Pedicle Screw Fixation in Pediatric Spinal Deformities: Results for patients under 10 years old / 대한정형외과학회잡지

PURPOSE: We wanted to determine the efficacy of performing pedicle screw fixation to treat pediatric spinal deformities and we also wanted to evaluate its long-term effects on the growing spine. MATERIALS AND METHODS: Thirty-eight consecutive spinal deformity patients (25 congenital, 9 idiopathic and 4 other etiologies) under 10 years old at the time of the surgery who underwent pedicle screw instrumentation were reviewed after a minimum follow up of 2 years (range: 2 to 7 years). To evaluate the effect of the pedicle screws on the growing spine, a thin slice CT scan was performed in 27 patients (72%) at the last follow up. The patients were treated by posterior fusion with segmental pedicle screw fixation being performed in 21 patients, vertebral column resection combined with segmental pedicle screw fixation was done in 16 patients and combined anterior and posterior correction was done in 1 patient. RESULTS: The frontal correction was 67.2% in the posterior fusion group, 71.5% in the posterior resection group and 64.7% in the patients who underwent combined anterior and posterior correction. A mean correction of 20degrees was obtained in the sagittal plane. A total of 341 pedicle screws were inserted (an average of 8.9 screws per patient). The complications were comprised of 7 screw malpositions (2.1%), 1 loss of fixation (screw pull-out), 1 recurrence of deformity and one superficial infection. There were no significant neurological or vascular complications. Any Symptoms or radiological evidence suggestive of spinal stenosis were not detected in any of the patients. CONCLUSION: Pedicle screw fixation may be used with the same efficacy for pediatric spinal deformities, and even for the patients under 10 years old, without causing any hazard of iatrogenic spinal stenosis.

Epidemiologic study of lumbar scoliosis with plain abdominal X-ray / 대한척추외과학회지

STUDY DESIGN: A retrospective cross-sectional study OBJECTIVES: To analyze the prevalence and characteristics of lumbar scoliosis using plain abdominal X-rays, according to age. LITERATURE REVIEW SUMMARY: The single lumbar curves of adolescents have shown 10 ~20% idiopathic scoliosis, but the reported prevalence of adult lumbar scoliosis ranges from 2.5 to 7.5%. In Korea, there is no useful basic data concerning lumbar scoliosis. MATERIALS AND METHODS: A total of 2877 plain abdominal radiographies (supine and erect), taken at our hospital, between August 2001 and June 2002, were retrospectively investigated. The ages of the patients ranged from 11 to 80 years, and the patients were grouped according to age. The prevalence, Cobb angle, ratio of males and females, ratio of right and left curves, location of end and apex vertebra, the number of involved vertebra in primary curve, amount of rotation and osteophytes were all examined. RESULTS: The overall prevalence of lumbar scoliosis was 4.3% (N=124), but rapidly increased after the sixth decade. The average Cobb angle was 16.2 degree. A positive correlation was found between the Cobb angle and age (r=0.275, P<0.05). The ratios of males to females and of the right to left curves were both about 1:2. The most common sites of upper end vertebra were T12 and L1, that of the lower end vertebra L4 and those of the apex L2 (N=48) and L3 (N=40). Most (N=111) had grade 1 rotation. With regard to the magnitude of the curves, no other factors were statistically significant. CONCLUSIONS: De novo scoliosis can be considered to develop rapidly after the sixth decade. The Cobb angle had a positive correlation with age (r=0.275, p<0.05). These data are thought could be useful and valuable for future study of lumbar scoliosis.

