Diskitis:
A Prospective
Diagnostic
Analysis
Gerald W. Fischer, M.D., Gregory A. Popich, M.D., Daniel E. Sullivan, D.O.,
Gerald Mayfield, M.D., Bruce A. Mazat, M.D., and Peter H. Patterson, M.D.
From the Departments ofPediatrics and Radiology and the Orthopedic Service, Trip/er Army Medical Center, Honolulu
ABSTRACT. In a three-year prospective analysis of nine
patients with suspected diskitis, seven were confirmed as having diskitis, one had sacroiliac septic arthritis, and one had Guillain-Barr#{233} syndrome. The mean age of the patients was 3.3 years, and four of the seven were girls. Routine lumbar spine roentgenograms were not diagnostic for three to eight weeks. Nuctear imaging procedures, however, produced abnormal scans in all nine studies. Technetium Tc 99m diphosphonate scans were abnormal within seven days of symptoms, gallium citrate Ga 67 scans within 14 days. Scans were abnormal on seven occasions when standard roentgenograms were not diagnostic. The diskitis patients had tow-grade fever (seven), irritability (six), and leg or hip complaints (six). Early, rapid diagnosis is critical with this disease because some cases have been misdiagnosed as meningitis, appendicitis, or septic arthritis. Four of the seven patients had evidence of viral disease, white /3-hemolytic streptococci and anaerobic diphtheroids were isolated from two disk space aspirates. Spica casts were used in six patients to encourage immobilization, antibiotics in two, and one
patient received no specific therapy. All patients recovered regardless of therapy.
The present study is the first known prospective study of diskitis. The data thus far collected suggest that this disease is more common than previously recognized and that with the use of radiopharmaceuticals, cases previously missed may now be accurately diagnosed as diskitis. Pediatricians are urged to consider this diagnosis in any child with fever, irritability, and vague abdominal, leg, or back complaints whose origin is not identified. Pediatrics 62:543-548, 1978,
diskitis, radionuclide scans, radiopharmaceuticats.
Diskitis is an inflammatory process of the
intervertebral disk space.’ Although the exact
etiology is unknown, it is generally considered to
be a low-grade viral or bacterial infection.25
Since few pediatricians are familiar with this
disease, it generally is not considered as a cause of
fever and irritability in young children.
Further-more, the diagnosis of diskitis is difficult clinically
because it often mimics other serious diseases
such as septic arthritis, appendicitis, meningitis,
and osteomyelitis.275 Misdiagnosis has led to
inappropriate diagnostic procedures, including
hip exploration and laparotomy. The typical child
is 2 to 3 years old and has fever (38 to 39#{176}C)with
irritability for several days. A limp may be the
only suggestive finding initially, or the child may
cry or refuse to walk or sit up. Generally, the
child becomes calm and asymptomatic when
lying flat.
After we diagnosed one case of diskitis and
reviewed the literature, it became apparent that
if an etiology was going to be found and effective
therapy established, a rapid and accurate
diagnos-tic procedure was necessary. Laboratory tests are
nonspecific and generally not helpful.
Roentgeno-grams of the spine are the standard method
available to diagnose diskitis, but disk space
narrowing may not occur for several weeks after
the onset of symptoms.’5 Numerous diagnostic
and therapeutic considerations might therefore
continue, with extensive and often invasive
stud-ies being performed.
With these considerations in mind, we began a
prospective study to analyze patients with
suspected diskitis. Gallium citrate Ga 67 and
technetium Tc 99m diphosphonate scanning were
found to rapidly and accurately diagnose diskitis
even in the early phase of disease before disk
space narrowing occurs. Resolution of acute
symptoms occurred with bed rest or
immobiliza-tion alone. This process may be more common
than previously recognized.
Received November 1, 1977; revision accepted for pubtica-tion February 24, 1978.
