Long-term effects of local radiotherapy on growth and vertebral features in children with high-risk neuroblastoma.

BACKGROUND: To evaluate the effects of local radiotherapy (RT) on growth, we evaluated the chronological growth profiles and vertebral features of children with high-risk neuroblastoma. METHODS: Thirty-eight children who received local photon or proton beam therapy to the abdomen or retroperitoneum between January 2014 and September 2019 were included. Simple radiography of the thoracolumbar spine was performed before and every year after RT. The height and vertical length of the irradiated vertebral bodies (VBs) compared with the unirradiated VBs (vertebral body ratio, VBR) were analyzed using the linear mixed model. Shape feature analysis was performed to compare the irradiated and unirradiated vertebrae. RESULTS: The follow-up was a median of 53.5 months (range, 21-81 months) after RT. A decline in height z-scores was mainly found in the early phase after treatment. In the linear mixed model with height, the initial height (fixed, p < 0.001), sex (time interaction, p = 0.008), endocrine dysfunction (time interaction, 0.019), and age at diagnosis (fixed and time interaction, both p = 0.002) were significant. Unlike the trend in height, the change in VBR (ΔVBR) decreased gradually (p < 0.001). The ΔVBR in the group that received more than 30 Gy decreased more than in the group that received smaller doses. In the shape feature analysis, the irradiated VBs changed to a more irregular surface that were neither round nor rectangular. CONCLUSION: The irradiated VBs in children were gradually restricted compared to the unirradiated VBs in long-term follow-up, and higher RT doses were significantly affected. Radiation-induced irregular features of VBs were observed.

Vertebral body tethering for Lenke 1A curves: the lumbar modifier predicts less optimal outcomes.

INTRODUCTION: The addition of the L4 "AR" and "AL" lumbar modifier for Lenke 1A idiopathic scoliosis (IS) has been shown to direct treatment in posterior spinal fusion; however, its utility in vertebral body tethering (VBT) has yet to be evaluated. METHODS: A review of a prospective, multicenter database for VBT in IS was performed for patients with Lenke 1A deformities and a minimum of 2 years follow-up. Patients were categorized by their lumbar modifier (AR vs AL). Less optimal VBT outcome (LOVO) was defined as a final coronal curve > 35°, lumbar adding-on, or revision surgery for deformity progression or adding-on. RESULTS: Ninety-nine patients met inclusion criteria (81% female, mean 12.6 years), with 55.6% being AL curves. Overall, there were 23 instances of tether breakage (23.3%) and 20 instances of LOVO (20.2%). There was a higher rate of LOVO in AR curves (31.8% vs 10.9%, P = 0.01). Patients with LOVO had greater preoperative deformity, greater apical translation, larger coronal deformity on first erect radiographs, and less coronal deformity correction. Failure to correct the deformity < 30° on first erect was associated with LOVO, as was LIV selection short of the last touch vertebra (TV). Independent risk factors for LOVO included AR curves (OR 3.4; P = 0.04) and first erect curve magnitudes > 30 degrees (OR 6.0; P = 0.002). DISCUSSION: There is a 20.2% rate of less optimal VBT following VBT for Lenke 1A curves. AR curves are independently predictive of less optimal outcomes following VBT and require close attention to LIV selection. Surgeons should consider achieving an initial coronal correction < 30 degrees and extending the LIV to at least the TV to minimize the risk of LOVO.

Vertebral body tethering for adolescent idiopathic scoliosis: a review.

PURPOSE: Adolescent Idiopathic Scoliosis (AIS) remains the most common type of pediatric scoliosis, mostly affecting children between ages 10 and 18. Vertebral body tethering (VBT) offers a non-fusion alternative to the gold standard spinal fusion that permits flexibility and some growth within instrumented segments. This article will serve as a comprehensive literature review of the current state-of-the-art of VBT in relation to radiographic and clinical outcomes, complications, and the learning curve associated with the procedure. METHODS: A systematic literature review was conducted on PubMed, Scopus, and Web of Science from April 2002 to December 2022. Studies were included if they discussed VBT and consisted of clinical studies in which a minimum 2-years follow-up was reported, and series that included anesthetic considerations, learning curve, and early operative morbidity. RESULTS: Forty-nine studies spanning the period from April 2002 to December 2022 were reviewed. CONCLUSION: This article illustrates the potential benefits and challenges of the surgical treatment of AIS with VBT and can serve as a basis for the further study and refinement of this technique ideally as a living document that will be updated regularly.

