Patient-Derived Tumor Xenografts Plus Ex Vivo Models Enable Drug Validation for Tenosynovial Giant Cell Tumors.

INTRODUCTION: Tenosynovial giant cell tumor (TGCT) is a locally aggressive tumor with colony-stimulating factor 1 receptor (CSF1R) signal expression. However, there is a lack of better in vivo and ex vivo models for TGCT. This study aims to establish a favorable preclinical translational platform, which would enable the validation of efficient and personalized therapeutic candidates for TGCT. PATIENTS AND METHODS: Histological analyses were performed for the included patients. Fresh TGCT tumors were collected and sliced into 1.0-3.0 mm3 sections using a sterilized razor blade. The tumor grafts were surgically implanted into subrenal capsules of athymic mice to establish patient-derived tumor xenograft (PDTX) mouse models. Histological and response patterns to CSF1R inhibitors evaluations were analyzed. In addition, ex vivo cultures of patient-derived explants (PDEs) with endpoint analysis were used to validate TGCT graft response patterns to CSF1R inhibitors. RESULTS: The TGCT tumor grafts that were implanted into athymic mice subrenal capsules maintained their original morphological and histological features. The "take" rate of this model was 95% (19/20). Administration of CSF1R inhibitors (PLX3397, and a novel candidate, WXFL11420306) to TGCT-PDTX mice was shown to reduce tumor size while inducing intratumoral apoptosis. In addition, the CSF1R inhibitors suppressed circulating nonspecific monocyte levels and CD163-positive cells within tumors. These response patterns of engrafts to PDTX were validated by ex vivo PDE cultures. CONCLUSIONS: Subrenal capsule supports the growth of TGCT tumor grafts, maintaining their original morphology and histology. This TGCT-PDTX model plus ex vivo explant cultures is a potential preclinical translational platform for locally aggressive tumors, such as TGCT.

Efficacy and safety of recombinant human epidermal growth factor for diabetic foot ulcers: A systematic review and meta-analysis of randomised controlled trials.

To evaluate the efficacy and safety of recombinant human epidermal growth factor (rhEGF) in treating diabetic foot ulcers (DFUs), we conducted both database searches (PubMed, MEDLINE, EMBASE, CENTRAL, and Web of Science) and reference searches for randomised controlled trials from the inception of databases to 30 January 2020. Two reviewers independently scrutinised the trials, extracted data, and assessed the quality of trials. The primary outcome was the proportion of complete healing. The secondary outcomes were mean time to complete healing and adverse events. A subgroup analysis was performed by different administration routes. Statistical analyses were performed in RevMan 5.3. The time to complete healing Kaplan-Meier curves was pooled in the R software. Of the 156 citations, 9 trials (720 participants) met eligibility criteria and were included. The rhEGF achieved a higher complete healing rate than placebo (OR: 2.79, [95% CI: 1.99, 3.99]). The rhEGF also significantly shorten complete healing time (MD: -14.10 days, [95% CI: -18.03, -10.16]). Subgroup analysis showed that topical application was superior to intralesional injection, but that may be because of different ulcer severity they included. No significant difference was shown in adverse events. Results were coherent with sensitivity analyses. Therefore, rhEGF is an effective and safe treatment for DFUs.

[Therapeutic Effect of Uncemented Allograft-prosthetic Composite for the Reconstruction of Tumorous Bone Defect].

