Geometric analysis of pedicle subtraction osteotomy (PSO) for Kyphosis correction: anterior lengthening may occur at the osteotomized body as well as at the discs above and below.

OBJECTIVE: To validate the authors kyphosis correction formula for pedicle subtraction osteotomy (PSO) cases. Additionally, to use the formula to evaluate the safety of PSO by determining if there is anterior lengthening. METHODS: Twenty-two patients with primarily kyphosis corrected by PSO and with clear landmarks on preoperative and postoperative x-rays were selected. Several anatomical lines and angle measurements were utilized as depicted previously in the Vertebral Column Resection formula (see below). Two approximations were calculated: the geometric approximation (G) = (tanG°*2 + 1)*15° and the rough approximation (R) which is about the same amount of actual shortening (x), if parallel length (y) ≥ 40; twice of x, if y < 40. For each patient, the change of segmental kyphosis angle (K°) was measured and compared with G° and R°, and the correlation between each value was analyzed. RESULTS: The absolute Mean ± SE for K - G and K - R was 2.33° ± 0.34 and 6.09° ± 0.58, respectively. K - G is < 3° (p = 0.03). K - R is < 8° (p = 0.001). In other words, K was close to G and R and thus can be predicted by these approximations. Average posterior shortening, anterior shortening, and kyphosis correction at each level were 20.8 ± 2.0 mm, - 3.64 ± 1.5 mm (which equates to anterior lengthening), and 31.05° ± 2.0, respectively. Anterior lengthening occurred in 13 cases (in 4 cases, both at the body as well as at the disc above and below.) The correlation between posterior and anterior shortening was 0.03 (p = 0.88). There were 3 cage insertion cases: 1 had anterior lengthening, while 2 had anterior shortening even with the cage. CONCLUSION: This study validated the geometric and rough approximations originally used in PVCR patients, for PSO patients. Additionally, this study found that anterior lengthening may occur in PSOs usually at the discs, but occasionally at the osteotomized body.

Sacroiliac joint dysfunction: pathophysiology, diagnosis, and treatment.

PURPOSE: To review the anatomy and function of the sacroiliac joint (SIJ), as well as the pathophysiology, clinical presentation, diagnostic criteria, and treatment options for SIJ dysfunction. METHODS: The SIJ serves an extremely crucial function in mobility, stability, and resistance against shear forces. Joint mobility becomes increasingly limited with age-related cartilaginous changes that begin in puberty and continue throughout life. Pain can also be localized to the SIJ itself, known as SIJ dysfunction. A literature review was performed on the anatomy, etiology, risk factors, diagnostic modalities, and treatment options for SIJ dysfunction. RESULTS: SIJ dysfunction is an under-recognized source of low back pain. Dysfunction can result from various clinical conditions, as well as abnormal motion or malalignment of the joint. Diagnosis and evaluation of SIJ dysfunction are difficult, with use of physical maneuvers and image-guided anesthetic injection. Non-operative treatment options are considered first-line due to high surgical complication rates. Such options include conservative management, radiofrequency treatment, nerve blocks, and articular injections. Surgical management involves open and percutaneous approaches. CONCLUSION: With the aging nature of the population, SIJ dysfunction has emerged as an extremely prevalent issue. Current research into the pathophysiology and risk factors of SIJ dysfunction is extremely important for planning preventative and therapeutic strategies. Various treatment options exist including conservative management, radiofrequency, nerve blocks, intra-articular or peri-articular injections, and surgical fixation. Improved diagnostic methods in clinical practice are thus critical to properly identify patients suffering from SIJ dysfunction, plan early intervention, and hasten return to function. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

The Effect of Ball Milling on Properties and Consolidation of Nanostructured ZrB2.

