Objective To explore the treatment and clinical outcomes of unstable combined fractures of pelvis and acetabulum.Methods From January 2013 through December 2014,21 unstable pelvic fractures associated with acetabular fractures received surgical treatment at our department.They were 18 men and 3 women,aged from 21 to 55 years (average,43.2 years).By the Tile classification for pelvic fractures,12 cases were type B and 9 type C.By the Letourel-Judet classification for acetabular fractures,11 cases were transverse fractures,5 both-column fractures,3 posterior column + posterior wall fractures,and 2 anterior column fractures.The intervals between injury and surgery averaged 6.5 days (from 4 to 15 days).Results The 21 cases were followed up for 6 to 18 months (average,9 months).According to the Matta's criteria for pelvic reduction,5 cases were excellent,12 good,and 4 fair,giving an excellent to good rate of 81.0％.According to the Matta's criteria for acetabular reduction,5 cases were excellent,11 good,and 5 poor,giving an excellent to good rate of 76.2％.The pelvic fractures healed after 12 to 18 weeks (average,14.5 weeks);the acetabular fractures healed after 12 to 22 weeks (average,15.5 weeks).According to the Majeed's functional evaluation at the last follow-ups,10 cases were excellent,8 good and 3 fair,giving an excellent to good rate of 85.7％.According to the Merle d'Aubigné-postel evaluation,8 cases were excellent,9 good,and 4 fair,giving an excellent to good rate of 81.0％.Three patients had nerve injury which was almost completely recovered 4 to 6 months after operation.Two cases had wound infection which was controlled after debridement for twice.No other complications like ectopic ossification,avascular necrosis of the femoral head,iatrogenic vascular or nerve lesion was observed during the follow-ups.Conclusion Precise diagnosis,rational plan,careful surgery,effective reduction,rigid fixation and active rehabilitation are keys to fine outcomes in the treatment of unstable pelvic fractures associated with acetabular fractures.

Objective To estimate the anatomic variation of the right inferior phrenic artery(RIPA)with multi-detector tomography(MDCT)scans.Methods 45 patients with hepatocellular carcinoma(HCC)and 46 healthy subjects were examined by contrast-enhanced CT scan(CTA)at 16-section CT scanner.Then the images were reconstructed with MPR,VR and MIP.Results RIPA were detected by CTA in all cases(sensitivity was 100%).The origin of RIPAs directly from the aorta in 42%,celiac trunk in 37%,right renal artery in 15%,left gastric artery in 3% and proper hepatic artery in 2%.For the reconstructive images quality,MPR and MIP were better than VR,but in showing the origin of RIPAs,MPR and VR were better than MIP.In compared with normal group,the diameters of RIPAs in tumor group were larger.Conclusion MDCT estimates well for the anatomy of RIPAs,which is significant for planning and embolization of extrahepatic RIPA supply in HCC.

Objective To discuss the functional results of percutaneons compressive screw fixation for float injury to the pubic symphysis. Methods From March 2003 to March 2007, 48 cases of float injury to the pubic symphysis were treated with percutaneons compressive screws, including 27 males and 21 females with an average age of 29.4 years. Of them, 39 eases were complicated with injury to the pelvic posterior ring. Emergency surgery was done for 13 cases, 27 cases were operated on within 3 to 7 days after injury and 8 within 7 to 14 days. Guided pins and screws were used during dosed reduction and percutaneous pelvic fixation was done under the guidance of intraoperative fluoroscopic imaging. Float injury to the pubic symphysis was amended by percutaneous fixation after dosed manipulation. Results The average operation time for the48 patients was 55 (31 to 100) min. The intraoperative bleeding averaged 20 to 30 mL. Satisfactory reduetian and fixation was achieved in 41 cases, but 7 cases had poor reduction. All the fractures healed 3 to 6 months postoperatively without infection, nonunion or injury to vessels, nerves or organs. All the patients could turn the body freely in bed the day after operation. Those without injury to the pelvic posterior ring could walk with crutches 3 days after operation. By the Orlando evaluation system for pelvic fractures, 37 eases were rated as excellent, 7 as good, 3 as fair and I as poor. Conclusions The percutaneous compressive screw fixation may decompress the pelvic hematoma, allowing early definitive fixation without the risk of additional hemorrhage. Complications associated with open posterior pelvic surgical procedures may be avoided by using percutaneons techniques.

