#59 Pyogenic Spondylitis Caused by Staphylococcus Aureus

General Session: Infections/Tumor

Presented by: H. Aono

Author(s):

H. Aono (1)
T. Ohwada (2)
H. Tobimatsu (1)
Y. Nagamoto (1)
S. Okuda (3)
S. Suzuki (4)
T. Oda (3)
T. Fuji (5)
M. Iwasaki (6)

(1) Osaka National Hospital, Orthopedic Surgery, Osaka, Japan
(2) Kansai Rosai Hospital, Orthopedic Surgery, Amagasaki, Japan
(3) Osaka Rosai Hospital, Orthopedic Surgery, Sakai, Japan
(4) Suita Municipal Hospital, Orthopedic Surgery, Suita, Japan
(5) Osaka Koseinenkin Hospital, Orthopedic Surgery, Osaka, Japan
(6) Osaka University Graduate School of Medicine, Orthopedic Surgery, Suita, Japan

Abstract

Background Context: Pyogenic spondylitis was a relatively rare condition before. But recently patients with pyogenic spondylitis have been increasing due to increase of compromised hosts such as diabetes. In previous reports concerning pyogenic spondylitis, Staphylococcus aureus (S.aureus) is most frequently isolated.

Purpose: The purpose of this study is to investigate clinical characteristics of pyogenic spondylitis caused by Staphylococcus aureus.

Patients and Methods: 161 patients were diagnosed with pyogenic spondylitis between 1995 and 2009 in our institutions. Among these patients, S. aureus was most frequently isolated and number of the patients was 46 (29%, 27 MSSA and 19 MRSA). This study consists of these 46 patients with S. aureus. Mean age at diagnosis was 63 years (range 16 from 82). Mean follow up period was 31 months. Surgical treatments were performed in 24 patients. Bacterial organism was isolated by fluoroscopic percutaneous biopsy of the lesion in 22 patients and intraoperative culture in 24 patients. The factors we studied were 1)compromised level 2)comorbidity 3)onset and duration to diagnosis 4)behavior of WBC and CRP 5)radiological findings 6)clinical results of treatment.

Results:

1) Compromised level was cervical in 6 patients, thoracic in 12 patients and lumbar in 28 patients.

2) 25 patients had comorbidity which revealed diabetes mellitus: 10 patients, auto immune disease: 5 patients, chronic renal failure: 5 patients and malignancy: 4 patients.

3) Onset was acute in 24 patients, sub-acute in 17 patients and insidious in 5 patients. Duration to diagnosis varied from 3 days to 6 months. There was no difference in onset between MSSA and MRSA.

4) WBC was more than 10000/µl in 19 patients and mean CRP at diagnosis was 92 mg/l. Peak of CRP during the course of treatment was varied from 7 to 249 mg/l.

5) Concerning the radiological findings at diagnosis, some cases had severe bony destruction which needs reconstruction surgery. Meanwhile, there were cases that had little bony destruction despite long term morbidity without diagnosis.

6) Two patients died before infection had cured. Except these patients, infection was suppressed and 40 patients reached negative CRP value.

Duration to reach negative CRP value was varied from two weeks to 32 weeks (mean8.0±8.0 weeks) and no difference was found between MSSA (7.4±7.6 weeks) and MRSA (9.0±8.7 weeks).

Conclusions: In previous reports concerning pyogenic spondylitis, S. aureus is most frequently isolated. But there is no report which focused on clinical characteristics of one bacterium. We might have impression that pyogenic spondylitis caused by hypovirulent bacteria easily become insidious. But clinical character is different even with the same bacteria. Therefore, it is difficult to detect bacteria by clinical findings only. We conclude that onset, laboratory data and radiological findings differ from each case, though it is caused by same bacteria. We also conclude that comparing clinical features between MSSA and MRSA, no difference was found.