Search

Study design A cervical biomechanical study. Objective We sought to demonstrate the three-dimensional (3D) intervertebral motion characteristics of the cervical spine in healthy volunteers using cone beam computed tomography (CBCT) combined with 3D-3D registration technology. Summary of background data No previous studies have used CBCT combined with 3D-3D registration technology to successfully documented in vivo three-dimensiona lintervertebral 6-DOF motions of the cervical spine. Methods Twenty healthy subjects underwent cervical (C1-C7) CBCT scans in seven functional positions. Segmented 3D vertebral body models were established according to the cervical CBCT images. A 3D-to-3D registration was then performed for each vertebral body in the different positions to calculate the 3D segmental motion characteristics in vivo. Results During flexion-extension, the range-of-motion (ROM) of C1-C2 and C4-C5 was significantly greater than the other segments. The average coupled axial rotation and lateral bending of each segment were between 0.6°and 3.2°. The average coupling translation in all directions were between 0.2 mm and 2.1 mm. During axial rotation, the ROM of C1-C2 was 65.8 ± 5.9°, which accounted for approximately 70% of all axial rotation. The motion and displacement of C1-C2 coupled lateral bending were 11.4 ± 5.2° and 8.3 ± 1.9 mm, respectively. During lateral bending, the ROM of C3-C4 was significantly greater than C1-C2, C5-C6, and C6-C7. The coupled axial rotation of C1-C2 was 34.4 ± 8.1°, and the coupled lateral translation was 3.8 ± 0.5 mm. The coupled superoinferior and anteroposterior translation of each cervical segment were between 0.1 mm and 0.6 mm. Conclusion CBCT combined with 3D-3D registration was used to accurately measure and record the ROMs of lateral bending, axial rotation, and flexion-extension in cervical vertebrae under physiological-load conditions. Our findings may contribute to the diagnosis of cervical spinal disease, the development of new surgical techniques, and the restoration of normal, cervical segmental movement.Level of Evidence: 3.

BackgroundFew reports have been conducted to comparing surgical results and safety evaluations between the different types of infections in geriatric patients with thoracolumbar infections. The aim of this study is to investigate the safety and efficacy of surgical treatment for thoracolumbar infections in elderly patients.Methods21 patients with pyogenic spondylodiscitis (PS) and 26 patients with tuberculous spondylodiscitis (TS) were enrolled in the study. All patients were treated using one-stage posterior debridement, decompression, and pedicle screw fixation. Comparison of operative safety parameters between the two groups. Clinical efficacy was evaluated using visual analogue scale (VAS) score, the American Spinal Injury Association (ASIA) grade, the short form (SF)-36 survey and Oswestry disability index (ODI) to determine patient quality of life pre- and post-operatively. Results Hospitalisation and intensive care unit duration in the PS group were significantly shorter than in the TS group (PConclusionOne-stage posterior debridement, decompression, interbody fusion, and internal fixation can be considered a safe and effective method of treating spinal infections in the elderly. This method can improve nerve function, reconstruct spinal stability, and enhance the quality of life of elderly patients. Both PS and TS who underwent surgery achieve similar clinical and radiological results.

BackgroundFew reports have been conducted to comparing surgical results and safety evaluations between the different types of infections in geriatric patients with thoracolumbar infections. The aim of this study is to investigate the safety and efficacy of surgical treatment for thoracolumbar infections in elderly patients.Methods21 patients with pyogenic spondylodiscitis (PS) and 26 patients with tuberculous spondylodiscitis (TS) were enrolled in the study. All patients were treated using one-stage posterior debridement, decompression, and pedicle screw fixation. Comparison of operative safety parameters between the two groups. Clinical efficacy was evaluated using visual analogue scale (VAS) score, the American Spinal Injury Association (ASIA) grade, the short form (SF)-36 survey and Oswestry disability index (ODI) to determine patient quality of life pre- and post-operatively. Results Hospitalisation and intensive care unit duration in the PS group were significantly shorter than in the TS group (PConclusionOne-stage posterior debridement, decompression, interbody fusion, and internal fixation can be considered a safe and effective method of treating spinal infections in the elderly. This method can improve nerve function, reconstruct spinal stability, and enhance the quality of life of elderly patients. Both PS and TS who underwent surgery achieve similar clinical and radiological results.