Objective To observe the anatomical and biomechanieal properties of the forearm in terosseous membrane (IOM), providing the scientific theoretical basis for the diagnosis and treatment of the IOM injury. Methods Ten radius-IOM-ulna structures (left for 5 and right for 5) were harvested from 5 fresh-frozen adult cadavers to measure the length, width and thickness of the tendinous part. Then the tendi-nous part with its radial and ulnar insertions were isolated, embedding the proximal part of the radius and the distal part of the ttina in commercially available dental base acrylic resin powder. The embedded speci-mens were mounted on MTS 858 testing machine using a 10 000 N load cell for all tensile tests. The speci-mens were tested at a displacement rate of 50 mn/min until failure. The load-displacement curve was de-scribed by the computer while the maximum load and stiffness were recorded. Results The IOM consisted of three components: the tendinous part, the membranous part, and the dorsal oblique accessory cord. The IOM was fiat in the neutral position, while it flexed during the pronation and supination. Six specimens ob-tained the tear of tendinous portion at a maximum load of (1021.50±250.13) N. The stiffness was (138.24±24.29) N/mm with displacement to failure of (9.77±1.77) mm. Other 4 specimens failed by fracture through the ulnar fixed site before there was failure of the IOM at a maximum load of (744.40±109.85) N. The stiff-ness was (151.17±30.68) N/mm with displacement to failure of (6.51±0.51) ram. Conclusion The IOM has stiffness comparable to the ligament between the radius and the ulna and play an important role for the maintenance of longitudinal stability of the forearm. These results can provide objective criteria for the eval-uation of reconstructive methods.

Objective To compare the biomechanical properties of non-locking compression plate (DCP) and locking compression plate (LCP) in the internal fixation of humeral shaft fracture by means of finite element analysis.Methods Three-dimensional finite element models were constructed to simulate DCP and LCP internal fixation of humeral transverse fracture.The DCP and LCP groups were compared in terms of peak stress on the humeral fracture fragments (MPa),peak stress on the screws (MPa),and overall displacement peak value (mm) under 4 basic loads (bending,shear,torsion and compression).The biomechanical stability was analyzed after fracture fixation.Results The stress tended to concentrate at the connection sites of plate and screws and distributed evenly on DCP.The stress distributed in a gradient manner at the multiple screw holes and tended to concentrated on the central screws on LCP.Under the bending,shear and torsion loadings,the peak stresses on the fracture fragments and screws in the DCP fixation were larger than in the LCP fixation.However,under the compression loading,the peak stresses on the fracture fragments and screws in the DCP fixation were smaller than in the LCP fixation.DCP and LCP had similar trends in displacement.Under the bending,shear and torsion loadings,the overall displacement peak values in LCP fixation were smaller.However,under the compression loading,the overall displacement peak values in DCP fixation were smaller.Conclusions DCP and LCP have similar biomechanical properties to resist bending,shear,torsion and compression.Due to the gradient distribution of stress among the screw holes,LCP is more suitable for patients with comminuted fracture or osteoporosis.Stress distribution is more even in DCP.Surgeons should consider the advantages of both DCP and LCP to achieve better stability.

ObjectiveTo study the technique and therapeutic effect of percutaneous cannulate screw fixation to treat the traumatic diastasis of the pubic symphysis.MethodsFrom February 2003 to December 2010,46 patients (27 men and 19 women,mean age of 34.6 years) with unstable pelvic fractures and diastasis of the pubic symphysis were admitted.All the patients were treated by closed reduction and percutaneous cannulate screw fixation of the symphysis pubis.Then to complete the fixation of posterior ring,by percutaneous screw inserted through the sacroiliac joint or posterior iliac wing.According to Tile's classification,the patients were classified into type B1.1 in 4 cases,B1.2 in 7,B2 in 2,B3 in 2,C1.1 in 7,C1.2 in 7,C1.3 in 10,C2 in 5 and C3 in 2.All patients were performed posterior ring fixation except 4 cases of type B1.1.Anteroposterior,inlet and outlet X-ray radiographs and CT scans of the pelvis were taken preoperatively to evaluate the stability and deformities,and after surgery the plain radiographs and CT scans were taken to evaluate the reduction and the location of screws.ResultsThe average operative time was 45 min (range,15-65 min),and the average intraoperative blood loss was 25 ml (range,15-50 ml).Each patient was inserted one screw in the symphysis pubis.Thirty-five patients underwent postoperative pelvic CT scan and 3screws of them penetrated the wall of symphysis pubis.The average follow-up period was 23.5 months (range,5-48 months).In the follow-up period,no infection and displacement were found.The last follow-up result:according to Matta and Tornetta's standard,the result was excellent in 43 cases and good in 3.Among all patients,31 cases (67.39％) had returned to their original works,6 were to give up their original works as complicating injuries; 28 cases had no pain,13 cases had slight pain of the symphysis pubis while to make an effort,5 cases had pain of sacroiliac joint.There were no iatrogenic injury of nerve.ConclusionClosed reduction and percutaneous cannulate screw fixation of the traumatic diastasis of the pubic symphysis is a safe,feasible and easy manipulated method.The operative injuries is small and the clinical outcome is satisfactory.

Objective To evaluate the treatment methods for subtrochanteric femur fractures in children and adolescents.Methods Sixty-two patients (at age of 4-16 years) with subtrochanteric fe-mur fractures were managed with traction and delayed hip spica (14 patients, set as nonoperative group) ,titanium elastic nails or pin combined with cast (38 patients, set as less invasive group) and plates (10 patients, set as traditional operative group).The radiologic outcomes, hip joint function and complica-tions of the patients were analyzed.Results According to Beaty scoring, five patients in nonoperative group and 44 in operative group obtained satisfactory early radiologic outcomes.Late radiologic outcome was satisfactory in nine patients from nonoperative group and 46 from operative group according to Theolo-gis scoring, with statistical differences between two groups (P<0.05).Sanders scoring showed excellent results in 11 patients and good in three from nonoperative group, and excellent results in 43 and good in five from operative group, with no statistical differences between two groups (P > 0.05).Less invasive group and traditional operative group showed significantly statistical different in aspects of complications and Sanders scores (P < 0.05).Conclusions Operative treatment provides more satisfactory early and late radiologic results than nonoperative methods.Less invasive operations have better outcomes than tra-ditional operative methods.Selection of treatment modalities based on age, body weight, fracture features and soft tissue conditions of children is the prerequisite for a good outcome.

