The utility of disc space and vertebral body specimens cell count differential for the diagnosis of native vertebral osteomyelitis: a prospective cohort study.

BACKGROUND: Diagnostic methods for native vertebral osteomyelitis (NVO) often yield inconclusive results. Image-guided spine biopsies for culture are specific but diagnose NVO in only 50% of cases. Pre-exposure to antimicrobials further reduces diagnostic yield. Our study assesses the value of neutrophil percentage in disc space fluid and vertebral body (DS/VB) samples for diagnosing NVO. METHODS: Adults referred for spine biopsy at Mayo Clinic from August 2022 to September 2023 were consented and enrolled at the time of biopsy. Following routine specimen collection, the biopsy needle was rinsed in saline into an EDTA tube for cell analysis. NVO diagnosis required organism identification in spine tissue or blood and/or positive histopathology, and consistent symptoms and imaging. RESULTS: Sixty-eight patients were prospectively enrolled, comprising 14 with NVO and 54 with alternative diagnoses. The median biopsy sample polymorphonuclear (PMN) percentage for NVO patients was 80.5% (IQR 72.5-85.2), compared to 64.5% (IQR 54.0-69.0) for those without NVO (p < 0.001). Nine (64.3%) NVO patients received antibiotics within 10 days prior to spine biopsy. As a continuous measure, PMN differential showed a moderately strong ability in classifying NVO status with an area under ROC curve of 0.795; an optimal point on the curve of 71.5% corresponded to a sensitivity of 78.6%, specificity of 79.6%, negative predictive value of 93.5% and positive predictive value of 50.0%. CONCLUSION: PMN differential in DS/VB biopsies may serve as an effective diagnostic tool in the evaluation of patients with NVO particularly in ambiguous cases with an initially negative spine biopsy. Future efforts will aim to implement these findings within routine clinical practice.

2015 Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Diagnosis and Treatment of Native Vertebral Osteomyelitis in Adults.

These guidelines are intended for use by infectious disease specialists, orthopedic surgeons, neurosurgeons, radiologists, and other healthcare professionals who care for patients with native vertebral osteomyelitis (NVO). They include evidence and opinion-based recommendations for the diagnosis and management of patients with NVO treated with antimicrobial therapy, with or without surgical intervention.

Executive Summary: 2015 Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Diagnosis and Treatment of Native Vertebral Osteomyelitis in Adults.

These guidelines are intended for use by infectious disease specialists, orthopedic surgeons, neurosurgeons, radiologists, and other healthcare professionals who care for patients with native vertebral osteomyelitis (NVO). They include evidence and opinion-based recommendations for the diagnosis and management of patients with NVO treated with antimicrobial therapy, with or without surgical intervention.

The Effect of Quantitative Computed Tomography Acquisition Protocols on Bone Mineral Density Estimation.

Osteoporosis is characterized by bony material loss and decreased bone strength leading to a significant increase in fracture risk. Patient-specific quantitative computed tomography (QCT) finite element (FE) models may be used to predict fracture under physiological loading. Material properties for the FE models used to predict fracture are obtained by converting grayscale values from the CT into volumetric bone mineral density (vBMD) using calibration phantoms. If there are any variations arising from the CT acquisition protocol, vBMD estimation and material property assignment could be affected, thus, affecting fracture risk prediction. We hypothesized that material property assignments may be dependent on scanning and postprocessing settings including voltage, current, and reconstruction kernel, thus potentially having an effect in fracture risk prediction. A rabbit femur and a standard calibration phantom were imaged by QCT using different protocols. Cortical and cancellous regions were segmented, their average Hounsfield unit (HU) values obtained and converted to vBMD. Estimated vBMD for the cortical and cancellous regions were affected by voltage and kernel but not by current. Our study demonstrated that there exists a significant variation in the estimated vBMD values obtained with different scanning acquisitions. In addition, the large noise differences observed utilizing different scanning parameters could have an important negative effect on small subregions containing fewer voxels.

