Reliability analysis of Cobb measurement in degenerative lumbar scoliosis using endplate versus pedicle as bony landmarks.

OBJECTIVES: Degenerative changes of endplates in older patients and tilting of vertebral body in lumbosacral lordosis could make an accurate identification of endplates for the Cobb measurement difficult. Pedicles have been proposed as alternative landmarks because they are usually better visualized, and offer similar clinical validity to the endplates. The objective of this study was to investigate the reliability of the pedicle method of Cobb measurement in degenerative lumbar scoliosis and compare it with the traditional endplate method. METHODS: Two hundred and eighty-four radiographs of degenerative lumbar scoliosis were evaluated. The radiographs were classified into groups based on the patient's age (< 60 years, 60 to 80 years, and > 80 years), level of lower end vertebra (LEV) (LEV at L5, and LEV at or above L4), and curve severity (< 20°, 20° to 40°, and > 40°). Three observers independently measured the radiographs using the endplate and pedicle methods twice with an interval of 1 week. The intra- and interobserver reliabilities were calculated using intraclass correlation coefficients (ICC). RESULTS: The intra- and interobserver ICC values were better for all observers in the > 80 years age group using the pedicle method. The intraobserver ICC values of pedicle method were also better in the LEV at L5 group, and the interobserver ICC values showed a slightly better consistency with the pedicle method. For patients with > 40° curves, the intraobserver ICC values for all observers as well as interobserver ICC values were better using the endplate method. CONCLUSION: The reliabilities of the endplate and pedicle methods for degenerative lumbar scoliosis were both excellent. The pedicle method might be better in older patients (> 80 years) and those with LEV at L5; while the endplate method could have some strength in severe cases (> 40°).

Application of a narrow-surface cage in full endoscopic minimally invasive transforaminal lumbar interbody fusion.

BACKGROUND: Spinal endoscopy has been widely applied in lumbar discectomy and decompression. However, endoscopic lumbar interbody fusion still remains a technical challenge due to the limited space within the working trocar for cage implantation. The purpose of this study was to investigate the feasibility and effectiveness of using a narrow-surface fusion cage in full endoscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for the treatment of lumbar degenerative disease. MATERIALS AND METHODS: From Jun 2013 to Dec 2014, a total of 42 patients (23 males, 19 females) underwent full endoscopic MIS-TLIF at our hospital was recruited. An 8-mm-wide narrow-surface fusion cage was selected for all cases. Perioperative parameters and complications were recorded. Comparisons on visual analog scale (VAS) and oswestry disability index (ODI) scores before and after surgery were performed. At the last follow-up, Nakai grading system was applied to assess patients' satisfaction; meanwhile, interbody fusion was evaluated by computed tomography. RESULTS: Mean operation time was 233.1 ± 69.5 min, and mean blood loss during surgery was 221.8 ± 98.5 ml. Two patients (4.8%) developed neurological complications. Postoperative follow-up ranged from 24 to 36 months (mean 27.6 ± 3.8 months). VAS and ODI scores were significantly improved 3 months after surgery and at the final follow-up, respectively (P < 0.05). Outcome of surgery was graded as excellent for 32 patients, good for 8 patients, and acceptable for 2 patients, corresponding to a success rate ("good" and "excellent") of 95.2%. Thirty-nine of the 42 patients demonstrated solid interbody fusion at the last follow-up, indicating a fusion rate of 92.9%. CONCLUSION: Application of a narrow-surface fusion cage in full endoscopic MIS-TLIF for the treatment of lumbar degenerative disease is feasible and effective. The clinical outcome and fusion success of this procedure were acceptable and promising.

Large enchondroma of the thoracic spine: a rare case report and review of the literature.

