Objective To investigate the effects of mefformin on the differentiation of osteoclastas well as relative mechanism.Methods Raw264.7 cells from the murine macrophage cell line was used.Receptor activator of NF-κB ligand (RANKL) was used to stimulate osteoclast differentiation from Raw264.7 cells.Osteoclast differentiation was assessed by tartrate-resistant acid phosphatase (TRAP) and actin fluorescence staining and counting the TRAP-positive cells after exposure to different concentrations of mefformin (0 μmol/L,400 μmol/L,800 μmol/L and 1000 μmol/L) or rapamicin (100 nmol/L) in the presence of 50 ng/ml RANKL for 5 days.Bone-resorbing activity was evaluated by BD BioCoatTM OsteologicTM Bone Cell Culture System.The expression of osteoclast-specific genes like TRAP,capthesin K,calcitonin receptor (CTR) and matrix metalloproteinase (MMP-9) was evaluated by RT-PCR.The expression of tumor necrosis factor-α(TNF-ct) S6K1Thr389,S6 Ser235/236,4E-BP1Thr37/46 and c-Fos protein was evaluated by ELISA kit and Western blot analysis,respectively.Results Mefformin dose-dependently inhibited RANKL-stimulated osteoclasts differentiation in Raw264.7 cell culture,as manifested by decrease of TRAP-positive multinucleated cells and pit erosion area,down-regulation of TRAP,cathepsin K,CTR and MMP-9 mRNA and reduction of TNF-α and c-Fos protein expression.Further study revealed that RANKL activated mTOR complex 1(mTORC1) signaling,while mefformin impaired RANKL-stimulated mTORC1 signaling.Rapamycin,an mTORCl-specific inhibitor and immunosuppressive macrolides could also prevent RANKL-induced osteoclast differentiation and bone resorption in vitro.Conclusion Mefformin inhibits osteoclastogenesis in vitro,which may due to reduction of TNF-α and c-Fos protein expression,and mTORC1 signaling is involved in this process.

Objective:To evaluate the anterior expansion of sacral foramen and decompression of sacral plexus via the lateral-rectus approach (LRA) in the surgical treatment of sacral fractures complicated with sacral plexus injury.Methods:From January 2013 to June 2018, 11 patients were treated at Department of Orthopaedics, The Third Hospital Affiliated to Southern Medical University for obsolete sacral fractures complicated with sacral plexus injury. They were 8 males and 3 females, aged from 17 to 54 years (average, 38 years). According to the Denis classification, all the sacral fractures belonged to Denis Zone Ⅱ. According to British Medical Research Council (BMRC) grading system, the nerve injury was complete damage in 2 cases and partial damage in 9. The mean time from injury to surgery was 6 months (range, from 0.7 to 12.0 months). After the sacroiliac joint was exposed via the LRA, the lumbosacral trunk was exposed and released between iliac vessels and the iliopsoas. Next, the S1 foramen was expanded and the S1 nerve root was released after separation of the median sacral artery and the internal iliac artery. Reduction and fixation of the sacroiliac joint was carried out for patients with unstable sacral fracture. X-ray and CT examinations of the pelvis were performed to evaluate fracture healing and neurological function recovery postoperatively.Results:Of this cohort of 11 cases, operation succeeded in 10 but failed in one whose sacral fracture was found to have completely healed with the S1 foramina totally occluded. The surgical time averaged 110 min (range, from 70 to 220 min) and the blood loss 1, 100 mL (range, from 450 to 2, 800 mL). Postoperative X-ray and CT examinations showed that the sacral foramens were expanded significantly without any complications. The follow-up time averaged 18 months (range, from 12 months to 4 years). By the BMRC grading system at the last follow-up, the neural function was completely recovered in 5 cases, partially recovered in 4 cases and not recovered in one.Conclusion:Significant anterior expansion of sacral foramen and decompression of sacral plexus via the LRA is a viable and effective alternative for treatment of sacral fractures complicated with sacral plexus injury.

