带蒂鼻底黏膜瓣联合自体筛骨垂直板修补鼻中隔穿孔的临床观察

目的 回顾性分析带蒂鼻底黏膜瓣联合自体筛骨垂直板修补鼻中隔穿孔的疗效。方法 19例鼻中隔穿孔患者均采用鼻内镜下带蒂鼻底黏膜瓣联合筛骨垂直板修补鼻中隔穿孔,并采用纳吸棉对术后创面行填塞止血。结果19例行鼻中隔穿孔修补的患者术后随访1~3个月,17例(89.47%)患者鼻中隔黏膜均愈合良好,穿孔均修补成功,且形态恢复良好,2例(10.52%)患者因术后未能按时随访,未能观察疗效。结论 采用带蒂鼻底黏膜瓣联合自体筛骨垂直板修补鼻中隔穿孔,自体组织取材方便,经济实惠,无排异反应,带蒂鼻底黏膜瓣血供好,修补成活率高,疗效可靠。

Quantitative Histological Study on Changes of the Cortical Bones after Internal Fixation with Plates of Different Rigidity

In an effect to explore the potemtial role of bone microcirculation causing plate-induced reginal osteoporosis

EFFECT OF INTERNAL FIXATION PLATES ON MICROCIRCULATION IN UNDER-PLATE CORTICAL BONES MICROANGIOGRAPHY AND SCANNING ELECTRONMICROSCOPY

To elucidate the effect of the internal fixation plates on the local bone blood sapply, we used microangiography and scanning electron microscopy to observe the morphological changes of microcirculation in the cortical bones obtained from intact rabbit tibiae on which plates of two different stiffness had been fixed for comparison. The results indicated that both rigid stainless steel plate and less rigid methyl methacrylate plate could induce the bone microcirculation under the plate to undergo a process from early depression to late reactive recruitment. The features of the microcircuiation recruitment such as vascular number, arrangement and dilatation varied with plates of different stiffness and were more obvious in the cortex fixed by rigid stainless steel plate.

A novel biomimetic trabecular bone metal plate for bone repair and osseointegration

Fracture is one of the most common traumatic diseases in clinical practice,and metal plates have always been the first choice for fracture treatment because of their high strength.However,the bone plates have high elastic modulus and do not match the biomechanics of human bone,which adversely affects callus formation and fracture healing.Moreover,the complex microenvironment in the human body can induce corrosion of metallic materials and release toxic ions,which reduces the biocompatibility of the bone plate,and may necessitate surgical removal of the implant.In this study,tantalum(Ta)was deposited on porous silicon carbide(SiC)scaffolds by chemical vapor deposition technology to prepare a novel porous tantalum(pTa)trabecular bone metal plate.The function of the novel bone plate was evaluated by implantation in an animal fracture model.The results showed that the novel bone plate was effective in fracture fixation,without breakage.Both X-ray and microcomputed tomography analysis showed indirect healing by both pTa trabecular bone metal plates and titanium(Ti)plates;however,elastic fixation and obvious callus formation were observed after fixation with pTa trabecular bone metal plates,indicating better bone repair.Histology showed that pTa promoted the formation of new bone and integrated well with the host bone.Therefore,this novel pTa trabecular bone metal plate has good prospects for application in treating fractures.

Comparative prospective study between medial and lateral distal tibial locking compression plates for distal third tibial fractures