BACKGROUND: Enchondroma, a subtype of chondroma, originates from the medullary cavity of the bone and produces an expansile growth pattern. Enchondroma located in the spine is rare and a few cases of large thoracic enchondroma have been reported. The authors document a rare case of large enchondroma in the thoracic spine of a 49-year-old woman, and discuss its clinical, radiological and histopathological characteristics. CASE PRESENTATION: The patient presented with rapidly progressive and severe pain on her upper back. Magnetic resonance imaging revealed an expansile lesion at the posterior elements of T3 that was hypointense on T1-weighted images and mixed iso- to hyperintense on T2-weighted images. Administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) resulted in heterogeneous enhancement. During surgery, a large tumor of 4.2cm × 4.7cm × 2.1cm was resected along with the lamina and spinous process. Histological examination revealed that the tumor consisted of mature hyaline cartilage with typical chondrocytes, indicating that it was an enchondroma. CONCLUSIONS: Despite its benign-growing nature, enchondroma should be examined closely for signs of enchondromatosis and enchondrosarcoma. Complete surgical resection is the treatment of choice for immediate relief of symptoms and avoidance of recurrence.

A minimally invasive posterior lumbar interbody fusion using percutaneous long arm pedicle screw system for degenerative lumbar disease.

The aim of this study is to evaluate the therapeutic efficacy of patients with lumbar degeneration and instability treated with percutaneous pedicle screw fixation and minimally invasive lumbar interbody fusion. Twenty-one patients were selected in our hospital from November, 2012 to March, 2013. The patients with an average age 55.62 years, including 8 vertebral spondylolisthesis, 4 lumbar intervertebral disc herniation, and 9 lumbar spinal canal stenosis cases. All the patients were managed to take the lumbar MRI and radiographs. The comparison of preoperative and postoperative (3 days, 2 weeks, 3 months) VAS and ODI score were analyzed. The results indicated that VAS scores were 7.14 ± 0.79 before operation, and 5.19 ± 0.81 in 3 days after operation, 4 ± 0.84 after 2 weeks, and 2.67 ± 0.66 after 3 months. The pain was relieved, and the postoperative VAS score was lower than that before treatment (P < 0.05). ODI score was 55.8 ± 11.4 before operation, 47.38 ± 9.38 after 3 days, 41.38 ± 8.09 after 2 weeks, 35.76 ± 4.50 after 3 months. ODI score was obviously decreased (P < 0.05). In conclusion, percutaneous pedicle screw fixation combined with minimally invasive interbody fusion is a safe, effective, feasible minimally invasive spine operation, with worthy for spreading.

Three-dimensional visualization of the cutaneous angiosome using angiography.

The purpose of this study was to establish the three-dimensional (3D) architecture of the cutaneous angiosome for assessment and design of the perforator flaps. Two fresh cadavers were injected with carboxymethyl cellulose (CMC)/lead oxide and computed tomography (CT) scanned before and after the injection. The various parts of the cutaneous and subcutaneous tissue derived from one of the injected cadavers were also CT scanned. Three-dimensional reconstruction of the cutaneous angiosome and the two flap designs were performed using Materialise's Interactive Medical Image Control System (MIMICS). Both the reconstructed cutaneous angiosomes and the digital flaps can be displayed independently or in conjunction with bones, source arteries, and skin. The 3D architecture of the cutaneous angiosome ensures clear display of the spatial location, distribution range, and anastomoses relationship of the cutaneous perforators. In addition, the caliber, length, and position of a particular source artery are illustrated in the exact spatial location. As a result, the technique provides visualization of the general area and the expandable direction of a respective flap. This technique has the potential to play an important role in assessing perforator blood supply territory and in the design of new flaps.

Changes of contact pressure and area in patellofemoral joint after different meniscectomies.