Epidemiologic study of lumbar scoliosis with plain abdominal X-ray / 대한척추외과학회지

STUDY DESIGN: A retrospective cross-sectional study OBJECTIVES: To analyze the prevalence and characteristics of lumbar scoliosis using plain abdominal X-rays, according to age. LITERATURE REVIEW SUMMARY: The single lumbar curves of adolescents have shown 10 ~20% idiopathic scoliosis, but the reported prevalence of adult lumbar scoliosis ranges from 2.5 to 7.5%. In Korea, there is no useful basic data concerning lumbar scoliosis. MATERIALS AND METHODS: A total of 2877 plain abdominal radiographies (supine and erect), taken at our hospital, between August 2001 and June 2002, were retrospectively investigated. The ages of the patients ranged from 11 to 80 years, and the patients were grouped according to age. The prevalence, Cobb angle, ratio of males and females, ratio of right and left curves, location of end and apex vertebra, the number of involved vertebra in primary curve, amount of rotation and osteophytes were all examined. RESULTS: The overall prevalence of lumbar scoliosis was 4.3% (N=124), but rapidly increased after the sixth decade. The average Cobb angle was 16.2 degree. A positive correlation was found between the Cobb angle and age (r=0.275, P<0.05). The ratios of males to females and of the right to left curves were both about 1:2. The most common sites of upper end vertebra were T12 and L1, that of the lower end vertebra L4 and those of the apex L2 (N=48) and L3 (N=40). Most (N=111) had grade 1 rotation. With regard to the magnitude of the curves, no other factors were statistically significant. CONCLUSIONS: De novo scoliosis can be considered to develop rapidly after the sixth decade. The Cobb angle had a positive correlation with age (r=0.275, p<0.05). These data are thought could be useful and valuable for future study of lumbar scoliosis.

Posterior Vertebral Column Resection (PVCR) in Fixed Lumbosacpal Deformity / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To report the results and techniques of posterior vertebral column resections for fixed lumbosacral deformity. SUMMARY OF LITERATURE REVIEW: Fixed lumbosacral deformity results in gross imbalance and progressive compensatory thora-columbar deformity due to the absence of a mobile spine caudally. MATERIAL AND METHODS: Twenty-five consecutive fixed lumbosacral deformity patients subjected to PVCR were reviewed after a minimum follow-up of 2 years. The offending vertebra was below the L4 in all cases. The etiological diagnoses were congenital scoliosis, congenital kyphoscoliosis, post-traumatic kyphosis and post-infectious kyphosis in 6, 3, 2 and 14 patients, respectively. The average age at the time of operation was 38 years, with a male:female ratio of 7:18. The indication for PVCR was fixed lumbosacral deformities that could not be brought to a reasonable balance on traction or forced side bending. RESULTS: On average 2.1, ranging from 1 to 5, vertebrae were removed, with 52 removed in all. The average fusion extent was 4.5 vertebrae, ranging from 2 to 8. An anterior column reconstruction was carried out with an autogenous bone graft in all patients, with the additional insertion of titanium mesh in 12. The distal anchor went down to the L5, S1 and S2 in 4, 12 and 9 patients, respectively. A preoperative scoliosis of 3812 was corrected to 158 (60% correction), and a preoperative kyphosis of 3525 was corrected to -511 (40% correction). A preoperative coronal imbalance of 2.0cm was improved to 0.9cm, and a preoperative sagittal imbalance of 9.3 cm was improved to 4.6 cm. The mean operation time and blood loss were 280 minutes and 2810ml, respectively. Following complications were encountered in 5 patients: 2 transient neurologies, 2 compression fractures at proximal adjacent vertebra and 1 pseudoarthrosis. CONCLUSIONS: A posterior vertebral column resection is an effective procedure for the management of a fixed lumbosacral deformity. It provides satisfactory correction and improved functional outcomes. However, it is a technically demanding and exhausting procedure, with possible risks for complications

Segmental Pedicle Screw Fixation in Thoracolumbar or Lumbar Idiopathic Scoliosis / 대한정형외과학회잡지

