Does Subcutaneous Infiltration of Liposomal Bupivacaine Following Single-Level Transforaminal Lumbar Interbody Fusion Surgery Improve Immediate Postoperative Pain Control?

Study DesignRetrospective case-control study using prospectively collected data.PurposeEvaluate the impact of liposomal bupivacaine (LB) on postoperative pain management and narcotic use following standardized single-level low lumbar transforaminal lumbar interbody fusion (TLIF).Overview of LiteraturePoor pain control after surgery has been linked with decreased pain satisfaction and increased economic burden. Unfortunately, opioids have many limitations and side effects despite being the primary treatment of postoperative pain. LB may be a form of pre-emptive analgesia used to reduce the use of postoperative narcotics as evidence in other studies evaluating its use in single-level microdiskectomies.MethodsThe infiltration of LB subcutaneously during wound closure was performed by a single surgeon beginning in July 2014 for all single-level lumbar TLIF spinal surgeries at Landstuhl Regional Medical Center. This cohort was compared against a control cohort of patients who underwent the same surgery by the same surgeon in the preceding 6 months. Statistical analysis was performed on relevant variables including: morphine equivalents of narcotic medication used (primary outcome), length of hospitalization, Visual Analog Scale pain scores, and total time spent on a patient-controlled analgesia (PCA) pump.ResultsA total of 30 patients were included in this study; 16 were in the intervention cohort and 14 were in the control cohort. The morphine equivalents of intravenous narcotic use postoperatively were significantly less in the LB cohort from day of surgery to postoperative day 3. Although the differences lost their statistical significance, the trend remained for total (oral and intravenous) narcotic consumption to be lower in the LB group. The patients who received the study intervention required an acute pain service consult less frequently (62.5% in LB cohort vs. 78.6% in control cohort). The amount of time spent on a PCA pump in the LB group was 31 hours versus 47 hours in the control group (p=0.1506).ConclusionsLocal infiltration of LB postoperatively to the subcutaneous tissues during closure following TLIF significantly decreased the amount of intravenous narcotic medication required by patients. Well-powered prospective studies are still needed to determine optimal dosing and confirm benefits of LB on total narcotic consumption and other measures of pain control following major spinal surgery

Reducing surgical site infection in spinal surgery with betadine irrigation and intrawound vancomycin powder.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: The objective of this study was to evaluate the efficacy of a surgical site infection (SSI) prevention protocol instituted in the Orthopaedic Spine Department at our institution. SUMMARY OF BACKGROUND DATA: SSI is an undesired complication of orthopedic spine surgical procedures. It poses a significant risk to the patient, as well as a financial toll on the health care system. A wide range of prophylactic measures have been used to attempt to reduce SSI rates. METHODS: A protocol consisting of a combination of 0.3% Betadine wound irrigation and 1 g of intrawound Vancomycin powder application was developed at our institution. Multiple data sources were consolidated for thorough evaluation of changes in SSI rates, patient risk factors, and changes in bacteriology. Identification of risk factors that predispose patients to SSI was performed using mixed-effects logistic regression in a univariate fashion. Risk factors with P values of 0.05 or less in univariate analysis were included together in a multivariate mixed-effects logistic regression model. RESULTS: SSI rates were reduced by 50% after the intervention; χ analysis comparing the SSI rates between the pre- and postintervention periods yielded a P value of 0.042. Rates of methicillin-resistant Staphylococcus aureus dropped from 30% to 7% and the rates of multibacterial infections dropped from 37% to 27%. The risk factors that were statistically significant in multivariate analysis were the following: age (odds ratio [OR] = 0.93), anemia (OR = 30.73), prior operation (OR = 27.45), and vertebral fracture (OR = 22.22). CONCLUSION: The combination of Betadine wound irrigation and intrawound vancomycin powder application led to both a clinically and statistically significant decrease in SSI rates by 50%. Bacteriology analysis and risk factor assessment proved to be valuable tools in assessing the efficacy of a new prophylactic measure and in the planning of future protocols. LEVEL OF EVIDENCE: 4

Comparison of revision surgery for pseudarthrosis with or without adjacent segment disease after anterior cervical discectomy and fusion

Background: Patients with a pseudarthrosis after anterior cervical discectomy and fusion (ACDF) may have concurrent adjacent segment disease (ASD). Although prior studies have shown posterior cervical decompression and fusion (PCDF) is effective in repairing pseudarthrosis, improvement in patient reported outcomes (PROs) has been marginal. The aim of this study is to evaluate the effectiveness of PCDF in achieving symptom relief in patients with pseudarthrosis after ACDF and whether that is altered by the additional treatment of ASD. Methods: Thirty-two patients with pseudarthrosis were compared with 31 patients with pseudarthrosis and concurrent ASD after ACDF who underwent revision PCDF with a minimum 1-year follow-up. Primary outcomes measures included the neck disability index (NDI), and numerical rating scale (NRS) scores for neck and arm pain. Secondary measures included estimated blood loss (EBL), operating room (OR) time, and length of stay. Results: Demographics between cohorts were similar, however there was a significantly higher mean body mass index (BMI) in the group with concurrent ASD (32.23 vs. 27.76, p=.007). Patients with concurrent ASD had more levels fused during PCDF (3.7 vs. 1.9, p<.001), greater EBL (165 cc vs. 106 cc, p=.054), and longer OR time (256 minutes vs. 202 minutes, p<.000). Preoperative PROs for NDI (56.7 vs. 56.5, p=.954), NRS arm pain (5.9 vs. 5.7, p=.758), and NRS neck pain (6.6 vs. 6.8, p=.726) were similar in both cohorts. At 12 months patients with concurrent ASD experienced a slightly greater, but not statistically significant, improvement in PROs (Δ NDI 4.40 vs. -1.44, Δ NRS neck pain 1.17 vs. 0.42, Δ NRS arm pain 1.28 vs. 0.10, p=.107). Conclusions: PCDF is a standard procedure for treatment of pseudarthrosis following ACDF, however improvements in PROs are marginal. Slightly greater improvements were seen in patients whose indication for surgery also included concurrent ASD, rather than a diagnosis of pseudarthrosis alone

Advances in Quantitative FRET-Based Methods for Studying Nucleic Acids

Förster resonance energy transfer (FRET) is a powerful tool for monitoring molecular distances and interactions at the nanoscale level. The strong dependence of transfer efficiency on probe separation makes FRET perfectly suited for on/off experiments. To use FRET to obtain quantitative distances and three-dimensional structures, however, is more challenging. This review summarises recent studies and technological advances that have improved FRET as a quantitative molecular ruler in nucleic acid systems, both at the ensemble and at the single-molecule levels