Fatigue wear test comparing vitamin-E-blended crosslinked polyethylene and conventional polyethylene in a Posterior Dynamic Stabilization System of the spine in the laboratory.

BACKGROUND: Although artificial joints using polyethylene have been developed for various joints, the development of Posterior Dynamic Stabilization system of the spine using polyethylene has proceeded at a much slower pace. There are no studies which compare the abrasion resistance of vitamin-E-blended crosslinked polyethylene (VE) and conventional polyethylene (Virgin) in the spinal region. The purpose of this study was to compare the wear resistance of VE and Virgin in a Posterior Dynamic Stabilization System of the spine. METHODS: Posterior Dynamic Stabilization System of the spine uses a polyethylene ball as a sliding surface. A fatigue wear test was repeated up to 1 million cycles at a speed of ±5°, 1 Hz while the rod was being pulled at a load of 50 N. Balls were compared using VE and Virgin in 6 samples each. Ti-6AL-4 V (Ti 64) and Co-Cr-Mo (CoCr) rods were used. Abrasion loss and shape change of the polyethylene balls were compared. RESULTS: When Ti 64 was used as the rod, the average wear amount was -0.01 mg (0.02 mg, 0.01 mg, -0.06 mg) for VE, and 0.23 mg (0.18 mg, 0.13 mg, 0.38 mg) for Virgin. When CoCr was used as the rod, the average wear amount was 0.42 mg (0.71 mg, -0.06 mg, 0.61 mg) for VE, and 0.73 mg (0.72 mg, 0.70 mg, 0.76 mg) for Virgin. Most polyethylene samples showed indentations of 0.1 m or less at the contact point with the set screw. In the combination of Virgin and CoCr, a white patch was observed on the inner side of the polyethylene samples, with a maximum depression of 0.1 mm. CONCLUSIONS: A fatigue wear test showed VE to be more efficient in abrasion resistance than Virgin in a Posterior Dynamic Stabilization System of the spine in the laboratory.

Predictors for quality of life improvement after acute osteoporotic vertebral fracture: results of post hoc analysis of a prospective randomized study.

PURPOSE: No study has investigated the clinical and radiographic risk factors for the deterioration of quality of life (QOL) beyond 6 months after osteoporotic vertebral fractures (OVF). The purpose of this study was to identify the predictors associated with poor QOL improvement after OVF. METHODS: This post hoc analysis included 166 women aged 65-85 years with acute 1-level OVFs. For the patient-reported outcome measures, scores on the European Quality of Life-5 Dimensions (EQ-5D) scale, and visual analogue scale (VAS) for low back pain were used. Lateral radiography at 0, 12, and 48 weeks and magnetic resonance imaging (MRI) at enrollment and at 48 weeks were performed. The associations between baseline variables with change scores for EQ-5D were investigated using a multiple linear regression model. RESULTS: Univariate analysis showed that time since fracture, EQ-5D score, and VAS for low back pain at 0 week showed significant association with increased EQ-5D score from 0 to 48 weeks. According to the multiple regression analysis, the following equation was obtained: increased EQ-5D score from 0 to 48 weeks = 1.305 - 0.978 × EQ-5D at 0 week - 0.021 × VAS for low back pain at 0 week - 0.006 × age + (fluid-intensity T2-weighted MR image patterns: - 0.037, except for fluid-intensity T2-weighted MR image patterns: + 0.037). CONCLUSION: In conclusion, older patients with severe low back pain and fluid-intensity T2-weighted MR image patterns were more likely to have lower QOL improvements after OVFs and may therefore need extra support to improve QOL.

Risk factors for subsequent vertebral fracture after acute osteoporotic vertebral fractures.

