Park Ck

Degenerative changes of discs and facet joints in lumbar total disc replacement using ProDisc II: minimum two-year follow-up.

Study Design. A retrospective clinical and radiologic data analysis. Objective. To determine the radiologic changes in the discs at the adjacent levels and facets at the index and adjacent levels after total disc replacement (TDR) using ProDisc II in a minimum 2-year follow-up. Summary of the Background Data. The main purposes of TDR are to preserve the physiologic segmental motion at index level, and to prevent accelerated degeneration at the index and adjacent segments. However, there are few reports dealing with the effects of TDR on the degenerative changes in a long-term follow-up. Methods. After TDR using ProDisc II, the degree of disc and facets degeneration at the index and adjacent levels was assessed by observing lumbar magnetic resonance imaging (MRI) and computed tomography (CT) images before surgery and at minimum 26 months after operations. The degenerative changes of the discs and facets were determined in relation to the clinical outcome, various perioperative factors, and prosthesis factors. Results. Thirty-two patients with 41 TDR included in this investigation. The progression of facets degeneration (PFA) was observed in 12 of 41 TDR levels. Among 47 adjacent segments, the progression of disc degeneration and PFA were observed in 2 levels (4.3%), and 3 levels (6.4%), respectively. All cases of PFA occurred only in those with preoperative degeneration of grade 1. PFA at the index segments was positively related with female in gender (P = 0.008), the malposition of prosthesis on frontal plane (P = 0.025), and 2-level TDR in the number of TDR level (P = 0.008). Conclusion. After TDR using ProDisc II, the degenerative changes in the discs and facets at the adjacent segments appeared to be minimal. However, in 29.3% of the TDR segments, the facet joints presented PFA, which was more common in female, malposition of prosthesis on frontal plane, and 2-level TDR in a minimum 2-year follow-up.

Clinical Outcome of Lumbar Total Disc Replacement Using ProDisc-L in Degenerative Disc Disease : Minimum 5-Year Follow-up Results at a Single Institute

Study Design. A retrospective clinical data analysis. Objective. To determine the therapeutic effectiveness of lumbar total disc replacement (TDR) using ProDisc-L (Synthes Spine, West Chester, PA) in the patients with degenerative disc diseases (DDD) with a minimum follow-up of 5 years. Summary of Background Data. Early successful clinical results of lumbar TDR have been reported. However, few reports have published its therapeutic effectiveness in the long term. Methods. The patients were examined preoperatively and at 3 months, 1 year, 2 years, and more than 5 years postoperatively, and assessed using visual analog scale (VAS), Oswestry disability index (ODI), physical health component summary (PCS) of the 36-Item Short Form Health Survey questionnaire, and sporting activity scale scores. At last follow-up visits, two additional questions were asked: satisfaction with surgery and willingness to undergo the same treatment. Finally, clinical success was assessed using the Food and Drug Administration definition. Results. Thirty-five patients were included in the study. The mean follow-up period was 72 months (6 years). Postoperatively, all outcome measure scores (VAS, mean ODI, PCS, and sports activity scores) immediately improved and these improvements were maintained at last follow-up visits with statistical significance. However, outcome score improvements were observed to be slightly, though significantly, lower at last follow-up visits than at 1 or 2 years postoperatively. Eighty-eight percent of patients were “satisfied” or “somewhat satisfied” with treatment and 60% were prepared to undergo the same treatment again. Twenty-five patients (71.4%) achieved clinical success. Conclusion. This study reveals that lumbar TDR using ProDisc-L is a safe and effective treatment for chronic back pain caused by lumbar DDD as assessed at more than 5 years postoperatively. Nevertheless, outcome scores were slightly, though significantly lower at last follow-up visits than at 1 and 2 years postoperatively. A longer-term follow-up study is warranted.