ZrB2 powders were milled using high-energy ball for various durations and consolidated using the pulsed current activated sintering (PCAS). The effects of milling on the sintering behavior and crystallite size ZrO2 powders were investigated. A nanostructured dense ZrB2 specimen with a relative density of up to 97% was readily achieved within 3 min. The ball milling effectively refined the crystallite structure of ZrB2 powders and facilitated the subsequent consolidation. The sinter-onset temperature was reduced appreciably by the prior milling for 10 h. Accordingly, the relative density of ZrB2 compact increases as the milling time increases. The hardness and fracture toughness of sintered ZrB2 increased as the density increases.

A review of lumbosacral transitional vertebrae and associated vertebral numeration.

PURPOSE: To review the current literature on methods of accurate numeration of vertebral segments in patients with Lumbosacral transitional vertebrae (LSTVs). LSTVs are a common congenital anomaly of the L5-S1 junction. While their clinical significance has been debated, unquestionable is the need for their identification prior to spinal surgery. We hypothesize that there are no reliable landmarks by which we can accurately number transitional vertebrae, and thus a full spinal radiograph is required. METHODS: A Pubmed and EMBASE search using various combinations of specific key words including "LSTV", "lumbosacral transitional vertebrae", "count", "vertebral numbering", and "number" was performed. RESULTS: The gold standard for spinal segment numeration in patients with LSTV remains whole spine imaging and counting caudally, starting from C2. If whole spine imaging is not available, the use of the iliac crest tangent sign on coronal magnetic resonance imaging (MRI) has fairly reliable sensitivity and specificity (81 and 64-88%, respectively) for accurate numeration of LSTV. The role of paraspinal anatomic markers such as the right renal artery, superior mesenteric artery, aortic bifurcation, and conus medullaris, for identification of vertebral levels is unreliable and should not be used. CONCLUSIONS: A sagittal whole spine view should be added as a scout view when patients obtain lumbar MRI to standardize the vertebral numbering technique. To date, there has been no other method for accurate numeration of a transitional vertebral segment, other than counting caudally from C2. These slides can be retrieved under Electronic Supplementary Material.

The etiology of congenital scoliosis: genetic vs. environmental-a report of three monozygotic twin cases.

PURPOSE: To describe the presence of congenital scoliosis in a genetically identical population as it relates to the possible genetic vs. environmental etiologic factors. METHODS: The authors describe three cases of congenital scoliosis in monozygotic twins. The first pair includes two 4-year-old girls presenting with mirror curves, one of whom had an associated stage I Chiari malformation. The second pair is a 4-year-old girl who presented with thoracic scoliosis, a T10-11 hemivertebra, and multilevel failure of segmentation in the lumbar spine whose identical sibling is unaffected. The third pair includes a 4-month-old boy with T9 and L4 hemivertebra whose brother is also unaffected. RESULTS: All three cases were managed conservatively with observation and remained asymptomatic throughout the duration of follow-up. There were no associations with extraspinal deformities, although one patient presented with concomitant type I Chiari malformation. CONCLUSION: The variable presentation of congenital scoliosis in a genetically unique population serves as testament to the complexity associated with its development, likely involving both environmental factors and a genetic predisposition.

Bone graft materials for posterolateral fusion made simple: a systematic review.

BACKGROUND: Iliac crest has long been the gold standard for lumbar fusion, but concerns over donor site morbidity have led to a wide variety of bone graft substitutes. Despite prolific research, a general consensus is yet to be reached on bone graft materials that lead to optimal fusion. PURPOSE: The purpose of this review is to evaluate the current literature for bone graft material options that maximize fusion rate in posterolateral lumbar fusion surgery. DESIGN: Systematic Review. METHODS: A PRISMA-compliant systematic review of PubMed, EMBASE, and the Web of Science was conducted. Included studies were published from January 2000 to July 2015, were clinical human research studies involving available autograft, allograft, or synthetic bone graft options in posterolateral lumbar spine fusion, and reported radiographic fusion rate as a primary end outcome. This research had no funding source and the authors have no conflicts to declare. RESULTS: 81 articles underwent full-text review, and 48 were included in this study. 18 studies assessed fusion rate by plain radiographs alone (37.5%), while 6 used CT scan (12.5%), and 24 used both (50.0%). 45 studies looked at ICBG in conjunction with LAG (29), BCP(1), APC (2), BMPs (6), or DBM (1). Aggregate mean fusion rates among these ranged from 68.0 to 91.5%. 22 studies evaluated fusion rates of LAG, either isolated (3) or combined with ceramic extenders (8), DBM (4), BMP (1), BMA (4), APC (1), or ICBG(1). Aggregate mean fusion rate ranged from 75 to 95.5%. With the exception of studies involving allograft (mean fusion rate 40.0%), the mean fusion rate for all other graft combinations exceeded 70.0%. CONCLUSIONS: While our results find that LAG+BMA provided highest fusion rate, most material options analyzed in this study provide comparable fusion outcomes. The ideal graft option must incorporate a combination of materials with osteoconductive, osteoinductive, and osteogenic properties. Our results represent the robust and dynamic nature of the current state of lumbar graft technology. These slides can be retrieved under Electronic Supplementary Material.

