BACKGROUND:With the development of stem cellresearch and regenerative medicine, a growing number of technique applications of bone marrow mesenchymal stem cells have been used for treatment of femoral head necrosis. Simple grafting and injection of bone marrow mesenchymal stem cells has a poor effect, which is combined with scaffold materials as cells carrier plays a better role.
OBJECTIVE:To review the research progress of bone marrow mesenchymal stem cells and carriers in the treatment of femoral head necrosis and to look into the future development prospects.
METHODS:A computer-based online search of PubMed (1989/2013) and CNKI (1989/2013) was performed for articles with the key words“osteonecrosis of the femoral head, avascularnecrosis, bone marrow mesenchymal stem cells, carrier or scaffold material”in English and Chinese, respectively. The advantages and limits of various carries and scaffolds were summarized.
RESULTS AND CONCLUSION:Ideal carriers can promote and induce ability of bone marrow mesenchymal stem cells to repair the femoral head. There is a variety of existing carriers, including autologous cancellous bone, al ograft bone, natural biological materials, organic materials, bio-ceramic, nano-materials. Since each material has its own advantages and limitations, composite materials have begun to be used in searching for ideal carriers and scaffolds, and there are however stil some issues that remain to be solved, such as lacking of unified standard of production, specification and making process;how to control and prevent the immune response and inflammation after implantation;how to ensure that the degradation rate of scaffold matches the generation rate of bone and cartilage in the femoral head;and how to identify the cytotoxicity, biocompatibility and therapeutic effects after implantation.

Objective:To evaluate the clinical efficacy of percutaneous channel screwing assisted by the robot navigation positioning system combined with pelvic unlocking reduction frame for pelvic fractures.Methods:A retrospective analysis was conducted of the 12 patients with pelvic fracture who had been admitted to Department of Orthopaedics, The First Affiliated Hospital to Anhui Medical University from January to October 2018. They were 7 men and 5 women with an average age of 42.3 years (from 25 to 62 years). The time from injury to operation averaged 5.1 days (from 2 to 10 days). There were 2 cases of type B1, 5 ones of type B2 and 5 ones of type C1 according to the Tile classification. After closed reduction using the pelvic unlocking reduction frame, the orthopedics robot navigation positioning system was used to guide the placement of percutaneous screws. The posterior rings were fixated with sacroiliac screws, and the anterior rings with pubis screws, pubic symphysis screws or external fixation. The placement time for each screw, fluoroscopy frequency, reduction quality, fracture union time, function of the affected hip and complications at the final follow-up were recorded.Results:A total of 25 percutaneous screws were inserted in the 12 patients with a mean fluoroscopic frequency of 4.7 times (from 3 to 8 times) and a mean placement time of 14.9 min (from 12 to 20 min). According to the Matta rating system, the fracture reduction was rated as excellent in 7 cases, as good in 4 and as fair in one. The average follow-up time was 11.3 months (from 6 to 16 months). All fractures healed after an average period of 11.8 weeks (from 10 to 14 weeks). By the Majeed scoring, the pelvic function at the final follow-up was excellent in 8 cases and good in 4. The follow-ups observed no infection, nerve injury, deep vein thrombosis, heterotopic ossification, implant looseningor traumatic arthritis in these patients.Conclusion:Percutaneous channel screwing assisted by the robot navigation positioning system combined with pelvic unlocking reduction frame can reduce operative time and risks and lead to minimal invasion for pelvic fractures.

Objective:To investigate the effect of Ilizarov bone transport technique combined with vancomycin bone cement for treatment of posttraumatic tibial bone infection combined with bone and soft tissue defects.Methods:A retrospective case series study was performed on 11 patients with posttraumatic tibial bone infection combined with bone and soft tissue defects admitted to First Affiliated Hospital of Anhui Medical University from June 2016 to June 2019.There were 7 males and 4 females, with age of 21-56 years [(41.5±12.1)years]. After debridement, the length of bone defect was 4-13.2 cm [(8.1±2.6)cm], and the area of soft tissue defect was 6.5-23.4 cm 2 [(16.2±4.7)cm 2]. All patients were treated firstly with debridement of bone infection and vancomycin loaded bone cement pad filling, followed by Ilizarov technique to repair bone and soft tissue defects. The soft tissue docking time, fracture docking time, external fixation time and external fixation index were recorded. At the last follow-up, Johner wruhs score was used to evaluate the curative effect and American Orthopedic Foot and Ankle Society (AOFAS) ankle hindfoot score to evaluate the ankle joint function. The postoperative complications were observed. Results:All patients were followed up for 17-23 months [(17.9±4.5)months]. The soft tissue docking time was 48-155 days [(101.7±29.0)days] and fracture docking time was 55-167 days [(111.6±29.5)days]. The external fixation time was 154-450 days [(322.9±86.3)days] with an external fixation index of 31.1-61.5 cm/day [(40.8+ 7.5)cm/day]. At the last follow-up, the results were excellent in 2 patients, good in 4 and fair in 5 based on Johner-Wruhs score. At the last follow-up, the AOFAS ankle hindfoot score was 61-94 points [(76.6±12.7)points], with excellent results in 3 patients, good in 2 and fair in 6. Four patients were treated with secondary operation, and two of them bad docking site nonunion which healed after secondary bone grafting. No free or local transposition flap repair was performed in regardless of soft tissue defect. During the follow-up, there were no complications such as fever, wound weeping, soft tissue necrosis or neurovascular injury.Conclusion:For posttraumatic tibial bone infection combined with bone and soft tissue defects, the Ilizarov bone transport technique combined with vancomycin-loaded bone cement has advantage of shorter operation time, trauma and complications, and can achieve bone lengthening and soft tissue healing simultaneously.