OBJECTIVE: To investigate the surgical techniques and mid-term efficacy of reconstruction for proximal femur with allograft-prosthetic composite (APC) . METHODS: Fifteen patients who underwent uncemented APC reconstruction of proximal femur after bone tumor resection were retrospectively evaluated. Image and physical examinations were taken on the 1st,3rd,6th,9th and 12th month after surgery and every 6 months thereafter to assess union condition,greater trochanteric bone absorption and myodynamia of abductors. Musculoskeletal Tumor Society (MSTS) and Harris Hip Score (HHS) were utilized to evaluate the function of hip joint. RESULTS: Seven male and eight female patients were included with average age of 25.1 years(17-56 years) and average followup of 32.8 months(18-48 months). Four patients had giant cell tumor of the bone,3 patients had osteosarcoma,3 patients had chondrosarcoma,2 patients had malignant fibrous histiotoma,2 patients had osteoblastoma and 1 patient had Ewing sarcoma. Unions occurred in the allograft-host bone interfaces of all patients in the period of 5-9 months postoperatively. Bone absorption in the allograft-host bone interfaces,dislocation,hypersensitivity of the allograft and acetabulum abrasion were not observed,while there were no metastasis and tumor recurrence. Three patients had periprosthetic fractures intraoperatively and were well fixed with cerclage. Absorptions in the greater trochanteric happened to 6 patients. All patients had mean MSTS and HHS scores of 11.3 (7-15) and 47.3 (40.3-58.5) preoperatively and 26.1(24-29) and 80.1(66.2-92.7) postoperatively. CONCLUSION: Uncemented APC reconstruction is proper for young patients with long life expectancy and high demand of function that suffered from tumors of proximal femur.

[Design of Minimal Invasive Screw on Posterior Pelvis Ring and Pelvic Finite Element Analysis].

OBJECTIVE: To design minimal invasive screw on posterior pelvic ring and perform threedimensional finite element analysis based on a pelvis finite element model. METHODS: We measured the pelvic anatomical data of 20 healthy volunteers and identified potential designs for minimal invasive screw on posterior pelvic ring. A finite element model of pelvis was then established. Threedimensional finite element analyses were performed under static and dynamic mechanical loading,respectively. RESULTS: Three screw tracks on ilium (A,B and C) were identified based on a threedimensional reconstruction of pelvis. Nail track B and C had greater length and width,but shorter distance between nailing and soft tissue compared with nail track A. Static loading under an external rotation load of 500 N generated a maximum Mises Von stress of 582.05 Pa and sacral iliac complex of 107.38 Pa. The greatest strain was located at the articular cartilage on the side of the nail,followed by lateral sacral joint cartilage and symphysis pubis. The largest displacement was located at the ilium on the side of the nail,with a gradient decrease to the opposite side. The largest displacement of the anterior superior iliac spine was 0.35 cm on the side of the nail. The dynamic loading identified displacement of the anterior superior iliac spine with 1.5 mm in Z axis,1.8 mm in X axis and -0.2 mm in Y axis; and displacement of the pubic bone with 0.8 mm in Z axis,1.0 mm in X axis and 0.03 mm in Y axis. The maximum displacement appeared along the impact direction: Y axis. Relatively large equivalent stress was found in pubis and ischium,anterior superior iliac spine,sacrum,acetabular that are prone to fracture. With increased impact force,the stress of pelvis increased over time. The maximum impact force,stress and displacement of the pelvis occurred at 10 ms when peak force was reached. Under the impact of 4 000 N and 5 000 N,the bone was subject to a stress level of over 200 MPa,exceeding its average yield strength,which suggests a possibility of pelvic fracture. CONCLUSION: Taking B/C as a main screw track and A as an auxiliary screw track is a reasonable choice. The pelvic finite element model lays a foundation for further studies into sacral fracture and design of screw tracks.

[Extensively Porous-coated Distal Fixation Long Stem Prosthesis for Unstable Proximal Femur Fracture with Complex Hip Disease].