A 1.15 µW 200 kS/s 10-b Monotonic SAR ADC Using Dual On-Chip Calibrations and Accuracy Enhancement Techniques.

Herein, we present an energy efficient successive-approximation-register (SAR) analog-to-digital converter (ADC) featuring on-chip dual calibration and various accuracy-enhancement techniques. The dual calibration technique is realized in an energy and area-efficient manner for comparator offset calibration (COC) and digital-to-analog converter (DAC) capacitor mismatch calibration. The calibration of common-mode (CM) dependent comparator offset is performed without using separate circuit blocks by reusing the DAC for generating calibration signals. The calibration of the DAC mismatch is efficiently performed by reusing the comparator for delay-based mismatch detection. For accuracy enhancement, we propose new circuit techniques for a comparator, a sampling switch, and a DAC capacitor. An improved dynamic latched comparator is proposed with kick-back suppression and CM dependent offset calibration. An accuracy-enhanced bootstrap sampling switch suppresses the leakage-induced error <180 µV and the sampling error <150 µV. The energy-efficient monotonic switching technique is effectively combined with thermometer coding, which reduces the settling error in the DAC. The ADC is realized using a 0.18 µm complementary metal⁻oxide⁻semiconductor (CMOS) process in an area of 0.28 mm². At the sampling rate fS = 9 kS/s, the proposed ADC achieves a signal-to-noise and distortion ratio (SNDR) of 55.5 dB and a spurious-free dynamic range (SFDR) of 70.6 dB. The proposed dual calibration technique improves the SFDR by 12.7 dB. Consuming 1.15 µW at fS = 200 kS/s, the ADC achieves an SNDR of 55.9 dB and an SFDR of 60.3 dB with a figure-of-merit of 11.4 fJ/conversion-step.

Radiofrequency ablation of benign thyroid nodules: depicting early sign of regrowth by calculating vital volume.

OBJECTIVE: We evaluated long-term follow-up results of radiofrequency ablation of benign thyroid nodules to analyse the role of marginal vital tissue on nodule regrowth. MATERIALS AND METHODS: We reviewed the medical records of 54 patients who underwent radiofrequency ablation between June 2008 and November 2013 with pressure symptoms, and/or cosmetic problems. All patients were followed up at least 12 months on three occasions. To evaluate an early sign of regrowth, three types of nodule volumes (total volume, ablated volume and vital volume) were measured and calculated using ultrasonography. Regrowth was defined as a more than a 50% increase in the total volume and vital volume increase was defined as a more than 50% increase compared to the previously reported smallest volume on ultrasonography. RESULTS: The mean follow-up period was 39.4 ± 21.7 (range, 13-87) months. Vital volume increases occurred in 31 nodules (57.4%) and there was regrowth in 13 nodules (24.1%). The mean timing of the vital volume increase was 27.5 ± 18.5 months, and for regrowth it was 39.9 ± 17.5 months. Vital volume increase tended to precede regrowth. CONCLUSION: Vital volume increase tended to occur earlier than regrowth and might be an early sign of regrowth in following-up after the radiofrequency ablation of benign thyroid nodules.

