The Clinical Characteristics of Lower Lumbar Osteoporotic Compression Fractures Treated by Percutaneous Vertebroplasty : A Comparative Analysis of 120 Cases

OBJECTIVE: The purpose of this study is to provide accurate understanding of clinical presentations and surgical outcomes as well as to identify the unique characteristics of lower lumbar osteoporotic compression fracture (OCF). METHODS: Clinical data were collected from 120 patients who had L3, L4 or L5 percutaneous vertebroplasty (PVP) performed from 2008 to 2012 at the single institute. L4 or L5 PVP patients were classified into group 1 and group 2 was for L3 PVP patients. Medical records were retrospectively investigated at 1 month after PVP. Long term follow-up results were obtained at a median value of 22 months after PVP. RESULTS: 75% of the patients in group 1 were not associated with traumatic events, 71% presenting with leg radiating symptoms and 46% requiring an additional decompressive surgery, more often than those in group 2. These differences are statistically significant (p<0.05). The short term medical record review demonstrated that only 73% of patients in group 1 were ameliorated with regard to back motion pain, whereas those in group 2 reported 87.7% rates of amelioration in identical category (p<0.05). The long term follow up confirmed a significantly worse outcome in group 1, with only 55.7% of patients reporting amelioration in their pain or functional status, but 71.7% rate of amelioration in group 2. CONCLUSION: The OCFs at the L4 or L5 level have different clinical characteristics from those at upper levels of the lumbar spine.

Unilateral Posterior Atlantoaxial Transarticular Screw Fixation in Patients with Atlantoaxial Instability : Comparison with Bilateral Method

OBJECTIVE: Bilateral C1-2 transarticular screw fixation (TAF) with interspinous wiring has been the best treatment for atlantoaxial instability (AAI). However, several factors may disturb satisfactory placement of bilateral screws. This study evaluates the usefulness of unilateral TAF when bilateral TAF is not available. METHODS: Between January 2003 and December 2007, TAF was performed in 54 patients with AAI. Preoperative studies including cervical x-ray, three dimensional computed tomogram, CT angiogram, and magnetic resonance image were checked. The atlanto-dental interval (ADI) was measured in preoperative period, immediate postoperatively, and postoperative 1, 3 and 6 months. RESULTS: Unilateral TAF was performed in 27 patients (50%). The causes of unilateral TAF were anomalous course of vertebral artery in 20 patients (74%), severe degenerative arthritis in 3 (11%), fracture of C1 in 2, hemangioblastoma in one, and screw malposition in one. The mean ADI in unilateral group was measured as 2.63 mm in immediate postoperatively, 2.61 mm in 1 month, 2.64 mm in 3 months and 2.61 mm in 6 months postoperatively. The mean ADI of bilateral group was also measured as following; 2.76 mm in immediate postoperative, 2.71 mm in 1 month, 2.73 mm in 3 months, 2.73 mm in 6 months postoperatively. Comparison of ADI measurement showed no significant difference in both groups, and moreover fusion rate was 100% in bilateral and 96.3% in unilateral group (p=0.317). CONCLUSION: Even though bilateral TAF is best option for AAI in biomechanical perspectives, unilateral screw fixation also can be a useful alternative in otherwise dangerous or infeasible cases through bilateral screw placement.

Indirect decompression as a minimally invasive spine surgery / 한양의대학술지

The purpose of this study is to introduce the various methods of indirect decompression of minimally invasive procedures available for treatment of lumbar spine surgery. A review of the literature, as well as our personal experience with minimally invasive approaches to the lumbar discs, was performed. The minimally invasive procedures for treatment of lumbar disc disease include the following: 1) chemonucleolysis; 2) automated percutaneous lumbar discectomy (APLD); 3) nucleoplasty; 4) microdecompressor; 5) percutaneous laser discectomy; and 6) hydrodiscectomy. Although all percutaneous techniques are reported to have high success rates, to date no studies have demonstrated any of these being superior to microsurgical discectomy, which continues to be regarded as the standard with which all other techniques must be compared.

