Oxford Cobbometer Versus Computer Assisted-Software for Measurement of Cobb Angle in Adolescent Idiopathic Scoliosis.

OBJECTIVE: The objective was to compare Cobb angle measurements performed using an Oxford Cobbmeter and digital computer software (Surgimap) in a series of 83 adolescent idiopathic scoliosis (AIS) patients. METHODS: Two independent observers measured the Cobb angles for 123 curves on 83 consecutive long radiographs of patients with AIS using both Oxford Cobbmeter and digital computer software (Surgimap). The measurements were repeated a week. Curves were classified according to the severity into mild, moderate, and severe. The results were statistically analyzed for intraobserver and interobserver reliability. RESULTS: The mean Cobb angle was 48.12° ± 19.75° (range, 10.54°-110.76°). Globally the results of curve measurements were comparable between and within both observers using both methods, with small mean differences. According to intraclass correlation coefficient, there was high inter- and intraobserver high agreement for both methods. All readings were > 0.9. There was a good interobserver (κ = 0.745, 0.693) and a very good interobserver agreement (κ = 0.810, 0.804) for both methods for curve classification. However, poor agreement was observed as regards to the measurement time, being less with Oxford Cobbometer. CONCLUSION: The results of this study indicate that the Surgimap digital computer software measurement is an equivalent measuring tool to the Oxford Cobbmeter in Cobb angle measurement. Both have high intra and interobserver agreement for measurement and for curve classification, with small measurement differences. Oxford Cobbmeter is advantageous in being quicker, and therefore it is the method of choice for manual measurement, where PACS (patient archiving and communication system) or digital system is not available.

Endplate Changes with Polyetheretherketone Cages in Posterior Lumbar Interbody Fusion.

STUDY DESIGN: A retrospective radiographic analysis. PURPOSE: The aim of the current study is to assess endplate changes after the use of polyetheretherketone (PEEK) cages in posterior lumbar interbody fusion (PLIF). OVERVIEW OF LITERATURE: A few recent reports had revealed endplate abnormalities due to PEEK cages, which may lead to nonunions. METHODS: A retrospective computed tomography (CT)-based analysis of the endplate cavities and fusion status following PLIFs with PEEK cages was conducted by two independent observers. The term "cavity" was used to describe the endplate changes. The vertebral endplate cavities were assessed according to the size, multiplicity, location, and presence or absence of sclerosis. RESULTS: There were 86 fixed levels in 65 consecutive patients, with a mean age of 35.44±19.60 years. The mean follow-up was 16.5±10.1 months (range, 6-57 months). Definite fusion was seen in 56 levels (65.12%) by observer 1 versus 44 levels (51.16) by observer 2. The strength of agreement was moderate. Endplate cavities were observed in 42 levels (48.84%) by observer 1 versus 47 levels (54.65%) by observer 2, with fair agreement. The strengths of agreement for the locations, multiplicity, and size were moderate, fair, and poor, respectively. Neither age, sex, etiology, levels, nor follow-up period was significantly associated with the presence of cavities. With regard to fusions, the nonunions detected by observer 1 were significantly associated with the presence of cavities (p<0.0001). However, those detected by observer 2 were nearly significant (p=0.05). CONCLUSIONS: There was a high rate of unfavorable radiographic findings in the form of endplate cavities in PLIF cases with PEEK cages. A more comprehensive classification for the assessment of fusions and endplate cavities should be formulated. We strongly recommend further CT-based studies with larger sample size and longer follow-up periods.

Two-body wear behavior of human enamel versus monolithic zirconia, lithium disilicate, ceramometal and composite resin.

