Normative data for neuromuscular assessment of the hand-arm vibration syndrome and its retrospective applications in Korean male workers.

PURPOSE: The purpose of this study was to describe normative data for the neuromuscular assessments of the hand-arm vibration syndrome (HAVS) in Korean. METHODS: Data for the vibrotactile perception threshold (VPT) at three frequencies (31.5, 125, and 250 Hz), the hand grip strength (HGS), the finger pinch strength (FPS), the finger tapping test, and the Purdue pegboard tests were collected from 120 male office workers aged 30-59 years with no prior history of regular use of handheld vibrating tools. The collected data were compared with the results of a similar study of shipbuilding workers in order to investigate the diagnostic utility of clinical test for HAVS. RESULTS: The mean VPT values indicate that no significant differences were observed between the dominant and non-dominant hands or between the index and little fingers. The age group of 30s was highly sensitive to vibration input with a peak in sensitivity at 125 Hz among all age groups. In neuromuscular performance, dominant hands are usually more accurate, dexterous, and functionally quicker than non-dominant hands. The index finger was superior to the little finger in the finger tapping counts (p < 0.05). Also, FPS was greater in the index finger than in the middle finger (p < 0.05). The HGS of dominant hands was significantly stronger than that of non-dominant hands (p < 0.05). When the normative data were compared with the data of shipyard workers exposed to vibration, there were statistically significant differences in VPT and neuromuscular functions. CONCLUSIONS: The current data can be used to evaluate HAVS in Korean male workers. Age is an important factor for VPT.

Computed tomography-guided percutaneous facet screw fixation in the lumbar spine. Technical note.

The authors describe a new minimally invasive technique for posterior supplementation using percutaneous translaminar facet screw (TFS) fixation with computed tomography (CT) guidance. Oblique axial images were used to determine facet screw fixation sites. After the induction of local anesthesia and conscious sedation, a guide pin was inserted and guided with a laser mounted on the CT gantry. Cannulated TFSs were placed via a percutaneous approach. From December 2002 to August 2003, 18 patients underwent CT-guided TFS. In 17 of these patients this procedure was supplementary to anterior lumbar interbody fusion, which had been performed several days earlier; in the remaining patient, CT-guided TFS fixation was undertaken as the primary therapy. Twelve patients had painful degenerative disc disease or unstable degenerative spondylolisthesis, three had infections, and three had deformities. All screws were inserted accurately and there were no complications. This new minimally invasive surgical technique may offer an alternative to pedicle screw fixation as a method of posterior supplementation.

Comparative radiologic evaluation of percutaneous endoscopic lumbar discectomy and open microdiscectomy: a matched cohort analysis.

BACKGROUND: Only a few studies comparing percutaneous endoscopic discectomy and open discectomy have been reported in the literature. The purpose of this study was to compare the radiographic changes in patients treated with percutaneous endoscopic lumbar discectomy (PELD) with those of patients treated with open lumbar microdiscectomy (OLM). METHODS: A total of 30 patients who underwent PELD with a minimum three years of follow-up were randomly selected. To compare with the PELD group, 30 patients who underwent OLM during the same period were also randomly selected according to sex, age, and disc level. The clinical outcomes were evaluated by the Macnab criteria. Statistical analysis was performed using independent sample t-test, paired sample t-test, chi-square test, Fisher's exact test, and analysis of variance (ANOVA). RESULTS: The successful clinical outcomes were 96.7% in the PELD group and 93.3% in the OLM group. Among the various radiological parameters, changes of disc height (1.41 +/- 1.19 mm in the PELD group and 2.29 +/- 2.12 mm in the OLM group, p=0.024) and foraminal height (1.26 +/- 0.91 mm in the PELD group and 1.85 +/- 0.92 mm in the OLM group, p=0.017) were significantly different between the two groups. CONCLUSIONS: Although the clinical outcomes were similarly satisfactory in both groups, PELD is a less invasive procedure than open microdiscectomy in s elected cases.