Purpose： Tibial fracture is the most common long bone fracture. Distal third tibial fractures are chal- lenging though open reduction and plating can result in anatomical reduction and rigid fixation. This paper aimed to evaluate and compare the results of medial and lateral locking compression plates for distal third tibial fractures. Methods： This prospective clinical study involved 36 patients with distal tibial fractures admitted in Department of Orthopaedics, Sawai Mansingh Medical College ＆ Affiliated Hospital, Jaipur, India, from June 2011 to May 2012, including 29 closed fractures and 7 open fractures at the mean age of 38.9 years. Thirty-six patients were divided equally into two groups based on treatment method, including medial plating group （18 patients） and lateral plating group （18 patients）. They were followed up for at least 5 months after discharge. The functional outcomes were evaluated using Tenny and Wiss clinical assess- ment criteria. Results： Malunion was found in 3 cases of medial plating group and in 1 case of lateral plating group. In the medial plating group, there were 5 cases of superficial infections, 1 deep infection, 1 nonunion and 3 wound dehiscence. In the lateral plating group, there was 1 case of superficial infections, 1 deep infection and 1 nonunion, in the lateral plating group, 4 patients reported feeling the plates and screws but none of them asked to remove the hardware. In the medial plating group, 9 patients reported symptomatic hardware problems and 7 asked to remove the hardware. The number of cases graded as excellent/good/ fair was 1/8/7 in the medial plating group and 3/7/7 in the lateral plating group respectively. In the medial plating group, the final range of motion was 17.2° in ankle dorsiflexion and 30.7° in ankle plantar flexion. In the lateral plating group, the final range of motion was 19° in ankle dorsiflexion and 34.2° in ankle plantar flexion. Conclusion： Lateral plating of distal tibia is safe and feasible, which can provide biological fixation and prevent the soft tissue complications associated with medial plating.

Role of locking plates in treatment of difficult ununited fractures： a clinical study

Objective： To present our experience in treatment of difficult ununited long bone fractures with locking plate. Methods： Retrospective evaluation of locking plate fixation in 10 difficult nonunions of long bone fractures was done. Fixation was done with locking plate for femoral shaft fracture （3 patients）, supracondylar fracture of femur （gap nonunion）, fracture of clavicle, fracture of both forearm bones （radius and ulna） fracture of ulna, fracture of shaft of humerus, fracture of tibial diaphysis and supracondylar frac- ture of humerus （one patient each）. Five fractures had more than one previous failed internal fixation. One patient had infected nonunion which was managed by debridement with cast immobilization followed by fixation with locking plate at six weeks. Seven fractures were atrophic, two were oligotrophic, and one was hypertrophic. Fibular autograft was used in 2 cases and iliac crest cancellous bone graft used in all the patients. Results： Minimum follow-up was 6 months （range, 6 months to 2.5 years）. Average time for union was 3.4 months （range 2.5 to 6 months）. None of the patients had plate- related complications or postoperative wound infections. Conclusion： Along with achieving stability with locking compression plate, meticulous soft tissue dissection, acceptable reduction, good fixation technique and bone grafting can help achieve union in difficult nonunion cases. Though locking plate does not by itself ensure bony union, we have found it to be another useful addition to our armamentarium for treating difficult fracture nonunions.

Locking plates in distal humerus fractures： study of 43 patients

Objective： The treatment of multi- fragmentary, intraarticular fractures of the distal humerus is difficult, even in young patients with bone of good quality. Small distal fragment, diminished bone mineral quality and increased trauma-associated joint destruction make stable joint reconstruction more problematic. The anatomically preshaped locking plates allow angular stable fixation for these complex fractures. We evaluated functional results of patients treated with open reduction and internal fixation with distal humerus locking plates for complex distal hu- merus fractures. Methods： Forty-three consecutive patients with ar- ticular fractures of the distal humerus were treated by open reduction and internal fixation with AO distal humerus plate system and locking reconstruction plates. Forty patients were available for the final outcome analysis. According to AO/ASIF classification, there were 2 cases of type A2, 4 cases of type A3, 1 case of type B1, 1 case of type B2, 14 cases of type C1, 7 cases of type C2 and 11 cases of type C3. Open reduction with triceps splitting technique was used in all patients. The clinical and radiographic follow-up was performed and outcome measures included pain assessment,range of motion, and Mayo elbow performance score. Results： Forty patients were available for the final outcome analysis. There were 29 males and 11 females with an average age of 38.4 years （18-73 years）. Clinical and ra- diological consolidation of the fracture was observed in all cases at an average of 11.6 weeks （9-14 weeks）. The average follow-up was 12 months （10-18 months）. Using the Mayo elbow performance score the results obtained were graded as excellent or good results in 33 patients （82.5%）. One pa- tient had superficial infection, and 4 had myositis ossificans. There were no cases of primary malposition or secondary displacement, implant failure or ulnar neuropathy. Conclusion： Anatomically preshaped distal humerus locking plate system is useful in providing stable fixation for complex distal articular fracture and facilitating early post- operative rehabilitation. The low rate of implant failure in the present study indicates that the technique is promising and warrants further investigation.

