Epidemiology of the Spinal Cord and Cauda Equina Injury in Korea: Multicenter Study

STUDY DESIGN: Multi-center study, questionnaire survey. OBJECTIVES: To offer a database of spinal cord injury (SCI) by reviewing statistics and literatures of other countries, investigating the overall mechanism, injury patterns and treatment of SCI. SUMMARY OF LITERATURE REVIEW: There are no preexisting domestic studies (collectively conducted by multi-centers) of the prevalence and treatment of SCI. MATERIALS AND METHODS: From September 2006 to August 2009, 47 cases of SCI in 6 universities were investigated retrospectively. 17 questionnaire contents including the courses of injury-to-treatment were studied with data gathered from surveys. RESULTS: The average age of patients was 48.4-years-old, male to female ratio was 33 to 14. The cases of falling from a height were 22 cases (47%), lumbar area 19 cases (40%), and unstable bursting fracture 24 cases (51%) the most. Complete and incomplete paralyses were 19 cases (40%) and 28 cases (60%), respectively. High dose steroids were injected in 16 cases (NASCIS II) and 9 cases (NASCIS III). 14 cases presented complications and operations were performed 46 cases (98%). 12 cases (26%) arrived at the hospital within 4 hours of injury, 11 cases (23%) in 8 hours. On the way to the hospital, proper emergency treatment was performed in 25 cases (53%), and 30 cases (64%) had a clear understanding of SCI after the final diagnosis. CONCLUSIONS: This is the first study that offers a comprehensive database of spinal cord injury (SCI), by investigating the overall mechanism, injury patterns, and treatment of SCI; this study is expected to be used in the future as an important reference material for spinal cord injury statistics and a standard for care.

The Comparision of Mitigative Effect of Alendronate and Risedronate on Particle-Induced Osteolysis: in Mouse Calvarian Model / 대한정형외과연구학회지

PURPOSE: The purpose of this study was to compare the mitigative effect of alendronate and risedronate on osteolysis in the mouse calvarian model by using titanium (Ti) and polymethylmethacrylate (PMMA) particles. MATERIALS AND METHODS: Experimental mice (male C57/BL6) are divided into three groups; control, Ti particle-treated and PMMA particle-treated group. Each Ti and PMMA particle-treated group was divided into three subgroups which received no bisphosphonates, which received alendronate, and which received risedronate. We measured number of osteoclast, area of osteolysis, bone and soft tissue thickness, ratio of bone and total tissue on mid-sagittal suture area (MSSA) and compared between two groups. RESULTS: Both alendronate and risedronate had significant inhibitory effect on Ti or PMMA particle-induced osteolysis in mouse calvarian model (p<0.05). Furthermore, bisphosphonates prevented formation of particleinduced osteolysis as RANK/Fc. Risedronate had better capability for preserving bone thickness in PMMA treated mice and also showed decreased soft tissue thickness in Ti treated mice than alendronate (p<0.05). CONCLUSION: Both alendronate and risedronate may be an effective agents on mitigation of Ti and PMMA particle-induced osteolysis. However, risedronate showed better structual bone preserving capacity than alendronate in particle-treated mouse calvariae.

The Effect of Posterior Lumbar Interbody Fusion After Posterolateral Fusion in Degenerative Spondylolisthesis / 대한정형외과학회잡지