Correlation of Bone Density Values of Quantitative Computed Tomography and Hounsfield Units Measured in Native Computed Tomography in 902 Vertebral Bodies.

OBJECTIVE: Due to the increasing age of patients, the evaluation of bone density is crucial, especially in preparation for spinal surgery. The aim of this study was to determine bone density using a computed tomography (CT) and to correlate Hounsfield units (HU) with bone density values of a quantitative computed tomography (QCT). METHODS: The study is a monocentric, retrospective data analysis. We examined 902 vertebral bodies from a total of 369 patients who received a CT of the thoracolumbar spine in the period from 2015 to 2019 and compared the HU with values of a QCT. A general equation for calculation the QCT values was established. RESULTS: We found a significant correlation between the Hounsfield units and the corresponding QCT-values (r = 0.944, P < 0.001). We also demonstrated that the calculated QCT values are independent of patient sex (P < 0.942). Furthermore, we could not demonstrate differences in the correlation of the 3 measured levels (axial, sagittal, and coronary) to the QCT values. The QCT-values can be calculated on the basis of a native CT of the lumbar spine using the equation: QCT = 17.8 + 0.7 × HU. CONCLUSIONS: The equation allows calculating bone density values without the need for an additional QCT and without further radiation exposure or costs. With this measuring method it is possible to obtain additional information from a computed tomography.

Biologic Agents Preserve the C-2 Pedicle in Patients with Rheumatoid Arthritis: A Comparative Imaging Study Using Three-Dimensional Computed Tomography.

OBJECTIVE: To investigate whether biologic agents (BAs) reduce a narrow C-2 pedicle screw trajectory, which is often a key stabilizer in surgical treatment, in patients with rheumatoid arthritis (RA). METHODS: A total of 100 patients with RA treated with and without BAs (BA [+] group [n = 50] and BA [-] group [n = 50]), respectively, were included in the present study. Computed tomography (CT) images of their cervical spine, including C-2, were analyzed. The maximum screw diameter at C-2 that could be inserted without breaching the cortex, measured on 3-dimensional images using a CT-based navigation system, was compared between the groups with and without BA administration. Furthermore, the destruction of the atlantoaxial joint was examined using CT images. The risk factors for a narrow C-2 pedicle were elucidated among the patients treated with BAs. RESULTS: The pedicle in the BA (+) group had a significantly larger C-2 maximum screw diameter than the BA (-) group (6.00 mm vs. 5.13 mm, P < 0.001), with less destruction of the atlantoaxial joint. Among the BA (+) group, a longer period until the initial administration of BAs and RA disease duration were associated with a narrow C-2 pedicle. CONCLUSIONS: This study suggests that BAs can maintain the trajectory for C-2 pedicle screws, which acts as a key stabilizer in surgical management for the rheumatoid cervical spine, by halting the destruction of the atlantoaxial joint. Early introduction of BAs can be especially important to prevent the narrowing of the C-2 pedicle.

Basivertebral foramina of true vertebrae: morphometry, topography and clinical considerations.

PURPOSE: Basivertebral foramina (BVF) are openings of the posterior wall of vertebral body (VB) that lead to basivertebral canals (BVC), where homonymous neurovascular bundle courses. BVF and BVC are implicated with spinal fractures, vertebral augmentation and basivertebral nerve radiofrequency ablation. Despite their essential clinical impact, knowledge of BVF precise anatomy is scarce. The current study describes in detail the BVF typical morphological and topographical anatomy, morphometry and variants. METHODS: In total, 1561 dried true vertebrae of 70 Greek spines of known gender and age were examined. BVF number, location, shape and size (in foramina > 1 mm), BVF distance from VB rims and pedicles, as well as VB morphometry (diameters, heights and distance between pedicles) were studied. Ten spines were re-examined by computed tomography and BVC depth and shape were recorded. Correlations and differences were statistically analyzed. RESULTS: C1 lack BVF (3.4%). One BVF was found in 45.1%, two in 36.9%, three in 3.8% and four BVF in 0.6%. Multiple small (< 1 mm) foramina were observed in 10.1%. Asymmetry was detected in 12.3%. C2 and T10-L1 presented typical pattern, whereas C3 and T2 had the greatest variability. BVF were significantly closer to the upper rim in C2 and T10-L4 and to the lower rim in C7-T4, T6-T8 and L5. The mean BVC depth was 12-21.8% of the VB anteroposterior diameter. CONCLUSION: BVF number, shape, size and topography are described, in detail, per vertebral level. The provided morphological classification and the created cumulative BVF topographic graphs should assist in clinical practice and surgery.