STUDY DESIGN Kinematics of the cervical spine was investigated using cone beam computed tomography (CBCT) images combined with three dimensions to three dimensions (3D-3D) registration technology in patients after anterior odontoid screw fixation (AOSF) surgery. OBJECTIVE The aim of this study was to investigate in vivo 3D cervical motion characteristics of patients who had undergone AOSF surgeries. SUMMARY OF BACKGROUND DATA AOSF surgery is a classic surgical method for the treatment of odontoid fracture, but there are few studies that investigated its effect on in vivo biomechanics of the cervical spine. Postoperative biomechanical characters of the atlantoaxial joint (C1-C2) and the caudal adjacent segment (C2-C3) have yet to be clarified. METHODS The study involved 14 patients subjected to a procedure of AOSF with lag screw. Subjects were matched with 14 healthy controls. All subjects underwent CBCT scanning of the cervical spine under seven functional positions. A 3D-3D registration was performed for each vertebra at each functional position to calculate the segmental motion characteristics. The ranges of motion (ROMs) of the C1-C2, C2-C3, and the overall cervical spine (C1-C7) for each of the functional positions were determined. RESULTS The ROMs of the AOSF group were significantly (P

Lumbar 3-joint complex degeneration is a multifactorial, pathological process. Previous studies included insufficient quantitative analyses to prove the relationship between disc degeneration and facet joint osteoarthritis (OA). We assessed the correlation between intervertebral disc and lumbar facet joint degeneration using computed tomography (CT) and magnetic resonance imaging (MRI) parameters. A total of 152 participants who underwent conventional MRI and CT in the clinostat position were included in this study. The presence of lumbar disc degeneration was identified using the Pfirrmann grading system, and the presence of lumbar facet joint degeneration was identified using the Weishaupt grading system. Facet tropism was defined as a divergence more than 7° between the facet joint angles of both sides at the same segment. The intervertebral disc heights were also measured. Most facet joint OA probably appeared at the segment with intervertebral disc degeneration of more than grade III. Facet joint OA was significantly exacerbated with the progression of disc degeneration grade. The intervertebral height significantly decreased with the progression of facet joint degeneration grades, except for grades 0 and 1. Our current study found that each individual joint degeneration influences the other 2 in the lumbar 3-joint complex. Facet tropism was significantly associated with lumbar disc degeneration. Narrowing of the intervertebral disc height probably aggravates the facet joint degeneration further at the same level.

To compare the clinical and radiographic results of unilateral pedicle screw fixation (UPSF) and bilateral pedicle screw fixation (BPSF) after unilateral transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative disc diseases (DDDs).A total of 63 patients who underwent UPSF or BPSF combined with unilateral TLIF at L4-L5 or L5-S1 in our hospital between 2014 and 2016 were included in this analysis. The perioperative outcomes and radiographic results were recorded at preoperative and postoperative follow-up. Fusion rates were determined according to the Bridwell-Lenke grading system. Clinical outcomes were evaluated using the visual analog scale, Oswestry Disability Index, and lumbar Japanese Orthopedic Association score.According to the perioperative assessment, the duration of operation, intraoperative and postoperative blood loss, duration of pain medication use, and hospital costs were significantly (P0.0001) lower in the UPSF group compared with the BPSF group. After a mean follow-up of 24 months, both the UPSF and BPSF groups showed significantly (P0.05) maintained disc height and segmental lordosis of the surgical segment and achieved similar clinical outcomes at the final postoperative follow-up. The impact on the cranial adjacent vertebral level was significantly (P0.05) less in the UPSF group than the BPSF group in the short term.UPSF techniques with TLIF can attain similar clinical efficiency as BPSF techniques in treating single-level low lumbar DDD, but with fewer surgical injuries and at lower cost. BPSF with TLIF likely causes more degeneration at the cranial adjacent segment compared with UPSF techniques. The long-term results require more study.

It is widely assumed that the grouping of the visual field first described by the Gestalt psychologists and the related phenomenon of texture segregation occur very early in the processing of visual information and involve preattentive processes. All the recent evidence supporting this assumption comes from visual search experiments in which the subject is actively looking for a target and attending to the stimulus. The question at issue is whether these kinds of patterns are perceived under conditions of inattention, i.e., when observers are not searching for them. We performed six experiments to determine whether texture segregation and grouping by similarity or proximity are perceived under conditions of inattention. On the first two trials subjects were asked to report the longer arm of a briefly presented cross which was surrounded by a pattern of ungrouped small elements. On the third trial and subsequent control trials these elements were configured into grouping patterns and subjects queried about them immediately following their line length reports. The results establish that neither texture segregation nor grouping by similarity of lightness or proximity are perceived under conditions of inattention. They support the conclusion that there is an earlier stage of processing than that referred to as preattentive.