Novel AI-Based Algorithm for the Automated Measurement of Cervical Sagittal Balance Parameters. A Validation Study on Pre- and Postoperative Radiographs of 129 Patients.

STUDY DESIGN: Retrospective, mono-centric cohort research study. OBJECTIVES: The analysis of cervical sagittal balance parameters is essential for preoperative planning and dependent on the physician's experience. A fully automated artificial intelligence-based algorithm could contribute to an objective analysis and save time. Therefore, this algorithm should be validated in this study. METHODS: Two surgeons measured C2-C7 lordosis, C1-C7 Sagittal Vertical Axis (SVA), C2-C7-SVA, C7-slope and T1-slope in pre- and postoperative lateral cervical X-rays of 129 patients undergoing anterior cervical surgery. All parameters were measured twice by surgeons and compared to the measurements by the AI algorithm consisting of 4 deep convolutional neural networks. Agreement between raters was quantified, among other metrics, by mean errors and single measure intraclass correlation coefficients for absolute agreement. RESULTS: ICC-values for intra- (range: .92-1.0) and inter-rater (.91-1.0) reliability reflect excellent agreement between human raters. The AI-algorithm could determine all parameters with excellent ICC-values (preop:0.80-1.0; postop:0.86-.99). For a comparison between the AI algorithm and 1 surgeon, mean errors were smallest for C1-C7 SVA (preop: -.3 mm (95% CI:-.6 to -.1 mm), post: .3 mm (.0-.7 mm)) and largest for C2-C7 lordosis (preop:-2.2° (-2.9 to -1.6°), postop: 2.3°(-3.0 to -1.7°)). The automatic measurement was possible in 99% and 98% of pre- and postoperative images for all parameters except T1 slope, which had a detection rate of 48% and 51% in pre- and postoperative images. CONCLUSION: This study validates that an AI-algorithm can reliably measure cervical sagittal balance parameters automatically in patients suffering from degenerative spinal diseases. It may simplify manual measurements and autonomously analyze large-scale datasets. Further studies are required to validate the algorithm on a larger and more diverse patient cohort.

How Does Anxiety and Depression Affect the Outcome after Periradicular Infiltration Therapy?-A Retrospective Analysis of Patients Undergoing CT-Guided Single-Level Nerve Root Infiltration Due to Chronic Monoradicular Pain.

The aim of this study was to research the influence of psychological confounders on patient-reported outcomes (PROs) after lumbar infiltration therapies of periradicular infiltrations (PRI). Patients who underwent PRI in a single center between June 2018 and December 2019 were included. PRI was performed in patients with predominantly unilateral lumbar radiculopathy which existed for at least 6 weeks based on single-level nerve root compression (caused by a herniated disc, stenosis of the lateral recess, or neuroforamen), confirmed by morphological imaging. The numeric pain rating scale (NRS) for back pain (BP) and leg pain (LP) and the Oswestry Disability Index (ODI) were assessed preinterventionally, on the first day (only NRS) and at 6 weeks, and then 3, 6, and 12 months postinterventionally. The minimally clinically important difference (MCID) served as the threshold for the therapeutic effectiveness evaluation. The health-related quality of life (SF-36) was recorded preinterventionally and after 12 months. Based on the Hospital Anxiety and Depression Scale, the patients were dichotomized into depressed or nondepressed and anxious or nonanxious. Categorical data were evaluated using Fisher's exact test, and continuous data were evaluated using Student's t test. Separate linear mixed models were built to estimate the effect of anxiety or depression on repeatedly measured PROs following PRI. Data were analyzed using SPSS software. The analysis included 102 patients. Most mean baseline PROs were significantly worse in anxious or depressed patients than in nonanxious or nondepressed patients: Anxiety NRS-BP (p = 0.007), ODI (p < 0.001); Depression NRS-BP (p = 0.026), NRS-LP (p < 0.001), ODI (p < 0.001). All patients showed a clinically meaningful reduction in pain and functional improvement over a 12-month follow-up. There was no significant difference in the estimated overall mean PRO between all patients (p > 0.05). In conclusion, anxiety and depression are associated with worse PROs before and after PRI. However, patients with underlying depression or anxiety can expect a similar gain in PRO compared to patients without depressive or anxious symptoms.

