Objective To explore the outcome of acetabular fractures operative treatment. Methods 62 patients with acetabular fractures were enrolled in this study. According to classification of Letournel, fracture of posterior wall 13 cases, fracture of posterior column 9 cases, fracture of anterior column 5 cases, transverse fracture 4 cases, transverse fracture with fracture of posterior wall 6 cases, double column fracture 10 cases, fracture of posterior wall and posterior column 8 cases, fracture of T type 7 cases. Results 62 patients were followed-up for more than one year after operation. All cases had bone union without complications of the infection and sciatic nerve injury. Traumatic arthritis occurred in 2 cases, and the function of the hip-joint was limited in 3 cases. Conclusion Operative reduction and internal fixation can notably increase forward outcome of acetabular fractures.

Objective To introduce the method of C2,3 pedicle screw fixation for management of unstable Hangman fractures and evaluate the clinical effects.Methods From October 2001 to October 2005,26 cases with unstable Hangman fractures were treated using Axis and Vertex pedicle screw system.According to the classification system designed by Levine depending on the radiological manifestations of Hangman fractures,there were unstable fractures in 26 cases,who were subdivided into type Ⅱ in 11 cases,type ⅡA in 10 cases and type Ⅲ in 5 cases.There were 18 males and 8 females,aging from 21 to 56 years with an average of 38.5 years.According to Frankel scale,graded as spinal injury D in 6 cases and E in 20 cases.Points of entry for C2 screw insertion were located at the entrance at the posterior aspect of lateral mass.The drill bit was parallel to both of the medial and superior border of C2 pars interarticularis(usually 15?-25? cephalad to the transverse plane and 20?-25? medial to the sagittal plane).The screw hole in the posterior cortex was overdrilled.3.5-4.0 mm screws(26-30 mm,determined by depth gauge)were drived in after the cortex being tapped.The points of screw penetration for the C3 pedicles was slightly lateral to the center of the articular mass and close to the inferior margin of the inferior articular process of the cranially adjacent vertebra.The insertion angle of the pedicle screw was 35?-45? medial to the midline in the transverse plane.3.5-4.0 mm screws,determined by depth gauge were drived in after the cortex being tapped.The whole procedure was done under monitoring of "C"-arm fluoroscopy for safety and accuracy.Results All patients were followed up from 6 to 54 months,with the average of 29 months.There were no screw loosing and breakage,and no spinal cord and vertebral artery injury after surgery.3 screws were placed too close to the vertebral artery canal in C2 and 7 screws in C3,but without clinical consequences.There were 16 cases in excellent,7 good,3 fair according to Mayo(McGrory)scores.Conclusion C2,3 pedicle screw fixation is a effected method for management of unstable Hangman fractures,which proved its value as a method achieving solid bony fusion combined with low rate of complications.

Objective To evaluate the clinical effectiveness of the combined use of S1 pedicle screws and the iliac screws in treatment of sacroiliac dislocation and fracture. Methods 11 patients with sacroiliac dislocation and fracture were treated with S1 pedicle screw and iliac screw fixation technique. In this group, the dislocation was associated with vertical displacement of the sacroiliac joint and rotational deformity of the pelvic ring. They were classified as type B or type C pelvic disruption according to the Tile's classification. 7 patients with disruption of the symphysis pubis or pubic branch fracture underwent additional fixation of the pelvic ring using a reconstruction plate. The remaining 4 patients were treated by the posterior procedure alone. Results The vertical displacement was completely reduced in 7 patients, and the rotational deformity completely corrected in 4 patients. The reduction was maintained at the time of final follow up evaluation. No perioperative complications were found. The combined use of S1 pedicle screws and the iliac screws provided immediate stability and sufficient reduction for sacroiliac dislocation in the 11 patients in this study. Conclusion This hybrid internal fixation procedure is useful for reduction and fixation of sacroiliac dislocation associated with the vertical and rotational instability of the pelvic ring.

