Objective To study the clinical characteristics of atlanto-axial dislocation and instability caused by different reasons. Methods 388 cases of atlanto-axial dislocation and instability admitted between Jan 1975 and Apr 2000 were reviewed retrospectively. Results 262 cases were caused by anomaly, 71 by trauma and 55 by other reasons. 238/262 had bony deformity, including anomaly of odontoid process, atlanto-occipital assimilation, skull basilar invagination and some others. Simple anomaly of odontoid was the most commonly seen etiology. Myelopathy occurred at similar morbidity among each kind of patients. But patients who presented symptoms for longer time were more likely to have myelopathy. It is difficult to reduce chronic fractures of the odontoid process compared with the fresh fractures. 19 cases with chronic fracture suffered from severe myelopathy. Patients with chronic atlanto-axial fracture over 1 year were more likely to have secondary damage of spinal cord than those within 1 year. Conclusion Atlanto-axial dislocation and instability is more commonly caused by anomaly than trauma. Once the patients with atlanto-axial anomaly present clinical signs, they should be treated as soon as possible. Traumatic atlanto-axial instability should be treated at the early stage to avoid myelopathy.

Objective To investigate the effects of absorbable gelatin sponge, chitosan and sodium hyaluronate(HA) on inhibition of postoperatively epidural scar formation in animal models with posterior discectomy and the concentrations of HA in the cerebral spinal fluid was also determined. Methods 96 Wistar rats older than 12 months were equally allocated into four groups. Each animal underwent a unilateral hemi-laminectomy and discectomy. Absorbable gelatin sponge, chitosan and HA were placed at the sites of surgery in three groups respectively. The fourth group undergone laminectomy and discectomy only, was served as control. At the time of 2,4, 8, 12 weeks postoperatively, 6 rats in each group were sacrificed for gross evaluation, histology and transmission electron microscope studies. The areas of epidural scar and spinal canal were measured by a computer image processor, and were compared statistically. The concentrations of HA in the cerebral spinal fluid in the HA groups and control groups were tested. Results The epidural scar areas in the chitosan and HA groups were significantly less than those in the control and absorbable gelatin sponge groups; no significant difference was found among the spinal canal areas of all the groups at different time phase; the compression and dislocation of the dura and spinal nerve roots and the discontinuity of the annulus fiber were observed in every group and time phase. The two cases with highest concentrations of HA were in the HA group at 2-week. Conclusion Chitosan and HA are able to inhibit the epidural scar formation after posterior discectomy. The healing of the annulus must be considered when evaluating the scar inhibition effects of materials. When the materials are placed in the epidural space, their effects on the central nervous system should be considered.

Objective To describe the methods of treatment of fresh and old fractures of the elbow joint with internal fixation.Methods Ten cases of fracture of the elbow with complete records were reviewed; 9 of them were male and 1 female; 6 of them were Han people and 4 Tibetans. The average age was 31 years. Four cases had open fractures and 6 had closed fractures. Among the cases of open fractures, 3 were treated with routine debridement and internal fixation of the fragments or internal fixation plus advanced skin flaps. One was treated as closed fractures after wound healing. The 6 cases of closed fractures were treated with a single tension band wiring, tension band and screw fixation, or screw fixation. Results The mean duration of the follow up was 8 months. Fracture healing was seen at 3－ 4 months. The range of motion of fresh fractures of the elbow and forearm was  4.2° － 144.2° . The old fracture cases had the range of motion of  31.3° － 115° without restriction in pronation and supination. Conclusion The intra articular fracture of elbow joint must be treated with early surgery to attain anatomical reduction with firm internal fixation. Early functional exercise is also important for the recovery.