PURPOSE: To determine the necessity of an additional posterior lumbar interbody fusion (PLIF) after a posterolateral fusion (PLF) for the treatment of degenerative spondylolisthesis (DS). MATERIALS AND METHODS: A retrospective study, after a minimum follow-up of 2 years was conducted on forty patients who underwent a single level decompression and instrumented fusion for DS with spinal stenosis at the L4-5 level. A PLF was performed in 21 patients, and a circumferential fusion (CF) with an additional PLIF in 19 patients. According to the fusion methods and preoperative segmental mobility, the patients were divided into four groups; s-PLF group (PLF in the stable group, n=13), s-PLIF group (CF in the stable group, n=11), u-PLF group (PLF in the unstable group, n=8), and u-PLIF group (CF in the unstable group, n=8). Clinical and radiographic comparisions between the PLF and PLIF groups were performed. RESULTS: The mean decrements of Oswestry Disability Index (Visual Analog Scale) scores were 29% (5.5), 29% (5.9), 22% (2.6) and 42% (5.9) respectively for the s-PLF, s-PLIF, u-PLF and u-PLIF groups, and a statistical difference was found only between the u-PLF and u-PLIF groups (ODI: p=0.032, VAS: p=0.004). Fusion rates were 92%, 100%, 88% and 100% respectively. The mean slip angle increments were serially 2.5 degrees, -3.1 degrees, -1.5 degrees and -0.3 degrees, and the mean percent slip decrements were 6.7%, 8.7%, 5.1% and 3.7%, and the mean disc height increments were -0.4 mm, 1.8 mm, 0.5 mm and 3.0 mm, and the mean lumbar lordosis increments were 8.6 degrees, 4.7 degrees, -1.9 degrees and 1.9 degrees and the mean sacral tilt increments were 3.8 degrees, 3.4 degrees, -1.3 degrees and 0.9 degrees. Statistical differences were found only between the s-PLF and s-PLIF groups in slip angle increments (p=0.029) and between the s-PLF and s-PLIF groups (p=0.043) and between the u-PLF and u-PLIF groups (p=0.042) in disc height increments. CONCLUSION: PLF alone provided successful clinical outcome in stable group, but CF provided better clinical outcomes in the unstable groups. This study suggests that preoperative segmental mobility may be a criterion to determine whether or not an additional PLIF is necessary in the treatment of lumbar DS.

Snapping Metacarpo-Phalangeal Joint after Depressed Fracture of Metacarpal Neck: Case Report

We report one case of snapping metacarpo-phalangeal joint after depressed fracture of metacarpal neck which could be diagnosed by exploration for the snapping during extension in spite of conservative treatments.

Effects of Polyphosphate on the Fusion of Rabbit Lumbar Spine / 대한척추외과학회지

STUDY DESIGN: Posterior and posterolateral fusions were performed in rabbit lumbar spines. OBJECTIVES: To investigate the osteoinductive effect of polyphosphates. SUMMARY AND LITERATURE REVIEW: Inorganic polyphosphates are known to be rich in osteoblasts and involved in the mineralization process in bone metabolism. However, no study has been undertaken to investigate the osteoinductive effect of polyphosphates. MATERIALS AND METHODS: Forty adult New Zealand white rabbits underwent monolevel lumbar fusions, and were divided into two groups according to the fusion beds: twenty each between the laminae (posterior fusion group, PF group) and between the transverse processes (posterolateral fusion group, PLF group). In ten of twenty rabbits in the PF group, 0.8gm of autogenous iliac bone was grafted onto the right sides of the laminae, which were used as a control group (C1), with 0.4gm autogenous bone immersed in polyphosphate solution in the left sides as an experimental group (E1). In the other ten, 0.8gm of autogenous bone was grafted onto the right sides (C2) and 0.8gm of tricalcium phosphate porous blocks containing polyphosphate in the left sides (E2). The other twenty rabbits of the PLF group were similarly divided into C1, E1, C2 and E2 groups by grafting the same amount of materials between the transverse processes. The animals were sacrificed at the 16th postoperative week and the fusions evaluated grossly, radiologically and histologically. Statistical differences between the groups (C1 vs. E1, C2 vs. E2 and E1 vs. E2) in each of the PF and PLF groups were compared by chi-square tests. RESULTS: The fusions were finally determined by the gross finding using manual palpation. In the PF group, bony fusions were obtained in 90, 80, 90 and 70% of the C1, E1, C2 and E2 groups, respectively. In the PLF group, these were 80, 70, 60 and 0% of the C1, E1, C2 and E2 groups, respectively. Statistical analysis revealed differences only between C2 and E2 (p=0.005), and between E1 and E2 (p=0.002) of the PLF group. Histologically, beta-tricalcium phosphate particles containing polyphosphate were transformed into the osteoid in some areas of the PLF-E2 group, although only fibrous unions were obtained grossly. CONCLUSIONS: It is suggested that the polyphosphate may have an osteoinductive effect, even though the osteoinductive potency was very week in this fusion model of the rabbit lumbar spine. Therefore, further explorations, such as the threshold and optimal concentrations of polyphosphate in vivo and the best carrier material of polyphosphate, should be performed to obtain the optimal conditions for fusion.

