Chae-Gwan Kong

The increased expression of matrix metalloproteinases associated with elastin degradation and fibrosis of the ligamentum flavum in patients with lumbar spinal stenosis.

Background One of the characteristics of spinal stenosis is elastin degradation and fibrosis of the extracellular matrix of the ligamentum flavum. However, there have been no investigations to determine which biochemical factors cause these histologic changes. So we performed the current study to investigate the hypothesis that matrix metalloproteinases (MMPs), which possess the ability to cause extracellular matrix remodeling, may play a role as a mediator for this malady in the ligamentum flavum. Methods The ligamentum flavum specimens were surgically obtained from thirty patients with spinal stenosis, as well as from 30 control patients with a disc herniation. The extents of ligamentum flavum elastin degradation and fibrosis were graded (grade 0-4) with performing hematoxylin-eosin staining and Massons trichrome staining, respectively. The localization of MMP-2 (gelatinase), MMP-3 (stromelysin) and MMP-13 (collagenase) within the ligamentum flavum tissue was determined by immunohistochemistry. The expressions of the active forms of MMP-2, MMP-3 and MMP-13 were determined by western blot analysis, and the blots were quantified using an imaging densitometer. The histologic and biochemical results were compared between the two conditions. Results Elastin degradation and fibrosis of the ligamentum flavum were significantly more severe in the spinal stenosis samples than that in the disc herniation samples (3.14 ± 0.50 vs. 0.55 ± 0.60, p < 0.001; 3.10 ± 0.57 vs. 0.76 ± 0.52, p < 0.001, respectively). The expressions of the active form of MMPs were identified in all the ligamentum flavums of the spinal stenosis and disc herniation patients. The expressions of active MMP-2 and MMP-13 were significantly higher in the spinal stenosis samples than that in the disc herniation samples (both p < 0.05). The expression of active MMP-3 was slightly higher in the spinal stenosis samples than that in the disc herniation samples, but the difference was not statistically significant (p = 0.131). MMP-2, -3, and -13 were positively stained on the ligamentum flavum fibroblasts. Conclusions The current results suggest that the increased expression of active MMPs by the ligamentum flavum fibroblasts might be related to the elastin degradation and fibrosis of the ligamentum flavum in the patients who suffer with lumbar spinal stenosis.

Inter- and Intra-observer Variability of a Cervical OPLL Classification Using Reconstructed CT Images

Background The lateral radiograph-based system described by Tsuyama is used widely to classify ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. However, OPLL is a complex 3-dimensional (3-D) lesion, not a simple and uniplanar one, which is often difficult to identify on a lateral radiograph. Furthermore, its reliability among spine surgeons has not been investigated. Given the popularity of a reconstructed computed tomography (CT), this study examined the inter- and intra-observer reliability of lateral radiograph-based OPLL classification using that modality. Methods Five spine surgeons independently reviewed the lateral radiograph, axial CT, 2-D (sagittal) and 3-D reconstructed CT images of 108 OPLL patients on 2 separate occasions. Based on these images, the reviewers classified each OPLL case according to the Tsuyamas system. The kappa values were used to assess the statistical reliability. Results The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images. Conclusions The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images.

High Glucose Accelerates Autophagy in Adult Rat Intervertebral Disc Cells

Study Design In vitro cell culture. Purpose The purpose of this study was to investigate the effect of high glucose on autophagy in adult rat intervertebral disc cells. Overview of Literature Diabetes mellitus is considered to be an important etiologic factor for intervertebral disc degeneration, resulting in degenerative disc diseases. A glucose-mediated increase of autophagy is a major causative factor for the development of diseases associated with diabetes mellitus. However, no information is available for the effect of high glucose on autophagy in adult intervertebral disc cells. Methods Nucleus pulposus and annulus fibrosus cells were isolated from 24-week-old adult rats, cultured and placed in either 10% fetal bovine serum (normal control) or 10% fetal bovine serum plus two different high glucose concentrations (0.1 M and 0.2 M) (experimental conditions) for one and three days, respectively. The expressions of autophagy markers, such as beclin-1, light chain 3-I (LC3-I) and LC3-II, autophagy-related gene (Atg) 3, 5, 7 and 12, were identified and quantified. Results Two high glucoses significantly increased the expressions of beclin-1, LC3-II, Atg3, 5, 7, and 12 in adult rat nucleus pulposus and annulus fibrosus cells in a dose- and time-dependent manner. The ratio of LC3-II/LC3-I expression was also increased in a dose-respectively time-dependent manner. Conclusions The results suggest that autophagy of adult nucleus pulposus and annulus fibrosus cells might be a potential mechanism for the intervertebral disc degeneration in adult patients with diabetes mellitus. Thus, the prevention of autophagy in adult intervertebral disc cells might be considered as a novel therapeutic target to prevent or to delay the intervertebral disc degeneration in adult patients with diabetes mellitus.