PURPOSE: To analyze surgical outcomes of thoracolumbar and lumbar scoliosis treated with segmental pedicle screw fixation, and to determine the exact distal fusion level. MATERIALS AND METHODS: Seven idiopathic thoracolumbar and lumbar scoliosis patients (6 thoracolumar and 1 lumbar scoliosis, 7 females with mean age of 15.9 years) subjected to segmental pedicle screw fixation with a minimum follow-up of 2 years were retrospectively analyzed for deformity correction, stable vertebra, lower instrumeted vertebral tilt (LIVT) and coronal balance using pre and post-operative standing radiographs. The bending stable vertebra and the rotational correction of L3 were measured in preoperative bending radiographs. The L3 rotation in the bending radiographs was less than Nash-Moe grade II in all patients. The bending stable vertebra was L3 in 4 patients and L4 in 3. An unsatisfactory result was defined as an LIVT of more than 10degrees or a coronal imbalance of more than 10 mm. RESULTS: Distal fusion went down to L3 in 6 patients and L4 in one patient whose bending stable vertebra had been L4 preoperatively. The preoperative average major curve of 52degrees was corrected to 10degrees (81% correction). The preoperative average thoracic curve of 27degrees and the average lumbosacral curve of 26degrees were corrected to 14degrees and 5degrees, respectively. Two patients with distal fusion to L3 showed unsatisfactory results; LIVT was more than 10degrees in both patients and coronal imbalance more than 10 mm in one. Both the patients had bending stable vertebra of L4 preoperatively. CONCLUSION: In the correction of thoracolumbar and lumbar scoliosis with segmental pedicle screw fixation, the curve could be fused to L3 when the L3 rotation in the bending radiograph was less than Nash-Moe grade II and the bending stable vertebra was L3.

Posterior Vertebral Column Resection for Severe Spinal Deformities / 대한정형외과학회잡지

PURPOSE: To report a technique of vertebral column resection using a single posterior approach and its results in the treatment of severe spinal deformities. MATERIALS AND METHODS: Seventy spinal deformity patients treated by posterior vertebral column resection (PVCR) were retrospectively reviewed with minimum follow up of 2 years (2-3.3 years). There were 34 males and 36 females with a mean age of 27.4 years. Etiologic diagnoses were; adult scoliosis in 7, congenital kyphoscoliosis in 38, and post-infectious kyphosis in 25. The surgery consisted of temporary stabilization of the vertebral column with segmental pedicle screw fixation, resection of the vertebral column at the apex of the deformity via the posterior route followed by gradual deformity correction and fusion. Radiological and clinical data were reviewed for deformity correction and clinical results. RESULTS: The total number of resected vertebrae were 143: 76 thoracic and 67 lumbar. Mean operation time was 4 hours 31 minutes with an average blood loss of 2, 333 mL. The deformity correction was 62.9% in the coronal plane and 45.2 degrees in the sagittal plane. Complications were encountered in 24 patients: 2 complete cord injuries in severe adult scoliosis and a single thoracic kyphosis patient who had significant preoperative cord compromise, 6 hematomas, 4 root injuries (all incomplete), 5 fixation failures, 2 infections and 5 hemopneumothoraxes. CONCLUSION: PVCR is an effective alternative for severe fixed spinal deformities. However, extreme caution must be taken in patients with preoperative cord compromise who have a high risk of neurological complications.

Prevention of the Crankshaft Phenomenon with Posterior Pedicle Screw Fixation in Scoliosis of the Skeletally-Immature Spine / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the results of posterior segmental pedicle screw fixation in skeletally immature patients with scoliosis. SUMMARY OF LITERATURE REVIEW: Scoliosis correction, in the immature spine, frequently necessitates additional anterior surgery to prevent the crankshaft phenomenon. With the advent of posterior segmental pedicle screw fixation, it is unclear whether an additional anterior procedure will be required. MATERIAL AND METHODS: Seventeen scoliosis patients (10 idiopathic, 4 congenital and 3 others; 3 males and 14 females) were treated with segmental pedicle screw fixation only. Their results were reviewed for a deformity progression of more than 10 degrees, a rib vertebra angle difference (RVAD) progression of more than 10 degrees, and evidence of adding-on. All the patients had a 0 Risser index at the time of the operation. The mean age and follow-up times were 10.4, ranging from 7.2 to 11.8 years old, and 4.0, ranging from 3.0 to 5.4 years, respectively. RESULTS: The mean preoperative thoracic curve of 55 degrees was corrected to 22 degrees (58% correction) at last follow-up and the nonstructural lumbar curve of 31 degrees was corrected to 10 degrees (67% correction) at last follow-up. Preoperative thoracic kyphosis of 28 degrees was improved to 34 degrees at last follow-up. The RVAD were 23 degrees and 13 degrees, preoperatively and postoperatively, respectively. No patient showed a progression of 10 degrees or more in the postoperative coronal curve or RVAD. One patient had a progression of the deformity caudal to the instrumented segments. There were no neurological or screw-related complications. CONCLUSIONS: Posterior segmental pedicle screw fixation in skeletally immature patients with scoliosis may be effective in preventing the crankshaft phenomenon.