OBJECTIVES: To evaluate the clinical results of femoral proximal fracture with complex hip diseases using an uncemented extensively porous-coated long femoral stems. METHODS: 15 cases of femoral proximal fracture with complex hip diseases treated with the uncemented extensively porous-coated long femoral stem were retrospectively reviewed. All patients were followed up at 1, 3, 6, 12 months in the first year postoperatively and once a year from the second year on.Radiological evaluations were conducted using the related criteria, including anteropostierior radiograph of pelvis, anteropostierior and lateral radiograph of proximal femur, and flat tomography of lower limbs.The bone union of the femur fracture, the fixation of prosthesis, and periprosthetic bone loss were evaluated by above-mentioned radiography.The subsidence of femoral prosthesis was compared between 1 month postoperatively and the last follow-up. Complications during the follow-up period was recorded.Clinical outcomes were assessed with Harris Hip Score the last follow-up, including excellent (90-100), good (80-89), moderate (70-79) and bad (<70). RESULTS: The average follow-up period was (45.5±21.7) months. All fractures were united at mean 12.6 weeks. There were no femoral stem subsidence and evidence of loosening both radiologically and clinically. The reconstructive offset for femoral fracture was 35.8 mm, while the contralateral offset was 34.8 mm. The average Harris Hip Score was 89.5 at the last follow-up. Moreover, no loosening, dislocation or infection were observed. CONCLUSIONS: Total hip arthroplasty with extensively porous-coated long femoral stem provides a good fracture stability that promotes fracture healing and offers a successful solution for femoral proximal fracture with complex hip diseases.

[Clinical Significance of Hip Rotation Center Location after Reconstruction with Modular Hemipelvic Prostheses for Pelvic Tumor].

OBJECTIVE: To investigatethe clinical significance of hip rotation center location after reconstruction with modular hemipelvic prostheses for periacetabula tumors. METHODS: Forty-two patients who received periacetabular tumor resection and reconstruction with modular hemipelvic prosthesis between January 2004 and January 2014 in our institute were included. Postoperative complications, function (measured by MSTS score), survival rate and recurrence rate were analyzed. The position of prosthetic hip rotation center was measured. By its deviation angle from the ideal rotation center, the patients were divided into inward group, normal group and outward group in the horizontal level, and upward group, normal group and downward group in the vertical direction. And the relationship between positional difference of prosthetic hip rotation center and function at 1 month, 3 months, 6 months and 12 months after surgery was analyzed. RESULTS: Of forty-two cases in total, 25 patients were male and 17 patients were female. The age of the patients ranged from 12 and 69 years (median, 38 years). The minimal followup period was 12 months (mean,36 months; range,12-86 months). The complication rate was 31.0% and hip dislocation rate was 7.1%. The overall survival rate was 69.4% at 3 years and 43.7% at 5 years. After 1 month, 3 months, 6 months, the function of the reconstructed hip gradually improved, with MSTS score showing an increasing trend. The MSTS scores at these three time points were compared, the difference was statistically significant (P < 0.05). The improvement of function after 6 months and 12 months was not obvious, with the difference not being statistically significant (P > 0.05). The deviation of hip rotation center in the longitudinal direction and the horizontal direction did not affect the function of the hip (P > 0.05). CONCLUSION: It is safe and effective for patients with pelvic tumor to receive modular hemipelvic prosthesis reconstruction once the prosthesis is fixed in the most firmly position, where soft tissue fully covered, the muscles could be rebuilt more easily and where the eccentricity of the femoral got a certain degree of recovery. The relationship between the deviation of hip rotation center and postoperative function needs to be confirmed.

PDGF-regulated miRNA-138 inhibits the osteogenic differentiation of mesenchymal stem cells.

Differentiation-specific microRNAs may play a critical role in MSC differentiation, and they can be altered by PDGF signaling. We propose that PDGF modulates MSC differentiation by regulating microRNA expression. Therefore, we investigated whether PDGF treatment could alter the expression profile of miRNAs in MSCs. Furthermore, we assessed the osteoblast phenotype of MSCs after inducing osteogenic differentiation. We found that PDGF treatment significantly inhibits the osteogenic differentiation of MSCs and that miR-138 gene transcription is controlled by PDGF signaling. Our results confirm that miR-138 inhibits the osteogenic differentiation of MSCs and suppresses the phosphorylation of FAK, ERK1/2, and Runx2. Furthermore, our study clearly demonstrates that downregulation of Runx2 by miR-138 is critical for the PDGF-mediated inhibition of osteogenic differentiation of MSCs. These findings indicate that inhibition of miR-138 function in MSCs, either by treatment with anti-miR-138 or by overexpression of the miR-138 target sequence (miRNA sponge), could represent a potential therapeutic strategy for the treatment of bone homeostasis disorders caused by activation of the PDGF pathway.

