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Radical DebridementRadical debridement without bone grafting is sufficient in cases with: Radical debridement is the key to successful surgery predominant epidural abscess absence of s

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Radical Debridement

Radical debridement without bone grafting is sufficient in cases with:

Radical debridement is the key to successful surgery

) predominant epidural abscess

) absence of significant vertebral or intradiscal involvement

) absence of gross bony destruction, deformity, and instability

Radical Debridement and Bone Grafting

Radical debridement and bone grafting are indicated in patients:

) with intraspinal abscesses

) without gross bony destruction, deformity, or instability

Primary bone grafting

is preferred

There is still debate on the timing of the bone grafting The main concern in

pri-mary bone grafting is the resolution of the graft by the infection On the other

hand, secondary bone grafting requires reoperation with theoretically increased

morbidity In the absence of conclusive data in the literature, the present author

prefers primary bone grafting unless radical debridement is not achieved In this

case, a second-look operation is imperative and, depending on the local

situa-tion, bone grafting is performed during the latter intervention.

Radical Debridement, Bone Grafting, and Instrumentation

Radical debridement and bone stable reconstruction of the spine are favored as

the surgical technique of choice based on the good results obtained with surgical

treatment of spinal tuberculosis [23, 32, 33] ( Table 5 ):

Table 5 Rationales for radical debridement and stable reconstruction of the spine

) improvement of general condition after abscess drainage

) prevention of secondary deformity

) rapid progress of infection is prevented

) in early stages, extirpation of infected focus is easy ) late recurrence is less frequent

) putative shorter hospitalization and earlier return to work

Instrumentation has increasingly been used without recurrent infection

While the use of spinal instrumentation in the presence of spinal infection has

been controversial in the literature, an increasing number of articles indicate that

instrumentation is not contraindicated in cases where radical debridement is

achieved [14] There are no sufficient data in the literature to allow a conclusive

statement on the role of instrumentation in spinal infection However, there is no

evidence to suggest that instrumentation prevents the healing of the spinal

infec-tion The additional stability instead promotes clinical resolution of the infection

and related symptoms ( Table 6 ).

Anterior Approach A single-stage anterior approach is best suited for cases with:

) predominant anterior column involvement

) effective radical debridement

) absence of gross deformity or instability

Anterior instrumentation appears not to have an adverse effect unless radical

debridement is not achieved [12] The use of anterior cages in the absence of a

structural auto- or allograft remains controversial However, early reports in the

literature indicate that this approach can be successful [21].

Posterior Approach. A single posterior approach is only indicated in cases with a

lesion with difficult anterior access, e.g., at the upper thoracic spine T2-4 In

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Table

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those cases, a costotransversectomy approach is necessary to allow for adequate

decompression of the anterior column.

Combined Approach. This is the most widely used approach [8, 12, 19, 25, 42]

consisting of short-segmental posterior pedicle screw fixation, followed by

radi-cal anterior debridement and bone grafting ( Fig 6 ) In the cervical spine, a two or

Case Study 2

An 81-year-old woman developed progressive, severe back pain Despite initial analgesics and physiotherapy, the

patient continued to get worse The patient developed a slight increased fever and felt sick After severe pain with

ambu-lation, a radiograph (a) was taken, demonstrating a collapsed L1/2 disc space with partial destruction of the lower

end-plate of L1 The MRI exhibits typical signs of a spinal infection Note the high signal intensity in a T2W MR sagittal image

(b) and a paravertebral abscess in the psoas muscles (c,d) In a first stage the spine was stabilized from T11 to L3 with a

titanium pedicle screw system In a second stage, during the same operation, the paravertebral abscess and the disc

space and adjacent vertebral bodies L1/2 were debrided The bone quality was osteoporotic A tricortical bone graft was

harvested from the iliac crest, but broke during insertion because of poor bone quality Rather than leaving a large

ante-rior gap, a titanium mesh cage was implanted, supporting the anteante-rior cortex of the severely osteoporotic vertebrae