Direct Vertebral Rotation (DVR): A New Technique of 3-D Deformity Correction with Segmental Pedicle Screw Fixation in Adolescent Idiopathic Scoliosis (AIS) / 대한척추외과학회지

STUDY DESIGN: A prospective study. OBJECTIVES: To introduce a new technique, direct vertebral rotation (DVR), and to compare the surgical results with those of a simple rod derotation (SRD). SUMMARY OF BACKGROUND DATA: Pedicle screw fixation, with a simple rod derotation maneuver, enables powerful coronal and sagittal plane corrections in scoliosis surgery. However, the ability for rotational correction is still unclear. METHODS: Thirty-eight AIS patients, treated with segmental pedicle screw fixation, were analyzed. The first group (n=17) was treated by DVR, and the second (n=21) by SRD. Having similar preoperative curve patterns, both groups were evaluated for the deformity correction and spinal balance. RESULTS: In the DVR group, the average preoperative AVR of 16.7 degrees was corrected to 9.6 degrees, showing a 42.5% correction, while in the SRD group, the correction was negligible, from 16.1 degrees to 15.7 degrees(2.4%). In the DVR group, the preoperative thoracic curve of 55 degreeswas corrected to 12 degrees(79.6%), and the lumbar curve from 39 degreesto 7 degrees(80.5%). In the SRD group, the preoperative thoracic curve of 53 degreeswas corrected to 17 degrees(68.9%), and the lumbar curve from 39 degreesto 16 degrees(62.2%). The average LIVT correction was 80.6 and 66.3% in the DVR and SRD group, respectively. There were statistically significant differences in the coronal curve, LIVT and rotational correction (p<0.05, Mann-Whitney u test). CONCLUSIONS: The segmental pedicle screw fixation with 'direct vertebral rotation'showed better rotational and coronal corrections than the 'simple rod derotation'.

Experimental Osteoporosis in Tail Suspended Rat / 대한정형외과연구학회지

PURPOSE: To clarify whether the bone resorption in femur measured by the expression of OPG & RANK-L was increased in tail suspended rat. MATERIALS AND METHODS: Four-week-old female Sprague Dawley rats were divided into two groups. The experimental group (n=79) was housed and fed with 2 weeks of tail suspension, and reloaded for 8 weeks without tail suspension. The control group (n=46) was housed and fed for 10 weeks without tail suspension. Bone mineral densities, serum levels of ALP and TRAP were measured in both groups. The expressions of the mRNAs of OPG and RANK-L were analyzed by RT-PCR. RESULTS: The ALP and TRAP were increased in the experimental group during both tail suspension and reloading, which reflected the increased bone metabolism in the experimental group. In femur of the experimental group, the expression of the mRNA of RANK-L was increased during tail suspension, and the expression the mRNA of OPG was decreased. With reloading, the expression of the mRNA of RANK-L in femur was decreased, while the expression of the mRNA of OPG was increased.