Avulsion Fracture of Calcaneus in Diabetic Patients

Avulsion fracture of the calcaneal tuberosity is an uncommon injury. Usually it occurs from indirect trauma, and can be seen in old patients with osteoporosis or in patients with diabetic neuropathy. Follow-up studies showed fracture healing in most cases, but skeletal deformity may develop in some cases. Therefore we should do plain X-ray evaluations in diabetic patients with foot and ankle pain, even though there have been no definite trauma history. Four cases of calcaneus avulsion fracture were treated operatively in diabetic patients, and reported.

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.

Technique of Pedicle Screw Fixation and Derotation for the Improvement of Rotational Deformity in Scoliosis Surgery:Derotation:Screw Rotation / 대한척추외과학회지

STUDY DESIGN: This is a prospective design. SUMMARY AND BACKGROUND DATA: Derotation makes powerful coronal and satisfactory sagittal correction, however, making rotational correction is still controversy. OBJECTIVES: To introduce a new technique to improve the vertebral rotation. METHODS: 1. Fix the pedicle screws of concave side of thoracic spine with nut driver or derotator before derotation maneuver. 2. During the derotation (counter-clockwise), rotate the nut driver/derotator to the opposite direction (clockwise). RESULTS: A King type II AIS girl with the magnitude of right thoracic and left lumbar curve was 54 degrees and 40degress respectively was reviewed. Thoracic apical rotation was checked 32 degrees. When derotation maneuver was done, the Cobbs angle of thoracic verteba was corrected to 14 degrees (74.1%), however the apical angle was aggravated to 34 degrees . When derotation-screw rotation(DSR) was done, thoracic angle was corrected to 3 degrees with 94.4% of curve correction. The apical rotation was improved to 25 degrees. Preoperative 19.6 degrees of RAsac was corrected to 10.4 degrees showing 46.9% of correction. Postooperatively she was balanced inspite of overcorrection. CONCLUSION: Derotation itself did not improve or slightly aggravate the rotation of apical vertebra. Apical rotation was dramatically improved by derotation combined by screw rotation technique. Maximal curve correction was obtained without trunk decompensation. This new technique may replace the advantages of anterior instrumentation in better rotational correction and saving fusion levels.

Decompensation in Selective Thoracic Fusion by Segmental Pedicle Screw Fixation in King type II Adolescent Idiopathic Scoliosis (AIS): Causative Factors and its Prevention / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To find the causative factors which induce decompensation after selective thoracic fusion with segmental pedicle screw fixation in King type II AIS. SUMMARY OF LITERATURE REVIEW: Pedicle screw fixation enabling enhanced correction is increasing in use in idiopathic scoliosis. However, there are few reports on the decompensation after selective thoracic fusion with pedicle screw fixation in King type II AIS. MATERIALS AND METHODS: Thirty-nine King type II AIS patients subjected to selective thoracic fusion with pedicle screw fixation were analyzed after a minimum follow up of 1 year. They were reviewed using standing roentgenograms. Deviation of center of T1 from center sacral line greater than 2 cm was considered decompensation. RESULTS: Among 39 patients, compensation was in 35 while decompensation in 4 postoperatively. There was no significant differences between the two groups in preoperative thoracic or lumbar curve characteristics such as curve magnitude, apical deviation or apical rotation. There was a significant difference in thoracic curve correction and postoperative T-curve magnitude divided by preoperative L-curve respectively(p= 0.001). CONCLUSION: Decompensation with selective thoracic fusion with segmental pedicle screw fixation in King type II AIS was not induced by preoperative L-curve characteristics nor derotation maneuver. The factor of decompensation was overcorrection, i.e. if thoracic curve correction was more than 75% or if the magnitude of postoperative T-curve was 30% less than that of preoperative L-curve, there was a high risk of decompensation.