Limb length discrepancy is caused by either congenital or acquired conditions,such as growth arrest,osteomyelitis,trauma or tumor.Conventional Limb lengthening utilizes external fixators which lead to great inconvenience to patient's daily life.Complications are however common including pin-site infection,soft tissue tethering from the pins and wires resulting in pain,regenerate deformity or fracture after frame removal and intolerance of the frames.In order to reduce the time of external fixator treatment,various combinations techniques of both external and internal fixation have been developed.However,there is still a risk of deep infection of the implant due to contamination of the previous pin tracts of the external fixation.Fullly implantable intramedullary lengthening nail can avoid the problems of external fixator,including discomfort,pin sites infection,muscular transfixation and soft tissue tethering.There are still some problems including serious pain,too quick lengthening and authorization,so the earlier generations of products could not be safely and widely used.The newest generation of magnetic intramedullary lengthening nail represented by PRECICE (NuVasive,Inc.,Irvine,CA,USA) has obtained good early clinical results with its stability,precision and controllability.PRECICE is broadly used in the world,which may become the new direction of treatment for limb lengthening and deformity correction.This article aims to review the recent development of fully implantable intramedullary lengthening nail,including clinical application,preoperative planning,key points of surgery,postoperative rehabilitation,and complications.

Objective:To evaluate the safety and feasibility of the in-situ needle fenestration combined with the in vitro physician modified fenestration technique to reconstruct supra-aortic branches during thoracic endovascular aortic repair (TEVAR) for aortic arch lesions requiring landing at Z0 and Z1.Methods:From Nov 2017 to Dec 2019, eighteen patients who underwent both the in-situ needle fenestration and the in vitro physician modified fenestration techniques to extend the proximal landing zone to Z0 and Z1 during TEVAR were included in our study.Results:Sixteen patients underwent in vitro physician modified fenestration ,two patients underwent in vitro physician modified fenestration to reconstruct both the left common carotid artery and the innominate artery. All eighteen patients received in-situ needle fenestration to preserve the left subclavian artery. Supra aortic branches were preserved in all patients (38/38, 100%). There was no Type Ⅰ endoleak. Type Ⅱ endoleak was found in four paitnets (4/18). Type Ⅲ endoleak occurred in one patient (1/18). Type Ⅳ endoleak in four patients (4/18). Type Ⅲ endoleak needed open aortic arch repair 6 months later. The median follow-up time was 12 months. One (1/18) died in 12 months and the other patients were doing well.Conclusions:The joint application of the in-situ needle fenestration and the in vitro physician modified fenestration to reconstruct supra-aortic branches during TEVAR for aortic arch pathologies requiring landing at Z0 and Z1 was satisfactory.

Objective To evaluate the clinical effects of the Ilizarov method combined with two kinds of reversed neurocutaneous island flaps transfer for posttraumatic equinus with soft tissue defects on ankle and foot.Methods Data of 21 cases of posttraumatic equinus with soft tissue defects on ankle and foot who were treated with the Ilizarov external fixation combined with the two kinds of reversed neurocutaneous island flaps transfer from June 2006 to January 2018 were retrospectively analyzed.There were 17 males and 4 females,aged from 26 to 65 years,with an average age of 43.9 years.The soft tissue defect dimensions ranged from 6 cm×5 cm to 10 cm×9 cm,and the time from the initial trauma to the operation ranged from 2.5 to 240.0 months.The mean preoperative equinus contracture was-38.9° (range,-25° to-66°),and total ankle range of motion (ROM) was 7.1° (range,0°-18°).All cases were treated with the Ilizarov external fixation combined with the two kinds of reversed neurocutaneous island flaps transfer.Two weeks after the flap transfer,distraction of the Ilizarov fixator was initiated to gradually correct the equinus foot.The flap survival was observed in the postoperative period,and the International Club Foot Study Group (ICFSG) score was collected at the latest follow-up.The criteria were used to assess the morphological and functional outcome.Results A total of 21 resversed flaps were transferred,including 15 sural neurocutaneous flaps and 6 saphenous neurocutaneous flaps.The sizes of flaps were from 7 cm±6 cm to 11 cm± 10 cm.Among them,17 patients underwent primary flap transfer,and 4 patients underwent a delayed second-stage procedure 2 weeks after primary surgery.The 4 delayed flaps contain 3 sural neurocutaneous flaps and 1 saphenous neurocutaneous flap.All 21 patients were followed up and the average periodof follow-up was 20.3 months (range,8-96 months).Among the 21 flaps,19 survived completely.Although marginal necrosis was observed in 2 cases,these wounds healed after subsequent debridement and dressing change treatment.No major complication was seen,but superficial pin tract infection was present in 4 cases who then received dressing change and oral antibiotic.Deformities were corrected,and ankle motion had increased significantly.The mean ankle activity at the latest follow up was 22° (range,8°-38°),and postoperative ICFSG score at the latest follow-up was 5.67±3.09,which significantly reduced compared with preoperative one (30.81 ±3.63).The difference was statistically significant (t=32.815,P=0.035).The results were excellent in 13 feet,good in 7,and fair in 1,with the excellent and good rate of 95.24％ (20/21).The local infections were cured without recurrence at operative site.Equinus deformities were corrected,and the latest follow-up results showed that all patients walked normally without recurrence.Conclusion Ilizarov method combined with reversed sural and saphenous neurocutaneous island flap can improve the limb function and the flap can survival with good clinical effect.