Determination of Distal Fusion Level with Segmental Pedicle Screw Fixation in Single Thoracic Idiopathic Scoliosis / 대한척추외과학회지

STUDY DESIGN: Retrospective study. OBJECTIVES: To determine the exact distal fusion level in the treatment of single thoracic idiopathic scoliosis (King III and IV) with segmental pedicle screw fixation and rod rotation. SUMMARY OF LITERATURE REVIEW: Pedicle screw fixation effectively shortens the distal fusion extent by improved 3-D deformity correction. However, the selection of distal fusion extent remains controversial in single thoracic idiopathic scoliosis. MATERIAL AND METHODS: Forty-two single thoracic adolescent idiopathic scoliosis patients subject to segmental pedicle screw fixation and rod rotation with minimum follow-up of 2 years (2-6 years) were analyzed. The patients were grouped according to the distal fusion level with reference to the standing neutral vertebra (NV) for comparison of deformity correction, radiological and clinical spinal balance using standing radiographs. Distal fusion down to NV +1 was in 9 patients, NV in 5, NV-1 in 9, NV-2 in 12 and NV-3 in 7 patients respectively. RESULTS: Preoperative 50+/-11 degrees of thoracic deformity was corrected to 13+/-5 degrees showing 74% of curve correction. Preoperative 23+/-7 degrees of lumbar deformity was corrected to 2+/-8 degrees showing 93% of curve correction. Postoperative adding on deformity was obtained in 14 patients. Significant difference was found not by King classification but by distal fusion level: significantly higher chance of unsatisfactory results from not going to the NV-1 (p=0.001). CONCLUSIONS: In correction of single thoracic idiopathic scoliosis with segmental pedicle screw fixation, the curve should be fused to NV-1 saving one or more motion segments when compared to the fusion to the stable vertebra.

Surgical Treatment of Post-Traumatic Kyphosis with Neurologic Compromised Osteoporotic Fracture: Comparison between Anterior-Posterior Surgery versus Posterior Egg-Shell Procedure / 대한척추외과학회지

STUDY DESIGN: Retrospective study. OBJECTIVES: To compare the surgical results between anterior-posterior surgery and posterior eggshell procedures in post-traumatic kyphosis with neurologic compromised osteoporotic fracture. SUMMARY OF LITERATURE REVIEW: Combined anterior-posterior surgery is usually recommended in cases of kyphotic deformities with neurologic deficit secondary to osteoporosis. However, it is associated with significant morbidity in elderly patients. MATERIALS AND METHODS: Twenty-six post-traumatic kyphosis with neurologic compromised osteoporotic fracture patients subjected to either anterior-posterior surgery (n=11) or posterior egg-shell procedure (n=15) were analyzed. The average age at the operation was 62.6 years (range: 50-82), male : female ratio was 12 : 14, and the average follow up was 2.9 years (range:2.0-4.9). Preoperative interval from injury to operation was 15.4 months (range: 1-36). Thoracolumbar (T12-L1) fracture was in 20 and lumbar fracture was in 6. RESULTS: There was no significant difference in age, sex, preoperative and postoperative Frankel grade, and preoperative vertebral collapse between two groups(p<0.05). In anterior-posterior group, the mean operation time was 351 minutes with a mean blood loss of 2892 ml, and preoperative kyphosis of 22 degrees was corrected to 11 degrees at latest follow-up with 7 cases of neurologic improvement. In the eggshell group, the mean operative time was 215 minutes with blood loss of 1930 ml, and preoperative kyphosis of 34 degrees was corrected to 8 degrees at latest follow-up with 11 cases of neurologic improvement. Egg-shell group showed significantly less operation time and blood loss with beter kyphosis correction. In anterior-posterior group, postoperative pneumonia was developed in 2 and superficial infection in 1. Distal screw loosening was detected in 4, 2 in anterior-posterior group and 2 in posterior eggshell group. One of them was treated by revision and others were treated by brace more than 6 months. CONCLUSIONS: Posterior eggshell procedure showed a better kyphosis correction with significantly less operation time and blood loss. It is a preferable alternative to anterior-posterior surgery in post-traumatic kyphosis with neurologic compromised osteoporotic fracture.

