OBJECTIVE. To report the surgical technique and clinical results for the treatment of basilar invagination (BI) with atlantoaxial dislocation (AAD) by d

Background: Clinical diagnosis and therapy for the lumbar disc herniation requires accurate vertebra segmentation. The complex anatomical structure and the degenerative deformations of the vertebrae makes its segmentation challenging. Methods: An improved level set method, namely edge- and region-based level set method (ERBLS), is proposed for vertebra CT images segmentation. By considering the gradient information and local region characteristics of images, the proposed model can efficiently segment images with intensity inhomogeneity and blurry or discontinuous boundaries. To reduce the dependency on manual initialization in many active contour models and for an automatic segmentation, a simple initialization method for the level set function is built, which utilizes the Otsu threshold. In addition, the need of the costly re-initialization procedure is completely eliminated. Results: Experimental results on both synthetic and real images demonstrated that the proposed ERBLS model is very robust and efficient. Compared with the well-known local binary fitting (LBF) model, our method is much more computationally efficient and much less sensitive to the initial contour. The proposed method has also applied to 56 patient data sets and produced very promising results. Conclusions: An improved level set method suitable for vertebra CT images segmentation is proposed. It has the flexibility of segmenting the vertebra CT images with blurry or discontinuous edges, internal inhomogeneity and no need of re-initialization.

Background: Oblique lumbar interbody fusion (OLIF) is a minimally invasive technique performed through the antero-oblique trajectory to address a wide range of lumbar pathologies. However, it can lead to complications. We reviewed the results of OLIF and discussed the effective methods to avoid such complications. Methods: Seventy-nine consecutive patients who underwent OLIF between May 2016 and July 2019 were retrospectively analyzed. They were divided into three groups: stand-alone, posterior, and lateral fixation, according to whether they were followed up with auxiliary internal fixation as well as the fixation methods. Preoperative and last follow-up visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were used to assess the improvement in the lower back and leg pain as well as neurological conditions. We analyzed intervertebral disc height (DH), segmental lumbar lordotic angle (SLL), lumbar lordotic angle (LL), pelvic tilt (PT), pelvic incidence-lumbar lordosis (PI-LL) mismatch, and the cross-section area (CSA) on axial magnetic resonance imaging (MRI) image in different groups. Complications, including thigh symptoms, cage subsidence, neurological injury, and vascular injury, were also noted. Results: Seventy-nine patients were followed up postoperatively for 23.2±11.5 (range, 12–48) months. Forty-eight (61%) patients underwent stand-alone surgery (without fixation), 15 (19%) patients underwent supplemental percutaneous pedicle screw fixation (posterior fixation), and 16 (20%) patients underwent lateral vertebral instrumentation (lateral fixation). In all three groups, the VAS score and the ODI score had significantly decreased at the final follow-up compared to pre-operation. The DH, SLL, LL, CSA, PT, and PI-LL mismatch had also improved by final follow-up. The most common approach-related complication was thigh symptoms. Of the 79 patients, ipsilateral transient psoas paresis occurred in 9 (11.4%), ipsilateral transient quadriceps weakness in 2 (2.5%), and groin/thigh numbness and pain in 17 (21.5%). Cage subsidence occurred in 8 (10.1%) patients, including five cases of grade 0, one of grade I, and two of grade II. Three (3.8%) patients in this study had a vascular injury. Conclusions: OLIF is a minimally invasive and effective technique for dealing with degenerative lumbar diseases. However, it should also be noted that this approach carries risks of complications.

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been employed in increasing cases compared with open TLIF (Open-TLIF). However, it is uncertain whether the advantages of MI-TLIF can also be specifically applied in obese patients. Therefore, the current study was thereby carried out aiming to compare the outcomes of MI-TLIF with those of Open-TLIF in obese patients with lumbar degenerative diseases. Electronic databases were systemically retrieved from construction to May 2017. Meanwhile, the odds ratio (OR), mean difference (MD) and 95% confidence intervals (CI) were determined. A total of 7 observational cohort studies were enrolled into the current meta-analysis. The results indicated that, compared with Open-TLIF group, MI-TLIF could remarkably reduce the operative time (P = 0.002), intraoperative blood loss (P < 0.001), postoperative drainage (P = 0.01), length of stay (P < 0.001) and incidence of complications (P < 0.001). In addition, MI-TLIF could also lead to markedly lower early back pain-Visual Analog Scale (BP-VAS) score than that of Open-TLIF (P < 0.001), but no statistically significant differences were found in Oswestry Disability Index (ODI), late BP-VAS, early leg pain-VAS (LP-VAS) and late LP-VAS scores. MI-TLIF may be a more preferred choice for obese patients undergoing spinal surgery. However, differences in the long-term functional and pain outcomes between MI-TLIF and Open-TLIF remain a source of controversy, which should be further verified in future randomized-control trials.