73. Knee joint prosthetic osteomyelitis due to Brucella melitensis fifteen years after prosthetic placement
Session: Posters in the Park: Posters in the Park
Wednesday, October 3, 2018: 5:30 PM
Room: N Hall D Opening Reception and Posters in the Park Area
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  • Final Diagnosis:

    Periprosthetic osteomyelitis and L4 - L5 spondylitis due to Brucella melitensis

    Brief history of the Present Illness:

    A 48 year old male from Central Mexico presented with two month history of left knee erythema, swelling and progressive pain which limited standing up or walking attributed to prosthetic loosening. He was submitted to surgery where purulent material was obtained. The prothesis was withdrawn and was replaced with a medicated cemented spacer.

    Past Medical History including allergies:

    Left distal femur pathological fracture in 2002, secondary to giant cell tumor. He was managed with surgical treatment with a non conventional Fabroni prosthetic device replacing the left knee. He presented with tumor relapse in 2004 requiring new surgical intervention without prosthetic exchange.

    Prosthetic loosening in 2010; no surgical treatment required.

    Key Medications:


    Epidemiological history:

    Drank and ate non pasteurized goat milk and cheese. He took care of goats which had caseous lymphadenitis.

    Physical Examination:

    The patient appeared well, without respiratory distress, no weight loss or paleness. The blood pressure was 130/80 mm Hg, pulse 82 beats per minute, temperature 98.6ºF (37ºC), and respirations 19 breaths per minute. Left knee appeared swollen and warm, spontaneously painful, non-fluctuating, the surgical scar had no abnormalities and the knee movements were limited. The rest of the physical examination was otherwise normal.


    White blood count 12.7 x 10^3cels/mm3 (4.8 - 10.8), total neutrophils 9.9 x 10^3cels/mm3 (1.4 - 6.5), total lymphocytes 1.5 x 10^3cels/mm3 (1.4 - 3.4), total monocytes 1.2 x 10^3cels/mm3 (0.1 - 0.6), Hemoglobin 12.3 g/dL (12 - 16), Hematocrit 36.3% (37 - 47), platelets 271 x 10^3cels/mm3 (130 - 400). C-reactive protein 1.68 mg/dL (0.02 - 0.9 ). Other laboratory results were either negative or within normal range.

    Clinical Course Prior to Diagnosis:

    Since 2010 he had prosthetic loosening, documented with X Ray study, he received no treatment. He had been complaining of increasing pain and movement limitation of the left leg for the last year.

    Differential Diagnosis:

    1. Haemophilus influenzae prosthetic joint infection

    2. Bordetella bronchiseptica prosthetic joint infection

    3. Oligella ureolytica prosthetic joint infection

    4. Brucella melitensis prosthetic joint infection

    5. Francisella tularensis species prosthetic joint infection

    Diagnostic Procedure(s) and Result(s):

    • Aerobic secretion culture at three days incubation positive for gram variable non-motile cocobacillar structures (Figure 1) which grew on blood agar but didn’t grow on MacConkey agar. Biochemestry: positive oxidase reaction, positive urease reaction.
    • Vitek and Maldi-TOF: unable to identify
    • Brucella serology (ELISA): positive 1:2
    • Polymerase chain reaction 16S rRNA: Brucella melitensis
    • SPECT scan with UBI - Technetium 99 showed enhanced and increased radioisotope uptake at the distal third part of the left femur (Figure 2), patella and proximal third of the tibial bone, as well as at lumbar vertebrae (L4 - L5) and left sacroiliac joint highly suggestive of osteomyelitis. (Figures 3 and 4)


    Amikacyn 1 gram OD for 7 days

    Doxycyclin 100 miligrams BID for 8 weeks

    Rifampin 300 mg TID for 8 weeks

    Followup SPECT scan with UBI - Technetium 99 was performed after eight weeks of antibiotic treatment. Persistent enhanced and increased radioisotope uptake at the distal third part of the left femur and proximal third of the tibial bone. Lumbar vertebrae and left sacroiliac joint without enhacement. (Figure 5)

    Prosthesis was withdrawn and the patient completed 12 weeks of Rifampin 300 miligrams TID and Doxycyclin 100 miligrams BID.