Bending Stiffness of Rod in Pedicle Screw Systems / 대한척추외과학회지

PURPOSE: To measure bending stiffness of rod in pedicle screw systems and identify the optimal rod for surgical correction of spinal deformities. MATERIALS AND METHODS: Bending stiffness of six different rods -7 mm stainless steel, 6 mm titanium alloy, 6.35 mm titanium, 5.5 mm titanium, 6 mm Shape Memory Alloy after martensite temperature, 7 mm Shape Memory Alloy after martensite temperature were measured by MTS 858 Bionix test system according to the ASTM standards. The specimen number was 8 for each rod. Young's modulus of elasticity was calculated from load-displacement data. RESULTS: Seven-mm stainless steel rod was stiffer than any other rods with bending stiffness of 143.7 +/- 3.8 N/mm, and also showed largest Young's modulus of elasticity of 135.1 +/- 3.0 GPa. Six-mm Shape Memory Alloy rod after martensite temperature was most flexible with bending stiffness of 58.1 +/- 2.8 N/mm, and showed smallest Young's modulus of elasticity of 68.0 +/-2.1 GPa. Seven-mm Shape Memory Alloy rod after martensite temperature was similar to the 6.35 mm titanium and 6 mm titanium alloy rod in bending stiffness and Young's modulus of elasticity. CONCLUSION: Seven-mm stainless steel rod was the stiffest rod tested, which is necessary to improve correction rate and maintain achieved correction. However, the rod selection should be individulized since stiffer rod might increase the chance of acute failure. Seven-mm Shape Memory Alloy could be more useful in deformity correction than 6 mm Shape Memory Alloy since it was not only similar to other rods in stiffness but also had shape memory function which would be necessary to establish the desired position of the spine.

Perioperative Complications of Posterior Lumbar Spinal Surgery for Degenerative Lumbar Diseases in the Elderly / 대한척추외과학회지

STUDY DESIGN: A retrospective study of perioperative complications was performed in elderly patients undergoing posterior decompression and fusion for lumbar degenerative conditions. OBJECTIVES: To identify the perioperative complications and to analyze the influence of posterior decompression and fusion on the occurrence of the morbidity. SUMMARY OF BACKGROUND DATA: Because of the better long-term results, the decompression and fusion with instrumentation have been recently recommended for treatment of degenerative lumbar disease in the elderly. However, the perioperative complication rate and their correlating factors have not been adequately defined. MATERIALS AND METHODS: A retrospective review of the medical charts of fifty-one patients aged 65 years or older operated during June 1997 to July 1998 was undertaken. The minimum follow-up required for inclusion was three months. All medical and surgical perioperative complications directly related to the surgical procedure were noted. The association of fusion levels and other factors with the occurrence of perioperative complications were analyzed. RESULTS: Perioperative complications occurred in 17(33.3%) of the 51 patients. Seven patients(13.7%) had at least one major complication, 5(9.8%) had at least one minor complication and 9(17.6%) had insignificant complications. Hematoma and wound infection were the most common surgical complications. Paralytic ileus was the most common medical complication. There was no difference in the rate of perioperative complications between the long and short fusion groups. An age of more than seventy-five years at the time of surgery was associated with a higher risk of complications. There was no statistically significant relationship between the perioperative complications and sex diagnosis, operative time, type of bone grafting, amount of blood transfusion, or preoperative comorbidity of the patients. CONCLUSION: Perioperative complications were quite common in the present series, occurring in 33.3% of the patients. An age over seventy-five years was a risk factor for associated with morbidity. The number of levels fused and the comorbidity did not associated the development of the complications.

Comparison of Multiple Hook and Pedicle Screw Fixation in Congenital Scoliosis Treated by Combined Anterior and Posterior Fixation / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study. OBJECTIVES: The purpose of the study was to determine the efficacy of pedicle screw fixation in treatment of congenital scoliosis. SUMMARY OF BACKGROUND DATA: Surgical correction of rigid congenital scoliosis often ends up in less than satisfactory results. Pedicle screw fixation, enabling a rigid fixation with improved holding power may enhance the correction of these tenacious deformities. METHODS: Twenty one congenital scoliosis treated by combined anterior release and posterior correction were analyzed after minimum follow up of 2 years (range 2-9 years). There were 11 males and 10 females. The mean age was 21.1 years (range: 11.2-29.4 years). They were divided into two groups by the posterior fixation method used. The group treated by multiple hook fixation (HF) comprised 11 patients with an index curve of 67+/-2 0degree. The group by multiple pedicle screw fixation (SF) comprised 10 patients with an index curve of 61+/-26degree. There was no statistical difference in the preoperative index curve characteristics between the two groups. RESULTS: Immediately after the surgery, the mean index curve was 37.0degreein the HF group and 29.9degreein the SF group showing a correction of 44.7+/-19% and 49+/-17% respectively. At the final follow up, the curve was 46.9degreein the HF group and 32.3degreein the SF group showing a loss of correction of 21+/-22% and 7+/-2% respectively. CONCLUSIONS: Pedicle screw fixation is an effective method of treating congenital scoliosis, offering an improved correction and maintenance.

