Search Results (118)

Background: Robotic-assisted systems have transformed total knee arthroplasty (TKA), promising improved accuracy and intraoperative consistency, yet real-world data from non-academic centers remain limited. Objective: This study evaluates five-year clinical integration of a semi-autonomous, CT-based, robotic-arm-assisted TKA at a tertiary non-teaching hospital in Germany, focusing on planning accuracy, gap balancing, and intraoperative outcomes. Methods: We retrospectively analyzed all patients (n = 457) who underwent MAKO-assisted TKA from 2020 to 2025, performed by three orthopedic surgeons using a standardized subvastus approach. We assessed preoperative deformities, intraoperative alignment, implant sizing, and gap balancing. Surgical plans were adapted intraoperatively when indicated. Pre- vs. post-implantation values were compared using slopes to evaluate execution consistency. Results: Median patient age was 67.0 years (IQR: 60.0–75.0), with varus in 84.1% (7.0°, IQR: 4.0°–10.0°), valgus in 13.2% (3.0°, IQR: 1.5°–5.8°), and neutral alignment in 2.7%. Flexion contracture occurred in 80.4% (6.0°, IQR: 3.0–10.0%), hyperextension in 12.7% (2.0°, IQR: 1.5°–5.0°). Planning-to-execution consistency was high, even with plan adaptations. Slope values for alignment parameters were: tibial rotation in degrees (slope value: 1.0), femoral sagittal angle in degrees (0.8), tibial sagittal angle in degrees (0.9), coronal posterior condylar angle in degrees (0.9), femoral component size (1.0), tibial component size (1.0). Over 95% of cases showed ≤3.0° deviation between planned and final values. Bone resection concordance showed moderate agreement, with slopes from 0.8 (posterior medial femoral cut in mm) to 0.5 (lateral tibial cut in mm). Gap balancing improved at all stages, with reduced variability in medial/lateral extension and flexion gaps (all p < 0.05). Functional reconstruction showed significant improvements in extension, flexion, and deformities (all p < 0.001). Conclusions: Semi-autonomous, CT-based, robotic-arm-assisted TKA was successfully implemented in this non-academic setting, demonstrating acceptable intraoperative and functional reconstruction outcomes, supporting the feasibility of robotic-assisted surgery outside academic centers. Full article

Background/Objectives: This case represents the successful treatment of cervical spine injury from high-speed rear-impact motor vehicle collision and abnormal cervical kyphosis with left arm radiculopathy, utilizing conservative spine care rehabilitation methods. This patient was treated with a multimodal treatment approach integrating a cervical spine extension traction protocol. Subject and Methods: A 50-year-old male with a history of motor vehicle collision presented with left arm radiculopathy, as well as cervical and upper thoracic spine pain. Notably the cervical spine presented with kyphotic deformity. The patient presented, after a being struck during a rear-end motor vehicle collision, with neck, upper back, and left arm radiculopathy. Prescription medication and traditional chiropractic care proved ineffective for substantive symptom and quality-of-life improvement. Treatment frequency was three times per week for eight weeks using the Chiropractic Biophysics^® protocol of mirror image (MI^®) postural exercise, spinal adjustment, and cervical spinal traction. On completion of in-office care, the patient was treated monthly, performed home care at least three times per week, and was re-examined at one year. Results: Final examination after eight weeks of care showed significant improvement in cervical lordosis (21.8 degrees), resulting in reduced cervical kyphosis. The patient completed outcome indices before, during, and 12 months after cessation of active care, all indicating improvement. Conclusions: This case report demonstrates both subjective and objective improvement in cervical spine kyphosis and attendant symptoms. The successful treatment of chronic pain, peripheral weakness, and radiculopathy with long-term follow-up using CBP care is documented as well. The treatment was designed to improve sagittal balance and reduce radiographic abnormalities evincing spinal misalignment. Administration of subjective, objective, and health-related quality-of-life outcome indices during, following, and 12 months post-treatment are suggestive of long-term efficacy of Chiropractic BioPhysics^® (CBP) treatment methods. Larger studies are needed to substantiate this given the limitations of a case report. Full article