The biomechanics of point contact-dynamic compression plate and its effects on bone perfusion

Objective： To compare the mechanical properties of point contact-dynamic compression plate （PC-DCP） and its effects on cortical bone perfusion with that of dynamic compression plates （DCP） in goat tibiae. Methods： Twenty pairs of matched flesh goat tibiae were used. A transverse fracture model was established. The fractures with a 3ram interspace between the fracture ends were subject to fixations with the DCPs and the PC- DCPs respectively, then the four-points bending tests and the torsion tests were conducted to compare the mechanical properties of the PC-DCP with that of DCP. Another 13 sexually mature goats underwent fixations with the DCPs and the PC-DCPs, respectively, at the mid-shafts of the intact bilateral tibiae. Ischemic zones were observed at four time points （1 day, 2, 6, and 12 weeks after operation） using disuiphine blue staining technique. Remits： There were no significant differences in mechanical properties, such as bend- and torsionresistance, between the DCPs and the PC-DCPs. One day, 2, and 6 weeks after operation, on the side of DCP fixation, outer cortical bone ischemia under the plate persisted, and this condition did not reverse until 12 weeks after operation. However, on the side of PC-DCP fixation, cortical bone iscbemia occurred only in the periphery of the screw holes and at the contact sites of the PC NUTs 1 day after operation, and it disappeared at 2 weeks after operation. Conclusions： The PC-DCP has similar biomechanical properties of the DCP, but is less detrimental to local bone blood circulation than the conventional plates.

Dsteosynthesis with long volar locking plates for meta- physeal-diaphyseal fractures of the distal radius

Objective：Metaphyseal-diaphyseal fractures of the distal radius are a major treatment dilemma and orthopaedic surgeons have to pay due consideration to restoration of anatomy of distal radius together with rotation of the radial shaft and maintenance of radial bow and interosseous space.We performed this study to evaluate the clinic-radiological outcome of metaphyseal-diaphyseal fractures of the distal radius treated with long volar locking plates.Methods：This prospective study involved 27 patients （22 males and 5 females） with metaphyseal-diaphyseal fracture of the distal radius.Their mean age was （30.12±11.48） years （range 19-52 years） and the follow-up was 26.8 months （range 22-34 months）.All patients underwent open reduction and internal fixation with a long volar locking plate.According to AO/OTA classification,there were 7 type A3,13 type C2 and 7 type C3 fractures.Subjective assessment was done based on the disabilities of the arm,shoulder and hand （DASH） questionnaire.Functional evaluation was done by measuring grip strength and range of motion around the wrist and the radiological determinants included radial angle,radial length,volar angle and ulnar variance.The final assessment was done according to Gartland and Werley scoring system.Results：Postoperative radiological parameters were well maintained throughout the trial,and there was significant improvement in the functional parameters from 6 weeks to final follow-up.The average DASH scores improved from 37.5 at 6 weeks to 4.2 at final follow-up.Final assessment using Gartland and Werley scoring system revealed 66.67%（n=l8） excellent and 33.33% （n=9） good results.There was one case of superficial infection which responded to antibiotics and another carpel tunnel syndrome which was managed conservatively.Conclusion：Volar locking plate fixation for metaphyseal-diaphyseal fractures of distal radius is associated with excellent to good functional outcome,early rehabilitation and minimal complications.