Immediate pain improvement is a useful predictor of long-term favorable outcome after percutaneous laser disc decompression for cervical disc herniation.

OBJECTIVE: The purpose of this study was to evaluate the long-term clinical outcome of percutaneous laser disc decompression (PLDD) for cervical disc herniation and to identify factors affecting long-term favorable outcome. BACKGROUND DATA: PLDD using the Ho:YAG laser has been regarded as an effective alternative for soft disc herniation. However, little is known about long-term favorable outcome parameters. METHODS: We retrospectively reviewed the clinical and radiological data of 60 patients who underwent PLDD with laser-assisted spinal endoscopy (LASE) for contained cervical soft disc herniation from January 1998 to January 2000. The clinical outcome was measured using the Macnab criteria. Statistical analysis was performed using Fisher's exact test. Sex, age, operated level and location of disc herniation, amount of laser energy, and time for symptom improvement were selected as parameters. RESULTS: The mean follow-up period was 71.0 months (range, 59-83 months). The mean age was 45.7 years (range, 26-68 years), and the mean symptom duration was 13.0 months (range, 2-60 months). The Visual Analogue Scale (VAS) score was significantly improved from 7.9 preoperatively to 2.6 at the final follow-up (p < 0.001). At the final follow-up, 51 (85.0%) patients achieved a favorable outcome. Immediate (within 24 h) pain relief was achieved in 19 patients, and it was strongly related to long-term success (p = 0.006). CONCLUSION: The long-term clinical outcome of PLDD with LASE was fairly good, with a success rate of 85%. Immediate pain relief is a useful prognostic factor predicting favorable outcome following the procedure.

Percutaneous endoscopic cervical discectomy: clinical outcome and radiographic changes.

OBJECTIVE: The purpose of this study was to evaluate the clinical outcome and radiographic changes of percutaneous endoscopic cervical discectomy (PECD) with the high-resolution working channel endoscope. BACKGROUND DATA: Percutaneous disc decompression using a laser and/or microforceps for cervical disc herniation has been regarded as an effective treatment modality in selected cases. However, the postoperative radiographic changes have not yet been evaluated. METHODS: We reviewed the clinical and radiographic records of 36 consecutive patients who underwent PECD with the working channel endoscope. The herniated discs were selectively removed by Ho:YAG laser and microforceps under high-resolution endoscopic visualization. The postoperative radiographic changes, including the disc height, the sagittal cervical alignment, and the segmental range of motion were measured. RESULTS: The mean follow-up period was 28.6 months (range, 23-34 months). Based on the Prolo Scale, excellent outcomes were achieved in 19 of 36 patients (52.8%), good outcomes in 12 (33.3%), fair outcomes in three (8.3%), and poor outcomes in two (5.6%). The disc height significantly decreased by 11.2% of the original height (p < 0.001). However, the overall and focal sagittal alignments were well maintained. There was no segmental instability or spontaneous fusion. One patient required subsequent open surgery due to incomplete decompression. CONCLUSIONS: The high-resolution working channel endoscope allowed us to selectively remove the cervical herniated disc. The postoperative disc height reduction was observed, with no significant effect on therapeutic success. The sagittal alignment and segmental motion were well preserved.

Cloning and characterization of rat neuronal apoptosis inhibitory protein cDNA.