Children with cerebral palsy (CP) have impaired standing balance ability, caused by increased muscle tone, muscle weakness, and joint deformity. It is necessary to investigate standing balance for children with CP. Compared with postural stability assessment using force plates, OpenCap has the potential to be used utilized as a cost-effective standing balance assessment tool, providing details about the center of mass (CoM) and joint angles. This study aims to evaluate the feasibility of using OpenCap for standing balance assessment in children with CP by (i) examining the validity of OpenCap-based CoM parameters against force plate center of pressure (CoP) measures and (ii) exploring associations between joint angles and CoM displacement. Twenty-two children with CP completed standing balance trials on a force plate-based balance tester while two smartphones recorded synchronized videos for OpenCap processing. For the correlation between CoM parameters and CoP parameters, Pearson’s R values were from 0.39 to 0.94 between the two systems. After correcting the CoM parameters, the R² values ranged from 0.98 to 1.00. Regarding the relationship between the joint angles and CoM, maximum and minimum sagittal angles in the ankle were corrected with CoM displacement along the x-axis. These findings suggest that OpenCap may be a potential, cost-effective tool for standing balance assessment in children with CP. Full article

Background and Objectives: This study aimed to identify radiographic predictors and optimal cut-off values for determining the need for additional pedicle subtraction osteotomy (PSO) in patients with iatrogenic flatback syndrome following short-segment (≤3 levels) fusion surgery. Materials and Methods: From 2011 to 2022, a total of 49 patients who underwent deformity correction for iatrogenic flatback following short-segment fusion at a single institution were included. We divided all patients into group A (n = 33, only anterior column realignment, ACR) and group B (n = 16, ACR combined with PSO). Among group A patients, we further divided them into two subgroups: The Excessive group, who developed excessive anterior disc height distraction (EADH) during surgery, and the Non-excessive group, who did not. The Receiver Operating Characteristic (ROC) curve was used to determine the cut-off values for spinopelvic parameters associated with the decision to perform additional PSO. Results: Group A had a significantly lower number of previously fused segments compared to Group B (p < 0.001). Preoperative C7 sagittal vertical axis (C7SVA, p = 0.026) and its correction (p = 0.003) in group B were greater than those in group A. Group B showed a significantly more kyphotic preoperative fused segment angle (FSA) compared to Group A (p = 0.001). Postoperatively, EADH occurred in 7 patients (21.2%) in Group A, while no cases were observed in Group B. Subgroup analysis revealed that the dynamic segment angle (DA) was significantly lower in the Excessive group compared to the Non-excessive group (p < 0.001). The optimal cut-off values of preoperative radiographic parameters for selecting PSO were: C7-SVA > 242.8 mm, FSA > −3.2°, and DA < 4.3°. Conclusions: ACR alone and ACR combined with PSO showed satisfactory outcomes in patients with iatrogenic flat back. For selected patients with preoperative C7SVA > 242.8 mm, FSA > −3.2°, or DA < 4.3°, additional PSO may be reasonable to help optimize sagittal alignment. Full article

Background: Glioblastoma (GBM) is an aggressive brain tumor, with surgery being an integral part of treatment. Aggressive resections improve clinical outcomes but need to be balanced against potential functional impairment. Neuropsychological (NP) testing is an important tool neurosurgeons use to assess cognitive functioning. Importantly, associations between NP test scores and imaging biomarkers could enable a testable baseline by which to track patient outcomes over time and aid in presurgical counseling. Methods: We identified 44 patients diagnosed with primary GBM and who had detailed NP testing and presurgical imaging. Regression models for NP indices were created with tumor size, hemisphere, and lobar location as predictors. Lesion–symptom mapping (LSM) analyses were used to identify more detailed structure–function relationships. Results: Larger tumor volumes predicted worse attention, immediate memory, language, visuospatial, and overall NP performance (p < 0.05 for all). Left hemisphere involvement predicted worse attention, language, and immediate memory NP performance (p < 0.01 for all). Only visuospatial testing had lobar location significantly associated with worse scores (occipital lobe; p < 0.05). The LSM analyses identified areas around the left sagittal stratum as significantly associated with language performance (p < 0.05), with no other structure–function relationships being identified. Conclusions: These findings support the growing evidence that outside of a small number of truly critical regions, high-grade gliomas impair cognition generally, likely due to progressive tumor infiltration-associated neuroplasticity of complex parallel and interconnected networks. To investigate this, future studies should incorporate larger cohort sizes and should examine the relationship of glioma-induced network-level perturbations on cognitive decline. Full article