PURPOSE: To investigate the incidence and characteristics of subsequent vertebral fracture after osteoporotic vertebral fractures (OVFs) and identify risk factors for subsequent vertebral fractures. METHODS: This post-hoc analysis from a prospective randomized multicenter trial included 225 patients with a 48-week follow-up period. Differences between the subsequent and non-subsequent fracture groups were analyzed. RESULTS: Of the 225 patients, 15 (6.7%) had a subsequent fracture during the 48-week follow-up. The annual incidence of subsequent vertebral fracture after fresh OVFs in women aged 65-85 years was 68.8 per 1000 person-years. Most patients (73.3%) experienced subsequent vertebral fractures within 6 months. At 48 weeks, European Quality of Life-5 Dimensions, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire pain-related disorder, walking ability, social life function, and lumbar function scores were significantly lower, while the visual analog scale (VAS) for low back pain was higher in patients with subsequent fracture. Cox proportional hazards analysis showed that a VAS score ≥ 70 at 0 weeks was an independent predictor of subsequent vertebral fracture. After adjustment for history of previous fracture, there was a ~ 67% reduction in the risk of subsequent vertebral fracture at the rigid-brace treatment. CONCLUSION: Women with a fresh OVF were at higher risk for subsequent vertebral fracture within the next year. Severe low back pain and use of soft braces were associated with higher risk of subsequent vertebral fractures. Therefore, when treating patients after OVFs with these risk factors, more attention may be needed for the occurrence of subsequent vertebral fractures. LEVEL OF EVIDENCE: III.

Preoperative scoring system for predicting early adjacent vertebral fractures after Balloon Kyphoplasty.

BACKGROUND: Adjacent vertebral fracture (AVF) is a major complication following Balloon Kyphoplasty (BKP). There is no scoring system for predicting AVF using only preoperative elements. The purposes of this study were to develop a scoring system for predicting early AVF after BKP based on preoperative factors and to investigate the appropriate surgical indication for BKP. METHODS: Of 220 patients who underwent BKP at a single institution since 2011, 65 patients over the age of 60 who had undergone a standing whole spine X-ray preoperatively were enrolled. Factors affecting the occurrence of early AVF were examined. A scoring system was created consisting of the factors exhibiting significant differences, and the correlation between the total score and the incidence of early AVF was investigated. RESULTS: Twenty of the 65 patients (30.8%) had early AVF. In a univariate analysis, age, previous vertebral fracture, pelvic tilt, and Local kyphosis significantly influenced early AVF. In a multivariate logistic regression analysis, age had an odds ratio of 1.136 (95% CI 1.001-1.289), previous vertebral fractures 4.181 (1.01-17.309), and Local kyphosis 1.103 (1.021-1.191). The scoring system was set as follows: ①Age (<75 years: 0 points(P), 75years≦: 1P), ②The number of previous vertebral fractures (0: 0 P, 1: 1P, 2: 2P, 3 or more: 3P), and ③Local kyphosis (<10°: 0P, 10°â‰¦: 1P). There was a correlation between the total score and the incidence of early AVF (r = 0.812, ∗P = 0.05). The incidence of early AVF was 6.4% (2 cases/31 cases) for a score of ≦1P and 54.5% (18 cases/33 cases) for a score of ≧2P. CONCLUSIONS: There was a correlation between the total score and the incidence of early AVF. A score of 1 point or less may represent the appropriate surgical indication for BKP.

Predictors of residual low back pain after acute osteoporotic compression fracture.

