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.

: 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

: The pedicle screw (PS) system is widely used for spinal reconstruction. Recently, screw insertion using the cortical bone trajectory (CBT) technique has been reported to provide increased holding strength of the vertebra, even in an osteoporotic spine. CBT is also beneficial due to its low invasiveness. We have been performing hybrid reconstruction with CBT at the cranial level and PS at the caudal level based on the concept of minimal invasiveness. We applied this hybrid technique to 6 cases of degenerative spondylolisthesis. Surgery was completed with a small skin incision of around 5-6 cm, which is shorter than that of the conventional PS procedure. The mean percent slippage before surgery was 19.8% %, and this was reduced to 3.9% % after surgery and almost maintained 3 months after surgery. Furthermore, no major surgical complications were observed. Here, we introduce the minimally invasive hybrid technique of CBT-PS. Surgeons should be aware of the procedure as an option for minimally invasive lumbar spine reconstructive surgery.

No abstract

Two women aged 65 years and 78 years presented to our center with idiopathic necrosis of the talus. In both cases, imaging examinations showed collapse and sclerotic changes of the talar body caused by the necrosis. Both women underwent resection and placement of a third-generation custom-made alumina ceramic total talar prosthesis. Immobilization of the ankle in a short-leg cast for 3 weeks was followed by early rehabilitation. One year and 6 months after surgery, both women were able to walk without pain. Their Japanese Society for Surgery of the Foot ankle-hindfoot scale scores improved from 22 and 29/100 points to 90 and 95/100 points, respectively. To the best of our knowledge, the successful treatments of these two rare cases of idiopathic necrosis of the talus are among only a few reported cases of using a third-generation alumina ceramic prosthesis.