Objective To assess clinical curative effect of three types of combined posterior atlantoaxial internal fixation techniques in treatment of atlantoaxial instability. Methods The study involved 68 patients with atlantoaxial instability treated with different fixation techniques from August 2002 to March 2008. ( 1 ) Transpedicular fixation was performed in 32 patients including 20 patients with Anderson Ⅱ odontoid fractures (seven with old odontoid fracture and 13 with fresh fractures), six with type Anderson Ⅲ fresh odontoid fractures, four with disrupt of transverse ligament of the atlas and two with congenital loose odontoid process combined with atlantoaxial instability. (2) Transpedicular internal fixation with screws of atlas incorporating C2 laminar screws was performed in 20 patients with upper cervical injury including eight with type Ⅱ odontoid process fractures combined with atlantoaxial backward dislocation,four with type Ⅱ odontoid process fractures combined with atlantoaxial forward dislocation, two with nonunion of odontoid process fractures, three with type Ⅲ odontoid process fractures combined with atlantoaxial unsteadiness and three with atlantoaxial dislocation combined with disrupt of transverse ligament of atlas. (3)A total of 16 patients with traumatic atlantoaxial instability, reducible atlantoaxial dislocation and irreducible atlantoaxial dislocation were treated with four-point internal fixation technique using autologous iliac bone grafts. Results (1) A total of 120 screws were implanted in 32 patients, with no spinal cord or vertebral artery injury after surgery. Atlas lateral mass fixation was adopted in three patients because of broken posterior arch of the atlas. Postoperative CT showed that two screws were inserted into the vertebral artery hole and that one screw was inserted medially into the spinal canal and caused medial correx rupture, but both with no clinical symptoms. All 32 patients were followed up for 6-42 months ( average 26 months), which showed solid fusion in all patients. The postoperative JOA scores ranged from 13.2 points to 16.8 points (average 14. 8 points). (2) Thirty-two screws were implanted in 20 patients,with no spinal cord or vertebral artery injury. The patients were followed up for mean six months ( range 6-14 months). Postoperative X-ray showed sound bone fusion, with no cervical instability, loosening or breakage of the screws. (3) The symptoms of all the patients were improved at different degrees, with no neurological deterioration or severe complications, such as nerve blood vessel injury. All 16 patients were followed up for 8-26 months ( average 16 months), which showed bony fusion in all patients at 3-6 months after surgery. The spinal cord function was improved markedly in five patients, good in eight, mild in two but unchanged in one. Conclusions Three types of combined posterior atlantoaxial internal fixation techniques have advantages of rigid, short-segmental and three-dimensional fixation and hence are effective methods for treatment of upper cervical injuries. The combination mode can be varied according to specific condition of the patients.

BACKGROUND: Most patients with posterior pelvic and sacroiliac metastasis are terminally ill. Their treatment is usually palliative and directed toward relieving pain and improving the quality of life with the least possible intervention.OBJECTIVE: To investigate the possibility of percutaneous CT-guided fixation of sacroiliac joint with cannulated lag screw treatment for pathologic pain of sacroiliac joint.DESIGN: Preoperative and postoperative auto-control clinical trial was conducted.SETTING and PARTICIPANTS: The study was completed in Ningbo Sixth Hospital. Eight patients(4 males and 4 females, aged 12 years to 83 years)with metastatic tumor of sacroiliac joint were selected for our study.METHODS: After treatment with percutaneous CT-guided fixation of sacroiliac joint with cannulated lag screw, the sacroiliac joint of the 8 patients became pathologically unstable. Enneking pain scale was obtained preoperatively and postoperatively.MAIN OUTCOME MEASURES: Pain recovery was assessed preoperatively and postoperatively.RESULTS: After 2. 5 years' follow-up, pain of the patients was relieved with a range of 0 to 5(mean 3.2).CONCLUSION: Percutaneous cannulated lag screws with CT guidance help alleviate the patients' pain due to pathologically unstable sacroiliac joint.