PURPOSE: We investigated the contact pressure and area of the patellofemoral joint both before and after different meniscectomies to provide a biomechanical basis for selecting meniscectomy and its clinical application for meniscus injuries. METHODS: Six fresh cadaveric knees were used in the study. Using Staubli robots and an ultra-low-min-type pressure-sensitive tablet, changes in contact area and stress in the patellofemoral joint were measured at various flexion angles following different parts and degrees of meniscectomy. RESULTS: The patellofemoral contact area enlarged with the increase of knee flexion angle. From the values obtained from contact areas and average contact pressure of the patellofemoral joint, we found no significant difference between partial meniscectomy and intact knees, but a significant difference was found between total meniscectomy and intact knees. The contact area after lateral meniscectomy was statistically less than that of intact knees. The mean patellofemoral contact pressure after lateral meniscectomy was larger than in intact knees at each angle of flexion. No significant difference in contact area was observed between intact knees and medial meniscectomy. The average patellofemoral contact pressure after medial meniscectomy was larger than in intact knees from 0° ~ 30° of knee flexion, and no significant differences were found between intact knees and medial meniscectomy while knee bending from 60° to 90°. CONCLUSIONS: Different meniscectomies result in high contact pressure or disordered distribution of contact pressure, which may be the cause of postoperative patellofemoral degenerative arthrosis.

[Modification of a percutaneous transpedical interbody bone grafting apparatus and its application in cadaveric operation].

OBJECTIVE: To modify a percutaneous transpedical interbody bone grafting apparatus for better surgical performance in transpedical interbody bone grafting. METHODS: The puncture needle, guide pin and expander were removed from the original design of interbody bone grafting apparatus, with also modification of the bone grafting funnel, obturator, wick and bone harvesting device. Percutaneous puncture and transpedical interbody bone grafting were performed using the modified apparatus on two cadavers, and the operative procedures, bone grafting scope and surgical trauma were observed. RESULTS: This modified apparatus allowed increased bone grafting scope with shortened operative time, simplified operation procedures, and reduced surgical trauma. CONCLUSION: Percutaneous puncture and transpedical interbody bone grafting can be easily and safely performed with the modified apparatus.

Three-dimensional visualization of pelvic vascularity.

The aim of this study was to establish a 3D digitized model of pelvic vasculature for anatomic study, preoperative planning, and virtual reality. Three adult fresh cadavers were perfused with carboxymethyl cellulose/lead oxide mixture to mark blood vessels, and subjected to multilayer spiral computed tomography scanning to obtain a series of thin sections. Then, the 2D images of the pelvis and pelvic blood vessels were transformed into 3D digitized models using Mimics 11.0. The 2D images of carboxymethyl cellulose/lead oxide filled arteries had the features of entire outline and few constructed defects. The 3D digitized models of the pelvis and pelvic artery system displayed spatial location and the adjacent relationship of arteries with the pelvis. Not only the well-known arteries but also the tiny blood vessels in the reconstructed structures were well demonstrated and observed interactively. The reconstructed tissue flaps, including a lobulated skin flap with the pedicle of superficial epigastric artery, and an iliac flap with the pedicle of deep iliac circumflex artery, demonstrated their blood supply area. This indicated that the modified technique of vascular perfusion with carboxymethyl cellulose/lead oxide and reconstitution with Mimics 11.0 software contributed to 3D digitized model of pelvic vasculature.

[Surgery simulation with a percutaneous and transpedical interbody bone grafting apparatus].

OBJECTIVE: To develop a percutaneous and transpedical interbody bone grafting apparatus for vertebral bone defect reconstruction in thoracolumbar fracture correction via minimally invasive operation. METHODS: The percutaneous and transpedical interbody bone grafting apparatus was designed with CAD software, and the reduction effect, range of bone grafting and surgical complications of the apparatus were investigated in adult cadaveric thoracolumbar body and with computerized surgical simulation. RESULTS: The self-designed apparatus was convenient for percutaneous and transpedical interbody bone grafting that did not give rise to complications. CT showed large bone grafting area with increased density in the vertebral body corrected with this apparatus. CONCLUSION: The designed apparatus allows easy manipulation and efficient bone grafting and repositioning. Minimally invasive interbody bone grafting in thoracolumbar fracture can be easily performed with proper application of the apparatus.