Subsidence of Cylindrical Cage (AMSLUTM Cage): Postoperative 1 Year Follow-up of the Cervical Anterior Interbody Fusion

OBJECTIVE: There are numerous reports on the primary stabilizing effects of the different cervical cages for cervical radiculopathy. But, little is known about the subsidence which may be clinical problem postoperatively. The goal of this study is to evaluate subsidence of cage and investigate the correlation between radiologic subsidence and clinical outcome. METHODS: To assess possible subsidence, the authors investigated clinical and radiological results of the onehundred patients who underwent anterior cervical fusion by using AMSLUTM cage during the period between January 2003 and June 2005. Preoperative and postoperative lateral radiographs were measured for height of intervertebral disc space where cages were placed. Intervertebral disc space was measured by dividing the sum of anterior, posterior, and midpoint interbody distance by 3. Follow-up time was 6 to 12 months. Subsidence was defined as any change in at least one of our parameters of at least 3 mm. RESULTS: Subsidence was found in 22 patients (22%). The mean value of subsidence was 2.21 mm, and mean subsidence rate was 22%. There were no cases of the clinical status deterioration during the follow-up period. No posterior or anterior migration was observed. CONCLUSION: The phenomenon of subsidence is seen in substantial number of patients. Nevertheless, clinical and radiological results of the surgery were favorable. An excessive subsidence may result in hardware failure. Endplate preservation may enables us to control subsidence and reduce the number of complications.

Myelopathy Caused by Soft Cervical Disc Herniation: Surgical Results and Prognostic Factors

OBJECTIVE: The purpose of this study was to investigate the surgical results and prognostic factors for patients with soft cervical disc herniation with myelopathy. METHODS: During the last 7 years, 26 patients with cervical discogenic myelopathy were undertaken anterior discectomy and fusion. Clinical and radiographic features were reviewed to evaluate the surgical results and prognostic factors. The clinical outcome was judged using two grading systems (Herkowitz's scale and Nurick's grade). RESULTS: Male were predominant (4:1), and C5-6 was the most frequently involved level. Gait disturbance, variable degree of spasticity, discomfort in chest and abdomen, hand numbness were the most obvious signs. Magnetic resonance(MR) images showed that central disc herniation was revealed in 16 cases, and accompanying cord signal changes in 4. Postoperatively, 23 patients showed favorable results (excellent, good and fair) according to Herkowitz's scale. CONCLUSION: Anterior cervical discectomy and fusion effectively reduced myelopathic symptoms due to soft cervical disc herniation. The authors assured that the shorter duration of clinical attention, the lesser the degree of myelopathy and better outcome in discogenic myelopathy.

A Multi-center Clinical Study of Posterior Lumbar Interbody Fusion with the Expandable Stand-alone Cage (Tyche(R) Cage) for Degenerative Lumbar Spinal Disorders

OBJECTIVE: This multi-center clinical study was designed to determine the long-term results of patients who received a one-level posterior lumbar interbody fusion with expandable cage (Tyche(R) cage) for degenerative spinal diseases during the same period in each hospital. METHODS: Fifty-seven patients with low back pain who had a one-level posterior lumbar interbody fusion using a newly designed expandable cage were enrolled in this study at five centers from June 2003 to December 2004 and followed up for 24 months. Pain improvement was checked with a Visual Analogue Scale (VAS) and their disability was evaluated with the Oswestry Disability Index. Radiographs were obtained before and after surgery. At the final follow-up, dynamic stability, quality of bone fusion, interveretebral disc height, and lumbar lordosis were assessed. In some cases, a lumbar computed tomography scan was also obtained. RESULTS: The mean VAS score of back pain was improved from 6.44 points preoperatively to 0.44 at the final visit and the score of sciatica was reduced from 4.84 to 0.26. Also, the Oswestry Disability Index was improved from 32.62 points preoperatively to 18.25 at the final visit. The fusion rate was 92.5%. Intervertebral disc height, recorded as 9.94+/-2.69 mm before surgery was increased to 12.23+/-3.31 mm at postoperative 1 month and was stabilized at 11.43+/-2.23 mm on final visit. The segmental angle of lordosis was changed significantly from 3.54+/-3.70 degrees before surgery to 6.37+/-3.97 degrees by 24 months postoperative, and total lumbar lordosis was 20.37+/-11.30 degrees preoperatively and 24.71+/-11.70 degrees at 24 months postoperative. CONCLUSION: The re have been no special complications regarding the expandable cage during the follow-up period and the results of this study demonstrates a high fusion rate and clinical success.