Objective To explore the feasibility and application value of combined C2 laminar screw fixation technique in treatment of cervical vertebral injury. Methods Dense axial CT scanning was done on C2 laminar of 32 specimens of cervical vertebra to measure the length and height of the axis, the thickness of upper, middle and lower parts of the axis as well as the angle between the axial ray and the sagittal plane. There were eight patients with cervical vertebral injury including two with type Ⅱ odon-told process fractures combined with backward dislocation of atlanto-axial joint, one with forward disloca-tion of atlanto-axial joint, one with nonunion of odontoid process fractures, two with type Ⅲ odontoid process fractures combined with atlanto-axial joint instability and transverse ligament rupture, one with type Ⅱ Hangman fracture combined with instability of C2～3 and one with forward dislocation of atlanto-axial joint combined with transverse ligament rupture. With accomplishment of traction reduction, combined fixation with axis laminar screws and posterior autogenous lilac graft fusion were done based on injury se-verity of the patients. Results The length and height of axis laminar was (26.2±1.2) mm and (12.8±1.6) mm, respectively. The thickness of upper, middle and lower parts of the C2 laminar was (3.0±1.4) mm, (6.0±1.6) mm and (5.6±1.2) mm, respectively. The mean angle between the axial ray and sagittal plane was 43.5°. All patients were followed up for 6-14 months ( mean 6 months), which showed that all patients obtained favourable bone union and all screws remained at sound position, without deflexion of the screws or any perioperative or postoperative complications. No screw loosening or breakage occurred. Conclusions C2 laminar screw fixation technique can prevent the risk of vertebral artery injury during screw insertion. In the meantime, such technique is simple to operate and free from limitation of the vertebral artery in the cervical foramen. Whole course of visualization during C2 laminar screw insertion may facilitate it as a supplementary method for conventional posterior C2 screw fixation.

Objective To evaluate the clinical effect and safety of the occiput-cervicle or C1-C2 internal fixation and bone graft fusion in treatment of the unstable atlas fracture.Methods A retrospective study was performed in 38 patients with unstable atlas fractures treated by the occiput-cervicle or C1-C2 internal fixation and bone graft fusion from October 2004 to March 2009.Six patients with comminuted atlas fracture combined with instability of the occipito-atlantoid articulations were treated with occiput-C2 fusion(five patients)and with occiput-C3 fusion(one patient).There were seven patients with typical Jefferson fractures,three with semiring fractures,eight with atlas fractures combined with Anderson type Ⅱ odontoid process fractures,three with atlas fractures combined with Hangman's fractures (two patients with Levine and Edwards type Ⅲ Hangman's fractures were treated with occiput-C3 fusion and one patient Levine and Edwards type Ⅱ Hangman's fracture was treated with C1-C2 fusion),three with atlas fracture combined with lower cervicle injury,six with rupture of transverse ligament combined with instability of atlanto-axial joint(Dickman transverse ligament type Ⅰ injury)and two with comminuted fracture of the lateral mass associated with bony avulsion of the medial tubercle and transverse ligament(Dickman transverse ligament type Ⅱ injury).Of all,five patients were treated with occiput-C2 fusion,three treated with occiput-C3 fusion and 30 treated with C1-C2 fusion.Results All the patients were followed up for a range of 12-46 months(average 28 months),which showed improvement of clinical symptoms in some extent postoperatively.The operation time ranged from 80 to 190 min ates(average 135 minates),with intraoperative blood loss for 200-3 300 ml(average 460 ml)and average fluoroscopic time for 60 seconds.There were no neurological deficits,vertebral artery related complications or other complications in all the patients during the surgical operation.No neurological deficit was aggravated after the patient's mobilization with brace three days after operation.The enous plexus of blood vessel at C1-C2 rupture induced by the use of electrocautery was found in three patients who showed no cerebral hemodynamic deficit after hemostasis with hemostatic sponge and cotton piece.The follow-up X-ray and CT manifested osseous fusion in all the patients,with no looseness or breakage of the screws.The late follow-up showed pain associated with movement and limited range of motion in four patients(11%)and occipital neuralgia in one.Conclusions An occiput-cervicle fixation fusion or a C1-C2 fixation fusion combined with short external fixation can reestablish the upper cervical stability and prevent further injury of the spinal cord and nerve function and hence is an ideal option for C1 burst fracture with or without rupture of the transverse ligament.