The human neuronal apoptosis inhibitory protein (NAIP) gene was originally discovered because of its deletion in infantile spinal muscular atrophy (SMA), a childhood genetic disorder characterized by motor neuron loss and progressive paralysis with muscular atrophy. Although SMA is now known to be caused by deletions of survival motor neuron (SMN), the fact that NAIP is an anti-apoptotic protein is consistent with the NAIP gene modifying SMA severity. Here we report the cloning of a 1.5 kb rat NAIP cDNA fragment which contains BIR-3 (third baculovirus inhibitory repeat) domain. This fragment shows 78% homology to the human NAIP and 86% homology to the murine counterpart. We have investigated the distribution of NAIP mRNA expressing neurons by in situ RT-PCR technique in the rat central nervous system (CNS). Although all of the neurons appeared to express NAIP mRNA ubiquitously, pronounced elevation of NAIP mRNA expression was observed in the areas innervated by glutamatergic neurons after kainic acid (KA) injection. We have raised an anti-rat NAIP antiserum in rabbits using NAIP cDNA and recombinant rat NAIP, and carried out an immunohistological investigation. We observed highly immunoreactive neuronal subpopulations in the retinal ganglion, cerebral cortex, hippocampus, basal forebrain, thalamus, areas of midbrain, Purkinje cells of the cerebellum, and motor neurons in the spinal cord. Increased immunoreactivity of glutamatergic neurons was also observed broadly in the CNS after KA treatment. This study provides additional evidence that expression of mRNA and gene products of NAIP seem to be regulated in response to excessive stimuli or injuries in rat CNS, and these results are compatible with an anti-apoptotic role of NAIP in acute SMA as well as in brain injuries.

Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis.

BACKGROUND CONTEXT: Most surgeons have thought that posterior decompression is necessary to treat isthmic spondylolisthesis with leg pain. However, the surgical procedure not only requires wide muscle dissection but can also lead to spinal instability. The authors' treatment concept for isthmic spondylolisthesis is one-stage anterior reduction and posterior stabilization with minimally invasive surgical procedure without touching the spinal thecal sac and nerve. PURPOSE: To investigate a new surgical concept of minimally invasive anterior-posterior fusion without posterior decompression for the treatment of isthmic spondylolisthesis with leg pain. STUDY DESIGN: This is a retrospective study of 73 patients with isthmic spondylolisthesis who underwent minimally invasive anterior lumbar interbody fusion (mini-ALIF) followed by percutaneous pedicle screw fixation (PF) between October 2000 and February 2002. PATIENT SAMPLE: A total of 73 patients with low-grade isthmic spondylolisthesis (46 with Grade 1 and 27 with Grade 2) who underwent mini-ALIF followed by percutaneous PF were retrospectively analyzed. There were 20 men and 53 women, with a mean age of 50.6 (range, 19 to 77) years. All patients had low back pain and referred or radicular leg pain or neurogenic intermittent claudication in walking or standing. Average duration of symptoms was 26 (range, 3 to 120) months. OUTCOME MEASURES: The clinical outcome was graded according to the modified Macnab criteria. METHODS: The authors retrospectively reviewed clinical and radiological data of 73 patients who had isthmic spondylolisthesis. All patients underwent mini-ALIF and percutaneous PF on the same day between October 2000 and February 2002. The mean follow-up period was 16 months (range, 12 to 26). RESULTS: The mean operating time, blood loss and hospital stay were 210 minutes, 135 ml and 4.1 days, respectively. No blood transfusion was necessary. Clinical outcome was excellent in 26 patients (35.6%), good in 43 (58.9%), fair in 3 (4.1%) and poor in 1 (1.4%). The fusion rate was 97.3% (71 of 73). There were 6 cases (8.2%) of mini-ALIF complications and 6 (8.2%) of percutaneous PF complications. There were no postoperative neurologic deficits. CONCLUSIONS: Mini-ALIF followed by percutaneous PF is an efficacious alternative for low-grade isthmic spondylolisthesis, and posterior decompression is not necessary to relieve leg symptoms. This minimally invasive combined procedure offers many advantages, such as preservation of posterior arch, no nerve retraction, less blood loss, excellent cosmetic results, high fusion rate and early discharge.

Percutaneous endoscopic lumbar discectomy for migrated disc herniation: classification of disc migration and surgical approaches.