PURPOSE: To investigate and compare the surface roughness (SR), weight and height of monolithic zirconia (MZ), ceramometal (CM), lithium disilicate glass ceramic (LD), composite resin (CR), and their antagonistic human teeth enamel. MATERIALS AND METHODS: 32 disc shaped specimens for the four test materials (n=8) and 32 premolars were prepared and randomly divided. SR, weight and height of the materials and the antagonist enamel were recorded before and after subjecting the specimens to 240,000 wear-cycles (49 N/0.8 Hz/5℃/50℃). SR, height, weight, and digital microscopic qualitative evaluation were measured. RESULTS: CM (0.23 + 0.08 µm) and LD (0.68 + 0.16 µm) exhibited the least and highest mean difference in the SR, respectively. ANOVA revealed significance (P=.001) between the materials for the SR. Paired T-Test showed significance (P<.05) for the pre- and post-SR for all the materials. For the antagonistic enamel, no significance (P=.987) was found between the groups. However, the pre- and post-SR values of all the enamel groups were significant (P<.05). Wear cycles had significant effect on enamel weight loss against all the materials (P<.05). CR and MZ showed the lowest and highest height loss of 0.14 mm and 0.46 mm, respectively. CONCLUSION: MZ and CM are more resistant to SR against the enamel than LD and CR. Enamel worn against test materials showed similar SR. Significant variations in SR values for the tested materials (MZ, LD, CM, and CR) against the enamel were found. Wear simulation significantly affected the enamel weight loss against all the materials, and enamel antagonist against MZ and CM showed more height loss.

The Sagittal Thoracic Modifier Component of the Lenke Classification System in Moderate and Severe Adolescent Idiopathic Scoliosis: Reliability and Reproducibility of Measurements Among 5 Observers.

STUDY DESIGN: A prospective radiographic study. SUMMARY OF BACKGROUND DATA: As the importance of the spinal sagittal profile becomes increasingly evident, there is a need to ensure that the measuring methods used to evaluate thoracic kyphosis (TK) are both accurate and reproducible. OBJECTIVE: The purpose of the following study was to determine the intraobserver and interobserver variability of measurements of the sagittal profile in moderate and severe thoracic scoliosis. METHODS: Five experienced Faculty Spine surgeons independently reviewed thirty standing long 30-inch cassette lateral radiographs of preoperative moderate and severe curves ≥50 degrees of adolescent idiopathic scoliosis (AIS) patients on 2 different occasions. The parameters measured were the vertebral endplate clarity and measurability of the sagittal angle from D5 to D12 and categories of thoracic sagittal modifier. κ statistics and Intraclass Correlation Coefficient (ICC) were used for analysis. RESULTS: The interobserver percentage of agreement for the Sagittal modifier was 58% in both trials. The mean κ coefficient value was only moderate 0.43 (range, 0.14-0.66) for both trials. The number of the vertebral endplates that were difficult to identify was 201 of 300 measurements (67%). There was a predominance of difficulty to identify vertebral endplate clarity in all curve types. CONCLUSIONS: The results of this study yielded poor to moderate interobserver reliability of the thoracic sagittal profile component of the Lenke classification system in moderate and severe AIS. This was attributed to the difficulty in identification of the vertebral endplates. The current standard lateral radiographs routinely used in AIS patients have inherent difficulties and limitations to visualize, identify, and analyze the thoracic endplates in moderate and severe curves.

The Outcome of Radiofrequency Kyphoplasty in the Treatment of Vertebral Compression Fractures in Osteoporotic Patients.

STUDY DESIGN: Retrospective study. PURPOSE: The study aims to assess the effectiveness and safety of radiofrequency (RF) kyphoplasty in the treatment of vertebral compression fractures (VCFs) in osteoporotic patients. OVERVIEW OF LITERATURE: Vertebroplasty and balloon kyphoplasty are established procedures for the treatment of osteoporotic VCFs. However, RF kyphoplasty is a new method which controls cement viscosity. METHODS: We reviewed the results of 41 consecutive patients with 23 thoracic and 38 lumbar VCFs who underwent RF kyphoplasty. The study population included 14 males (34%) and 27 females (66%). The mean patients age was 78 years (range, 51-89 years), and the follow-up period was 1 year. Clinical and radiographic analyses were performed during follow-up at 6 weeks, 6 months, and 1 year. All patients were assessed clinically pre- and postoperative using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Radiological assessment with X-ray in two views preoperatively, postoperatively, and during follow-up visits. RESULTS: The mean preoperative VAS was 8.7 (range, 5-10; standard deviation [SD], 1.2). Postoperatively, VAS decreased by 3.3 (range, 2-5; SD, 0.9). At the end of the follow-up, VAS decreased by 1.22 (range, 0-7; SD, 1.6). The mean preoperative ODI score was 85.9, decreasing to 9.6 postoperatively and improving to 18.4 during the 1-year follow-up. The mean local kyphotic angle was 9.04° before the procedure and decreased by a mean of 6.16° after the operation and at the end of the follow-up. The mean increase in vertebral body height was 3.3 mm postoperatively and after 1-year follow-up. The rate of cement leakage was 8% (five out of 61 levels of fracture). CONCLUSIONS: RF kyphoplasty is a safe and effective augmentation technique with an advantage of controlling the cement viscosity to minimize the risk of cement leakage. It also shortens operation time.