Internal fixation with headless compression screws and back buttress plate for treatment of old Hoffa fracture.

OBJECTIVE: To analyze the early clinical and radiographic outcomes of Hoffa fractures treated by a standard protocol of open reduction and internal fixation using headless compression screws combined with back buttress plate in a consecutive series of 8 Chinese patients. METHODS: Open reduction and internal fixation was performed on all patients. The fractures were anatomically reduced and held temporarily by K-wire. If the ends of fractures were atrophic, autologous bone graft from the ipsilateral iliac crest was packed between the ends. Then the fracture fragments were fixed with AO 6.5 mm headless compression cannulated screws. At least two screws were used to provide rotational stability. One pre-contoured reconstruction plate was placed on the nonarticular surface posteromedially or posterolaterally as back buttress plate. RESULTS: All the patients were followed up for at least 12 months (range 12-25 months). All fractures achieved anatomical reduction and healed clinically and radiographically. At recent follow-up, the mean flexion degree was 120.6° (range 110°-135°) and the mean extension degree was 2.5° (range 0°-5°). The average visual analogue scale score was 1.6 points (range 0-3). Six patients were assessed as excellent and 2 as good according to the hospital for special surgery knee score system. There were no superficial or deep infections, or hardware breakages. No patient had giving way or locking of the knee, though some had intermittent pain and swelling after strenuous exercise. Injury mechanism had significant influence on the functional outcome (P=0.046). CONCLUSION: Headless compression screws combined with back buttress plate and/or autologous bone grafting to treat old Hoffa fracture is one of effective measures. It would be conducive to not only fracture healing but also early exercise and functional recovery.

Functional outcome of en bloc resection and osteoarticular allograft reconstruction with locking compression plate for giant cell tumor of the distal radius.

BACKGROUND: Giant cell tumors of the distal radius at Campanacci grade III are particularly challenging to treat. We have treated 15 cases of giant cell tumor of the distal radius by en bloc excision and osteoarticular allograft reconstruction with locking compression plate (LCP). The purpose of this study was to assess the intermediate outcomes of all patients treated with this surgery. METHODS: From July 2002 to January 2009, we followed up 15 patients with giant cell tumors of the distal radius who were treated with en bloc excision and osteoarticular allograft reconstruction with LCPs that were long enough to approach the distal end of the allograft. All of the cases were evaluated based on clinical and radiologic examinations, the passive range of motion of the wrist joint, complications, Mayo wrist score, and short form (SF)-36. RESULTS: The clinical follow-up time after reconstruction averaged 5.2 years. The mean resected length of the radius was 8.1 cm. One patient had tumor recurrence in the soft tissues after 3 years (recurrence rate 6.67 %). No patient had allograft bone fracture, nonunion, or metastases. Subchondral bone alterations and joint narrowing were present in all cases, with 1 patient suffering from the pain, but the pain could be endured without the need for analgesics. The average range of motion of the wrist was 46.7° of dorsiflexion, 33.3° of volar flexion, 61.3° of supination, and 72.3° of pronation. The mean Mayo wrist score was 70 and the mean modified SF-36 score was 71. CONCLUSIONS: En bloc excision and osteoarticular allograft reconstruction with an appropriate LCP for a Campanacci grade III giant cell tumor of the distal radius result in a reasonable functional outcome at intermediate follow-up evaluation. This method can excise the tumor integrally with a low rate of recurrence, good function, and a satisfactory range of motion.

Infectious complications in patients with crush syndrome following the Wenchuan earthquake.