    Brief Discussion of Differential/Major Teaching points of case:

    Brucellosis is the most common zoonosis worldwide. Approximately 500,000 cases are reported annually.1 The major endemic areas are Mediterranean basin, Persian Gulf, Indian subcontinent, Mexico and Central and South America.2 Few prosthetic joint infections have been published worldwide.3 Yet, in endemic zones, patients with chronic prosthetic joint infections should be taken into account as a diagnostic consideration regardless of the prothesis’ age. Searching for epidemiological and risk factors on every patient, like laboral or recreative exposure to potentially infected cattle or consumption of non pasteurized dairy products, as well as traveling to endemic areas is crucial.3 This diagnosis should be considered in those patients who have clinical manifestations of chronic prosthetic joint infection whose microbiological diagnosis has been limited by conventional culture methods. MALDI-TOF has shown to be a useful diagnostic tool, however database is restricted and has not incorporated Brucella due to their potential bioterrorism use.4 Polymerase chain reaction 16s rRNA has proved to be an effective diagnostic method, with an 88% sensitivity and 100% specificity.5 Other tools that should be taken into consideration are serology or tube / plate agglutination.6 Taking into account that only 30 percent present as a single site of infection it is imperative to practice a whole body molecular image studies like gammagram or SPECT with UBI-Technetium 99, to investigate other sites of involvement even in the absence of symptoms. Spondylitis is a major complication and it requires prolonged antibiotic treatment. Good response rates have been documented with triple therapy consisting in Gentamicin 5 mg/kg QD for one week plus Doxycyclin 100 mg BID and Rifampin 300 mg TID for eight weeks, with withdrawal of the prosthetic device.9

    Final Diagnosis:

    Periprosthetic osteomyelitis and spondilitis due to Brucella melitensis


    1. 1. Bosilkovski M, et al. Acta Clin Croat. 2009 PMID 19623871
    2. 2. Pappas G, et al. Lancet Infect Dis. 2006;6(2):91. PMID 16439329
    3. 3. Domenica Flury, et al. J Bone Joint Infect 2017;2(3): 136-142 PMID 28540150
    4. 4. Lerreira, Laura et al. PLoS ONE 5(12): e 14235 PMID 21151913
    5. 5. Surucuoglu S, et al. Pol J Microbiol. 2009 PMID 19469281
    6. 6. Mantur BG, et al. Indian J Med Microbiol 2007. PMID17901634
    7. 7. Kamaleshwaran KK, et al. Indian J Nucl Med. 2015 Jul-Sep PMID 26170572
    8. 8. Love C, et al. Clin Radiol. 2016 PMID 26897336
    9. 9. Buzgan T, et al. Int J Infect Dis. 2010 PMID 19910232


    Figure #, location of image, type of image, legend

    1. Figure 1. Slide 5. Secretion culture gram stain, gram variable cocobacilliar structures

    2. Figure 2. Slide 6. Left leg SPECT scan UBI - (99m)TC. Enhancement due to radioisotope increased uptake of the distal third part of the left femur, patella and proximal third of the tibial bone (most representative image of the case)

    3. Figures 3 and 4. Slide 6. Lumbar and sacroiliac SPECT scan UBI - (99m)TC Radiosiotope increased uptake at lumbar vertebrae (L4 - L5) and left sacroiliac joint highly suggestive of osteomyelitis

    4. Figures 5 and 6. Slide 7. Follow-up lumbar and sacroiliac SPECT scan UBI - (99m)TC performed 8 weeks after starting treatment No radiosiotope increased uptake at lumbar vertebrae and left sacroiliac joint

    Andrea Cárdenas-Ortega, MD, Infectious Diseases, Instituto Nacional de Cancerología, Mexico City, Mexico and Patricia Volkow, MD, Infectious Diseases Department, Instituto Nacional de Cancerologia, Mexico City, Mexico


    A. Cárdenas-Ortega, None

    P. Volkow, None

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