TABLE I
CLINICAL PRESENTATION
Case/Age/ Sex
Month of Onset
Temperature (#{176}C)
ESR (mm! hr)
Presentation Disk Space
inuolce(1
1/10 yr/F May 38.2 45 Hip pain, limp L3-4 2/2 yr/F Oct. 38.2 51 Hip and flank pain
(episodic)
L2-3
3/3 yr/M April 37.9 45 Upper respiratory in-fection, tow back pain
L3-4, L4-5
4/3 yr/F May 38.9 30 Back and leg pain, re-fusal to walk,
van-celia
L4-5
5/22-24 mo/F July 37.9 49 Diarrhea, refusal to
stand or walk
L5-S1
6/3 yr/F Oct. 37.9 48 Refusal to walk, bitat-erat hip pain
L4-5
7/14-24 Iflo/M Sept. 38.6 54 Refusal to walk L2-3 8/4 yr/M Sept. 38.0 26 Refusal to walk,
ques-tionable back pain
None (Guillain-Banr#{233}
syn-dronie)
9/9-12 nio/F Aug. 42.0 41 Limp, back pain None (sacroiliac septic arthritis)
MATERIALS
AND METHODS
From June 1973 to December 1976, nine
chil-dren were evaluated with clinical findings
sugges-tive of diskitis. Two types of
radiopharmaceuti-cals were used to localize the areas of
inflamma-tion. Gallium citrate Ga 67, 75 tCi/kg, was
injected intravenously. Scans were then obtained
at 2, 24, and 72 hours after injection. Technetium
Tc 99m diphosphonate, 300
tCi/kg,
was injected1V and scanning performed three or four hours
after injection.
To be considered as diskitis, the following
criteria were required: negative tuberculin skin
tests, no evidence of other disease that could
explain the clinical disease, and unequivocal disk
space narrowing on serial spine roentgenograms.
Vertebral body erosions were also present in most
cases.
RESULTS
Of the nine patients with clinical findings
suggesting diskitis, seven were confirmed as
having the disease (Table I). The children’s ages
ranged from 14 months to 10 years (except for the
one 10-year-old, all other children were 3 years of
age or less). All children had temperature higher
than 37.8#{176}C. The fever course was usually
episodic, and maximum temperature elevations
generally did not exceed 39#{176}C. Hip or leg
complaints were present initially in six of the
seven cases. Back symptoms were noted in only
two cases. The two nondiskitis cases were
even-tually diagnosed as sacroiliac joint septic arthritis
and Guillain-Banr#{233} syndrome.
Four of the seven patients with diskitis had
prodromes suggestive of viral infections. Viral
upper respiratory infections were noted in two
patients, enteritis and diarrhea in another, and
vancella in the fourth. Blood and urine cultures
were all negative for bacterial pathogens. Two
patients had cultures of disk material. Anaerobic
diphtheroids were cultured from one patient and
/3-hemolytic streptococci (not groups A, B, or D)
were isolated from the other.
Serial lumbar spine roentgenognams were not
diagnostic for three to eight weeks.
Radiopharma-ceuticals, however, produced abnormal scans in
all nine studies. Both gallium citrate Ga 67 and
technetium Tc 99m diphosphonate were
effec-live, with the technetium scan abnormal within
seven days of symptoms and the gallium scan
within 14 days. Scans were abnormal on five
occasions when standard roentgenognams were
not diagnostic (Table II). Technetium scans were
interpretable within three to four hours after
injection; however, gallium scans were generally
not diagnostic until 24 to 72 hours after injection.
No adverse effects were noted from either of the
administered radiophanmaceuticals.
The two initial patients studied were given a
TABLE II
DIAGNOSTIC TECHNIQUES
Case
3 4 5 6 7
Gallium Abnormal Abnormal Not Not Abnormal
citrate Ga 67 (April 28) (June 9) done done (Oct. 4) scan
Technetium Abnormal Abnormal Abnormal Abnormal Abnormal
Tc 99m (May 6) (June 13) (July 16) (Sept. 28)
diphosphonate scan
Roentgen- Normal Abnormal Normal Abnormal Normal
ogram (May 8) (June 12) (July 15) (Sept. 30)
14 days). Thereafter, bed rest or spica casts were
the only therapeutic measures. Spica casts were
utilized if the patient was having discomfort
while at bed rest, as an added means of
immobili-zation. Spica casts were placed on six children,
and symptoms disappeared in 48 to 72 hours. One
child who received only bed rest also recovered
completely. Clinical recovery was complete by
the second to fourth month after the onset of
symptoms, and the ESR was normal by four to
five months. Although all symptoms resolved, disk
space narrowing and vertebral body erosions
persisted throughout the study period.
CASE REPORTS
Case 1
A 3-year-old Caucasian-Hawaiian boy had the onset of an upper respiratory infection accompanied by aching tow back pain and inability to flex his lower back. Approximately one week prior to admission, white turning, he experienced severe back pain that made him cry. His mother denied any history of fever, chills, weight loss, sweats, or back injury.
On physical examination, the patient was an extremely active, alert boy. Vital signs were normal, with a tempera-ture of 38#{176}C.Gait examination gave normal findings, but the lumbar spine was held stiff with no forward flexion. There was RO pain on palpation or percussion of the lumbar spine, but there was some diffuse tenderness in a vague pattern over the area between L-4 and the sacrum. He was able to stand or jump on each leg independently and to squat and rise without evident pain; however, he kept his lumbar spine
straight and rigid during these maneuvers. Motor,
neuro-logic, and sensory examinations of the lower limbs gave normal findings. There was a normal range of motion of the hips and knees bilaterally.
White blood cell count was 5,400/cu mm; ESR, 45 mm/hr. C-reactive protein and antistreptotysin titer were
normal.
The patient was placed at bed rest. On the third hospital day, he became febrile with elevation of temperature to 39#{176}Cthat continued over the next several days. Serial blood cultures were normal. A conventional lumbar spine series obtained on admission was considered normal. A gallium
scan obtained two weeks after the onset of symptoms (at a time when the lumbar spine roentgenograms were consid-ered normal) was abnormal, with increased deposition of radioactivity in the region of L-3 (Fig. 1). The technetium bone scan obtained one week later was abnormal, showing increased activity at the L3-4 and L4-5 levels (Fig. 2). The patient gradually became afebrile and was asymptomatic on the ward with the exception of continued low back pain. The patient was placed in a spica cast four weeks after the onset of symptoms and became asymptomatic within 48 hours.
Case 2
The second child was a 22-month-old white girl with a history of waking up at night screaming. She also had diarrhea, and lethargy for three days, with refusal to put weight on the lower extremities. The mother noted that she had been irritable when her diapers were being changed.
During the physical examination, she was noted to be irritable and the back appeared to be held rigidly. There was no tenderness on palpation of the spinous processes or paravertebral muscutature. She resisted flexion and extension of her spine.
Roentgenograms of the hips, lower extremities, and lumbosacral spine on admission were within normal limits except for a suggestion of scoliosis centered at L3-4. Seven days after the onset of symptoms, a bone scan with
techne-titini showed increased activity at the L5-S1 level. Pain continued for ten more days, and she was placed in a body spica cast and became asymptomatic within 48 hours. Roentgenograms subsequently confirmed disk space narrow-ing at the L5-S1 interspace.
DISCUSSION
Although diskitis is a definite disease entity and
has been recognized since 1925, few
pediatri-cians ever make this diagnosis. Only two reports
of diskitis have appeared in the pediatric
litera-tune in the last decade,7 and only one was from a
pediatric department. Both were retrospective
reviews. The fact that we observed seven cases in
less than three years suggests that this entity is
more common than previously suspected. A high
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FIG. 2. Case 1. Technetium Tc 99m diphosphonate scan on May 6, one week after gallium scan, showed increased activity at L3-4 and L4-5. Subsequent roentgenograms
demonstrated disk space collapse at both levels.
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FIG. 1. Case 1. Gallium citrate Ga 67 scan on April 28, two weeks after onset of symptoms, demonstrated increased activity in L-3 region. Lumbar spine roentgenograms on the
following day were normal.
effective diagnostic techniques may have
uncov-ered cases that otherwise might have been
misdiagnosed. Clinical diagnosis is often difficult
and at times impossible unless the physician is
extremely persistent in examining the back.
Enythnocyte sedimentation rates are consistently
elevated in diskitis as in many other diseases and
thus do not help in localizing the site of disease.
All but one of our children were 3 years of age or
younger, and back complaints were uncommon.
Most children complained of pain when sitting,
standing, or trying to walk, and irritability was
often pronounced. Therefore, the hips and legs
often became the area of focus for admitting
physicians. Straight leg raising and hip
examina-lion often produced increased irritability,
rein-forcing the physician’s concern about the legs.