(e,f) At 6 months follow-up the patient was ambulating without aid without limiting her daily activities, but she still had

occasional back pain There was no sign of recurrent infection during a further 1-year follow-up

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more level involvement requires additional posterior stabilization However, in cases where the general health status does not allow an additional posterior approach, external splinting is imperative until the bone graft has healed In cases

of poor bone quality, e.g., in an osteoporotic spine, longer instrumentation may become necessary In those cases, anterior buttress support is necessary to allow for stable construction In cases where a tricortical bone graft is too brittle (osteoporo-sis), a titanium mesh cage can be applied As a prerequisite, radical debridement has to be achieved prior to cage implantation and bone grafting ( Case Study 2 ).

Recapitulation

Epidemiology. In an era of very powerful

antibiot-ics, it is sometimes forgotten that spinal infections

are still a potentially life-threatening disease

To-day, spinal infections predominantly occur in the

el-derly and immunocompromised patient, but the

in-cidence of spinal tuberculosis in younger patients is

again increasing in industrialized countries.

Pathogenesis. Spinal infections in adults appear to

start from the vertebral endplates The most

fre-quent pathomechanism is a spread of

microorgan-isms via the blood vessels from urogenital,

pulmo-nary, or diabetic foot infections Spinal infections

are most frequently classified according to the

causative organism (pyogenic, parasitic, fungal

in-fections, tuberculosis) or the location (i.e., discitis,

spondylitis, epidural, and paravertebral abscess).

Clinical presentation. The key feature of spinal

in-fections is the delayed diagnosis Cardinal

symp-toms are slowly progressive, continuous pain with

pain exacerbation during rest and at night Fever

and septic states are rare It is mandatory to search

for predisposing factors such as diabetes,

intrave-nous drug abuse, immunodeficiency, diabetic

ul-cers, and previous septic conditions The physical

findings are often non-specific unless neurologic

deficits are present.

Diagnostic work-up The key to diagnosis is to

con-sider spinal infections CRP and BSR are almost

al-ways elevated while the WBC can remain normal.

The major drawback of standard radiography is the

delay in the appearance of radiographic signs The

sequence of changes demonstrable on radiographs

is blurred endplates, disc space collapse,

develop-ment of osteolysis and a paravertebral shadow,

re-active sclerosis and kyphotic deformity MRI is the

imaging modality of choice Characteristic findings

on MRI suggestive of spinal infections are

de-creased vertebral endplate signal intensity on T1W

images, loss of endplate definition, increased signal intensity on T2W images, and contrast enhance-ment of the disc and vertebral endplates The isola-tion of the causative organism is very important

and must be attempted in every case CT-guided

biopsy is the method of choice because it allows

the sample to be taken from inside the lesion The

most frequently found organisms are

Staphylococ-cus aureus (30 – 55 %), E coli, Salmonella, Enterococ-cus, Proteus mirabilis, Pseudomonas aeruginosa (in

65 % of drug abusers), Streptococcus viridans, and

epidermatitis In the absence of a life-threatening condition, treatment should not be started without vigorous attempts to isolate the causative organ-ism The likelihood of isolating the organism after the beginning of antibiotic treatment is minimal.

Non-operative treatment The general objectives

of treatment are to eradicate the infection, relieve

pain, prevent or reverse a neurologic deficit, re-store spinal stability, correct spinal deformity, and

prevent recurrence Antibiotic treatment is the

therapy of choice for uncomplicated cases Che-motherapy should not be stopped prior to normal-ization of the infectious parameters (CRP, BSR, WBC) and is usually given for 6 – 12 weeks Early ambulation is attempted and a corset can be used

optionally In cases of spinal tuberculosis, a triple

(isoniazid, rifampin, and pyrazinamide) or quadru-ple chemotherapy (plus ethambutol) is recom-mended for 2 – 3 months After this period, chemo-therapy should be continued with isoniazid and ri-fampin in the absence of resistance or side effects.

While there is still debate on the duration of

treat-ment, a total of 12 months is favored by the

majori-ty of experts.