20 Tips to Avoid and Handle Problems in the Placement of Percutaneous Pedicle Screws.

BACKGROUND: Two-dimensional fluoroscopy-guided percutaneous pedicle screw placement is currently the most widely applied instrumentation for minimally invasive treatment of spinal injuries requiring stabilization. Although this technique has advantages over open instrumentation, it also presents new challenges and specific complications. The objective of this study was to provide recommendations developed from the experience of several spinal surgeons at different minimally invasive spine surgery reference centers to solve specific problems and prevent complications during the learning curve of this technique. METHODS: An AO Spine Latin America minimally invasive spine surgery study group analyzed the most frequent complications and challenges occurring during the placement of >14,000 two-dimensional fluoroscopy-guided percutaneous pedicle screws at different centers over 15 years. Twenty tips considered most relevant to performing this technique, excluding problems directly related to specific brands of instruments, were presented. RESULTS: The 20 tips included the following: (1) positioning; (2) clean and painless; (3) fewer x-rays; (4) check the clock; (5) beveled tip; (6) transverse-rib-pedicle; (7) double Jamshidi; (8) hammer the Kirschner wire; (9) bent tip; (10) too loose, too tight; (11) new trajectory; (12) manual control; (13) start over; (14) Kirschner wire first; (15) adhesive drape control; (16) bend the rod; (17) lower rods; (18) freehand inner; (19) posterior fusion; (20) revision. CONCLUSIONS: Implementation of these tips might improve performance of this technique and reduce the complications related to percutaneous pedicle screw placement.

Unexpected Vertebral Bodies Trapping of 99mTc-Macroaggregated Albumin During Lung Perfusion Scintigraphy in a Patient With Collateral Paravertebral Venous System.

ABSTRACT: A 35-year-old woman was referred to our nuclear medicine center for a ventilation and perfusion (VQ) pulmonary scintigraphy to detect pulmonary embolism. She was treated with low-molecular-weight heparin following a proximal venous thrombosis of the right upper limb and had a previous history of an infiltrating ductal carcinoma of the right breast. Surprisingly, the VQ scintigraphy showed uptake of 99mTc-MAA in several superior vertebrae. A contrast-enhanced CT scan revealed a dilated collateral paravertebral venous system due to the deep vein thrombosis extended from superior vena cava to brachiocephalic trunk. 99mTc-MAA was trapped through the dilated vertebral venous system.

Association of Pedicle Sign Type with Clinical and Radiological Features in Patients with Symptomatic Spinal Metastases.

BACKGROUND: Because of population aging in Japan, the number of cancer diagnoses is increasing rapidly. The pedicle sign is a valuable radiographic indicator of metastases, as the pedicle is the most commonly affected vertebral structure in radiographic assessment. However, few studies have carefully examined the morphological features of pedicle signs. To improve the capacity of medical professionals to diagnose symptomatic spinal metastases, we retrospectively examined the morphological characteristics of pedicle signs and their associations with clinical and radiological features. METHODS: 186 patients with symptomatic spinal metastases who visited our department during the period from January 1, 2011 through December 31, 2017 were enrolled. The pedicle sign was defined as a missing or obscured pedicle on an anteroposterior radiograph. Radiographs were evaluated for pedicles and other vertebrae structures. Clinical and other radiological features were compared in relation to the type of pedicle sign identified. RESULTS: Pedicle signs were classified as completely disappeared (complete, 26 patients), partially disappeared (partial, 40 patients), or obscured by the osteoblastic background (blastic, 28 patients). Disappearance of both the bone cortex and pedicle was observed in almost half of the patients with complete or partial pedicle signs. The complete pedicle sign was associated with significantly longer survival. CONCLUSION: Diagnosis of bone metastases requires understanding of pedicle sign types.