Factors Related to Clinical Performance in Spine Surgery Fellowship: Can We Predict Success.

INTRODUCTION: The factors most important in the spine fellowship match may not ultimately correlate with quality of performance during fellowship. This study examined the spine fellow applicant metrics correlated with high application rank compared with the metrics associated with the strongest clinical performance during fellowship. METHODS: Spine fellow applications at three academic institutions were retrieved from the San Francisco Match database (first available to 2021) and deidentified for application review. Application metrics pertaining to research, academics, education, extracurriculars, leadership, examinations, career interests, and letter of recommendations were extracted. Attending spine surgeons involved in spine fellow selection at their institutions were sent a survey to rank (1) fellow applicants based on their perceived candidacy and (2) the strength of performance of their previous fellows. Pearson correlation assessed the associations of application metrics with theoretical fellow rank and actual performance. RESULTS: A total of 37 spine fellow applications were included (Institution A: 15, Institution B: 12, Institution C: 10), rated by 14 spine surgeons (Institution A: 6, Institution B: 4, Institution C: 4). Theoretical fellow rank demonstrated a moderate positive association with overall research, residency program rank, recommendation writer H-index, US Medical Licensing Examination (USMLE) scores, and journal reviewer positions. Actual fellow performance demonstrated a moderate positive association with residency program rank, recommendation writer H-index, USMLE scores, and journal reviewer positions. Linear regressions identified journal reviewer positions (ß = 1.73, P = 0.002), Step 1 (ß = 0.09, P = 0.010) and Step 3 (ß = 0.10, P = 0.002) scores, recommendation writer H-index (ß = 0.06, P = 0.029, and ß = 0.07, P = 0.006), and overall research (ß = 0.01, P = 0.005) as predictors of theoretical rank. Recommendation writer H-index (ß = 0.21, P = 0.030) and Alpha Omega Alpha achievement (ß = 6.88, P = 0.021) predicted actual performance. CONCLUSION: Residency program reputation, USMLE scores, and a recommendation from an established spine surgeon were important in application review and performance during fellowship. Research productivity, although important during application review, was not predictive of fellow performance. LEVEL OF EVIDENCE: III. STUDY DESIGN: Cohort Study.

Defeating the Hidden Foe: Antibiotic Therapy and Clinical Outcomes of Cutibacterium acnes Spinal Implant Infections.

Background: Cutibacterium acnes can cause spinal implant infections. However, little is known about the optimal medical management and outcomes of C. acnes spinal implant infections (CSII). Our study aims to describe the management of patients with CSII and evaluate the clinical outcomes. Methods: We performed a retrospective cohort study of patients aged 18 years or older who underwent spinal fusion surgery with instrumentation between January 1, 2011, and December 31, 2020, and whose intraoperative cultures were positive for C. acnes. The primary outcome was treatment failure based on subsequent recurrence, infection with another organism, or unplanned surgery secondary to infection. Results: There were 55 patients with a median follow-up (interquartile range) of 2 (1.2-2.0) years. Overall, there were 6 treatment failures over 85.8 total person-years, for an annual rate of 7.0% (95% CI, 2.6%-15.2%). Systemic antibiotic treatment was given to 74.5% (n = 41) of patients for a median duration of 352 days. In the subgroup treated with systemic antibiotics, there were 4 treatment failures (annual rate, 6.3%; 95% CI, 1.7%-16.2%), all of which occurred while on antibiotic therapy. Two failures occurred in the subgroup without antibiotic treatment (annual rate, 8.8%; 95% CI, 1.1%-31.8%). Conclusions: Our study found that the estimated annual treatment failure rate was slightly higher among patients who did not receive antibiotics. Of the 6 failures observed, 4 had recurrence of C. acnes either on initial or subsequent treatment failures. More studies are warranted to determine the optimal duration of therapy for CSII.

LEF-1 is a prosurvival factor in chronic lymphocytic leukemia and is expressed in the preleukemic state of monoclonal B-cell lymphocytosis.