Objective:To explore the effects of multimodal imaging on the performance of automatic segmentation of glioblastoma targets for radiotherapy based on a deep learning approach.Methods:The computed tomography (CT) images and the contrast-enhanced T1 weighted (T1C) sequence and the T2 fluid attenuated inversion recovery (T2- FLAIR) sequence of magnetic resonance imaging (MRI) of 30 patients with glioblastoma were collected. The gross tumor volumes (GTV) and their corresponding clinical target volumes CTV1 and CTV2 of the 30 patients were manually delineated according to the criteria of the Radiation Therapy Oncology Group (RTOG). Moreover, four different datasets were designed, namely a unimodal CT dataset (only containing the CT sequences of 30 cases), a multimodal CT-T1C dataset (containing the CT and T1C sequences of 30 cases), a multimodal CT-T2-FLAIR dataset (containing the CT and T2- FLAIR sequences of the 30 cases), and a trimodal CT-MRI dataset (containing the CT, T1C, and T2- FLAIR sequences of 30 cases). For each dataset, the data of 25 cases were used for training the modified 3D U-Net model, while the data of the rest five cases were used for testing. Furthermore, this study evaluated the segmentation performance of the GTV, CTV1, and CTV2 of the testing cases obtained using the 3D U-Net model according to the indices including Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and relative volume error (RVE).Results:The best automatic segmentation result of GTV were achieved using the CT-MRI dataset. Compared with the segmentation result using the CT dataset (DSC: 0.94 vs. 0.79, HD95: 2.09 mm vs. 12.33 mm, and RVE: 1.16% vs. 20.14%), there were statistically significant differences in DSC ( t=3.78, P<0.05) and HD95 ( t=4.07, P<0.05) obtained using the CT-MRI dataset. Highly consistent automatic segmentation result of CTV1 and CTV2 were also achieved using the CT-MRI dataset (DSC: 0.90 vs. 0.91, HD95: 3.78 mm vs. 2.41 mm, RVE: 3.61% vs. 5.35%). However, compared to the CT dataset, there were no statistically significant differences in DSC and HD95 of CTV1 and CTV2 ( P>0.05). Additionally, the 3D U-Net model yielded some errors in predicting the upper and lower bounds of GTV and the adjacent organs (e.g., the brainstem and eyeball) of CTV2. Conclusions:The modified 3D U-Net model based on the multimodal CT-MRI dataset can achieve better segmentation result of glioblastoma targets and its application potentially benefits clinical practice.

OBJECTIVE: To explore the reduction and support effect of the subchondral screw compression technique for residual or secondary collapse of the lateral tibial plateau during operation. METHODS: Between January 2020 and June 2021, 11 patients with residual or secondary collapse of the lateral tibial plateau during operation were treated with the subchondral screw compression technique. There were 6 males and 5 females, aged 52.3 years old (range, 27-64 years). The fractures were caused by traffic accident in 10 cases and falling from height in 1 case and located at the left knee in 6 cases and the right knee in 5 cases. According to Schatzker classification, there were 5 cases of type Ⅱ fractures, 4 cases of type Ⅲ fractures, and 2 cases of type Ⅴfractures. According to the three columns classification, there were 5 cases of lateral column, 4 cases of lateral column and posterior column, and 2 cases of three columns. The time from injury to operation was 4.5 days (range, 3-7 days). During the follow-up, X-ray films were obtained and the Rasmussen standard was used to evaluate the quality of fracture reduction, meanwhile fracture healing was observed. The medial proximal tibial angle (mPTA), posterior tibial slope angle (pTSA), and articular surface collapse were measured at immediate and 12 months after operation. The knee joint range of motion was evaluated at last follow-up, and the knee joint function was evaluated using the Hospital for Special Surgery (HSS) score. RESULTS: All operations were successfully completed, with a mean operation time of 71.4 minutes (range, 55-120 minutes), and a mean hospital stay of 8.0 days (range, 5-13 days). The incisions all healed by first intention, without complications such as infection, flap necrosis, or vascular and nerve injury. All patients were followed up 16.5 months on average (range, 12-24 months). X-ray films showed that the fracture reduction score was 14-18 (mean, 16.7) according to Rasmussen score criteria; and 5 cases were rated as excellent and 6 as good. All fractures healed clinically with a mean clinical healing time of 14.9 weeks (range, 12-16 weeks), and there was no complications such as plate or screw loosening. At 12 months after operation, the mPTA and pTSA were (87.5±1.7)° and (6.2±3.1)°, respectively; there was no significant difference when compared to the values at immediate after operation [(87.6±1.8)° and (6.5±3.1)°] ( P>0.05). The articular surface of the tibial plateaus was effectively supported, and it collapsed again by 0-1.0 mm at 12 months, with an average of 0.4 mm. At last follow-up, the knee joint range of motion was 115°-135° (mean, 126.8°) and the HSS score for knee joint function was 87-98 (mean, 93.9). Five patients underwent secondary operation to remove the internal fixator at 12-18 months after operation. CONCLUSION The subchondral screw compression technique is helpful for the reduction of residual or secondary collapse of the lateral tibial plateau during operation, and can provide good support for osteochondral blocks.
Male ; Female ; Humans ; Middle Aged ; Tibial Fractures/complications* ; Fracture Fixation, Internal/methods* ; Treatment Outcome ; Knee Joint/surgery* ; Bone Screws ; Retrospective Studies