Background: We aimed to analyze radiographic sagittal balance parameters in patients who underwent a TLIF procedure for single-level degenerative spondylolisthesis with a mean follow-up of 8.6 years and to determine whether lumbar lordosis affects long-term clinical outcomes. Methods: This prospective study included 32 patients who underwent single-level TLIF surgery for degenerative spondylolisthesis. Radiographic analysis of sagittal balance parameters and clinical examination including Oswestry Disability Index (ODI) scores were performed preoperatively, postoperatively, and at the last follow-up. A minimal clinically important difference threshold of 30% was accepted as clinically relevant. Results: Mean postoperative lumbar lordosis (LL) and segmental lordosis (SL) failed to improve postoperatively; nevertheless significant improvements in short- and long-term postoperative ODI scores were demonstrated (p < 0.001). Thoracic kyphosis (TK) and global sagittal balance parameters shifted anteriorly after 8.6 years (p < 0.001), but this increase did not affect clinical outcomes. Conclusions: Adequate decompression and solid bone fusion are foremost required to achieve improved long-term clinical outcomes in single-level TLIF procedures. In our studied cohort, failure to improve lordosis did not impair clinical outcomes postoperatively. With aging, thoracic kyphosis and anterior malalignment increase, and after 8.6 years, clinical improvements are starting to become insignificant. Full article

Background/Objectives: The projected rise in limb amputations highlights the need for advancements in prosthetic technology. Current transtibial prosthetic designs primarily focus on sagittal plane kinematics but often neglect both the ankle kinematics and kinetics in the coronal plane, and the metatarsophalangeal joint, which play critical roles in gait stability and efficiency. This study aims to evaluate the combined effects of compliance in the coronal plane and a flexible toe joint on prosthetic gait using non-amputated participants as a model. Methods: We conducted gait trials on ten non-amputated individuals in the presence and absence of compliance in the coronal plane and toe compliance, using a previously developed three-degree-of-freedom (DOF) prosthetic foot with a prosthetic simulator. We recorded and analyzed sagittal and coronal kinematic data, ground reaction forces, and electromyographic signals from muscles involved in the control of gait. Results: The addition of compliance in the coronal plane and toe compliance had significant kinematic and muscular effects. Notably, this compliance combination reduced peak pelvis obliquity by 27%, preserved the swing stance/ratio, and decreased gluteus medius’ activation by 34% on the non-prosthetic side, compared to the laterally rigid version of the prosthesis without toe compliance. Conclusions: The results underscore the importance of integrating compliance in the coronal plane and toe compliance in prosthetic feet designs as they show potential in improving gait metrics related to mediolateral movements and balance, while also decreasing muscle activation. Still, these findings remain to be validated in people with transtibial amputations. Full article

Introduction: Synovitis and damage to natural stabilizers of many axial and peripheral joints make patients with rheumatoid arthritis particularly susceptible to sagittal balance disorders of the axial skeleton. This may determine the high individual variability of cervical spine deformities as well as differences in the rate of development of disease symptoms in these patients, such as radiculopathy and myelopathy. Methods: In the scientific literature, in addition to systemic factors, more and more attention is paid to work on biomechanical factors in the development of cervical spine instability. One of the methods for assessing the influence of biomechanical factors, which can also be used in everyday practice, is the analysis of radiological parameters of sagittal balance. Results: Among the selected sagittal balance parameters studied, a statistical relationship between C4 and C5 distance and the OI parameter has been found, indicating a relationship to a parameter that remains constant throughout an individual’s life in the group of patients with disease duration over 20 years. Conclusions: The development of instability and deformity in the subaxial segment of the cervical spine in patients with rheumatoid arthritis may be the result of insufficiently understood components of biomechanical factors; hence, further research in this field is necessary. Full article