Next Level in Computed Tomography-Guided Periradicular Infiltration Therapy: Same Efficiency with Less Radiation Exposure.

OBJECTIVE: This retrospective cohort study investigated the radiation exposure and clinical efficiency of a new institutional low-dose protocol for computed tomography (CT)-guided lumbar periradicular infiltration (PRI). METHODS: This was a retrospective matched-pair comparison of patients undergoing single-level lumbar PRI therapy employing a new low-dose CT protocol consisting of a helical scan with reduced energy levels and tube current versus the institutional standard CT protocol. The following variables were collected: dose-length product for the planning step, interventional step, and total examination, number of CT guidance scans, examination time, and postprocedural improvement on the numerical rating scale for radicular pain. RESULTS: Forty-five patients were allocated to each group. A sufficient radiation dose reduction of 30% during PRI was achieved with the low-dose protocol with a median dose-length product of 9.8 mGy∗cm compared to 32.9 mGy∗cm with the standard protocol (P < 0.001). No need for additional multiple scans during the interventional mode was observed in the low-dose group, resulting in a comparable procedure time between the groups. Furthermore, the short-term pain-reducing effect of PRI was comparable between the low-dose and standard protocols (median delta numerical rating scale = 4 in both groups). CONCLUSIONS: Our low-dose protocol with less tube voltage and lower electric current leads to less radiation exposure with the same safety and efficiency. In conclusion, every facility that performs CT-based procedures should check whether a further dose reduction is applicable to avoid stochastic radiation damage to the patient.

Local Infiltrations in Patients with Radiculopathy or Chronic Low Back Pain Due to Segment Degeneration-Only A Diagnostic Value?

The purpose of this study was to investigate the differences in the therapeutic effectiveness of CT-assisted infiltration of a local anesthetic + corticosteroid between nerve root and facet joint capsule in patients with chronic complaints. In this prospective trial with a 12-month follow-up, a total of 250 patients with chronic low back pain and radiculopathy were assigned to two groups. In the first group, patients with specific lumbar pain due to spondyloarthritis received periarticular facet joint capsule infiltration (FJI). In the second group, patients with monoradicular pain received periradicular infiltration (PRI) via an extraforaminal selective nerve block. Clinical improvement after FJI and PRI regarding pain (NRS), function (ODI), satisfaction (McNab), and health related quality of life (SF-36) were compared. Minimally clinically important difference (MCID) served as the threshold for therapeutic effectiveness evaluation. A total of 196 patients were available for final analysis. With respect to the pain reduction and functional improvement (ODI, NRSoverall, and NRSback), the PRI group performed significantly better (ptreatment < 0.001) and longer over time (ptreatment × time 0.001) than the FJI group. Regarding pain and function, only PRI demonstrated a durable improvement larger than MCID. A significant and durable therapeutic value was found only after receiving PRI but not after FJI in patients with chronic pain.

Cone-Beam Navigation Can Reduce the Radiation Exposure and Save Fusion Length-Dependent Operation Time in Comparison to Conventional Fluoroscopy in Pedicle-Screw-Based Lumbar Interbody Fusion.

This study investigates the advantages and disadvantages of cone-beam-based navigated standardized posterior lumbar interbody fusion surgery (PLIF), regarding the radiation exposure and perioperative time management, compared to the use of fluoroscopy. Patients treated receiving an elective one- to three-level PLIF were retrospectively enrolled in the study. The surgery time, preparation time, operation room time, and effective dose (mSv) were analyzed for comparison of the radiation exposure and time consumption between cone-beam and fluoroscopy; Results: 214 patients were included (108 cone-beam navigated, and 106 traditional fluoroscopies). Using cone-beam navigation, reductions in the effective dose (2.23 ± 1.96 mSv vs. 3.39 ± 2.32 mSv, p = 0.002) and mean surgery time of 30 min (143.62 ± 43.87 min vs. 171.10 ± 48.91 min, p < 0.001) were demonstrated, which leveled out the extended preparation time of 7−8 min (37.25 ± 9.99 min vs. 29.65 ± 7.69 min, p < 0.001). These effects were fusion length dependent and demonstrated additional benefits in multisegmental surgeries. The cone-beam navigation system led to a reduction in the perioperative time requirements and radiation exposure. Furthermore, the controversially discussed longer preparation time when using cone-beam navigation was amortized by a shortened surgery time, especially in multilevel surgery.

