Objective To summarize the progress of Masquelet technique to repair bone defect. Methods The recent literature concerning the application of Masquelet technique to repair bone defect was extensively reviewed and summarized. Results Masquelet technique involves a two-step procedure. First, bone cement is used to fill the bone defect after a thorough debridement, and an induced membrane structure surrounding the spacer formed; then the bone cement is removed after 6-8 weeks, and rich cancellous bone is implanted into the induced membrane. Massive cortical bone defect is repaired by new bone forming and consolidation. Experiments show that the induced membrane has vascular system and is also rich in vascular endothelial growth factor, transforming growth factor β1, bone morphogenetic protein 2, and bone progenitor cells, so it has osteoinductive property; satisfactory results have been achieved in clinical application of almost all parts of defects, various types of bone defect and massive defect up to 25 cm long. Compared with other repair methods, Masquelet technique has the advantages of reliable effect, easy to operate, few complications, low requirements for recipient site, and wide application. Conclusion Masquelet technique is an effective method to repair bone defect and is suitable for various types of bone defect, especially for bone defects caused by infection and tumor resection.
ObjectiveTo summarize the research progress of difficulty in removing of locking plate and screw. MethodsThe domestic and foreign related literature about difficulty in removing of locking plate and screw was reviewed. The incidence, the reason, preventive measure, removing method, and its advantages and disadvantages were summarized and analyzed. ResultsWith the popularization of locking plate application, cases with difficulty in removing locking screw have significantly increased compared with non-locking plate, so it has become a new clinical problem. The main reasons are stripping, cross-threading, and cold-welding. In recent years, for the difficulty in removing of locking plate and screw, some special extraction tools and new extraction methods have developed, but each has its defects and indications. ConclusionSufficient preoperative preparation, being familiar with its advantage and disadvantage as well as its indications are necessary. The specific situations of patient, including the reason, the screw, the plate, the incision, the bone quantity, and existing equipment, should be comprehensively considered to select appropriate methods.
ObjectiveTo compare the effectiveness of percutaneous compression plate (PCCP) and hollow compression screw in the treatment of displaced femoral neck fractures. MethodsBetween January 2010 and June 2014, 70 patients with displaced femoral neck fractures were randomly divided into 2 groups. After reduction, fracture was fixed with PCCP in 35 cases (group A) and with hollow compression screw in 35 cases (group B). There was no significant difference in the gender, age, cause, side and type of fractures, time from injury to operation, associated disease, pre-operative Harris score and visual analogue scale (VAS) score between 2 groups (P > 0.05). The operation time, intra-operative blood loss, fracture healing time, fracture reduction quality, time of rehabilitation and weightloading; complication, post-operative Harris score and post-operative VAS score were compared between 2 groups. ResultsThe incisions healed by first intention. All patients were followed up 13-34 months (mean, 23.7 months). There were significant differences in operation time, intra-operative blood loss, and fracture healing time between 2 groups (P < 0.05). There was no significant in the fracture reduction quality between 2 groups (P > 0.05). Avascular necrosis of the femoral head occurred in 2 cases of group A after operation (fracture reduction quality: grade IV); and avascular necrosis of the femoral head occurred in 4 cases of group B after operation (fracture reduction quality: grade I in 2 cases, grade Ⅱ in 1 case, grade Ⅲ in 1 case, and grade IV in 1 case), nonunion in 1 case, and screw loosening in 3 cases; and there was significant difference in the incidence of bone nonunion and avascular necrosis of the femoral head between 2 groups (χ2=-3.997, P=0.046). Difference was significant in fracture reduction quality in the patients with avascular necrosis of the femoral head and nonunion between 2 groups (χ2=1.991, P=0.047). The time of rehabilitation and weight-loading of group A was significantly earlier than that of group B (P < 0.05); the Harris and VAS scores of group A were significantly better than those of group B at 12 months after operation (P < 0.05). ConclusionPCCP for treatment of displaced femoral neck fractures has better static stability and better sliding dynamic pressure effect than hollow compression screw, and it can provide earlier rehabilitation and weight-loading postoperatively and obviously decrease the incidence of bone nonunion and avascular necrosis of the femoral head, but avascular necrosis of the femoral head still occur in patients with poor reduction or comminuted fracture.
ObjectiveTo investigate the causes of spontaneous osteogenesis of Masquelet technique induced membrane. MethodsForty-two male Sprague-Dawley rats aged 7-9 weeks were selected to establish a critical-sized bone defect of the right middle femur model. Then the rats were randomly divided into 4 groups, with 12 rats in groups A-C and 6 rats in group D. The bone defects in groups A-C were filled with vancomycin-loaded polymethyl methacrylate bone cement spacers. Then the Kirschner wires were used for intramedullary fixation in groups A and B, and the bone cement was used to connect the bone cement spacers and the bone ends in group B. The steel plate was used to fixation in group C. The bone defect in group D was only fixed with steel plate as a blank control group. The general condition was observed after operation. At 5 weeks after operation, 6 rats in groups A-C were selected for STRO-1 immunohistochemical staining to observe the content of mesenchyme stem cells (MSCs) in the induced membrane (STRO-1+ cells). At 12 weeks after operation, the remaining rats in groups A-D were taken for X-ray observation, gross observation, and histological observation (HE, safranin O-green staining) to observe the spontaneous osteogenesis of the membrane.Results All rats in the 4 groups survived until the completion of the experiment. At 5 weeks after operation, the immunohistochemical staining showed that group B was negative, while the contents of MSCs in the induced membrane in groups A and C were 14.20%±1.92% and 5.00%±0.71%, respectively, with a significant difference (P<0.05). At 12 weeks after operation, group A showed that the new bone formed at the osteotomy site and growth towards the center of the bone defect, with an average length of 3.1 mm on one side; and the presence of bone, cartilage lesions, fibers, and a small amount of neovascularization were observed in the induced membrane. Group C only had a small amount of new bone at the osteotomy site, and a small amount of neovascularization in the induced membrane. Groups B and D did not have any new bone, but bone resorption or atrophy at the osteotomy site. ConclusionAlthough the Masquelet technique induced membrane has osteogenesis, the key factor for the spontaneous osteogenesis is the bone marrow overflow from the bone marrow cavity providing MSCs. The spontaneous osteogenesis of the induced membrane belongs to endochondral ossification.
