Intervertebral disc degeneration (IVDD) is a pathological condition that can lead to intractable ... more Intervertebral disc degeneration (IVDD) is a pathological condition that can lead to intractable back pain or secondary neurological deficits. There is no fundamental cure for this condition, and current treatments focus on alleviating symptoms indirectly. Numerous studies have been performed to date, and the major strategy for all treatments of IVDD is to prevent cell loss due to programmed or regulated cell death. Accumulating evidence suggests that several types of cell death other than apoptosis, including necroptosis, pyroptosis, and ferroptosis, are also involved in IVDD. In this study, we discuss the molecular pathway of each type of cell death and review the literature that has identified their role in IVDD. We also summarize the recent advances in targeted therapy at the RNA level, including RNA modulations through RNA interference and regulation of non-coding RNAs, for preventing cell death and subsequent IVDD. Therefore, we review the causes and possible therapeutic targe...
2 The authors report cases of 3 patients with tuberculous spondylodiscitis. All patients suffered... more 2 The authors report cases of 3 patients with tuberculous spondylodiscitis. All patients suffered from severe back or low back pain. Posterolateral endoscopic debridement and irrigation was performed followed by retention of a drainage tube at the affected sites. Additional puncture and drainage was conducted at the same time when extensive cold abscesses were identified around the paravertebral muscle. All patients experienced immediate pain relief postoperatively. This technique is effective for rapid pain relief and in obtaining neurological resolution for patients in the early stages of tuberculous spondylodiscitis and may also be a good method of preventing further vertebral collapse and kyphotic spinal deformity such as Gibbus vertebrae.
S u m m a r y o f B a c k g r o u n d D a t a . Only one previous case has been reported of a hem... more S u m m a r y o f B a c k g r o u n d D a t a . Only one previous case has been reported of a hematoma derived from the ligamentum flavum in the thoracic spine. Methods. A 61year-old male presented with gait disturbance and numbness below the navel. Magnetic resonance imaging (MRI) on the 16th day after the onset of the symptoms showed spinal cord compression at the T10-11 level caused by a round mass. This intraspinal, extradural space occupying lesion, continuous with ligamentum flavum was centrally hypointense and marginal hyperintense on a T1-weighted image and central heterogeneous and marginal hypointense on a T2-weighted image. The wall of the lesion was slightly enhanced after use of a contrast medium. Results. The patient underwent a T10 laminectomy and the mass was carefully resected from the dura mater. Histologic examination showed that the wall of the mass comprised fibrous connective tissue that contained elastic fibers derived from a degenerative ligamentum flavum Hem...
Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation... more Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation surgical schemes for adolescent idiopathic scoliosis (AIS) should consider anatomical corrections. A four-dimensional correction could be actively achieved by curving the rod. Thus, anatomically designed rods have been developed as notch-free, pre-bent rods for easier anatomical reconstruction. This study aimed to compare the initial curve corrections obtained using notch-free rods and manually bent, notched rods for the anatomical reconstruction of thoracic AIS. Two consecutive series of 60 patients who underwent anatomical posterior correction for main thoracic AIS curves were prospectively followed up. After multilevel facetectomy, except for the lowest instrumented segment, either notch-free or notched rods were used. Patient demographic data, radiographic measurements, and sagittal rod angles were analyzed within 1Â week after surgery. Patients with notch-free rods had significantly...
Aims The aims of our study were to provide long-term information on the behaviour of the thoracol... more Aims The aims of our study were to provide long-term information on the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic anterior correction and fusion (ASF) and to determine the impact of ASF on pulmonary function. Patients and Methods A total of 41 patients (four males, 37 females) with main thoracic (MT) adolescent idiopathic scoliosis (AIS) treated with ASF were included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up period was 13.5 years (10 to 18). Results For the TL/L curve, the mean curve flexibility evaluated with supine pre-operative bending radiographs was 78.6% (standard deviation 16.5%), with no significant loss of correction observed. On comparing patients with an increase of the TL/L curve increase (> 4º, n = 9, 22%) to those without, significant differences were observed in the correction rate of the MT curve at the final follow-up (p = 0.011), correction loss of the MT curve (p = 0.003) and the proportion of patients who had semi-...
