Discectomy or fusion have been a gold standard of the treatment for discogenic back pain. Since mid 1950s, spine surgeons have introduced the concept of arthroplasty for the management of low back pain. The current technologies are total disc replacement (TDR), posterior dynamic stabilization (PDS), interspinous process. Although many studies have reported their efficacy and safety, there are still lacking high-quality evidence. It is also not proven that these technologies are superior to spinal fusion in preventing the adjacent segment disease. Second generation TDR is newly developed technology. The current TDR could allow the motion of flexionextension and lateral bending, but it did not have the capacity to bear the axial compressive force. Second generation TDR placed the shock-absorption materials that can endure the compressive force. The current TDR was performed through the anterior approach, which is invasive and necessitates the removal of anterior longitudinal ligament. To overcome these disadvantages, TDR through lateral approach was developed. Various type of nucleus replacement technologies have been introduced with theoretical advantages over TDR such as less invasiveness, stable segmental motion and preservation of disc height. However, some of them had critical problems such as the migration and subsidence of implanted prosthesis. Total facet replacement arthroplasty was developed to overcome both the adjacent segment disease after fusion and the instability after posterior decompression. Because most of reports about total facet replacement arthroplasty are based on the results from the animal or cadaveric study, the long-term human trial is required. New technologies regarding motion preservation spinal surgery have been introduced, shifting paradigm in spinal care. Even though various attempts have been made in the field of spine surgery, the fact is that all of these attempts do not succeed due to paucity of better clinical outcomes. Thus, well designed long-term studies are required to prove their safety and efficacy, showing “superiority”, not just “no inferiority” to the traditional treatments.

Introduction
Degenerative change of the vertebral disc is known to be caused by inherited factors, aging and mechanical and environmental factors and it progresses due to the decreasing amount of proteoglycan in the vertebral disc. Resolving the imbalance between the synthesis and break down of proteoglycan is an important strategy for slowing additional degeneration and increasing regeneration of the disc. Body: To regenerate vertebral discs, many attempt have been made to get curative value such as direct injection of growth factors like BMP-2, BMP-7, IGF-1, TGF-β1, GDF-5 and FGF into the disc or transplantation of cytokine for improving the composition of proteoglycan. But these proteins have a short acting time and so repeated transplantation is necessary even if transplantation into the disc is done. So, much research has been done on genetic transplantation, which may improve certain proteins. Other trials of transplantation of nucleus pulposus cells, combinations of stem cells with scaffold and amalgamation with genetic care have also been done. But the safety of these therapies has not yet been completely established.
Conclusion
Biological therapy for degenerative disc disease has many benefits compared with the conventional therapies. Hereafter, according to additional research, the clinical indications for biological therapies are expected to increase. Clinical applications should be performed after securing enough results for establishing the safety and effectiveness of these new procedures.

Purpose
To find the factors that affecting surgical outcome after vertebroplasty and kyphoplasty in osteoporotic compression fracture.
Materials and Methods
Pre-operative, post-operative, technical, radiological factors of patients who diagnosed osteoporotic compression fracture and treated with vertebroplasty or kypholasty during from January 2008 to December 2010, were compared by outcomes that acute and chronic back pain, refracture rate and maintenance of the reduction of body height.
Results
The period of acute pain after the operation was less than 3 days in groups of trauma( p=0.0262) and hospital treatment(p=0.0113) before the operation as pre-operative factors. When it comes to technical factors, the cases of vertebroplasty(p<0.0001), injection of cement(p=0.0053), the case without leakage of cement(p=0.007) and the case being under anesthesia (p<0.005)achieved statistical significance. In the groups who got conservative treatment less than 1 week (p=0.0119) and local anesthetics(p=0.0246), refractures occurred many times. The groups of non-trauma(p=0.0105), having had more than 30% compression(p=0.0244) and the group that prescribed bisphosphonate(p=0.0286) statistical significantly maintained restoration.
Conclusion
Conservative treatment in the hospital for more than 1 week before the operation, operation being under anesthesia and intake of bisphosphonate after the operation put positive effects on the outcome of vertebroplasty and kyphoplasty.