The canonical Wnt signaling pathway is pathogenic in a variety of cancers. We previously identified aberrant expression of the Wnt pathway transcription factor and target gene lymphoid enhancer binding factor-1 (LEF1) in chronic lymphocytic leukemia (CLL). This suggested that the Wnt signaling pathway has a role in the biology of CLL. In this study, we performed a Wnt pathway analysis using gene expression profiling and identified aberrant regulation of Wnt pathway target genes, ligands, and signaling members in CLL cells. Furthermore, we identified aberrant protein expression of LEF-1 specifically in CLL but not in normal mature B-cell subsets or after B-cell activation. Using the T cell-specific transcription factor/LEF (TCF/LEF) dual luciferase reporter assay, we demonstrated constitutive Wnt pathway activation in CLL, although the pathway was inactive in normal peripheral B cells. Importantly, LEF-1 knockdown decreased CLL B-cell survival. We also identified LEF-1 expression in CD19(+)/CD5(+) cells obtained from patients with monoclonal B-cell lymphocytosis, suggesting a role for LEF-1 early in CLL leukemogenesis. This study has identified the constitutive activation and prosurvival function of LEF-1 and the Wnt pathway in CLL and uncovered a possible role for these factors in the preleukemic state of monoclonal B-cell lymphocytosis.

The structure of the TNFRSF13C promoter enables differential expression of BAFF-R during B cell ontogeny and terminal differentiation.

The B cell-activating factor of the TNF family receptor (BAFF-R), encoded by the TNFRSF13C gene, is critically important for transitional B cell survival to maturity. Thus, ligation of BAFF-R by BAFF delivers a potent survival signal. Reports implicating the BAFF/BAFF-R signaling axis in the pathogenesis of autoimmune human diseases and B lineage malignancies have largely prompted studies focusing on BAFF expression; however, there is an equally critical need to better understand BAFF-R expression. Initial BAFF-R expression, although characterized in murine B cells, has not yet been reported in human B lymphopoiesis. In this study, we first demonstrate that BAFF-R expression is absent from early precursors and is acquired by bone marrow B cells newly expressing the BCR. We next focused on identifying the specific genomic region that controls BAFF-R expression in mature B cells (i.e., the TNFRSF13C promoter). To accomplish this, we used in silico tools examining interspecies genomic conservation in conjunction with reporter constructs transfected into malignant B and plasma cell lines. DNase protection assays using nuclear extracts from BAFF-R-expressing cells suggested potential regulatory sites, which allowed the generation of EMSA probes that bound NFs specific to BAFF-R-expressing cells. With a more stringent analysis of interspecies homology, these assays identified a site at which a single nucleotide substitution could distinctly impact promoter activity. Finally, chromatin immunoprecipitation assays revealed the in vivo binding of the specific transcription factor c-Rel to the most proximal genomic region, and c-Rel small interfering RNA transfections in BAFF-R-expressing lines demonstrated a coincident knockdown of both c-Rel and BAFF-R mRNA.

Infection not associated with use of human musculoskeletal tissue allografts.

The deaths of otherwise healthy patients that are attributable to contaminated allografts have heightened concerns about the screening, processing, and use of such tissues. We present one tertiary care institution's experience with musculoskeletal allografts and determine the frequency of postoperative Clostridium infection. We used an institutional microbiology database to identify all records of culture-confirmed Clostridium infection from January 1990 through July 2006. A comprehensive musculoskeletal database was cross-referenced to include all possible allograft samples surgically collected or implanted from January 1990 through July 2004 to determine the frequency of Clostridium infection associated with use of allograft musculoskeletal tissue. Musculoskeletal allografts were implanted in 16,314 patients during the study period. After a minimum follow-up of 2 years, no patient had development of a definite Clostridium infection that was attributable to the use of musculoskeletal allograft tissue. These outcomes can be achieved with established screening and processing techniques for donor tissue.

