Search

Abstract Background Mesenchymal stem cells (MSCs) are known to have different differentiation potential depending on the tissue of origin. Dedifferentiated fat cells (DFATs) are MSC-like multipotent cells that can be prepared from mature adipocytes by ceiling culture method. It is still unknown whether DFATs derived from adipocytes in different tissue showed different phenotype and functional properties. In the present study, we prepared bone marrow (BM)-derived DFATs (BM-DFATs), BM-MSCs, subcutaneous (SC) adipose tissue-derived DFATs (SC-DFATs), and adipose tissue-derived stem cells (ASCs) from donor-matched tissue samples. Then, we compared their phenotypes and multilineage differentiation potential in vitro. We also evaluated in vivo bone regeneration ability of these cells using a mouse femoral fracture model. Methods BM-DFATs, SC-DFATs, BM-MSCs, and ASCs were prepared from tissue samples of knee osteoarthritis patients who received total knee arthroplasty. Cell surface antigens, gene expression profile, and in vitro differentiation capacity of these cells were determined. In vivo bone regenerative ability of these cells was evaluated by micro-computed tomography imaging at 28 days after local injection of the cells with peptide hydrogel (PHG) in the femoral fracture model in severe combined immunodeficiency mice. Results BM-DFATs were successfully generated at similar efficiency as SC-DFATs. Cell surface antigen and gene expression profiles of BM-DFATs were similar to those of BM-MSCs, whereas these profiles of SC-DFATs were similar to those of ASCs. In vitro differentiation analysis revealed that BM-DFATs and BM-MSCs had higher differentiation tendency toward osteoblasts and lower differentiation tendency toward adipocytes compared to SC-DFATs and ASCs. Transplantation of BM-DFATs and BM-MSCs with PHG enhanced bone mineral density at the injection sites compared to PHG alone in the mouse femoral fracture model. Conclusions We showed that phenotypic characteristics of BM-DFATs were similar to those of BM-MSCs. BM-DFATs exhibited higher osteogenic differentiation potential and bone regenerative ability compared to SC-DFATs and ASCs. These results suggest that BM-DFATs may be suitable sources of cell-based therapies for patients with nonunion bone fracture.

Abstract Background The popliteus tendon (PT) or lateral collateral ligament (LCL) stabilizes the postero-lateral aspects of the knees. When surgeons perform total knee arthroplasty (TKA), PT and LCL iatrogenic injuries are a risk because the femoral attachments are relatively close to the femoral bone resection area. The purpose of this study was to evaluate the distance between the PT or LCL footprint and the TKA implant using a 3D template system and to evaluate any significant differences according to the implant model. Methods Eighteen non-paired formalin fixed cadaveric lower limbs were used (average age: 80.3). Whole length lower limbs were resected from the pelvis. All the surrounding soft tissue except the PT, knee ligaments and meniscus were removed from the limb. Careful dissection of the PT and LCL was performed, and the femoral footprints were detected. Each footprint periphery was marked with a 1.5 mm K-wire. Computed tomography (CT) scanning of the whole lower limb was then performed. The CT data was analyzed with a 3D template system. This simulation models for TKA were the Journey II BCS and the Persona PS. The area of each footprint, and the length between the most distal and posterior point of the lateral femoral condyle and the edge of each footprint were measured. Matching the implant model to the CT image of the femur, the shortest length between each footprint and the bone resection area were calculated. Results PT and LCL footprint were detected in all knees. The area of the PT and LCL footprints was 38.7 ± 17.7 mm2 and 58.0 ± 24.6 mm2, respectively. The length between the most distal and posterior point of the lateral femoral condyle and the edge of the PT footprint was 10.3 ± 2.4 mm and 14.2 ± 2.8 mm, respectively. The length between most distal and most posterior point of the lateral femoral condyle and the edge of the LCL footprint was 16.3 ± 2.3 mm and 15.5 ± 3.3 mm, respectively. Under TKA simulation, the shortest length between the PT footprint and the femoral bone resection area for the Journey II BCS and the Persona PS was 4.3 ± 2.5 mm and 3.2 ± 2.9 mm, respectively. The shortest length between the LCL footprint and the femoral bone resection area for the Journey II BCS and the Persona PS was 7.2 ± 2.3 mm and 5.6 ± 2.1 mm, respectively. The PT attachment was damaged by the bone resection of the Journey II BCS and the Persona PS TKA in 3 and 9 knees, respectively. Conclusion The PT and LCL femoral attachments existed close to the femoral bone resection area of the TKA. To prevent postero-lateral instability in TKA, careful attention is needed to avoid damage to the PT and LCL during surgical procedures.