Does Total Hip Arthroplasty Influence the Development and Localization of Sacral Insufficiency Fractures?

BACKGROUND: Sacral insufficiency fractures (SIFs) are fractures related to reduced bone strength. In a previous study, we noticed that many patients with SIF had undergone total hip arthroplasty (THA). Therefore, the purpose of the present study was to research the localization of clinically apparent SIFs in relation to unilateral THA as well as the influence of unilateral THA on bone mineral density changes in the sacrum. METHODS: In this retrospective study, 171 patients with SIFs were screened for unilateral THA. In the group of patients with SIF and THA, the rate of SIF ipsilateral and contralateral to the side of the THA was determined. In a second cohort of 39 THA patients with healthy bone, changes in bone mineral density at the sacral alae ipsilateral and contralateral to the THA were analyzed by use of computed tomography immediately postoperatively and at the 1-year follow-up. RESULTS: Of the 171 patients with SIF, 50 (40 female; mean age, 79 years; range, 54 to 101 years) were previously treated with THA. Of the 50, 31 patients were treated with unilateral THA. The proportion of patients with an SIF contralateral to the THA was 42% (13 of 31) and ipsilateral to the THA was 19% (6 of 31). Twelve patients had bilateral SIFs. The mean age of the THA group without SIF was 62 years (range, 49 to 79 years); 17 were female. The median bone mineral density decreased significantly (p = 0.023), from 35.0 to 13.0 HU, at the sacral ala contralateral to the THA, whereas the decrease of ipsilateral bone mineral density, from 24.0 to 17.0 HU, was not significant (p = 0.361). CONCLUSIONS: The proportion of patients with an SIF contralateral to a THA was twice as high as that of patients with an SIF ipsilateral to a THA. These findings are supported by the second cohort's decrease in bone mineral density at the sacral ala contralateral to the THA at 1 year after surgery. We conclude that THA can lead to spatially different remodeling of the sacrum, possibly affecting the development of SIFs. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Significance of Lumbar MRI in Diagnosis of Sacral Insufficiency Fracture.

STUDY DESIGN: Retrospective observational study. OBJECTIVE: The aim of the present study was to evaluate the role of lumbar magnetic resonance imaging (MRI) in the diagnostic algorithm of sacral insufficiency fractures (SIF). The primary objective was to compare the sensitivity in fracture detection and correct fracture classification according to MRI and computed tomography (CT). The secondary objective was to identify differences of additional pathologies found in MRI of the lumbar spine and the pelvis and their rates. METHODS: A total of 943 patients (from 2010 to 2017) with fracture of the pelvic ring were screened. All patients without high-energy trauma and radiologic diagnostics consisting of X-ray, CT, and MRI of the pelvis or the lumbar spine including the sacrum were included. Differences in fracture detection and description in the various radiologic procedures were evaluated. Detection rates of additional pathologies in MRI of the pelvis and lumbar spine were recorded. RESULTS: A total of 77 subjects were included. The sensitivities for SIF were 14% in X-ray and 88% in CT, and all fractures were detected in MRI. MRI showed a more complex fracture pattern compared with CT in 65% of the cases. Additional pathologies were seen in MRI of the lumbar spine (51%) and that of the pelvis (18%). CONCLUSIONS: We suggest performing MRI of the lumbar spine including the sacrum with coronal STIR (short tau inversion recovery) sequence for elderly patients with suddenly increasing low back pain at an early stage. This procedure might improve fracture detection, classification, and recognition of concomitant pathologies.

Influence of Anxiety and Depression, Self-Rated Return-to-Work Problems, and Unemployment on the Outcome of Outpatient Rehabilitation After Shoulder Arthroscopy.