Objective:To explore the efficacyof direct anterior approach (DAA) combined with direct posterior approach (DPA) for the treatment of Pipkin IV fracture.Methods:Data of 18 patients with Pipkin IV fracture treated through DAA combined with DPA from January 2016 to April 2019 was retrospectively analyzed. There were 13 males and 5 females, with an average age of 43.2 years (range,19-56 years). Fractures were caused by traffic accident in 15 and by falling in 3. The fracture lines of 13 cases were located below the fovea of the femoral head and 5 cases were located above the fovea. According to Letournel-Judet classification for acetabular fractures, there were 14 cases of posterior acetabular wall fractures, 2 cases of posterior wall fractures involving posterior column, and 2 transverse plus posterior wall fractures. The operation was performed through DAA approach to treat the femoral head fractures, and DPA approach was used to treat acetabular fractures. Radiographs and CT scans of the pelvis were reexamined after surgery, and fracture reduction, healing, and complications such as femoral head necrosis, sciatic nerve injury, superior gluteal neurovascular injury and heterotopic ossification were evaluated. Quality of acetabular reduction was evaluated according to the criteria proposed by Matta. Thompson-Epstein scoring system was used to evaluate hip function.Results:The average operation time was 133 min (range, 75-205 min). And the average blood loss was 371 ml (range, 240-600 ml). All 18 patients were followed up for 6 to 36 months, with an average period of 15.7 months. All fractures healed 10 to14 weeks after surgery. Three patients had symptoms of sciatic nerve injury after the injury, who recovered 6 to 12 weeks after the operation. All femoral head fractures were reduced. According to Matta criteria of reduction quality, anatomic reduction was gained in 13 cases, and satisfactory reduction was obtained in 3 cases, while unsatisfactory reduction was found in 2 cases, and the overall satisfactory rate was 88.9%(16/18). Two patients had Brooker I level heterotopic ossification. There was no iatrogenic vascular injury, avascular necrosis of femoral head, infection, internal fixation failure or other complications. According to the Thompson-Epstein scoring system at the latest follow-up, the functional results of the affected hip were excellent in 7 cases, good in 8, fair in 2 and poor in 1.Conclusion:Treatment of Pipkin IV fractures through DAA combined with DPA approach reduces surgical invasion. And it can directly reduce and fix the femoral head and posterior acetabular fracture, and protect the important structures such as the arteriae circumflexa femoris medialis, sciatic nerve and lateral femoral cutaneous nerve, and reduce the occurrence of complications such as femoral head necrosis and heterotopic ossification. Therefore, DAA combined with DPA is aneffective method for the treatment of Pipkin IV fractures.

Objective To evaluate the clinical outcome of bleeding control by preoperative embolization of internal iliac artery with DSA and intra?operative presetting abdominal aorta balloon, combine with the operation techniques of exposure, reduc?tion and internal fixation of pelvic fracture through lateral?rectus approach. Methods From March 2012 to May 2015, 7 patients with type C3 pelvic fractures admitted to our department from March 2012 to May 2015, treated with preoperative embolization of internal iliac artery under digital subtraction angiography 2 h before surgery and presetting abdominal aorta balloon were retrospec?tively reviewed. There were 3 males and 4 females, with an average age of 34 years (range, 16 to 61 years). According to AO classi?fication, all 7 cases belonged to type C3 (3.2:5 cases;C3.3:2 cases), including 5 cases with limb fracture, 2 cases with craniocere?bral trauma, 4 cases with pulmonary contusion, 2 cases with injury of abdominsal organs. Time from injury to operation was 19 days on average (10 to 33 days). Patients received damage control surgery treatment including bleeding control and temporary ex?ternal fixation, and ipsilateral tractions with heavy weight, intensive care and corrections of general situation before operation. The fracture model was manufactured by 3D printing and fracture reduction was simulated on computer preoperatively. Embolization of internal iliac artery was performed in the side of severe displaced sacroiliac joint with DSA 2 hours preoperatively. Reduction was performed to stabilize anterior-posterior pelvic ring and acetabular fractures via the intraoperative lateral?rectus approach. And 2 cases were performed by temporary balloon occlusion of abdominal aorta (≤60 min) for bleeding control in reduction of in the side of sacroiliac joint fractures. Results All the 7 cases had undergone the operations successfully, and the operating time was from 135-320 min with blood loss from 440-3 350 ml. According to Matta radiological evaluation postoperatively, reduction of pelvic fracture was rated as anatomic in 5 cases, satisfactory in 2, without complications. All 7 cases were complicated with lumbosacral plexus injury or lumbosacral trunk injury at different degrees (M0 2 cases, M1 2 cases, M2 2 cases, M3 1 case). According to the BMRC scoring system, 5 cases had well recovered and the other 2 cases had no improvement after three months (M4 2 cases, M5 3 cases). Conclusion Surgical management of pelvic fracture through preoperative internal iliac artery embolization and intra?oper?ative occlusion of abdominal aorta could effective control bleeding and achieve favorable conditions for reduction. Lateral?rectus approach can provide adequate exposure of the anterior and posterior ring, and this approach could also provide excellent visual control of reduction and fixation.