Comparison between Oxford Cobbmeter and digital Cobbmeter for measurement of Cobb angle in adolescent idiopathic scoliosis.

PURPOSE: The purpose of this study was to compare Cobb angle measurements performed using an Oxford Cobbmeter and digital Cobbmeter in a series of 20 adolescent idiopathic scoliosis (AIS) patients. METHODS: Four observers measured major Cobb angles on 20 standing postero-anterior radiographs of AIS patients with both Oxford Cobbmeter and digital Cobbmeter (iPhone Cobbmeter Application). The measurements were repeated a week after the original measurements. RESULTS: The mean Cobb angle in this study was 43.6° ± 23.62°. The mean measurement time for an observer to measure the 20 Cobb angles was 24.9 min for the smart phone compared with 25.6 min for the Oxford Cobbmeter. The 95 % confidence interval for differences between smart phone and Oxford Cobbmeter measurements on the same radiograph was ±3.68°. The intra-observer variability of the smart phone is equivalent to the Oxford Cobbmeter. The 95 % confidence intervals for inter-observer error were ±5° and ±5.8° for the smart phone and Oxford Cobbmeter, respectively. CONCLUSIONS: We conclude that the smart phone with integrated Tiltmeter and Cobbmeter application is an equivalent Cobb measurement tool to the Oxford Cobbmeter. The advantages of smart phone are the accuracy of determining the most inclined vertebrae and accordingly more precise Cobb angle measurement. The new smart phones with these integrated applications may be really helpful to the spine surgeons, especially in hospitals where PACS or Oxford Cobbmeter is not available.

Computer tomography assessment of pedicle screw placement in thoracic spine: comparison between free hand and a generic 3D-based navigation techniques.

INTRODUCTION: Although pedicle screw fixation is a well-established technique for the lumbar spine, screw placement in the thoracic spine is more challenging because of the smaller pedicle size and more complex 3D anatomy. The intraoperative use of image guidance devices may allow surgeons a safer, more accurate method for placing thoracic pedicle screws while limiting radiation exposure. This generic 3D imaging technique is a new generation intraoperative CT imaging system designed without compromise to address the needs of a modern OR. AIM: The aim of our study was to check the accuracy of this generic 3D navigated pedicle screw implants in comparison to free hand technique described by Roy-Camille at the thoracic spine using CT scans. MATERIAL AND METHODS: The material of this study was divided into two groups: free hand group (group I) (18 patients; 108 screws) and 3D group (27 patients; 100 screws). The patients were operated upon from January 2009 to March 2010. Screw implantation was performed during internal fixation for fractures, tumors, and spondylodiscitis of the thoracic spine as well as for degenerative lumbar scoliosis. RESULTS: The accuracy rate in our work was 89.8 % in the free hand group compared to 98 % in the generic 3D navigated group. CONCLUSION: In conclusion, 3D navigation-assisted pedicle screw placement is superior to free hand technique in the thoracic spine.

Obscure pathology of pulled elbow: dynamic high-resolution ultrasound-assisted classification.