OBJECTIVE: The aim of this study was to research the influence of psychosocial confounders on outpatient rehabilitation after arthroscopic shoulder surgery. DESIGN: This retrospective study included patients who underwent such rehabilitation in a single center between January 2014 and October 2016. Shoulder function (Constant Shoulder Score) and pain (visual analog scale), improvements in these scores, and patient satisfaction were evaluated with regard to anxiety and depression (Hospital Anxiety and Depression Scale), self-rated return-to-work problems (Würzburg screening), and employment status. RESULTS: The analysis included 176 patients. The mean (SD) Constant Shoulder Score and visual analog scale improved from 53.9 (18) to 75.4 (16.5) and 4.6 (2.1) to 2.9 (2.4) cm, respectively. A total of 84.1% of the patients were satisfied with the outcome. Unemployed patients (P = 0.001) and Hospital Anxiety and Depression Scale-positive ones (P = 0.014) were less satisfied than their counterparts. Patients with a Würzburg screening-positive screening showed less improvement in pain (P = 0.015), function (P = 0.016), and satisfaction (P = 0.002) than those without. Unemployed reported more pain (P = 0.008) than employed patients when starting rehabilitation. At the end of rehabilitation, all psychosocial scores (Hospital Anxiety and Depression Scale, P = 0.002; Würzburg screening, P = 0.001; unemployment, P < 0.001) negatively influenced pain, Würzburg screening (P = 0.007), and unemployment (P = 0.008) function. CONCLUSIONS: Because we identified psychosocial factors that influence the success of outpatient shoulder rehabilitation, rehabilitation setup should be adjusted in patients with such problems.

Elongated Conus Medullaris, Sacral Agenesis, and Scoliosis: A Case Report of a Patient with Trisomy 19q and Monosomy 7q.

BACKGROUND: Progression of scoliosis following completion of growth, and the combination of low mental retardation and the conspicuous sagittal clinical and radiographic abnormalities suggest a secondary genesis of the scoliosis according to a genetic aberration. CASE DESCRIPTION: In the outpatient department, an 18-year-old woman presents with scoliosis and mild mental retardation. Radiography findings demonstrate a sacral agenesis and then consecutively performed magnetic resonance imaging on a conus depression. Because of the symptom constellation, a genetic syndrome was suspected. Genetic diagnostics revealed a trisomy 19q and monosomy 7q. Typically, deletions of the subtelomere 7q show a phenotype with growth retardation, facial anomalies, and intellectual deficit; trisomy of the subtelomere 19q shows growth retardation, atypical ears, short neck, and intellectual deficit with delayed development. The further clinical radiologic and neurologic examination showed no evidence of a tethered cord syndrome. The correction of scoliosis was performed under intraoperative neurophysiological monitoring without neurologic complications. CONCLUSIONS: In the presence of dysplastic sacral changes and accompanying elongated conus medullaris in patients with scoliosis, it is always necessary to think of rare chromosome aberrations and to initiate appropriate diagnostics before surgery. The intraoperative neurophysiological monitoring is strongly recommended, owing to a morphologically, and not fully-excludable, tethered cord syndrome.

[Safety and efficacy of an electron beam melting technique-manufactured titanium mesh cage for lumbar interbody fusion]. / Sicherheit und Effektivität eines in Electron-Beam-Melting-Technik hergestellten Titan-Mesh-Cages zur intersomatischen lumbalen Fusion.