Approximately 40% of people under 30 and over 90% of people 55 or older suffer from moderate-to-s... more Approximately 40% of people under 30 and over 90% of people 55 or older suffer from moderate-to-severe levels of degenerative intervertebral disc (IVD) disease in their lumbar spines. Surgical treatments are sometimes effective; however, the treatment of back pain related to IVD degeneration is still a challenge; therefore, new treatments are necessary. Apoptosis may be important in IVD degeneration because suppressing cell apoptosis inside the IVD inhibits degeneration. Caspase-3, the primary effector of apoptosis, may be a key treatment target. We analyzed caspase-3’s role in two different types of IVD degeneration using caspase-3 knockout (Casp-3 KO) mice. Casp-3 KO delayed IVD degeneration in the injury-induced model but accelerated it in the age-induced model. Our results suggest that this is due to different pathological mechanisms of these two types of IVD degeneration. Apoptosis was suppressed in the IVD cells of Casp-3 KO mice, but cellular senescence was enhanced. This wou...
Postoperative infection is a potentially devastating complication of spine surgery and an appropr... more Postoperative infection is a potentially devastating complication of spine surgery and an appropriate strategy and timely decision-making are essential for successful treatment of deep surgical site infection (SSI) after spinal instrumentation surgeries. However, there is a lack of consensus on implant removal or retention. We report on a case of deep SSI after posterior lumbar interbody fusion (PLIF) surgery in which we achieved clinical cure by debridement and removal of the interbody fusion cage without removing the percutaneously inserted pedicle screws (PPS). A case was a 53-year-old woman with deep SSI after PLIF surgery using the PPS system at the L4-5 level. Computed tomography (CT) showed no clear radiolucent line around the screws and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT demonstrated abnormal FDG uptake around the cages and no uptake around the pedicle screws. Intervertebral cages were removed and iliac bone grafts were inserted between the vert...
OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented v... more OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented vertebra (UIV) translation from the C7 plumb line (C7PL) on the long-term postoperative results of patients with main thoracic (MT) adolescent idiopathic scoliosis (AIS).METHODSTwenty-five patients had been treated surgically for AIS with a Lenke type 1 curve and had been followed up for a mean period of 18.2 years. Radiographic parameters, pulmonary function measurements, and clinical outcomes were compared between the patients (n = 15) with UIV translation < 20 mm and those (n = 10) with UIV translation ≥ 20 mm at the final follow-up. Correlations between UIV translation and radiographic or pulmonary function parameters were analyzed.RESULTSPatients with ≥ 20 mm UIV translation at the final follow-up had a significantly larger preoperative UIV translation than that in the patients with < 20 mm UIV translation at follow-up. The former group also had a significantly lower correction...
Prospective, non-randomized study. To assess surgical outcomes of multilevel facetectomy and rod ... more Prospective, non-randomized study. To assess surgical outcomes of multilevel facetectomy and rod curvature with simultaneous double-rod rotation technique for anatomical spinal reconstruction in thoracic adolescent idiopathic scoliosis (AIS). Although some surgical techniques maintain or restore thoracic kyphosis (TK), next-generation strategies for thoracic AIS should include corrections in three anatomical planes. The study included 39 consecutive patients with Lenke 1 or Lenke 2 thoracic AIS treated at our institution. After all-level facetectomy at instrumentation level, except for the lowest intervertebral segment, two rods were identically bent to guide postoperative anatomical TK without reference to the intraoperative coronal alignment of the AIS deformity. Outcome measures included patient demographics, radiographic measurements, and Scoliosis Research Society (SRS) questionnaire scores. After two years of follow-up, the average main thoracic Cobb angle correction rate was ...
Aims A total of 30 patients with thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) treat... more Aims A total of 30 patients with thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) treated between 1989 and 2000 with anterior correction and fusion surgery using dual-rod instrumentation were reviewed. Patients and Methods Radiographic parameters and clinical outcomes were compared among patients with lowest instrumented vertebra (LIV) at the lower end vertebra (LEV; EV group) (n = 13) and those treated by short fusion (S group), with LIV one level proximal to EV (n = 17 patients). Results The allocation of the surgical technique was determined by the flexibility of the TL/L curves and/or neutral vertebrae located one level above LEV as determined on preoperative radiographs. If these requirements were met a short fusion was performed. The mean follow-up period was 21.4 years (16 to 27). The mean correction rate at final follow-up was significantly lower in the S group (74 sd 11%) than in the EV group (88 sd 13%) (p = 0.004).Coronal and sagittal balance, thoracic kyphosis,...
Flattening of the preimplantation rod contour in the sagittal plane influences thoracic kyphosis ... more Flattening of the preimplantation rod contour in the sagittal plane influences thoracic kyphosis (TK) restoration in adolescent idiopathic scoliosis (AIS) surgery. The effects of multilevel facetectomy and screw density on postoperative changes in spinal rod contour have not been documented. This study aimed to evaluate the effects of multilevel facetectomy and screw density on changes in spinal rod contour from before implantation to after surgical correction of thoracic curves in patients with AIS prospectively. The concave and convex rod shapes from patients with thoracic AIS (n = 49) were traced prior to insertion. Postoperative sagittal rod shape was determined by computed tomography. The angle of intersection of the tangents to the rod end points was measured. Multiple stepwise linear regression analysis was used to identify variables independently predictive of change in rod contour (Δθ). Average Δθ at the concave and convex side were 13.6° ± 7.5° and 4.3° ± 4.8°, respectivel...