With fever, refusal to walk, irritability, and an
elevated ESR, one can see why septic arthritis or
osteomyelitis might be considered as the initial
diagnosis. Some patients have abdominal
com-plaints or meningeal signs, and appendicitis or
meningitis might be suspected. Rapid, accurate
diagnosis is essential.
Early in the course of diskitis, there are few
diagnostic roentgenographic changes. Loss of
normal lordosis or vertebral body end plate
irreg-ulanties may be seen early, but we found that
prospectively they were difficult to rely on unless
the disk space was narrowed. Tomognams may be
helpful in evaluating specific 10 Disk space
narrowing may not occur for two to four weeks;
in two of our patients, definite narrowing was not
present for six and eight weeks, respectively.
Unless roentgenognams of the spine are repeated
every one to two weeks, these changes may not be
recognized.
In a previous report on strontium 87rn
scan-ning, three cases with diskitis were diagnosed, but
details of the cases were not ‘ The earliest
scans we have obtained were within seven days
after the onset of symptoms and they were
abnormal. Although both gallium citrate Ga 67
and technetium Tc 99m diphosphonate were
effective in localizing the lesion, we prefer
tech-netium because there is less exposure to radiation
and the scans can be interpreted within three to
four hours after injection instead of the 24 to 72
however, the gallium scan is more easily
inter-pretable, and if doubt exists after a technetium
study, the gallium scan may be of value.
The etiology and pathophysiology of childhood
diskitis remain obscure. One author has proposed
that the majority of cases are noninfectious and
are due to a partial dislocation of the epiphysis of
the vertebral body.’2 Others have combined
diski-tis with vertebral osteomyelitis.’#{176} Since in adults
the disk is avascular, vertebral osteomyelitis
extending to include the disk space is the more
likely progression of this disease in older
individ-uals. In young children, however, the disk is
supplied by blood vessels from the adjacent
verte-bral bodies that regress during childhood and are
atrophic after the third decade of life.’3
Hema-togenous spread of infection directly to the disk is
therefore possible and would occur most
frequently in the younger ages. Changes seen in
the vertebral body end plates may reflect pressure
and herniation of the disk itself and do not
necessarily indicate that the inflammatory
pro-cess started in the vertebrae.
It appears that diskitis is a common end process
probably produced by a number of etiologic
agents generally of low virulence and cleared
eventually by the body’s immunologic defense
mechanisms. During the inflammatory process,
the intervertebral disk and the contiguous
verte-bral body surfaces are destroyed and disk space
narrowing and bony erosion are observed.
Trau-ma to the back has been implicated as an
initiat-ing factor in this disease,2414 and at least one of
our children had injured the back shortly before
symptoms occurred, but the role of trauma is not
clear. Disk space cultures have demonstrated a
bacterial pathogen in several cases (mostly
Staphylococcus aureus),26 but the majority of
cultures have been negative.8’2 Three of our
patients had evidence of viral infections early in
the disease course, and one patient developed
clinical vanicella. These data suggest that viruses
may play a role in this process. Bacteria were
cultured from the disks of two of our patients. If a
clear and accurate infection etiology is to be
found in diskitis, direct cultures from the disk
space must be obtained early in the course of
disease. Since previous disk space culturing had to
await collapse of the disk space to localize the
area of infection (which often took several weeks),
it is not surprising that culture-negative,
nonspe-cific inflammatory reaction was often the only
diagnosis. Since the area of disease can now be
rapidly localized, an aspiration technique for
culture and cytology was examined. Under
fluor-oscopy, a No. 18 spinal needle is passed through
the paraspinal muscles just inferior to the lateral
process of the vertebra and inserted into the
involved disk space. Negative pressure is then
applied to the syringe and the needle removed. A
small amount of material is then retained in the
needle for culture and cytology. This procedure is
superior to the Craig biopsy technique because it
is less destructive to the disk. Since the aorta and
inferior vena cava lie just anterior to the
interver-tebral disk, a small needle also seems less
danger-ous. This culture technique was used in an adult
with diskitis following spinal anesthesia and in a
3-year-old child with classical diskitis. In both
cases, the cultures were positive.