Objective To investigate the anatomical features, operative method and efficacy of internal fixation in the treatment of iutra-articular fractures of caleaneum via the sinus tarsi approach. Methods The pathway, branches distribution and anastomosis of perforating descending branch of peroneal artery were observed on 18 adult cadaveric lower limbs. A sinus tarsi approach was designed. From July 2001 to January 2008, 71 intra-articular calcaneal fractures in 68 patients were treated with open reduction and internal fixation via sinus tarsi approach at lateral sides of calcaneus. According to the Sanders classification, there were 26 type Ⅱ fractures, 32 type Ⅲ fractures and 13 type Ⅳ fractures. Results All patients were followed up for a mean period of 39.3 months (13-85 months), and the fractures were completely healed. There was a significant difference in the length, width and height of the calcaneus, Bohler angle and Gissane angle before and after operation (P < 0.01). According to Maryland Foot Score, the operative effect was excellent in 33 feet, good in 29 feet, fair in 6 feet and poor in 3 feet. Conclusion Open reduction and internal fixation via sinus tarsi approach is an effective method for minimally invasive treatment of intraarticular fractures of the calcaneus, with the advantages of good clinical results and causing minimal damage to soft tissues.

Objective To describe a technique of closed reduction and percutaneous internal fixation for the treatment of displaced patellar fractures and evaluate the clinical results. Methods Fifteen cases (nine males and six females with mean age of 35.5 years, ranging from 24 to 65 years) with displaced patellar fractures were treated with closed reduction (or an arthroscopic-assisted reduction) and percutaneous cannulated screw fixation (or Kirschner wire tension band wiring technique) under guidance of fluoroscopy or C-arm X-ray tomography. Controlled passive range of motion exercises started on the first postoperative day. The mean follow-up was 28 months (24-35 months). Results All cases healed successfully with healing time of (1.2?2.2) months and mean Lysholm II score of 86.8 (79-96), except for one patient regained full knee range of motion. Compared with the contralateral side, a mean quadriceps atrophy of 0.8 cm was seen in unilateral cases based on Tandogan measurement. There was no implant failure or postoperative infection. Conclusions The technique of closed reduction and percutaneous internal fixation is appropriate for displaced, transverse, longitudinal or oblique patellar fractures and can facilitate early postoperative range of motion exercises and accelerate rehabilitation of the affected knee with few complications and minor incision without disturbing blood supply of the patella. But, this method is not suitable for severely comminuted fractures.

Objective To discuss the 3D printing modeling used to assist minimally invasive fixation with hollow screws for unstable pelvic fractures.Methods From January 2014 to January 2016,137 patients with unstable pelvic fracture received minimally invasive fixation with hollow screws and obtained complete follow-up at our department.In 65 of them,the fixation was assisted by 3D printing modeling;they were 37 men and 28 women,with an average age of 33.1 ± 4.9 years.In the other 72 cases,conventional fixation was performed without assistance of 3D printing modeling;they were 45 men and 27 women,with an average age of 32.6 ±4.7 years.The 2 groups were compared in terms of operation time,frequency of intraoperative fluoroscopy,reduction quality and curative effect.Results This cohort were followed up for 6 to 15 months (average,9 months).The 3D printing modeling group needed significantly less operation time (58.6 ± 13.4 min) and intraoperative fluoroscopy (29.3 ± 3.6 frequencies) than the conventional group (72.4 ± 12.4 min and 36.6 ± 2.8 frequencies) (P ＜ 0.05).According to the Matta scoring criteria,the quality of pelvic reduction was evaluated as excellent in 21 cases,as good in 30 cases,as fair in 13 cases and as poor in one in the 3D printing group,yielding an excellent and good rate of 78.5％ while as excellent in 22 cases,as good in 36 cases,as fair in 12 cases and as poor in 2 cases in the conventional group,yielding an excellent and good rate of 80.6％.According to the Majeed scoring criteria,the curative effect was evaluated at the last follow-up as excellent in 27 cases,as good in 26 cases,as fair in 11 cases and poor in one in the 3D printing group,giving an excellent and good rate of 81.5％ while as excellent in 30 cases,as good in 28 cases,as fair in 13 cases and as poor in one in the conventional group,giving an excellent and good rate of 80.6％.There were no statistically significant differences between the 2 groups in reduction quality or curative effect (P ＞ 0.05).No nonunion or iatrogenic neurovascular lesions happened during the follow-up period.Conclusion 3D-printing modeling is helpful for a good reduction and minimally invasive fixation with hollow screws for unstable pelvic fractures by reducing operation time and intraoperative fluoroscopy.