Objective To investigate the classification of atlas pedicles and the methods of the pedicle screw fixation. Methods To study the classification of atlas pedicles, 48 dry adult atlas specimens were measured. By atlas 3D-CT reconstruction, two transverse sections were establ ished by going through the one third of the lateral atlas pedicle and 2 mmbelow the vertebral artery sulcus. By setting 3.50 mm and 1.75 mm as the standardized diameter and radius for the screwand according to the thickness of bone substance of vertebral artery sulcus that went through the one third of the lateralatlas pedicle, the anatomical morphology of atlas pedicles were classified into three types: general type with 40 specimens (83%), l ight variation type with 6 specimens (13%), and severe variation type with 2 specimens (4%). The entry pathway was confirmed by the intersection l ine of the two transverse sections that went through the lateral one third of the atlas pedicle and 2 mm below the vertebral artery sulcus. The project-point of the entry pathway on the atlas posterior arch was considered to be the entry point. Forty-eight dry atlas specimens were used to measure the following relevant anatomic data with an electronic cal iper: the distance between the entry point and the posterior margin of the lateral mass (L1), the height of atlas pedicle at the entry point (L2), the vertical distance between the entry point and the inferior articular facet of the lateral mass (L3), the mass height at the entry point (L4), the mass width at the entry point (L5), the width of the atlas pedicle at the entry point (L6), the thickness of the pedicle under the vertebral artery sulcus at the entry pathway (H1). To research the method of the pedicle screw fixation, 12 fresh-frozen adult atlas specimens were adopted to simulate the fixation of the pedicle screw. The thickness of the bone substance of vertebral artery sulcus on both the left and the right sides of the pathway was grinded into 3 types: 1.5 mm and 2.5 mm, 1.5 mm and 4.0 mm, 2.5 mm and 4.0 mm, and each type had four specimens. The entry pathway was confirmed by the intersection l ine of two transverse sections that went through the lateral one third of atlas pedicle and 2 mm below the vertebral artery sulcus. Results On the left side, L1 was (5.79 ± 1.24) mm, L2 (4.55 ± 1.29) mm, L3 (5.12 ± 1.06) mm, L4 (12.43 ± 1.01) mm, L5 (12.66 ± 1.37) mm, L6 (7.86 ± 0.77) mm, and H1 (4.11 ± 1.25) mm. On the right side, L1 was (5.81 ± 1.26) mm, L2 (4.49 ± 1.22) mm, L3 (5.15 ± 1.05) mm, L4 (12.49 ± 0.98) mm, L5 (12.65 ± 1.38) mm, L6 (7.84 ± 0.78) mm, and H1 (4.13 ± 1.29) mm. There was no significant difference between the two sides (P gt; 0.05). After simulation of inserting screws, no screw in the specimens was found to break the bone substance in the sulcus of vertebral artery. Conclusion For the pedicle screw fixation of those patients whose atlas posterior arches are not high enough, we might partly drill through or beyond the atlas posterior arch. The entry point should be ascertained by preoperative 3D-CT reconstruction and intra-operative exploration.
Objective To introduce the recent advances of the application of computer technology in tissue engineering. Methods The recent original articlesrelated to computer technology, medical image technology, computer-aided design, the advanced manufacture technology were summarized and systematically analyzed.Results Computer-aided tissue engineering is a new fieldon tissue engineering. It is the future direction of tissue engineering study. This article reviews recent development of medical CT/MRI scanning, three-dimensional reconstruction, anatomical modeling, computeraided design, computer-aided manufacturing, rapid prototyping， RP manufacturing of tissue engineering scaffolds and computeraided implantation.Conclusion Computer-aided tissue engineering can be used in scaffolds design and fabrication, computer-aided artificial tissue implantation. It is a new field on tissue engineering.
