Is Propionibacterium acnes becoming the most common bacteria in delayed infections following adolescent idiopathic scoliosis surgery?

STUDY DESIGN: Retrospective review of hospital charts. OBJECTIVE: (1) To determine the microbiological profile of patients with surgical site infections following posterior spinal fusion surgery (PSF) for Adolescent Idiopathic scoliosis (AIS). (2) To study the treatment outcome of patients with surgical site infections (SSI) following surgery for AIS. (3) To identify the key differences in presentation and management of acute and delayed SSI following AIS surgery. There has been increasing evidence of the role of P. acnes in deep surgical site infections. Literature related to this is abundant in relation to shoulder arthroplasty; however, it is sparse in relation to spine surgery. METHODS: We conducted a retrospective review of all patients treated for AIS during a 5-year period (2010-2014) at our institution, with a minimum of 2-year follow-up after the index surgery. Patients with a postoperative infection following their index surgery were included. Charts of AIS patients with post-op infections were reviewed for details of the index surgery, time to presentation of the infection, presenting signs/symptoms, microbiology details, details of surgical and antibiotic treatment, and outcomes. RESULTS: Nine (2.8%) post-op infections were identified out of 315 cases for AIS during this period. Seven (2.2%) involved P. acnes. Two (0.6%) involved MSSA. The average time for cultures to show growth was 6.1 days (range 5-8 days) in P. acnes group and 2-3 days in MSSA group. Patients with P. acnes infections were treated with implant removal, debridement and antibiotics. All patients achieved solid fusion except two patients from the P. acnes group had pseudoarthrosis and had to undergo revision fusion. CONCLUSION: Propionibacterium acnes was the single most common bacteria isolated from delayed surgical site infection following PSF in AIS patients. Optimal treatment consists of debridement, implant removal and antibiotics. These patients have high incidence of pseudoarthrosis. LEVEL OF EVIDENCE: Level IV.

Pre-operative methicillin resistant Staphylococcus aureus results do not predict surgical site infections in children undergoing varus derotational osteotomy.

Literature regarding the value of pre-operative nasal methicillin resistant Staphylococcus aureus (MRSA) swabs to predict surgical site infections (SSIs) in children undergoing lower extremity surgery is limited. The purpose of our study was to determine if pre-operative nasal MRSA swab results were predictive of SSI development in children undergoing a femoral varus derotational osteotomy (VDRO).Patients who underwent VDRO between 2004-2016 were reviewed to determine pre-operative MRSA colonization rates and SSI devolvement rates. Patients with less than 1 year of follow-up, previous history of infections, or absent pre-operative MRSA swab were excluded. SSI rates of patients with negative MRSA and positive MRSA swab result were compared using the Fisher exact test. Aside from contact isolation precautions, no other changes in treatment were made during inpatient hospital course based on positive pre-operative nasal MRSA swab results.247 patients met the inclusion criteria (mean age: 9.3 ±â€Š3.6 years, 62% male). There were 242 (98%) patients with a negative MRSA swab and 5 (2%) patients with a positive MRSA swab. Out of the 242 patients with a negative MRSA swab, 4 developed an SSI. Of the patients with positive MRSA swab results, 0% (0/5) developed an SSI compared to 1.7% (4/242) of negative MRSA swab results who developed an SSI. Results indicated no significant difference in SSI development rates between the groups (P = 1.00).In this series of children undergoing VDRO surgery, the results of a pre-operative MRSA nasal swab had no relationship to SSI incidence and no impact on clinical patient care. Pre-operative MRSA nasal swabs appear to be of limited benefit for routine pre-operative screening in this patient population.Level III, retrospective comparative.