Sacral Insufficiency Fracture Following Short-Segment Lumbosacral Fusion: Case Series and Review of the Literature.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Sacral insufficiency fracture is a rare and serious complication following lumbar spine instrumented fusion. The purpose of this study was to describe the patient characteristics, presentation, evaluation, treatment options, and outcomes for patients with sacral insufficiency fracture after short-segment lumbosacral fusion. METHODS: Six patients from our institutional database and 16 patients from literature review were identified with a sacral insufficiency fracture after short-segment (L4-S1 or L5-S1) lumbar fusion within 1 year of surgery. RESULTS: Patients were 55% female with a mean age of 58 years and body mass index of 30 kg/m2. Osteoporosis or osteopenia was the most common comorbidity (85%). Half of patients sustained a sacral fracture after surgery from a posterior approach, while the others had anterior or anterior-posterior surgery. Mean time to fracture was 42 days with patients clinically presenting with new sacral pain (86%), radiculopathy (60%), or neurologic deficit (5%). Ultimately, 73% of patients underwent operative fixation often involving extension of the construct (75%) and fusion to the pelvis (69%). Men (P = .02) and patients with new radicular pain or neurologic deficit (P = .01) were more likely to undergo revision surgical treatment while women over 50 years of age were more likely to be treated conservatively (P = .003). CONCLUSIONS: Spine surgeons should monitor for sacral insufficiency fracture as a source of new-onset pain in the postoperative period in patients with a short segment fusion to the sacrum. The recognition of this complication should prompt an assessment of bone health and management of underlying bone fragility.

Body mass index and the impact on hospital resource use in patients undergoing total knee arthroplasty.

We identified all total knee arthroplasty patients between 1996 and 2004 and classified them by preoperative body mass index (BMI) as normal (BMI, 18.5-24.9 kg/m(2)), overweight (BMI, 25.0-29.9 kg/m(2)), obese (30-34.9 kg/m(2)), or morbidly obese (≥ 35.0 kg/m(2)). Of 5521 patients, 769 had a normal BMI, 1938 were overweight, 1539 were obese, and 1275 were morbidly obese. Adjusted length of stay was no different between normal (4.85 days), overweight (4.84 days), obese (4.86 days), or morbidly obese patients (4.93 days) (P = .30). Overall costs were similar among normal ($15,386), overweight ($15,430), obese ($15,646), or morbidly obese patients ($15,752) (P = .24). Postsurgical costs were no different among normal ($9860), overweight ($9889), obese ($10,063), or morbidly obese patients ($10,136) (P = .44). Our results suggest that increased BMI does not lead to increased hospital resource use for total knee arthroplasty.

Implant Sonication versus Tissue Culture for the Diagnosis of Spinal Implant Infection.

MINI: We compared the sensitivity and specificity of peri-implant tissue culture to the vortexing-sonication technique for the diagnosis of spinal implant infection (SII). Lower thresholds of sonicate fluid culture positivity showed increased sensitivity with maintained specificity. We recommend a threshold of 20 CFU/10 mL for sonicate culture positivity for the diagnosis of SII. STUDY DESIGN: This is a retrospective study comparing the diagnosis of spinal implant infection (SII) by peri-implant tissue culture to vortexing-sonication of retrieved spinal implants. OBJECTIVE: We hypothesized that vortexing-sonication would be more sensitive than peri-implant tissue culture. SUMMARY OF BACKGROUND DATA: We previously showed implant vortexing-sonication followed by culture to be more sensitive than standard peri-implant tissue culture for diagnosing of SII. In this follow-up study, we analyzed the largest sample size available in the literature to compare these two culture methods and evaluated thresholds for positivity for sonicate fluid for SII diagnosis. METHODS: We compared peri-implant tissue culture to the vortexing-sonication technique which samples bacterial biofilm on the surface of retrieved spinal implants. We evaluated different thresholds for sonicate fluid positivity and assessed the sensitivity and specificity of the two culture methods for the diagnosis of SII. RESULTS: A total of 152 patients were studied. With more than 100 colony forming units (CFU)/10 mL as a threshold for sonicate fluid culture positivity, there were 46 patients with SII. The sensitivities of peri-implant tissue and sonicate fluid culture were 65.2% and 79.6%; the specificities were 88.7% and 93.4%, respectively. With more than 50 CFU/10 mL as a threshold, there were 50 patients with SII. The sensitivities of peri-implant tissue and sonicate fluid culture were 68.0% and 76.0%; the specificities were 92.2% for both methods. Finally, with more than or equal to 20 CFU/10 mL as a threshold, there were 52 patients with SII. The sensitivities of peri-implant tissue and sonicate fluid culture were 69.2% and 82.7%; the specificities were 94.0% and 92.0%, respectively. CONCLUSION: Implant sonication followed by culture is a sensitive and specific method for the diagnosis of SII. Lower thresholds for defining sonicate fluid culture positivity allow for increased sensitivity with a minimal decrease in specificity, enhancing the clinical utility of implant sonication. LEVEL OF EVIDENCE: 4.

This is a retrospective study comparing the diagnosis of spinal implant infection (SII) by peri-implant tissue culture to vortexing­sonication of retrieved spinal implants. We hypothesized that vortexing­sonication would be more sensitive than peri-implant tissue culture. We previously showed implant vortexing­sonication followed by culture to be more sensitive than standard peri-implant tissue culture for diagnosing of SII. In this follow-up study, we analyzed the largest sample size available in the literature to compare these two culture methods and evaluated thresholds for positivity for sonicate fluid for SII diagnosis. We compared peri-implant tissue culture to the vortexing­sonication technique which samples bacterial biofilm on the surface of retrieved spinal implants. We evaluated different thresholds for sonicate fluid positivity and assessed the sensitivity and specificity of the two culture methods for the diagnosis of SII. A total of 152 patients were studied. With more than 100 colony forming units (CFU)/10 mL as a threshold for sonicate fluid culture positivity, there were 46 patients with SII. The sensitivities of peri-implant tissue and sonicate fluid culture were 65.2% and 79.6%; the specificities were 88.7% and 93.4%, respectively. With more than 50 CFU/10 mL as a threshold, there were 50 patients with SII. The sensitivities of peri-implant tissue and sonicate fluid culture were 68.0% and 76.0%; the specificities were 92.2% for both methods. Finally, with more than or equal to 20 CFU/10 mL as a threshold, there were 52 patients with SII. The sensitivities of peri-implant tissue and sonicate fluid culture were 69.2% and 82.7%; the specificities were 94.0% and 92.0%, respectively. Implant sonication followed by culture is a sensitive and specific method for the diagnosis of SII. Lower thresholds for defining sonicate fluid culture positivity allow for increased sensitivity with a minimal decrease in specificity, enhancing the clinical utility of implant sonication. Level of Evidence: 4.

The System Is Broken: A Qualitative Assessment of Opioid Prescribing Practices After Spine Surgery.

OBJECTIVE: To elucidate factors that influence opioid prescribing behaviors of key stakeholders after major spine surgery, with a focus on barriers to optimized prescribing. METHODS: In-person semi-structured interviews were performed with 20 surgical and medical professionals (January 23, 2019 to June 11, 2019) at a large academic medical center, including resident physicians, midlevel providers, attending physicians, and clinical pharmacists. Interviews centered on perceptions of postoperative prescribing practices were coded and analyzed using a qualitative inductive approach. RESULTS: Several unique themes emerged. First, wide interprovider variation exists in the perceived role of opioid prescribing guidelines. Second, there are important relationships between clinical experience, time constraints, and postoperative opioid prescribing. Third, opioid tapering is a major area of inconsistency. Fourth, there are serious challenges in managing analgesic expectations, particularly in those with chronic pain. Finally, there is currently no process to facilitate the hand-off or transition of opioid prescribing responsibility between surgical and primary care teams, which represents a major area for practice optimization efforts. CONCLUSION: Despite increased focus on postoperative opioid prescribing, there remain numerous areas for improvement. The development of tools and processes to address critical gaps in postoperative prescribing will be essential for our efforts to reduce long-term opioid use after major spine surgery and improve patient care.

Association Between Spine Surgery and Availability of Opioid Medication.

Importance: Prolonged prescribing of opioids after spine surgery is often perceived as a negative outcome, but successful opioid reduction may occur despite continued prescribing. Improved characterization of opioid availability before and after surgery is necessary to identify these successes. Objective: To evaluate the association between spine surgery and modification of opioid availability postoperatively by using consistent definitions to classify opioid availability before and after surgery. Design, Setting, and Participants: This population-based cohort study included 2223 adults (age ≥18 years) who underwent spine surgery in Olmsted County, Minnesota, from January 1, 2005, through December 31, 2016. Data were analyzed from April 1, 2019, to December 1, 2019. Exposures: Preoperative opioid availability based on prescription data in the 180 days before surgery in accordance with Consortium to Study Opioid Risks and Trends (CONSORT) definitions. Main Outcomes and Measures: Successful modification of opioid availability, defined as an improvement in CONSORT status postoperatively (assessed from 181 to 365 days after surgery) compared with preoperative status, or continued absence of opioid availability for patients with no preoperative availability. Multivariable logistic regression was used to assess the association between preoperative opioid availability and successful modification by 1 year after undergoing surgery. Results: Of 2223 patients included in the study, 1214 were male (54.6%), with a median age of 55 years (interquartile range, 43-68) years. Patients were classified as having no (778 [35.0%]), short-term (1118 [50.3%]), episodic (227 [10.2%]), or long-term (100 [4.5%]) preoperative opioid availability. Of the 2148 patients (96.6%) who were alive at 1 year, postoperative opioid availability was classified as no (1583 [73.7%]), short-term (398 [18.5%]), episodic (104 [4.8%]), and long-term (63 [2.9%]). A total of 1672 patients (77.8%) had successful modification of opioid availability, with success of 83.0% for those with no preoperative availability, 74.9% for those with short-term preoperative availability, 79.8% for those with episodic preoperative availability, and 64.4% for those with long-term preoperative opioid availability. In multivariable analysis, success was significantly associated with preoperative opioid availability (odds ratio [OR] for short term, 0.61 [95% CI, 0.48-0.77]; OR for episodic, 0.95 [95% CI, 0.64-1.40]; OR long term, 0.49 [95% CI, 0.30-0.82]; P < .001 overall vs no availability). Conclusions and Relevance: In this study, when following standardized CONSORT definitions, 4 of 5 adults undergoing spine surgery in a population-based cohort met the criteria for a successful pattern of postoperative opioid prescribing. Similar methods to objectively assess changes in opioid prescribing may be clinically useful in other perioperative settings.

Impact of body mass on hospital resource use in total hip arthroplasty.

OBJECTIVE: To determine the impact of BMI on post-operative outcomes and resource utilization following elective total hip arthroplasty (THA). DESIGN: A retrospective cohort analysis on all primary elective THA patients between 1996 and 2004. Primary outcomes investigated using regression analyses included length of stay (LOS) and costs (US dollars). SETTING: Mayo Clinic Rochester, a tertiary care centre. SUBJECTS: Patients were stratified by pre-operative BMI as normal (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), obese (30.0-34.9 kg/m(2)) and morbidly obese (> or =35.0 kg/m(2)). Of 5642 patients, 1362 (24.1 %) patients had a normal BMI, 2146 (38.0 %) were overweight, 1342 (23.8 %) were obese and 792 (14.0 %) were morbidly obese. RESULTS: Adjusted LOS was similar among normal (4.99 d), overweight (5.00 d), obese (5.02 d) and morbidly obese (5.17 d) patients (P = 0.20). Adjusted overall episode costs were no different (P = 0.23) between the groups of normal ($17,211), overweight ($17,462), obese ($17,195) and morbidly obese ($17,655) patients. Overall operative and anaesthesia costs were higher in the morbidly obese group ($5688) than in normal ($5553), overweight ($5549) and obese ($5593) patients (P = 0.03). Operating room costs were higher in morbidly obese patients ($3418) than in normal ($3276), overweight ($3291) and obese ($3340) patients (P < 0.001). Post-operative costs were no different (P = 0.30). Blood bank costs differed (P = 0.002) and were lower in the morbidly obese group ($180) compared with the other patient groups (P < 0.05). Other differences in costs were not significant. Morbidly obese patients were more likely to be transferred to a nursing home (24.1 %) than normal (18.4 %), overweight (17.9 %) or obese (16.0 %) patients (P = 0.001 each). There were no differences in the composite endpoint of 30 d mortality, re-admissions, re-operations or intensive care unit utilization. CONCLUSIONS: BMI in patients undergoing primary elective THA did not impact LOS or overall institutional acute care costs, despite higher operative costs in morbidly obese patients. Obesity does not increase resource utilization for elective THA.