Objective To investigate the clinical outcomes of combined Ilizarov technique with tendon transfer for the treatment of rigid equinovarus foot deformity.Methods A retrospective analysis was performed on the clinical data of 11 patients (14 feet) with rigid equinovarus foot deformity who were treated by Ilizarov technique combined with tendon transfer without additional bony procedures from August 2015 to February 2018.The average age was 21.6 years old (range,12-36 years old) and 6 patients were males and 5 patients were females.According to Dimeglio classification,8 feet were grade Ⅱ and 6 feet were grade Ⅲ.Seven patients (10 feet) were treated with external fixator and tendon transfer simultaneously.Four patients (4 feet) underwent staging surgery,in which Achilles tendon lengthening,plantar fascia lysis and slow correction of deformity with external fixator were performed as the first stage operation,followed by the second stage tendon transfer.The average interval between the two operations was 26.5 days (range,20-32 days).The lateral tibiotalar angle on load-bearing ankle radiographs and tibiocalcaneal angle on Saltzman view radiographs were measured after operation,and compared with that before operation.Functional evaluation was performed by The American Orthopaedic Foot and Ankle Society (AOFAS) and Ankle Hind foot Scale.Quality of life assessment was assessed by the MOS 36-Item Short Form Health Survey (SF-36) Scale.The excellent and good rate of operation was evaluated by the International Clubfoot Study Group (ICFSG) scoring system.Results All patients were followed up for 6 months to 36 months with an average of 20 months.All cases achieved effective correction.There were no neurovascular complications in this group of patients.The preoperative ankle range of motion in dorsiflexion was-19.9°± 14.8°,and plantar flexion 38.5°± 12.8°.At the latest follow-up,the mean dorsiflexion increased to 2.7°± 1.6° and the plantar flexion decreased to 21.0°±9.2°.Preoperative Dimeglio classification included 8 feet in grade Ⅱ,6 feet in grade Ⅲ.At the latest follow-up,there were 13 feet in grade Ⅰ and 1 foot in grade Ⅱ.The tibiotalar angle was 122.2°± 16.6° before surgery and 100.8°±4.8° at the latest follow-up.The tibiocalcaneal angle of the Saltzman view was-25.2°±9.2° before surgery and-3.7°±2.8° at the latest follow-up.The mean preoperative AOFAS score increased from 63.9± 12.7 to 85.2±9.7,with statistically significant difference (t=14.87,P＜ 0.05).The average SF-36 score increased from 50.1±8.4 to 63.7±8.1,with statistically significant difference (t=4.10,P＜ 0.05).At the latest follow-up,the average ICFSG score was 6.6 (range,3-16).According to the classification of ICFSG score,there were 7 feet excellent,6 feet good,and Ⅰ foot fair,with an excellent and good rate of 92.9％ (13/14).Conclusion Ilizarov technique combined with tendon transfer could achieve successful correction of rigid equinovarus foot deformity with satisfactory short-term results.