BACKGROUND: Electron beam melting (EBM) technique enables cage design changes such as the integration of guide rails on the cage surface or a 3D matrix for osseointegration. A change in manufacturing technique or design can lead to a decreased fusion rate or impaired applicability. OBJECTIVE: The aim of the present study was to evaluate cage handling, lordosis reconstruction capability, and fusion rate 1 year after surgery. MATERIALS AND METHODS: In this study, 50 patients who had undergone minimally invasive transforaminal lumbar interbody fusion (TLIF) or open posterior lumbar interbody fusion (PLIF) using an EBM-manufactured cage were retrospectively included. Fusion evaluation was based on routinely performed CTs and flexion-extension radiographs 12 months postoperatively. Lumbar and segmental lordosis were compared between pre-, post, and 1­year follow-up. Postoperative cage position was used for evaluation of cage handling. RESULTS: The radiological fusion rate was 97% at the 1­year follow-up. Two cages were placed into the endplates during surgery without an effect on fusion. In 31% of the cages, placement at the anterior third of the disk space was possible. Lumbar lordosis was improved by a mean of 5° and segmental lordosis by a mean of 4°. At final follow-up, 1° was lost in both parameters. No implant-associated complications were registered. CONCLUSION: The implant is safe and leads to a very high fusion rate. A learning curve results from the fact that the cage follows a defined radius dictated by the guide rails. Addressing this, exact placement at the anterior endplate can be achieved.

Effect of propranolol on cardiac cytokine expression after myocardial infarction in rats.

The pro-inflammatory cytokines interleukin (IL)-1beta and IL-6 have been shown to be upregulated in the myocardium after injury and after adrenergic receptor stimulation. Together with other cytokines, such as the transforming growth factor (TGF)-beta, the pro-inflammatory cytokines have been implicated in the initiation of tissue repair and wound healing after myocardial infarction (MI). In the present study, the effect of beta-adrenergic receptor blockade with propranolol (2 mg/kg x h s.c. by miniosmotic pumps) on cardiac cytokine expression and on wound healing was analyzed in rats from 6-72 h after MI. IL-1beta and IL-6 gene expression strongly increased in the infarcted myocardium 6 h after MI and peaked after 12 h, while TGF-beta, progressively increased from 12 h onwards. Also, TGF-beta2 increased after 12 h, peaked after 24 h and declined thereafter, while TGF-beta, was only elevated after 72 h. Treatment with propranolol had a negative chronotropic effect throughout the observation period of 72 h. It attenuated the initial elevation in LVEDP and increased cardiac output ultimately. Furthermore, propranolol attenuated IL-1beta mRNA expression, but had not effect on the other cytokines. Moreover, MMP-9 gelatinolytic activity was markedly attenuated by propranolol indicating a delayed resorption of the necrotic tissue and, possibly, collagen turnover. Replacement by scar tissue, however, was not affected as indicated by normal collagen expression.

Significance of matrix metalloproteinases in norepinephrine-induced remodelling of rat hearts.

OBJECTIVE: Norepinephrine (NE) induced hypertrophy and remodelling of the extracellular matrix (ECM) in the left ventricle (LV) of the rat heart with resulting fibrosis. However, there was no increased collagen deposition in the right ventricle (RV). To test the hypothesis that lack of RV fibrosis is the result of elevated cleavage of collagens we inhibited the activity of matrix metalloproteinases (MMP) by doxycycline (Doxy) and then measured function and collagen metabolism in the RV as compared to the LV. METHODS: Female Sprague-Dawley rats were treated with 30 mg/kg per day doxycycline alone or in combination with i.v. infusion of NE (0.1 mg/kg per h). The activity of MMP-2 was increased both in the LV and RV after 3 days of NE infusion and reduced after concomitant doxycycline treatment which also caused inhibition when given alone. RESULTS: After 14 days of NE infusion in combination with doxycycline there was an additional increase in the NE-induced elevation of collagen accumulation in the LV (interstitial collagen fraction: NE-Doxy 1.797%, P<0.05 versus control and NE; NE 1.113%, P<0.05 versus control) and significant fibrosis in the RV (2.105%, P<0.05 versus control). This correlated with the prevention of the NE-induced elevation of RV systolic pressure (NE: 71.3 mmHg, P<0.05; NE-Doxy: 36.4 mmHg) and RV dP/dt(max) (NE: 5500 mmHg/s, P<0.05; NE-Doxy: 2550 mmHg/s). Also in the NE-stimulated LV, the doxycycline-induced collagen accumulation was associated with reduced LV dP/dt(max) (NE-Doxy: 13169 mmHg/s; NE: 18849 mmHg/s, P<0.05). CONCLUSION: MMP inhibition leads to myocardial stiffness with negative functional consequences for the RV and LV in NE-treated rat hearts.