Biomedical subjects

S I Suk

Publications and source records attributed to S I Suk.

10 recordsLinked to original sources

PubMed2001

Thoracic pedicle screw fixation in spinal deformities: are they really safe?

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the safety of pedicle screw fixation in thoracic deformity correction. SUMMARY OF BACKGROUND DATA: Pedicle screw fixation enables enhanced correction of spinal deformities. However, the technique is still not widely applied for thoracic deformities for fear of neurologic complications. MATERIALS AND METHODS: A total of 462 patients subjected to thoracic pedicle screw fixation for spinal deformities were analyzed after a minimum follow-up of 2 years. Etiologic diagnoses were idiopathic scoliosis in 330, congenital kyphoscoliosis in 68, kyphosis in 50, and others in 14. They were reviewed using the medical records and preoperative, intraoperative, and postoperative roentgenograms. Computed tomography was performed when screw position was questionable. RESULTS: A total of 4604 thoracic pedicle screws were inserted (10.1 screws/patient). There were 67 screw malpositions (1.5%) in 48 patients (10.4%). The malpositions were inferior in 33, lateral in 18, superior in 12, and medial in 4. Screw-related neurologic complications occurred in four patients (0.8%); these comprised a transient paraparesis and three dural tears. Other complications comprised 11 intraoperative pedicle fractures, 35 screw loosenings, 9 postoperative infections, and 1 pneumothorax. There were no significant screw-related neurologic or visceral complications that adversely affected the long-term result. The deformity correction was 69.9% for idiopathic scoliosis and 60.7% for congenital scoliosis. The sagittal plane deformity correction was 47 degrees for kyphosis. CONCLUSIONS: Thoracic pedicle screw fixation is a reliable method of treating spinal deformities, with an excellent deformity correction and a high margin of safety.

Adolescent↗

PubMed2000

Indications of proximal thoracic curve fusion in thoracic adolescent idiopathic scoliosis: recognition and treatment of double thoracic curve pattern in adolescent idiopathic scoliosis treated with segmental instrumentation.

STUDY DESIGN: A retrospective study. OBJECTIVES: To determine the indications of fusing the proximal thoracic curve when treating idiopathic thoracic scoliosis with segmental instrumentation. SUMMARY OF BACKGROUND DATA: Failure to recognize a significant proximal thoracic curve often results in postoperative shoulder asymmetry due to relative overcorrection of the lower thoracic curve. With segmental instrumentation that enhances the correction of the instrumented curve, the double thoracic curve pattern that needs fusion of both the proximal and the distal thoracic curves should be redefined. METHODS: Forty patients with thoracic adolescent idiopathic scoliosis with a right lower thoracic curve of more than 40 degrees and a left proximal thoracic curve of more than 25 degrees treated by segmental pedicle screw instrumentation were analyzed after a minimum follow-up of 2 years. RESULTS: Of the 40 patients, 18 were treated by fusion of both the proximal and the distal curves, whereas 22 were treated by fusion of the distal curve only. The postoperative shoulder height difference (SHD, in millimeters) was 0.9 x preoperative SHD + 5.3 for the fusion of both curves and 0.6 x preoperative SHD + 12 for the distal curve fusion (linear regression), showing that proximal thoracic curve fusion improved the SHD when the left shoulder was level with or higher than the right. CONCLUSIONS: Idiopathic thoracic scoliosis with a proximal thoracic curve of more than 25 degrees and level or elevated left shoulder should be considered a double thoracic curve pattern and should be treated by fusing both the proximal and the distal curves when using segmental instrumentation.

Adolescent↗

PubMed1999

Restoration of thoracic kyphosis in the hypokyphotic spine: a comparison between multiple-hook and segmental pedicle screw fixation in adolescent idiopathic scoliosis.

This study verified the efficacy of segmental pedicle screw fixation in restoring thoracic kyphosis in persons with hypokyphotic scoliosis. Fifty-one patients were divided into three groups by the degree of preoperative thoracic hypokyphosis and fixation method used: the hypokyphosis-hook (HH), hypokyphosis-screw (HS), and normal kyphosis-screw (NS) group. They were compared after a minimum follow-up period of 2 years. Preoperative thoracic kyphosis of 4.1 degrees +/- 8.6 degrees, 8.1 degrees +/- 5.6 degrees and 27.3 degrees +/- 9.8 degrees in the HH, HS, and NS groups were restored to 14.5 degrees +/- 10.2 degrees, 27.3 degrees +/- 11.3 degrees, and 28.3 degrees +/- 13.7 degrees, respectively. The difference between the HH and HS groups was significant (p = 0.000). The HS and the NS groups did not differ (p = 0.16). This indicates that segmental pedicle screw fixation was more effective than multiple hooks in restoring kyphosis in patients with hypokyphotic scoliosis and created kyphosis similar to that in patients without preoperative hypokyphosis.

Adolescent↗

PubMed1997

Adding posterior lumbar interbody fusion to pedicle screw fixation and posterolateral fusion after decompression in spondylolytic spondylolisthesis.

