Associations between gait performance and pain intensity, psychosocial factors, executive functions as well as prefrontal cortex activity in chronic low back pain patients: A cross-sectional fNIRS study.

Introduction: Activities of daily living, such as walking, are impaired in chronic low back pain (CLBP) patients compared to healthy individuals. Thereby, pain intensity, psychosocial factors, cognitive functioning and prefrontal cortex (PFC) activity during walking might be related to gait performance during single and dual task walking (STW, DTW). However, to the best of our knowledge, these associations have not yet been explored in a large sample of CLBP patients. Method: Gait kinematics (inertial measurement units) and PFC activity (functional near-infrared spectroscopy) during STW and DTW were measured in 108 CLBP patients (79 females, 29 males). Additionally, pain intensity, kinesiophobia, pain coping strategies, depression and executive functioning were quantified and correlation coefficients were calculated to determine the associations between parameters. Results: The gait parameters showed small correlations with acute pain intensity, pain coping strategies and depression. Stride length and velocity during STW and DTW were (slightly to moderately) positively correlated with executive function test performance. Specific small to moderate correlations were found between the gait parameters and dorsolateral PFC activity during STW and DTW. Conclusion: Patients with higher acute pain intensity and better coping skills demonstrated slower and less variable gait, which might reflect a pain minimization strategy. Psychosocial factors seem to play no or only a minor role, while good executive functions might be a prerequisite for a better gait performance in CLBP patients. The specific associations between gait parameters and PFC activity during walking indicate that the availability and utilization of brain resources are crucial for a good gait performance.

Spondylodiscitis in Geriatric Patients: What Are the Issues?

STUDY DESIGN: Review article. OBJECTIVES: A review of literature on the treatment of pyogenic spondylodiscitis in geriatric patients was performed with the aim to give an overview about these special patients and a recommendation on necessary diagnostics as well as conservative and operative treatment options. METHODS: A systematic computerized literature search was done by the spondylodiscitis working group of the German Society for Orthopedics and Trauma Surgery. RESULTS: Spondylodiscitis has an increasing incidence by age with a peak at 75 years or older. The 1-year mortality without an appropriate treatment is with 15 to 20% extremely high. Pathogen detection is the essential diagnostic step and the basis for a sufficient antibiotic treatment. Geriatric patients have initially less elevated inflammatory parameters. Compared to younger patients. They have a longer length of hospital stay and take longer for CRP normalization. Even the outcome between conservative and operative treatment is comparable after one year. Patients with spinal instability, immobilizing pain, epidural abscess, and newly emerged neurological deficits should be considered for operative treatment. CONCLUSIONS: The treatment of geriatric patients with pyogenic spondylodiscitis must take into account that these patients usually have multiple comorbidities. The main goals are resistance-based antibiotics and the shortest possible time of immobilization of the patient.

Can artificial intelligence support or even replace physicians in measuring sagittal balance? A validation study on preoperative and postoperative full spine images of 170 patients.

PURPOSE: Sagittal balance (SB) plays an important role in the surgical treatment of spinal disorders. The aim of this research study is to provide a detailed evaluation of a new, fully automated algorithm based on artificial intelligence (AI) for the determination of SB parameters on a large number of patients with and without instrumentation. METHODS: Pre- and postoperative sagittal full body radiographs of 170 patients were measured by two human raters, twice by one rater and by the AI algorithm which determined: pelvic incidence, pelvic tilt, sacral slope, L1-S1 lordosis, T4-T12 thoracic kyphosis (TK) and the spino-sacral angle (SSA). To evaluate the agreement between human raters and AI, the mean error (95% confidence interval (CI)), standard deviation and an intra- and inter-rater reliability was conducted using intra-class correlation (ICC) coefficients. RESULTS: ICC values for the assessment of the intra- (range: 0.88-0.97) and inter-rater (0.86-0.97) reliability of human raters are excellent. The algorithm is able to determine all parameters in 95% of all pre- and in 91% of all postoperative images with excellent ICC values (PreOP-range: 0.83-0.91, PostOP: 0.72-0.89). Mean errors are smallest for the SSA (PreOP: -0.1° (95%-CI: -0.9°-0.6°); PostOP: -0.5° (-1.4°-0.4°)) and largest for TK (7.0° (6.1°-7.8°); 7.1° (6.1°-8.1°)). CONCLUSION: A new, fully automated algorithm that determines SB parameters has excellent reliability and agreement with human raters, particularly on preoperative full spine images. The presented solution will relieve physicians from time-consuming routine work of measuring SB parameters and allow the analysis of large databases efficiently.

