj SS, Kowalski TJ, et al. Infectious Diseases Society of America (IDSA): clinical practice for the diagnosis and therapy of native vertebral osteomyelitis in adults. Clin Infect Dis. 2015;61:26–46
14. Baryeh K, Anazor F, Iyer S, Rajagopal T. Spondylodiscitis in adults: diagnosis and management. Br J Hosp Med (Lond). 2022;83(10):1-9. doi:10.12968/hmed.2021.0448
15. Nas K, Karakoç M, Aydın A, Öneş K. Rehabilitation in spinal infection diseases. World J Orthop. 2015;6(1):1-7. Published 2015 Jan 18. doi:10.5312/wjo.v6.i1.1
16. Waheed G, Soliman MAR, Ali AM, Aly MH. Spontaneous spondylodiscitis: review, incidence, management, and clinical outcome in 44 patients. Neurosurg Focus. 2019;46(1):E10. doi:10.3171/2018.10.FOCUS18463
17. Le Pluart A, Coiffier G, Darrieutort-Lafitte C, et al. Spine immobilization and neurological outcome in vertebral osteomyelitis SPONDIMMO, a prospective multicentric cohort. Joint Bone Spine. 2022;89(4):105333. doi:10.1016/j.jbspin.2021.105333
18. Rawall S, Hiatt LA, Rajaram SM, Theiss S. Management of Pyogenic Spondylodiscitis in Adults. J Am Acad Orthop Surg. Published online April 23, 2025. doi:10.5435/JAAOS-D-24-01088
19. Ramey WL, von Glinski A, Jack A, Blecher R, Oskouian RJ, Chapman JR. Antibiotic-impregnated polymethylmethacrylate strut graft as a treatment of spinal osteomyelitis: case series and description of novel technique. J Neurosurg Spine. 2020;33(3):415-420. Published 2020 May 8. doi:10.3171/2020.3.SPINE191313
20. Lin CY, Chang CC, Chen YJ, et al. New Strategy for Minimally Invasive Endoscopic Surgery to Treat Infectious Spondylodiscitis in the Thoracolumbar Spine. Pain Physician. 2019;22(3):281-293.
21. Lin IH, Lin CY, Chang CC, et al. Percutaneous Endoscopic Surgery Alone to Treat Severe Infectious Spondylodiscitis in the Thoracolumbar Spine: A Reparative Mechanism of Spontaneous Spinal Arthrodesis. Pain Physician. 2022;25(2):E299-E308.
22. Sharma M, Dietz N, Alhourani A, et al. Insights into complication rates, reoperation rates, and healthcare utilization associated with use of recombinant human bone morphogenetic protein-2 in patients with spine infections. Neurosurg Focus. 2019;46(1):E8. doi:10.3171/2018.10.FOCUS18448
23. Muthukrishnan, Gowrishankar et al. “Serum antibodies against Staphylococcus aureus can prognose treatment success in patients with bone infections.” Journal of orthopaedic research : official publication of the Orthopaedic Research Society vol. 39,10 (2021): 2169-2176. doi:10.1002/jor.24955
24. Clegg, Jonah et al. “Staphylococcus aureus Vaccine Research and Development: The Past, Present and Future, Including Novel Therapeutic Strategies.” Frontiers in immunology vol. 12 705360. 7 Jul. 2021, doi:10.3389/fimmu.2021.705360
25. Olivier, Michael et al. “The Need for Multi-Omics Biomarker Signatures in Precision Medicine.” International journal of molecular sciences vol. 20,19 4781. 26 Sep. 2019, doi:10.3390/ijms201947810875
26. Kuroda Y, Young M, Shoman H, Punnoose A, Norrish AR, Khanduja V. Advanced rehabilitation technology in orthopaedics-a narrative review. Int Orthop. 2021;45(8):1933-1940. doi:10.1007/s00264-020-04814-4

Original Version of the Topic 

Sarjoo M. Bhagia, MD, Jamal Balouch, MD, Kartik Swaminathan, MD. Spine Infections. 9/20/2013.

Previous Revision(s) of the Topic 

Vincent Huang, MD, Raman Sharma, MD, Conrad Fischer, MD. Spine Infections. 4/3/2017.

Casey A. Murphy, MD, FAAPMR, DAAPM, Carlos “Coco” Trigo, MD, Dean John Hendrix Dante. Spine Infections. 7/28/2022.

Author Disclosure

Pedro E. Rodriguez-Ortiz, MD, MPH
Nothing to Disclose

Ana Arrillaga-Cruz, MD
Nothing to Disclose

Jose E. Quintana-Soler, MD
Nothing to Disclose

William Micheo, MD
Nothing to Disclose