Objective:To compare the clinical effect of circular external fixator and intramedullary nail in treatment of tibial segmental fractures.Methods:A retrospective case control study was performed on clinical data of 43 patients with segmental tibial fractures treated from January 2006 to December 2012 in Tianjin Hospital. There were 31 males and 12 females with age range of 20-60 years［（35.9±9.6）years］. All fractures were classified as type 42C2 using the AO/OTA classification. A total of 21 patients treated with circular external fixator（circular fixator group）and 22 patients were treated with intramedullary nail（intramedullary nail group）. The condition of vascular and neural injuries，methods of fracture reduction，time of full weight bearing，bone healing time and infection rate were compared between the two groups. The proximal tibial medial angle，proximal tibial posterior angle，IOWA knee and ankle joint score，range of motion of flexion of keen joint and range of motion of plantar flexion and dorsal flexion of ankle joint were compared between the two groups at the last follow-up.Results:All patients were followed up for 12- 48 months［（19.6±2.1）months］. There were no vascular and neural injuries or other severe complications in both groups. All 21 patients in circular fixator group underwent closed reduction but 3 patients in intramellary nail group were treated by open reduction. The time of full weight bearing was（12.9±2.8）days and in circular fixator group and（75.1±8.0）days in intramedullary nail group（ P<0.05），with bone healing time for（7.0±1.0）months and（8.2±1.4）months，respectively（ P<0.05）. There was no deep infection in both groups. In circular fixator group and intramedullary nail group，the proximal tibial medial angle was（86.7±1.5）° and（93.5±1.7）°（ P<0.05），while the proximal tibial posterior angle was（82.1±1.8）°and（75.1±2.7）°（ P<0.05）. No significant differences were found between the two groups at the last follow-up concerning IOWA knee and joint score，range of motion of flexion of keen joint and range of motion of plantar flexion of ankle joint（ P>0.05）. The range of motion of dorsal flexion of ankle joint in intramedullary nail group was（30.9±3.0）°，better than（21.2±2.2）° in circular fixator group（ P<0.05）. Conclusion:For segmental tibial fractures，cirlular external fixation is superior to intromedullary nail in aspects of completely close reduction，early full weight bearing and early bone healing and alignment.

Treatment of large bone defects and nonunion induced by various causes requires bone graft, and autologous iliac bone graft has always been considered as the gold standard for the treatment of bone transplantation. However, there exist problems such as postoperative pain and numbness in the donor area or insufficient bone taking. The application of reamer-irrigator-aspirator（RIA）technique can reduce complications in the donor area and collect a maximum of 90 ml of autologous bone to treat large bone defects. In addition, it can also be used to remove the infected lesion and residual bone cement in the medullary cavity. The authors review the instrument structure, operation process, clinical application and complications of RIA technique, so as to provide a reference in the treatment of bone defects and intramedullary canal infection.

Objective:To investigate the clinical effects of Ilizarov external fixation combined pedicle flap transfer in the treatment of infected tibial nonunion plus soft tissue defects.Methods:A retrospective study was performed to analyze the data of 35 patients with infected tibial nonunion plus soft tissue defects who had been admitted to Department of Orthopedic Trauma, Tianjin Hospital Affiliated to Tianjin University from July 2005 to July 2020. There were 25 males and 10 females with an age of (37.5±6.0) years. Their original traumas were 27 open and 8 closed fractures, with a disease course ranging from 8 to 42 months. Three patients had undergone 1 operation, 7 patients 2 operations, and 25 patients 3 or more operations. All patients presented with different degrees of skin and soft tissue defects or bone exposure, wound sinus formation and bone scaring. The size of pedicle flaps transferred ranged from 6 cm×5 cm to 15 cm×10 cm. Surgical transfer of skin flap and external fixation were performed at one stage in 25 patients while staged surgery was performed in 10 patients. The first stage consisted of local debridement, vacuum sealing drainage, and delayed flap operation while the second stage consisted of delayed flap transfer and Ilizarov external fixation. The survival of skin flap, limb shortening, bony union and complications were observed after operation. The limb function was evaluated according to the criteria of The Association for the Study and Application of Methods of Ilizarov (ASAMI) for bone and functional results.Results:All patients were followed up for (23.8±7.4) months. Fracture union was achieved in all. The flaps survived postoperatively, the wounds were repaired by the first intention, infection did not recur, and bony union was achieved in 32 patients. Partial necrosis of the flap edge occurred in 3 cases, but responded to dressing change. In the 10 patients undergoing delayed flap operation, 100% of the flaps survived. In all patients, the limbs were shortened by (0.8±0.1) cm, and the tibial fractures got united after (7.2±1.2) months. By the ASAMI criteria for bone results, 29 cases were excellent and 6 cases good; by the ASAMI criteria for functional results, 25 cases were excellent, 8 cases good, and 2 cases fair.Conclusion:As Ilizarov external fixation combined pedicle flap transfer can repair bone and soft-tissue defects at the same time, this surgical scheme facilitates infection control and leads to reliable outcomes.