ObjectiveTo investigate the countermeasures for difficult removal of screws in the plate. MethodsThe clinical data were retrospectively analyzed from 47 patients having difficult removal of screws in the plate between January 2004 and May 2014. There were 30 males and 17 females, aged 16-58 years (mean, 34 years). The time from internal fixation to removal of internal fixation was 10 months to 20 years (mean, 22 months). The locations of internal fixation were upper extremity in 25 cases and lower extremity in 22 cases. The number of difficult removal screws in the plate was 1 in 18 cases, 2 in 15 cases, 3 in 9 cases, and 4 in 5 cases. The plate types included general plate in 15 cases and locking plate in 32 cases; stainless steel plate in 10 cases and titanium plate in 37 cases. The reason for difficult removal, plate, screw, incision, and bone quality of patient were comprehensively analyzed, and different methods for difficult removal were chosen according to the principle that first simply then complicated. ResultsAll plates and screws were removed, and no iatrogenic fracture or nerve and vascular injuries occurred. The operation time was 65-270 minutes (mean, 125 minutes). The blood loss was 80-775 mL (mean, 157 mL). The postoperative drainage was 20-250 mL (mean, 92 mL). The incision healing by first intention was obtained in 39 cases, and delayed healing in 8 cases. The patients were followed up 3-24 months (mean, 10 months). No infection or re-fracture was observed. ConclusionThere are many countermeasures for difficult removal of screws in the plate, but each has indication. As long as a well arranged preoperative condition, mastering a variety of methods, and being familiar with its indication, as well as reasonably choosing method based on the specific situations, the plate and screw maybe smoothly removed.
ObjectiveTo summarize the research progress in the treatment of fractures by far cortical locking technique. MethodThe domestic and foreign related literature about the treatment of fractures by far cortical locking technique was reviewed, summarized, and analyzed. ResultsIn order to overcome the shortcomings of high stress at the near side of the plate and high stiffness of traditional locking plate, a new far cortical locking technique has been developed recently. The structure retains the overall strength of locking plate, but decreases the stiffness of the fixation by 80%, so it can provide interfragmentary parallel micromotion and help to form symmetric callus, and satisfactory results have been achieved in theory, experiment, and clinical application of treatment of fractures by far cortical locking. ConclusionsThe far cortical locking technique is a major improvement of locking plate, which is expected to significantly reduce delayed healing and nonunion of some fractures treated with traditional locking plate.
ObjectiveTo explore the differences in the implantation safety and stability of a S1 alar-iliac screw (S1AIS) or S2AIS for sacroiliac joint fixation, providing reference for selecting appropriate internal fixation in clinical practice. MethodsPatients who underwent pelvic CT examination between January 2024 and December 2024 were selected. CT data from 80 patients with normal pelvic structure who met the selection criteria were included in a 1:1 male to female ratio. CT digital reconstruction technology was used to measure the transverse and longitudinal diameters of the S1AIS and S2AIS insertable ranges, as well as the length, width, and sacral side length of the screw trajectory. The pelvic CT data from 30 patients were randomly selected based on a 1:1 male to female ratio for three-dimensional (3D) printing of pelvic samples. The S1AIS/S2AIS with a diameter of 6.5 mm and 8.0 mm were implanted at the optimal entry/exit points on the left and right sides, respectively, to observe the perforation of the screw trajectory. The pelvic CT data from 1 patient was randomly selected for 3D printing of 10 pelvic samples to simulate Tile C2 fracture. They were divided into S1AIS group (n=5) and S2AIS group (n=5), with one S1AIS and one S2AIS fixation used for posterior sacroiliac joint separation, and the specimen stiffness and maximum load were measured by using an electric tension torsion dual axis universal mechanical tester. ResultsThe anatomical parameter measurement showed that there was no significant difference in the length and width of the screw trajectory between S1AIS and S2AIS (P>0.05), but the transverse and longitudinal diameters of the insertable ranges, as well as the sacral side length of the screw trajectory, were all greater than those of S2AIS, with significant differences (P<0.05). After simulating the implantation of S1AIS and S2AIS with a diameter of 6.5 mm in pelvic specimens, no screw penetration was observed. Both S1AIS and S2AIS with a diameter of 8.0 mm showed screw penetration, with S2AIS having a higher incidence of posterior lateral sacral cortical penetration (46.7%) than S1AIS (3.3%) (P<0.05). The biomechanical test showed that the stiffness and maximum load of S2AIS were significantly lower than those of S1AIS (P<0.05). ConclusionAs a method to fix the sacroiliac joint, the S1AIS has a larger insertable range, a longer sacral side length of the screw trajectory, a lower incidence of posterior lateral cortical rupture of the sacrum, and a greater fixation strength than S2AIS. Therefore, the implantation safety and fixation stability of the S1AIS are superior to S2AIS, and a diameter less than 8.0 mm screws should be selected as S2AIS for Chinese people.