Jeong-Yoon Park

Triamcinolone decreases bupivacaine toxicity to intervertebral disc cell in vitro

BACKGROUND CONTEXTnLocal anesthetics combined with corticosteroids are commonly used for management of back pain in interventional spinal procedures. Several recent studies suggest cytotoxicity of bupivacaine, whereas others report protective and cytotoxic effects of corticosteroids on chondrocytes and intervertebral disc cells. Considering the frequent use of these agents in spinal interventions, it is meaningful to know how they affect intervertebral disc cells.nnnPURPOSEnThis study was conducted to assess the effects of bupivacaine and triamcinolone, both alone and in combination, on viability of intervertebral disc cells inxa0vitro.nnnSTUDY DESIGNnControlled laboratory study.nnnMETHODSnNucleus pulposus cells were isolated from human disc specimens from patients undergoing surgery because of disc herniation or degenerative disc disease. They were grown in three-dimensional alginate beads for 1 week to maintain their differentiated phenotypes and to allow for matrix formation before analysis. After 1 week of culture, the cells were exposed to bupivacaine (0.1%, 0.25%, 0.5%, and 1%) or bupivacaine (0.1%, 0.25%, 0.5%, and 1%) with 1 mg of triamcinolone for 1, 3, or 6 hours. Cell viability was measured using trypan blue exclusion assay and flow cytometry. Live cell/dead cell fluorescent imaging was assessed using confocal microscopy.nnnRESULTSnTrypan blue exclusion assays demonstrated dose- and time-dependent cytotoxic effects of bupivacaine on human nucleus pulposus cells. Similar but reduced cytotoxicity was observed after exposure to the combination of bupivacaine and 1 mg of triamcinolone. Flow cytometry showed a dose-dependent cytotoxic effect of bupivacaine on nucleus pulposus cells after 3 hours of exposure. The reduced cytotoxicity of bupivacaine combined with 1 mg of triamcinolone was also confirmed in flow cytometry. Confocal images showed that the increase in dead cells correlated with the concentration of bupivacaine. Nevertheless, fewer cells died after exposure to several different concentrations of bupivacaine combined with 1 mg of triamcinolone than did after exposure to bupivacaine alone.nnnCONCLUSIONSnThe combination of bupivacaine and triamcinolone induced dose- and time-dependent cytotoxicity on human intervertebral disc cells inxa0vitro, but the cytotoxicity was much weaker than that of bupivacaine alone. This study shows a potential protective influence of triamcinolone on intervertebral disc cells.

Anatomical parameters of fifth lumbar vertebra in L5–S1 spondylolytic spondylolisthesis from a surgical point of view

PurposeWe measured the length, width, height, and angles related to both Meyerding grading system and Marchetti–Bartolozzi classification in L5–S1 spondylolytic spondylolisthesis patients to investigate the anatomical characteristics of fifth lumbar pedicles.MethodsSeventy patients with L5–S1 spondylolytic spondylolisthesis and general spinal disease were included. Patient attributes, Meyerding grading system and Marchetti–Bartolozzi classification of spondylolisthesis, length, width, height of L4 and L5 pedicle, and the angle between pedicle and vertebral midline were measured. The heights of L5 vertebral body, divided as anterior, mid, and posterior were also measured.ResultsThe pedicle is elongated and the angle of the pedicle is wider in cases of L5–S1 spondylolysis. Vertebral body shape was more posteriorly wedged in L5–S1 spondylolysis. Pedicles were more narrow and shorter in L5–S1 spondylolysis.ConclusionsIn L5–S1 spondylolytic spondylolisthesis, a longer screw is suitable for insertion of L5 pedicle and the screw should be inserted more medially compared to patients without spondylolysis.