Treatment of Lumbosacral Tuberculosis with Significant Vertebral Body Loss Using Single-Stage Posterior Surgical Management with a Structural Autograft Combined with a Titanium Mesh Cage.

OBJECTIVE: Treatment of lumbosacral tuberculosis is still controversial. In our study, we assessed the efficacy and feasibility of single-stage posterior debridement, interbody fusion using a structural autograft combined with a titanium mesh cage, and posterior instrumentation for the treatment of lumbosacral tuberculosis with significant vertebral body loss. METHODS: From May 2011 to June 2018, 15 patients with lumbosacral tuberculosis with significant vertebral body loss had undergone single-stage posterior debridement, interbody fusion using a structural autograft combined with a titanium mesh cage, and posterior instrumentation. The pre- and postoperative lumbosacral angle, visual analog scale score, erythrocyte sedimentation rate, C-reactive protein, and neurological status were assessed. RESULTS: Surgery was successful for all patients, and no patient experienced tuberculosis recurrence during an average follow-up period of 27.3 months (range, 12-60 months). After surgery, the erythrocyte sedimentation rate and C-reactive protein for all patients had returned to normal within 3 months. At the final follow-up examination, the neurological status had improved in all patients who had had neurological deficits preoperatively. The mean preoperative lumbosacral angle was 12.6° (range, 6.7°-17.9°), and had increased to 27.7° (range, 24.3°-34.6°) after surgery. The average lumbosacral angle was 26.4° (range, 22.1°-32.3°), with an average loss of 1.4° (range, 0.6°-2.3°) at the final follow-up visit. CONCLUSIONS: The combination of single-stage posterior debridement, interbody fusion using structural autografts with a titanium mesh cage, and posterior instrumentation is an effective and safe option for the treatment of lumbosacral tuberculosis with significant vertebral body loss.

An aortic wall to vertebral body fistula presenting as a lytic lesion.

There have been multiple reported cases of aortic fistulas but few cases of aorta to vertebral body fistulas and no aortic wall to vertebral body fistulas have been reported. Here we present a case of a patient who is status post thoracic aortic aneurysm (TAA) repair and found to have a lytic vertebral body lesion. Biopsy of the mass revealed blood products without evidence of malignancy and further investigation revealed a fistulous tract between the aortic wall and the vertebral body causing a vertebral body hematoma.

T1-weighted Dynamic Contrast-enhanced MRI to Differentiate Nonneoplastic and Malignant Vertebral Body Lesions in the Spine.

Background Dynamic contrast agent-enhanced (DCE) perfusion MRI may help differentiate between nonneoplastic and malignant lesions in the spine. Purpose To investigate the correlation between fractional plasma volume (Vp), a parameter derived from DCE perfusion MRI, and histopathologic diagnosis for spinal lesions. Materials and Methods In this retrospective study, patients who underwent DCE perfusion MRI and lesion biopsy between May 2015 and May 2018 were included. Inclusion criteria were short time interval (<30 days) between DCE perfusion MRI and biopsy, DCE perfusion MRI performed before biopsy, and DCE perfusion MRI performed at the same spine level as biopsy. Exclusion criteria were prior radiation treatment on vertebrae of interest, poor DCE perfusion MRI quality, nondiagnostic biopsy, and extensive spinal metastasis or prior kyphoplasty. One hundred thirty-four lesions were separated into a nonneoplastic group (n = 51) and a malignant group (n = 83) on the basis of histopathologic analysis. Two investigators manually defined regions of interest in the vertebrae. DCE perfusion MRI parameter Vp was calculated by using the Tofts pharmacokinetic two-compartment model. Vp was quantified, normalized to adjacent normal vertebrae, and compared between the two groups. A Mann-Whitney U test and receiver operating characteristic analysis was performed to verify the difference in Vp between the nonneoplastic and malignant groups. Reproducibility was assessed by calculating the Cohen κ coefficient. Results One hundred patients (mean age, 65 years ± 11 [standard deviation]; 52 men) were evaluated. Vp was lower in nonneoplastic lesions versus malignant lesions (1.6 ± 1.3 vs 4.2 ± 3.0, respectively; P < .001). The sensitivity of Vp was 93% (77 of 83; 95% confidence interval [CI]: 85%, 97%), specificity was 78% (40 of 51; 95% CI: 65%, 89%), and area under the receiver operating characteristic curve was 0.88 (95% CI: 0.82, 0.95). Cohen κ coefficient suggested substantial agreement in both intra- (κ = 0.72) and interreader (κ = 0.70) reproducibility. Conclusion This study indicated that dynamic contrast agent-enhanced perfusion MRI parameter, fractional plasma volume, was able to differentiate between nonneoplastic spinal lesions and malignant lesions. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Haller in this issue.