OBJECTIVE: To analyze the results of clinical and bacteriological examinations in patients with crush syndrome who suffered infectious complications after an earthquake in Sichuan, China. METHODS: A total of 313 bacteriological samples among 147 patients with crush syndrome were collected. Infectious complications, results of microbiological examinations, potential risk factors of infection and mortality were analyzed statistically. RESULTS: In the obtained database, 112 out of the 147 (75.7%) patients had infectious complications, in which, wound infection, pulmonary infection, and sepsis were most common. The time under the rubble and the time from injury to treatment were related to the occurrence of wound infection (P equal to 0.013, odds ratio 2.25; P equal to 0.017, odds ratio 2.31). Sepsis and wound infection were more common in patients who underwent fasciotomy or amputation than in those who did not (P equal to 0.001). CONCLUSION: Quick rescue and injury treatment can decrease the infection risk in crush syndrome patients. It is better to obtain microorganic proofs before applying antibiotics, and bacteriological and drug sensitivity data should be taken into account, especially considering that most of these infections are hospital-acquired and drug resistance. Emphasizing the accuracy and efficiency of wound management in emergency situations, cautiously assessing the indications for fasciotomy to avoid open wounds from unnecessary osteofascial compartment decompression incisions may decrease the incidence of infection and ameliorate the prognosis.

Management of limb fractures in a teaching hospital: comparison between Wenchuan and Yushu earthquakes.

OBJECTIVE: To comparatively analyze the medical records of patients with limb fractures as well as rescue strategy in Wenchuan and Yushu earthquakes so as to provide references for post-earthquake rescue. METHODS: We retrospectively investigated 944 patients sustaining limb fractures, including 891 in Wenchuan earthquake and 53 in Yushu earthquake, who were admitted to West China Hospital (WCH) of Sichuan University. RESULTS: In Wenchuan earthquake, WCH met its three peaks of limb fracture patients influx, on post-earthquake day (PED) 2, 8 and 14 respectively. Between PED 3-14, 585 patients were transferred from WCH to other hospitals outside the Sichuan Province. In Yushu earthquake, the maximum influx of limb fracture patients happened on PED 3, and no one was shifted to other hospitals. Both in Wenchuan and Yushu earthquakes, most limb fractures were caused by blunt strike and crush/burying. In Wenchuan earthquake, there were 396 (396/942, 42.0%) open limb fractures, including 28 Gustilo I, 201 Gustilo II and 167 Gustilo III injuries. But in Yushu earthquake, the incidence of open limb fracture was much lower (6/61, 9.8%). The percent of patients with acute complications in Wenchuan earthquake (167/891, 18.7%) was much higher than that in Yushu earthquake (5/53, 3.8%). In Wenchuan earthquake rescue, 1 018 surgeries were done, composed of debridement in 376, internal fixation in 283, external fixation in 119, and vacuum sealing drainage in 117, etc. While among the 64 surgeries in Yushu earthquake rescue, the internal fixation for limb fracture was mostly adopted. All patients received proper treatment and survived except one who died due to multiple organs failure in Wenchuan earthquake. CONCLUSION: Provision of suitable and sufficient medical care in a catastrophe can only be achieved by construction of sophisticated national disaster medical system, prediction of the injury types and number of injuries, and confirmation of participating hospitals?exact role. Based on the valuable rescue experiences after Wenchuan earthquake, the rescue was faster, more orderly and effective in Yushu earthquake. Nevertheless, there is still a long way to go in the development of a stronger emergent response to the disasters.

[Comparative analysis of the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquakes].

OBJECTIVE: To systematically analyze and compare the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquake, so as to provide useful references for future earthquakes injury rescue. METHODS: Based on the orthopedic inpatients in Lushan and Wenchuan earthquakes, the data of the age, gender, injury causes, body injured parts and speed of transport were classified and compared. RESULTS: The duration of patients admitted to hospital lasted long and the peak appeared late in Wenchuan earthquake, which is totally opposed to Lushan earthquake. There was no significant difference in the patient's age and gender between the two earthquakes. However, the occurrence rate of crush syndrome, amputation, gas gangrene, vascular injury and multiple organ dysfunction syndrome (MODS) in Wenchuan earthquake was much higher than that in Lushan earthquake. Blunt traumas or crush-related injuries (79.6%) are the major injury cause in Wenchuan earthquake, however, high falling injuries and falls (56.8%) are much higher than blunt trauma or crush-related injuries (39.2%) in Lushan earthquake. The incidence rate of foot fractures, spine fractures and multiple fractures in Lushan earthquake was higher than that in Wenchuan earthquake, but that of open fractures and lower limb fractures was lower than that in Wenchuan earthquake. CONCLUSION: The rapid rescue scene is the cornerstone of successful treatment, early rescue and transport obviously reduce the incidence of the wound infection, crush syndrome, MODS and amputation. Popularization of correct knowledge of emergency shelters will help to reduce the damage caused by blindly jumping or escaping while earthquake happens.