Observation between Clinical Outcomes and the Size of the Syrinx with Magnetic Resonance Image

OBJECTIVE: This study was conducted to examine the correlation between clinical outcomes and the size of the syrinx in post-operative magnetic resonance imaging(MRI) and symptom duration. METHODS: The authors investigated twelve patients who underwent various operations for syringomyelia from January 1995 to December 2003. The authors retrospectively analyzed medical records, pre- and post-operative MRI findings, features and durations of symptoms, and the method of surgical treatments. The clinical outcomes were assessed on Prolo scale at 6 months of post-operative period. RESULTS: Neurologic symptoms did not promptly disappear after the shrinkage of syrinx, but post-operative MRI demonstrated most patients showed reductions in the size of the syrinx. There is no statistical relationship between clinical improvements and decrements of the syrinx size. However, patients who underwent surgical treatment within 2 years from the symptom onset had more favorable outcome than those who had operations after 2 years from the onset of symptoms. CONCLUSION: Change in the size of the syrinx in post-operative MRI is not directly proportional to favorable clinical outcomes. However, symptom duration before surgical treatment has considerable impact on the clinical outcomes.

Surgical Treatment of Lumbar Spinal Stenosis in Geriatric Population: Is It Risky?

OBJECTIVE: Lumbar spinal stenosis is increasingly recognized as a common cause of low back pain in elderly patients. Conservative treatment has been initially applied to elderly patients, however, surgical treatment is sometimes indispensable to relieve severe pain. We retrospectively examine the age-related effects on the surgical risk, and results following general anesthesia and operative procedure in geriatric patients for two different age groups of at least 65years old. METHODS: Consecutive 51patients (> or = 65years), who underwent open surgical procedure for degenerative lumbar spinal stenosis, were selected in the study. Patients were divided into two groups. Group A included all patients who were between 65 and 69years of age at the time of surgery. Group B included all patients who were at least 70years of age at the time of surgery. We reviewed medical history including preoperative American Society of Anesthesiologists(ASA) classification of physical status, anesthetic risk factor, operative time, estimated blood loss, transfusion requirements, hospital stay, operated level, and clinical outcome to look for comparisons between two age groups (65~69 and over 70years). RESULTS: In preoperative evaulation, mean anesthetic risk factor of patients was numerically similar between the groups. The American Society of Anesthesiologists classification of physical status was similar between two groups. There was no difference in operated level, operative time, estimated blood loss, hospital stay, and anesthetic risk factor between the two groups. The clinical successful outcome showed 82.7% for Group A and 81.8% for group B. The overall postoperative complication rates were similar for both group A and B. CONCLUSION: We conclude that advanced age per se, did not increase the associated morbidity and mortality in surgical decompression for spinal stenosis.

Wedge Shape Cage in Posterior Lumbar Interbody Fusion: Focusing on Changes of Lordotic Curve

OBJECTIVE: Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. METHODS: We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. RESULTS: Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was 1.96? Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. CONCLUSION: Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

Radiologic Evaluation of Proper Pedicle Screw Placement after Pedicle Screw Fixation in Degenerative Lumbar Disc Disease