Operative treatment Surgery is indicated in cases

of disease progression despite adequate antibiotic treatment, progressive spinal deformity and

insta-bility, and neurological compromise The key to

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successful surgery is radical debridement This has

been well demonstrated for the treatment of spinal

tuberculosis, but is applicable to pyogenic

infec-tions as well Radical debridement and bone

graf-ting are indicated in patients with intravertebral

abscess and without gross bony destruction,

defor-mity, and instability However, in many cases

addi-tional spinal stabilization is required

Instrumenta-tion is still controversial in the literature, but an

increasing number of articles have demonstrated

that implants can be used without side effects

Spi-nal instrumentation promotes rather than prevents resolution of the infection because of the added stability Posterior instrumentation with correction

of the deformity, followed by anterior radical debridement and bone grafting, is the method of choice for a spinal infection with predominant anterior column involvement of the thoracolumbar

spine Implants can be used at the site of infection

(e.g., in the cervical spine) with the prerequisite that radical debridement is thoroughly achieved.

Key Articles

Hodgson AR ( 1964) Report on the findings and results in 300 cases of Pott’s disease

treated by anterior fusion of the spine J West Pacific Orthop Assoc 1:3–7

Landmark paper favoring surgical treatment of spinal tuberculosis in a series of 300

cases

Moon MS, Woo YK, Lee KS, Ha KY, Kim SS, Sun DH ( 1995) Posterior instrumentation

and anterior interbody fusion for tuberculous kyphosis of dorsal and lumbar spines.

Spine 20:1910–6

This paper summarizes present knowledge of spinal tuberculosis and its management

Antituberculosis agents remain the mainstay of management, with chemotherapy for 12

months preferred to shorter courses Anterior surgery consisting of radical focal

debride-ment without fusion does not prevent vertebral collapse Patients who present late with

deformity are candidates for anterior debridement and stabilization with corrective

instrumentation Posterior stabilization with instrumentation has been found to help

arrest the disease and to bring about early fusion Posterior instrumented stabilization to

prevent kyphosis in early spinal tuberculosis is indicated, however, only when anterior

and posterior elements of the spine are involved, particularly in children

Carragee EJ ( 1997) Instrumentation of the infected and unstable spine: a review of 17

cases from the thoracic and lumbar spine with pyogenic infections J Spinal Disord

10:317–24

In a retrospective review of 17 consecutive cases of spinal instrumentation for pyogenic

vertebral osteomyelitis (PVO) with follow-up of 82 years, the authors demonstrated that

spinal instrumentation in selected cases of PVO allows for early mobilization and did not

seem to compromise the ability to clear infection In certain recalcitrant cases,

stabiliza-tion seemed to promote clinical resolustabiliza-tion of the infecstabiliza-tion

References

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Rheumatoid Arthritis

Dieter Grob

Core Messages

affects the cervical spine

atlantoaxial segment

instability and repetitive trauma

inter-ventions

pos-terior procedures in advanced stages of the dis-ease

planning of the extent of fusion (adjacent seg-ment decompensation)

requires fusion of the whole cervical spine

Epidemiology

Rheumatoid arthritis (RA) is a worldwide disease The original theory, that RA

only occurs in areas with cold and wet weather conditions, turned out to be

wrong; however, its incidence does seem to vary between countries [1].

Anterior atlantoaxial dis-placement is the most frequent cervical instability encountered in RA

In about 40 % of all patients with RA, the cervical spine is involved with neck

pain, and of these patients, approximately 50 % show instability of the upper

cer-vical spine complex (occiput to C2) [17] The most common instability is the

anterior translational C1/2 instability, but lateral or posterior subluxation occurs

in a minority of patients In approximately 20 %, vertical migration of the dens

may be observed, and 15 – 20 % suffer from subaxial instability with

subluxa-tions and spinal stenosis.

In spite of the success of modern medical treatment and the decreasing

inci-dence of manifest instability of the spine, surgery will remain one of the

treat-ment options in advanced stages of the disease While in the second half of the

Despite the success of modern medical treatment, surgery will remain a valid option for non-responders

last century decompressive and stabilizing surgery was the only solution for

severe alterations due to RA and thus represented some kind of last resort for

neglected RA patients, surgery in the future will be the option for

non-respond-ers to modern chemical treatment or untreated “leftovnon-respond-ers” [7].