[Comparison between allogeneic tendon fixation and screw fixation in ligamentous Lisfranc injury: a biomechanical analysis].

OBJECTIVE: To compare the stability provided by a allogeneic tendon with a screw for the treatment of ligamentous Lisfranc injury. METHODS: Six fresh-frozen, paired cadaveric feet were loaded in the condition of Lisfranc ligament-intact, injury and fixation models. With axial or abduction stress, the distance between medial cuneiform and second metatarsal was recorded. RESULTS: With both two types of stress, there were statistically significant differences in motion detected between the intact and post-injury conditions (all P = 0.000), and the magnitudes were greater with abduction [(4.14 +/- 1.02) mm] than axial load [(1.60 +/- 0.64) mm]. In screw fixation group, the mean position changes under axial load and abduction load were (1.53 +/- 0.62) mm and (4.06 +/- 1.05) mm in post-injury model respectively, while the changes were (0.76 +/- 0.35) mm and (1.20 +/- 0.53) mm in the fixation model (all P = 0.000) which were not statistical different to that in the intact model. In allogeneic tendon fixation group, the mean position changes were (1.66 +/- 0.65) mm and (4.21 +/- 1.00) mm in the post-injury model, while were (0.90 +/- 0.41) mm and (1.33 +/- 0.61) mm in the fixation model (all P = 0.000) which also were not statistical different to that in the intact model. CONCLUSION: Under abduction stress, a significantly greater difference was found between pre- and post-injury, which may be valuable for diagnosing and testing ligamentous Lisfranc injury. Allogeneic tendon fixation can provide similar stability as screw fixation in ligamentous Lisfranc injury.

[A biomechanical comparison of Acutrak headless compression screw and AO cannulated lag screw for the fixation of Hoffa fracture].

OBJECTIVE: To compare the stability, strength of Letenneur type I Hoffa fractures fixed by Acutrak headless compression screws and AO cannulated lag screws. METHODS: 12 models of Letenneur type I Hoffa fractures were randomly divided into 4 groups, which were fixed with two AO cannulated lag screws or Acutrak headless compression screws anteroposteriorly or posteroanteriorly. The stress between two fragments of all specimens was tested. Axial compression test, the cycle load test and the limit load test were successively performed in every specimen. RESULTS: In axial compression test, displacement of Acutrak headless compression screw groups was lower than that of AO cannulated lag screw anteroposteriorly (P < 0.05). The load to failure for Acutrak headless compression screw groups was higher than that of AO cannulated lag screws (P < 0.05), no matter in anteroposterior or posteroanterior direction. CONCLUSION: The strength and stability of Letenneur type I Hoffa fractures fixeded with Acutrak headless compression screw were superior to those provided by AO cannulated lag screw. The direction of screw affects the initial stability for AO cannulated lag screw, other than Acutrak headless compression screw.

Surgical Treatment of Osteosarcoma Induced Distant Pre-Metastatic Niche in Lung to Facilitate the Colonization of Circulating Tumor Cells.

