Purpose
Higher viscous cement can be injected through larger-diametered tubes with lower pressure. The lower the cement modulus is, the less the stress-transfer would be. The lower-pressure percutaneous vertebroplasty with blood-mixed cement(LP-PVP^blood ) was devised to overcome technical problems in conventional percutaneous vertebroplasty(C-PVP). We would like to prove the validity of technical modifications to increase viscosity of cement being injected and reduce final modulus of cement.
Methods
Nineteen C-PVPs, 51 kyphoplasty (KPs), 23 LP-PVPs and 70 LP-PVP^blood s were analyzed in radiologic point of view. The successful cases with sufficient cement volume(≥ 5ml) were also analyzed as a subgroup.
Results
Asymptomatic cement leakage(CL) showed a similar tendency in LP-PV^blood (17.1%) compared to other groups(21.1~27.5%, p=0.514), even though the injected cement volume in LP-PVP^blood (6.9ml) was much more than that of C-PVP(3.5ml, p=0.000). Vertebral height restoration(VHR) was significantly higher(11.7%) than C-PVP(4.7%, p=0.024). Vertebral body subsidence(VS) was less in KP(1.1%) than others(2.1~5.9%, p=0.000). But, adjacent vertebral compression fractures(VCFs) happened more frequently in KP(15.7%) than others (0~5.3%, p=0.001). In subgroup analysis, the rates of successful cases were significantly higher in LP-PVP^blood (85.7%) than in C-PVP(5.3%, p=0.000). CLs and VHRs showed no significant differences. VS was significantly less in KP(1.0%, p=0.000) but adjacent VCF developed more frequently in KP(21.1%) than LP-PVP^blood (0%, p=0.001).
Conclusions
The LP-PVP^blood which stands for larger diameter tubes for injecting sufficient volume of higher viscous cement and more interdigitation by omitting balloon and lower modulus blood-mixed cement was appraised to reduce risk of cement leakage than C-PVP and decrease stress transfer to adjacent vertebrae than KP.

Purpose
To say the medical and social issues as to the percutaneous epidural adhesiolysis.
Materials and Methods
Chronological alteration of the performance was reviewed. Its superiority to the other conventional interventional therapy was reviewed. It was investigated whether the effect of its instruments and drugs coincided with its purpose from the medical and social points of view.
Results
Its fundamental purpose is adhesiolysis. The evidence, however, that adhesion is related with spinal symptoms was unclear. It seems absurd to recognize the effects of instruments and drugs before verification of symptom contribution of adhesion. According to the literatures, there was no additional benefit in using hyaluronidase, rather it brought about complications such as anaphylaxis. Hypertonic saline had serious side effects even though it improved the results. The effect of steroid did not outrun that of placebo. Local anesthetics reduced pain, but it had nothing to do with adhesion. The overstatement of its effect gave rise to confusion in therapeutic algorithm in spinal diseases. Also the suffix ‘-plasty’ which has the meaning of forming surgically is inappropriate for the procedure of some epidural injection.
Conclusion
It is necessary to clarify the purpose and action mechanism of percutaneous epidural neuroplasty and establish appropriate indications. Then the misnomer should be corrected on the bases of its possible applications.

Purpose
To verify the validity of a pedicle screw based posterior dynamic stabilization(PDS).
Materials and Methods
At first, theoretical evidences were reviewed and presented the objections against PDS. The answers were investigated by reviewing the development concepts and clinical evidences of each device.
Results
There is no PDS which has been approved as a dynamic stabilizer by US FDA yet. Dynesis^® and Isobar TTL^® were approved as a fusion adjunct. AccFlex^® and CD-Horizon Legacy PEEK rod^® were approved as a single level posterior lumbar interbody fusion adjunct. Dynesys^® is undergoing an FDA IDE study as a non-fusion dynamic stabilizer. Patient’s symptoms were improved, however, there were scarce controlled studies with simple decompression or fusion surgeries. Furthermore quantitative comparison of improvement was impossible because the subjects were not homogenous. Adjacent segment degeneration was not prevented. Stabilized segments showed further degeneration and there wasn’t a case which showed regeneration of disc. Most of segments were fused or became more stable than physiologic motion and allowance of the PDS. Device failure was reported as 5-21%, however most cases were asymptomatic.
Conclusion
In the light of current evidences, PDS is considered not to prevent the problems which were engendered by fusion surgeries. It is not convincible that PDS has a niche between decompression and fusion surgeries.