Background: Osteotomies aimed at correcting adult spinal deformity are associated with higher complications and perioperative morbidity. Recently, oblique lumbar interbody fusion (OLIF) was introduced for degenerative lumbar diseases. The aim of our study is to demonstrate the effectiveness of OLIF on the management of adult degenerative lumbar deformity (ADLD). Materials and Methods: Patients with ADLD who underwent deformity correction and decompression using OLIF and posterior instrumentation were enrolled. For radiologic evaluation, Cobb's angle (CA), sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), sacral slope (SS), and pelvic incidence (PI) were evaluated. Visual analog scale (VAS), Oswestry disability index (ODI), and perioperative parameters were recorded for clinical evaluation. Results: Fifteen patients with a mean age of 67 years (63–74 years) were enrolled prospectively and an average of 3 OLIFs (range 1–4) was performed. Posterior instrumentations were done at average of six levels (range 4–8). The mean operative blood loss was 863 ml (range 500–1400 ml) with a mean surgical duration of 7 h (range 3–11 h). SVA, TK, LL, CA, PT, and SS showed significant correction ( P < 0.05) in immediate postoperative period and all parameters except TK were maintained at final followup. At the end of 24 months of average followup, 86% (13/15) showed fusion. VAS (leg pain), VAS (back pain), and ODI improved by 74% (range 40–100), 58% (range 20%–80%), and 69.5% (range 4%–90%), respectively. There were two major complications requiring revision (1 infection and 1 adjacent vertebral body fracture). Transient hip weakness present in two patients (13%) recovered within 6 weeks. Conclusions: OLIF gives favorable short term clinical and radiological outcomes in patients of ADLD. It could potentially reduce the need for morbid pelvic fixation and posterior osteotomies in patients with degenerative lumbar deformity.

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Study DesignA retrospective study of radiographic parameters of patients who underwent lumbar spinal pedicle screw insertion.PurposeThe optimal length of pedicle screws is often determined by the lateral radiograph during minimally invasive surgery (MIS). Compared with open techniques, measuring the precise length of screws or assessing the cortical breach is challenging. This study aims to ascertain the optimal pedicle screw lengths on intraoperative lateral radiographs for L1–L5.Overview of LiteratureResearch has revealed that optimal pedicle screw length is essential to optimize fixation, especially in osteoporotic patients; however, it must be balanced against unintentional breach of the anterior cortex, risking injury to adjacent neurovascular structures as demonstrated by case reports.MethodsWe reviewed intra- and postoperative computed tomography scans of 225 patients who underwent lumbar pedicle screw insertion to ascertain which of the inserted screws were ‘optimal screws.’ The corresponding lengths of these screws were analyzed on postoperative lateral radiographs to ascertain the ideal position that a screw should attain (expressed as a percentage of the entire vertebral body length).ResultsWe reviewed 880 screws of which 771 were optimal screws. We noted a decreasing trend in average optimal percentages of insertion into the vertebral body for pedicle screws going from L1 (average=87.60%) to L5 (average=78.87%). The subgroup analysis revealed that there was an increasing percentage of screws directed in a straight trajectory from L1 to L5, compared to a medially directed trajectory.ConclusionsDuring MIS pedicle screw fixation, this study recommends that pedicle screws should not exceed 85% of the vertebral body length on the lateral view for L1, 80% for L2–L4, and 75% for L5; this will minimize the risk of anterior cortical breach yet maximize pedicle screw purchase for fixation stability.

BACKGROUND:The study aims at evaluation of spinopelvic parameters in an Indian population in a sample composed of asymptomatic individuals. METHODS: 84 healthy adult individuals were evaluated. The exclusion criteria included spinal deformity, spine degenerative or infective condition and improper radiograph study. In each radiograph the sagittal balance and spinopelvic parameters were evaluated, including vertical sagittal axis, sacral slope, pelvic tilt and pelvic incidence. RESULTS: Data obtained in this study were in accordance to International literatures. No significant variation between genders was obtained for various parameters. The mean values of Pelvic Incidence, Sacral Slope and Pelvic Tilt in healthy Indian Population is 49.4°±7.6°, 37.4°±6.6° and 13.9°±5.8° respectively. CONCLUSION: There were no differences in any radiographic parameter between males and females in the present study. Further, the values obtained are comparable with the values presented as normal in the literature. The Indian and European populations shows significance in pelvic incidence and sacral slope which were higher in European populations and Indian and Korean population showed significant difference in pelvic tilt which was lower in Korean population.

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