Delay in Diagnosis of Vertebral Osteomyelitis Affects the Utility of Cultures.
BACKGROUND
Obtaining blood or tissue cultures prior to administration of antibiotics has been the standard of care in the treatment of osteomyelitis of the spine. A delay in diagnosis of vertebral osteomyelitis is the primary culprit for the inaccuracy of blood cultures and biopsies. The purpose of this study was to evaluate the outcomes of spinal osteomyelitis in patients where the infecting organism was identified through cultures in contrast to cases where the cultures continued to be negative.


METHODS
We retrospectively reviewed the database of spinal osteomyelitis cases presented at a high-volume institution from 2001-2011. This resulted in 91 patients (51 men and 40 women) who had a mean age of 59 years with a mean follow-up of four years. Delay in diagnosis was defined as greater than 2.5 months from first ER visit for non-specific back pain to diagnosis of osteomyelitis without antibiotic treatment in the interim. Nineteen patients had a delay in diagnosis (DD) and 72 were diagnosed early (ED). Outcomes evaluated include clearance of infection, clinical outcomes measured by Oswestry disability index scores (ODIs), and the efficacy of blood cultures and biopsies.


RESULTS
The ED group had a higher odds ratio of osteomyelitis clearance compared to the delay in diagnosis group and this trended toward significance [p=0.08]. The mean improvements in ODIs were significantly greater in the ED group compared to the DD group. Positive blood cultures were more positive when drawn within one month compared to after one month [p=.001]. Percutaneous biopsy cultures were more positive when drawn within 2.5 months compared to after 2.5 months [p=.025]. Open biopsy cultures were more positive when drawn within 4.5 months compared to after that [p<0.001].


CONCLUSIONS
We found that delayed diagnosis may negatively affect the treatment outcome as evidenced by the greater improvements in ODI scores among those diagnosed early. Although we were unable to show a difference in clearance between early and delayed diagnosis, it is quite possible that larger cohorts may have shown this given the trend toward significance.


CONCLUSIONS
Hence, an early diagnosis has improved vertebral osteomyelitis clearance and clinical outcomes, and blood cultures and biopsies may have a low yield if delayed.
Seton Hall University, St Joseph's Regional Medical Center, Paterson, NJ.
Kimona
K
Issa
Department of Orthopaedics, University of California, Los Angeles, Los Angeles, California.
Sina
S
Pourtaheri
Department of Medicine, Temple University Hospital, Philadelphia, Pennsylvania.
Anita
A
Vijapura
Department of Orthopaedics, Wayne State University, Detroit, Michigan.
Tyler
T
Stewart
Seton Hall University, St Joseph's Regional Medical Center, Paterson, NJ.
Kumar
K
Sinha
Seton Hall University, St Joseph's Regional Medical Center, Paterson, NJ.
Ki
K
Hwang
Seton Hall University, St Joseph's Regional Medical Center, Paterson, NJ.
Arash
A
Emami
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001706:Biopsy; D057210:Delayed Diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000175:diagnosis* / Q000188:drug therapy; D013131:Spine; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents