Atypical Mycobacterial Infections of the Spine: Evaluation and Management.

BACKGROUND: Atypical mycobacterial infections of the spine can be difficult to treat and represent a subset of the vertebral osteomyelitis and diskitis spectrum often requiring early and aggressive surgical intervention. The purpose of this review is to improve the understanding of and approach to disease management from the perspective of the spine surgeon. MATERIALS AND METHODS: Debridement or excision of the affected levels may be necessary to decrease mycobacterial loads and restore biomechanics. A close relationship with the patient's internal medicine and infectious disease specialists should be maintained to ensure disease eradication or remission. Long-term suppressive antibiotic therapy may be required for infection control. RESULTS AND CONCLUSION: Atypical mycobacterial spine infections are rare, complex, and difficult to eradicate. Our institution proposes a collaborative effort among the spine surgeon, infectious disease specialists, and internal medicine specialists to best approach the work-up, diagnosis, and treatment of these infections. [Orthopedics. 2024;47(2):e61-e66.].

Alternative Uses of O-Arm and Stealth Navigation Technology Over 10 Years: The University of Colorado Experience.

Intraoperative computed tomography scanning with O-arm and use of Stealth navigation can improve surgical outcomes in a variety of orthopedic subspecialties. In spine surgery, the accuracy, precision, and safety of pedicle screw and interbody implant placement has improved. This technology is now routinely used in percutaneous pedicle screw placement and minimally invasive sacroiliac joint fusion. Other applications include, but are not limited to, isthmic pars defect repair, lumbosacral pseudoarticulation resection in Bertolotti's syndrome, radiofrequency ablation, and en bloc tumor resection. Intraoperative navigation has numerous applications, and use of this technology should continue to evolve as the technology advances. [Orthopedics. 2023;46(2):e89-e97.].

Opioid Prescription Monitoring in Preoperative and Postoperative Sacroiliac Joint Fusion Patients.

INTRODUCTION: An estimated 15%-25% of patients with chronic low back pain may in fact suffer from sacroiliac (SI) joint dysfunction. SI joint fusion has become a common treatment option for the management of SI joint dysfunction. However, little is known about opioid use prior to and after surgical treatment in this patient population. METHODS: The medical records of 62 patients treated with SI joint fusion at our institution were reviewed in this retrospective study. The Colorado Prescription Drug Monitoring Program (CPDMP) was accessed to gather opioid prescription information for these patients. Only those patients who had received an opioid prescription within 3 months prior to their surgery were included in the study. Patients who had SI joint fusion but underwent another surgical procedure during the 12-month follow-up period were excluded from analysis. Preoperative (6 and 3 months) and postoperative (3, 6, 9, and 12 months) mean morphine milligram equivalents (MME) were collected from the CPDMP database for each patient. Patient demographic and medical comorbidity data were also documented to identify any correlations or potential risk factors for chronic opioid prescribing. Visual analog scale (VAS), Oswestry Disability Index (ODI), and Denver SI Joint Questionnaire (DSIJQ) scores were recorded for each patient to assess clinical outcomes. RESULTS: At 3 months prior to surgery, patients were prescribed an average of 47.2 mean MME/d. At no point postoperatively did the quantity of opioids, measured in MME/d, change significantly from the 3-month preoperative prescription quantities. There was no significant difference in the quantity of opioids received by men vs women, in patients with vs without anxiety and/or depression, or in younger vs older patients. Low body mass index was correlated with decreased opioid prescriptions at 6 months postoperative but became statistically insignificant again by 9 months postoperative.Significant improvements in VAS scores were recorded for all postoperative clinical evaluation timepoints (at 6 weeks and 3, 6, and 12 months) and compared to preoperative scores. By 12 months, VAS scores had decreased from 6.2 to 3.9 (P < 0.001). This change is not only statistically significant but also meets the criteria for minimum clinically important difference in scores. Both the ODI and DSIJQ patient-reported outcomes scores also showed significant improvements at 12 months after surgery (ODI: 48.9 preoperative vs 24.6 postoperative, P = 0.02; DSIJQ: 53.2 preoperative vs 17.4 postoperative, P = 0.014). The ODI improvement also met the minimum clinically important difference criteria. By 6 months postoperatively, there was no significant correlation in VAS or ODI and opioid use. There was no significant correlation between the DSIJQ scores and the daily dose of opioids at any point postoperatively. CONCLUSION: Quantity of opioid prescriptions received by patients with SI joint pain did not change significantly from 3 months preoperatively to any point postoperatively despite significant improvements in all patient-reported outcome measures. This discordance between long-term opioid requirements and positive clinical outcomes is concerning and warrants further investigation.

The University of Colorado Virtual Physical Examination for Spine Surgeons: A Preliminary Study.

As coronavirus disease 2019 (COVID-19) reached pandemic status, in-person orthopedic clinics across the United States were forced to close as many states adopted stay-at-home orders. Previously, the use of telemedicine in orthopedic practices was minimal for a variety of reasons, one being the inability to perform a physical examination in a specialty reliant on direct patient contact for diagnosis and treatment. A prospective cohort of 52 patients consented to participate in a novel virtual physical examination protocol during routine telemedicine visits at a large, tertiary orthopedic spine practice. Participants were asked to perform a series of carefully designed physical maneuvers using readily available household objects to allow their provider to better assess sensory and motor function in the tele-medicine setting. Patients were then asked to complete a short satisfaction survey. In total, 52 patients completed the physical examination and survey. Males and females were distributed evenly among the cohort at 50%. The mean age was 52.1±15.5 years. The average score for ease of understanding the examination (1=easiest, 5=hardest) was 1.1, while the average score for ease of performance was 1.5. Most participants (97.56%) felt their provider was better able to understand their condition using the virtual examination findings. This study highlights the utility of a virtual physical examination for assessment of spine patients in the telemedicine setting. Furthermore, this study illustrates the ease with which such an examination can be implemented and performed to improve patient evaluation and satisfaction. [Orthopedics. 2022;45(1):e7-e10.].

Comparison of Adverse Outcomes Following Placement of Superion Interspinous Spacer Device Versus Laminectomy and Laminotomy.

BACKGROUND: Current evidence suggests placement of the Superion interspinous spacer (SISS) device compared with laminectomy or laminotomy surgery offers an effective, less invasive treatment option for patients with symptomatic lumbar spinal stenosis. Both SISS placement and laminectomy or laminotomy have risks of complications and a direct comparison of complications between the 2 procedures has not been previously studied. The purpose of this study is to compare the short-term complications of the SISS with laminectomy or laminotomy and highlight device-specific long-term outcomes with SISS. METHODS: Via retrospective review, 189 patients who received lumbar level SISSs were compared with 378 matched controls who underwent primary lumbar spine laminectomy or laminotomy; data were collected from the American College of Surgeons National Surgical Quality Improvement Program database. Complications analyzed included rates of wound infection, pulmonary embolism, deep venous thrombosis, urinary tract infection, sepsis, septic shock, cardiac arrest, death, and reoperation within 30 days of index surgery. Differences between groups were analyzed using the χ2test. Device-specific complication (DSC) rates included device malfunction or misplacement (DM), device explantation (DE), spinous process fracture (SPF), and subsequent spinal surgery (SSS). RESULTS: No differences in demographics or comorbidities existed between groups. There was no significant difference in rates of complications between groups. A total of 44.4% of patients in the SISS group experienced DSCs with 11.1% of patients experiencing DM, 21.1% experiencing an SPF, 20.1% requiring DE, and 24.3% requiring SSS. Having at least 1 DSC significantly increased odds of SSS, odds ratio >120, P < .0001. CONCLUSION: Rates of 30-day complications in the SISS group were not significantly different from patients undergoing laminectomy or laminotomy. Rates of 2-year DSC within SISS and cumulative risk associated with these complications should be considered further as they likely represent need for additional procedures for patients and substantial cost to the healthcare system. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: Having no differences in adverse events between laminectomies or laminotomies and SISS plus evidence of substantial device-specific long-term adverse outcomes and reoperation should be given consideration when deciding on surgical intervention of 1-2 level lumbar spinal stenosis.

Evaluation of Spinous Process Tethering at the Proximal End of Rigid Constructs: In Vitro Range of Motion and Intradiscal Pressure at Instrumented and Adjacent Levels.

BACKGROUND: Adult spinal deformity surgery requires use of long thoracolumbar instrumentation, which is associated with risk of postoperative proximal junctional kyphosis (PJK). Tethering has been used in spinal surgery but not around the spinous process (SP) in the context of preventing PJK. METHODS: Researchers applied a nondestructive hybrid loading protocol to 7 T8-L2 cadaveric specimens in flexion-extension, lateral bending, and axial rotation (AR). A rigid construct (pedicle screws and rods) and 1- and 2-level SP constructs were tested, as was a hand-tie technique. SP tethering (SPT) constructs use clamps on both sides of the SP; SPT helix constructs use 1 clamp and wrap around the SP. RESULTS: All tether constructs showed greater motion at the instrumented level and less motion at adjacent levels compared to rigid constructs. In AR, 1- and 2-level SPT constructs restricted first instrumented level motion to a greater extent when compared with other tether constructs (P ≤ .05). Passing the band through the T10 SP did not produce significant biomechanical differences compared to passing it through the T9-T10 interspinous ligament (P > .05). Hand-tied constructs demonstrated more motion compared to tensioned constructs (P > .05). Intradiscal pressure results corroborated motion data. CONCLUSIONS: SPT at the proximal end of a rigid construct produced more favorable biomechanical outcomes at instrumented and adjacent levels than were seen with a completely rigid construct. Clinical research is needed to determine whether these methods reduce the risk of PJK among patients. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: This work sheds light on the biomechanical stability of proximal tethering constructs in an effort to enhance the surgeon's ability to reduce rates of proximal junctional kyphosis and failure in thoracolumbar spinal fusion surgery.

Corrosion of Titanium Spinal Explants Is Similar to That Observed in Oil Field Line Pipe Steel: Evidence of Microbial-Influenced Corrosion In Vivo.

Current explanations of biomedical alloy degradation are focused on the physicochemical mechanisms of galvanic, pitting, crevice, and fretting corrosion. Ultimately, these studies dismiss the corrosion mechanism as a function of the local microbiome. Sixty spine hardware constructs were examined immediately after explantation for biofilm formation. Marked rod sections were imaged using scanning electron microscopy with energy dispersive x-ray spectroscopy. Backscatter mode was employed to better image the topology of the surface. There is clear differentiation between discoloration due to corrosion vs mechanical damage. Under scanning electron microscopy backscatter electron shadow examination, the authors noted that not all biofilm was removed using the surgical wipes. Corrosion pits were noticeably larger and numerous in areas of biofilm. In areas not associated with biofilms, there were few pits even if mechanical wear was evident. There is no evidence that the surface corrosion is modified between clinically diagnosed infected and noninfected patients. The surface damage present on explanted Ti6Al4V spine rods is uniquely similar to damage found in other industries where microbial-influenced corrosion is prevalent. Given that similar anaerobic, sulfur-reducing bacteria reside in and on human tissues, it is most likely that corrosion observed on explanted hardware is the result of microbial-influenced corrosion and not from inflammatory or other processes. Using analysis methods from other industries to characterize the microbiome present on explanted hardware is necessary. In so doing, a new definition of hardware-induced infection will be forthcoming. [Orthopedics. 2020;43(1):62-67.].

Early-Stage Chronic Kidney Disease and Hip Fracture Mortality.

Chronic kidney disease (CKD) is a documented risk factor for hip fracture mortality. CKD represents a spectrum of disease and there is no clear evidence differentiating the risk between patients with early versus end-stage CKD. The purpose of this study was to explore the relationship between the stages of CKD and mortality following operative treatment of hip fractures. Four hundred ninety-eight patients were analyzed; 81 were identified as having CKD. This study followed overall patient mortality at 90 days and at 1 year postoperatively. Patients with CKD had higher mortality at both 90 days and 1 year compared with those without CKD (hazard ratio 1.69 and 1.84, respectively). In a subgroup analysis to determine the effect of CKD stage, only stage 3 CKD was associated with increased mortality. The orthopaedic surgeon can play a key role in identifying at-risk patients and help to facilitate additional management. (Journal of Surgical Orthopaedic Advances 27(3):226-230, 2018).

Hip Fracture Mortality: Differences Between Intertrochanteric and Femoral Neck Fractures.

The purpose of this study was to identify the specific risk factors that affect mortality in patients with hip fractures and differentiate mortality-associated factors between intertrochanteric (IT) and femoral neck (FN) fractures. A total of 1538 consecutive patients with hip fractures were treated at the authors' institution between January 2005 and October 2013. Ultimately 858 IT and 479 FN fracture patients were included on the basis of age >60 years with an isolated hip fracture. Mortality rate at 90 days was 12.1% for IT and 9.6% for FN fractures. In both IT and FN fractures, variables associated with mortality risk include increased age, greater days to surgery, male gender, decreased body mass index, and increased American Society of Anesthesiologists score. When evaluated independently, the presence of cardiac arrhythmia and chronic kidney disease was strongly associated with greater mortality risk in FN fracture patients. The presence of chronic kidney disease and hypertension correlated with decreased mortality risk among FN fracture patients. (Journal of Surgical Orthopaedic Advances 27(1):64-71, 2018).

What's New in Pediatric Spine Growth Modulation and Implant Technology for Early-Onset Scoliosis?

BACKGROUND: Early-onset scoliosis (EOS) affects roughly 1 to 2 out of 10,000 live births per year. Because this subset of patients has a yet to achieve a majority of their skeletal growth, a number of treatment challenges need to be addressed before surgical intervention. If left untreated, EOS can cause a number of problems throughout the patient's lifespan, particularly in regards to the growth of the thorax and pulmonary development. A wide variety of surgical systems and techniques are available to the treating surgeon. METHODS: A review of the orthopaedic literature from 2010 to 2015 relating to pediatric spine growth modulation was performed. Ninety-eight papers were identified and, following exclusion criteria, a total of 31 papers were selected for further review. RESULTS: This paper summarizes the recently published literature regarding growth-friendly spinal implants, the status of their Food and Drug Administration approval labeling as well as the indications, applications, and complications associated with their implementation. CONCLUSIONS: There are a growing number of options at the surgeon's disposal when treating patients with EOS. As surgeons, we must continue to be vigilant in our demand for sound clinical evidence as we strive to provide optimal care for our patients. The rapidly advancing field of spinal growth modulation is exciting. More work must be done to further enhance our ability to predictably modulate growth in the pediatric spine.

Ultrasound findings in asymptomatic patients with modular metal on metal total hip arthroplasty.

OBJECTIVE: The use of metal-on-metal and modular total hip arthroplasty is associated with potentially serious local and systemic complications. The primary aim of this study was to identify the prevalence of a pseudotumor in asymptomatic patients with a particular metal-on-metal hip prosthesis after a minimum follow-up of 5 years using ultrasound evaluation. A secondary purpose was to identify associations between the presence of pseudotumor and serum metal ion levels following implantation. METHODS: We prospectively evaluated data collected from 36 asymptomatic patients who underwent implantation of a Profemur Z metal-on-metal total hip arthroplasty from January 2004 to January 2010. Serum metal ion levels were collected in 2012 and 2015. Hip ultrasounds were performed in 2015. RESULTS: Pseudotumors were found in 7/36 patients (19.4%). The average pseudotumor size measured 38.2 cm3 (range 7.35 cm3-130.81 cm3). Elevated metal ion levels were found in all patients at all time points. No statistical correlation was found between the presence of pseudotumor and patient age, age of the implant, component design, and any of the serum metal ion levels or ratios. CONCLUSIONS: One in every five asymptomatic patients with metal-on-metal implants was found to have a periarticular pseudotumor. There was no dose-dependent relationship found between elevated serum metal ion levels and the development of a pseudotumor. Our findings suggest that in patients with known elevated metal ion levels, continued monitoring of ion levels may not be a reliable predictor of pseudotumor formation, and ultrasound surveillance can and should be routinely used to document the presence and progression of pseudotumor.