Effects of a multimodal exercise intervention on physical and cognitive functions in patients with chronic low back pain (MultiMove): study protocol for a randomized controlled trial.

BACKGROUND: Chronic low back pain (CLBP) is a common medical condition in adults over the age of 50. It is associated with severe disability, ranging from physical impairments to psychosocial distress. Since current treatments provide only small to moderate short-term effects, alternative interventions are required, whereby guidelines recommended multimodal approaches. Dancing can be considered as an inherently multimodal approach, as it requires a combination of physical and cognitive functions. Furthermore, it has already been applied effectively in neurorehabilitation. Therefore, it seems promising to merge a dance-therapeutic component together with motor-cognitive, strength and flexibility exercises in a novel multimodal treatment (MultiMove) to target the impaired everyday mobility and cognition of CLBP patients. The aim of this study is to analyse specific physical, cognitive and psychosocial effects of MultiMove in CLBP patients. METHODS: A prospective, two-arm, single-blinded, randomized controlled trial will be conducted with an estimated sample size of 100 CLBP patients, assigned to either the MultiMove group or a control group. The intervention group will receive MultiMove twice a week for 60 min each over a period of 12 weeks. The primary outcome will be the mobility and function of the lower extremities assessed by the Timed Up-and-Go Test. Secondary outcomes comprise further physical and physiological functions (e.g. gait variability and haemodynamic response in the prefrontal cortex during motor-cognitive dual tasks), subjective health state (e.g. disability in daily life), executive functions (e.g. cognitive flexibility) and psychosocial aspects (e.g. kinesiophobia). Measures will be taken at baseline, after the intervention and at a 12-week follow-up. It is assumed that MultiMove improves the mentioned outcome parameters. DISCUSSION: The combined assessment of changes in physical and cognitive functions as well as neuropsychological aspects in response to MultiMove will allow a better understanding of the motor-cognitive adaptations induced by multimodal exercises in CLBP patients. The specific conclusions will lead to recommendations for the conservative treatment approach in this clinically relevant patient group. TRIAL REGISTRATION: German Clinical Trial Register (ID: DRKS00021696 / 10.07.2020), https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021696.

PSO without neuromonitoring: analysis of peri-op complication rate after lumbar pedicle subtraction osteotomy in adults.

PURPOSE: A decompensated sagittal imbalance has been associated with worsening health-related quality of life outcomes and increasing pain. Significant improvement in sagittal balance can be achieved using a pedicle subtraction osteotomy (PSO); however, this procedure has a high complication profile. A lumbar PSO has the advantages of direct visualization of all neural structures and safer retraction of the thecal sac. Sacrificing neuromonitoring may reduce anaesthesia time and lead to improved cost effectiveness of the surgery. However, there are no studies analyzing the complication rate of lumbar PSO without the use of neuromonitoring. We hypothesize that the neurologic complication rate remains comparable to published studies even without the use of intraoperative neuromonitoring. METHODS: The medical records of all patients of a single institution who received a lumbar PSO for sagittal imbalance between July 2012 and June 2014 were retrospectively analyzed. All surgeries were performed by the first author and without the use of intraoperative neuromonitoring. We analyzed the 30-day complication rate. RESULTS: Twenty-two patients were included in this study. The average age at surgery was 67 years. 16 patients had at least one previous lumbar surgery. The average fusion length was seven segments. All patients were instrumented to the sacrum and 19 patients additionally received spinopelvic instrumentation. The average amount of focal correction was 28°. The average surgical time was 362 min and blood loss was 2302 mL. A total of eight patients with complications were identified. There was a new neurologic postoperative deficit in two patients presenting as a foot drop. Five patients had an unplanned revision surgery. CONCLUSION: Historically, PSOs are associated with a high surgical complication rate and our results show comparable outcomes and complications to those previously reported. In our series, the absence of neuromonitoring in lumbar PSOs does not appear to increase the risk of neurological injury.