This study showed a case of a patient with central dislocation of the femoral head without involvement of anterior or posterior column of the acetabulum. The patient was associated with endocrine disorders caused by pituitectomy, severe osteoporosis caused by a long-term gulucocorticoids intake history, and poor bone quality of the quadrilateral plate. The direct impact of the femoral head on the quadrilateral plate after trauma resulted in purely central dislocation of the femoral head. 3D printing technique was used to print the fracture model for observation of the fracture morphology and the simulated operation before surgery. The variable-angle locking acetabular plate with a propeller-like shape was designed on the basis of the mirror of the ipsilesional semi-pelvis. This fracture was reduced via the lateral-rectus approach under direct vision. The quadrilateral surface fractures were fixed by the variable-angle locking acetabular plate which was used as a template for reduction. The follow up after surgery showed good reduction and fixation, equal length of double lower limbs, good positive and passive motion of the injured hip joint and without perioperative complications. This report describes an isolated quadrilateral plate fracture that has not yet been classified. It was effectively treated by using a customized variable-angle locking acetabular plate with a propeller-like shape via the lateral rectus approach.

OBJECTIVETo study the clinical effect and surgical operating points of pararectus approach for the internal fixation of acetabular both-column fractures with concurrent displaced quadrilateral plate fractures.

METHODSFrom January 2012 to December 2013, in the Third Affiliated Hospital of Southern Medical University, 15 patients with acetabular both-column fractures and displaced quadrilateral plate fractures were surgically managed through the pararectus approach. There were 11 male and 4 female patients, with an average age of 40 years (from 19 to 61 years). According to Judet-Letournel classification, there were 9 anterior column plus posterior hemitransverse fractures, 6 both-column fractures, 8 cases involving the pelvic fracture. All these fractures were treated through the pararectus approach, in the horizontal position with general anesthesia. The pre-bended plate was placed in interior pelvic ring to fix the anterior wall, anterior column and quadrilateral plate in direct sight. Then, the posterior column was exposed and fixed with antegrade lag screw. Patients were followed up in 4 weeks, 12 weeks, 6 months, 1 year after the operation, and the anteroposterior radiograph of pelvis and the X-ray examination of the fractured hip was performed.

RESULTSAll the 15 cases underwent the operation successfully. Postoperative X-ray and CT exams showed excellent and good reduction of anterior column, posterior column and quadrilateral plate, with none surgical complication occurred. According to the Matta radiological evaluation postoperatively, reduction of acetabular fracture was rated as excellent in 9 cases, good in 3 cases and poor in 3 cases. The rate of excellent and good was 12/15. After 8 to 18 months' follow-up (median follow-up time was 14 months), all the patients gained bone union. According to the modified Merle D'Aubigne and Postel scoring system, 9 cases were excellent, 4 were good, and 2 were fair. The rate of excellent and good was 13/15.

CONCLUSIONSSurgical management of acetabular fractures through the pararectus approach can provide adequate exposure of reducing and fixing both-column acetabular fractures with concurrent displaced quadrilateral plate fractures, which has a good effect in clinical application.