Improvement of material property in spinal instrumentation has brought better deformity correctio... more Improvement of material property in spinal instrumentation has brought better deformity correction in scoliosis surgery in recent years. The increase of mechanical strength in instruments directly means the increase of force, which acts on bone-implant interface during scoliosis surgery. However, the actual correction force during the correction maneuver and safety margin of pull out force on each screw were not well known. In the present study, estimated corrective forces and pull out forces were analyzed using a novel method based on Finite Element Analysis (FEA). Twenty adolescent idiopathic scoliosis patients (1 boy and 19 girls) who underwent reconstructive scoliosis surgery between June 2009 and Jun 2011 were included in this study. Scoliosis correction was performed with 6mm diameter titanium rod (Ti6Al7Nb) using the simultaneous double rod rotation technique (SDRRT) in all cases. The pre-maneuver and post-maneuver rod geometry was collected from intraoperative tracing and po...
A retrospective clinical case series. To evaluate the association between C1-C2 fixation angle an... more A retrospective clinical case series. To evaluate the association between C1-C2 fixation angle and postoperative C2-C7 alignment in the sagittal plane after C1 lateral mass screw with C2 pedicle screw fixation (C1-LMS) or Magerl with wiring technique. Various techniques for posterior correction and fusion, such as the Magerl procedure with posterior wiring and C1-LMS procedures, are used for treating atlantoaxial instability. However, only few studies investigating the relationship between postoperative C1-C2 angle and C2-C7 sagittal alignment change after C1-C2 fixation have been reported. We retrospectively followed up 42 patients who underwent the C1-LMS (22 patients) or Magerl with wiring procedure (20 patients) to treat C1-C2 instability for >2 years. The atlantodental interval, space available for the spinal cord, and O-C1, C1-C2, C2-C3, and C2-C7 angles were measured. Significant reduction in atlantodental interval and increase in space available for the spinal cord were o...
Intervertebral disc degeneration (IVDD) is a pathological condition that can lead to intractable ... more Intervertebral disc degeneration (IVDD) is a pathological condition that can lead to intractable back pain or secondary neurological deficits. There is no fundamental cure for this condition, and current treatments focus on alleviating symptoms indirectly. Numerous studies have been performed to date, and the major strategy for all treatments of IVDD is to prevent cell loss due to programmed or regulated cell death. Accumulating evidence suggests that several types of cell death other than apoptosis, including necroptosis, pyroptosis, and ferroptosis, are also involved in IVDD. In this study, we discuss the molecular pathway of each type of cell death and review the literature that has identified their role in IVDD. We also summarize the recent advances in targeted therapy at the RNA level, including RNA modulations through RNA interference and regulation of non-coding RNAs, for preventing cell death and subsequent IVDD. Therefore, we review the causes and possible therapeutic targe...
2 The authors report cases of 3 patients with tuberculous spondylodiscitis. All patients suffered... more 2 The authors report cases of 3 patients with tuberculous spondylodiscitis. All patients suffered from severe back or low back pain. Posterolateral endoscopic debridement and irrigation was performed followed by retention of a drainage tube at the affected sites. Additional puncture and drainage was conducted at the same time when extensive cold abscesses were identified around the paravertebral muscle. All patients experienced immediate pain relief postoperatively. This technique is effective for rapid pain relief and in obtaining neurological resolution for patients in the early stages of tuberculous spondylodiscitis and may also be a good method of preventing further vertebral collapse and kyphotic spinal deformity such as Gibbus vertebrae.
S u m m a r y o f B a c k g r o u n d D a t a . Only one previous case has been reported of a hem... more S u m m a r y o f B a c k g r o u n d D a t a . Only one previous case has been reported of a hematoma derived from the ligamentum flavum in the thoracic spine. Methods. A 61year-old male presented with gait disturbance and numbness below the navel. Magnetic resonance imaging (MRI) on the 16th day after the onset of the symptoms showed spinal cord compression at the T10-11 level caused by a round mass. This intraspinal, extradural space occupying lesion, continuous with ligamentum flavum was centrally hypointense and marginal hyperintense on a T1-weighted image and central heterogeneous and marginal hypointense on a T2-weighted image. The wall of the lesion was slightly enhanced after use of a contrast medium. Results. The patient underwent a T10 laminectomy and the mass was carefully resected from the dura mater. Histologic examination showed that the wall of the mass comprised fibrous connective tissue that contained elastic fibers derived from a degenerative ligamentum flavum Hem...
Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation... more Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation surgical schemes for adolescent idiopathic scoliosis (AIS) should consider anatomical corrections. A four-dimensional correction could be actively achieved by curving the rod. Thus, anatomically designed rods have been developed as notch-free, pre-bent rods for easier anatomical reconstruction. This study aimed to compare the initial curve corrections obtained using notch-free rods and manually bent, notched rods for the anatomical reconstruction of thoracic AIS. Two consecutive series of 60 patients who underwent anatomical posterior correction for main thoracic AIS curves were prospectively followed up. After multilevel facetectomy, except for the lowest instrumented segment, either notch-free or notched rods were used. Patient demographic data, radiographic measurements, and sagittal rod angles were analyzed within 1Â week after surgery. Patients with notch-free rods had significantly...
Aims The aims of our study were to provide long-term information on the behaviour of the thoracol... more Aims The aims of our study were to provide long-term information on the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic anterior correction and fusion (ASF) and to determine the impact of ASF on pulmonary function. Patients and Methods A total of 41 patients (four males, 37 females) with main thoracic (MT) adolescent idiopathic scoliosis (AIS) treated with ASF were included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up period was 13.5 years (10 to 18). Results For the TL/L curve, the mean curve flexibility evaluated with supine pre-operative bending radiographs was 78.6% (standard deviation 16.5%), with no significant loss of correction observed. On comparing patients with an increase of the TL/L curve increase (> 4º, n = 9, 22%) to those without, significant differences were observed in the correction rate of the MT curve at the final follow-up (p = 0.011), correction loss of the MT curve (p = 0.003) and the proportion of patients who had semi-...
Approximately 40% of people under 30 and over 90% of people 55 or older suffer from moderate-to-s... more Approximately 40% of people under 30 and over 90% of people 55 or older suffer from moderate-to-severe levels of degenerative intervertebral disc (IVD) disease in their lumbar spines. Surgical treatments are sometimes effective; however, the treatment of back pain related to IVD degeneration is still a challenge; therefore, new treatments are necessary. Apoptosis may be important in IVD degeneration because suppressing cell apoptosis inside the IVD inhibits degeneration. Caspase-3, the primary effector of apoptosis, may be a key treatment target. We analyzed caspase-3’s role in two different types of IVD degeneration using caspase-3 knockout (Casp-3 KO) mice. Casp-3 KO delayed IVD degeneration in the injury-induced model but accelerated it in the age-induced model. Our results suggest that this is due to different pathological mechanisms of these two types of IVD degeneration. Apoptosis was suppressed in the IVD cells of Casp-3 KO mice, but cellular senescence was enhanced. This wou...
Postoperative infection is a potentially devastating complication of spine surgery and an appropr... more Postoperative infection is a potentially devastating complication of spine surgery and an appropriate strategy and timely decision-making are essential for successful treatment of deep surgical site infection (SSI) after spinal instrumentation surgeries. However, there is a lack of consensus on implant removal or retention. We report on a case of deep SSI after posterior lumbar interbody fusion (PLIF) surgery in which we achieved clinical cure by debridement and removal of the interbody fusion cage without removing the percutaneously inserted pedicle screws (PPS). A case was a 53-year-old woman with deep SSI after PLIF surgery using the PPS system at the L4-5 level. Computed tomography (CT) showed no clear radiolucent line around the screws and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT demonstrated abnormal FDG uptake around the cages and no uptake around the pedicle screws. Intervertebral cages were removed and iliac bone grafts were inserted between the vert...
OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented v... more OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented vertebra (UIV) translation from the C7 plumb line (C7PL) on the long-term postoperative results of patients with main thoracic (MT) adolescent idiopathic scoliosis (AIS).METHODSTwenty-five patients had been treated surgically for AIS with a Lenke type 1 curve and had been followed up for a mean period of 18.2 years. Radiographic parameters, pulmonary function measurements, and clinical outcomes were compared between the patients (n = 15) with UIV translation < 20 mm and those (n = 10) with UIV translation ≥ 20 mm at the final follow-up. Correlations between UIV translation and radiographic or pulmonary function parameters were analyzed.RESULTSPatients with ≥ 20 mm UIV translation at the final follow-up had a significantly larger preoperative UIV translation than that in the patients with < 20 mm UIV translation at follow-up. The former group also had a significantly lower correction...