Background and Objectives: We conducted a retrospective observational study. Background: While traditional rehabilitation approaches emphasize trunk muscle conditioning, emerging evidence suggests that leg muscle strength plays a critical role in postoperative functional mobility. Previous studies have focused on trunk muscle rehabilitation in patients with adult spinal deformity (ASD). However, recent findings suggest that leg muscle conditioning may be a better predictor of postoperative improvement. Strengthening the gluteal and iliopsoas muscles has been linked to improved sagittal balance, gait stability, and mobility, ultimately leading to enhanced surgical outcomes. This study examines the relationship between the preoperative functional cross-sectional area (FCSA) of trunk and leg muscles and postoperative improvement in mobility, as assessed by the Timed Up and Go (TUG) test, in patients undergoing surgery for ASD. Materials and Methods: Sixty-two patients (57 women, mean age 71.2 ± 7.1 years) who underwent ASD surgery between April 2017 and April 2024 were retrospectively analyzed. The FCSA of key muscles—psoas major (PM), erector spinae (ES), multifidus (MF), gluteus maximus (GM), and gluteus medius (GMed)—was measured using CT images. Patients were categorized into an improvement group and a non-improvement group based on whether they achieved the minimum clinically important difference (MCID) of −2 s in the TUG test 12 months after surgery. Propensity score matching (PSM) was applied to adjust for baseline differences between the groups. A significance level of 5% was used for all comparisons. Results: Thirty-three patients achieved a clinically meaningful improvement in TUG, while 29 did not. Before PSM, patients with worse preoperative TUG and Oswestry Disability Index (ODI) scores showed greater improvements (p < 0.01). After PSM, no significant differences were found between the groups in terms of age, sex, or BMI. However, the improvement group showed significantly greater FCSA values in PM (6.1 ± 2.3 mm² vs. 3.9 ± 1.5 mm², p = 0.021) and GM (19.9 ± 5.9 mm² vs. 15.3 ± 3.9 mm², p = 0.019). Conclusions: This study demonstrates that leg muscle quality, particularly that of the gluteus maximus and psoas major, is a significant predictor of postoperative mobility improvement in patients with ASD. These findings challenge the conventional focus on trunk muscles and suggest the inclusion of leg muscle training in preoperative rehabilitation strategies to enhance surgical outcomes. Full article

Mixed Martial Arts (MMA) is a highly dynamic combat sport that requires precise motor coordination and technical execution. Video-based motion analysis, including two-dimensional (2D) and three-dimensional (3D) motion capture systems, plays a critical role in optimizing movement patterns, enhancing training efficiency, and reducing injury risk. However, the comparative validity of 2D and 3D systems for evaluating punching mechanics under external stressors remains unclear. This study aimed to first validate the measurement agreement between 2D and 3D motion analyses during sagittal-plane punches, and second, to examine the impact of fatigue and balance disruption on arm kinematics and punch dynamics in elite MMA athletes. Twenty-one male MMA fighters (mean age: 24.85 ± 7.24 years) performed standardized straight right punches (SRPs) and swing punches (SPs) under three experimental conditions: normal, balance-disrupted, and fatigued. Participants were instructed to deliver maximal-effort punches targeting a designated striking pad placed at a consistent height and distance. Each punch type was executed three times per condition. Kinematic data were collected using the my Dartfish Express(version 7.2.0) app (2D system) and MaxPRO infrared motion capture system (3D system). Statistical analyses included Pearson’s correlation coefficients, one-way analysis of variance (ANOVA), and linear mixed models (LMMs). Strong correlations (r = 0.964–0.999) and high intraclass correlation coefficient (ICC) values (0.81–0.99) confirmed the high reliability of 2D analysis for sagittal-plane techniques. Fatigue significantly decreased punch velocity and impact force (p < 0.01), while increasing joint angle variability (p < 0.01). These findings highlight the complementary use of 2D and 3D motion capture methods, supporting individualized monitoring, adaptive technique evaluation, and performance optimization in combat sports. Full article