Hounsfield units of the vertebral body and pedicle as predictors of pedicle screw loosening after degenerative lumbar spine surgery.

OBJECTIVE: The authors aimed to compare the efficacy of lumbar vertebral body Hounsfield units (HUs) and pedicle HUs at predicting pedicle screw loosening. METHODS: The authors retrospectively assessed 143 patients with L3-5 instrumentation. The patients were classified into one of two groups based on the status of their L3 screws (a screw loosening group or a control group). The pedicle HUs and vertebral HUs of L3 were measured using preoperative lumbar CT scans, and the pedicle HUs were measured in two ways: by excluding or by including cortical bone. RESULTS: The screw loosening rate was 20.3% (n = 29/143) at the 12-month follow-up. The vertebral body HUs and pedicle HUs in the screw loosening group were lower than those in the control group (vertebral body group: 98.6 HUs vs 121.4 HUs, p < 0.001; pedicle excluding cortical bone: 208.9 HUs vs 290.5 HUs, p = 0.002; pedicle including cortical bone: 249.4 HUs vs 337.5 HUs, p < 0.001). The pedicle HUs tended to have a higher area under the receiver operating characteristic curve value in predicting screw loosening, compared with that of vertebral body HUs, but the difference was not statistically significant (p > 0.05). Among patients with low vertebral body HUs of ≤ 130, the loosening rate was much lower in patients with pedicle HUs of ≤ 340 than in those with pedicle HUs of > 340 (31.0% vs 13.0%, respectively; p < 0.05). CONCLUSIONS: Vertebral body HUs alone are insufficient to accurately evaluate the risk of pedicle screw loosening. Therefore, it is important to collect both the pedicle HU and vertebral body HU measurements for surgical planning.

Thoracoscopic Vertebral Body Tethering for Adolescent Idiopathic Scoliosis: Follow-up Curve Behavior According to Sanders Skeletal Maturity Staging.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: To report the follow-up curve behaviors in different Sanders staging groups. SUMMARY OF BACKGROUND DATA: Vertebral body tethering (VBT) is a growth modulation technique that allows gradual spontaneous follow-up curve correction as the patient grows. There is a lack of scientific evidence regarding appropriate patient selection and timing of implantation. METHODS: Patients were grouped into five as: Sanders 1, 2, 3, 4-5, and 6-7. Data were collected preoperatively, at the day before discharge, and at each follow-up. Outcome measures were pulmonary and mechanical complications, readmission, and reoperation rates. Demographic, perioperative, clinical, radiographic, and complication data were compared using Fisher-Freeman-Halton exact tests for categorical variables and Kruskal-Wallis tests for the continuous variables. RESULTS: Thirty-one (29 F, 2 M) consecutive patients with a minimum of 12 months of follow-up were included. The mean age at surgery was 12.1 (10-14). The mean follow-up was 27.1 (12-62) months. The mean preoperative main thoracic curve magnitude was 47°â€Š±â€Š7.6°. For all curves, preoperative and first erect curve magnitudes, bending flexibility, and operative correction percentages were similar between groups (for all comparisons, P > 0.05). The median height gained during follow-up was different between groups (P < 0.001), which was reflected into median curve correction during follow-up. Total curve correction percentage was different between groups (P = 0.009). Four (12.9%) patients had pulmonary and six (19.4%) had mechanical complications. One (3.2%) patient required readmission and two (6.5%) required reoperation. Occurrence of pulmonary complications was similar in Sanders groups (P = 0.804), while mechanical complications and overcorrection was significantly higher in Sanders 2 patients (P = 0.002 and P = 0.018). CONCLUSION: Follow-up curve behavior after VBT is different in patients having different Sanders stages. Sanders 2 patients experienced more overcorrection, thus timing and/or correction should be adjusted, since Sanders 3, 4, and 5 patients displayed a lesser risk of mechanical complications. LEVEL OF EVIDENCE: 3.