Ultrasound-guided core needle biopsy of cervical lymph nodes in the diagnosis of toxoplasmosis.

BACKGROUND: Our study investigates whether the histopathological features of toxoplasmic lymphadenitis (TL), specifically noncaseating microgranuloma and follicular hyperplasia, can be obtained by sonographic-guided core needle biopsy (CNB) of cervical lymph nodes. METHODS: Thirty-two patients seen from June 2014 to March 2015 were positive for toxoplasma immunoglobulin M antibody. Among those patients, 21 underwent CNB of a cervical lymph node and were enrolled in this study. The pathologic findings were reviewed. RESULTS: Twenty-nine lymph nodes in 21 patients were sampled. Eighteen of the 21 (86%) patients had a microgranuloma without caseating necrosis or giant cells, and all 21 (100%) patients had follicular hyperplasia. CONCLUSIONS: The histologic findings of TL were detected by sonographic-guided CNB, which can be used as part of the first line of investigation in patients with unexplained cervical adenopathy. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:192-196, 2017.

Guided Bone Regeneration Using Demineralized Dentin Matrix: Long-Term Follow-Up.

PURPOSE: This case report reviews the long-term clinical outcomes of using demineralized dentin matrix (autogenous tooth bone graft material [AutoBT]) in 5 cases that were first reported in 2010. MATERIALS AND METHODS: Cone-beam computerized tomography was used to measure the height and width of the graft to determine the change in bone area from immediately after surgery to final follow-up (average, 5 yr 5.8 months). Corticocancellous bone formation and marginal bone resorption also were evaluated histologically 3 to 6 months after grafting, which focused mainly on remodeling capacities. RESULTS: Decreases in buccal height and alveolar ridge width ranged from -0.4 to -3.3 mm and from -0.4 to -4.2 mm, respectively. The change in bone area ranged from -8.1 to -36.2%. Corticocancellous bone had formed and was maintained successfully except for 1 mm of buccal marginal bone resorption in 1 case followed for 6 years 7 months. CONCLUSION: AutoBT, which was first reported for guided bone regeneration, showed that the corticocancellous bone that had formed had been maintained successfully with an implant after an average follow-up of 5 years. Although the number of samples was small, the results were consistent with those of other short-term follow-up studies on AutoBT.

Transoral sonographic diagnosis of submandibular duct calculi.

We present a case of submandibular duct calculi diagnosed using transoral sonography. Sonography is the first-line imaging modality of salivary gland calculi. However, it is performed via a transcutaneous approach, which is limited in identifying small salivary duct calculi. Using an intraoral transducer, transoral sonography can visualize the submandibular duct and detect the presence of small calculi, thus overcoming the limitations of transcutaneous sonography.

Axial lumbar interbody fusion (AxiaLIF) approach for adult scoliosis.

BACKGROUND: AxiaLIF was initially advocated as a minimally invasive, presacral lumbar fusion approach. Its use has expanded in to adult scoliosis surgeries. METHODS: Current literature about AxiaLIF for degenerative lumbar surgery and adult scoliosis surgery were reviewed. Anatomy, biomechanical properties, clinical results, and complications were summarized. RESULTS: Anatomically, AxiaLIF is relatively safe even though traversing blood vessels, and the pelvic splanchnic nerve can be at risk. AxiaLIF can provide significant stiffness compared to the intact spine, but posterior supplementation is recommended. AxiaLIF in the long construct for adult scoliosis surgeries can protect the S1 screw as effectively as pelvic fixation. Successful clinical outcomes after AxiaLIF were reported in the degenerative lumbar spine, adult scoliosis, and spondylolisthesis. It can facilitate a high fusion rate up to 96 % without BMP. Complications include pseudarthrosis, rectal injury, transient nerve irritation, and intrapelvic hematoma. CONCLUSION: AxiaLIF is a relatively safe procedure, and it provides good clinical results in both short constructs and long constructs for adult scoliosis surgery. For a safer procedure, surgeons should seek out prior colorectal surgical history and review preoperative imaging studies carefully.