Postoperative Urinary Retention Following Anterior Cervical Spine Surgery for Degenerative Cervical Disc Diseases

Background Postoperative urinary retention (POUR) may cause bladder dysfunction, urinary tract infection, and catheter-related complications. It is important to be aware and to be able to identify patients at risk of developing POUR. However, there has been no study that has investigated the incidence and risk factors for the development of POUR following anterior cervical spine surgery for degenerative cervical disc disease. Methods We included 325 patients (164 male and 161 female), who underwent anterior cervical spine surgery for cervical radiculopathy or myelopathy due to primary cervical disc herniation and/or spondylosis, in the study. We did not perform en bloc catheterization in our patients before the operation. Results There were 36 patients (27 male and 9 female) that developed POUR with an overall incidence of 11.1%. The mean numbers of postoperative in-and-out catheterizations was 1.6 times and mean urine output was 717.7 mL. Thirteen out of 36 POUR patients (36%) underwent indwelling catheterization for a mean 4.3 days after catheterization for in-and-out surgery, because of persisting POUR. Seven out of 36 POUR patients (19%) were treated for voiding difficulty, urinary tract irritation, or infection. Chi-square test showed that patients who were male, had diabetes mellitus, benign prostate hypertrophy or myelopathy, or used Demerol were at higher risk of developing POUR. The mean age of POUR patients was higher than non-POUR patients (68.5 years vs. 50.8 years, p < 0.01). Conclusions To avoid POUR and related complications as a result of anterior cervical spine surgery for degenerative cervical disc disease, we recommend that a catheter be placed selectively before the operation in at-risk patients, the elderly in particular, male gender, diabetes mellitus, benign prostate hypertrophy, and myelopathy. We recommend that Demerol not be used for postoperative pain control.

Sacralization of L5 in Radiological Studies of Degenerative Spondylolisthesis at L4-L5

Study Design Radiological analysis. Purpose To investigate sacralization of L5 on radiological studies of degenerative spondylolisthesis at L4-L5. Overview of Literature Degenerative spondylolisthesis commonly develops at L4-L5. Sacralization of L5 is thought to cause stress concentration at this level, which accentuates degenerative changes and promotes development of degenerative spondylolisthesis. However, there has been no study dedicated to determining whether the presence of sacralization at L5 influences the radiological findings in degenerative spondylolisthesis at L4-L5. Methods Seventy-eight patients with degenerative spondylolisthesis at L4-L5 were classified into two groups according to the presence of L5 sacralization: with (n=54) and without (n=24). Four radiographic parameters were measured and compared between the two groups: anterior slippage of L4 on L5 (% slip), facet orientation of L4-L5 (degrees), facet osteoarthritis of L4-L5 by Fujiwaras criteria (1~4 grades), and disc degeneration of L4-L5 by Frymoyers criteria (grades 1~5). Results There was no significant difference in the degree of anterior slippage of L4 on L5 (17.02±6.21 versus 16.65±4.87, p=0.809), facet orientation (54.99±12.18 versus 56.23±4.35, p=0.642), facet osteoarthritis (3.43±0.59 versus 3.53±0.37, p=0.527), or disc degeneration (4.50±0.51 versus 4.35±0.61, p=0.340) between the two groups. Conclusions Our study shows that the influence of sacralization of L5 on radiological findings in degenerative spondylolisthesis at L4-L5 may be less significant than previously expected. Further studies in large patient groups are needed to clarify the role of L5 sacralization on the development of degenerative spondylolisthesis at L4-L5.

Patellar tracking after total knee arthroplasty performed without lateral release

There is limited clinical data on patellar maltracking in patients who have undergone total knee arthroplasty (TKA) without lateral release. We performed a retrospective review of 191 consecutive TKAs performed by one surgeon through the subvastus approach without lateral release from 2007 to 2008. Radiographic measurements were made using the preoperative and postoperative 2 years radiographs. Multivariate logistic regression analysis was performed to determine the risk factors for patellar maltracking after TKA performed without lateral release. TKA resulted in increases in the patellar tilt and displacement (P<0.05). The presence of preoperative patellar tilt and displacement were predictive of postoperative patellar tilt and displacement in patients who underwent TKA through the subvastus approach without lateral release (P<0.05).