Radiological changes of the operated and adjacent segments following cervical arthroplasty after a minimum 24-month follow-up: comparison between the Bryan and Prodisc-C devices

OBJECT The purposes of this retrospective study were to determine the radiological changes at the index and adjacent levels after cervical arthroplasty using the Bryan disc and Prodisc-C disc after a minimum 24 months follow-up, and to demonstrate the possible clinical factors related to these changes. METHODS Following single-level cervical arthroplasty using either the Bryan disc or Prodisc-C, the degree of facet degeneration and other radiological changes at the index and adjacent levels were assessed by observing radiographs and CT scans at a minimum 24 months after the operations. These findings were determined in relation to the clinical outcome, various perioperative factors, and prosthesis factors. Thirty-six patients were included in this investigation (19 in the Bryan disc group and 17 in the Prodisc-C group). RESULTS At the index level, progression of facet arthrosis (PFA) was observed in 7 of 36 levels (1 level with the Bryan disc, 6 with the Prodisc-C). At adjacent levels, PFA was minimally observed. Heterotopic ossification (HO) was observed at 19 levels (11 with the Bryan disc, 8 with Prodisc-C). Progression of facet arthrosis at the index segments was positively related to malposition of the prosthesis on the frontal plane, and decreased postoperative functional spinal unit range of motion at the index level. Occurrence of HO was correlated with the preoperative calcification of the posterior longitudinal ligament at the operated level, regardless of prosthesis type. Clinical outcome and the occurrence of PFA or HO did not show any significant relationship. CONCLUSIONS This study demonstrates that the incidence of PFA at the index level is 19.4% after a minimum 24-month follow-up, and occurs more frequently in the Prodisc-C group. Progression of facet arthrosis is related to less functional spinal unit range of motion and anterior placement of the prosthesis. The occurrence rate of HO is high, regardless of the type of prosthesis, and it is significantly correlated with preoperative calcification of the posterior longitudinal ligament at the operated level.

Prospective Comparison Study Between the Fluoroscopy-guided and Navigation Coupled With O-arm-guided Pedicle Screw Placement in the Thoracic and Lumbosacral Spines.

Study Design: This is a prospective randomized comparison study between the fluoroscopy-guided and navigation coupled with O-arm–guided pedicle screw placement in the thoracic and lumbosacral spines. Objective: The objective of the study was to evaluate the accuracy and clinical benefits of a navigation coupled with O-arm–guided method in the thoracic and lumbar spines by comparing with a C-arm fluoroscopy-guided method. Methods: Under fluoroscopy guidance, 138 pedicle screws were inserted from T9 to S1 in 20 patients, and 124 pedicle screws were inserted from T9 to S1 in 20 patients using the navigation. The position of the screws within the pedicle was assessed from grade 0 (no violation cortex) to grade 3 (>4 mm violation), and the location of the violated cortex was determined. Preparation time of each equipment setting, time for screwing, and the number of x-ray shots were evaluated. Results: The number of screws observed as grade 0 was 121 (87.7%) in the fluoroscopy-guided group and 114 (91.9%) in the navigation-guided group. The lateral cortex was most commonly involved in the fluoroscopy-guided group (6 cases, 35.3%), and the medial cortex was most common in the navigation-guided group (4 cases, 40%). The mean time required for preparation for screw placement was 3.7 minutes in the fluoroscopy-guided group and 14.2 minutes in the navigation-guided group. Average screwing time was 3.6 minutes in the fluoroscopy-guided group and 4.3 minutes in the navigation-guided group. The mean number of x-ray shots for each screw placement in the fluoroscopy-guided group was 6.5. Postoperatively, 2 patients with misplacement of a screw under fluoroscopy guidance presented ipsilateral leg paresthesia, possibly related to the screw position. Conclusions: The present prospective study reveals that the pedicle screw placement guided by the navigation coupled with O-arm system was more accurate and safer than that under fluoroscopy guidance.