Effect of Body Mass Index on Blood Transfusion in Total Hip and Knee Arthroplasty.

Perioperative blood management remains a challenge during total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to systematically examine the relationship between body mass index (BMI) and perioperative blood transfusion during THA and TKA while attempting to resolve conflicting results in previously published studies. The authors retrospectively evaluated 2399 patients, 896 of whom underwent THA and 1503 of whom underwent TKA. Various outcome variables were assessed for their relationship to BMI, which was stratified using the World Health Organization classification scheme (normal, <25 kg/m(2); overweight, 25-30 kg/m(2); obese, >30 kg/m(2)). Among patients undergoing THA, transfusion rates were 34.8%, 27.6%, and 21.9% for normal, overweight, and obese patients, respectively (P=.002). Among patients undergoing TKA, transfusion rates were 17.3%, 11.4%, and 8.3% for normal, overweight, and obese patients, respectively (P=.002). Patients with an elevated BMI have decreased rates of blood transfusion following both THA and TKA. This same cohort also loses a significantly decreased percentage of estimated blood volume. No trends were identified for a relationship between BMI and deep venous thrombosis, pulmonary embolism, myocardial infarction, discharge location, length of stay, 30-day readmission rate, and preoperative hemoglobin level. Elevated BMI was significantly associated with increased estimated blood loss in patients undergoing THA and those undergoing TKA. There was a statistically significant trend toward increased deep surgical-site infection in patients undergoing THA (P=.043). Patients with increased BMI have lower rates of blood transfusion and lose a significantly smaller percentage of estimated blood volume following THA and TKA. [Orthopedics.2016; 39(5):e844-e849.].

Verification of nerve decompression using mechanomyography.

BACKGROUND CONTEXT: Assessment of nerve root decompression in surgery is largely based on visualization and tactile feedback. Often times, visualization can be limited, such as in minimally invasive surgery, and tactile feedback is a subjective assessment that makes the evaluation of successful nerve decompression difficult. Electromyography (EMG) has been proposed as an assessment tool, but EMG responses are often difficult to quantify. Alternatively, mechanomyography (MMG) provides a quantifiable response with high signal-to-noise ratio compared with EMG. MMG provides a sensitive tool to accurately quantify mechanical responses to motor action potentials generated by electrical stimulus, allowing more reliable assessment of nerve decompression. PURPOSE: The aim of this study was to assess the ability of MMG to quantitatively demonstrate successful nerve root decompression. STUDY DESIGN: Prospective cohort, Therapeutic Level III, Urban Level I Trauma Center. PATIENT SAMPLE: A total of 46 patients (72 affected nerve roots) undergoing decompression procedures for lower extremity radiculopathy caused by nerve root compression were enrolled in the study. The study population included 15 patients with herniated nucleus pulposus (HNP) and 31 with lateral recess stenosis (LRS). OUTCOME MEASURE: Visual analog scale (VAS) score. METHODS: A total of 72 nerves roots in 46 patients undergoing lumbar decompression procedures, for lower extremity radicular symptoms, were tested using MMG. Nerves were stimulated upstream from the compression site, and the lowest threshold current needed to generate a muscle response was determined. Signal response sizes were recorded before and after decompression. VAS scores were collected pre- and postoperatively. RESULTS: Of the patients, 90% (65/72) had elevated stimulation thresholds (>1 milliamp [mA]) before decompression. After decompression, 98% of patients (64/65) with elevated current thresholds exhibited a drop in threshold of ≥1 mA (p<.001). A postdecompression increase in response amplitude was recorded in all patients. VAS scores improved postdecompression (6.8 vs. 1.1, p<.001) with a positive correlation between decreased stimulation thresholds and degree of improvement in VAS scores (p<.001). CONCLUSION: MMG is an effective tool that can be used to differentiate normal and compressed nerves by quantifying the mechanomyographic response to a stimulating current. MMG allows one to measure the effect of decompression, judge its effectiveness in real time, and eliminate the subjectivity seen in tactile feedback methods. When the adequacy of decompression is uncertain, MMG can guide the surgeon toward additional or alternative procedures to ensure complete nerve root decompression.