Percutaneous endoscopic lumbar discectomy (PELD) for migrated disc herniations is technically demanding due to the absence of the technical guideline. The purposes of this study were to propose a radiologic classification of disc migration and surgical approaches of PELD according to the classification. A prospective study of 116 consecutive patients undergoing single-level PELD was conducted. According to preoperative MRI findings, disc migration was classified into four zones based on the direction and distance from the disc space: zone 1 (far up), zone 2 (near up), zone 3 (near down), zone 4 (far down). Two surgical approaches were used according to this classification. Near-migrated discs were treated with "half-and-half" technique, which involved positioning a beveled working sheath across the disc space to the epidural space. Far-migrated discs were treated with "epiduroscopic" technique, which involved introducing the endoscope into the epidural space completely. The mean follow-up period was 14.5 (range 9-20) months. According to the Macnab criteria, satisfactory results were as follows: 91.6% (98/107) in the down-migrated discs; 88.9% (8/9) in the up-migrated discs; 97.4% (76/78) in the near-migrated discs; and 78.9% (30/38) in the far-migrated discs. The mean VAS score decreased from 7.5 +/- 1.7 preoperatively to 2.6 +/- 1.8 at the final follow-up (P < 0.0001). There were no recurrence and no approach-related complications during the follow-up period. The proposed classification and approaches will provide appropriate surgical guideline of PELD for migrated disc herniation. Based on our results, open surgery should be considered for far-migrated disc herniations.

An oblique paraspinal approach for intracanalicular disc herniations of the upper lumbar spine: technical case report.

OBJECTIVE: To present our experience of treating the central or paramedian disc herniations of the upper lumbar levels through a paraspinal approach. CLINICAL PRESENTATION: We present four patients with intracanalicular disc herniations at the L1-L2 or L2-L3 level. All patients had unilateral or bilateral radicular leg pain and motor weakness. TECHNIQUE: Considering the unique characteristics of the upper lumbar spine, we performed the oblique paraspinal approach to expose the central portion of disc and removed the herniated disc effectively. Postoperatively, their symptoms were improved. There was no instability during the follow-up period. CONCLUSION: The oblique paraspinal approach for the treatment of central disc herniations at the upper lumbar levels is an effective nonfusion technique that preserves most of the facet joint and provides a wide surgical field.

Operative failure of percutaneous endoscopic lumbar discectomy: a radiologic analysis of 55 cases.

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the range of lumbar disc herniation that can be addressed effectively using current endoscopic techniques. SUMMARY OF BACKGROUND DATA: The current technical limitation of the procedure in terms of the location and size of the herniation has not been fully documented in previous studies. METHODS: The inclusion was an intracanal lower lumbar disc herniation in which subsequent surgery was performed because of the presence of remnant fragments. All 1586 cases, including 55 failed cases, were classified according to the size, location, and extent of migration. RESULTS: In the nonmigrated herniations, the central located high-canal compromised (>50%) herniations showed the highest rate of failure (15%), and the rate was significantly different from the low and high-canal compromise group (1.9% and 11.1%, respectively, P < 0.001). There was no significant difference in the failure rate between the nonmigrated herniations and low-grade migration group (2.7% and 3.7%, respectively). However, the high-grade migration group (beyond the measured height of the posterior marginal disc space) showed a significantly high-incidence of failure (15.7%, P < 0.001). CONCLUSIONS: Based on these results, open surgery may be considered for herniations with high-canal compromise and high-grade migration. On the other hand, percutaneous endoscopic lumbar discectomy can be considered to be a surgical option in the remaining intracanal disc herniations.

Fluoroscopically assisted percutaneous translaminar facet screw fixation following anterior lumbar interbody fusion: technical report.

