Navigation versus fluoroscopy in minimalinvasive iliosacral screw placement.

INTRODUCTION: When needed operative treatment of sacral fractures is mostly performed with percutaneous iliosacral screw fixation. The advantage of navigation in insertion of pedicle screws already could be shown by former investigations. The aim of this investigation was now to analyze which influence iliosacral screw placement guided by navigation has on duration of surgery, radiation exposure and accuracy of screw placement compared to the technique guided by fluoroscopy. METHODS: 68 Consecutive patients with sacral fractures who have been treated by iliosacral screws were inclouded. Overall, 85 screws have been implanted in these patients. Beside of demographic data the duration of surgery, duration of radiation, dose of radiation and accuracy of screw placement were analyzed. RESULTS: When iliosacral screw placement was guided by navigation instead of fluoroscopy the dose of radiation per inserted screw (155.0 cGy*cm2 vs. 469.4 cGy*cm2 p < 0.0001) as well as the duration of radiation use (84.8 s vs. 147.5 s p < 0.0001) were significantly lower. The use of navigation lead to a significant reduction of duration of surgery (39.0 min vs. 60.1 min p < 0.01). The placement of the screws showed a significantly higher accuracy when performed by navigation (0 misplaced screws vs 6 misplaced screws-p < 0.0001). CONCLUSION: Based on these results minimal invasive iliosacral screw placement guided by navigation seems to be a safe procedure, which leads to a reduced exposure to radiation for the patient and the surgeon, a reduced duration of surgery as well as a higher accuracy of screw placement.

Outcome of Targeted vs Empiric Antibiotic Therapy in the Treatment of Spondylodiscitis: A Retrospective Analysis of 201 Patients.

BACKGROUND: Antibiotic treatment of spondylodiscitis is influenced by antibiotic stewardship; specifically, empirical antibiotic therapy is avoided in favor of-delayed-targeted antibiotic therapy after microbiological diagnosis. Only patients with neurological deficits or clinical signs of sepsis should be treated by empirical antibiotic therapy. However, the level of evidence for this treatment concept is weak. PURPOSE: The aim of this study was to investigate whether patients who were treated with a nontargeted antibiotic therapy show a worse outcome than patients who were exclusively treated with targeted antibiotic therapy. STUDY DESIGN/SETTING: A retrospective single-center data analysis. PATIENT SAMPLE: We included 201 patients with spondylodiscitis who were treated at the authors' institution between 2013 and 2020. OUTCOME MEASURES: Mortality rate, time in hospital, development of laboratory parameters, and development of pain (visual analog scale). METHODS: We performed a retrospective data analysis of patients who were treated for spondylodiscitis from January 2013 to March 2020. Clinical and demographic data as well as outcome and complications were recorded and analyzed. We investigated whether patients who were treated by a nontargeted antibiotic therapy had a worse outcome than patients who were exclusively treated by targeted antibiotic therapy and which other clinical factors had an impact on clinical outcome. RESULTS: A total of 201 patients were included, 37 of whom developed sepsis during their hospital stay, and 14 of these 37 patients died. The 14 patients who died represented (10.0%) of the subgroup who received an empirical antibiotic treatment before the targeted antibiotic therapy (n = 141). There were 0 deaths in the subgroup who did not receive an empirical antibiotic treatment (P < 0.05). The time to diagnosis since admission to the hospital was 10.5 (2.2) days in patients with sepsis; in patients without sepsis, it was 5.2 (0.9) days (P < 0.05). CONCLUSIONS: Based on the results of this investigation, the authors recommend delaying antibiotic therapy until targeted antibiotic therapy is possible. Furthermore, early diagnosis of spondylodiscitis and prevention and early detection of sepsis are essential to reduce the mortality rate of patients with spondylodiscitis.

May bending radiographs be replaced by magnetic resonance imaging in patients with adolescent idiopathic scoliosis?

