Management of late (>1 y) deep infection after spinal fusion: a retrospective cohort study.

BACKGROUND: The incidence of late infection published in the literature varies from 1% to 12% with varying definition of late infection (range, 3 mo to 1 y). Current evidence suggests implant removal and antibiotic therapy is necessary to clear these infections. A high incidence of late (>1 y) deep infection after instrumented spinal fusion was identified at our institution. We sought to evaluate the efficacy of our management of these patients. METHODS: A total of 1390 patients underwent instrumented spinal fusion from 2000 to 2009. Forty-two patients developed deep infection >1 year after index procedure (3%) and had surgical debridement. Clinical records and microbiology reports were reviewed for details of operative and postoperative management. RESULTS: Advanced imaging was only obtained in 6 patients (5 computed tomography, 1 magnetic resonance imaging). Offending organisms were identified in 39/42 patients, 27 of these grew Propionibacterium acnes. P. acnes grew in culture at a median of 6 days (range, 3 to 10 d), significantly longer than all other organisms, which grew in a median of 1 day (range, 0 to 8 d) (P<0.001). Implants were removed at the index hospitalization in 41 patients. Implant retention was attempted in 1 patient and failed. Primary closure was carried out in 37 patients; the remainder had undergone multiple debridements (4 planned, 1 unplanned). VAC closure was utilized in 2 patients. All patients were treated with organism-specific intravenous antibiotics and transitioned to oral antibiotics on average in 34 days (range, 2 to 186 d). Total length of antibiotic therapy was an average of 141 days (range, 34 to 413 d). CONCLUSIONS: P. acnes was the most common organism identified and took nearly 1 week to grow in culture. Treatment is generally successful with thorough debridement, removal of implants, and antibiotic treatment. LEVEL III: retrospective comparative study.

Are routine postoperative radiographs necessary during the first year after posterior spinal fusion for idiopathic scoliosis? A retrospective cohort analysis of implant failure and surgery revision rates.

BACKGROUND: Radiographs are routinely obtained at postoperative visits during the first year after posterior spinal fusion (PSF) for idiopathic scoliosis (IS). The goal of this study was to determine how often radiographic findings change postoperative care. METHODS: A total of 227 consecutive patients aged 10 to 21 years who underwent surgery for IS at our institution from 2004 to 2010 were identified. Charts were reviewed to determine the frequency of the following clinical symptoms during the first year after surgery: pain greater than expected, implant prominence, and sensory/motor disturbance. Radiographs were reviewed to identify implant failure and curve change. Logistic regression analysis was used to identify clinical symptoms associated with treatment deviation. RESULTS: During the first year after surgery, an average of 6 (range, 2 to 12) radiographs were obtained from patients during an average of 3 (range, 2 to 10) follow-up visits. Pain (14%) was the most common symptom. Neurologic symptoms (13%) and implant prominence (4%) were less common. Implant failure was identified in 4 subjects (2%), of which 3 required revision surgery. The incidence of revision surgery was 2.9/1000 radiographs (95% confidence interval, 0.6-8.3). Curve progression >5 degrees in the uninstrumented curve occurred in 2 patients (0.9%). Curve progression did not result in a change in treatment for any of the patients. Pain was the only clinical symptom associated with implant failure (P=0.0047). 169/227 patients did not have any symptoms and only one of these underwent revision surgery. The sensitivity of a clinical test, which uses the presence of pain to guide the need for radiographic evaluation and rule out implant failure, was 75%, specificity 87%, positive predictive value 10%, and negative predictive value 99.5%. CONCLUSIONS: After obtaining baseline postoperative radiographs, additional radiographs during the first year after surgery for IS may not be required in the absence of clinical symptoms. Reducing the number of radiographs taken during the first year after surgery for IS in patients without symptoms can reduce radiation exposure to patients and health care costs without affecting treatment. LEVEL OF EVIDENCE: Level II, Diagnostic Study.

Wound complications of vertical expandable prosthetic titanium rib incisions.

STUDY DESIGN: Multicenter retrospective review. OBJECTIVE: To compare the incidence of infection between vertical expandable prosthetic titanium rib (VEPTR) incision locations and determine if the infection risk increases in relation to presence of previous incisions and/or increased number of times incisions are opened. SUMMARY OF BACKGROUND DATA: Patients undergoing treatment for chest and spine deformity with VEPTR require multiple incisions that are opened repeatedly during expansion procedures. METHODS: A prospective database (7 sites) and institutional database (2 sites), were queried to identify their 20 most recent patients with VEPTR with a minimum of 4 expansions for inclusion. A total of 103 patients were identified. Clinical and operative reports were reviewed to determine incision locations, number, and infection complications. RESULTS: Twenty-five of 103 patients (24%) developed an infection during treatment. Six had multiple infections (range, 2-4), providing a total of 34 infection events. Patients averaged 6.4 expansion procedures and 13 total incisions. Infection rate at each incision site was not significantly different, in the range from 1% to 5%: paramedian (6 infections/23 patients with total 185 incisions, 3%), proximal midline (12/39; 224, 5%), thoracotomy (6/61; 455, 1%), iliac (5/37; 143, 4%), and distal midline (5/58; 148, 3%). Infection events occurred after an average of 3 times a particular incision was opened (95% confidence interval: 2.2-3.8). There was a trend toward higher infection rate with increased number of times a particular incision was opened. There was no increased infection rate in patients with surgical incisions prior to VEPTR (26%; 6/23) compared with patients not having prior incisions (24%; 19/80). CONCLUSION: The incidence of infection in patients with 4 or more VEPTR lengthenings was 24% and did not differ across the various incision locations. Presence of prior surgical incisions was not a risk factor for infection. Surgeons should use the most appropriate incision in relation to their patient's pathology when using VEPTR while remaining vigilant for infection. LEVEL OF EVIDENCE: 3.