Experimental study of effect of stress-relaxation bone plate on fracture healing

To study the change of the stress shielding rate of stress-relaxation plate in vivo and its influence on fracture healing. Methods: The diaphyses of bilateral tibias in 70 New Zealand rabbits were osteotomized and fixed with stress-relaxation plates (SRP, the SRP group) and rigid plates (RP, the RP group), respectively. The fracture healing process in these 2 groups was investigated by radiography, light and polarized light microscopy and biomechanical test at 2 to 48 weeks postoperatively. Results: Early after fixation the stress shielding rate was about 70% in both groups. While in the SRP group the stress shielding rate decreased gradually as time passed, which was significantly lower than that of the RP group (P< 0.05 ) by the end of the 8th postoperative week, and stabilized at the level of about 27% at 36-48 weeks after fixation. Abundant external callus associated with the formation of cartilaginous callus could be observed in the SRP group at 2-4 weeks postoperatively. The transformation of the callus into the lamellar bone began at 8-12 weeks, the collagen gradually arranged in order, and the mechanical nature of the united bone was gradually strengthened, too. In the RP group, the external callus was scarce at the early stage of fracture healing, and the callus remodeling at the late stage of fracture healing was dominated by bone absorption. The ultimate bending strength (UBS) was only 57.95 % of that of the normal by 48 weeks. Conclusions: The decrease of the stress shielding rate of SRP in vivo was well interrelated with the time of fixation. The application of SRP could promote the callus formation and bone reconstruction thus to favor the recovery of the mechanical strength of the united bone.

The effects of stress relaxation plate on disorganization and repair of regional bone structure: an experimental study

To study the influence of stress relaxation plate on disorganization and repair of the cortex beneath the plate. Methods: A washer made of viscoelastic polyethylene was placed between the screw and the screw hole of conventional stainless rigid plate (RP) to produce a stress relaxation plate (SRP). Both SRP and RP were applied to osteotomized tibia in 48 New Zealand rabbits. Healing process of the fracture with either SRP or RP fixation (control) was comparatively studied with polarized light microscopy, in situ hybridization of collagen mRNA and immunohistochemical technique from 2 to 36 weeks postoperatively. Results: The study of plated bone remodeling showed that the degree of cortex osteoporosis beneath the plate was similar between the SRP and RP group within 12 weeks postoperatively. In comparison, the disorganization of bone structure in SRP group happened later and milder than that of RP group, and the repair process began at 12 weeks after implantation. As a consequence, the absorption cavities became smaller and the structure of collagen fibers became well oriented along with these changes by polarized light microscopy. In addition to these, the in situ hybridization analysis of collagen genes and the immunohistochemical study of type Ⅰ, Ⅲ collagen showed that the osteoblasts lying on the surface of absorption cavities expressed and synthesized type Ⅰ collagen at 8 to 12 weeks after implantation. From this time on, the changes above became more evident significantly before most of cavities were repaired by 36 weeks. In contrast to the changes in the SRP group, no expression and synthesis of any kind of collagen could be observed during 12 to 36 weeks after implantation in RP group. Conclusions: Without removal of the bone plate, the SRP fixation not only reduces the degree of plated bone osteoporosis, but also makes the disorganized bone structure restored to normal in terms of the expression and synthesis of type Ⅰ collagen mRNA of osteoblasts lying on the surface of absorption cavities.

Experimental study of a 3D printed permanent implantable porous Ta-coated bone plate for fracture fixation

Metal plates have always been the gold standard in the clinic for internal fracture fixation due to their high strength advantages.However,high elastic modulus can cause stress shielding and lead to bone embrittlement.This study used an electron beam melting method to prepare personalized porous Ti6Al4V(pTi)bone plates.Then,chemical vapor deposition(CVD)technology coats tantalum(Ta)metal on the pTi bone plates.The prepared porous Ta-coated bone plate has an elastic modulus similar to cortical bone,and no stress shielding occurred.In vitro experiments showed that compared with pTi plates,Ta coating significantly enhances the attachment and proliferation of cells on the surface of the scaffold.To better evaluate the function of the Ta-coated bone plate,animal experiments were conducted using a coat tibia fracture model.Our results showed that the Ta-coated bone plate could effectively fix the fracture.Both imaging and histological analysis showed that the Ta-coated bone plate had prominent indirect binding of callus formation.Histological results showed that new bone grew at the interface and formed good osseointegration with the host bone.Therefore,this study provides an alternative to bio-functional Ta-coated bone plates with improved osseointegration and osteogenic functions for orthopaedic applications.