PURPOSE: There is no data that shows if it is possible to determine if a curve is structural or non-structural or to assess flexibility of an adolescent idiopathic scoliosis (AIS) by magnetic resonance imaging (MRI) instead of bending radiographs (BR). We investigated if the results of BR may be compared to those of MRI. METHODS: We retrospectively analyzed prospectively collected data of patients with AIS in whom a selective spinal fusion was performed and in whom a MRI, BR and full-spine X-rays were obtained preoperatively. We measured the Cobb angles of the main and of the minor curve in full-spine X-ray (FSR), BR and MRI and analyzed the degree of the intervertebral disk degeneration in the MRI. RESULTS: After applying inclusion and exclusion criteria, 25 patients were included. We found a significant correlation (p < 0.05, Corr Coeff = 0.41) between the Cobb angle of the main curve in FSR and the Cobb angle of the main curve in the MRI and between the Cobb angle of the minor curve in FSR and the Cobb angle of the minor curve in the MRI (p < 0.001, Corr Coeff = 0.04). All patients with a minor curve of less than 25° in the BR had a Cobb angle of less than 30° in the MRI. CONCLUSION: Spinal curves showed a significant correlation between bending radiographs and recumbent images (MRI). In our group of patients, a Cobb angle of the minor curve of less than 30° in the MRI indicated that this minor curve was non-structural according to the classification of Lenke.

Surgical Site Infection After Posterior Stabilization of the Spine - When do we Have to Remove the Implants?

STUDY DESIGN: Retrospective data analysis. OBJECTION: The primary objective of this investigation was to analyze if treatment of Postoperative surgical site infections (PSSI) after posterior stabilization of the spine (PS) without radiological signs of screw loosening (RSL) shows a sufficient success rate without implant removal and if there was any difference between early and late PSSI. SUMMARY OF BACKGROUND DATA: PSSI after PS are usually treated by implant removal and reinstrumentation if loosening of one of more screws is detected. There is presently no conclusive data that shows the success rate of the treatment of PSSI after PS without implant removal if no RSL are perceived. MATERIALS AND METHODS: All patients who were treated for a PSSI after PS without RSL in a single spine center from 12/2009 to 03/2020 were enrolled in a retrospective analysis. Patients were treated by revision surgery with debridement and irrigation and subsequent antibiotic therapy. Implant removal was performed if the initial treatment did not lead to an improvement in wound healing and normalization of laboratory values. Statistical analysis was performed by Statistical Package for the Social Sciences 25. Descriptive data are given as mean and standard error of mean, a χ 2 test was performed. RESULTS: Of the 32 enrolled patients, 17 had an early PSSI, 15 a late PSSI. In 71.9% (23/32), the PSSI was treated without implant removal: 12/17 in early PSSI, 11/15 in late PSSI. The difference was not significant ( P >0.05). One patient died, all other patients were discharged from the hospital with no remaining laboratory signs of the infection and with closed soft tissues. CONCLUSIONS: In our group of patients, the success rate of irrigation and debridement without implant removal was 71.9%. In the light of this data, performing at least two irrigations and debridement before implant removal seems to be a valid treatment option in PSSI after PS if there are no RSL in early and late PSSI.

Bovine-derived xenograft is a viable bone graft substitute in multilevel, instrumented, spinal fusion.

Objective: To evaluate radiological outcomes following the use of xenogeneic bone graft substitute (BGS) in patients undergoing multisegmental spinal fusion. Summery of Background Data: Data exists for single level and short segment fusions, there presently is a paucity of data on fusion rate after bone augmentation with BGS in multisegmental posterior spinal fusion (PSF). The leading concern is pseudarthrosis, which often leads to a loss of correction after PSF. Therefore, the bone graft is an essential aspect of PSF. Methods: We retrospectively analysed the radiological data of a consecutive cohort of patients who had been treated for adolescent idiopathic scoliosis (AIS) via multisegmental spinal fusion, in whom a bovine derived BGS had been used and had a complete dataset of 24 months follow-up. The Cobb angle of the main curve was measured pre-operatively and then at 6, 12 and 24 months post-operatively. Loosening of the screws was recorded at the same post-operative time points. Results: After applying inclusion and exclusion criteria, 28 patients were included. We found no significant change of the cobb angle from the main curve as well as the cobb angle from the thoracic kyphosis during the 24 months of follow up. No patient showed a lack of bony fusion. There was 1 revision surgery, which was due to trauma. Conclusion: In this cohort, all patients showed successful bone fusion during a 24-month follow-up. Additionally, there was no change in the Cobb angle during the 2-year post-operative period. Our data indicates that the use of bovine-derived BGS supports bone fusion after multisegmental posterior instrumented fusion of the spine.

