Therapy of Spondylodiscitis

The key to successful therapy of spondylodiscitis is the consistent immobilization of the patient’s spine. So-called orthoses, which are applied similar to a corset, fix the vertebral bodies and intervertebral discs. An alternative is a plaster cast.

With both immobilizations, the patient is allowed to stand up and move as much as possible. If a complete immobilization of the spinal column with these aids does not succeed, only one option remains open: absolute bed rest. The patient is then not allowed to stand up for at least 6 weeks in order to keep his back as still as possible.

The second cornerstone of the therapy is the administration of antibiotics, which is an indispensable part of every spondylodiscitis treatment. In addition to these two measures, surgical treatment of spondylodiscitis can be considered as a complementary measure. In certain cases, which are explained in more detail below, surgery complements and completes the chosen treatment path.

An efficient and satisfactory pain therapy for the patient should not be neglected. Especially in the case of long periods of immobilization and therapy, the patient should not suffer more pain than necessary at any time. The choice of the right antibiotic is crucial for the patient’s recovery, as this is the only way to ensure a targeted therapy.

For this reason, the causative pathogen of the unspecific spondylodiscitis, as well as its sensitivity to antibiotics and possible resistances are first identified. The simplest and fastest way to detect the pathogen is by applying blood cultures. The removal of the affected tissue (biopsy) or the collection of a sample through a small operation under anesthesia are further possibilities.

In comparison to blood cultures, pathogens can be determined more precisely and reliably using these methods. However, they cost considerably more time and effort. However, if there is a need for quicker action and the patient’s condition no longer permits pathogen detection, an intravenous antibiotic is administered that has a broad spectrum of action against the most common causes of spondylodiscitis: Staphylococcus aureus and Escheria coli.

Once the pathogen has been identified, targeted antibiotic therapy is administered by infusion (‘drip’). The first choice is usually a combination therapy, i.e. the simultaneous administration of different antibiotics. Clindamycin (1800 mg per day) plus ceftriaxone (2g per day) are combined, which can alternatively be replaced by ciprofloxacin (800 g per day).

By administering the drug into the vein (intravenously), greater efficacy is achieved, as the antibiotic does not have to pass through the gastrointestinal tract and is metabolized there. In addition, some antibiotics can only be absorbed into the blood via the direct route. The course and pathogens of spondylodiscitis vary considerably, so that there are currently no uniform guidelines regarding the duration of therapy.

As a rule, antibiotics are administered intravenously and over a period of about 2-4 weeks. If the patient’s general condition and blood values (inflammation parameters) improve, oral therapy in the form of tablets or capsules can be switched to. These must be taken for up to 3 months, depending on the course of the spondylodiscitis.

For patients at risk, the duration of therapy can even be extended. Antibioses administered over a longer period of time put additional strain on the body. Numerous side effects can occur.

Often the kidney and liver suffer from the permanent administration of the drugs. It is therefore important that liver and kidney values are monitored during long-term antibiotic therapy.The surgical treatment option for spondylodiscitis consists of opening the inflamed area for the surgeon to inspect and assess the existing damage. The so-called ventral approach is often chosen for this purpose, i.e. exposing the vertebral bodies from the abdomen.

The patient lies on his back during this operation. At first, the surgeon takes samples of the inflamed area, which are then examined for the type of pathogen and the effectiveness of various antibiotics. This is followed by surgical remediation of the inflammation, i.e. generous removal of infected tissue and necrotic parts.

After this step, called debridement, the wound is thoroughly rinsed and often treated directly with an antibiotic. This step is then followed – as soon as the surgeon is certain that the inflammation situation has improved – by a so-called spondylodesis, i.e. a blockage of several vertebral bodies. This serves to stabilize and stiffen the spinal column and is usually performed using a system of metal screws and rods.

In rare cases, the patient’s healthy bone is removed from another location and moved for stabilization. Individual details of the operation and the technique used, however, differ significantly depending on the hospital and the surgeon. A physician will inform the patient about more precise details if such an operation is scheduled.

Some doctors, for example, treat everything directly in a single operation, while others rely on the so-called two-stage procedure and perform a second operation after a (smaller) first operation and an appropriate break. For the patient, this procedure has the advantage that he or she only has to undergo smaller, shorter procedures and can recover between the two operations. On the other hand, a two-stage procedure naturally still means another operation with a further anaesthetic and all the risks that an operation entails.

The decision for a one or two-stage procedure must therefore be thoroughly thought through and carefully weighed up in each case. After the operation, stabilization results in a complete elimination of mobility in the fixed segment, which on the one hand protects against subsequent vertebral body fractures and on the other hand leads to a faster, safer healing of the spondylodiscitis. Patients who have undergone surgery are allowed to return to normal mobility relatively soon, although the loss of mobility caused by the operation is well tolerated in most cases and does not represent too great a restriction.

The reasons for operating on a patient suffering from spondylodiscitis are the presence of neurological deficits (such as paralysis, paresthesia or loss of sensation), the failure of the non-operative therapy or extensive bone destruction that has already led to a significant hump. Patients whose pain cannot be alleviated even under optimal therapy should also be treated surgically. On the other hand, very old, frail patients or those who are very weak should not be operated on.

Since every operation is associated with risks, these patient groups should rather be treated without surgery. The greatest risk of surgery in spondylodiscitis is paraplegia caused by the surgeon. However, this complication is very rare, especially with the ventral approach described above.