CT validation of SVC-RA junction location for pediatric central line placement: is vertebral bodies below the carina accurate?

PURPOSE: The key landmark for tip position of a central venous catheter (CVC) is the SVC-RA junction. In adults, localization of the SVC-RA junction may be assessed as a function of vertebral body units (VBU) below the carina during CVC placement. We investigated the relationship between the SVC-RA junction and the carina in children. MATERIALS AND METHODS: 584 CT scans of 0-18 years were analyzed. The carina was marked automatically by software while the SVC-RA junction and vertebrae were marked manually. The SVC-RA junction to carina (JC) distance was the primary study measurement reported in both VBU and mm. RESULTS: The data show an average JC distance of 1.25 VBU for 0-1 year, 1.27 VBU for 1-4 years, 1.34 VBU for 4-9 years, 1.53 VBU for 9-15 years, and 1.64 VBU for 15-18 years. A positive relationship between weight and JC distance was also demonstrated. CONCLUSION: JC distance is a useful predictor of SVC-RA junction location in children. Significant relationships were shown between JC distance and both age and weight. Due to small differences between age groups, however, average JC distance for all comers (1.48 VBU, 95% CI 0.7 - 2.3) can be used for SVC-RA junction identification in CVC placement.

Accuracy and Reliability of Computer-aided Anatomical Measurements for Vertebral Body and Disc Based on Computed Tomography Scans.

OBJECTIVE: To assess whether the computed tomography (CT)-based method of three-dimensional (3D) analysis (Mimics) was accurate and reliable for spine surgical anatomical measurements. METHODS: A total of 40 lumbar segments and 32 inter-vertebral discs from eigth adult male cadavers without fractures or deformities fixed with the classical formaldehyde method were included in this research on 5 June 2017. CT scans including seven dimensions: anterior height of the vertebral body (VBHa), middle height of the vertebral body (VBHm), posterior height of the vertebral body (VBHp), width of the upper endplate (EPWu), depth of the upper endplate (EPDu), anterior height of the inter-vertebral disc in the median sagittal plane (IDHa), and posterior height of the inter-vertebral disc in the median sagittal plane (IDHp). They were performed based on uniform conditions (slice thickness: 0.625 mm) using a CT scanner on 8 June 2017. Afterwards, the surgical anatomical measurements were conducted with a Vernier caliper on 12 June 2017. The computer-aided anatomical measurements were conducted by three investigators using Mimics 16.0 to perform 3D reconstructions of CT bone on 16 June 2017. Finally, the length and angle were measured with associated measurement tools, yielding a verified accuracy of 0.01 mm and 0.01°, respectively. Each measurement was repeated three times, and all anatomical data was analyzed using the statistical software and P-value < 0.05 was considered statistically significant. RESULTS: The results showed no statistically significant difference was observed between the surgical anatomical and computer-aided anatomical measurements (P > 0.05) for lumbar vertebra measurements, and the absolute difference between surgical and computer-aided data were all less than 1.0 mm (for the VBHa, VBHm, VBHp, EPWu, and EPDu were 0.12, 0.03, 0.03, 0.31, and 0.03 mm, respectively). Moreover, although the absolute differences of discs was larger than those of lumbar vertebras, no significant differences were detected between the computer-aided and surgical anatomical measurements for the IDHa, as well as IDHp in the vast majority of measurements (P = 0.543, 0.079 or 0.052 for IDHa, and P = 0.212, 0.133 or 0.042 for IDHp). In addition, excellent reliability correlation was observed between the measurements of each investigator, and the reliability coefficients in the intra-groups were all greater than 0.9 except for IDHp (reliability coefficient = 0.892). Additionally, the reliability coefficients were greater than 0.9 for the all between-group correlations, and a significant correlation was also observed. Furthermore, no statistically significant difference for three anatomical values was found in the computer-assisted measurements of the lumbar bone structure (P > 0.05). Similarly, we did not observe a statistical difference in the anatomical data of the lumbar discs from the three measures (P > 0.05). CONCLUSIONS: Computer-aided anatomical measurement for spine based on CT scans presents the high accuracy and reliability for improving spinal surgical procedures.

Morphologic Changes of Intervertebral Foramen After Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Radiographic and Clinical Study.