Postoperative changes of early-phase inflammatory indices after uncomplicated anterior cervical discectomy and fusion using allograft and demineralised bone matrix

PurposesWe investigated sequential levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in uncomplicated ACDF (anterior cervical discectomy and fusion) using allograft and DBM (demineralised bone matrix) for primary cervical spondylosis and/or disc herniation. To our knowledge, there has been no study to investigate the diagnostic value of CRP and ESR for postoperative infection in ACDF using allograft and DBM.MethodsBlood samples of 85 patients, who underwent one- (n = 51) or two-level (n = 34) ACDF, were obtained and evaluated before surgery and on the first, third, fifth, seventh, 14th, 30th, and 90th postoperative days. No infection was found in any patient for at least one year follow-up period.ResultsMean CRP value increased significantly on the first postoperative day and reached a peak on the third postoperative day. The peak level rapidly decreased but remained elevated on the fifth, seventh, and 14th postoperative days. Mean ESR value increased significantly and reached a peak on the third postoperative day. The peak level gradually decreased but remained elevated on the fifth and seventh postoperative days. One- and two-level ACDF exhibited similar postoperative changes in CRP and ESR values and no significant difference in mean levels of CRP and ESR throughout the follow-up periods.ConclusionsThis study demonstrates that uncomplicated ACDF using allograft and DBM showed significant abnormal values of CRP and ESR during the early postoperative period. This result suggests that abnormal values of CRP and ESR in the early postoperative period do not indicate acute postoperative infection after ACDF using allograft and DBM. Straying from the normal course, such as a second rise or a failure to decrease, of CRP and ESR is more important to signpost acute postoperative infection in ACDF using allograft and DBM.

Avulsion fracture of the iliac crest apophysis treated with open reduction and internal fixation.

We report a case involving an avulsion fracture of the iliac crest apophysis in a 16-year-old boy. Occasionally, apophyseal avulsion fractures of the pelvis occur; however, those that occur at the iliac crest are rare. As a result of the large size of the fracture fragment and marked displacement (more than 3 cm), the fracture was managed operatively with open reduction and internal fixation. The patient returned to preinjury physical activity levels 2 months after surgery without complication.

Arteriovenous fistula of the superior gluteal artery as a complication of posterior iliac crest bone graft harvesting: 3D-CT angiography and arterial embolization

Superior gluteal artery injuries are rare, but potentially serious complications that occur during posterior iliac crest bone graft harvesting. The authors reported an arteriovenous fistula of the superior gluteal artery, which occurred as a complication during posterior iliac crest bone graft harvesting and was diagnosed with 3D-CT angiography, then treated with arterial embolization.

Diagnostic Usefulness of White Blood Cell and Absolute Neutrophil Count for Postoperative Infection after Anterior Cervical Discectomy and Fusion Using Allograft and Demineralized Bone Matrix

Study Design Prospective study. Purpose We investigated normative temporal levels of white blood cell (WBC) and absolute neutrophil count (ANC) in uncomplicated anterior cervical discectomy and fusion (ACDF) using allograft and demineralized bone matrix (DBM). Overview of Literature No study has investigated the diagnostic usefulness of WBC and ANC for postoperative infection following ACDF using allograft and DBM. Methods Blood samples of 85 patients, who underwent one or two-level ACDF, were obtained and evaluated before surgery and on the first, third, fifth, seventh, fourteenth, thirtieth, and ninetieth postoperative days. No infection was found in all patients for at least one year follow-up period. Results Mean WBC and ANC values increased significantly and reached peak levels on the first postoperative day. The peaked levels rapidly decreased but still remained elevated above the preoperative levels on the third postoperative day. The levels returned close to the preoperative levels on the fifth postoperative day. The mean WBC and ANC values did not get out of their normal reference ranges throughout the follow-up periods. One-level and two-level ACDF exhibited a similar course of postoperative changes in WBC and ANC values and no significant difference in mean levels of WBC and ANC throughout the follow-up periods. Conclusions Uncomplicated ACDF using allograft and DBM showed normal values of WBC and ANC during the early postoperative period. Therefore, significant abnormal values of WBC and ANC at an early postoperative period suggest the possibility of the development of acute postoperative infection after ACDF using allograft and DBM.