Measurement of Proximal Humerus in Korean Adult Skeleton / 대한정형외과학회잡지

PURPOSE: To obtain basic anatomical data of proximal humerus of Korean adult skeleton. MATERIALS AND METHODS: Fifty-two dry humeri of Korean adults were measured with a caliper and goniometer. Measured parameters were retroversion, angle of the bicipital groove, bicipital groove-shaft angle, neck-shaft angle, diameters of the humeral head, dimension of the greater tuberosity, distance between humeral head and greater tuberosity, and length of the humerus. All of the eight parameters were measured twice. The correlations between retroversion and diameters of the humeral head, retroversion and length of the humerus, retroversion and angle of the bicipital groove, diameters of the humeral head and length of the humerus were analyzed by student t-test using SAS system. RESULTS: Retroversion was 34.2 degree with high individual variation, ranging from 17.0 degree to 50.0 degree. The angle of the bicipital groove was 36.2 (22.0-54.0) degree. The bicipital groove-shaft angle was 7.4 (1.0- 16.0) degree. The neck-shaft angle was 136.3 (120.0-150.0) degree. The superior-inferior diameter of the humeral head was 43.3 (35.5-52.0) mm, and anterior-posterior diameter was 39.9 (33.5-46.0) mm. The dimension of the greater tuberosity was 29.8 (19.0-46.0) mm, and the distance between humeral head and greater tuberosity was 7.9 (4.5-12.0) mm. The length of the humerus was 303.7 (265.0-388.0) mm. There was significant correlation between the head diameters, the retroversion, and the length, but no correlation between the retroversion and the angle of the bicipital groove. CONCLUSIONS: It is suggested that high individual variation of retroversion should be considered in case of arthroplasty. The humeral head was elliptical in shape. The mean narrow diameter of the humeral head was about 40 mm. The greater tuberosity was about 30 mm in dimension, and located 8 mm inferior to the humeral head. The bicipital groove was not a reliable reference in determining retroversion.

Restoration of Thoracic Kyphosis in Idiopathic Scoliosis-A Comparison between Multiple Hook and Segmental Pedicle Screw Fixation in Adolescent Idiopathic Scoliosis(AIS) / 대한척추외과학회지

STUDY DESIGN. This is a retrospective study. OBJECTIVES. To verify the advantage of segmental pedicle screw fixation in restoration of thoracic kyphosis in hypokyphotic patients. SUMMARY OF BACKGROUND DATA. Restoration of thoracic kyphosis is essential for a satisfactory three dimensional correction in thoracic AIS. However, with significant preoperative hypokyphosis, the result of multiple hook fixation was often unsatisfactory. METHODS. Fifty-one patients with thoracic AIS treated by posterior instrumentation and followed up for more than 2 years were divided into 3 groups each comprising 17 patients. Hypokyphosis- Hook(HH) group comprised patients with thoracic kyphosis less than 15degrees treated by multiple hooks. Hypokyphosis-Screw(HS) group comprised hypokyphotic patients treated by segmental pedicle screws. Normal kyphosis-Screw(NS) group comprised patients with kyphosis greater than 15degrees treated by segmental pedicle screws. Preoperative thoracic kyphosis was 4.1+/-8.6degrees, 8.1+/-5.6degrees and 27.3+/-9.8degrees in the HH, HS and NS group respectively. There was no significant difference between the HH and HS groups(p=0.39). Three groups were compared for restoration of thoracic kyphosis. Results. At the final follow up, the thoracic kyphosis was 14.5+/-10.2degrees, 27.3+/-11.3degrees and 28.3+/-3.7degrees in the HH, HS group and NS group showing correction of 10.0+/-10.0degrees, 19.2+/-14.0degrees and 0.4+/-12.3degreesrespectively. There was a significant difference between HH and HS group(p=0.0008). However there were no difference between tile HS and the NS group(p=0.8). CONCLUSIONS. Segmental pedicle screw fixation was more effective than multiple hooks in restoring the thoracic kyphosis in AIS patients with hypokyphosis. The restored kyphosis was similar to that obtained in patients without hypokyphosis.