Stress-relaxation plates and the remodeling of callus and cortex under the plate in rabbits

To study the influence of a stress-relaxation plate on the remodeling of callus and cortex under the plate Methods The bilateral tibia diaphysis of New Zealand rabbit were osteotomized and fixed with stress-relaxation plate (SRP) and rigid plate (RP), respectively Polarized light microscopy and transmission electron microscopy (TEM) were used to study the remodeling of callus and the cortex under the plate from 4 to 24 weeks postoperatively Results Polarized light microscopy: the structural changes of callus and cortex beneath the plate are similar in the SRP and RP groups at the early postoperative stage, manifesting an alignment disorder of collagen fibers with a weak birefringence in the callus and absorption cavities in the cortex under the plate After the twelveth postoperative week, the SRP group showed callus starting to transform to lamellar bone and absorption cavities in the cortex under the plate becaming smaller By contrast in the RP group the absorption cavities in the callus and cortex under the plate became larger and the whole layer of cortex was cancellated TEM: the active osteoclasts appeared in both SRP and RP groups in the period from 4 to 8 weeks postoperatively In the SRP group, many functionally active osteoblasts could be seen on the surface of the bone, while in the RP group, the osteoblasts were not very active By 24 weeks postoperatively, the shape of osteocytes were normal but the number of the osteoclasts were small in the SRP group In the RP group, the osteoclasts became more active and osteocytic osteolysis was manifested Conclusions Fixation with SRP not only enhanced callus remodeling, but also abated the degree of osteoporosis in the cortex under the plate This approach may lead to an improved osteosynthetic apparatus

A mechanical study of personalised Ti6Al4V tibial fracture fixation plates with grooved surface by finite element analysis

Low shape matching and high stress shielding rates between bone plate and human bone are not conducive to the primary healing of fracture.In this study,taking the fracture site of the lower one‐third of human tibia as an application case,six types of personalised Ti6Al4V tibial plates with grooved surface were designed and evaluated by reverse en-gineering and finite element analysis.The results showed that the grooved design can reduce the stress shielding rate of bone plate and promote the facture healing.Among the six types of bone plates,the‘OUT-MI’bone plate has the lowest stress shielding rate and the most uniform stress distribution.Meanwhile,with the increasing tibial load during the convalescence,the average stress and maximum axial displacement of the tibial fracture surface increased,which can effectively improve the bone regeneration in the tibial fracture area.Moreover,there was no significant difference in four-point bending performance between the‘OUT-MI’bone plate and the‘STR-BE’bone plate,indicating that the mechanical properties of this bone plate were reliable.The results provide a theoretical basis for the design of fracture fixation plates on clinical treatment.

Piezoelectric-Based Smart Bone Plate for Fracture Healing Progress Monitoring

Fracture healing progress monitoring techniques attract global research attention due to the importance of selecting the timing of removing the fixation device.To this end,in this research,we present a piezoelectric-based smart internal fixation device,in which a piezoelectric sandwich structure is laminated to the surface of a bone plate.In the content,we explain the reasons for utilizing piezoelectric films,elaborate the mechanism of fracture monitoring,and introduce the mechanical parameters of the sensor.The simulation and experimental results show that the electrical output of the device is associated with the elastic modulus of the filler between the tested broken bones when the working load is maintained,indicating that the bone recovery progress could be successfully detected by the developed technique.