OBJECTIVE: With the increasing popularity of pedicle screw fixation devices for several indications, the safety and reliability of screw insertion in the small pedicle has become a major issue. Many studies have investigated the accuracy of screw placement after pedicle screw fixation using various method. The reported displacement rates have been very different. The purpose of the study is to investigate the proper placement of pedicle screw insertion in the lumbar spine on 26 consecutive patients. METHODS: Between September and December 2003, 26 consecutive patients (16women and 10men) were analyzed after transpedicular screw fixation of the lumbar and lumbosacral spine. After pedicle screw fixation in this study, 2-mm slices of CT scan were performed in all patients to detect caudal and cranial deviation of screw and medial and lateral deviation. Pedcile screw placement related complication was evaluted clinically. RESULTS: A total of 144 inserted pedicle were analyzed in 26patients, and 58pedicle screws (40.3%) were detected to be improper placement. There were 14level (9.0%) of caudal or cranial deviation and 44level (30.6%) of medial or lateral deviation to the pedicle. Extra-pedicle placement was found on 4levels (2.7%) with only 1case of neurologic injury. CONCLUSION: Proper screw placement, though complication rate is low, is important not only for clinical symptom but also for biomechanics. Further study for screw placement related biomechanical changes is needed.

Biomechanical Testing of Anterior Cervical Spine Implants: Evaluation of Changes in Strength Characteristics and Metal Fatigue Resulting from Minimal Bending and Cyclic Loading

OBJECTIVE: To achieve optimal fit of implant, it is necessary to bend the implant during spine surgery. Bending procedure may decrease stiffness of plate especially made of titanium and stainless steel. Typically titanium suffers adverse effects including early crack propagation when it is bent. We investigate whether 6 degree bending of titanium plates would decrease the stiffness after full cyclic loading by comparing with non-bending titanium plates group. METHODS: Authors experimented 40 titanium alloy plates of 57mm in length, manufactured by 5 different companies. Total 40 plates were divided into two groups (20 bent plates for experimental group and 20 non-bent plates for control group). Twenty plates of experimental group were bent to 6 degree with 3-point bending technique and verified with image analyzer. Using the electron microscope, we sought for a initial crack before and after 3-point bending. Mechanical testing by means of 6000 cyclic axial-compression loading of 35N in compression with moment arm of 35mm-1.1Nm was conducted on each plate and followed by the electron microscopic examination to detect crack or fissure on plates. RESULTS: The stiffness was decreased after 6000 cyclic loading, but there was no statistically significant difference in stiffness between experimental and control group. There was no evidence of change in grain structure on the electron microscopic magnification. CONCLUSION: The titanium cervical plates can be bent to 6 degree without any crack or weakness of plate. We also assume that minimal bending may increase the resistance to fatigue fracture in cervical flexion-extension movement.

Is Magnetic Resonance Image Alone Sufficient for Detecting Disc Cyst?

Disc cyst is an exaggerated form of disc degeneration that requires discography to confirm diagnosis. A case of 25-year-old man with back pain and left thigh numbness is described. A juxtaradicular extradural cyst at the upper lumbar spine, straddled the intervertebral foramen and migrated superiorly, was depicted as a bean-shaped high signal lesion that connected to the corresponding disc via a low signal stalk on T2-weighted magnetic resonance images. Gadolinium-enhanced images showed faint peripheral enhancement. Surgical specimen was histologically confirmed as a pseudocyst and he made a full recovery. We are able to detect a disc cyst with magnetic resonance imaging, particularly Gadolinium-enhanced and sagittal T2-weighted images, which was possible in the past only with invasive discography.

Acute New Compression Fractures of Consecutive Vertebral Bodies Adjacent to the Previously Augmented Level with Kyphoplasty

We report two cases of consecutive 3 level compression fractures in two female previously treated for 1 level osteoporotic compression fracture with kyphoplasty after 1 month and 2 weeks, respectively. First patient showed T12, L1, L2 level compression fractures after kyphoplasty on L3, and second patient showed L2, L4, L5 level fractures after same prcedure on L3. Any other specific pathologic lesions were not seen on bone scan. Bone mineral density (BMD) showed severe osteoporsis of multiple levels. We suggest that patients with severe osteoporosis must be thoroughly informed of this infrequent, albeit troblesome acute new compression fractures adjacent to the previously augmented level occurred following such a short period of kyphoplasty.