Factors influencing segmental range of motion after lumbar total disc replacement using the ProDisc II prosthesis

OBJECT The purpose of this prospective controlled study was to evaluate possible factors that could affect postoperative segmental range of motion (ROM) after lumbar total disc replacement (TDR) using the ProDisc II prosthesis. METHODS Thirty-two consecutive patients with intractable discogenic pain underwent lumbar TDR using the ProDisc II prosthesis, 30 of whom were followed up for at least 24 months. Segmental ROM was assessed preoperatively and every 6 months postoperatively using dynamic x-ray films. Segmental ROM at the reference level was assessed in relation to patient age, sex, body mass index (BMI), levels with implants, preoperative ROM, prosthesis size, and prosthesis position. RESULTS At the last follow-up visit, mean ROM of the disc prostheses was significantly increased from 4.23 +/- 3.12 degrees to 6.81 +/- 3.76 degrees at L3-4, and from 3.66 +/- 2.47 degrees to 6.09 +/- 2.11 degrees at L4-5. Mean ROM at L5-S1, however, was decreased from 3.12 +/- 1.56 degrees to 2.86 +/- 1.26 degrees (p > 0.05). This difference in the changes in postoperative ROM between L5-S1 and the other operated levels was the only statistically significant factor (p = 0.025) among the variables related to the postoperative ROM that the authors assessed, but other factors such as patient age, sex, BMI, disc height, and the size and position of the prosthesis were not related to segmental ROM. CONCLUSIONS The data demonstrate that after TDR using the ProDisc II prosthesis, ROM of the prosthesis at L5-S1 is significantly lower compared with ROM at the other levels. In preserving ROM, the advantage of lumbar TDR using the ProDisc II might be minimal at L5-S1. Among the variables related to postoperative ROM, the level at which the ProDisc II prosthesis was implanted was the only one found to be statistically significant.

Single balloon kyphoplasty using far-lateral extrapedicular approach: technical note and preliminary results.

Objectives The authors have performed a single-balloon kyphoplasty using far-lateral extrapedicular approach in the treatment of osteoporotic vertebral compression fractures. The authors introduce its surgical technique and early clinical results. Methods Clinical outcomes were determined by comparison of preoperative and postoperative visual analog scale score. Radiographic assessment included vertebral height restoration rate (%) and correction of kyphosis. Results Thirty-one consecutive patients with 37 vertebrae were treated during a 5-month period and followed up for more than 6 months. Twenty-nine of 31 patients (95%) improved the visual analog scale pain score postoperatively (P<0.001). The average anterior body height was 60.85±14.27% of estimated height before procedure and 81.86±12.78% of estimated height after procedure (P<0.007). The average middle body height was 63.14±14.42% of estimated height before procedure and 80.94±18.44% of estimated height after procedure (P<0.001). The mean height restoration ratio was 31.72±20.98%. The kyphotic deformity was corrected from 16.06±5.24 degree to 8.84±3.89 degree (P<0.001). There was no surgery and device-related complications. Conclusions Single-balloon kyphoplasty using far-lateral extrapedicular approach is less invasive procedure that produces comparable therapeutic effects with the conventional 2-balloon technique.

Temozolomide chemotherapy in patients with recurrent malignant gliomas.

Numerous studies have demonstrated the clinical activity of temozolomide, a second-generation alkylating agent, against malignant brain tumors, however, its activity has not been reported in an Asian population. This study analyzed the efficacy and toxicity of temozolomide in 25 adult patients with recurrent or progressive malignant gliomas after surgery and standard radiation therapy with or without chemotherapy, enrolled in our institution since July 2000. Sixteen patients had glioblastoma multiforme (GBM), six with anaplastic astrocytoma, and three with anaplastic oligodendroglioma. Of the 25 patients, 3 (12%) achieved a complete response (CR), 8 (32%) achieved a partial response (PR), 6 (24%) had stable disease (SD), and 8 (32%) had progressive disease (PD). Two patients achieved a CR, 4 patients achieved a PR, 3 patients had SD and 7 patients had PD in GBM, and 1 patient achieved a CR, 4 patients achieved a PR, 3 patients had SD, 1 patient had PD in the non-GBM patients. Median progression free survival was 8 weeks in GBM and 22 weeks in the non-GBM patients. The median overall survival of each group was 17 weeks and 28 weeks. Temozolomide demonstrated moderate activity in recurrent and progressive malignant gliomas without serious toxicity.

Quantitative anatomy of the endplate of the middle and lower cervical vertebrae in Koreans.