BACKGROUND: Studies on the clinical and radiographic risk factors for the residual low back pain beyond 6 months after osteoporotic vertebral fractures (OVFs) are lacking. Hence, this study aimed to characterize a patient population with residual low back pain 48 weeks after acute OVFs and to identify the risk factors associated with residual low back pain. METHODS: This prospective multicenter study included 166 female patients aged 65-85 years with acute one-level OVFs. We defined the residual low back pain as visual analog scale (VAS) for low back pain ≥3.5 at 48 weeks in this study, as VAS score ≥3.5 is used to describe moderate or severe pain. Thus, outcome and risk factor analyses were performed by comparing patients with VAS scores <3.5 and ≥ 3.5. In the radiographic analysis, the anterior vertebral body compression percentage was measured at 0, 12, and 48 weeks. Magnetic resonance imaging (MRI) was performed at enrollment and 48 weeks. RESULTS: Of the 166 patients analyzed, 58 complained of residual low back pain at 48 weeks after OVFs. At 0 weeks, the VAS score was significantly higher, and the JOABPEQ mental health score and anterior vertebral body compression percentage were significantly lower in patients with persistent pain 48 weeks after OVFs. The independent risk factors in the acute phase for persistent pain 48 weeks after OVFs were a high VAS score, MRI T2 fluid-intensity image pattern, and a lower anterior vertebral body compression percentage. CONCLUSIONS: Severe low back pain, MRI T2 fluid-intensity image pattern, and severe vertebral body collapse in the acute phase were significant risk factors for residual low back pain 48 weeks after OVFs. Patients with acute OVFs who have these risk factors should be carefully monitored for the possible development of residual chronic low back pain.

The evaluation of the distance between the popliteus tendon and the lateral collateral ligament footprint and the implant in Total knee Arthroplasty using a 3-dimensional template.

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.

How good are the outcomes of instrumented debulking operations for symptomatic spinal metastases and how long do they stand? A subgroup analysis in the global spine tumor study group database.

BACKGROUND: The benefits of surgery for symptomatic spinal metastases have been demonstrated, largely based on series of patients undergoing debulking and instrumentation operations. However, as cancer treatments improve and overall survival lengths increase, the incidence of recurrent spinal cord compression after debulking may increase. The aim of the current paper is to document the postoperative evolution of neurological function, pain, and quality of life following debulking and instrumentation in the Global Spine Tumor Study Group (GSTSG) database. METHODS: The GSTSG database is a prospective multicenter data repository of consecutive patients that underwent surgery for a symptomatic spinal metastasis. For the present analysis, patients were selected from the database that underwent decompressive debulking surgery with instrumentation. Preoperative tumor type, Tomita and Tokuhashi scores, EQ-5D, Frankel, Karnofsky, and postoperative complications, survival, EQ-5D, Frankel, Karnofsky, and pain numeric rating scores (NRS) at 3, 6, 12, and 24 months were analyzed. RESULTS: A total of 914 patients underwent decompressive debulking surgery with instrumentation and had documented follow-up until death or until 2 years post surgery. Median preoperative Karnofsky performance index was 70. A total of 656 patients (71.8%) had visceral metastases and 490 (53.6%) had extraspinal bone metastases. Tomita scores were evenly distributed above (49.1%) and below or equal to 5 (50.9%), and Tokuhashi scores almost evenly distributed below or equal to 8 (46.3%) and above 8 (53.7%). Overall, 12-month survival after surgery was 56.3%. The surgery resulted in EQ-5D health status improvement and NRS pain reduction that was maintained throughout follow-up. Frankel scores improved at first follow-up in 25.0% of patients, but by 12 months neurological deterioration was observed in 18.8%. CONCLUSION: We found that palliative debulking and instrumentation surgeries were performed throughout all Tomita and Tokuhashi categories. These surgeries reduced pain scores and improved quality of life up to 2 years after surgery. After initial improvement, a proportion of patients experienced neurological deterioration by 1 year, but the majority of patients remained stable.

Four Cases with Rare Complications of Intramedullary Screw Fixation for Jones Fracture.

Active treatment with intramedullary screw fixation is now common for athletes with Jones fracture. Outcomes are generally good, but complications can occur. We report 4 rare complications of intramedullary screw fixa-tion. Two cases developed osteomyelitis and pseudarthrosis caused by thermal necrosis. In the other two cases, screw-related complications occurred during the insertion of the tapered headless screw. Although thermal necrosis and screw insertion failures are considered rare complications and not widely reported in the litera-ture, they do occur occasionally. Knowing the mechanisms underlying these complications could help prevent them, and knowing their course could lead caregivers to appropriate interventions when they do occur.