Biomechanical evaluation of meniscal root repair: a porcine study.

PURPOSE: Meniscal root repair is commonly practised using transtibial pull-out sutures. The purpose of the study was to investigate whether these are effective in restoring contact of the root to its footprint and a normal loading pattern of the cartilage under restricted loading conditions as used post-operatively. METHODS: First, a transtibial pull-out suture was simulated using porcine menisci (n = 10). It was repetitively loaded (100×; 1-10 N) and the elongation of the suture determined. In the second part of the study, porcine knees (n = 8) were subjected to repetitive low-level femoro-tibial loads (50 cycles; 100 N). A displacement sensor measured the deformation of the cartilage in the area of femoro-tibial contact. The residual deformation of the cartilage, which results from its viscoelastic behaviour, was determined as a measure of the local stress. Three scenarios were investigated: meniscal root intact, detached, and repaired. RESULTS: Repetitive loading caused a median suture elongation of 3.8 mm. Residual deformation of the cartilage was increased (p = 0.047) with the root detached. Root repair could not restore it to normal (n.s.). CONCLUSIONS: In this model, meniscus root repair was not effective in restoring the normal loading pattern of the cartilage because cyclic loading caused an elongation of the repair. CLINICAL RELEVANCE: In practice, this effect might impair the healing of repaired meniscal roots to the tibial bone.

Small ubiquitin-like modifier 1 [corrected] mediates the resistance of prosthesis-loosening fibroblast-like synoviocytes against Fas-induced apoptosis.

OBJECTIVE: To study the expression of small ubiquitin-like modifier 1 (SUMO-1) in aseptic loosening of prosthesis implants and to investigate its role in regulating the susceptibility of prosthesis-loosening fibroblast-like synoviocytes (FLS) to Fas-induced apoptosis. METHODS: Specimens of aseptically loosened tissue were obtained at revision surgery, and the expression of SUMO-1 was analyzed by in situ hybridization. SUMO-1 levels in FLS were determined by quantitative polymerase chain reaction and Western blot analysis. Immunohistochemistry and confocal microscopy were used to study the subcellular localization of SUMO-1. The functional role of SUMO-1 in Fas-induced apoptosis of prosthesis-loosening FLS was investigated by small interfering RNA-mediated knockdown of SUMO-1 and by gene transfer of the nuclear SUMO-specific protease SENP1. RESULTS: SUMO-1 was expressed strongly in aseptically loosened tissue and was found prominently at sites adjacent to bone. Prosthesis-loosening FLS expressed levels of SUMO-1 similar to the levels expressed by rheumatoid arthritis (RA) FLS, with SUMO-1 being found mainly in promyelocytic leukemia protein nuclear bodies. Knockdown of SUMO-1 had no effect on spontaneous apoptosis but significantly increased the susceptibility of prosthesis-loosening FLS to Fas-induced apoptosis. Gene transfer of the nuclear SUMO-specific protease SENP1 reverted the apoptosis-inhibiting effects of SUMO-1. CONCLUSION: These data suggest that SUMO-1 is involved in the activation of both RA FLS and prosthesis-loosening FLS by preventing these cells from undergoing apoptosis. Modification of nuclear proteins by SUMO-1 contributes to the antiapoptotic effects of SUMO-1 in prosthesis-loosening FLS, providing evidence for the specific activation of sumoylation during their differentiation. Therefore, SUMO-1 may be an interesting target for novel strategies to prevent aseptic prosthesis loosening.