May bending radiographs be replaced by recumbent CT scans in patients with adolescent idiopathic scoliosis?

PURPOSE: There is no data that show if it is possible to determine if a curve is structural or non-structural or to assess flexibility of an adolescent idiopathic scoliosis (AIS) by recumbent images like a CT scan (CTS) instead of bending radiographs (BR). We investigated if the results of BR may be compared to those of CTS. METHODS: We retrospectively analyzed prospectively collected data of patients with AIS in whom a selective spinal fusion was performed and in whom a CTS, BR, and full spine x-rays were made preoperatively. We measured the Cobb angles of the main and the minor curve in full spine x-ray, BR, and CTS. RESULTS: After applying inclusion and exclusion criteria, 39 patients were included. We found a strong correlation (r = 0.806, p < 0.01) between the Cobb angle of the main curve in BR and the Cobb angle of the main curve in the CTS and between the Cobb angle of the minor curve in BR and the Cobb angle of the minor curve in the CTS (r = 0.601, p < 0.01). All patients with a minor curve of less than 25 degrees in the BR had a Cobb angle of less than 35 degrees in the CTS. CONCLUSION: Spinal curves showed a significant correlation between bending radiographs and recumbent images (CTS). In our group of patients, a Cobb angle of the minor curve of less than 35 degrees in the CTS indicated that this minor curve was non-structural.

Effective dose of radiation per screw in surgery of adolescent idiopathic scoliosis: matched pair analysis of 293 pedicle screws inserted using three different techniques.

PURPOSE: Reports on heterogenous groups of patients have indicated that pedicle screw insertion guided by navigation (PIN) leads to, for the patient, higher doses of radiation compared with pedicle screw insertion guided by fluoroscopy (PIF). This would be a major concern, especially in paediatric deformity correction. METHODS: After a power analysis (aiming at > 0.8) 293 pedicle screws which were inserted in patients with adolescent idiopathic scoliosis were analyzed by comparing effective dose and fluoroscopy time per screw for three different techniques. Groups 2 and 3 were matched to Group 1 by Lenke type of scoliosis. Group 1 were prospectively enrolled consecutive patients that have been operated on by PIN with image acquisition by preoperative CT scan (CTS). Group 2 were consecutive retrospectively matched patients who have been operated on by PIN with image acquisition by an intraoperative 3D scan (3DS). Group 3 were consecutive retrospectively matched patients who have been operated on by PIF. RESULTS: Mean dose of radiation per screw was 1.0 mSv (sd 0.8) per screw in CTS patients, 0.025 mSv (sd 0.001) per screw in 3DS patients and 0.781 mSv (sd 0.12) per screw in PIF patients. The difference was significant (p < 0.0001). CONCLUSION: When we compared different techniques of navigation, navigation by image acquisition with CTS showed a significantly higher (by 97.5%) dose of radiation per screw for the patient than navigation by image acquisition by a 3DS. Navigation by 3DS showed significantly lower effective dose per screw for the adolescent patients than the fluoroscopic technique. LEVEL OF EVIDENCE: II.

MRI based analysis of grade of spinal canal stenosis and grade of compression of nerve root by lumbar disc herniation as tools to predict probability to need surgical treatment.