Treatment of Fixed Lumbosacral Kyphosis by Posterior Vertebral Column Resection: A preliminary report / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study evaluating the efficacy of new surgical technique for treatment of fixed lumbosacral kyphosis. OBJECTIVES: To report a new method of vertebral column resection and to determine its efficacy in the treatment of fixed lumbosacral kyphosis. SUMMARY OF BACKGROUND DATA: The treatment of fixed severe spinal deformity is very difficult and only a few surgical methods are reported. The vertebral column resection from anterior and posterior is a radical method to treat the severe deformity but it has many problems with anterior and posterior approachs. MATERIALS AND METHODS: A new surgical method of vertebral column resection from posterior approach only(PVCR) was carried out in 5 patients of fixed lumbosacral Tb kyphosis from October 1997 to March 1998. The mean age was 43.4 years(range 35-61 years), and four were female and one male. The average postoperative follow-up period was 5.5 months(ranged from 2 months to 12 months). An average of 2.6 vertebrae was resected. The degree of sagittal curves was measured using the Cobb technique preoperatively and postoperatively. the rejional lumbosacral kyphotic angle and compensatory thoracic curvature from 74 to 712. The sagittal imbalance was measured by distance from C7 plumb line to postero-superior corner of 51 using 14 x 36 inch standing lateral radiograph. RESULTS: The sagittal deformities were corrected from an average of kyphosis 37.4 to lodosis 8.4 at lumbosacral level and from an average of lodosis 31.6 to lodosis 8.2 at thoracic level. The sagittal imbalance was improved from an average of +11.7cm to +2.2cm, for a posterior immigration of 9.5cm. The mean operating time was 334 minutes and with an average blood loss of 4338m1. Complication comprised of motor weakness with deep wound infection in one case and superficial wound infection in another case. The transient hip flexor weakness was seen in all the patients. The hip flexor power recovered in 3-4 weeks. The patient of motor weakness and deep infection showed partial motor improvement and complete wound healing at last 2 month follow-up. CONCLUSION: one-stage posterior vertebral column resection is a promising technique for treatment of the severe fixed lumbosacral kyphosis.

Arthroscopic Revision Anterior Cruciate Ligament Reconstruction: Report of 5 Cases / 대한정형외과학회잡지

From March 1992 to June 1994, we experienced five failed cases of anterior cruciate ligament reconstruction. Four out of five cases had reconstruction in other hospitals. Two of them had anterior cruciate ligament reconstruction using artificial ligament, one using bone-patellar tendon-bone auto- graft, and one using bone-patellar tendon-bone autograft augmented by artificial ligament. The remaining one case had arthroscopic anterior cruciate ligment reconstruction using bone-patellar ten- don-bone autograft in Asan Medical Center. We performed arthroscopic revision anterior cruciate ligament reconstruction using allograft in four cases and bone-patellar tendon-bone autograft in one case. All cases were treated with vigorous postoperative rehabilitation program including postoperative immediate range of motion(ROM) exercise and muscle strengthening exercise. Postoperative results were evaluated by Lysholm knee score in average 17.2 months(range from 12 months to 25 months). The average Lysholm score improved from 49.8 to 81.4. At follow-up study, anterior drawer test with Telos device revealed 2mm of average side to difference.