Recently, the major challenge in treating osteosarcoma patients is the metastatic disease, most commonly in the lungs. However, the underlying mechanism of recurrence and metastasis of osteosarcoma after surgical resection of primary tumor remains unclear. This study aims to investigate whether the pulmonary metastases characteristic of osteosarcoma is associated with surgical treatment and whether surgery contributes to the formation of pre-metastatic niche in the distant lung tissue. In the current study, the authors observe the presence of circulating tumor cells in patients undergoing surgical resection of osteosarcoma which is correlated to tumor recurrence. The pulmonary infiltrations of neutrophils and Gr-1+ myeloid cells are characterized to form a pre-metastatic niche upon the exposure of circulating tumor cells after surgical resection. It is found that mitochondrial damage-associated molecular patterns released from surgical resection contribute to the formation of pre-metastatic niche in lung through IL-1ß secretion. This study reveals that surgical management for osteosarcoma, irrespective of the primary tumor, might promote the formation of postoperative pre-metastatic niche in lung which is with important implications for developing rational therapies during peri-operative period.

Preparation of electrospun PLGA-silk fibroin nanofibers-based nerve conduits and evaluation in vivo.

With advances in technical methodology, the grafting of biocompatible conduits may become a viable alternative for the reconstruction of nerve gaps. In this study, electrospinning was used to fabricate nerve conduits (NCs) from poly(L-lactide-coglycolide)-silk fibroin. Conduits or autograft nerves were employed to bridge 10 mm defects in the sciatic nerves of Sprague-Dawley rats. Six weeks after the operation, morphological and functional assessment showed that nerve conduits from PLGA-silk fibroin grafts promoted the regeneration of peripheral nerves. The effects were similar to those obtained using nerve autografts. This method offers a promising alternative to the use of nerve autografts.

Timing of internal fixation and effect on Schatzker IV-VI tibial plateau fractures.

OBJECTIVE: To study the effect of internal fixation performed at different times on therapeutic outcomes of Schatzker IV-VI tibial plateau fractures. METHODS: The clinical data of 42 cases of Schatzker IV-VI tibial plateau fractures treated in our department were analyzed retrospectively. Among these 42 patients, 21 received surgical treatment within 12 h after injury (Group I), the other 21 were first treated by traction or plaster fixation followed by a delayed internal fixation after soft tissue swelling subsided (Group II). The surgical time, complications, length of hospital stay, cost of hospitalization, and time for fracture union, as well as functional recovery were analyzed and compared between the two groups. RESULTS: After 10-28 months follow-up (mean 16.5 months), except 5 cases who lost to follow-up, no differences were found between the two groups regarding surgical time, preoperative and postoperative complications, healing time or the Hospital for Special Surgery (HSS) score at the end of follow-up, but significant differences were found in the length of hospital stay, cost of hospitalization and HSS score at 3 months after operation (P less than 0.05). CONCLUSION: Under certain conditions, early internal fixation for Schatzker IV-VI tibial plateau fracture is feasible, which can shorten the length of hospital stay, decrease the cost of hospitalization and promote early functional rehabilitation.

[Application of n-HA/PA66 composite artificial vertebral body in anterior reconstruction of lower cervical spine fracture and dislocation].

OBJECTIVE: To initially evaluate the application of artificial vertebra of n-HA/PA66 in anterior reconstruction of lower cervical spine fracture and dislocation. METHODS: In this study, 84 patients with lower cervical spine fracture and dislocation received anterior cervical discectomy, spinal canal decompression or subtotal corpectomy, spinal canal decompression and reconstruction by n-HA/PA66 composite artificial vertebral body combined with plate instrumentation. Neurological function was followed up by improvement rate of Frankel and situations of the supporting body was observed by X ray and 3D-CT in 3, 12, 24 months postoperatively. The intervertebral height, physical arc (reflected by Cobb angle) and the locations and fusion rate of the supporting body were assessed in order to evaluate the stability of the cervical spine and alignment improvements. RESULTS: All the patients underwent operation successfully and were followed up for 6 to 24 months with an average of 12 months. The preoperative symptoms were improved to varying degrees. Imaging studies showed that in all cases graft fusion were achieved, and cervical alignments, intervertebral height, cervical spine stability and the locations of the artificial vertebral body were well maintained. No displacement and subsidence of the artificial vertebral body occurred. Postoperative immediate intervertebral height (2.4 ± 0.2) cm, preoperative intervertebral height (1.9 ± 0.1) cm, comparisons of the two groups was statistically significant (q = 2.48, P < 0.001). The immediate, 3 month, 1 year, 2 year period follow-up group intervertebral height was not statistically significant (P > 0.05). Preoperative Cobb angle was 9.8° ± 1.2°, postoperative immediate Cobb angle was 16.6° ± 1.2°, comparisons of the two groups was statistically significant (q = 14.25, P < 0.001). The immediate, 3 month, 1 year, 2 year period follow-up group Cobb angle was not statistically significant (P > 0.05). CONCLUSIONS: n-HA/PA66 artificial vertebral body can provide early cervical spine support and stability and effectively maintain the biological alignment and cervical intervertebral height. It has high rate of graft fusion and is convenient to observe by X-ray. Therefore, n-HA/PA66 can be taken as an ideal graft for anterior lower cervical spine fracture and dislocation operation, but further follow-up study is still required to evaluate the long-term effects.