Acetabulum ; pathology ; surgery ; Adult ; Anesthesia, General ; Bone Plates ; Bone Screws ; Female ; Fracture Fixation, Internal ; methods ; Hip Fractures ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Pelvic Bones ; pathology ; surgery ; Postoperative Period ; Spinal Fractures ; Treatment Outcome ; Young Adult

Objective: To explore surgical technique and clinical results of the direct posterior approach (DPA) for acetabular fractures involving posterior column, posterior wall, or posterior column and wall. Methods: From January 2016 to June 2017, data of 10 cases (7 males, 3 females, an average age of 37 years, ranging from 17 to 54 years) with posterior acetabular fractures treated by the DPA were retrospectively analyzed. Fractures were caused by traffic accident in 6 cases and by falling in 4 cases. According to Letournel-Judet classification of acetabular fractures, there were 6 cases of posterior acetabular wall fractures, 4 cases of posterior wall fractures involving posterior column. A straight skin incision was made from the middle of the line between the posterior margin of the tip of the femoral greater trochanter and the posterior superior iliac spine, to the posterior margin of the femoral greater trochanter. The gluteus maximus muscle was cleaved longitudinally. A view of the area from hip capsule to the superior margin of the greater sciatic foramen was obtained by entering along the interspace of the gluteus medius and pyriformis muscle, and the superior gluteal neurovascular bundle was protected. Acetabular posterior column and posterior wall fractures were reduced and fixed under direct vision. The fracture reduction, fracture healing, femoral head necrosis, sciatic nerve injury, superior gluteal neurovascular injury and heterotopic ossification were evaluated by the postoperative X-ray and CT examination. The function of hip joint was assessed by the Merle d’Aubigné-Posteal score modified by Matta. Results: The average operative incision length was 9.6 cm (range, 8-11 cm). The average operation time was 50 min (range, 35-80 min). The average blood loss was 310 ml (range, 200-440 ml). The time of follow-up was 12-30 months. All the patients were healed within 8-12 weeks without any complications such as superior gluteal nerve injury, superior gluteal vessel injury, or sciatic nerve injury. One case of acetabular posterior wall and posterior column fracture with posterior dislocation of hip joint, suffered from femoral head necrosis at the 9th months after surgery, which was treated by total hip arthroplasty and was recovered one year after surgery. In one case of actebular posterior wall and posterior column fracture, heterotopic ossification occurred 3 month after operation, without any special treatment and the hip joint activity was not affected at the follow-up of 15 months after surgery. During the 12-month follow-up after surgery, the Merle d’Aubigné-Postel score modified by Matta was 13-18, among which there were excellent in 6 cases, good in 2, acceptable in 2, with an overall excellent and good rate of 80% (8/10). Conclusion The direct posterior approach for posterior acetabular fractures can obtain satisfactory clinical results. The advantages of the DPA include decreasing trauma, shortening operation time, reduing blood loss and decreasing risks of iatrogenic injury to the gluteus medius muscle, the external rotators, the arteriae circumflexa femoris medialis and sciatic nerves as well as reducing and fixing the fractures under direct vision. Thus, the DPA is a relatively safe surgical approach for acetabular posterior wall/column fracture.

Objective:To investigate the clinical efficacy of lateral-rectus approach(LRA) for vertical shear fracture of pelvis combined with lumbosacral plexus nerve injury.Methods:A retrospective study was conducted of the 37 patients who had been treated at Department of Orthopaedics, The Third Affiliated Hospital to Southern Medical University for vertical shear pelvic fracture combined with lumbosacral plexus nerve injury from August 2010 to August 2018. They were 25 males and 12 females, aged from 18 to 61 years (mean, 36.2 years). By the Tile classification, there were 31 cases of type C1.3, 5 cases of type C2 and one of type C3. LRA was used in all the patients to explore and release the lumbosacral plexus nerve and to reduce the sacral fracture. The posterior ring was fixated with an anterior iliac plate or sacral screws before fixation of the anterior ring and treatment of the acetabular fracture. The operation time, intraoperative bleeding volume, quality of fracture reduction, fracture union time and recovery of nerve and muscle strength were recorded.Results:For this cohort, the operation time ranged from 105 to 228 minutes (mean, 155.0 minutes) and the intraoperative bleeding volume from 680 to 2, 440 mL (mean, 1, 070 mL). Thefollow-up time ranged from 1 to 8 years (average, 2 years). According to the Matta criteria, the quality of fracture reduction was evaluated as excellent in 21 cases, as good in 12 cases and as fair in 4 cases, giving an excellent and good rate of 89.2%. Follow-ups revealed reduction loss in 4 patients, nonunion and reduction loss in one patient and bony union in the other 32 patients after 8 to 12 weeks (mean, 10.1 weeks). According to the criteria by the Nerve Injuries Committee of the British Medical Research Council (BMRC), the recovery of nerve and muscle strength achieved M5 (full recovery of neurological symptoms) in 22 cases, M4 (fine recovery of neurological symptoms) in 7 cases, M1, M2 and M3 (partial recovery of neurological symptoms) in 5 cases, and M0 (no recovery of neurological symptoms) in 3 cases.Conclusion:LRA is an ideal surgical approach for treatment of pelvic vertical shear fractures complicated with lumbosacral plexus nerve injury, because it can well expose the medial pelvic joint from the sacroiliac joint to the symphysis pubis, allow direct release of the lumbosacral plexus nerve compressed and stretched, and, together with traction of the lower limbs, lead to satisfactory fracture reduction.

