Clinical Outcomes of Interlaminar Percutaneous Endoscopic Uniportal Pars Decompression for Lumbar Spondylolysis.

BACKGROUND: To evaluate the clinical and radiological outcomes of a novel full endoscopic procedure performed via an interlaminar approach to decompress entrapped nerve roots in patients with lumbar spondylolysis. METHODS: Patients who underwent interlaminar percutaneous endoscopic pars decompression were included in this retrospective cohort study. Patients with back pain and dynamic lumbar instability were excluded from the study. Clinical parameters related to outcomes, including the Oswestry Disability Index (ODI) and visual analog scale (VAS) for leg pain, were assessed before and after surgery. The radiological outcomes, vertebral slippage percentage, and motion radiographs were evaluated preoperatively and postoperatively. RESULTS: Of the 11 patients included in the study, 5 had spondylolysis alone, 1 of whom had spondylolysis at L3-L4 and L4-L5, and 4 of whom had it at L5-S1; and 6 patients had spondylolysis in combination with spondylolisthesis, of whom 4 had involvement at L5-S1, 1 had involvement at L4-L5, and 1 had involvement at L3-L4. At a mean follow-up period of 22.64 months, 63.3% of patients achieved more than 50% improvement in ODI score and 90.91% of patients achieved more than 50% improvement in VAS score. Spondylolysis with vertebral slippage had inferior ODI improvement outcomes as compared with spondylolysis alone, but the VAS was not significantly different. No significant difference was observed on the slippage percentage observed between the pre- and postoperative periods. However, 1 patient experienced vertebral slippage after surgery, but fusion surgery was not required. CONCLUSIONS: Interlaminar percutaneous endoscopic pars decompression is a safe and successful treatment for patients with stable lumbar spondylolysis and nerve root compression. Even in situations in which vertebral slippage occurs, spinal fusion may not be the best option for all patients with lumbar spondylolysis. CLINICAL RELEVANCE: The interlaminar percutaneous endoscopic pars decompression is a safe and successful procedure for treatment of patients with stable lumbar spondylolysis and nerve root compression.

Ex vivo and in vivo characterization of cold preserved cartilage for cell transplantation.

Due to the inconvenient and invasive nature of chondrocyte transplantation, preserved cartilage has been recognized as an alternative source of chondrocytes for implantation. However, there are major concerns, in particular, the viability and quality of the chondrocytes. This study investigated the biochemistry and molecular characterization of chondrocytes isolated from preserved cartilage for purposes of transplantation. Ex vivo characterization was accomplished by storing human cartilage at either 4 or -80 °C in a preservation medium. Microscopic evaluation of the preserved cartilage was conducted after 1, 2, 3 and 6 weeks. The chondrocytes were isolated from the preserved cartilage and investigated for proliferation capacity and chondrogenic phenotype. Transplantation of chondrocytes from preserved cartilage into rabbit knees was performed for purposes of in vivo evaluation. The serum cartilage degradation biomarker (WF6 epitopes) was evaluated during the transplantation procedure. Human cartilage preserved for 1 week in a 10 % DMSO chondrogenic medium at 4 °C gave the highest chondrocyte viability. The isolated chondrocytes showed a high proliferative capacity and retained chondrogenic gene expression. Microscopic assessment of the implanted rabbit knees showed tissue regeneration and integration with the host cartilage. A decreased level of the serum biomarker after transplantation was evidence of in vivo repair by the implanted chondrocytes. These results suggest that cartilage preservation for 1 week in a 10 % DMSO chondrogenic medium at 4 °C can maintain proliferation capacity and the chondrogenic phenotype of human chondrocytes. These results can potentially be applied to in vivo allogeneic chondrocyte transplantation. Allogeneic chondrocytes from preserved cartilage would be expected to maintain their chondrogenic phenotype and to result in a high rate of success in transplanted grafts.

Survival rate and prognostic factors of conventional osteosarcoma in Northern Thailand: A series from Chiang Mai University Hospital.

BACKGROUND: Osteosarcoma is a common and aggressive primary malignant bone tumor occurring in children and adolescents. It is one of the most aggressive human cancers and the most common cause of cancer-associated limb loss. As treatment in Thailand has produced a lower survival rate than in developed countries; therefore, this study identified survival rate and the poor prognostic factors of osteosarcoma in Northern Thailand. METHODS: The retrospective cases of osteosarcoma, diagnosis between 1 January 1996 and 31 December 2013, were evaluated. Five and ten year overall survival rates were analyzed using time-to-event analysis. Potential prognostic factors were identified by multivariate regression analysis. RESULTS: There were 208 newly diagnosed osteosarcomas during that period, and 144 cases met the criteria for analysis. The majority of the osteosarcoma cases (78.5%) were aged 0-24 years. The overall 5- and 10-year survival rates were 37.9% and 33.6%, respectively. Presence of metastasis at initial examination, delayed and against treatment co-operation, and axial skeletal location were identified as independent prognostic factors for survival, with hazard ratios of 4.3, 2.5 and 3.8, and 3.1, respectively. CONCLUSIONS: This osteosarcoma cohort had a relatively poor overall survival rate. The prognostic factors identified would play a critical role in modifying survival rates of osteosarcoma patients; as rapid disease recognition, a better treatment counselling, as well as improving of chemotherapeutic regimens were found to be important in improving the overall survival rate in Thailand.