Anatomical Evaluation of the Sacral Hiatus Using Ultrasound Imaging: Factors That Inhibit Needle Insertion During Caudal Epidural Block Procedures.

OBJECTIVE: Caudal epidural blocks often fail due to the difficulty of appropriate needle insertion. This study aimed to evaluate the anatomy of the sacral hiatus using ultrasound imaging. METHODS: This was a retrospective study involving 76 patients with spinal disorders. The following factors were analyzed to see if they affected the palpability of the sacral hiatus: sex, body mass index (BMI), and the morphology of the sacral hiatus on ultrasound imaging. The difficulty of needle insertion and the factors that influenced it were investigated in 28 of the 76 patients, who underwent landmark-based caudal epidural block procedures performed by the same doctor. RESULTS: Among the 76 patients, the mean length of the sacral hiatus was 21.3 ± 5.6 mm, the mean distance from the skin to the sacral cornua was 5.2 ± 3.4 mm, and the mean angle of the sacral hiatus was 16.4 ± 5.5 degrees. Sacral base protrusion was present and absent in 35 and 41 cases, respectively. The sacral hiatus exhibited good and poor palpability in 53 and 23 cases, respectively. The mean distance from the skin to the sacral cornua and BMI were found to significantly influence the palpability of the sacral hiatus. Only sacral base protrusion significantly influenced the difficulty of needle insertion. CONCLUSION: The mean distance from the skin to the sacral cornua and BMI were found to be associated with the palpability of the sacral hiatus, and sacral base protrusion was demonstrated to be associated with the difficulty of needle insertion into the sacral hiatus.

Delayed-onset paralysis induced by spontaneous spinal epidural hematoma communicated with hematoma in the paraspinal muscle in a 6-month-old girl: a case report.

Spontaneous spinal epidural hematoma (SSEH) very rarely develops in infants younger than 1 year old. To our knowledge, no previous case of delayed-onset paralysis induced by SSEH communicated with hematoma in the paraspinal muscle has been reported in the literature. The authors present the case of a 6-month-old girl with a tumor mass on her back who developed a paresis of her bilateral lower limbs. On spinal magnetic resonance imaging, the epidural mass appeared to be a dumbbell type and communicated with the mass in the paraspinal muscle through T12/L1 intervertebral foramen at the right side. After excision of the mass in the paraspinal muscle, hemi-laminectomy of T10-L3 was performed. No solid lesion was also present in the spinal canal and it was found to be an epidural hematoma. No malignancy was observed on pathological examination, and vascular and nerve system tumors were negative. When a tumor mass suddenly develops on the back of an infant and motor impairment of the lower limbs develops as the mass gradually enlarges, differential diagnosis should be performed taking SSEH into consideration.

Vertebral fracture in elderly female patients after posterior fusion with pedicle screw fixation for degenerative lumbar pathology: a retrospective cohort study.

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.

Reconstruction of Complete Peroneus Longus and Brevis Tendon Ruptures Using a Semitendinosus and Gracilis Tendon Graft.

The patient was a 40-year-old female who had been treated at our hospital for left peroneal tendonitis due to an ankle sprain 2 years earlier. She re-injured that ankle while dancing. The pain in the lateral left foot soon improved, but she had difficulty standing with the left foot in equinus. Complete peroneus longus and brevis tendon ruptures were diagnosed. The ipsilateral semitendinosus and gracilis tendons were harvested and used to reconstruct the tendons. Three months after surgery, the patient was able to stand in equinus, and at 5 months after surgery she resumed her original level of sports activities.

The correlation between the femoral anterior cruciate ligament footprint area and the morphology of the distal femur: three-dimensional CT evaluation in cadaveric knees.