STUDY DESIGN: This is a retrospective study analyzing 76 patients treated by decompression, pedicle screw instrumentation, and fusion for spondylolytic spondyiolisthesis with symptomatic spinal stenosis. OBJECTIVES: To verify the advantages of adding posterior lumbar interbody fusion to the usual posterolateral fusion with pedicle screw instrumentation. SUMMARY OF BACKGROUND DATA: Stabilization after decompression of spondylolytic spondylolisthesis is difficult because of a lack of fusional bone bases, gap between the transverse process bases, and incompetent anterior disc support. Posterior lumbar interbody fusion offers anterior support, reduction, and a broad fusion base. METHODS: Forty patients were treated with posterolateral fusion, and 36 were treated with additional posterior lumbar interbody fusion. They were compared for union, reduction of the deformity, and clinical results. RESULTS: The patients were followed up for more than 2 years. Nonunion was observed in three patients who underwent posterolateral fusion (7.5%), and no cases of nonunion was found in patients who underwent posterior lumbar interbody fusion. Reduction of slippage was 28.3% in those who underwent posterolateral fusion and 41.6% in those who had posterior lumbar interbody fusion (P = 0.05). In the posterolateral fusion group, eight patients (20%) had recurrence of deformity, with loss of reduction more than 50%. Hardware failures occurred in two patients who had posterolateral fusion. There was no major neurologic complications in both groups. Both groups had satisfactory results in more than 90% of patients, with marked improvement of claudication. However, subjective improvement of back pain by Kirkaldy-Willis criteria revealed differences in the excellent results. An excellent result was reported by 45% in the posterolateral fusion group and by 75% in posterior lumbar interbody fusion group. CONCLUSIONS: The addition of posterior lumbar interbody fusion to posterolateral fusion after a complete decompression and pedicle screw fixation is a recommended procedure for the treatment of spondylolytic spondylolishesis with spinal stenosis.

Adult↗

PubMed1995

Segmental pedicle screw fixation in the treatment of thoracic idiopathic scoliosis.

STUDY DESIGN: This retrospective clinical study compared the results of correction of idiopathic thoracic scoliosis using Cotrel-Dubousset segmental pedicle screw fixation with those of hooks and screws inserted in a hook pattern. OBJECTIVES: The study's objective was to evaluate the efficacy and safety of segmental pedicle screw fixation in the management of idiopathic thoracic scoliosis. SUMMARY OF BACKGROUND DATA: Seventy-eight idiopathic thoracic scoliosis patients were treated with Cotrel-Dubousset instrumentation from 1987 to 1991. Thirty-one were treated with hooks; 23 were treated with pedicle screws inserted in a hook pattern; and 24 were treated with segmental pedicle screws. METHODS: After a minimum follow-up of 2 years (range, 25-52 months), the results of frontal, sagittal, and rotational correction of each group were compared and statistically analyzed using analysis of variance. RESULTS: Major curve correction was 55% with hooks, 66% with hook pattern screws, and 72% with segmental screws, with loss of correction of 6%, 2%, and 1%, respectively. Compensatory curve correction was 57% with hooks, 67% with hook pattern screws, and 70% with segmental pedicle screws. In patients with hypokyphosis, all showed significant improvement with best restoration in segmental screws. Rotational correction of the apical vertebra measured by the Perdriolle method was 19% with hooks, 26% with hook pattern screws, and 59% with segmental screws. Thirteen screws (3%) were malpositioned, but they did not cause neurologic impairment or adversely affect the results of treatment. CONCLUSIONS: Segmental pedicle screw fixation is a safe and effective method for correcting the triplanar deformity of the idiopathic thoracic scoliosis.

Adult↗

PubMed1994

Comparison of Zielke ventral derotation system and Cotrel-Dubousset instrumentation in the treatment of idiopathic lumbar and thoracolumbar scoliosis.

There has been much controversy, in the surgical treatment of idiopathic thoracolumbar and lumbar scoliosis, about whether anterior or posterior instrumentation produced a better result. This study compared the Zielke ventral derotation system (VDS) and Cotrel-Dubousset instrumentation (CDI) in the correction of frontal, sagittal, and rotational deformity, and defined the advantage and disadvantage of each instrument in idiopathic thoracolumbar and lumbar scoliosis. The ventral derotation system was used in 20 patients (VDS group) and Cotrel-Dubousset instrumentation was used in 20 patients (CDI group). The average age of VDS group patients at the time of surgery was 16.7 years, and that of CDI group patients was 18.5 years. The average length of follow up was 48 and 25 months, respectively. In frontal curve correction, the VDS group showed a 77% correction, and the CDI group a 63% correction (P > 0.05). In rotational deformity correction, the VDS group showed a 42% correction, and the CDI group a 16% correction (P < 0.05). There were six decompensations in the VDS group, and three in the CDI group. Two decompensations of the VDS group were corrected with posterior CDI. There was one pseudarthrosis in the VDS group, with no significant symptoms. There were two instrumentation problems in each group, with no adverse effects on curve correction and maintenance. In conclusion, the ventral derotation system showed more powerful frontal and rotational correction, and can be effective even in more rigid or larger curves. Cotrel-Dubousset instrumentation, however, maintained physiologic sagittal alignment, was performed using a less invasive posterior approach, and had broader indication because it could be extended upward or downward to the compensatory curves.