Previous reports have suggested that antibiotics
are
of no value in childhood diskitis.2” Nodiffer-ence was seen in the course of disease between
our patients who received antibiotics and those
who did not. If, however, bacteria are recovered
from blood or disk aspirate culture, appropriate
antibiotic therapy is indicated. Spica casting
probably does not alter the disease process, but
within 48 to 72 hours most patients are symptom
free and some begin ambulating without pain. No
controlled studies have been done, and the
long-term prognosis for this disease is not known.
In summary, seven patients with diskitis were
diagnosed and treated over a three-year period.
Gallium and technetium scans were rapid and
effective methods of diagnosis. Evidence suggests
that this disease is more common than previously
recognized and that with these better diagnostic
techniques, cases previously missed may now be
accurately diagnosed as diskitis. Early diagnosis
will also allow accurate etiologic and therapeutic
investigations and will hopefully prevent
laparot-omies, joint explorations, and other invasive
procedures. Pediatricians are urged to consider
the possibility of diskitis in any child with fever,
irritability, and vague abdominal, leg, or back
complaints whose origin cannot be ascertained.
REFERENCES
1. Menelaus MB: An inflammation affecting the interver-tebral discs in children. I Bone loint Surg 46:16,
1964.
2. Spiegel PG, Kengla KW, Isaacson AS, et al: Interverte-brat disc space inflammation in children. I Bone Joint Surg 54:284, 1972.
3. Lascari AD, Graham MH, MacQueen JC: Intervertebral disc infection in children. I Pediatr 70:751,
1967.
4. Doyle JR: Narrowing of the intervertebral disc space in chitdren. I Bone Joint Surg 42:1191, 1960.
5. Mathews 55, Wiltse LL, Karbelnig MJ: A destructive lesion involving the intervertebral disc in children.
6. Milone FP, Anthony JB, Ivins JC: Infections of the intervertebral disc in chitdren. JAMA 181:1029, 1962.
7. Rocco HD, Eyring EJ: Intervertebral disk infections in children. Am I Dis Child 123:448, 1972.
8. Moes CAF: Spondyiarthritis in childhood. Am I Roent-genol Radium Ther Nuc/ Med 91:578, 1964.
9. Mayer L: Unusual case of infection of spine. I Bone Joint Surg 7:957, 1925.
10. Bonfigiio M, Lange TA, Kim YM: Pyogenic vertebral osteomyetitis: Disc space infections. C/in Orthop
96:234, 1973.
11. Staheli LT, NeIp WB, Marty R: Strontium 87m scan-ning. JAMA 221:1159, 1972.
12. Alexander CJ: The aetiology of juvenile spondylarthritis (discitis). Clin Radio! 21:178, 1970.
13. Coventry MG, Ghormley RK, Kernohan JW: Interverte-bral disc: Its microscopic anatomy and pathology: Part I. Anatomy, development and physiology.
JBone Joint Surg 27:105, 1945.
14. Saenger EL: Spondytarthritis in children. Am I Roent-geno/ Radium Ther Nuci Med 64:20, 1950.
CONCERNING
THE ORIGINS
OF CULTURES
No doubt my story [concerning the origins of cultures] would be more
inspirational if I could set aside [a] cost/benefit approach to cannibalism and
return to the old theory of moral progress. Most of us would prefer to believe
that the Aztecs remained cannibals simply because their morals were mined in
primitive impulses while the Old World states tabooed human flesh because
their morals had risen in the great onwards-and-upwards movement of
civilization. But I’m afraid this preference arises from provincial if not
hypocritical misconceptions. Neither the prohibition of cannibalism nor the
decline of human sacrifice in the Old World had the slightest effect on the rate
at which the Old World states and empires killed each other’s citizens. As
everyone knows, the scale of warfare has increased steadily from prehistoric
times to the present, and record numbers of casualties due to armed conflict
have been produced precisely by those states in which Christianity has been
the major religion. Heaps of corpses left to rot on the battlefield are no less
dead than corpses dismembered for a feast. Today, hovering on the brink of a
third world war, we are scarcely in a position to look down on the Aztecs. In
our nuclear age the world survives only because each side is convinced that the
moral standards of the other are low enough to sanction the annihilation of
hundreds of millions of people in retaliation for a first strike. Thanks to
radioactivity the survivors will not even be able to bury the dead, let alone eat
them.
From Harris M: Cannibals and Kings. New York, Random House, 1977.