BACKGROUNDS: "Anatomical" anterior cruciate ligament (ACL) reconstruction is defined as the functional restoration of the ACL to its native dimensions. It is essential to obtain more accurate predictors of ACL size before surgery. The purpose of this study was to investigate the correlation between the native femoral ACL footprint size and the morphology of the distal femur using three-dimensional CT (3D-CT). METHODS: Thirty non-paired Japanese human cadaver knees were used. All soft tissues around the knee were resected except the ACL. For the evaluation of femoral condyle morphology, trans-epicondylar length (TEL), notch outlet length, axial notch area, and notch width index were measured using 3D-CT. The ACL was cut in the middle, and the femoral bone was cut at the most proximal point of the femoral notch. The ACL was carefully dissected, and the boundaries of the ACL insertion site were outlined on the femoral side. An accurate lateral view of the femoral condyle was photographed with a digital camera. The size of the femoral ACL footprint, length of Blumensaat's line, and the height and area of the lateral wall of the femoral intercondylar notch were measured with ImageJ software. RESULTS: Notch height, lateral notch area, and TEL were significantly correlated with the femoral ACL footprint area. Both axial notch area and notch outlet length were significantly correlated with the femoral mid-substance insertion area. CONCLUSION: Morphological evaluation using 3D-CT preoperatively may be useful in predicting the femoral ACL footprint size.

Multiple vertebral fractures associated with glucocorticoid-induced osteoporosis treated with teriparatide followed by kyphosis correction fusion: a case report.

Surgical treatment of multiple vertebral fractures in patients with glucocorticoid-induced osteoporosis is difficult because of a high rate of secondary fracture postoperatively. A case is described in which initial treatment with teriparatide to improve osteoporosis followed by treatment of kyphosis with correction fusion achieved a favorable outcome. INTRODUCTION: Secondary fracture frequently occurs after treatment of vertebral fracture with vertebroplasty and balloon kyphoplasty in patients with glucocorticoid-induced osteoporosis, but effective treatment of multiple vertebral fractures has rarely been reported. Thus, a treatment of kyphosis following multiple vertebral fractures associated with glucocorticoid-induced osteoporosis is required. METHODS: The patient was a 24-year-old woman diagnosed with glucocorticoid-induced osteoporosis who was under treatment with oral alendronate, vitamin D, and elcatonin injection. Secondary multiple vertebral fractures occurred despite these treatments and low back pain gradually aggravated. RESULTS: Vertebroplasty or balloon kyphoplasty was not performed in the early phase. Instead, treatment with teriparatide was used for initial improvement of osteoporosis. Kyphosis in the center of the residual thoracolumbar junction was then treated with posterior correction fusion. At 2 years after surgery, the corrected position has been maintained and no new fracture has occurred. CONCLUSION: There is no established method for treatment of multiple vertebral fractures caused by glucocorticoid-induced osteoporosis. Initial treatment with teriparatide to improve osteoporosis followed by treatment of kyphosis with correction fusion may result in a more favorable outcome.

Treatment outcomes of patients with spinal metastases derived from hepatocellular carcinoma.

BACKGROUND: The prognosis of hepatocellular carcinoma (HCC) used to be poor, but it has recently improved, which has meant that clinicians have greater opportunity to treat spinal metastases and the associated epidural spinal cord compression. However, there have been few systematic functional studies about HCC-derived spinal metastases. The treatment outcomes of surgical treatment for HCC-derived metastatic spinal tumors were investigated. METHODS: The post-treatment survival period and pain, paralysis, and disturbance of activities of daily living (ADL) were investigated in 60 patients (surgery 25, conservative treatment 35). RESULTS: The mean post-treatment survival period was 7.4 ± 8.2 months (range 0.3-36 months). Univariate analysis indicated that the following factors influenced survival: the patient's general condition, presence/absence of major internal organ metastasis, serum albumin level, Child-Pugh classification, surgical treatment for spinal metastasis, and bone-modifying agent treatment. In the multivariate analysis of these 6 items, 3 significant factors were extracted: the patient's general condition, the serum albumin level, and bone-modifying agent treatment. Pain significantly improved in both groups (p < 0.001). Paralysis did not change significantly in the surgical group (p = 0.575), but it was significantly aggravated in the conservative treatment group (p = 0.047). The ADL abilities of the surgical group improved significantly (p < 0.001). CONCLUSION: Most patients exhibited poor survival. In the conservative treatment group, paralysis was significantly aggravated, and little improvement was seen in the patients' ADL abilities. In the surgical group, the patients' ADL abilities improved significantly, but their paralysis did not. Therefore, surgery should be actively performed for HCC-derived spinal metastasis whenever it is indicated.