Short-term Results of Anterior Cervical Fusion with Cylindrical Cage(AMSLU(TM))

OBJECTIVE: The AMSLU(TM) cage is a newly developed instrument, that utilizes concept of the key-stone graft in posterior lumbar interbody fusion. The authors try to prove the short-term efficacy of AMSLU(TM) cage in surgical treatment of degenerative cervical disc disease. METHODS: We investigate clinical and radiological features of 24 patients who underwent anterior cervical fusion with AMSLU(TM) cage during the period between January 2001 and February 2002. Clinical and radiological results were assessed by using Odom's criteria and regular follow-up of radiographs, respectively. RESULTS: All patients included in this study had been followed by at least 6 months. Except 3 patients, all patients underwent single-level operation, and among remaining 21 patients, C5-6 was the most commonly involved level (17 cases). Symptomatic improvement was found in 22 cases (91%). Evidence of bone fusion was invariably found by the end of the postoperative 6 months in every case and increase of disc height was also shown in all patients. Neither operation-related nor instrument-related complications was seen. CONCLUSION: Anterior cervical fusion with AMSLU(TM) cage has several advantages over the preexisting instruments, such as easy maneurability, avoidance of donor site complications, and anatomical contour which renders it to endure lateral shearing force and its relatively large contact area.

Influence of Routine Intraoperative Ventricular Drainage on the Incidence of Aneurysmal Rebleeding

OBJECTIVE: Although there are several risk factors to which related intraoperative aneurymal bleeding, the relationship between ventricular drainage to aneurysmal rebleeding is still controversial. We investigate to define the relationship of an immediate ventricular drainage after craniotomies in predissection stage rerupture of aneurysms. METHODS: Randomized prospective and retrospective analyses were performed on 197 consecutive patients with confirmed aneurysmal subarachnoid hemorrhage(SAH) who underwent aneurysmal clipping in acute stage during 5 years. The aneurysmal SAH patients were divided into two groups according to the use of intraoperative ventricular cerebrospinal fluid(CSF) drainage. Various variables including Hunt-Hess grade, Fisher grade, Glasgow coma scale, Glasgow outcome scale, location of aneurysms, and the presence of a "daughter" aneurysm and hydrocephalus were analyzed. RESULTS: Regardless the drained CSF amount, the incidence of the intraoperative aneurysmal rerupture in predissection stage during aneurysmal clipping has not showed any difference in both groups. Depending on the presence of the acute hydrocephalus, the rerupture incidence in dissection stage during aneurysmal surgery was not statistically significant. However, the frequency of rebleeding in patients with ventriculostomy(66% of 24) was significantly higher than in hydrocephalic patients without ventriculostomy(25% of 27) and patients without acute hydrocephalus(22% of 110). CONCLUSION: Routine intraoperative ventricular drainage does not increase the incidence of aneurysmal rebleeding and the more extensive arachnoid dissection is not necessary even during an early surgery. Moreover, it obtains an adequate intraoperative brain relaxation, which resulted in the decrease of retraction injury.

Cervical Epidural Abscess Secondary to Aorto-Duodenal Fistula: A Case Report

Although cervical epidural abscess is rare, it should be strongly suspected in any patient with unexplainable neck pain and fever, especially when the patient has a predisposing factor for this infectious process. The authors report a case of cervical epidural abscess in a 39-yr-old man with an aorto-duodenal fistula, which complicated the interposition of artificial graft for abdominal aortic aneurysm rupture, which had undertaken 40 months before. Timely detection and intervention rendered him a full neurological recovery. This extremely rare case is presented with a literature review.