Mechanical strength of bone allografts subjected to chemical sterilization and other terminal processing methods.

Infectious disease transmission through the use of human donor allografts can be a catastrophic complication in an otherwise straightforward surgical procedure. The use of bone allograft in reconstructive orthopedic surgeries is increasing, yet severe complications, including death, can result if the transplanted tissues transmit a communicable disease to the tissue recipient. The BioCleanse tissue sterilization process is a fully automated, low-temperature chemical sterilization process that renders allograft tissue sterile. The purpose of this study was to evaluate the effect of a chemical tissue sterilization process on the mechanical strength of cortical bone allografts prior to implantation. Cylindrical cortical bone specimens were harvested from seven human cadaver donors and treated either by: chemical sterilization alone; chemical sterilization and terminal sterilization by gamma irradiation; chemical sterilization, lyophilization, terminal sterilization by STERRAD and rehydration; or untreated. The specimens were tested to failure in axial compression, diametral compression, shear, or bending. There were no significant differences in ultimate stress, strain, or fracture energy between the chemically sterilized and control groups in any of the testing modes.

Anatomical variations of the iliolumbar vein with application to the anterior retroperitoneal approach to the lumbar spine: a cadaver study.

Objectives of this study include identification of lumbosacral venous variations, designation of a critical area of dissection for surgical exposure, and comparison between both male/female and right/left-sided anatomy. Attempts were made to provide anatomic nomenclature that accurately describes these structures. Thirty-eight iliolumbar venous systems in 20 cadavers (11 females/9 males) were dissected. Each system was identified as one of three patterns of variation: common venous trunk (combining ascending lumbar and iliolumbar venous systems) with distal veins, common venous trunk without distal veins, and venous systems without a common venous trunk. Dimensions including distances to the inferior vena cava (IVC) confluence, the obturator nerve, and the lumbosacral trunk, and venous stem length were obtained to aid surgical dissection. Differences between males and females and those between right and left sides were compared. Anterior lumbosacral venous variations could be organized into three groups. A Type 1 venous system (common venous trunk with distal veins) was most common (53% of systems). The anatomical name "lateral lumbosacral veins" adequately describes the anatomical location of these veins and does not assume a direction of venous flow or the lack of individual distal veins. A critical area bordered by the obturator nerve anteriorly, the psoas muscle laterally, the spinal column medially, and sacrum posteriorly within 8.2 cm of the IVC confluence should be defined to adequately dissect the lateral lumbosacral veins. Differences in male and female lateral lumbosacral venous anatomy do not alter surgeon's approach to the anterior lumbar spine.

"The Jackson Table Is a Pain in the ": A Qualitative Study of Providers' Perception Toward a Spinal Surgery Table.