For the past two decades, the consideration of spinopelvic parameters, sagittal balance, and spine shape has gained importance in the diagnosis and optimal surgical management of painful adult spinal deformity. These principles are used with increasing frequency in the surgical planning and treatment of degenerative mechanical lower back pain. Several parameters exist to analyze both global and regional spinal balance. Chronic lower back pain due to degenerative disc disease, degenerative spondylolisthesis, or adult spinal deformity can be surgically managed in a multitude of ways ranging from simple decompression to multilevel arthrodesis with or without corrective osteotomies, depending on the presumed etiology of the pain, surgical planning, and the surgical goal. In surgical candidates, preoperative evaluation of spinopelvic parameters is paramount, as increasing evidence shows that restoration of the shape of the spine while respecting these parameters improves patient-reported outcome measures (PROMs), decreases re-operation rates, and reduces mechanical complications such as proximal junctional kyphosis/failure (PJK/PJF), distal junctional kyphosis/failure (DJK/DJF), adjacent segment disease (ASD), and rod fracture. This review provides a conceptual analysis of spinopelvic alignment, global and regional sagittal balance, and the restoration of the spine’s shape in relation to patient outcomes during surgical treatment of degenerative spine disorders. Full article

Background and Objectives: Degenerative cervical myelopathy (DCM), a major subtype of degenerative cervical disorders, presents with diverse sagittal alignment patterns. However, radiography-based phenotyping remains underexplored. This study aimed to identify distinct cervical alignment subgroups using unsupervised clustering analysis and to explore their potential clinical relevance. Materials and Methods: We analyzed 1371 lateral cervical radiographs of patients with DCM. C3–C7 sagittal vertical axis (SVA), lordosis, vertical length, and curved length were determined. K-means clustering was applied, and the optimal cluster number was determined using the elbow method and silhouette analysis. Clustering validity was assessed using the Calinski–Harabasz and Davies–Bouldin indices. Results: The final clustering solution was validated with a high Calinski–Harabasz index (1171.70) and an acceptable Davies–Bouldin index (0.99) at k = 3, confirming the stability and robustness of the classification. Cluster 1 (forward-head type) exhibited low lordosis (8.3° ± 4.7°), moderate SVA (95.9 ± 60.2 mm), and a compact cervical structure, consistent with kyphotic alignment and forward-head displacement. Cluster 2 (normal) showed the highest lordosis (24.1° ± 6.8°), moderate SVA (70.6 ± 50.2 mm), and balanced sagittal alignment, indicating a biomechanically stable cervical posture. Cluster 3 (long-neck type) displayed the highest SVA (135.6 ± 76.7 mm), the longest vertical and curved lengths, and moderate lordosis, suggesting a structurally elongated cervical spine with anterior head displacement. Significant differences (p < 0.01) were observed across all clusters, confirming distinct phenotypic patterns in cervical sagittal alignment. Conclusions: This exploratory clustering analysis identified three distinct radiographic phenotypes of DCM, reflecting biomechanical heterogeneity. Although prospective studies linking these phenotypes to clinical outcomes are warranted, our findings provide a framework for personalized spinal care in the future. Full article

Background/Objectives: There are many concerns regarding adjacent segment disease after lumbar spinal fusion. However, there are few studies that analyze risk factors by classifying adjacent segment disease (ASD) by onset. This study aimed to investigate related factors according to the period of occurrence of ASD in mid- to long-term follow-up patients after lumbar spinal fusion. Methods: We analyzed 139 patients who underwent ≤3-segment lumbar fusion for degenerative disease with a minimum 5-year follow-up from a consecutive series of 457 patients. Risk factors for adjacent segment disease (ASD) and early ASD (E-ASD, occurring ≤5 years) were evaluated, including patient factors (age, sex, BMI), preoperative factors (diagnosis, Pfirrmann grade), surgical factors (fusion method, number of segments), and radiological parameters (lumbar lordosis, fused segment angle, PI-LL mismatch). Multivariable Cox proportional hazards modelling and Kaplan–Meier survival analysis were performed to identify independent risk factors. Results: A total of 28 patients underwent revision surgery for ASD. Among them, 14 patients developed E-ASD. In the analysis of risk factors for ASD, the fusion method, and the postoperative PI-LL were statistically significant (p = 0.003, HR = 4.670, and p = 0.008, HR = 3.102, respectively). Regarding E-ASD, the fusion method was statistically significant (p = 0.038, HR = 5.444). The cumulative survival rate of ASD was 93.7% at 5 years and 76.4% at 10 years. Conclusions: ASD risk factors vary temporally after fusion surgery. Early ASD is primarily associated with the PLIF technique, while long-term risk relates to both the fusion method and sagittal alignment. Surgical planning should consider both the fusion technique and sagittal balance optimization to minimize ASD risk. Full article

