Table 1.
Characteristics of 124 Patients With Osteoarticular Infections Due to Methicillin-Susceptible Staphylococcus aureus
| Characteristic | Total (N = 124) | Ceftriaxone (n = 74) | Oxacillin (n = 50) | P value |
| Age, years, mean (± SD) | 51.6 (±15.9) | 51.1 (±17.7) | 52.4 (±12.7) | .6 |
| Sex, male | 74 (60%) | 44 (60%) | 30 (60%) | >.99 |
| Race, white | 98 (79%) | 62 (84%) | 36 (72%) | .1 |
| BMI, kg/cm2, mean (range) | 27 (17–58) | 28 (20–58) | 27 (17–48) | .2 |
| Antibiotic allergy (any) | 27 (22%) | 20 (27%) | 7 (14%) | .09 |
| Penicillin allergy | 11 (9%) | 10 (14%) | 1 (2%) | .05 |
| Prior osteoarticular infection | 30 (24%) | 19 (26%) | 11 (22%) | .6 |
| Diabetes mellitus | 24 (19%) | 16 (22%) | 8 (16%) | .4 |
| Rheumatoid arthritis | 10 (8%) | 4 (5%) | 6 (12%) | .2 |
| Peripheral vascular disease | 8 (7%) | 8 (11%) | 0 | .02 |
| Degenerative joint disease | 23 (19%) | 12 (16%) | 11 (22%) | .4 |
| Renal insufficiency | 3 (2%) | 2 (3%) | 1 (2%) | >.99 |
| HIV infection | 1 (1%) | 0 | 1 (2%) | .4 |
| Current cancer | 4 (3%) | 2 (3%) | 2 (4%) | >.99 |
| Immunosuppression (steroids, immunomodulators, chemotherapy) | 13 (11%) | 5 (7%) | 8 (16%) | .1 |
| Current or former smoker | 45 (36%) | 31 (42%) | 14 (28%) | .1 |
| Orthopedic hardware on admission | 64 (52%) | 43 (58%) | 21 (42%) | .08 |
| Osteomyelitis | 90 (73%) | 51 (69%) | 39 (78%) | .3 |
| Septic arthritis | 57 (46%) | 33 (45%) | 24 (48%) | .7 |
| Fever on admission (>38.3°C) | 16 (13%) | 14 (19%) | 2 (4%) | .03 |
| Diagnostic indicators on admission | ||||
| Blood cultures drawn | 67 (54%) | 36 (49%) | 31 (62%) | .1 |
| ≥1 positive blood culture for MSSA | 25/67 (37%) | 12/36 (33%) | 13/31 (42%) | .5 |
| Radiography consistent with bone or joint infection | 43/96 (45%) | 25/57 (44%) | 18/39 (46%) | .8 |
| CT scan consistent with bone or joint infection | 23/33 (73%) | 11/14 (79%) | 13/19 (68%) | .5 |
| MRI consistent with bone or joint infection | 26/29 (90%) | 12/15 (80%) | 14/14 (100%) | .2 |
| Bone scan consistent with bone or joint infection | 7/9 (78%) | 3/5 (60%) | 4/4 (100%) | .4 |
| White blood cell count, K/mm3, median (range) | 10.4 (2.7–27.1) | 9.3 (2.7–25.2) | 10.6 (4.4–27.1) | .3 |
| Platelets, K/mm3, median (range) | 299 (14–1755) | 274 (14–1755) | 362 (113–749) | .002 |
| Serum creatinine, mg/dL, median (range) | 0.9 (0.5–9.0) | 0.9 (0.5–9.0) | 0.9 (0.5–4.3) | .2 |
| ESR, mm/h, median (range) | 65 (2–140) | 55 (2–140) | 82 (12–140) | .03 |
| CRP, mg/L, median (range) | 72 (0.2–445) | 60 (0.2–307) | 116 (0.8–445) | .07 |
| Serum glucose, mg/dL, median (range) | 112 (51–299) | 114 (51–299) | 107 (70–199) | .3 |
| Any surgical treatment | 110 (89%) | 67 (91%) | 43 (86%) | .4 |
| Outcomes | ||||
| Treatment successful at 3–6 months follow-up | 82/97 (85%) | 50/60 (83%) | 32/37 (86%) | .7 |
| Subset of osteomyelitis | 41/47 (87%) | 26/30 (87%) | 15/17 (88%) | >.99 |
| Subset of septic arthritis | 26/30 (87%) | 18/22 (82%) | 8/8 (100%) | .6 |
| Treatment successful at >6 months follow-up | 69/88 (78%) | 43/56 (77%) | 26/32 (81%) | .6 |
| Subset of osteomyelitis | 36/43 (84%) | 24/29 (83%) | 12/14 (86%) | >.99 |
| Subset of septic arthritis | 22/28 (79%) | 15/20 (75%) | 7/8 (88%) | .6 |
All values expressed as no. (%), unless otherwise indicated. Mixed septic arthritis and osteomyelitis infections were not considered in the comparison of subsets.
Abbreviations: BMI, body mass index; CRP, C-reactive protein; CT, computed tomography; ESR, erythrocyte sedimentation rate; HIV, human immunodeficiency virus; MRI, magnetic resonance imaging; MSSA, methicillin-susceptible Staphylococcus aureus; SD, standard deviation.