Purpose
To analyze the serial changes of the lumbar sagittal alignment from preop. to final follow-up and to evaluate the role of the posterior spinal instrumentation, especially, short level fusion in correction and maintenance of the lumbar sagittal alignment in degenerative lumbar disease.
Materials and Methods
Various lumbar sagittal profiles such as lumbar lordosis(LL), lordosis above, within and below instrumentation(LAI, LWI, LBI), horizontal vertebra and sacral inclination were serially measured in 54 patients whose radiographs at preop., intraop., immed. postop. postop. 2wks and final follow up(>1 yr) were completely equipped.
Results
Intraop. posture, instrumentation itself and interbody fusion could not increase the LL and LWI sufficiently irrespective of the length of fixation. LWI was decreased compared with preop. values irrespective of length of fixation, while interbody fusion has a great role in maintaining the LWI. Loss of LWI was overcompensated at the segments above instrumentation in 1 or 2 levels fixation while compensation has not occurred in longer fixations.
Conclusions
The longer the fixation, the more correction could be obtained. However, maintenance of this correction is more difficult in longer fixations. Prudent consideration should be taken in restoring sufficient lumbar lordosis and maintenance for favorable long term results.

Spinal cord tumors are uncommon lesions and can lead to significant neurologic morbidity and mortality. The classification of spinal cord tumors is based on their location as intradural intramedullary, intradural extramedullary, and extradural. Ependymomas are more common among intradural intramedullary tumors, and can often be surgically resected, whereas, astrocytomas infiltrate the spinal cord and show unclear marginality between the tumor and spinal cord. Complete surgical resection is obtained rarely. Intradural extramedullary tumors include schwannomas, neurofibromas, and meningiomas. These types are relatively curable with surgical resection than intradural intramedullary tumors. Radiotherapy is applied for malignant variants and recurrent tumors, whereas chemotherapy is usually recommended for recurrent lesions which are not effective with surgery or radiotherapy. Preoperative neurological status, histologic grade of the tumor, and the extent of surgical resection result in different outcomes.

Purpose
of study: The purpose of this study is to understand the biomechanics of interspinous devices in lumbar spinal surgery and to review the effectiveness of the devices for lumbar spinal stenosis through recent related articles.
Materials and Methods
Medical databases were searched for the key words of interspinous device and lumbar spinal stenosis using PubMed from 2010 to the present.
Results
Several studies have shown sustained symptomatic improvements after interspinous device insertion. However, most of the prospective, randomized, double-blinded studies have shown that it is not superior to conventional laminectomy from a statistical perspective. Furthermore, interspinous device insertion has been shown to have a higher reoperation rate and to be less cost effective.
Conclusions
A large prospective cohort study with a longer follow-up period comparing decompressive surgery alone versus interspinous device insertion for the treatment of lumbar spinal stenosis is needed to conclusively determine whether the interspinous device is beneficial.

Purpose
Total en bloc spondylectomy (TES) is one of curative surgical methods used for solitary spinal tumors, if indicated. However, TES is a complex technique and prudent preparation is mandatory. However, elective TES is not always possible for patients with neurological and mechanical spinal instability. In such situations, percutaneous pedicle screw fixation, with the purpose of stabilizing the spine and gaining time before TES, may be used.
Methods
The first patient was a 29-year-old female who visited the emergency room (ER) due to progressive paraparesis (motor grade III/V) and back pain. Magnetic resonance imaging (MRI) showed compression of the spinal cord by a tumor and a collapsed L1 body. The second patient was a 23-year-old female who came to the ER with severe back pain. MRI revealed compression of the spinal cord by a collapsed T11 vertebral body and a tumor. In both cases, neurological and mechanical instabilities were caused by a primary vertebral tumor. For both patients, TES was an optimal surgical technique, but TES was not possible on an emergency basis.
Results
In both patients, percutaneous pedicle screw fixation, distraction, and biopsy were performed on an emergency basis. Subsequently, weakness and/or pain improved in both patients. Elective TES operations were successfully performed 3 weeks or 1 month later.
Conclusions
If TES is indicated, but preparation time is insufficient, tentative spinal stabilization with a percutaneous technique may be utilized before TES. However, considering the need for additional surgery, skin incision, and cost, this surgical strategy should be selectively applied.

Introducing a 61-year old woman who was suffering from complicated traumatic thoracolumbar spine fractures, we contemplated the appropriate management algorithm. The Thoracolumbar Injury Classification and Severity score (TLICS) system is the latest and widely used scoring system by spine surgeons for thoracolumbar injuries (TLI). The originator of the system claims for easy application, high reproducibility, and direct link to a clinical decision-making algorithm. However, because of its simple and narrow boundaries, there are many limitations to apply the system in complicated situations. Besides, a fair number of TLI are caused by high velocity traumas, which mostly lead to complicated fractures and other medical conditions. For these reasons, practically, we also consider traditional and former concepts of TLI classifications. Furthermore, new algorithm should be suggested which includes not only the spine morphology and neurological manifestation but also comprehensive medical considerations of the patient.