OBJECTIVE: The aim of this study was to define health care providers' perceptions toward prone patient positioning for spine surgery using the Jackson Table, which has not been hitherto explored. METHODS: We analyzed open-ended questionnaire data and interviews conducted with the spine surgical team regarding the current process of spinal positioning/repositioning using the Jackson Table. Participants were asked to provide an open-ended explanation as to whether they think the current process of spinal positioning/repositioning is safe for the staff or patients. Follow-up qualitative interviews were conducted with 11 of the participants to gain an in-depth understanding of the challenges and safety issues related to prone patient positioning. RESULTS: Data analysis resulted in 6 main categories: general challenges with patient positioning, role-specific challenges, challenges with the Jackson Table and the "sandwich" mechanism, safety concerns for patients, safety concerns for the medical staff, and recommendations for best practices. CONCLUSIONS: This study is relevant to everyday practice for spinal surgical team members and advances our understanding of how surgical teams qualitatively view the current process of patient positioning for spinal surgery. Providers recommended best practices for using the Jackson Table, which can be achieved through standardized practice for transfer of patients, educational tools, and checklists for equipment before patient transfer and positioning. This research has identified several important practice opportunities for improving provider and patient safety in spine surgery.

The management and outcome of spinal implant infections: contemporary retrospective cohort study.

BACKGROUND: Spinal implant infections provide unique diagnostic and therapeutic challenges. METHODS: We conducted a retrospective cohort study to evaluate risk factors for treatment failure in patients with early- and late-onset spinal implant infections at the Mayo Clinic (Rochester, MN) during 1994-2002. RESULTS: We identified 30 patients with early-onset spinal implant infection and 51 patients with late-onset spinal implant infection. Twenty-eight of 30 patients with early-onset infection were treated with debridement, implant retention, and antimicrobial therapy. The estimated 2-year cumulative probability of survival free of treatment failure for patients with early-onset infection was 71% (95% confidence interval [CI], 51%-85%). Thirty-two of 51 patients with late-onset infection were treated with implant removal. Their estimated 2-year cumulative probability of survival free of treatment failure was 84% (95% CI, 66%-93%). For patients with early-onset infections, receiving oral antimicrobial suppression therapy was associated with increased cumulative probability of survival (hazard ratio, 0.2; 95% CI, 0.1-0.7). For patients with late-onset infections, implant removal was associated with increased cumulative probability of survival (hazard ratio, 0.3; 95% CI, 0.1-0.7). CONCLUSIONS: Early-onset spinal implant infections are successfully treated with debridement, implant retention, and parenteral followed by oral suppressive antimicrobial therapy. Implant removal is associated with successful outcomes in late-onset infections.

Mechanical properties of patellar tendon allografts subjected to chemical sterilization.

PURPOSE: We tested the hypothesis that the preimplantation mechanical properties of BioCleanse-treated bone-patellar tendon-bone (BPTB) allografts are not significantly different from those of untreated specimens. METHODS: For this controlled laboratory study, specimens were harvested as central third or hemi-BPTB units from both knees of 17 cadaveric tissue donors (11 men and 6 women) aged 19 to 88 years. Donor-matched specimens (20 per group) were randomly assigned to either BioCleanse-treated or untreated control groups. Specimens were subjected to 25 minutes of pretensioning at 89 N and then cyclically loaded under longitudinal tension between 50 N and 250 N for 1,000 cycles at 1 Hz, followed by ramp to failure at 50 mm/min. RESULTS: No statistically significant difference was found between untreated and BioCleanse-treated specimens in stiffness (235.3 +/- 37.6 N/mm v 222.3 +/- 53.4 N/mm, P = .37), cyclic creep (0.38 +/- 0.42 mm v 0.40 +/- 0.26 mm, P = .81), maximum force (1,685.7 +/- 471.6 N v 1,807.0 +/- 657.8 N, P = .47), or ultimate stress (29.0 +/- 9.8 MPa v 29.0 +/- 12.8 MPa, P = .98). CONCLUSIONS: The preimplantation mechanical properties of BPTB allografts treated with BioCleanse are not significantly different from those of untreated controls. CLINICAL RELEVANCE: This laboratory study compares the biomechanical properties of chemically treated allografts, which are currently being used in anterior cruciate ligament reconstruction, with those of nontreated fresh-frozen allografts.