Transoral sonographic diagnosis of tonsilloliths: report of 3 cases.

Tonsilloliths are calcified concretions that develop in tonsillar crypts. They are usually asymptomatic; however, they may cause problems such as halitosis, dysphagia, a globus sensation, and otalgia. Tonsilloliths may be diagnosed by a simple inspection or palpation of tonsillar crypts, which can be confirmed by panoramic radiography, computed tomography, or magnetic resonance imaging. We report 3 cases of tonsilloliths diagnosed by transoral sonography that was performed easily and comfortably in an office-based setting.

An In Vitro Biomechanical Analysis of Contralateral Sacroiliac Joint Motion Following Unilateral Sacroiliac Stabilization with and without Lumbosacral Fixation.

STUDY DESIGN: Cadaveric biomechanics study. PURPOSE: This study investigated the effects of unilateral sacroiliac joint (SIJ) fixation for fusion with/without L5-S1 fixation on contralateral SIJ range of motion (ROM). OVERVIEW OF LITERATURE: SIJ fusion raises concerns that unilateral SIJ stabilization for fusion may increase contralateral SIJ mobility, leading to accelerated SIJ degeneration. Also, prior lumbosacral fixation may lead to accelerated SIJ degeneration, due to adjacent level effects. SIJ fixation biomechanics have been evaluated, showing a reduced-ROM, but SIJ fixation effects on contralateral nonfixated SIJ remain unknown. METHODS: Seven human lumbopelvic spines were used, each affixed to six-degrees-of-freedom testing apparatus; 8.5-Nm pure unconstrained bending moments applied in flexion-extension, lateral bending, and axial rotation. The ROM of left and right SIJ was measured using a motion analysis system. Each specimen tested as (1) intact, (2) injury (left), (3) L5-S1 fixation, (4) unilateral stabilization (left), (5) unilateral stabilization+L5-S1 fixation, (6) bilateral stabilization, and (7) bilateral stabilization+L5-S1 fixation. Both left-sided iliosacral and posterior ligaments were cut for injury condition to model SIJ instability before surgery. RESULTS: There were no statistical differences between fixated and contralateral nonfixated SIJ ROM following unilateral stabilization with/without L5-S1 fixation for all loading directions (p>0.930). Injured condition and L5-S1 fixation provided the largest motion increases across both joints; no significant differences were recorded between SIJs in any loading direction (p>0.850). Unilateral and bilateral stabilization with/without L5-S1 fixation reduced ROM compared with the injured condition for both SIJs, with bilateral stabilization providing maximum stability. CONCLUSIONS: In the cadaveric model, unilateral SIJ stabilization with/without lumbosacral fixation did not lead to significant contralateral SIJ hypermobility; long-term changes and in vivo response may differ.

Does anterior shoulder balance in adolescent idiopathic scoliosis correlate with posterior shoulder balance clinically and radiographically?