Purpose
We planned this study to comparatively analyse several clinical results depending on the range of incision in herniated nucleus pulposus surgery.
Materials and Methods
We examined 49 cases herniated nucleus pulposus , performed laminectomy or discectomy from 2006.1 to 2007.2. Average age of patients was 44 years (19~73), male 25 cases and female 24 cases. 20 cases (9 male, 11 female) of conventional incision, and 17 cases (7 male, 10 female) of mini incision, 12 cases (9 male, 3 female) of microscopically assisted percutaneous nucleotomy (MAPN) were performed. All cases were protruded or extruded nucleus pulposus at L4-5 single level. Used VAS score to compare the pain after the operation with preop pain, checked ODI (Oswestry disability index) to compare the functional recovery of the ordinary activities, blood loss measured by total amount collected by drainage tube. Degrees of inflammation were compared by CRP of 1st, 7th, 14th day after the surgery.
Results
Conventional incision (Group I) took average 71 minutes of operation time, degree of pain relief was 7.8→3.2, average ODI was 61%, average blood loss was 69 ml and average change in CRP was 2.5→.2.2→2.0. In mini incision (Group II), 55 minutes, 7.3→2.47, 44%, 45 ml, 2.0→1.7→0.3 and , in cases with MAPN (Group III), 71 minutes, 7.1→2.41, 48%, 19 ml, 1.6→1.1→0.4. Operation time was similar on group I and group III and took shorter on group II. Amount of pain relief showed significant change in group II and group III, indicating that these were much greater than group I. ODI was delayed in group I. Average blood loss decreased significantly in group III. CRP level increased on first day after the operation, group II and group III showed more decrease level of CRP comparing to group I as time flows.
Conclusion
By comparing 3 groups, group III and group II were of better result in average ODI a, blood loss and CRP change. But, MAPN has long learning curve and longer operation time, so we recommend mini incision method in this study.

Protecting cranially located facet joints during pedicle screw placement is one of the modifiable factors that could prevent possible adjacent level problems related with spinal fusion procedure. Placing pedicle screws percutaneously appears to be more challenging in the technical aspect than performing with traditional open technique because of its limited selecting entry point for screw placement. The authors have reported surprisingly higher incidence and risk factors of cranial facet joint violations by percutaneously placed pedicle screws. The purpose of this literature was to illustrate the surgical technique focusing on the tips to avoid cranial facet joint violation during percutaneous placement of pedicle screws.

Purpose
Anterior lumbar interbody fusion (ALIF) is widely accepted surgical technique in the treatment of lumbar degenerative disc disease, especially with foraminal stenosis. But many surgeons suspect the effectiveness of ALIF in one or multi-level lumbar degenerative disease. The aim of this study is to evaluate the effectiveness of the two-level ALIF in lumbar degenerative disease.
Materials and Methods
Included were the patients who had foraminal stenosis or spinal stenosis with segmental instability (e.g. spondylolisthesis). All patients were studied with plain radiographs and MRI before surgery and plain radiographs at 1 week, 6, 12 and 24 months after surgery. Radiographic measurements included disc height, global lumbar lordosis and existence of lateral fusion mass. To investigate the changes in lumbar global lordosis, the Cobb angle was evaluated on pre- and postoperative standing lateral radiographs from L1 superior endplate to S1 endplate. Union was defined as the presence of trabecular osseous continuity and/or less than 4° mobility between the segments on a flexion and extension radiograph. Details of blood loss, operative time, transfusions during hospitalization, hospital day, and perioperative complications were evaluated. Clinical outcomes were assessed using Visual Analogue Scale (VAS) scores for leg and back pain and Oswestry disability index (ODI) before surgery and at 6, 12 and 24 months after surgery. Paired t-test was used for statistical analysis.
Results
37 patients (10 men and 27 women; age 33-76 years, mean 61.1 years) who had undergone ALIF combined with PLF or percutaneous pedicle screw fixation (PPF) during January 2007 and January 2009 were studied retrospectively. The mean follow-up period was 34.2 months (48-25 months). The affected levels were L3-4-5 in 14 cases and L4-5-S1 in 23 cases. The average hospital days are 10.7 days, showing no difference between PLF and PPF surgery. The average operation time is 286 minutes. Blood loss was variable from 130 mL to 1200 mL (average 621.2 mL). But Blood loss during the ALIF operation was minimal. (220 mL ; range 120-540 mL). Global lumbar lordosis was improved from 29.2 to 37.8. Postoperatively all patients had relief of sciatic pain, and there were no techniqueassociated complications. Complications included sensory deficit (hypo/dysesthesia) in 4 patients, DVT in one patient, ileus in one patient and transient sympathetic symptom in 11 patients. Two patients had wound problem but were treated easily. The VAS score in leg pain was improved from 6.9 to 2.3 with statistical significance at 24 months after surgery. Also, ODI score was decreased from 30.8 to 9.2 significantly at 24 months after surgery. Radiologic evidence of solid fusion was observed in all patients on the basis of motion and screw loosening. The lateral bone mass was observed bilaterally in 26 of the 28 patients (92%). Radiologic ASD was found in 10/37(27%), but only one patient showed symptom and had minor surgery.
Conclusion
ALIF is an effective surgical strategy for the treatment of two-level lumbar degenerative disease and could be a useful alternative to posterior fusion surgery.