Influence of Medial Support Screws on the Maintenance of Fracture Reduction after Locked Plating of Proximal Humerus Fractures

Background： Technical aspects of the correct placement of medial support locking screws in the locking plate for proximal humerus fractures remain incompletely understood. This study was to evaluate the clinical relationship between the number of medial support screws and the maintenance of fracture reduction after locked plating of proximal humerus fractures. Methods： We retrospectively evaluated 181 patients who had been surgically treated for proximal humeral fractures （PHFs） with a locking plate between September 2007 and June 2013. All cases were then subdivided into one of four groups as follows： 75 patients in the medial cortical support （MCS） group, 26 patients in the medial multiscrew support （MMSS） group, 29 patients in the medial single screw support （MSSS） group, and 51 patients in the 11o medial support （NMS） group. Clinical and radiographic evaluations included the Constant-Murley score （CM）, visual analogue scale （VAS）, complications, and revision surgeries. The neck-shaft angle （NSA） was measured in a true anteroposterior radiograph immediately postoperation and at final follow-up. One-way analysis of variance or KruskaI-Wallis test was used for statistical analysis of measurement data, and Chi-square test or Fisher＇s exact test was used for categorical data. Results： The mean postoperative NSAs were 133.46°± 6.01°, 132.39° ± 7.77°. 135.17° ± 10.15°, and 132.41° ± 7.16° in the MCS, MMSS, MSSS, and NMS groups, respectively, and no significant differences were found （F = 1.02, P= 0.387）. In the final follow-up, the NSAs were 132.79° ±6.02°, 130.19° ± 9.25°, 131.28° ± 12.85°, and 127.35° ± 8.50° in the MCS, MMSS, MSSS, and NMS groups, respectively （F = 4.40, P = 0.008）. There were marked differences in the NSA at the final follow-up between the MCS and NMS groups （P = 0.004）. The median （interquartile range [IQR]） NSA losses were 0.0° （0.0-1.0）°, 1.3° （0.0-3.1）°, 1.5° （ 1.0-5.2）°, and 4.0° （ 1.2 -7.1 ）° in the MCS, MMSS, MSSS, and NMS groups, respectively （H = 60.66, P 〈 0.001 ）. There were marked differences in NSA loss between the MCS and the other three groups （MCS vs. MMSS, Z = 3.16, P = 0.002; MCS vs. MSSS, Z = 4.78, P 〈 0.001; and MCS vs. NMS, Z = 7.34, P 〈 0.001）. There was also significantly less NSA loss observed in the MMSS group compared to the NMS group （Z = -3.16, P = 0.002）. However, there were no significant differences between the MMSS and MSSS groups （Z = -1.65, P = 0.225） or the MSSS and NMS groups （Z =- 1.21, P = 0.099）. The average CM scores were 81.35 ± 9.79, 78.04± 8.97, 72.76 ± 10.98, and 67.33 ± 12.31 points in the MCS, MMSS, MSSS, and NMS groups, respectively （F = 18.68, P 〈 0.001）. The rates of excellent and good CM scores were 86.67%, 80.77%, 65.52%, and 43.14% in the MCS, MMSS, MSSS, and NMS groups, respectively （ X^2 = 29.25, P 〈 0.001 ）. The median （IQR） VAS scores were 1 （0-2）, l （0 2）,2 （ 1-3）, and 3 （1-5） points in the MCS, MMSS, MSSS, and NMS groups, respectively （H = 27.80, P 〈 0.001）. Functional recovery was markedly better and VAS values were lower in the MCS and MMSS groups （for CM scores： MCS vs. MSSS, P 〈 0.001 ; MCS vs. N MS. P 〈 0.001; MMSS vs. MSSS, P= 0.031 and MMSS vs. NMS, P 〈 0.001 and for VAS values： MCS vs. MSSS, Z=3.31, P = 0.001： MCS vs. NMS, Z = 4.64, P 〈 0.001; MMSS vs. MSSS, Z = -2.09, P = 0.037： and MMSS vs. NMS, Z=-3.16, P = 0.003）.Conclusions： Medial support screws might help enhance mechanical stability and maintain fracture reduction when used to treat PHFs with medial metaphyseal comminution or malreduction.