Abstract Background Therapeutic intervention has recently been actively performed for metastatic spine tumor even though spinal cord paralysis is not clearly observed, but there has been no report in which the degree of spinal cord compression by tumor was taken into consideration for the paralysis-preventing effect of treatment. Thus, we investigated the neurological outcome after treatment of patients with spinal cord compression in a state of impending paralysis. Methods A retrospective cohort study. The subjects were 88 patients with epidural spinal cord compression (ESCC) scale 1b or severer compression with American Spinal Injury Association (ASIA) E spinal metastasis. The neurological outcome after the therapeutic intervention was investigated at regular intervals until death. The therapeutic intervention was posterior decompression and stabilization in 18 patients, stabilization without posterior decompression in 15, and radiotherapy in 55 patients (3 groups). Results The ASIA aggravation group was comprised of 15 patients, and the severity of paralysis was ASIA A in 3, B in 3, C in 6, and D in 3. Paralysis appeared in 16.7% in the posterior decompression and stabilization group, 13.3% in the posterior stabilization without decompression group, and 18.8% in the radiotherapy group. In the transverse view, the incidence was high in cases with advancement to the intervertebral foramen and circumferential-type advancement, and paralysis developed in more than 20% of ESCC 1c or severer cases. Factors influencing neurological aggravation were investigated, but there was no significant factor. Conclusion In ESCC 1b or severer cases with ASIA E spinal metastasis, paralysis aggravated after therapeutic intervention in 16.7% in the posterior decompression and stabilization group, 13.3% in the stabilization without decompression group, and 16.7% in the radiotherapy group. There was no significant factor influencing the development of paralysis.

Abstract Background There have been only a few reports of subsequent postoperative vertebral fracture following posterior spinal instrumentation fusion, especially in elderly female patients. This study attempted to evaluate the long-term prevalence of subsequent postoperative vertebral fracture in female patients aged 70 years and older who underwent spine decompression and fusion surgery with pedicle screw fixation. Methods We retrospectively reviewed prospectively collected data from 125 patients who met our inclusion and exclusion criteria. Patients were divided into 2 groups according to age: patients aged 70 years and older (Group A) and patients aged under 70 years of age (Group B). We evaluated incidence of subsequent postoperative vertebral fractures, type and timing of vertebral fractures, preoperative bone mineral density (BMD), preoperative diagnosis, surgical procedure, number of levels fused, extension of fusion to the lumbosacral junction, and presence of a transverse fixator. Results Baseline characteristics excluding patients’ age were not statistically different between the two groups. Preoperative BMD of Group A was an average 81.7% of the young adult mean (YAM) value and that of Group B was an average 85.1% YAM value. Subsequent postoperative vertebral fractures occurred in 22 (41.5%) of 53 in Group A. On the other hand, fracture occurred in 17 (23.6%) of 72 in Group B. There were significant differences between the groups (p = 0.02). The odds ratio for subsequent vertebral fracture was 2.4 (95% confidence interval: 1.1–5.2) in favor of Group A. Survival analysis showed that the rate of subsequent vertebral fracture was significantly higher in Group A (log-rank test, P = 0.007). Conclusions The incidence of subsequent vertebral fracture in patients aged 70 years and older was significantly higher than in patients aged under 70 years of age. In the case of pedicle screw fixation in elderly female patients, it is necessary to note the high risk of subsequent vertebral fracture despite short or non-rigid fusion. Vertebral fracture after posterior fusion surgery even for degenerative lumbar pathology could occur in more than one-third of female patients aged 70 years and older.