Adolescent↗

PubMed1994

Comparison of Cotrel-Dubousset pedicle screws and hooks in the treatment of idiopathic scoliosis.

Eighty-two patients with idiopathic scoliosis were treated by Cotrel-Dubousset instrumentation between 1987 and 1991. Twenty were treated with hooks only, 47 with screws and hooks, and 15 with screws only. The methods were compared and the findings showed that screw fixation can be used in the thoracic spine without neurological complications. The screws provided immediate stability with rigid fixation, together with better correction of frontal, sagittal and rotational deformity. There is less loss of correction, a shorter fusion and less risk of neurological complications because of the placement outside the spinal canal and the rigid fixation in derotation. The technique was simpler and the operating time shorter than with the other methods.

Adolescent↗

PubMed1993

Multicore myopathy--a case report.

Multicore myopathy is a rare congenital myopathy. The multicores consist of numerous small areas of decreased oxidative enzyme activity. The long axis of the lesion is perpendicular or parallel to the long axis of the muscle fiber. These cores are usually smaller than central cores. For this reason they are also called minicores. Although the multicores represent a nonspecific change in that they can be observed in malignant hyperthermia, muscular dystrophy, inflammatory myopathy, etc. Muscular weakness dating from early infancy is combined large proportion of the muscle fibers. In about half of the reported cases the muscular weakness has not been progressive, while in the others a slow progression has occurred. This 9-year-old boy presented with congenital nonprogressive myopathy associated with thoracic scoliosis and bilateral equinovarus deformity. The serum creatine phosphokinase and lactic dehydrogenase levels were normal. Electromyography showed "myopathic" features. The biopsy revealed a marked size variation in myofibers, ranging from 10 microns to 100 microns. A few small angular fibers and slight endomyseal fibrosis were also noted. There was type I fiber predominance. NADH-TR reaction disclosed more well-defined cores with loss of intermyofibrillary mitochondrial activity. These cores were usually located with loss of intermyofibrillary mitochondrial activity. These cores were usually located in the peripheral portions of the myofibers and the core size measured 10-30 microns in diameter. Electron microscopic examination revealed circumscribed areas of disintegrated Z band material and disorganized sarcomeric units near the sarcolemma. A decrease in the number of mitochondria and glycogen particles was noted.

Biopsy↗

PubMed1991

A study on platelet function in idiopathic scoliosis.

Because platelets and muscle cells share the same contractile proteins--actin and myosin--platelets may serve as a model for muscle research. To study the functional abnormalities and ultrastructural changes of platelets and to determine whether or not abnormalities in muscle contractile proteins and collagen play an important role in the pathogenesis of idiopathic scoliosis, the bleeding time, the platelet aggregation test, and the titers of platelet plasminogen activator inhibitors were measured and the electron microscopic findings were examined in 52 idiopathic scoliosis patients aged 7 to 28 years and in 49 normal individuals aged 8 to 38 years as a control group. We found no statistically significant difference between the two groups in the bleeding time, the platelet aggregation test, and the titers of platelet plasminogen activator inhibitors. In the electron microscopic findings, no specific abnormalities were found in platelets of idiopathic scoliosis patients. We concluded that idiopathic scoliotic patients have normal morphology and function of platelets, and there is no important role of contractile proteins in the pathogenesis of idiopathic scoliosis. In addition, since the bleeding time was in the normal range, no evidence of subendothelial collagen dysfunction was found in the idiopathic scoliosis patients.

Adolescent↗

PubMed1989

Scoliosis induced by anterior and posterior rhizotomy.

This paper presents the result and statistical analysis of an experiment in which selective anterior or posterior rhizotomy was carried out under microscopic surgery. The animals used for the experiment were 48 young rabbits, and they were divided into four groups. Group 1, which was used as control, was subjected to lower dorsal bilateral laminectomies with dural incision; Group II to laminectomies with three right posterior rhizotomies; Group III to laminectomies with three right anterior rhizotomies, and Group IV to laminectomies with three right anterior and posterior rhizotomies. Scoliosis was induced in Groups II, III, and IV. There was no significant statistical difference in the degree of curvatures among these three groups. The convexity of the curvature faced to the side of the divided roots. In Groups III and IV, scoliotic curvatures were obvious within 2 weeks, but there were no considerable changes thereafter. In Group II, the curves progressed slowly up to the 12th week. They were statistically significant at the fourth week and increased continuously thereafter. The histologic findings in Groups III and IV showed denervation atrophy of the paravertebral muscles at the apex of the curvature, but there was little or no muscle atrophy in Groups I and II. The experimental results indicate that scoliosis may be induced not only by anterior root paralysis but also by selective posterior root paralysis.

Animals↗