The anatomical study of transoral atlantoaxial reduction plate internal fixation

Objective： To study relevant anatomical features of the structures involved in transorai atlanto-axiai reduction plate （TARP） internal fixation through transorai approach for treating irreducible atlanto-axiai dislocation and providing anatomical basis for the clinical application of TARP. Methods： Ten fresh craniocervicai specimens were microsurgicaily dissected layer by layer through transorai approach. The stratification of the posterior pharyngeal wail, the course of the vertebral artery, anatomical relationships of the adjacent structures of the atlas and axis, and the closely relevant anatomical parameters for TARP internal fixation were measured. Results： The posterior pharyngeal wall consisted of two layers and two interspaces： the mucosa, prevertebrai fascia, retropharyngeai space, and prevertebrai space. The range from the anterior edge of the foramen magnum to C3 could be exposed by this approach. The thickness of the posterior pharyngeal wall was （ 3.6 ± 0.3 ） mm （ranging 2.9-4.3 mm） at the anterior tubercle of C1, （6.1 ±0.4） mm （ ranging 5.2-7.1 mm） at the lateral mass of C1 and （5.5±0.4） mm （ranging4.3-6.5 mm） at the central part of C2, respectively. The distance from the incisor tooth to the anterior tubercle of C1, C1 screw entry point, and C2 screw entry point was （82.5 ±7.8） mm （ranging71.4-96.2 mm）, （90. 1 ±3.8） mm （ranging 82.2-96.3 mm）, and （89.0±4.1） mm （ranging 81.3- 95.3 mm）, respectively. The distance between the vertebral artery at the atlas and the midline was （25.2 ± 2.3） mm （ ranging 20.4-29.7 mm ） and that between the vertebral artery at the axis and the midline was （ 18.4 _ 2.6 ） mm （ ranging 13.1-23.0 mm）. The allowed width of the atlas and axis for exposure was （39.4 ±2. 2） mm （ ranging 36.2-42. 7 mm ） and （ 39.0 ± 2.1 ） mm （ ranging 35.8-42.3 mm ）, respectively. The distance （ a ） between the two atlas screw insertion points （center of anterior aspect of C1 lateral mass ） was （ 31.4 ± 3.3 ）mm （ ranging 25.4-36.6 mm）. The vertical distance （b） between the line connecting the two C1 screw entry points and that connecting the two C2 screw entry points （at the central part of the vertebrae, namely 3-4 mm lateral to the midline of C2 vertebrae） was （21.3±2.7） mm （ranging 19.4- 24.3mm）, with an a/b ratio of 1.3-1.5. The screws of TARP had a lateral tilt of 12.2°± 0.4° （ranging 10.2° -14.6°at C1 and a medial tilt of 7.3°±0.3° （ranging5.1°-9.4°） at C2 relative to the coronal plane. Conclusions ： An atlanto-axiai surgery through transorai approach is safe and feasible. This approach is suitable for an anterior TARP internal fixation, and the design of the internal fixation system should be based on the above anatomical data.

Locking internal fixator with minimally invasive plate osteosynthesis for the proximal and distal tibial frac- tures

Objective： To investigate the efficacy of the locking internal fixator （LIF）, which includes the locking compression plate （LCP） and the less invasive stable system （LISS）, in the proximal and distal tibial fractures. Methods： We did a retrospective study on a total of 98 patients with either proximal or distal tibial fractures from January 2003 to January 2007, who had received the opera- tion with LIF by the minimally invasive plate osteosynthe- sis （MIPO） technique. The data consisted of 43 proximal tibial fractures （type AO41 C3） and 55 distal tibial fractures （type AO43C3）. Results： No complications were observed in all patients after operation. The mean healing time was 8.4 months （range 5-14 months）. Only two cases of delayed union oc- curred at postoperative 10 months. No infections were re- ported after the definitive surgery even in the cases of open fractures. All patients reached a full range of motion at post- operative 6 to 9 months and regained the normal functions of knee and ankle joints. Conclusion： Using LIF in MIPO technique is a reliable approach towards the proximal and distal tibial fractures that are not suitable for intramedullary nailing.