Abstract Background The Magerl and Goel-Harms techniques have been reported to produce excellent treatment outcomes in cases of atlantoaxial subluxation, but they also carry a risk of vertebral artery injuries. In order to completely prevent such injuries, we developed a surgical procedure, involving bone grafting between the C1 posterior arch and C2 lamina with clamp- or hook-and-rod-based fixation combined with the insertion of an interference screw into the posterior atlantoaxial joint. Methods This was a retrospective single-center study. The subjects were 58 patients in whom atlantoaxial subluxation was treated with the abovementioned procedure after 1995 (33 patients with rheumatoid arthritis (RA group) and 25 patients without rheumatoid arthritis (non-RA group)). The clinical outcomes and imaging findings of anterior subluxation at ≥ 2 years after surgery were compared between the RA and non-RA groups. Results No vertebral artery injuries occurred during surgery. Seven and two patients died during the follow-up period in the RA and non-RA groups, respectively, but none of these deaths were associated with surgery. At ≥ 2 years after surgery, the visual analogue scale score, Japanese Orthopaedic Association score, and Ranawat classification had significantly improved in both groups (p

Abstract Background Proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery in elderly patients is markedly influenced by osteoporosis causing additional vertebral fracture and loosening of pedicle screws (PS). This study aimed to investigate the association between mean bone density represented in Hounsfield units (HU) on spinal computed tomography (CT) and revision surgery for PJK or postoperative additional vertebral fracture following ASD surgery in elderly patients. Methods The subjects were 54 ASD patients aged 65 years or older who were treated with correction and fusion surgery of four or more levels and could be followed for 2 years or longer. Bone density was measured before surgery using lumbar dual-energy X-ray absorptiometry (DXA) and spinal CT in all patients. The patients were divided into group A (n = 14) in which revision surgery was required for PJK or additional vertebral fracture and group B (n = 40) in which revision surgery was not required. We retrospectively investigated incidences of PJK, additional vertebral fracture, and PS loosening, perioperative parameters, radiographic parameters before and after surgery, and osteoporosis treatment administration rate. Results No significant difference was noted in young adult mean (YAM) on DXA between groups A and B, respectively (P = 0.62), but the mean bone densities represented in HU of the T8 (P = 0.002) and T9 (P = 0.01) vertebral bodies on spinal CT were significantly lower in group A, whereas those of the L4 (P = 0.002) and L5 (P = 0.01) vertebral bodies were significantly higher in group A. The incidence of PJK was not significantly different (P = 0.07), but the incidence of additional vertebral fracture was significantly higher in group A (P

Abstract Background Recently, molecule-targeting and bone-modifying agents have improved the treatment outcomes of lung cancer-derived metastatic spine tumors. Therefore, the prognostic factors for such tumors were examined, and novel scoring systems for predicting the life expectancy of patients with such tumors were proposed. Methods In 207 patients with lung cancer-derived metastatic spine tumors (surgery 49; conservative therapy 158), we retrospectively examined the factors that influenced the post-treatment survival time (age, sex, the affected site, pathology, general condition, the number of extraspinal bone metastases, the number of spinal metastases, the presence/absence of major internal organ metastasis, paralysis state, the total Tokuhashi score, the serum alkaline phosphatase level, the serum carcinoembryonic antigen level, molecule-targeting drug treatment, and bone-modifying agent treatment). Based on the results, we devised novel scoring systems for predicting the prognosis of such patients. Results Univariate analyses showed that the pathology of the primary lung tumor, the patient’s general condition and paralysis state, and the presence/absence of molecule-targeting drug treatment significantly influenced survival. We performed a Cox regression analysis of these four factors and developed criteria for a novel scoring system based on the patient’s general condition and paralysis state, which exhibited significance in the regression analysis. A retrospective review indicated that the consistency rate between predicted life expectancy and actual survival was 67.3%. When criteria based on the four factors that exhibited significance in the univariate analyses were adopted, the consistency rate was 76.2%. Conclusion The patient’s general condition and paralysis state, the pathology of the primary lung tumor, and molecule-targeting drug treatment influenced survival among patients with lung cancer-derived metastatic spine tumors. Novel scoring systems based on these four factors were proposed.