ObjectiveTo explore the long-term effectiveness of expandable Cage in treatment of degenerative lumbar disease. MethodsBetween January 2005 and January 2008, 72 patients with degenerative lumbar disease were treated by expandable Cage and followed up for 5 years. Of 72 cases, 41 were male and 31 were female with an average age of 40.5 years (mean, 35-65 years), including 35 cases of lumbar spinal stenosis, 20 cases of degenerative lumbar instability, and 17 cases of serious lumbar intervertebral disc protrusion combined with lumbar instability. The disease duration was 6-28 months (mean, 9 months). The affected lumbar segments were L3, 4 in 6 patients, L4, 5 in 37 patients, and L5, S1 in 29 patients. The Oswestry disability index (ODI) was used to evaluate the effectiveness before and after operation and to calculate the improvement rate. During the follow-up, the anteroposterior, lateral, and dynamic X-ray films were taken to evaluate the operated segment fusion rate. The intervertebral lordosis angle was measured, and adjacent segment degeneration was observed. ResultsThe operation time was 35-90 minutes (mean, 65 minutes); the intraoperative blood loss was 200-450 mL (mean, 280 mL), and all the patients received intraoperative autologous blood transfusion; the postoperative bedridden time was 3-7 days (mean, 4.5 days); the hospitalization days were 10-18 days (mean, 12 days). No complications of nerve root injury, cauda equina injury, or cerebrospinal fluid leakage occurred during operation. All patients achieved primary healing of the incisions. All 72 patients were followed up for 5 years. At 3 months, 1 year, and 5 years after operation, the ODI were 8.2±2.6, 6.9±1.9, and 6.4±1.3 respectively, showing significant differences when compared with preoperative value (41.5±3.5) (P<0.05); the improvement rates were 87.3%±1.2%, 90.1%±0.8%, and 91.6%±1.3% respectively, showing no significant difference (F=0.492, P=0.375); the intervertebral lordosis angles were (5.1±1.2), (5.0±0.5), and (5.4±0.8)°respectively, showing no significant difference (F=0.570, P=0.453). At 5 years after operation, the intervertebral fusion rate was 100%, with no adjacent segment degeneration. ConclusionUsing expandable Cage to treat degenerative lumbar disease can get stabilization without pedicle screw fixation, the good effectiveness is shown after long-term follow-up.
To research the operative method and the cl inical efficacy of repairing and reconstructing tendon and l igament with allograft tendon. Methods From September 2000 to May 2007, 164 cases with tendon and l igament injuries were treated, including 116 males and 48 females aged 21-47 years old (average 31.5 years old). There were 126 cases of anterior cruciate l igament injury, 18 cases of complete acromioclavicular dislocation, 10 cases of old dislocation of radialhead, 4 cases of Achilles tendon rupture, 2 cases of tibial is anterior muscle rupture, 2 cases of patellar tendon rupture, and 2 cases of rectus femoris rupture. Time interval between injury and hospital admission was 4-345 days (average 75 days). Allograft tendon 10-26 cm in length with suture anchor or absorbable interference screw was used to reconstruct the l igament and tendon. Results All wounds healed by first intention, except one case of rectus femoris rupture. All patients were followed for 10-36 months (average 21 months). The international knee documentation commitee and the Lysholm score of patients with anterior cruciate l igament injury 12 months after operation were significantly higher than that of before operation (P lt; 0.01). According to the Lazzcano and Karlsson score standard, 13 cases of complete acromioclavicular dislocation at 10-12 months after operation were graded as excellent and 5 cases were good. According to Arner Lindholm score standard, 3 cases of Achilles tendon rupture at 8-16 months after operation were graded as excellent and 1 case was good. For the patients with tibial is anterior muscle rupture, at 10-17 months after operation, the limitation of dorsal extension in ankle joint was 5°, and the muscle strength in the anterior tibial is muscle was decreased. For the patients with patellar tendon rupture, one completely restored the motion range of the knee joint 14 months after operation, the other had knee extension l imitation of 10° at 13 months after operation. For the patients with rectus femoris rupture, one had 15° of extension limitation at 18 months after operation, the other suffered limitation of both extension and genuflex at 12 months after operation. According to the Broberg-Morrey score standard, 7 caseswith old dislocation of radial head were graded as excellent and 3 cases were good at 3-36 months after operation. Conclusion Allograft tendon is a good material for repairing and reconstructing tendon and ligament injuries, but attention should be paid to postoperatively early exercise under appropriate protection and early management of local rejection.