Dynamic hip screw with locking side plate： a viable treatment option for intertrochanteric fracture

Objective： Dynamic hip screw （DHS） is recommended for the fixation of stable intertrochanteric fractures. Its postoperative cut-out rate ranges from I% to 6%. In osteoporotic bone, normal screws in DHS blade provide less anchorage compared to locking screws. This study aims to compare DHS with locking side plate and conventional side plate. Methods： Fifty consecutive patients with intertrochanteric fractures were randomly allocated for fixation with a standard DHS （group A） and locking DHS （Combi plate, group B）. We compared the clinical and radiological outcomes for the conventional DHS and locking DHS in intertrochanteric fractures. Functional outcome was evaluated using the Parker mobility score. Results： Coxa valga was found more frequently in group A than in group B （12% vs. 0%, P=0.42）. Coxa vara showed the same trend （12% vs. 8%, P=0.81）. Rate of restoration of postoperative neck-shaft angle within 20° of sound side was higher in group B （8% cases） than in group A （4% cases, P=0.98）. The rate of anteversion angle restoration within 10° of sound side was also higher in group B （100% vs. 88%, P=0.85）. The average lag screw slippage in group A and group B was 3.2 mm and 4.2 mm, the average fracture union duration was 17.1 weeks and 16.4 weeks, and the mean Parker score was 5.6 and 5.8 respectively. Screw cut-out was seen in one patient in group A. No cut-out was seen in any of the patient in group B. No patient developed deep infection, avascular necrosis, deep vein thrombosis or any other significant complications. Conclusion： The present study demonstrated that treating intertrochanteric fracture with a locking DHS allows sound bone healing and is not associated with any major complications. Although this report is promising, it should be interpreted with caution because only a prospective study with a large sample size would allow definitive conclusion.

Comparative study of perpendicular versus parallel double plating methods for type C distal humeral fractures

Background Double plate osteosynthesis is the standard treatment for intra-articular fractures of the distal humerus.However,there is still controversy concerning dual plate positions in terms of providing optimal stability.The purpose of this retrospective study was to compare the clinical outcomes in patients with type C intra-articular distal humeral fractures using perpendicular and parallel plating methods.Methods Between March 2008 and June 2011,a total of 45 patients with type C distal humerus fractures were treated using two different dual plating methods.Of them,24 patients were treated by perpendicular plating （group Ⅰ） and 21 patients were treated by parallel plating （group Ⅱ）.The surgical time,blood loss,and union time were compared between the two groups.The fiexion-extension arc,the total range of flexion and extension at the end of follow-up were compared between the two groups.The Mayo Elbow Performance Score （MEPS） was used to determine the elbow functional results.Results All patients were followed up.The mean duration of follow-up was 16 months （range 12-25 months） in group Ⅰ and 15.5 months in group Ⅱ （range 12-25 months）.There were no significant differences in the surgical time,blood loss,and the bone union time between the two groups.In group Ⅰ,the mean elbow flexion-extension arc was 101° and the mean MEPS was 85 points.The rate of excellent and good results was 87.5%.In group Ⅱ,the mean flexion-extension arc was 100° and the mean MEPS was 86.1 points.The rate of excellent and good results was 90.5%.There were no significant differences in the MEPS,flexion-extension arc,and the total range of flexion and extension between the two groups.Conclusions Perpendicular and parallel plate configurations with the appropriate surgical techniques can provide anatomical reconstruction and stable fixation of type C intra-articular distal humeral fractures and allow early mobilization of the elbow after an operation.The occurrence of post-operative elbow stiffness can be reduced and good outcomes can be obtained.