Rivaroxaban Versus Enoxaparin for Venous Thromboembolism Prophylaxis after Hip and Knee Arthroplasty.

The oral Factor Xa inhibitor rivaroxaban (Xarelto) has been the pharmacologic agent used for venous thromboembolism (VTE) prophylaxis after primary hip and knee arthroplasty (THA/TKA) at our institution since February 2012. The purpose of our study was to compare rates of VTE and major bleeding between rivaroxaban and our previous protocol of enoxaparin after THA/TKA. A retrospective cohort study was performed including 2406 consecutive patients at our institution between 1/1/11 and 9/30/13. Patients who did not have unilateral primary THA/TKA or who received other anticoagulants were excluded. Of the 1762 patients included, 1113 patients (63.2%) received enoxaparin and 649 patients (36.8%) received rivaroxaban. This study found no demonstrable differences between these two anticoagulants in rates of VTE, infection, reoperation, transfusion, or major bleeding. Therapeutic, Retrospective comparative study, Level III.

Predictors and complications of blood transfusion in total hip and knee arthroplasty.

Perioperative patient optimization can minimize the need for blood transfusions in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to determine predictors and complications of transfusions. This retrospective review analyzed 1795 patients who underwent primary THA and TKA at our institution between January 2011 and December 2012. Of the 1573 patients ultimately included the rates of transfusion were 9.27% in TKA and 26.6% in THA. Significant predictors for transfusion include: preoperative hemoglobin, age, female gender, body mass index, creatinine, TKA, operating room time, operative blood loss, and intra-operative fluids. The DVT rate was comparable, but deep surgical site infection rate among transfused patients was 2.4% compared to 0.5% in non-transfused patients (P = 0.0065).

A field evaluation of four larval mosquito control methods in urban catch basins.

Effective control of mosquitoes in rural Midwestern communities that lack organized mosquito control districts would be aided by baseline data on optimal breeding sites, interannual effects of climate on population emergence and abundance, and efficacy of various control options under field conditions. During 19 surveillance weeks in the summer of 2005, we sampled 100 catch basins each week that were distributed among 10 study zones. Catch basins within each study zone were subjected to 1 of 4 different mosquito control methods or were left untreated. Of the 10 study zones, 5 were in high-intensity urban areas and 5 in low-intensity urban areas. During the study period, treatment of urban catch basins with Altosid XR extended residual briquets resulted in a 69.5% reduction in mosquito larvae numbers. However, the product did not provide sustained treatment for the 120-150 days suggested by the manufacturer. Vectolex WSP, when applied according to manufacturer's suggestions, resulted in a 73.4% reduction in mosquito larvae. VectolexWSP effectiveness was impacted by heavy rainfalls early in the surveillance period. Cleaning catch basins once or twice during the surveillance period resulted in a 40.1% and a 39.9% reduction in mosquito larvae, respectively. Catch basins in high-intensity urban areas comprised 27.7% of the total collection compared to 72.3% from low-intensity urban areas. The AltosidXR extended residual briquets and the VectolexWSP products both impacted the number of mosquito larvae collected. However, a single treatment to control mosquitoes in this study area may not be sufficient. We suggest that treatment of urban catch basins is optimized when accompanied by a comprehensive surveillance plan, and that a combination of treatments or multiple treatments during the season may be necessary to mitigate risks of vector-borne infectious diseases in areas with similar climate and precipitation trends.