Prognostic factors in patients with metastatic spine tumors derived from lung cancer-a novel scoring system for predicting life expectancy.

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.

The importance of Blumensaat's line morphology for accurate femoral ACL footprint evaluation using the quadrant method.

PURPOSE: The purpose of this study was to evaluate the difference in the center position of the ACL footprint based on grid placement using the quadrant method according to the morphological variations of the Blumensaat's line. METHODS: Fifty-nine non-paired human cadaver knees were used. The ACL was cut in the middle, and the femoral bone was cut at the most proximal point of the femoral notch, and the digital images were evaluated using Image J software. The femoral ACL footprint was periphery outlined and the center position was automatically measured. Following Iriuchishima's classification, the morphology of the Blumensaat's line was classified into straight, small hill, and large hill types. From the images, grid quadrants were placed as: Grid (1) without consideration of hill existence and not including the chondral lesion. Grid (2) without consideration of hill existence and including the chondral lesion. Grid (3) with consideration of hill existence and not including the chondral lesion. Grid (4) with consideration of hill existence and including the chondral lesion. RESULTS: The straight type consisted of 19 knees, the small hill type 13 knees, and the large hill type 27 knees. Depending on the quadrant grid placement, significant center position difference was observed both in the shallow-deep, and high-low direction. When hill existence was considered, the center position of the ACL was significantly changed to a high position. CONCLUSION: The center position of the ACL footprint exhibited significant differences according to Blumensaat's line morphology. For clinical relevance, when ACL surgery is performed in knees with small or large hill type variations, surgeons should pay close attention to femoral tunnel evaluation and placement, especially when using the quadrant method.

Transplantation of dedifferentiated fat cell-derived micromass pellets contributed to cartilage repair in the rat osteochondral defect model.

BACKGROUND: Mature adipocyte-derived dedifferentiated fat (DFAT) cells possesses the ability to proliferate effectively and the potential to differentiate into multiple linages of mesenchymal tissue; similar to adipose-derived stem cells (ASCs). The purpose of this study is to examine the effects of DFAT cell transplantation on cartilage repair in a rat model of osteochondral defects. METHODS: Full-thickness osteochondral defects were created in the knees of Sprague-Dawley rats bilaterally. Cartilage-like micromass pellets were prepared from green fluorescent protein (GFP)-labeled rat DFAT cells and subsequently transplanted into the affected right knee of these rats. Defects in the left knee were used as a control. Macroscopic and microscopic changes of treated and control defects were evaluated up to 12 weeks post-treatment with DFAT cells. To observe the transplanted cells, sectioned femurs were immunostained for GFP and type II collagen. RESULTS: DFAT cells formed micromass pellets expressing characteristics of immature cartilage in vitro. In the DFAT cell-transplanted limbs, the defects were completely filled with white micromass pellets as early as 2 weeks post-treatment. These limbs became smooth at 4 weeks. Conversely, the defects in the control limbs were still not repaired by 4 weeks. Macroscopic ICRS scores at 2 and 4 weeks were significantly higher in the DFAT cells-transplanted limbs compared to those of the control limbs. The modified O'Driscol histological scores for the DFAT cell-transplanted limbs were significantly higher than those of the control limbs at corresponding time points. GFP-positive DAFT cells were detected in the transplanted area at 2 weeks but hardly visible at 12 weeks post-operation. CONCLUSIONS: Transplantation of DFAT cell-derived micromass pellets contribute to cartilage repair in a rat osteochondral defect model. DFAT cell transplantation may be a viable therapeutic strategy for the repair of osteochondral injuries.