OBJECTIVE: We aimed to investigate the morphologic changes in the intervertebral foramen after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), and analyze the necessity of routinely performing contralateral intervertebral foraminal decompression in degenerative lumbar spondylolisthesis cases with bilateral symptoms. METHODS: 72 single-level degenerative lumbar spndylolisthesis patients with bilateral symptoms were included, all of whom underwent unilateral approach MIS-TLIF. Preoperative and postoperative foraminal height (FH), foraminal width (FW), disc height (DH), distance from existing nerve root to upper edge of lower pedicle (RTP), and contralateral side spinal canal area (CSCA) were measured at surgical and contralateral side. Clinical outcomes were evaluated using the visual analog scale, Oswestry Disability Index, and Japanese Orthopaedic Association score. RESULTS: The preoperative values are comparable between operative and contralateral sides (P > .05). The postoperative values for FH on operative and contralateral sides were 16.23±2.48 mm and 16.10±2.42 mm, for FW were 11.36±2.58 mm and 11.31±2.71 mm, for IH were 8.18±1.58 mm and 8.42±1.54 mm, for RTP were 8.58±1.26 mm and 9.14±1.77 mm, and the CSCA of the spinal canal on the contralateral side were 211.59±48.12 mm², respectively. The difference between these was also not statistically significant (P > .05). The values increased significantly on the surgical and contralateral side (P < .05). The visual analog scale for low-back and leg pain, Japanese Orthopaedic Association, and Oswestry Disability Index improved significantly at 2-year follow-up. CONCLUSIONS: Unilateral MIS-TLIF can effectively improve contralateral FH, DH, FW, RTP, and CSCA. It is not necessary to routinely perform contralateral intervertebral foramen decompression in degenerative lumbar spondylolisthesis with bilateral symptoms when symptoms are mild on one side.

Low occupancy rate of the pedicle screw in the vertebral body leads to upper instrumented vertebral fracture.

Upper instrumented vertebra (UIV) fracture in adult spinal deformity surgery leads serious complications, such as spinal cord injury in 0.5-0.8%. Although tip-apex distance is important for preventing screw cut-out in proximal femoral fracture surgery, this suggest that the screw occupancy rate for bone fragments is also important. The purpose of this study was to investigate how the occupancy rate of pedicle screws (ORPS) affects UIV fracture. Patients with UIV fracture 1 year after surgery were defined as the fracture group (F); others were defined as the no fracture group (NF). ORPS, cut-out of pedicle screw (PS), medications, and bone mineral density were evaluated. Significant differences (P < 0.05) between group F (n = 58) and group NF (n = 260) were observed in age (71 years old in group F and 65 years old in group NF), diabetes medication use (19% in group F and 4% in group NF), steroid drug use (10% in group F and 2% in group NF), and ORPS (70% in group F and 76% in group NF). The cut-off value of ORPS using receiver operator characteristic analysis was 73%. Multiple logistic regression analysis identified diabetes medication use (P = 0.026, odds ratio [OR] 4.0) and ORPS < 73% (P = 0.001, OR 3.6) as significant risk factors for UIV fracture. The surgeon can't control use of diabetes medication. However, they can replace with longer PS when ORPS < 73% is detected on radiographs taken during surgery. Further studies will be needed to better elucidate it's use.

Bertolotti syndrome: a not-to-miss cause of chronic low back pain in young adults.

Low back pain (LBP) in young adults is a common condition that needs to be appropriately examined in cases of refractory to classic treatment strategies. We present two cases of chronic LBP with challenging diagnosis and treatment refractoriness. The first case corresponds to a young lady that has been treated mistakenly with an anti-tumor necrosis factor because her treating doctors diagnosed unilateral sacroiliitis which turned out to be a magnetic resonance imaging (MRI) artifact (partial volume artifact). The second case is about another young lady with chronic LBP that did not respond to the classic treatment with non-steroidal anti-inflammatory drugs. Both cases have been diagnosed as having Bertolotti syndrome. Bertolotti syndrome is an anatomical abnormality consisting of partial unilateral or bilateral fusion of the transverse process of the lowest lumbar vertebrae to the sacrum. The presentation of both cases highlights the importance of a minute history taking and clinical examination especially in young patients with chronic LBP.