Study Design. Assessment of the size and shape of cervical vertebral endplates in Koreans. Objective. To obtain data regarding cervical vertebrae and propose an appropriate size for artificial discs in Koreans. Summary of Background Data. The use of various types of cervical artificial discs has increased in recent years; hence, it is important to develop endplate implants of appropriate size. In this study, we determined the quantitative anatomy of cervical endplates in Koreans and proposed a new angular parameter. Methods. This study details the quantitative surface anatomy of the middle and lower cervical vertebral endplates based on the study of 272 cervical vertebrae in Korean cadavers. Computed tomographic images were obtained from 57 Korean cadavers (28 males and 29 females). The mean age and height were 51.14 years (range, 21–60 years) and 161 cm (range, 146–175 cm), respectively. The images were reconstructed, and linear parameters (EPWu, upper endplate width; EPDu, upper endplate depth; EPWl, lower endplate width; and EPDl, lower endplate depth) and an angular parameter (AUA, anterior wall to uncovertebral joint angle) were measured. Results. The width and depth of both the upper and lower endplates increased from C3 through C7. The EPDu, EPWl, and EPDl values of Koreans were similar to those reported in whites, while the EPWu value in this study were smaller than those reported in whites. The AUA for C4 differed significantly between the sexes. The linear parameter values obtained using Korean cadavers were compared with those obtained using white and Singaporean subjects. The EPWu values of Koreans were smaller than those reported in whites, while the values for all the parameters were considerably larger than those reported in Singaporeans. The AUA indicated the existence of various relationships between the endplate and the uncovertebral joint. Conclusions. This data can be used to develop cervical devices for Koreans. The AUA should be studied in other populations.

Cranioplasty effect on the cerebral hemodynamics and cardiac function.

BACKGROUND Cranioplasty is usually performed for aesthetic, protective and patient comfort reasons. The objective of this study is to examine the effects of cranioplasty on the cerebral hemodynamics and cardiovascular system. METHODS Twenty-seven patients who had undergone cranioplasty after extensive skull bone removal to prevent uncontrollable intracranial hypertension were included in this study. Arterial blood flow velocities in the middle cerebral artery (MCA) and internal carotid artery (ICA) were assessed by transcranial doppler (TCD). The cardiac functions were evaluated using the echocardiogram. And cerebral blood flow were measured by perfusion CT. FINDINGS The blood flow velocity at the MCA ipsilateral to the cranioplasty was decreased from 50.5 +/- 15.4 cm/s preoperative to 38.1 +/- 13.9 cm/s following cranioplasty (p < 0.001) and from 33.1 +/- 8.3 cm/s to 26.4 +/- 6.6 cm/s at the ICA (p < 0.001). The stroke volume was increased from 64.7 +/- 18.3 ml/beat, to 73.3 +/- 20.4 ml/beat (p < 0.001), while the cardiac output and mean arterial blood pressure were unchanged. The cerebral blood flow was increased from 39.1 +/- 7.2 ml/100g/min to 44.7 +/- 8.9 ml/100g/min on the cranioplasty side (P = 0.05). CONCLUSIONS Cranioplasty can get rid of the atmospheric pressure on the brain and increase the cerebral blood flow as well as improve the cardiovascular functions. A skull defect should be corrected, because cranioplasty has not only aesthetic or protective effects but also improves the cardiovascular functions.

Sacral Intraspinal Bronchogenic Cyst: A Case Report

Intraspinal bronchogenic cysts are rare congenital cystic lesions. In all the reported cases, the cysts have been located in the cervical, upper thoracic or thoracolumbar segments. We report the case of an intraspinal bronchogenic cyst in the sacral location. We present the case of a 5-month-old female with a skin dimple in the midline over the sacral vertebra. Magnetic resonance image of the lumbar and sacral vertebra revealed a dermal sinus tract and an epidural cystic mass at the S2 level. The patient underwent the removal of the dermal sinus tract and the cyst. The cystic mass was shown to be connected to the subarachnoid space through a slender pedicle from the dura. The cyst was diagnosed to be a bronchogenic cyst based on the results of the histopathological examination. We conclude that intraspinal bronchogenic cysts may appear in the sacral location.