PURPOSE: Patients with adolescent idiopathic scoliosis (AIS) often present with a disfiguring shoulder imbalance. Shoulder balance (Sh.B) is of significant importance to the patient's self-perception. Previous studies have correlated Sh.B with respect to only the clinical posterior view correlated with radiographs. It is important, however, to address Sh.B with respect to anterior view of the patients' shoulders as if patients were viewing in a mirror. In this study, we evaluated the anterior Sh.B and correlated it with posterior Sh.B clinically and radiographically in Lenke type 1 and 2 curves. METHOD: An online scoliosis database was queried to identify 74 AIS patients with Lenke 1 (n = 55, age 15.28 ± 3.35) and 2 (n = 19, age 15.66 ± 3.72) curves with a complete set of PA radiographs and anterior and posterior photos. Radiographic measures for Sh.B included Cobb angles, T1 tilt, first rib angle, and clavicle-rib intersection angle. Clinical measures for Sh.B included inner shoulder angle, outer shoulder angle, and axillary fold angle. Regression analysis with Pearson's correlation and ANOVA for statistical significance was used for analysis. RESULTS: For Lenke 1 curves, there was moderate statistically significant correlation between anterior and posterior clinical Sh.B (R = 0.35-0.41). There was only weak to moderate correlation between radiographic and clinical measures. For Lenke 2 curves, there was a weak to moderate correlation between anterior and posterior clinical Sh.B (R = 0.25-0.45), though not statistically significant. There was no statistically significant correlation between any radiographic measures and posterior Sh.B. There was, however, moderate and significant correlation between radiographic measures and anterior Sh.B. CONCLUSION: There is no strong correlation between anterior and posterior clinical Sh.B, and surgeons should evaluate both sides in planning deformity correction, especially in Lenke 2 curves. None of the radiographic measures showed strong correlation (R > 0.8) with anterior or posterior clinical Sh.B. A stronger correlation existed between radiographic measures and anterior Sh.B measurements compared with posterior clinical Sh.B measurements in Lenke 2 curves further necessitating anterior evaluation in this group.

Surgical approach to the cervicothoracic junction: can a standard Smith-Robinson approach be utilized?

STUDY DESIGN: Retrospective case series study. OBJECTIVES: To determine when the standard Smith-Robinson approach can be used successfully to approach the cervicothoracic junction (CTJ). SUMMARY OF BACKGROUND DATA: Most of techniques for exposing the anterior CTJ are associated with significant morbidity. To our knowledge, there is no reliable technique, which described to determine when the standard Smith-Robinson approach is adequate and when a more invasive approach, such as a sternal splitting approach, is necessary to approach the CTJ anteriorly. METHODS: We evaluated the ability of the following technique to preoperatively determine whether a standard Smith-Robinson approach can be used to approach the CTJ: on the lateral plain radiograph, a line was drawn from the intended skin incision site to the top of the manubrium (at the suprasternal notch) to the level of the disc space. If it appeared that this trajectory would allow adequate exposure of the CTJ, then the operation was performed through the standard Smith-Robinson approach. The records and radiographs of all patients who had undergone anterior cervicothoracic arthrodesis to T1 or below were evaluated. RESULTS: A total of 99 patients who underwent an anterior cervicothoracic fusion using the standard Smith-Robinson approach were identifed. Using the proposed technique, there were no cases in which the planned lowest instrumented vertebra could not be safely reached through the standard Smith-Robinson approach. No procedure was abandoned or converted to a sternotomy approach. CONCLUSIONS: Our results suggest that if the lowest instrumented vertebra can be seen on a lateral radiograph and a line passing from the intended skin incision site to this level lies on top of the manubrium, a routine Smith-Robinson approach can be used to expose the level. To our knowledge, this is the largest series outlining a simple guideline for approaching the anterior CTJ.

Acute Cholecystitis: An Emerging Complication in Spinal Cord Injury Patients in the United States.

BACKGROUND: Spinal cord injury (SCI) is a significant medical condition associated with various secondary complications, including cholelithiasis. Cholelithiasis can cause biliary duct obstruction and result in acute cholecystitis. The development of acute cholecystitis in SCI patients has been well studied in the Taiwanese population, showing an increased risk of acute cholecystitis in patients with SCI. The development of cholecystitis has not been well studied in the United States. MATERIALS AND METHODS: A retrospective review was performed on 3,939 propensity score-matched patients aged 18 to 85 years who had SCI/surgery from 2000 to 2019. Patients were divided based on the development of postoperative complications, specifically cholecystitis with cholecystectomy. RESULTS: SCI consisted of quadriplegia (42%), paraplegia (53%), unspecified lesion of cervical spinal cord (3%), and thoracic spinal cord (2%). All groups were comparable regarding age, gender, body mass index, smoking status, and Charlson comorbidity Index. The incidence of acute cholecystitis with subsequent cholecystectomy among patients with SCI was 43.0 per 10,000 person-years (95% confidence interval: 41.51-44.49). Median follow-up was 36 months. The development of cholecystitis was comparable among females (54.5%) and males (45.5%), and among African Americans (52.5%) and Caucasians (47.5%). CONCLUSION: There is an association between SCI and development of acute cholecystitis among U.S. PATIENTS: As SCI patients do not present with the classic signs of biliary colic, risk assessment for the development of acute cholecystitis will guide patient management and allow neurosurgeons to weigh the risks and benefits of prophylactic treatment for gallbladder complications.