Objective To assess the feasibility and clinical results of video-assisted high anterior transcervical approach (Smith-Robinson) in treatment of spinal lesions of the craniovertebral junction. Methods Between April 2007 to October 2009, nineteen consecutive patients with spinal lesions of the craniovertebral junction were included in the study. There were 9 males and 10 females aged from 16 to 62 years old with a mean of 32 years. The primary pathologies included 4 cases with chronic odontiod fracture, 2 cases with purely irreducible atlantoaxial dislocation, 6 cases with os odonteideum, 1 case with Marfan synd rome, 1 case with primary basilar invagination from Kippel-Feil syndrome, 3 case with axis tumor and 1 case with irreducible rheumatoid atlantoaxial dislocation. All of the patients underwent combined video-assisted high anterior transcervical procedure and posterior fixation at one-stage. The anterior procedure included atlantoaxil release and reduction (8 cases), odontoidectomy (8 cases), and intralesional extracapsular excision and reconstruction (3 tumor cases). The posterior technique were C1-C2 pedicle screw fixation (13 cases), C1-C3 pedicle screw fixation (2 cases), and occipitalcervical fusion (4 cases). Results Anatomical reduction was achieved in eight cases with anterior release and reduction. Tumors were completely removed in three cases with axial tumor. The mean follow-up was 14 months (6-36 months). All of them achieved solid bone fusion. In the 14 patients with symptoms of spinal cord dysfunction, the average Japanese Orthopaedic Association (JOA)score had improved from 9.1±3.3 preoperatively to 14.1±2.9 postperatively. The improvement rate was excellent for 7 cases, good for 5 cases, fair for lcase and poor for 1 case. One patient experienced leakage of cerebrospinal fluid which was resolved by bioprotein gelatin blocking and lumbar subarachnoid continuous drainage within 1 week. Dysphagia which occurred in 3 cases responded well to dexamethason and mannitol.No infection and hardware failure were observed. Conclusion Video-assisted high anterior transcervical procedure is a safe and effective alternative for treating spinal lesions in the craniovertebral junction.

Objective To improve the arthroscopic posterior cruciate ligament (PCL) reconstruction using tibial Inlay technique. Methods The special arthroscopic device and related fixation technique were designed. Five cadaveric knees were used to simulate the process of arthroscopic posterior cruciate ligament reconstruction using tibial Inlay technique. The knees were cut open to observe whether the outlet of the tibial tunnel shape and location met the design requirements. Thirty normal MRI films were measured to identify tunnel angle and localizer angle. Results The inner outlet of tunnel was conical shape(14 mm×7 mm×15 mm) and the outer outlet was cylinder-shaped (a diameter of 7 mm). The tibial drill was designed into a split structure and could be assembled in vitro. According to the data obtained from MRI films, the angle between the plane of posterior cruciate ligament and horizontal place was 36°-47°, and the localizer was fixed at 50°.The achilles tendon was used as implant and the allogft bones were designed into conical shape to fit the inner outlet of tunnel. The other end of implant to the proximal tibia was fixed with button plate. All reconstruction operations were performed under arthroscopy. The outcomes of procedure were satisfactory. There were no vascular or peripheral nerve injuries in the cadaveric knees The tunnel position was accurate and the shape of tunnel had met the design requirements. Conclusion Our results imply that improved arthroscopic of posterior cruciate ligament using tibial Inlay technique is simple, accurate, rapid and stable fixation.

Objective To investigate the efficiency and safety of articulating spacer for severe infected knee arthroplasty in patients with medical comorbidities and local sinus tracts. Methods Ten consecutive patients with medical comorbidities (rheumatoid arthritis, diabetes mellitus, etc) or local sinus tracts,who were complicated with late infected TKA, were included in the study. All the patients underwent twostage revision using articulating spacers. All of the patients were debridement thoroughly and followed by implantation of an antibiotic-loaded cement articulated spacer. Two-stage revisions were not followed untill the infection were controlled. The hospital for special surgery (HSS) knee scoring system and range of motion were used to evaluate the outcomes. Results One patient underwent knee fusion because the infection was not controlled after first-stage surgery. The other 9 patients had no evidence of infection. The mean follow-up was 50 months (range, 24-90 months), no recurrent infection developed for these 9 patients. The mean modified HSS score had improved from 48 points (range, 32-63) before the resection surgery to 79 points (range,62-91) at the end of the spacer period. At the latest follow-up, the modified HSS score averaged 89 points (range, 74-95). The good and excellent rate was 0, 80% and 100%, respectively. The average range of motion had increased from 13°-70° preoperatively to 8°-93° prior to the revision. And at the latest follow-up, the range of motion averaged 3° to 110°. Conclusion The delayed two-stage revision using an articulating spacer is effective in the treatment of chronically infected TKA characterized by simple, good reproducible, high rate of infection control, better joint function after surgeries

Objective To compare the clinical outcomes of open reduction and internal fixation (ORIF) with total elbow arthroplasty (TEA) for type C inter-condylar fractures of the distal humerus in the elderly. Methods Twenty-two patients who were treated with ORIF or TEA from April 2003 to September 2009 were included in the study. All fractures were OTA classification 13C. Among them, 10 patients who were treated with ORIF were follow up for 8-56 months, while 12 patients who were treated with TEA were followed up for 15-54 months. The Mayo elbow performance score (MEPS) and the complications were compared. Results Using the MEPS, there were 2 in excellent, 4 in good, 4 in fair in the patients treated with ORIF. Complications included heterotopic ossifications (2 cases) and ulnar nerve dysfunction (2 cases).There were 6 in excellent, 4 in good, 2 in fair in the patients treated with TEA. Complications included 1heterotopic ossification (1 case), ulnar nerve dysfunction (1 case), the weakness of musculus triceps brachii (1 case). The patients treated with TEA had significantly better range of motion (107.5° vs 84.5°, P=0.007),also had better MEPS (87.9 vs 75.5, P=0.047) than those with ORIF had ones. Conclusion TEA is a liable option for type C inter-condylar fractures of the distal humerus in the elderly.