BACKGROUND: Patients with a lumbar disc herniation (LDH) without high-grade neurological deficit (PWN) are usually treated non-operatively. If non-operative treatment is not successful, a postponed surgical treatment is performed. Postponed surgery is reported to show later improvement of pain and health-related quality of life and later return to work than early surgery. There are presently no objective parameters to predict if non-operative treatment may be successful in PWN, or if an early surgical treatment could be performed. METHODS: To analyze if high-grade spinal canal stenosis lead to a higher rate of surgical treatment in PWN, we conducted a retrospective single-center cohort study and included PWN with acute onset of severe radicular pain (VAS ≥8). We excluded patients with workers' compensation involvement, chronic pain syndrome, motor deficit <3/5, malignancy and history of prior spinal surgery. All patients were initially treated by the same standardized non-operative treatment. It was monitored if patients eventually choose an operative treatment or not. After a power analysis (aiming at >0.8), 1,053 consecutive patients (02.2008 to 12.2017) were identified by diagnostic code. One hundred and eight patients were enrolled in our investigation. Thirty-nine patients were treated non-operatively (Group 1), 69 were treated by operation (Group 2). RESULTS: Percent (%) spinal canal compromise based on cross-sectional area of LDH was 26.3% in Group 1, 33.7% in Group 2. The difference was significant (P<0.025). CONCLUSIONS: The investigated group of PWN had a significantly higher probability to need surgical treatment if they had a high-grade stenosis of the spinal canal. However, these results do not constitute a general indication for surgical treatment of PWN. The results of this study merely provide information for patients, and spine specialists, to be implemented in an individual decision-process that leads to a recommendation for type of treatment.

Lumbar lordosis as tool to assess the level of pain in patients with low back pain after lumbar disc herniation.

BACKGROUND: It is presently unknown if lumbar lordosis (LL) might be applied to monitor low back pain (LBP) in patients with lumbar disc herniation (LDH). There is presently only conflicting data that does not show a correlation of LL with LBP: Previous studies do either include chronic LBP or do not consider that each patient has an individual value of LL that cannot be compared to other patients. METHODS: Power analysis: At least 32 patients had to be enrolled in the study. Out of 84 consecutive patients with acute onset of pain (<6 weeks) that were treated operatively from 11/2015 to 04/2017 by microscopic laminotomy for LDH, 35 were enrolled in this retrospective within - subject analysis after exclusion of patients with chronic LBP or severe disc degeneration of the lumbar spine. We recorded self - reported assessment of pain (VAS) and LL before the operation, 1 week and 6 weeks after the operation. We performed a paired - samples t - test (within - subject) to compare means of LL at admission to our institution with LL 6 weeks after surgery. Pearson's correlation was determined for LL and VAS. Significance level was set at p < 0.05. RESULTS: VAS at admission to our institution was 7.1 (0.4), VAS 6 weeks after surgery was 1.0 (0.3).LL at admission to our institution was 40.0 (2.1), LL 6 weeks after surgery was 48.0 (1.8). The difference was significant (p < 0.0005) with a high statistical power (1-ß = 0.99).Correlation of LL and VAS was significant (p < 0.01, r = -0.32). CONCLUSIONS: The increase of lumbar lordosis following surgery is significantly correlated to the decrease in the level of perceived pain in patients with a LDH and may be used as an additional tool to monitor the success of treatment in the investigated group of patients.

Signal Intensity of Lumbar Disc Herniations: Correlation With Age of Herniation for Extrusion, Protrusion, and Sequestration.

BACKGROUND: There is presently insufficient data on small groups of patients, without focus on time since herniation occurred and without establishing a valid method of measurement for signal intensity (SI) of a lumbar disc herniation (LDH) in a standard magnetic resonance imaging (MRI). SI could be reported in relation to SI of nucleus pulposus of herniated intervertebral disc, nucleus pulposus of a healthy "control" intervertebral disc, cerebral spinal fluid, or anterior anulus fibrosus. It is not known which signal intensity ratio (SIR) shows the highest correlation with time since onset of pain and how SIR of different Combined Task Forces (CTF)-types of herniation develop over time. METHODS: Out of 1053 patients, we enrolled 151 patients to a retrospective single-center analysis of standard MRIs of consecutive patients treated for LDH from February 2008 to December 2017 with confirmed (surgery, injection, or electrophysiologic testing) radicular pain by LDH and known exact date of onset of pain. We excluded patients < 18 or > 70 years, with chronical pain syndrome, spinal deformity, and history of prior spinal surgery on the affected spinal level. Because data did not show normal distribution, we assessed correlation by Spearman rank correlation coefficient. Correlation (R) and coefficient of correlation (CC) are reported. RESULTS: SI of LDH referenced by SI of nucleus pulposus of the affected intervertebral disc and CTF type "extrusion" showed the highest correlations with time since onset of pain (R: -0.893; CC: 79.7), followed by CTF-type "sequestration" (R: -0.356; CC: 12.7). CONCLUSIONS: SIR of extrusion referenced by nucleus pulposus of the affected intervertebral disc does show a high correlation with days since onset of herniation and may be applied to monitor changes of SI of LDH after herniation in standard MRIs of the lumbar spine.