Crossing the Cervico-Thoracic Junction in Long Posterior Cervical Fusions Reduces Caudal Adjacent Segment Pathology.

STUDY DESIGN: Retrospective case control. OBJECTIVES: The purpose of this study is to compare clinical outcomes and rates of symptomatic caudal adjacent segment pathology (ASP) in posterior cervical fusions (PCF) constructs with end-instrumented vertebrae in the cervical spine (EIV-C) to PCF constructs that end in the proximal thoracic spine (EIV-T). METHODS: Retrospective review of 1714 consecutive cervical spinal fusion cases was done. Two groups were identified: 36 cervical end-instrumented vertebra patients (age56 ± 10 yrs) and 53 thoracic EIV patients (age 57 ± 9 yrs). Symptomatic ASP was defined as revision surgery or nerve root injection (or recommended surgery or injection) at the adjacent levels. RESULTS: EIV-C patients had a significantly higher rate of caudal-level symptomatic ASP requiring intervention compared with EIV-T patients (39% vs 15%, p = 0.01). The development of caudal-level ASP was highest at C7 (41%), followed by C6 (40%). The overall complication rate and surgical revision rates, however, were similar between the groups. Neck Disability Index outcomes at 2 years postop were significantly better in the EIV-T group (24.5 vs. 34.0, p = 0.05). CONCLUSIONS: Long PCF that cross the C-T junction have superior clinical outcomes and reduced rates of caudal breakdown, at the expense of longer fusions and higher EBL, with no increase in the rate of complications. Crossing the C-T junction affords protection of the caudal adjacent levels without adding significant operative time or morbidity.

Modic Change: An Emerging Complication in the Aging Population.

STUDY DESIGN: This was a literature review. OBJECTIVE: The objective of this study was to review the pathogenesis, prevalence, clinical associations, diagnostic modalities, and treatment options for patients with lower back pain (LBP) associated with Modic change (MC). SUMMARY OF BACKGROUND DATA: Vertebral body endplates are located between the intervertebral disk and adjacent vertebral body. Despite their crucial roles in nutrition and biomechanical stability, vertebral endplates are extremely susceptible to mechanical failure. Studies examining the events leading to disk degeneration have shown that failure often begins at the endplates. Endplate degeneration with subchondral bone marrow changes were originally noticed on magnetic resonance imaging. These magnetic resonance imaging signal changes were classified as MC. METHODS: A literature review was conducted on the history, etiology, risk factors, diagnostic modalities, and treatment of LBP with MC. RESULTS: Type 1 MC refers to the presence of increased vascularization and bone marrow edema within the vertebral body. Type 2 MC involves fatty marrow replacement within the vertebral body. Type 3 MC reflects subchondral bone sclerosis. Despite the original classification, research has supported the notion that MCs possess a transitional nature. Furthermore, type 1 MCs have been strongly associated with inflammation and severe LBP, while types 2 and 3 tend to be more stable and demonstrate less refractory pain. With a strong association to LBP, understanding the etiology of MC is crucial to optimal treatment planning. Various etiologic theories have been proposed including autoimmunity, mechanics, infection, and genetic factors. CONCLUSIONS: With the aging nature of the population, MC has emerged as an extremely prevalent issue. Research into the pathogenesis of MC is important for planning preventative and therapeutic strategies. Such strategies may include rehabilitation, surgical fixation, stabilization, steroid or cement injection, or antibiotics. Improved diagnostic methods in clinical practice are thus critical to properly identify patients suffering from MC, plan early intervention, and hasten return to functioning.