Objective To discuss the operative procedures and clinical result of posteromedial and posterolateral approaches in treatment of posterior condylar tibial plateau fractures. Methods From January 2006 to June 2008, 21 patients of posterior condylar tibial plateau fractures were treated by posteromedial and posterolateral knee approaches. There were 12 males and 9 females. The age ranged from 28 to 68 years, with a mean of 39.5 years. Of the patients, 13 had resulted from a traffic accident and 8 had caused by a fall. As for the state of posterior condylar tibial plateau fractures, 7 patients had a medial condylar.fracture, 8 patients had a lateral condylar fracture and 6 patients had a bilateral condylar fracture. Results A follow-up lasted 12-24 months (mean 16.2 months ) in 21 patients. There was no infection, no varus or valgus of the knee, no nerve injuries and loosening or breakage of the screw. All cases had attained bone union. According to the Rasmussen functional scoring, the results were excellent in 12, good in 7 and fair in 2. The excellent and good rate of clinical results was 90.5%. Radiologic results were graded with the Rasmussen score to evaluate the reduction of fracture. There were excellent in 13, good in 7 and fair in 1. The excellent and good rate of clinical results was 95.2%. Conclusion Posteromedial and posterolateral approaches can facilitate the reduction and fixation for posterior condylar tibial plateau fractures. It has many advantages such as good exposure, less invasion and the excellent clinical results.

Objective To analyze the outcomes of bracing treatment for girls with adolescent idiopathic scoliosis (AIS), and to investigate the predictive factors of the protocol. Methods This study included 142 girls with AIS who finished standardized bracing treatment from July 2003 to July 2009. These patients had a mean age of 13.1±1.5 years, a mean main curve of 29.6°±5.4°, and a mean Risser grade of 2.0±1.5 before bracing treatment. Curve progression was defined that Cobb angle was greater than 6° compared to bracing initiation or was aggravated to more than 45° (indicative for surgery). The outcomes of bracing treatment were assessed based on the ratio of curves of progression or indicative for surgery. Chi-square and Logistic regression Analyses were performed to investigate the predictive factors of bracing treatment. Results The duration of bracing treatment averaged 2.5±1.0 years. Twenty-seven girls with curve progression (19%)and 115 girls (81%) with non-progression were found. Final curve which was greater than 45° was found in 18 girls (13%) who need a correction surgery, the remaining 124 girls (87%) had completed bracing treatment and avoided surgery. Chi-square analyses revealed that curve progression were more common in younger girls with lower Risser grade, with initial larger Cobb angle and with a main thoracic curve pattern.Logistic regression analyses found that premenarchal status and a main thoracic curve pattern were the independent risk factors of curve progression despite bracing. While initial Cobb angle which was greater than 30° was the additional independent risk factor of progression requiring surgery. Conclusion Bracing treatment could effectively prevent curve progression in most girls with AIS. The degree of growth maturity, the pattern and grade of curve are the influencing factor for bracing treatment.

Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin hospital and Tongji hospital were included in the study from January 2010 to August 2010. There were 11 males and 9 females. Each patient was exposed to spiral CT preoperatively. Then these primitive CT dates were imported into digital orthopedics clinical research platform (SuperImage orthopedics edition 1.1, Cybermed Ltd). The volume and maximum diameter of bone tumor were measured before operation by three-dimensional reconstruction technology. The actual tumor volume was measured during the operation. The tumor volume was also calculated from plain X-rays and CT scans as ellipsoidal or cylindrical depending on the tumor configuration and presence or absence of a soft tissue component. Results The tumor volume was measured to be (14.92±7.34) mm3, (16.65±6.95) mm3 and (34.29±15.70) mm3 using three-dimensional reconstruction technology, intraoperative elevation, and traditional radiograph measurement separately. It was found that there was no difference regarding the outcomes of measurement between three-dimensional reconstruction technology and gross intraoperative measurement. But obvious difference was detected between gross intraoperative measurement and traditional radiograph measurement. Coefficient of correlation between diameter and volume of bone tumor was 0.325 (P=0.162). Conclusion Digital measurement is a precise, efficient,convenient and repeatable method for bone tumor measurement.