Which iodinated contrast media is the least cytotoxic to human disc cells

BACKGROUNDnIodinated contrast media (CM) is commonly used for various intradiscal injections such as in discography and endoscopic spinal surgery. However, CM has been shown to be toxic to renal tissue due to its ionic strength and osmolarity and as a result of iodine-induced cytotoxicity, which has raised concern over whether there are similar negative effects on disc cells.nnnPURPOSEnThis inxa0vitro study was designed to identify the least cytotoxic iodinated CM to the human disc cell among four different physiochemical iodinated contrast dyes.nnnSTUDY DESIGNnInxa0vitro laboratory study.nnnMETHODSnIntervertebral disc tissue was obtained by discectomy from a total of 10 lumbar disc patients undergoing surgery and disc cells were isolated. The human disc cells were grown in 3D alginate bead culture with 0, 0.1, 10, and 100 mg/mL CM solutions (ionic dimer, ionic monomer, non-ionic dimer, and non-ionic monomer) and mannitol as a control for 2 days. The living cells were analyzed with trypan blue staining. Fluorescence-activated cell sorting analysis was performed using Annexin V and propidium iodide (PI) and 3D alginate bead immunostaining to identify live, apoptotic, and necrotic cells.nnnRESULTSnHuman disc cell death was time- and dose-dependent in response to CM and more necrosis was observed than apoptosis. In addition, non-ionic dimeric CM (iodixanol) showed the least toxic effect on human disc cells, followed by non-ionic monomeric (iopromide), ionic dimeric (ioxaglate), and ionic monomeric CM (ioxithalamate).nnnCONCLUSIONSnContrast media is cytotoxic to human disc cells in a dose- and time-dependent manner. This inxa0vitro study revealed that, among four different CM preparations, non-ionic dimeric CM is the least detrimental to human disc cell viability. Careful attention should be paid to the type of CM chosen for discography and endoscopic spinal surgery. It is also necessary to investigate the detrimental effects of CM on disc cells and disc degeneration in further inxa0vivo studies.

Time- and dose-dependent cytotoxicities of ioxitalamate and indigocarmine in human nucleus pulposus cells.

BACKGROUND CONTEXTnIoxitalamate (Telebrix 300) is an ionic iodinated contrast medium commonly used for discography or percutaneous endoscopic lumbar discectomy (PELD), though itxa0has side effects such as anaphylactic shock and renal toxicity. Indigocarmine is an organic compound dye with a distinctive blue color that is commonly used during PELD to stain the acidic, degenerated nucleus pulposus (NP). Although ioxitalamate and indigocarmine are widely used inxa0spinal surgery, there have been no reports on their effects on NP cells. We studied the toxicities of both ioxitalamate and indigocarmine to NP cells.nnnPURPOSEnTo determine the toxicities of both ioxitalamate and indigocarmine to NP cells inxa0vitro.nnnSTUDY DESIGNnInxa0vitro, controlled study of the toxicities of both ioxitalamate and indigocarmine to human NP cells.nnnMETHODSnNucleus pulposus cells were obtained via discectomy from lumbar disc patients and isolated. Nucleus pulposus cells were cultured in three-dimensional (3D) alginate beads with 0.001, 0.1, 10, and 100 mg/mL ioxitalamate, 0.00001, 0.001, 0.1, and 10 mg/mL indigocarmine, or a mixture of both for 1, 2, or 3 days. The living cells were analyzed with trypan blue staining. Fluorescence Activated Cell Sorting analysis using Annexin V and propidium iodide and 3D alginate bead immunostaining was performed to identify live, apoptotic, and necrotic cells.nnnRESULTSnIoxitalamate, indigocarmine, and their combination induced statistically significant NP cell injury that was both time- and dose dependent (p<.05). Also, at the same concentration, ioxitalamate was more cytotoxic than was indigocarmine or the combination (p<.05). All three treatments also showed dose-dependent cytotoxicity according to flow cytometry and immunostaining.nnnCONCLUSIONSnIoxitalamate and indigocarmine are toxic to human NP cells inxa0vitro in a time- and dose-dependent manner. We assume that ioxitalamate and indigocarmine may have similar effects in patients undergoing discography and PELD. Thus, we suggest that ioxitalamate and indigocarmine should be used carefully at low concentrations.

Changes in Bone Metabolism in Young Castrated Male Rats.

Purpose To determine the window of time during which osteoporosis affects the management of spinal surgery and the mechanism of bone metabolism changes in males with osteoporosis by examining changes in bone metabolism in young castrated male rats. Materials and Methods A total of 30 Sprague-Dawley rats were randomly allocated into two study groups. Group 1 (control) received a sham surgery and Group 2 received bilateral orchiectomy to change bone mineral density (BMD). Serum osteocalcin, alkaline phosphatase (ALP), and collagen type 1 cross-linked C-telopeptide (CTX) were analyzed at postoperative date (POD) 8, 10, and 12 weeks. BMDs were measured using micro computed tomography scans. Results Femoral and lumbar BMDs were decreased in the orchiectomy groups. BMDs in the sham and orchiectomy groups showed statistically differences at POD 8, 10, and 12 weeks for the femur (p=0.032, 0.008, 0.008) and lumbar spine (p=0.151, 0.008, 0.008, respectively). Serum osteocalcin, ALP, and CTX decreased gradually; however, N-terminal type 1 procollagen (P1NP) showed a slight increase yet no significant change. Conclusion In young castrated male rats, a significant decrease in BMD was observed after orchiectomy due to the mixture of two detrimental factors. Young castrated male rats did not reach peak BMD. Increased bone turnover causes bone resorption to exceed bone formation. This study may contribute to the creation of a valuable model for studies of male osteoporosis and the spinal surgery field.