This study aimed to investigate the relationship between visual system parameters (visual acuity and refractive error) and postural balance under controlled conditions in elite football players. Visual acuity (monocular and binocular) and refractive errors were assessed in 34 male athletes using retinoscopy and subjective refraction. Postural stability was assessed with the Cyber-Sabots™ platform, recording the center of pressure (CoP) metrics, including sway amplitude, velocity, and distribution area. Visual and postural parameter correlations were assessed using Pearson’s test (p < 0.05). Athletes demonstrated good binocular visual acuity (−0.03 ± 0.09 logMAR) and were predominantly emmetropic. Visual acuity and postural parameters showed significant negative correlations, whereby visual acuity was associated with reduced CoP displacement (r = −0.352) and sway area (r = −0.367), indicating enhanced stability. Hyperopia and oblique astigmatism were moderately correlated with increased sway (r = 0.343) and antero-posterior sway amplitude in the sagittal plane (r = 0.324). Anisometropia showed moderately negative correlations with antero-posterior control (r = −0.421), suggesting a disruptive effect on postural stability. The postural analysis showed adaptations characteristic of football players, including anterior body inclination, increased forefoot loading, and medio-lateral sway. Romberg’s quotients highlighted significant visual input reliance for maintaining postural balance. Visual acuity, refractive errors, and interocular refractive asymmetries significantly influence postural stability in elite football players. These results support incorporating visual function assessment into training and injury prevention in elite sports. Full article

Background/Objectives: Atrophy of the paraspinal and psoas major muscles is closely linked to sagittal malalignment in adult spinal deformity (ASD). However, most studies overlook the balance between these muscle groups. This study investigates the relationship between trunk muscle balance and sagittal alignment in ASD patients. Methods: A single-institution database was reviewed for patients with sagittal malalignment (PT > 20° and PI–LL > 10°). Standard sagittal parameters were measured based on standing X-rays. The cross-section area (CSA) of trunk posterior muscles (CSA^P: erector spinae and multifidus) and anterior muscles (CSA^A: psoas) at L4 were measured based on a T2-weighted MRI. Patients with prior lateral fusions were excluded. Muscle balance was evaluated by the CSA ratio of trunk posterior to anterior muscles (CSA^P/A). The relationship between sagittal alignment parameters and CSA^P, CSA^A, as well as CSA^P/A were analyzed using linear and quadratic regressions. Akaike information criteria (AIC) compared model fit. Subgroup analyses examined the relationship between sagittal alignment changes and different CSA^P/A levels. Results: A total of 112 patients met inclusion and exclusion criteria. CSA^P correlated linearly with SS (r² = 0.057, p = 0.011), PT (r² = 0.043, p = 0.028), and T4–L1PA mismatch (r² = 0.044, p = 0.027). CSA^A showed no significant linear or quadratic relationships with sagittal spinal alignment parameters. In contrast, CSA^P/A was quadratically associated with LL (r² = 0.056, p = 0.044), SS (r² = 0.134, p < 0.001), PI (r² = 0.096, p = 0.004), L1PA (r² = 0.114, p = 0.001), and T4–L1PA mismatch (r² = 0.094, p = 0.005). Quadratic models of CSA^P/A consistently had higher r² and lower AIC values compared to the linear models of CSA^P for most sagittal alignment parameters, especially in SS, PI, L1PA, and T4–L1PA mismatch (AIC difference ≥4). Higher CSA^P/A is correlated to larger PI (and consequently, larger LL, SS, and L1PA). Conclusions: Trunk posterior–anterior muscle balance (CSA^P/A) demonstrates a stronger relationship with sagittal alignment than individual muscle metrics. Quantitative MRI-based definitions of sarcopenia may need to be adjusted for PI. Full article