Objective:To investigate the accuracy and postoperative efficacy of fluoroscopy and CT in measuring the mounting parameters of Taylor Spatial Frame.Methods:Data of patients with peripheral knee deformities who were treated by Taylor Spatial Frame from June 2006 to December 2017 were retrospectively analyzed. According to different measurement methods of mounting parameters, they were divided into fluoroscopy group (mounting parameters were obtained by intraoperative fluoroscopy) and CT group (mounting parameters were obtained by postoperative CT). There were 33 patients (35 segments) in the fluoroscopy group, 23 males (23 segments) and 10 females (12 segments), with an average age of 36.4±11.6 years old. In CT group, there were 30 patients, 19 males and 11 females, with an average age of 36.9±13.8 years. There were 22 cases (24 segments) of high tibial osteotomy, 5 cases (5 segments) of distal femur osteotomy, and 6 cases (6 segments) of both distal femur and high tibial osteotomy. Operation time, external fixation time, the number of electronic prescription and deformity correction time, mechanical axis deviation (MAD), medial proximal tibia angle (MPTA), mechanical lateral distal femoral angle (mLDFA), range of motion (ROM) andhospital for special surgery (HSS) knee functional scores were compared between the two groups.Results:All the 63 patients were followed up for 21.9 months (range, 12-60 months). In fluoroscopy group, operating time was 100.9±9.1 min, electronic prescription number 1.4±0.6, and deformity correction time was 19.4±3.6 days. In CT group, operating time was 79.2±10.8 min, electronic prescription number 1.2±0.4, and deformity correction time was 16.0±4.4 days. The difference of the above indexes between the two groups was statistically significant ( t=8.803, 2.042, 3.440, all P < 0.05). In the fluoroscopy group, the external fixation time was 4.8±0.9 months; MAD was 4.3±2.1 mm; MPTA was 88.5°±1.9°; mLDFA was knee 89.2°; ROM was 122.4°±3.9° and HSS score was 90.0±3.6. In CT group, the external fixation time was 4.6±0.9 months; MAD was 4.0±1.9 mm; MPTA was 87.8°±1.7°; mLDFA was knee 88.6°; ROM was 122.7°±3.4° and HSS score was 91.1±2.9. There was no statistically significant difference in the above indexes between the two groups (all P >0.05). In the fluoroscopy group, 22 segmental deformities were corrected by one electronic prescription, and 13 segmental deformities were corrected by two or more electronic prescriptions. In CT group, 25 segmental deformities were corrected by one electronic prescription, and 5 segmental deformities were corrected by two electronic prescriptions. There was no incision infection and no neurovascular injury in the two groups. Conclusion:Both fluoroscopy and CT scan can obtain the mounting parameters of the Taylor Spatial Frame, and the results of correction of the peripheral deformities of the knee joint are satisfactory. However, CT measurement of the mounting parameters is more accurate which could achieve shorter operation time, and less times of electronic prescriptions.

