Purpose
To evaluate and analyze the clinical results of lumbar microdiscectomy using minimally invasive tubular retractor between recurrence and non-recurrence group, and to assess the merits of minimally invasive spinal surgery. Overview of Literature: No large registry study has so far investigated the clinical results of lumbar microdiscectomy using minimally invasive tubular retractor.
Methods
From July 2003 to April 2011 we retrospectively studied a consecutive series of 156 patients who underwent lumbar microdiscectomy using minimally invasive tubular retractor. The following data were collected: clinical outcomes, operative time, intraoperative blood loss, recurrence, and complications. The clinical outcomes were measured using a visual analog scale (VAS) and assessed by the modified MacNab criteria.
Results
Minimally invasive tubular microdiscectomy was performed in 156 patients. The clinical outcomes assessed by MacNab criteria were excellent in 63 patients (40%), good in 71 patients (45%). VAS scores of low-back pain decreased from a mean of 6.7 prior to surgery to 2.5 after surgery, and that of leg pain decreased from 7.2 to 2.1. The average operative time was 68 minutes (range, 25 to 180 minutes). The average blood loss was 42 mL (range, 0 to 500 mL). None of the patients needed blood replacement. One patient had wound infection problem but there was no dural tear case. Twenty-two patients had recurrence. Average time to recurrence was about 42 months. Seventeen cases recurred at the same level and five cases recurred at the adjacent level. Eleven cases in 22 patients with recurrence were contained disc type and the others were non-contained disc type. Eighteen cases in 22 patients with recurrence were paracentral disc herniation type and the others were far lateral type. Average body mass index (BMI) of recurrence cases was 24.7 (range, 17.5 to 31.3) and that of non-recurrence cases was 24.5 (range, 16.3 to 39.2).
Conclusions
Lumbar microdiscectomy using tubular retractor can offer a useful modality for the treatment of lumbar herniated disc with the merits of minimally invasive spinal surgery. Further randomized, prospective investigations are needed to fully evaluate the impact of this technique.

Objectives
The primary surgical goals when treating a spinal metastasis are usually pain relief and preservation of ambulatory function. Minimally invasive techniques have become popular, being associated with less morbidity and mortality than conventional open surgeries.
Materials and Methods
Between April 2012 and September 2016, 15 consecutive patients underwent percutaneous pedicle screw fixation (PPSF) to treat spinal metastases. We retrospectively analyzed prospectively collected data, including visual analog scale (VAS) pain scores, Frankel scale scores, and complications.
Results
Fifteen patients (8 males, 7 females; mean age 61 years) underwent surgery under general anesthesia. PPSF was performed on all patients, and two with poor bone quality underwent cement augmentation of the manipulated vertebra(e) just prior to pedicle screw insertion. Seven patients underwent fixation plus distraction (indirect decompression via ligamentotaxis) and two laminectomies (direct decompression) of the spinal cord. Two patients developed screw pullout requiring revision surgery. One patient died 7 days after surgery from liver cirrhosis and sepsis. All patients reported that pain was reduced after surgery. After surgery, 12 patients regained ambulatory capacity. Nine patients died during follow-up; the mean overall survival time was 14.1 months.
Conclusions
PPSF is a safe and minimally invasive palliative surgery option for patients with spinal metastases.

Recently, favorable results of minimally invasive spinal surgery have been reported in comparison to the open decompression or fusion surgery. Biportal endoscopic spine surgery (BESS) has several benefits and Indications for BESS are nearly identical to those for general open spinal surgery. However, it remains a challenging procedure even for an experienced endoscopic surgeon. because it takes a a long operation time while early learning period. If the operation time is prolonged, the advantages of endoscopic surgery are reduced and the incidence of complications can be increased. Therefore, we will investigate the factors affecting the operation time and how to minimize it before and during operation.

Among the complex causes of chronic low back pain, suboptimal injury of ligament in the lumbosacral spine is common. Injured ligaments can become a primary pain source and raise secondary pain with referred pain pattern. Due to the low blood supply to the ligaments, ligaments are notoriously poor healer. In order to compensate the poor healing of ligament, prolotherapy has been introduced and used for more 60 years. To date, no definite recommendations have not been made based on literature available. However, if conventional treatment modalities have failed in patient with chronic back pain in lumbosacral spine, prolotherapy targeted on ligaments around lumbosacral spine should be considered in appropriate patients.