STUDY DESIGN: A technical report of fluoroscopically assisted percutaneous translaminar facet screw fixation after anterior lumbar interbody fusion (ALIF). OBJECTIVES: To describe a minimally invasive translaminar facet screw fixation technique that was modified from the Magerl method, and to assess its technical feasibility and clinical efficacy. SUMMARY OF BACKGROUND DATA: There is no previous study in the literature on percutaneous translaminar facet screw fixation assisted only by fluoroscopy without using any specially designed guiding device. Also, there is no previous study involving a screw insertion technique in which the screw is directed to purchase the pedicle while traversing the lamina and transfixing the facet joint. METHODS: A total of 20 patients with degenerative spinal disease underwent ALIF and supplementary percutaneous translaminar facet screw fixation under fluoroscopic guidance from 2001 through 2002. Their clinical and radiologic data were collected and analyzed. RESULTS: A total of 65 screws were inserted. Seven screws (10.8%) were found to have violated laminae walls but none injured or compressed neural structures directly. The purchases of the facet joints were all successful, but insertion into the pedicle in perfect position was successful in 55 screws (84.6%). Radiologic fusion occurred in all fused levels (100%). Estimated blood loss was 222.5 mL (100-520), and no blood transfusions were needed in any of the cases. There was only one complication related to facet screw fixation, in which the distal tip of a superior articular process was fractured caused by repeated drilling with a K-wire. CONCLUSIONS: Percutaneous translaminar facet screw fixation using fluoroscopy is technically feasible. It seems that the fluoroscopically assisted percutaneous translaminar facet pedicle screw fixation is a useful, minimally invasive posterior augmenting method following ALIF.

Percutaneous endoscopic lumbar discectomy for recurrent disc herniation: surgical technique, outcome, and prognostic factors of 43 consecutive cases.

STUDY DESIGN: A retrospective study of 43 consecutive patients who underwent percutaneous endoscopic lumbar discectomy for recurrent disc herniation. OBJECTIVES: To evaluate the efficacy of endoscopic discectomy for recurrent disc herniations and to determine the prognostic factors affecting surgical outcome. SUMMARY OF BACKGROUND DATA: Repeated open discectomy with or without fusion has been the most common procedure for a recurrent lumbar disc herniation. There have been no reports published on the feasibility and prognostic factors of the endoscopic discectomy for recurrent disc herniation. METHODS: The inclusion criteria were recurrent disc herniations at the same level, regardless of side, with a pain-free interval longer than 6 months after the conventional open discectomy. Posterolateral endoscopic laser-assisted disc excisions were performed under local anesthesia. RESULTS: The mean follow-up period was 31 months (24-39 months). Based on the MacNab criteria, 81.4% showed excellent or good outcomes. The mean visual analog scale decreased from 8.72 +/- 1.20 to 2.58 +/- 1.55 (P <0.0001). In our series, better outcomes were obtained in patients younger than 40 years (P = 0.035), patients with duration of symptoms of less than 3 months (P = 0.028), and patients without concurrent lateral recess stenosis (P = 0.007). CONCLUSIONS: Percutaneous endoscopic lumbar discectomy is effective for recurrent disc herniation in selected cases. The posterolateral approach through unscarred virgin tissue can prevent nerve injury and could preserve the spinal stability. Both foraminal and intracanalicular portions can be decompressed simultaneously.

FKBP-12 exhibits an inhibitory activity on calcium oxalate crystal growth in vitro.

Urolithiasis and calcium oxalate crystal deposition diseases are still significant medical problems. In the course of nephrocalcin cDNA cloning, we have identified FKBP-12 as an inhibitory molecule of calcium oxalate crystal growth. lambdagt 11 cDNA libraries were constructed from renal carcinoma tissues and screened for nephrocalcin cDNA clones using anti-nephrocalcin antibody as a probe. Clones expressing recombinant proteins, which appeared to be antigenically cross-reactive to nephrocalcin, were isolated and their DNA sequences and inhibitory activities on the calcium oxalate crystal growth were determined. One of the clone lambda gt 11 #31-1 had a partial fragment (80 bp) of FKBP-12 cDNA as an insert. Therefore, a full-length FKBP-12 cDNA was PCR-cloned from the lambda gt 11 renal carcinoma cDNA library and was subcloned into an expression vector. The resultant recombinant FKBP-12 exhibited an inhibitory activity on the calcium oxalate crystal growth (Kd=10(-7) M). Physiological effect of the extracellular FKBP-12 was investigated in terms of macrophage activation and proinflammatory cytokine gene induction. Extracellular FKBP-12 failed to activate macrophages even at high concentrations. FKBP-12 seems an anti-stone molecule for the oxalate crystal deposition disease and recurrent stone diseases.