AIM: Pulled elbow or nursemaid's elbow is a radial head subluxation caused by a sudden pull on the extended pronated forearm. Children with pulled elbow usually respond dramatically for reduction, yet others show delayed improvement with no clear pathologic explanation. The aim of our study is to propose an explanation for the varying clinical response after the reduction of pulled elbow aided by ultrasound classification of the underlying pathology and its impact on management. PATIENTS AND METHODS: Fifty children with a mean age of 3.8 ± 1.1 (standard deviation [SD]) years with pulled elbow were scanned by static and dynamic ultrasound utilizing the other elbow as the standard. The radial annular ligament (RAL) was examined for integrity and interposition, with measurement of the radiocapitellar distance. Reduction was performed following the hyperpronation technique, and postreduction splinting was guided by ultrasound findings. Postreduction scans and 1-year follow up were performed. RESULTS: Of the 50 included children, 39 (78%) had intact, yet interposed annular ligament (classified as type I) and 11 (22%) had torn annular ligament (classified as type II). The latter underwent splinting for 7 days. Three out of the 50 children had recurrent subluxation and constituted false-negative cases for the detection of torn ligament and represented the reoccurrence rate of 6%. The sensitivity, specificity, and accuracy for the ultrasound diagnosis of torn RAL were 76.9, 92.3, and 92%, respectively. CONCLUSION: PULLED ELBOW IS CLASSIFIED AS FOLLOWS: type I, with an interposed RAL, and type II, with torn ligament.

Traumatic subdural hematoma of the thoraco-lumbar junction of spinal cord.

BACKGROUND: Spinal subdural hematoma (SSDH) is an exceedingly uncommon and potentially neurologically devastating condition. Recognition of blood products in magnetic resonance imaging is a very important clue for the diagnosis of SSDH. It is generally agreed that prompt surgical evacuation should be performed before irreversible damage to the spinal cord occurs. However, conservative treatment still plays a role in the management of SSDH. OBJECTIVES: To describe the clinical presentation, characteristic MRI findings, and treatment of traumatic SSDH. METHODS: A case of traumatic SSDH at the thoraco-lumbar junction. RESULTS: Magnetic resonance imaging findings of high signal intensity lesion in both T1 and T2 sequences suggest the possibility of subdural hematoma although it may be mistaken for tumorlike cystic lesion of the cord. Although there is a place for conservative treatment of subdural hematoma, we believe that rapid surgical drainage of the subdural hematoma will be associated with the best prognosis especially in the cervical, thoracic, and thoraco-lumbar junctions of the spinal cord. CONCLUSIONS: Rapid surgical drainage of traumatic SSDH affecting the thoraco-lumbar junction of the cord will be associated in most of the cases with rapid neurologic recovery.

Reoperation rate after instrumented posterior lumbar interbody fusion: a report on 1680 cases.

STUDY DESIGN: Retrospective study on the incidence of reoperation in patients previously treated by instrumented posterior lumbar interbody fusion. OBJECTIVES: To answer the following questions: Reoperation rate after PLIF? And is there any influence of the length of fusion on the reoperation rate? SUMMARY OF BACKGROUND DATA: The use of different techniques demonstrates that there is currently no ideal procedure for lumbar fusion. The instrumented posterior lumbar interbody fusion (PLIF) shows a comparable success rate to the so-called 360 degrees fusion techniques (combined dorsoventral spondylodesis) without the need of an anterior approach. METHODS: We reviewed 1680 patients who underwent a PLIF at our institution between January 1995 and December 2000. A total of 3053 levels were fused. The reoperation rate was analyzed. The mean follow-up was 5 years. RESULTS: There were 221 (13.2%) reoperations in 206 patients (12.2%). Of 1680 PLIFs, 312 were multisegmental (>2 segments). Within this group, 45 (14.4%) revisions were done. We found that the most important difference between the multisegmental PLIFs and the mono- or bisegmental PLIFs is the rate of adjacent segment decompensation (5.1% vs. 2.3%), and this was statistically significant. The reoperation rate between those two groups was only slightly different with 12.9% for mono- or bisegmental and 14.4% for multisegmental PLIFs. CONCLUSIONS: The fusion length does not show a significant difference in the reoperation rate as such. Nevertheless, we registered a significantly higher incidence for decompensation of adjacent segments after multisegmental PLIFs.