The correlation between the high stresses in the pedicle and the corresponding HSC suggest that signal changes in MRI could be used as an indicator for early diagnosis of spondylolysis. The HSC of the pedicle provided useful information to diagnose early stage spondylolysis. Furthermore, the HSC may be a good indicator as to whether a bony union will result from conservative treatment.

Minimally invasive percutaneous endoscopic discectomy (PED) with a transforaminal approach under local anesthesia was started in the late 20th century. As the procedure requires a skin incision of only 8 mm, it is the least invasive disc surgery procedure at present, and owing to advances in instruments and optics, the use of this technique has gradually spread. In Japan, Dr. Dezawa from Teikyo University Mizonokuchi Hospital introduced this technique in 2003. Thanks to his efforts, the number of surgeons who can perform PED has increased, although the number of active PED surgeons is still only around 20. The first author (K.S.) started PED in 2010. In this review article, we explain the state-of-the-art PED transforaminal technique for minimally invasive disc surgery and present three successful cases.

2.

: The minimally invasive percutaneous endoscopic discectomy (PED) as the postero-lateral approach with the local anesthesia was started in the late 20th century. The procedure only requires 8 mm of skin incision ; thus, it is the least invasive disc surgery presently. The surgery related complications were reviewed in the initial 100 cases from the single surgeon (K.S., first author). Two cases showed exiting nerve irritation, and complained of leg paresthetic pain for 6 to 12 weeks after the surgery (2.0% %). The symptoms got better with medicines. One showed post-surgical epidural hematoma, and required surgical removal of the mass (1.0% %). Two cases complained neck pain during surgery (2.0% %). Surgeons would be aware of the specific complications for the postero-lateral approach of PED procedure. J. Med. Invest. 61 : 264-269, August, 2014

We conducted population-based association tests for the four selected SNPs (rs2240340/padi4_94, rs7528684/fcrl3_3, rs3792876/slc2F2 and rs2268277/ runx1) previously reported to be associated with rheumatoid arthritis (RA). The study population consisted of 950 unrelated Japanese subjects with RA and 507 controls, none of whom had previously been tested for these variants. Only the SNP rs2240340/padi4_94 was modestly associated with RA [allele odds ratio (OR) 1.22, 95% confidence interval (CI) 1.04-1.43, P = 0.012]. The most significant association effect was found for genotype contrast between minor and major allele homozygotes (OR 1.53, 95% CI 1.10-2.12, P = 0.010). No other SNPs showed a statistically significant association with RA in our population. Meta-analysis of published studies and our new data confirmed a highly significant association between PADI4 gene SNPs and increased risk of RA in East Asian populations (allele fixed-effects summary OR 1.31, 95% CI 1.22-1.41, P \ 0.0001). We found some evidence for an association of either rs7528684/fcrl3_3 or rs3792876/slc2F2 with RA; however, because the magnitudes of effects were apparently much weaker than those reported in the initial positive reports, and there were substantial levels of inter-study OR heterogeneity, we concluded that additional studies are needed to fully understand the present results.