ObjectiveTo study the changes of bacterial flora after a series of preoperative oral disinfection and the postoperative recovery of patients with craniovertebral junction disorders who were treated with transoral approach operations. And to provide a theoretical basis for the prevention of postoperative complications such as infection.MethodsThe clinical data of 20 cases with craniovertebral junction disorders and treated with transoral approach operations between October 2009 and May 2010 were analyzed. There were 8 males and 12 females, aged 2-66 years (median, 34.5 years). According to the classification of American Spinal Injury Association (ASIA), there were 4 cases of grade B, 8 of grade C, 6 of grade D, and 2 of grade E. The Japanese Orthopedic Association (JOA) score was 10.3±3.0. The mucosa samples of the posterior pharyngeal wall were sent for bacteria culture. These samples were collected by sterile cotton swabs at four crucial points including 3 days before operation/before gargling (T1), 3 days after continuous gargling by chlorhexidine acetate/after anesthesia intubation on the day of operation (T2), after intraoperative cleaning and washing of the mouth (T3), and after intraoperative iodophor immersion for 5-10 minutes (T4). The microflora was stained by means of smear and further counted after an investigation by microscope. The ASIA classification and the JOA scores were applied to evaluate the postoperative nerve function of the patients. A regular reexamination of cervical vertebra with X-ray film, CT, and MRI was conducted after operation to evaluate the reduction of atlantoaxial dislocation, internal fixation position, bone graft fusion, inflammatory lesion, and tumor resection in the craniovertebral junction.ResultsAfter a series of oral disinfection, the mucosa of the posterior pharyngeal wall of all the patients was in a sterile state, which was considered as type Ⅰ incision. All these 20 patients were treated with successful operations, without any intraoperative injury in vertebral artery and spinal cord, or any postoperative complications such as plate loosening, incision infection, or intracranial infection. All the patients were followed up 3-23 months, with an average of 5.15 months. The symptoms such as neck pain, limb numbness and weakness, neural symptoms, etc. were improved to different degrees after operation. The JOA score was improved to 13.4±1.9 at 3 months after operation, showing significant difference when compared with preoperative score (t=8.677, P=0.000); and the atlantoaxial joints had been fused. At last follow-up, the ASIA grades were improved when compared with those before operation. ConclusionIt is safe and effective to cut the posterior pharyngeal muscle layer and implant internal fixation by means of transoral approach in the treatment of craniovertebral junction disorders.
Objective Supracondylar closing wedge osteotomy is a standard operation for the management of post-traumatic cubitus varus deformity. There are many fixation methods for the broken ends of bone. However, most of these fixation methods are fraught with various complications. To evaluate the methods and functional results of double volume internal fixation for correction of adult post-traumatic cubitus varus deformity. Methods The cl inical data were retrospectively reviewed, from 22 cases of adults post-traumatic cubitus varus deformity between June 2007 and December 2010.There were 16 males and 6 females, aged 18-29 years (mean, 21 years) and they all had a history of supracondylar fracture. The deformities of cubitus varus appeared at 6 months (range, 3 months to 1 year) after fracture, and the operations were carried out at 4-17 years (mean, 8 years) after deformity occurrence. The valgus angle were 16-25° (mean, 20.6°) and the Flynn functional scores were all poor before operation. Supracondylar closing wedge osteotomies were performed. Two reconstruction plates were moulded and placed to the media and lateral volumes of the humerus to fix the broken ends of the osteotomy surfaces. External fixation was not needed and early rehabil itation was performed postoperatively in all cases. Results Incisions healed by first intention. All cases were followed up 6 to 24 months (mean, 13 months). At last follow-up, the valgus angle was 0-10° (mean, 7.5°). All cases got bone union at 8-13 weeks (mean, 10 weeks) after operation. No related complications occurred, such as infection, nervous or vein injury, and loosening or breakage of internal fixator; and no cubitus varus recurred. The Flynn scores were excellent in 17 cases, good in 3 cases, and fair in 2 cases; the excellent and good rate was 91%. Conclusion The operation of supracondylar osteotomy with double plates internal fixation for the correction of adult post-traumatic cubitus varus deformity can rigidly stabil ize distal humerus, which is helpful to functional training just after operation and satisfactory restoration of the elbow function.