[Appling the color Doppler in abdominal aortic balloon occlusion for pelvic and sacral surgery].

OBJECTIVE: To apply the color Doppler in abdominal aortic balloon occlusion for pelvic or sacral surgery, and to evaluate its effectiveness in controlling blood loss. METHODS: A Philips 4500 color Doppler was used to place abdominal aortic balloons in 20 patients with pelvic or sacral tumors who underwent surgery. The temporary abdominal aortic balloons were used for controlling blood loss in the surgery. Transesophageal echocardiography was performed to detect the renal blood flow. RESULTS: Abdominal aortic balloons were successfully placed to the 20 patients, with a water injection rate of 10-18 (13.8 +/- 2.6) mL and a total of 45-180 min occlusion during the 70-450 (265 +/- 102) min surgery. The intraoperative blood loss ranged from 250 to 4000 (1357 +/- 997) mL. The water injection rate of abdominal aortic-balloons (Y) was correlated with the diameter of abdominal aorta (X): Y = 7.1602X + 2. 9968 (R2 = 0.7371, P < 0.05). Renal blood flow was not affected. The patients stayed in hospital for 7-13 (9.8 +/- 11.9) days after operation. One patient developed complications. The one year recurrence rate of tumors was 10%. CONCLUSION: The color Doppler provides a simple and accurate instrument for abdominal aortic-balloon occlusion, with reliable blood loss control.

[Finite element analysis and static biomechanics of pelvic after modular hemipelvic prosthesis reconstruction].

OBJECTIVE: To compare the stress distribution of normal pelvis with those of postoperative contralateral pelvic and modular hemipelvic prosthesis under different positions, with an aim to providing biomechanical evidence support for safe reconstruction of pelvic ring using modular hemipelvic prosthesis. METHODS: Three-dimensional finite element models of normal pelvis, postoperative pelvic and modular hemipelvic prosthesis were established using thin-layer CT scanning (TLCS). The stress distributions of normal pelvis, postoperative pelvic and prosthesis were measured under three static positions: standing on two feet, standing on one foot on the defective side and sitting. RESULTS: Little difference was found in contralateral pelvic stress between the normal pelvic and reconstructive pelvic models given the same load with different positions. The maximum stress level appeared at the upside of sacrum mesion, sacroiliac joints, superior greater sciatic notch and iscbial tuberosity, albeit a much lower level than fatigue strength. The maximum stress level of modular hemipelvic prosthesis appeared at the inner wall of connector bar between CS fixation and acetabular cup. Similarly, the stress level was also much lower than the fatigue strength of connector bar. The stress distribution of postoperative pelvic was similar to that of normal pelvic. CONCLUSION: Reconstruction with modular hemipelvic prosthesis has little effect on contralateral pelvic. The maximum stress levels of contralateral pelvis and modular hemipelvic prosthesis are significantly lower than their fatigue strength, which indicates sound safety of contralateral pelvis and modular hemipelvic prosthesis. Pelvic reconstruction with modular hemipelvic prosthesis produces good biomechanical compatibility.