Pathogenesis

Rheumatoid arthritis affects synovial tissue, finally forming an inflammatory

pannus, which represents an aggressive tissue with consecutive destruction of

discoligamentous structures and bony elements around the facets Due to the

anatomical configuration of the atlantoaxial segment, the manifestation of RA is

most often observed in the upper cervical spine The three-dimensional motion

in the atlantoaxial segment is controlled exclusively by the joint capsule and the

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Case Introduction

At the time of first

pre-sentation the patient was

52 years old and had

suf-fered from rheumatoid

arthritis for 4 years Due

to the aggressive course

of the disease she had

had her hips and knees

replaced due to

rheuma-toid destruction of these

joints Her neck problem

was revealed by the

flex-ion radiograph of her

cervical spine, where a

reducible subluxation of

the atlas was detected

(a) Due to persisting

pain, atlantoaxial fixation

was performed by

trans-articular screw fixation

In spite of several other

subsequent

interven-tions, the patient was

without symptoms in her

neck for several years

and a routine check-up

6 years postsurgery

showed solid fusion of

the atlantoaxial segment

in an anatomical

posi-tion Twelve years after

her neck surgery, she

started to have painful

sensations in her neck;

however, she refused to

seek medical advice,

being afraid of needing

further intervention (she had sustained a total of 23 interventions due to her rheumatoid disease up to that date!) The functional views revealed an subaxial instability (b,c) However, the pain became more intensive and she noted increas-ing clumsiness of her hands She finally presented with a stiff and painful neck A hyperreflexia of upper and lower extremities was found together with sensory disturbances in her hands A neurophysiological examination confirmed the presence of a significant cervical myelopathy The radiographs showed decompensation of the adjacent levels with significant retroposition of the vertebral body C3 producing severe spinal stenosis (d,e)

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f g

Case Introducton (Cont.)

A one-stage surgery was performed with initial anterior resection of the vertebral body of C3 With this step,

decompres-sion of the spinal canal and reduction of the deformity was achieved In the same sitting, posterior fixation was carried

out to maintain reduction and stability Laminectomy and flavectomy were performed at the same time to decompress

posteriorly Since there was no upward migration or pathology in the atlanto-occipital joint, the occiput was not

included in the fixation (f,g) After surgery, the patient recovered well and noticed an improvement in the dexterity of

her hands and a reduction of the paresthesias

ligaments – with the exception of extension, in which the dens axis serves as a

bony blocker With the destruction of the capsuloligamentous elements, a mainly

horizontally orientated instability (Fig 1 ) occurs, which is complicated by

subse-quent bony arrosion of dens and lateral masses of the atlas, leading to an

addi-tional upward migration of the atlantoaxial complex towards the foramen

mag-num.

Pannus formation

is related to instability

The inflammatory pannus seems to be one of the key factors in tissue

destruction If there is no motion, there is no pannus formation and – as a

con-sequence – no tissue destruction occurs [10] In this view, surgically induced

fusion, e.g of the atlantoaxial joint, prevents the destructive process and

there-fore prevents the transformation of a horizontal instability into a vertical

insta-bility [10] (Fig 1 ).

The subaxial cervical spine may also show instability and spinal stenosis due

to RA changes Facet joint and disc destruction as well as bony erosion cause

Disc/facet joint destruction and bony erosion cause subaxial instability

anterolisthesis and loss of lordosis and – with increasing deformity – spinal

ste-nosis with encroachment of the medulla and nerve roots Even if the involvement

of the lower cervical spine is mostly primary in the underlying disease, it may

occur secondarily as a consequence of increased lever arms due to stabilizing

procedures of the upper cervical spine ( Case Introduction ).

The lumbar spine may also be involved in RA patients; however, here the

con-sequences of long-standing steroid therapy rather than disease specific

alter-ations are predominant Therefore, degenerative spondylolisthesis and vertebral

fractures may be observed.

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