Clinical outcomes and considerations of the lumbar interbody fusion technique for lumbar disk disease in adolescents

PurposeThe posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) techniques are commonly used surgical methods for wide indications such as degeneration or trauma. Although they are rarely required for lumbar disk disease in younger patients, there are a few children and adolescents who are indicated for PLIF or TLIF for other reasons, such as congenital severe stenosis with or without lumbar instability that requires wide decompression or severe bony spur that need to be removed. In such cases, different pathophysiology and outcomes are expected compared with adult patients.MethodsWe retrospectively reviewed data of 23 patients who underwent PLIF or TLIF surgery when less than 20xa0years old. Clinical and radiographic outcomes were assessed during a mean of 36.4 months follow-up period. The indications of lumbar interbody fusion, success of fusion, complications, and visual analog scale (VAS) were analyzed.ResultsRadiographs of all patients taken 6xa0months after the surgery showed fusion. Clinical outcome was also satisfactory, with improvement of VAS score from 7.7 preoperatively to 2.3 at 6xa0months after surgery. Only one patient had reoperation due to adjacent segment disease.ConclusionsFor adolescent patients with severe bony spur, massive central disk rupture, or severe spondylolisthesis, lumbar interbody fusion surgery has good surgical outcome with few complications.

The Influences of Different Ratios of Biphasic Calcium Phosphate and Collagen Augmentation on Posterior Lumbar Spinal Fusion in Rat Model

Purpose To determine the influence of different ratios of hydroxyapatite (HA)/beta tricalcium phosphate (β-TCP) and collagen augmentation for posterior lumbar fusion in a rat model. Materials and Methods We generated a posterior lumbar fusion model in 50 rats and divided it into five groups of equal number as follows; 1) autologous bone graft as group A, 2) 70% HA+30% β-TCP as group B, 3) 70% HA+30% β-TCP+collagen as group C, 4) 30% HA+70% β-TCP as group D, and 5) 30% HA+70% β-TCP+collagen as group E. Rats were euthanized at 12 weeks after surgery and fusion was assessed by manual palpation, quantitative analysis using microCT and histology. Results The score of manual palpation was significantly higher in group C than group E (3.1±1.1 vs. 1.8±0.8, p=0.033). However, in terms of microCT analysis, group D showed significantly higher scores than group B (5.5±0.8 vs. 3.1±1.1, p=0.021). According to quantitative volumetric analysis, 30% HA+70% β-TCP groups (group D and E) showed significantly reduced fusion mass at 12 weeks after surgery (123±14.2, 117±46.3 vs. 151±27.3, p=0.008, 0.003, respectively). Collagen augmentation groups revealed superior results in terms of both microCT score and histologic grade. Conclusion A 7:3 HA/β-TCP ratio with collagen augmentation rather than a 3:7 HA/β-TCP ratio could be a more favorable graft substitute for lumbar spinal fusion. There was positive role of collagen as an adjunct for spinal bone fusion process.

Does minimally invasive fusion technique influence surgical outcomes in isthmic spondylolisthesis

Abstract Objective: To compare the clinical and radiographic results between open transforaminal interbody fusion (TLIF-O) and minimally invasive TLIF (TLIF-M) for single-level low grade isthmic spondylolisthesis (IS). Methods: This study enrolled 45 patients who underwent single-level TLIF with low grade IS. The patients were divided into two groups according to operative method: TLIF-M (20 patients) and TLIF-O (25 patients). TLIF-O group was matched with TLIF-M. Results: At one-year postoperatively, there were no significant differences in any radiologic parameters between the two groups. Perioperative results such as blood loss, operation time, and hospital stay were superior in TLIF-M than in TLIF-O. Fusion was achieved in 17 of 20 patients (85.0%) in TLIF-M and 23 of 25 (92.0%) patients in TLIF-O. Back Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores of TLIF-O were significantly lower than TLIF-M at one (back VAS, ODI) and six months (ODI) postoperatively. Conclusions: TLIF-M and TLIF-O produced similar clinical and radiological outcomes, including reduction of spondylolisthesis and disc space height restoration at one-year follow-up for single-level low grade IS. However, considering perioperative outcomes, back pain, and quality of life, TLIF-M might be a better option for single-level low grade IS compared to TLIF-O.