Objective To discuss the anatomical and radiographic parameters of medullary screw fixation of anterior acetabular column so as to provide reference for clinical application. Methods Thirty cadaveric pelvic specimens (including 18 males and 12 females) were involved in the study and fixated re-spectively with 30 retrograde medullary cannular lag screws through pubic tubercle to acetabular posterosu-perior on the left side and with 30 anterograde medullary cannular lag screws through acetabular posterosu-perior to pubic tubercle on the right side. Then, two-dimensional multiplanar CT reconstruction was done to measure the angle and length of the anterograde and retrograde medullary screw trajectory, the relationship of screws with acetabular bone and penis and determine optimal point and angle of screw insertion. Re-suits The entrance of the retrograde medullary screw was located at pubic tubercle, with vertical dimen-sion of ( 17.15±1.82) mm to pubic symphysis and that of (20.51±2.19) mm to superior margin of pu-bis. For the anterograde medullary screw, the distance from the entrance of the screw to greater sciatic notch was (33.25±2.35) mm, with safe insertion angle of (32.1±2.7)°of cephalon tilting at the sagittal plane and (46.5±3.6)°of lateral tilting at the coronal plane. The entrance angle of the anterugrade and retrograde medullary screw trajectory was similar, with only opposite direction and minor difference between the left and the right sides (P>0.05). The length of medullary screw trajectory was (119.5±2.2) mm, with insignificant difference between both sides ( P >0.05). The maximum diameter of the screw was 7.2 mm. Conclusions Medullary screw fixation of anterior acetabular column is clinically feasible but needs rather high accuracy and can be used as an alternative to plate fixation.

ObjectiveTo investigate application of the anterior cervical pedicle screw in the lower cervical spine.MethodsTwenty disarticulated human vertebrae(C3-C7) were evaluated with computed tomography for pedicle morphometry Parameters included vertebral body height,vertebral body depth,vertebral body width,outer pedicle width,outer pedicle height,pedicle axis length,transverse section angle,sagittal section angle,transverse intersection point distance and sagittal intersection point distance.On the basis of these data,the screw channel was determined and the screws were inserted in the specimen.Five patients underwent surgical reconstruction using anterior pedicle screw fixation.After surgery,physical examination and roentgenograms and CT scans were performed in all patients.ResultsThe transverse section angle increased from C3(45.7°±4.0°) to C5(52.1°±5.9° ),but decreased from C6(47.8°±6.7°) to C7(44.4°± 8.3°).The sagittal section angle gradually increased from C3 (93.4°±7.2°) to C6( 112.1°±6.2°) but decreased a little to C7(102.7°±8.5°).The distances in transverse section was about 1.97-3.98 mm and in sagittal section was 3.4-7.5 mm.Anterior pedicle screws were inserted successfully in all specimens without critical pedicle wall perforations.Patients were permitted to ambulate the next day after surgery with a cervical collar.Postoperative neurological improvement was observed in all cases.Postoperative radiographic evaluation confirmed proper insertion of anterior pedicle screws without pedicle perforaton.The average follow-up time was 10.6 months.No anterior pedicle screw breakage and loosening was observed.ConclusionThe entry point in anterior pedicle screw should located in 5mm to upper endplate and near anterior median line.The transverse section angle should be 45.7°-52.1°and the sagittal section angle should be 93.4°-112.1°.The lengths of the screw should be about 32 mm.

Objective To investigate the prevention and management strategies of in-hospital complications in the hip replacement in elderly patients(≥80 years old) Methods The data of 42elderly patients with hip replacement between Oct.2004 and Dec.2006 were collected and analyzed.Their age ranged from 80 to 96 years with an average of 84.6 years.Twenty-four cases were associated with severe osteoporosis(Dorr Ⅲ),13 with coronary heard disease,10 with arrhythmia,7with diabetes,5 with cerebral paralysis.Twenty five cases had a cemented stem bipolar femoral head replacement,2 had uncemented stem bipolar femoral head replacement,7 had cemented total hip replacement,3 had revision of total hip replacement. Results No death occurred during operations,1 died postoperatively due to dislocation at the 5th day postoperation.One case had coma for 1 week after general anaesthesia.5 had temporary cognitive handicap,38(90.5%)were able to walk at the aid of walker with easement of pain before discharging. Conclusions To gain good results in elderly patients with hip arthroplasty,less invasive and quick anaesthetic technique and operative procedures are encouraged.Meticulous preoperative preparation.active preventing and treating the intraoperative and postoperative complications should be emphasized.