Spondylodiscitis

Original Editors - Lynn Leemans

Top Contributors - Ine Wittevrongel, Bo Hellinckx, Lucinda hampton, Admin, Kim Jackson, 127.0.0.1, WikiSysop and Claire Knott  

Introduction

Spondylodiscitis, also referred to as discitis-osteomyelitis, is characterised by infection involving the intervertebral disc (IVD) and adjacent vertebrae. The condition is difficult to treat due to the the limited blood supply to these segments, a factor that makes it also rare. Treatment consists of an extended antibiotic course, with good outcomes but misdiagnosis or a delay in treatment may result in significant morbidity/mortality.

Terminology: Discitis is discouraged as a term as isolated infection of the spinal disc rarely occurs. Normally the initial infection is the vertebral endplate with secondary involvement of the disc. The terms spondylodiscitis or vertebral osteomyelitis are preferred as they are more accurate.

Pathology

In adults, infection starts at the vertebral body endplate, extending into the IVD space and then into the adjacent vertebral body endplate.

Paediatrics present differently with infection often starting in the intervertebral disc itself as a good direct blood supply still present).

Etiology

Most cases of Spondylodiscitis arise from one of three initial events: direct inoculation, hematogenous spread, or less commonly contiguous spread. Finding the causative agent is very difficult, the most commonly identified organism is being Staphylococcus aureus.

Epidemiology

Spondylodiscitis has a bimodal age distribution

1. More common in pediatric patients than in the adult population, as consequence of the greater vascular supply of the IVD.
2. Older population ~50 years, more often men

Risk Factors

Include

• remote infection (present in ~25%)
• ascending infection, e.g. from urogenital tract instrumentation
• spinal instrumentation or trauma
• intravenous drug use (IVDU)
• immunosuppression
• long-term systemic administration of steroids
• advanced age
• diabetes mellitus
• organ transplantation
• malnutrition
• cancer

Characteristics/Clinical Presentation

The symptoms are non-specific, diffuse  and treacherous . However the usual presentation is back pain (over 90% of patients) and possibly fever (under 20% of patients). Patients are often bacteraemic , originating from eg endocarditis, intravenous drug use.Symptoms may include:

• Spinal tenderness
• Loss of lumbar lordosis and lower back movement
• Inspection on local changes and neurological status (parese, paralyse,..)
• Pain on heelstrike, impactation and percussion
• Relieving posture (avoid stressing the ventral sections of the spinal column
• Inclination and re-erection are painful
• Reduction of mobility
• Paravertebral muscle spasm 

Differential Diagnosis

Differential diagnoses include:

• Erosive osteochondrosis
• Osteoporotic and pathological fracture
• Cancer related destruction
• Ankylosing spondylarthritis
• Scheuermann's kyphosis
• Charcot joint
• Modic type I degenerative change
• Schmorl nodes
• Langerhans cell histiocytosis (LCH)
• Disc herniation
• Metastatic seeding
• Inflammatory or degenerative spinal disease 

Diagnostic Procedures

It is important to identify and treat spondylodiscitis as early as possible. The clinical presentation of spondylodiscitis are manifold. This commonly leads to a several months from initial symptoms to final diagnosis.  A number of different tests and tools help in diagnosis including:

• Medical imaging: Magnetic Resonance Imaging (MRI) : Golden standard. Detects any spread of the inflammation. ; PET and PET/CT : Due to its high specificity,  F-FDG PET/CT should be considered as a first-line imaging procedure in the diagnosis of spondylodiscitis. And others
• Biopsy: Pathogens are only successfully detected in about half of the patients. To obtain a definite diagnosis: Blood Culture
• Blood tests
  -

Outcome Measures

Include:

• Visual Analogue Scale (VAS): to evaluate therapeutic effects, for assessment of pain.
• Oswestry disability index (ODI):  to evaluate therapeutic effects, assessment of quality of life
  

Treatment

The aim of treatment is to eliminate the infection, restore and preserve structure and function of the spine, and ease the pain. Conservative management consists of antimicrobial therapy and non-pharmacological treatments, for example physiotherapy and immobilization. Immobilization is advocated when pain is significant or there is a risk of spinal instability.

Physical Therapy Management

Spinal extension

Spondylodiscitis has several clinical symptoms, a severe one is low back pain. This can be treated with exercises.

Thoracic extension

Breathing exercises

Flexibility exercises

Prognosis seems to be good with conservative treatment including NSAID’S, physiotherapy (exercises), and a corset.

Immobilization is advocated when pain is significant or there is a risk of spinal instability. Wearing the corset for a period of 6–10 weeks is confirmed by most authors.

Exercise:

• Several exercises can be done with the emphasis on extension exercises and exercises for trunk balance. This is important to maintain a good posture. Early mobilization is important.
• Limb exercises are considered to be good for the therapy. These exercises should be done daily at home.
• General fitness, like swimming, should be encouraged. This therapy can lead to a decrease in pain and the ability to accomplish activities of daily living.
• Breathing exercises. These exercises help the stability in the lower back.
• Low back pain is strongly related with tight and strained hamstrings. Patients should do flexibility exercises for the hamstrings, maintain a good position while sitting and move enough to help this. Keeping the hamstrings flexible is important for pain control as well as in prevention of spinal pain flare-ups.

In general the rehabilitation program will improve the patient’s sensory and motor skills, develop the balance and proprioception and will help the patient’s to do their daily living activities. During the total program the onset and increase of pain should be evaluated. Pain intensity increases or exercises that provoke too much pain or exhaust the patient should not be in the rehabilitation program and there has to be enough rest after the exercises. It is important that when there is a resting period, this one has to be kept minimal. Immobilization lead to weakness of the trunk and lower extremity muscles and will contribute to complications. Secondary problems because of immobilization and musculoskeletal problems should be looked after and prevented. The patient also gets a home exercise program that is based on the patient’s capacity.

Clinical Bottom Line

Spondylodiscitis can be defined as a primary infection of the intervertebral disc, with secondary infections of the vertebrae (spondylitis). It can lead to osteomyelitis of the spinal column. Pyogenic spondylodiscitis is frequently caused by the staphylococcus. Tuberculous spondylodiscitis is caused by the mycobacterium tuberculosis. The symptoms are non-specific, diffuse and treacherous. Diagnosis is difficult and often delayed or missed due to the rarity of the disease. The basic diagnostic examination to establish spondylodiscitis is MRI. Surgical and conservative treatment for postoperative lumbar spondylodiscitis is effective. Prognosis seems to be good with conservative treatment including NSAID’S, physiotherapy (exercises), and a corset.