Objective:To compare the biomechanical properties of different circular external fixators for the fracture site of oblique long bone fractures.Methods:15 polyethylene (PE) plastic rods with the same batch were selected to make the model of oblique fractures in the middle of long bones. According to the connection between PE rods and external fixators, the PE rods were randomly divided into: the group that was simply used kirschner wires (group kirschner wires), the group that was simply used olive wires (group olive wires), the group that was simply inserted half pins (group half pins), the group that was inserted single cortical fixed half pins at either side of the fracture site after being fixed by the tensioned olive wires (group olive wires+ half pin), the group that was inserted tensioned trans-fracture olive wires after being fixed by the tensioned olive wires (group olive wires+ olive wires). The axial compression tests were carried out, and the interfragmentary displacements under axial loads of 200 N, 400 N, 600 N and 800 N were measured and the axial stiffness was calculated. Then, the torsional tests were carried out, and the interfragmentary torsional angles were measured under torsional loads of 4 N·m, 7 N·m and 10 N·m, and the torsional stiffness was calculated.Results:With the increase of axial load from 200 N to 800 N, the axial interfragmentary displacement in each group gradually increased. The interfragmentary axial displacement of each group in ascending order was: group olive wires+ olive wires, group olive wires+ half pins, group half pins, group olive wires, group kirschner wires. The axial stiffness of each configuration under 800 N axial load in descending order was: group olive wires+ olive wires [863.93 (824.32, 875.87) N/mm], group olive wires+ half pins [119.92 (113.16, 123.58) N/mm], group half pins [81.92(79.42, 82.40) N/mm], group olive wires [76.83 (72.45,79.47) N/mm], group kirschner wires [70.80 (67.49, 71.59) N/mm]. The pairwise comparisons of the axial stiffness data of each configuration had statistical significance (all P <0.05). With the increase of the torque load from 4 N·m to 10 N·m, the interfragmentary rotational angle in each configuration gradually increased. The interfragmentary torsion angle of each group in ascending order was: group half pins, group olive wires+ olive wires, group olive wires+ half pins, group olive wires, group kirschner wires. The torsional rigidity of each configuration under 10 N·m torsional load in descending order was: group half pins [1.80 (1.63, 1.85) N·m/°], group olive wires+ olive wires [1.05 (1.02, 1.07) N·m/°], group olive wires+ half pins [0.99 (0.98, 1.03) N·m/°], group olive wires [0.81 (0.78, 0.82) N·m/°], group kirschner wires [0.75 (0.74, 0.76) N·m/°]. The pairwise comparisons of the torsional rigidity data of each configuration had statistical significance (all P < 0.05). Conclusion:The axial stiffness and torsional stiffness of circular external fixators can be increased by using tensioned olive wires or half pins at the fracture site. Due to the insufficient support between oblique fracture site, when the load is applied, the axial displacement and torsion angle of the fracture site will still be fairly large after being fixed the fracture site with half pins. Treating with tensioned trans-fracture olive wires after being fixed by the tensioned olive wires at either side of the fracture site can effectively control the interfragmentary shear and displacement, thus providing an ideal mechanical environment for fracture healing.

Objective To evaluate the clinical outcomes and correction accuracy of deformities around the knee joint using external fixator-assisted internal fixation (FAIF).Methods From January 2014 to March 2018,data of 15 patients (17 bone segments) with deformities around the knee joint who had been corrected with external fixator-assisted internal fixation were retrospectively analyzed.There were 6 males and 9 females,with an average age of 39 years (range,21-60 years).There were 9 patients with genu varus and 6 with genu valgus.All the 15 patients had shortening ranging from 5 to 22 mm,with an average of 12 mm.Unilateral external fixator was used to stabilize the osteotomy site intraoperatively until the satisfied mechanical axis was acquired.Then the plate or Intramedullary nail was inserted and fixed,the external fixator was removed after internal fixation.Results Femur osteotomy was done in 7 patients and tibia osteotomy was done in 6 patients,while 2 patients had osteotomy in both tibia and femur.Intramedullary nailing was used in 2 bone segments,and plate was used in 15 bone segments.The correction of angle ranged from 7° to 22°,with an average of 12.5°.The correction of the 9 cases of genua varus ranged from 10° to 22°,with an average of 17.6°.The correction of the 6 cases of genu valgum ranged from 7° to 13°,with an average of 10.4°.The mean time to achieve union of the osteotomy sites was 3.5 months (range,2.5-5.0 months).All the 15 patients were followed up for 8-48 months (average,23 months).The mechanical axis deviation (MAD) was 5.93 mm (range,0-15 mm) after operation which was 34.8 mm (range,8-55 mm) before operation.The mean post-operative mechanical lateral distal femoral angle (mLDFA) was 87.5° (range,84°-90°) which was 76.1° (range,66°-82°) before operation.The mean medial proximal tibia angle (MPTA) was 87.8° (range,86°-89°) which was 76.8° (range,68°-80°) before operation.There were no deep infection and neurovascular injury.Conclusion The FAIF not only has the advantage of minimal invasiveness and easy adjustment,but also can avoid uncomfortableness and complications of long-term of wearing the external fixator.It is an accurate and safe method to correct the deformities around the knee joint.