Compensatory mechanism of the spine after corrective surgery without lumbar-sacral fixation for traumatic thoracolumbar kyphotic spine deformity.

BACKGROUND: It remains unclear whether long fusion including lumbar-sacral fixation is needed in corrective surgery to obtain good global sagittal balance (GSB) for the treatment of traumatic thoracolumbar kyphotic spine deformity. The purposes of this study were to evaluate compensatory mechanism of the spine after corrective surgery without lumbar-sacral fixation and to evaluate the parameters affecting the achievement of good GSB post-operatively. METHODS: Twenty (20) subjects requiring corrective surgery (distal end of fixation was L3) were included in this study. The radiographic parameters were measured pre-operatively and at one month after surgery. Sagittal Vertical Axis (SVA), Lumber Lordosis angle altered by fracture (fLL), Thoracic Kyphosis angle altered by fracture (fTK), Pelvic Tilt (PT), Sacral Slope (SS), Pelvic Incidence (PI), Segmental Lumbar Lordosis (sLL: L3-S/L4-S), and local kyphotic angle were measured. The correlation between correction of local kyphotic angle (CLA) and the change in radiographic parameters was evaluated. Post-operatively, subjects with SVA<50 mm and PI-fLL<10°were regarded as the "good GSB group (G group). The radiographic parameters affecting the achievement of G group were statistically evaluated. RESULTS: fLL, sLL:L3-S and sLL:L4-S were decreased indirectly because the local kyphosis was corrected directly (CLA: 26.5 ± 8.6°) (P < 0.001). CLA and the change in fLL showed significant correlation (r = 0.821), the regression equation being: Y = -0.63X+3.31 (Y: The change in fLL, X: CLA). The radiographic parameters significantly affecting the achievement of G group were: SVA, PT, PI-fLL, sLL: L3-S, and sLL: L4-S (P < 0.01). CONCLUSION: The main compensatory mechanism was the decrease of lordosis in the lumbar spine. fLL was decreased to approximately 60% of CLA after surgery. SVA was not corrected by the compensatory mechanism.

Transplantation of dedifferentiation fat cells promotes intervertebral disc regeneration in a rat intervertebral disc degeneration model.

Our group has reported that mature adipocyte-derived dedifferentiated fat (DFAT) cells show multilineage differentiation potential similar to that observed in mesenchymal stem cells. In the present study, we examined whether DFAT cell transplantation could contribute to intervertebral disc regeneration using a rat intervertebral disc degeneration (IDD) model. The IDD was created in Sprague-Dawley rats by puncturing at level of caudal intervertebral disc under fluoroscopy. One week after injury, rat DFAT cells (5 × 104, DFAT group, n = 13) or phosphate-buffered saline (PBS, control group, n = 13) were injected into the intervertebral disc. Percent disc height index (%DHI) was measured every week and histology of injured disc was evaluated at 8 weeks after transplantation. Radiographic analysis revealed that the %DHI in the DFAT group significantly higher than that in the control group at 2-3 weeks after transplantation. Histological analysis revealed that ectopic formation of nucleus pulposus (NP)-like tissue at the outer layer of annulus fibrosus was frequently observed in the DFAT group but not in the control group. Transplantation experiments using green fluorescent protein (GFP)-labeled DFAT cells revealed that the ectopic NP-like tissue was positive for GFP, suggesting direct differentiation of DFAT cells into NP-like cells. In conclusion, DFAT cell transplantation promoted the regeneration of intervertebral disc and improved intervertebral disc height in the rat IDD model. Because adipose tissue is abundant and easily accessible, DFAT cell transplantation may be an attractive therapeutic strategy against IDD.