Time in brace: where are the limits and how can we improve compliance and reduce negative psychosocial impact in patients with scoliosis? A retrospective analysis.

BACKGROUND: Brace treatment for adolescent idiopathic scoliosis (AIS) is generally prescribed for 18-23 hours per day, but the minimal time of brace wear per day to stop progression of AIS is still unclear. Compliance of patients with AIS with brace treatment is reported to be between 27% and 47% of the prescribed time, brace wear especially at school is often described as embarrassing by adolescent patients. It has been reported that a higher rate of compliance leads to a significantly lower rate of curve progression. Theoretically, prescribing brace treatment 16 hours instead of 23 hours per day (patients are allowed to attend school free of their brace) could lead to a higher rate of compliance, and subsequently reduce progression rate of patients with AIS. PURPOSE: To investigate if brace treatment 16 hours per day is noninferior to >16 hours with regard to curve progression, and if other clinical and demographic factors that might influence incidence and progression (apart from time of brace wear) of AIS can be identified. STUDY DESIGN: In a retrospective study, we investigated patients with AIS who had been admitted to our outpatient clinic and enrolled them in one of three groups: group 1 brace <12 hours per day, group 2 brace 12-16 hours per day, and group 3 brace >16 hours per day. PATIENT SAMPLE: Seventy-two patients met our inclusion criteria and were enrolled in our study, 61 female and 11 male patients. Twenty-eight were allocated in group 1, 13 in group 2, and 25 in group 3. OUTCOME MEASURES: Progression of Cobb angle with regard to brace wear per day was the main outcome measure. METHODS: Skeletally immature patients who presented from October 2010 to June 2013 with an AIS and a Cobb angle >20° were enrolled in our study and have been prescribed a Chêneau orthesis. Demographic parameters, progression of Cobb angle, and time of brace wear have been recorded. Groups 1, 2, and 3 of brace wear were analyzed for differences. RESULTS: The overall difference between the groups referring to increase of Cobb angle was significant (p<.05). Further analysis of groups 2 and 3 showed that the difference between these groups was not significant (p>.05). Apart from time of brace wear, no other factor showed any influence on curve progression. Smoking status of parents of our patients was significantly more often positive than in the general local population (p>.05). CONCLUSIONS: Twelve to 16 hours of brace wear per day did not lead to a higher progression rate of AIS compared with more than 16 hours in our study group. Our analysis showed that smoking status of parents possibly contributes to the risk of developing AIS; however, we did not find an impact on progression of scoliosis.

Epidemiology of adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis is a common disease with an overall prevalence of 0.47-5.2 % in the current literature. The female to male ratio ranges from 1.5:1 to 3:1 and increases substantially with increasing age. In particular, the prevalence of curves with higher Cobb angles is substantially higher in girls than in boys: The female to male ratio rises from 1.4:1 in curves from 10° to 20° up to 7.2:1 in curves >40°. Curve pattern and prevalence of scoliosis is not only influenced by gender, but also by genetic factors and age of onset. These data obtained from school screening programs have to be interpreted with caution, since methods and cohorts of the different studies are not comparable as age groups of the cohorts and diagnostic criteria differ substantially. We do need data from studies with clear standards of diagnostic criteria and study protocols that are comparable to each other.