ObjectiveTo evaluate the ectopic osteogenesis of recombinant human bone morphogenetic protein 2 (rhBMP-2) loaded chitosan (CS)/dextran sulfate (DS) by micro-CT. MethodsrhBMP-2/CS/DS microspheres were prepared by the ionic crosslinking and its shape was observed under the scanning electron microscope. The release of rhBMP-2 was determined from resultant microspheres by ELISA assay. Forty-eight Sprague Dawley male rats were randomly divided into 4 groups (n=12), quadriceps muscle bag model was made, gelatin sponge (group A), CS/DS microspheres (group B), rhBMP-2 (group C), and CS/DS/rhBMP-2 microspheres (group D) were implanted into the bags respectively. The tissue samples with heterotopic ossification were harvested for micro-CT scanning at 4, 8, 12, and 16 weeks. The tissue mineral density (TMD), bone volume fraction (BVF), trabecular thickness (Tb.Th), trabecular number (Tb.N), bone mineral density (BMD), and tissue mineral content (TMC) were measured. ResultsThe prepared rhBMP-2/CS/DS microspheres with smooth surfaces were spherical and evenly disperses without obvious agglomeration. At 2 hours, microsphere started a sudden release period in vitro; the release reached a peak at 2 days; and the release cycle lasted about 20 days. The rats survived to the end of the experiment. At each time point after operation, no radiation developed and no osteogenesis was observed by three dimensional reconstruction in groups A and B. However, radioactive strength and reconstructed bone tissue gradually increased in groups C and D, and group D had more radioautography and more bone tissues than group C. At each time point, TMD, BVF, Tb.Th, Tb.N, BMD, and TMC of groups A and B were zero. Ectopic bone formed with time, the other parameters showed an increasing trend except Tb.N in groups C and D, showing significant difference when compared with groups A and B at each time point (P < 0.05). There was no significant difference between groups C and D at 4 weeks (P>0.05); the parameters of group D were significantly higher than those of group C at 8-16 weeks (P < 0.05). ConclusionrhBMP-2/CS/DS microspheres have stronger ability of ectopic bone formation than single rhBMP-2.
Objective To evaluate the osteogenic effect of dextran sulfate/recombinant human bone morphogenetic protein 2/chitosan (DS/rhBMP-2/CS) combined with coralline hydroxyapatite (CHA) in repairing large segmental bone defects by radiographic feature. Methods Fifty-seven 24-week-old male New Zealand rabbits were prepared for establishing right radius bone defect model of 20 mm in length. In which 54 rabbits were randomly divided into 3 groups (n=18), and the CHA, DS/rhBMP-2/CS/CHA, and rhBMP-2/CHA artificial bone grafts were implanted into the bone defect in groups A, B, and C respectively; the remaining 3 rabbits were implanted nothing as blank control group. After operation, the gross condition of the animals was observed; at 4, 8, and 12 weeks after operation, X-ray film observation, Micro-CT scanning, and three-dimensional reconstruction were performed to obtain the volume of the new bone. Results The experimental animals recovered well and were in normal condition. X-ray observation showed that the bone healing in group B was better than that in groups A and C at each time point. At each time point after operation, the X-ray scores of group B were significantly higher than that of group A and group C (P<0.05); the scores of group C at 8 and 12 weeks after operation were significantly higher than that of group B (P<0.05). Micro-CT scanning and three-dimensional reconstruction observation showed that at each time point after operation in group A, the bone defect area had less bone formation and poor osteogenesis; in group B, there were many new bone tissues in bone defect area, and the bone remodeling was well, and gradually closed to normal bone morphology at 12 weeks; in group C, there were many new bone tissues in bone defect area, but the bone formation was general. The new bone volume of group B was significantly higher than that of group A and group C (P<0.05) at each time point after operation, and the score of group C was higher than that of group A at 8 weeks after operation (P<0.05). Conclusion The osteogenic effect of DS/rhBMP-2/CS/CHA sustained-release artificial bone is much better than that of single CHA and rhBMP-2/CHA, which can provide a new idea for treating bone defect by using bone tissue engineering in the future.