Surgical Outcomes After Segmental Limited Surgery for Adjacent Segment Disease: The Consequences of Makeshift Surgery

BACKGROUNDnTo minimize surgical morbidity, surgeons may opt to perform segmental limited surgery instead of fusion extension for adjacent segment disease (ASD) after lumbar fusion surgery. This study evaluated clinical outcomes from segmental limited surgery without fusion extension for ASD and assessed which clinical factors were associated with reoperation after segmental limited surgery.nnnMETHODSnMedical data of 50 patients who underwent segmental limited surgery for ASD after lumbar fusion surgery between 2005 and 2015 were reviewed. Demographic data, ASD type, preoperative disc and facet degeneration, ASD location, and surgical summary were collected. The primary outcome was reoperation rate at 24 months after surgery.nnnRESULTSnOf patients, 28 (56%) experienced recurrent radiculopathy (visual analog scale score ≥4). Revision surgery was performed in 22 patients (44%). Reoperation was performed more frequently in multilevel fusion first-surgery cases (15/23; 65.2%) than single-level fusion first-surgery cases (7/27; 25.9%; Pxa0= 0.005). The lowermost mobile segment group had a lower reoperation-free survival rate than the other group (hazard ratioxa0= 9.85, 95% confidence interval 1.32-73.54, Pxa0= 0.01 [log-rank]). The 2-year reoperation-free survival rate for the lowermost mobile segment group was 31.5%, whereas the rate for the other group was 83.3%.nnnCONCLUSIONSnSegmental limited surgery as a treatment for ASD after lumbar fusion surgery is likely to fail frequently and result in a high rate of recurrent radiculopathy and revision surgery. Fusion extension surgery is especially recommended for ASD at the lowermost mobile segment owing to the high failure rate.

Clinical relation among dural adhesion, dural ossification, and dural laceration in the removal of ossification of the ligamentum flavum

BACKGROUND CONTEXTnDural laceration frequently occurs during surgery in patients with ossification of the ligamentum flavum (OLF), mainly because of dural adhesion (DA) and dural ossification (DO) between the ligamentum flavum and the dura mater. However, the radiological predictive factors of DA in OLF have rarely been reported.nnnPURPOSEnThe objective of this study was to determine the preoperative radiological signs for predicting intraoperative DA in OLF by using preoperative magnetic resonance imaging (MRI) and computed tomography (CT).nnnSTUDY DESIGNnThis is a retrospective study.nnnPATIENT SAMPLEnThis study included 182 patients who underwent decompressive laminectomy and OLF removal from 2005 to 2014.nnnOUTCOME MEASUREnDemographic data, preoperative neurologic status, surgical procedure and results, and intraoperative and postoperative complications were analyzed. Clinical outcome was assessed with the Japanese Orthopaedic Association score.nnnMATERIALS AND METHODSnDepending on the morphologic appearance of OLF in preoperative radiographs, we aimed to investigate the prevalence of intraoperative DA and DO. We used the following factors of representative classifications: (1) surface appearance, (2) double-layer or tram-track sign, (3) cross-sectional area of the stenosed level, (4) Sato classification as axial classification, (5) Kuh classification as sagittal classification, and (6) high-signal-intensity change on T2-weighted MRI.nnnRESULTSnIntraoperative evidence of DA was observed in 52 patients (29%), and DO was observed in 23 patients (13%). Twenty-seven patients (15%) had dural laceration during surgery. Statistically, DA was closely associated with the non-uniform type of surface appearance (odds ratio 5.396, p=.001) and with the presence of either a double-layer sign or a tram-track sign (odds ratio 11.525, p<.001). In the preoperative CT and MRI, 21 out of 23 patients with DO showed a double-layer sign or a tram-track sign.nnnCONCLUSIONSnThis study identified two predictive factors of DA in OLF, which were the non-uniform surface appearance and the presence of a double-layer sign or a tram-track sign. The presence of DO in OLF was closely associated with a double-layer sign or a tram-track sign in the preoperative radiological images.