Prospective, non-randomized study. To assess surgical outcomes of multilevel facetectomy and rod ... more Prospective, non-randomized study. To assess surgical outcomes of multilevel facetectomy and rod curvature with simultaneous double-rod rotation technique for anatomical spinal reconstruction in thoracic adolescent idiopathic scoliosis (AIS). Although some surgical techniques maintain or restore thoracic kyphosis (TK), next-generation strategies for thoracic AIS should include corrections in three anatomical planes. The study included 39 consecutive patients with Lenke 1 or Lenke 2 thoracic AIS treated at our institution. After all-level facetectomy at instrumentation level, except for the lowest intervertebral segment, two rods were identically bent to guide postoperative anatomical TK without reference to the intraoperative coronal alignment of the AIS deformity. Outcome measures included patient demographics, radiographic measurements, and Scoliosis Research Society (SRS) questionnaire scores. After two years of follow-up, the average main thoracic Cobb angle correction rate was ...
Aims A total of 30 patients with thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) treat... more Aims A total of 30 patients with thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) treated between 1989 and 2000 with anterior correction and fusion surgery using dual-rod instrumentation were reviewed. Patients and Methods Radiographic parameters and clinical outcomes were compared among patients with lowest instrumented vertebra (LIV) at the lower end vertebra (LEV; EV group) (n = 13) and those treated by short fusion (S group), with LIV one level proximal to EV (n = 17 patients). Results The allocation of the surgical technique was determined by the flexibility of the TL/L curves and/or neutral vertebrae located one level above LEV as determined on preoperative radiographs. If these requirements were met a short fusion was performed. The mean follow-up period was 21.4 years (16 to 27). The mean correction rate at final follow-up was significantly lower in the S group (74 sd 11%) than in the EV group (88 sd 13%) (p = 0.004).Coronal and sagittal balance, thoracic kyphosis,...
Flattening of the preimplantation rod contour in the sagittal plane influences thoracic kyphosis ... more Flattening of the preimplantation rod contour in the sagittal plane influences thoracic kyphosis (TK) restoration in adolescent idiopathic scoliosis (AIS) surgery. The effects of multilevel facetectomy and screw density on postoperative changes in spinal rod contour have not been documented. This study aimed to evaluate the effects of multilevel facetectomy and screw density on changes in spinal rod contour from before implantation to after surgical correction of thoracic curves in patients with AIS prospectively. The concave and convex rod shapes from patients with thoracic AIS (n = 49) were traced prior to insertion. Postoperative sagittal rod shape was determined by computed tomography. The angle of intersection of the tangents to the rod end points was measured. Multiple stepwise linear regression analysis was used to identify variables independently predictive of change in rod contour (Δθ). Average Δθ at the concave and convex side were 13.6° ± 7.5° and 4.3° ± 4.8°, respectivel...
Improvement of material property in spinal instrumentation has brought better deformity correctio... more Improvement of material property in spinal instrumentation has brought better deformity correction in scoliosis surgery in recent years. The increase of mechanical strength in instruments directly means the increase of force, which acts on bone-implant interface during scoliosis surgery. However, the actual correction force during the correction maneuver and safety margin of pull out force on each screw were not well known. In the present study, estimated corrective forces and pull out forces were analyzed using a novel method based on Finite Element Analysis (FEA). Twenty adolescent idiopathic scoliosis patients (1 boy and 19 girls) who underwent reconstructive scoliosis surgery between June 2009 and Jun 2011 were included in this study. Scoliosis correction was performed with 6mm diameter titanium rod (Ti6Al7Nb) using the simultaneous double rod rotation technique (SDRRT) in all cases. The pre-maneuver and post-maneuver rod geometry was collected from intraoperative tracing and po...
A retrospective clinical case series. To evaluate the association between C1-C2 fixation angle an... more A retrospective clinical case series. To evaluate the association between C1-C2 fixation angle and postoperative C2-C7 alignment in the sagittal plane after C1 lateral mass screw with C2 pedicle screw fixation (C1-LMS) or Magerl with wiring technique. Various techniques for posterior correction and fusion, such as the Magerl procedure with posterior wiring and C1-LMS procedures, are used for treating atlantoaxial instability. However, only few studies investigating the relationship between postoperative C1-C2 angle and C2-C7 sagittal alignment change after C1-C2 fixation have been reported. We retrospectively followed up 42 patients who underwent the C1-LMS (22 patients) or Magerl with wiring procedure (20 patients) to treat C1-C2 instability for >2 years. The atlantodental interval, space available for the spinal cord, and O-C1, C1-C2, C2-C3, and C2-C7 angles were measured. Significant reduction in atlantodental interval and increase in space available for the spinal cord were o...
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