Dysphagia Caused by Ossification of the Cervical Anterior Longitudinal Ligament

We report a case of cervical ossification of the anterior longitudinal ligament(OALL) that contributed to dysphagia with ossification of posterior longitudinal ligament. A 63-year-old man complained of progressive dysphagia for solid foods. Clinical and radiographical findings including barium esophagogram and computed tomography showed OALL in cervical vertebrae from C2 to C7. Magnetic resonance images demonstrated displacement of the trachea and esophagus by OALL. The patient underwent anterior ostectomy from C2 to C7 via anterior cervical approach with excellent relief of dysphagia.

Cervical Myelopathy Due to Calcification of Ligamentum Flavum at the Atlantoaxial Junction: Case Report

The authors report a very rare case of marked segmental stenosis of the atlantoaxial junction causing cervical myelopathy. A 53-year-old woman suffered from burning paresthesia of both upper extremities and progressive gait disturbance for 3 years. Magnetic resonance images showed that spinal cord was markedly compressed due to hypertrophied and calcified ligamentum flavum at the atlantoaxial junction. She made a full recovery following decompressive laminectomy of atlas and axis. A posterior decompression may constitute adequate treatment and provide neurological improvement.

Intraventricular Vancomycin Instillation for Postcraniotomy Ventriculitis

OBJECTIVE: To evaluate the efficiencies, shortcomings and complications of intraventricular(IVT) vancomycin instillation for controlling the postcraniotomy ventriculitis, the authors retrospectively studied clinical, radiological and microbiological profiles of such patients. METHODS: We reviewed medical records and radiological findings of eleven patients with postcraniotomy ventriculitis managed between 1995 and 1999. External ventricular drainage(EVD) was performed for the purpose of retrieving cerebrospinal fluid(CSF) and instilling vancomycin. RESULTS: The mean duration for maintaining EVD elapsed 17.8 days and IVT instillation elapsed 11.9 days. The causative pathogens were revealed in eight patients ; methicillin-resistant Staphylococcus aureus(MRSA) in five, coagulase-negative Staphylococcus epidermidis(CNSE) in three. Vancomycin was instilled to patients with MRSA and CNSE. Empirical vancomycin was instilled to three patients with negative bacterial culture. Seizure was seen in one patient. Except one deceased patient, all showed clinical and laboratory improvement. Therapeutic drug monitoring(TDM) did not show any confidential relationship in three patients' status. CONCLUSION: Intraventricular instillation of vancomycin is an effective and safe method in treatment of the postcraniotomy ventriculitis. Complication is negligible and outcome is favorable in general. However, more refined TDM is required to attain steady CSF antibiotic concentration and prudent antibiotic selection is prerequisite to prevent formidable bacterial drug resistance.

Nucleoplasty as an Alternative Intradiscal Therapy in Patients with Lumbar Disc Herniation

OBJECTIVE: The nucleoplasty ablates, coagulates and decompresses the nucleus pulposus by way of high-density plasma field rather than by way of high thermal energy. The authors intended to describe the effects, indications and technical details of nucleoplasty. METHODS: From August 2001 to January 2002, the authors performed nucleoplasty for 40 consecutive patients (45 levels) and evaluated the short-term(mean 3 months) result after the procedure according to Macnab criteria. Exclusion criteria were same for the other percutaneous procedures, significant or ruptured, sequestered disc material, spinal stenosis, spinal instability, etc. Intraoperative discogram was prerequisite for determination of the precise causative level. Average operation time was 40 minutes, and patients discharged on the next day after the procedure. RESULTS: Male was outnumbered female by 21 to 19 and age was ranged from 20 to 67 years old(mean: 42.9). Procedures were performed at single level in 35 cases and at two levels in 5 cases. The L4-5 level was the most commonly involved. According to Macnab's outcome criteria, excellent and good outcome was achieved in 35 patients(87.5%), and fair and poor outcome was in 3(7.5%) and 2(5%) patients, respectively. CONCLUSION: Nucleoplasty by using coblation method in patients with lumbar disc herniation shows immediate relief of leg and back pain in 87.5% of the patients during the short span of follow-up. However, data collection with respect to the lengthening of population number and follow-up span, and refinement of strict inclusion/exclusion criteria are prerequisite in near future.