Purpose
This study aimed to evaluate the predictive performance of preoperative computed tomography–based Hounsfield unit (HU) and magnetic resonance imaging-based vertebral bone quality score (VBQS) for cage subsidence after 1- to 2-level oblique lumbar interbody fusion (OLIF), and whether it differs by intraoperative cage placement position.
Methods
Ninety-one OLIF levels in 54 patients (2015–2022) were retrospectively reviewed in this single-center cohort. Subsidence was defined as ≥2 mm middle disc-height reduction or ≥2 mm cage protrusion at 1 year. Multivariable logistic regression with cluster-robust standard errors estimated adjusted odds ratios (OR); the pre-specified primary test was the lower-instrumented-vertebra HU×cage-position interaction.
Results
Subsidence occurred in 24 of 91 levels (26.4%). Each one-standard-deviation decrease in lower-instrumented-vertebra HU was independently associated with subsidence (adjusted OR, 0.40; 95% confidence interval, 0.20 to 0.81; p=0.011); VBQS was not. The subsidence group included more osteoporosis-range levels (<110 HU; 62.5% vs. 25.4%, p=0.003). The interaction was not significant (p=0.553), but the HU effect concentrated in middle-placed cages (adjusted OR, 0.345; p=0.012) and attenuated in anterior-placed cages (OR, 0.50; p=0.185).
Conclusion
Lower-instrumented-vertebra HU is an independent predictor of cage subsidence after 1- to 2-level OLIF, most evident in middle-placed cages.

Purpose
To evaluate the impacts of regional and socioeconomic factors on adolescent idiopathic scoliosis (AIS) diagnosis and treatment using national datasets of the Korean National Health Insurance System. The prevalence of, and therapeutic trends in, AIS are affected by a variety of environmental factors.
Materials and Methods
We analyzed random samples from datasets (10% of all entries) between 2012 and 2018, including in terms of patient demographics, residential status (a “special city”, and urban, and rural regions) and socioeconomic status (SES) based on health insurance premiums (which distinguish National Health Insurance and Medical Aid [MA] beneficiaries).
Results
The AIS prevalence was approximately 1.6-fold higher in females than in males, whereas the rate of male surgery was approximately 1.5-fold higher than that in females. AIS prevalence was higher among National Health Insurance beneficiaries (in all years), whereas the surgery rate was higher among MA beneficiaries (in most years). In all years, AIS prevalence was significantly higher among special city residents than in urban and rural residents. However, the surgical treatment rates were higher in the latter regions.
Conclusions
Our nationwide evaluation revealed AIS prevalence rates and therapeutic trends. AIS epidemiology varies by region and economic status.

Numerous improvements in minimally invasive spine surgery (MISS) have been made during the past decade. Classic treatment methods have reserved surgical intervention for trauma patients with neurological compromises or instability. When used in thoracolumbar spine trauma management, MISS should achieve the similar results as classic treatment with less morbidity.(1) In the past decade, minimally invasive surgical (MIS) techniques for spine surgery have been increasingly used. The goal of minimally invasive surgery is to decrease surgical morbidity through decreased soft-tissue dissection providing similar structural stability as classic techniques. An increasing number of studies is reporting good clinical and radiographic outcomes with MIS techniques. However, the literature is lacking high-quality evidence comparing these newer techniques to classic treatments. In the future, development of techniques can expand the indications and treatment possibilities in spine trauma treatment. We reviewed the current literatures to clarify the indications of minimally invasive techniques with spinal trauma.

Many techniques have been introduced and performed, with different strengths and benefits. The lateral lumbar interbody fusion techniques (direct lateral lumbar interbody fusion [DLIF] and oblique lateral interbody fusion [OLIF]) have yielded good results for elderly patients. These are useful options for elderly patients with high risk of complications with traditional approaches.

Although metastatic lung adenocarcinoma in the spinal cord is rare, it can be diagnosed by positron emission tomography and computed tomography (PET/CT) scan with high sensitivity during the early disease stage. A clinical and radiographic review was performed to present a rare case of an intradural intramedullary adenocarcinoma metastasis in the spinal cord with a negative PET/CT scan. A 75-year-old man with a diagnosis of lung cancer without metastasis confirmed by a negative PET/CT scan with no spinal symtoms (conducted 6 weeks previously) presented with progressive paralysis of both lower extremities and accompanying bowel and bladder symptoms. He underwent radical lobectomy of left lung under diagnosis of lung cancer without distant metastasis 6 weeks ago. Emergent MRI was performed, and MRI revealed a large intradural intramedullary mass compressing the spinal cord and extending from T12 to L1 with anterior compression of the spinal cord. Surgical decompression and tumor resection from T12 to L1 by lumbar laminectomy and durotomy were performed under a microscope. And, a diagnosis of adenocarcinoma to the spinal cord was made based on histopathologic findings. Postoperatively, the patient’s neurologic status was not significantly improved. Despite a negative PET/CT scan finding with no neurologic symptoms or pain, surgeons should not exclude the possibility of a spinal metastatic lesion with lung cancer.

Objectives
To evaluate the effectiveness of a prototype plate and cage device (PCB) in cervical spine disease.
Summary of Background
Data: Several Cage-Screw implants have recently been developed to avoid cervical platerelated complications.
Methods
A total of 34 patients with cervical disc protrusion who underwent PCB implantation between 2004 and 2007 were included in the study. There were 22 males and 12 females with a mean age of 49.9 years (range: 30 to 62 years). Odom’s Criteria were evaluated in all patients for a minimum follow-up period of 1 year (mean 24.6 months). Radiographic evaluation was performed to assess the status of fusion, intervertebral disc height, cervical lordosis and segmental kyphosis.
Results
In general, there were 20 excellent cases, 10 good cases and 4 fair cases according to Odom’s Criteria. In terms of radiological results, the height of intervertebral disc space was measured three different times, as follows: pre-operation, mean 6.07 mm; post-operation, mean 9.52 mm; last follow-up, mean 8.74 mm. No patients showed segmental instability on flexion-extension view at the last follow-up appointment. There were no cases of screw back out or device failure and no donor site morbidity.
Conclusion
PCB implant for degenerative cervical disease may restore intervertebral disc space and lordotic angle of the cervical spine without significant complications.

Summary of Background Data
Recently, minimal invasive spine surgery has been used and spine surgeons are prone to the radiation exposures. Objectives: To determine the radiologic hazard to the spine surgeon.
Methods
We searched the PUBMED, MEDLINE with Mesh term from MIS, radiation exposure.
Results
We reviewed the radiation exposure in different disease and surgery. There exist significant dose of radiation exposures in MIS Discectomy, MIS or open pedicle screw fixation, and kyphoplasty.
Conclusion
Surgeons should aware of the radiation exposure of the spine surgery and should do efforts on minimize it.