Abstract Background Posterior decompression and stabilization plays significant roles in palliative surgery for metastatic spinal tumor. However, the indication for addition of posterior decompression have not been examined. The purpose of this study was to investigate a retrospective cohort of outcomes of metastatic spinal tumor treated with minimally invasive spine stabilization (MISt) with or without posterior decompression. Methods The subjects were 40 patients who underwent MISt using percutaneous pedicle screws for metastatic spinal tumor, including 20 patients treated with stabilization alone (group A) and 20 patients with added posterior decompression (group B). We analyzed baseline characteristics, postoperative survival time, and perioperative factors such as neurological outcomes, Barthel Index, VAS, and rate of discharge to home. Results The mean ages were 70 and 66 years old (P = 0.06), the mean revised Tokuhashi scores were 7.2 and 5.8 (P = 0.1), the mean spinal instability neoplastic scores (SINS) were 10.5 and 9.0 (P = 0.04), and the mean Barthel Index for ADL were 65.5 and 41.0 (P = 0.06) in groups A and B, respectively. The median postoperative survival time did not differ significantly between groups A and B (12.0 vs. 6.0 months, P = 0.09). Patients in group A had a significantly shorter operation time (166 vs. 232 min, P = 0.004) and lower intraoperative blood loss (120 vs. 478 mL, P

Abstract Background Surgeries performed for metastatic spinal tumor are mostly palliative and are controversial for patients with short life expectancy. We investigated whether palliative posterior spinal stabilization surgery with postoperative multidisciplinary therapy results in improvement of life prognosis and activities of daily living (ADL) in patients with metastatic spinal tumor. Methods The subjects were 55 patients who underwent palliative posterior-only instrumentation surgery for metastatic spinal tumor at our hospital between 2012 and 2015. Postoperative survival, early paralysis improvement, ADL improvement, and rate of discharge to home were examined. Results The patients included 37 males and 18 females, and the mean age at the time of surgery was 66.8 years old. The mean Tokuhashi score was 7.1, the mean spinal instability neoplastic score (SINS) was 9.4, and the epidural spinal cord compression scale (ESCCS) was grade 3 in 20 patients (36.3%). The mean Barthel index for ADL was 48.7. The median postoperative survival time determined using the Kaplan-Meier method was 12.0 months (95% confidence interval 2.4–21.5). Regarding improvement of paralysis, the modified Frankel scale was improved by one grade or more or grade E was maintained in 35 patients (63.6%), whereas paralysis aggravated in 2 (3.6%). In surgery, conventional posterior decompression and fixation were applied in 31 patients (56.3%), and minimally invasive spine stabilization was applied in 24 (43.6%). Postoperative chemotherapy was performed in 31 patients (56.3%), radiotherapy was used in 38 (69.0%), and a bone-modifying agent was administered in 39 (70.2%). Regarding ADL, the mean Barthel index improved from 48.5 before surgery to 74.5 after surgery. Thirty-seven patients (67.2%) were discharged to home. Conclusions ADL improved and allowed discharge to home, and postoperative adjuvant therapy could be administered at a high rate in patients who received palliative posterior spinal stabilization surgery. Survival time extended beyond the preoperative life expectancy in many patients. Patients with a metastatic spinal tumor have short life expectancy and paralysis caused by spinal instability and spinal cord compression. However, multidisciplinary therapy including palliative posterior spinal stabilization surgery with reduced invasiveness and postoperative adjuvant therapy are effective in these patients.