Objective:To explore the surgical indications, techniques and methods of closed reduction and minimally invasive fixation for the treatment of pelvic fractures of Tile C2 and C3, and evaluate the clinical efficacy.Methods:A retrospective analysis of the data of 20 cases with Tile C2 and C3 pelvic fractures treated with closed reduction and minimally invasive fixation from January 2016 to July 2019. There were 7 males and 13 female, with an average age of 35.6±14.6 years (range 12-60 years). The time from injury to operation was 5-30 d, with an average of 19.3±7.1 d. Tile classification of pelvic fracture: 13 cases of C2 type and 7 cases of C3 Type. 2 cases were complicated with ipsilateral or bilateral lumbosacral nerve injury. Classification of nerve injury: 2 cases were partial injury, British Medical Research Council (BMRC) Grade M3. The operation is treated with closed reduction and minimally invasive fixation. First, the side with obvious displacement is fixed on the operating table with a pelvic reduction frame, and the side with less displacement is traction. After reduction, insert S 1 and S 2 sacroiliac screw guide-pin on this side to the contralateral sacral fracture. And then change the traction, fix the reset side on the operating table, change the side with obvious traction displacement, after the reset is ideal, pass the inserted guide-pin through the contralateral sacroiliac joint to the outer iliactable. Then insert the sacroiliac screw. The patients complicated with acetabular fracture were reduced and fixed by the corresponding approach, and the anterior ring was fixed by INFIX. The operation time, intraoperative bleeding volume and postoperative complications were recorded. The quality of fracture reduction was evaluated by Matta's criteria, and the clinical effect was evaluated by Majeed score. Results:All the 20 patients successfully completed the operation. The operation time was 105-210 min, with an average of 167.00±31.21 min. The intraoperative bleeding volume was 30-100 ml, with an average of 82.00±5.36 ml. Postoperative X-ray and CT showed that the fracture was reduced and fixed. According to the Matta's criteria, the reduction quality was rated as excellent in 14 cases, good in 4 case, fair in 2 case, with an excellent and good rate of 90%. Two patients showed symptoms of lateral femoral cutaneous nerve injury without other complications related to surgery. Follow-up for 1 to 4 years, the fractures healed, and the healing time was 6 to 12 weeks. According to the Majeed score, the result was rated as excellent in 18 cases, good in 2 case, with an excellent and good rate of 100%.Conclusion:Closed reduction and minimally invasive fixation for the treatment of pelvic fractures of type C2 and C3, with the characteristics of less damage and good results, will become a trend in the treatment of pelvic fractures.

Objective:To investigate the application of three-dimensional (3D) image fusion technique of pelvic enhanced CT and magnetic resonance neurography (MRN) on the patients of pelvic fractures with lumbosacral plexus injury.Methods:From January 2019 to December 2020, 15 patients (11 males, 4 females, mean age 26.67±11.34 of pelvic fracture (AO classification C1.3 of 11 cases, C2 of 2 cases, C3 of 2 cases) with lumbosacral plexus injury underwent 3D image fusion of pelvic enhanced CT and MRN. All patients exhibited lower limb nerve dysfunction after injury. The preoperative muscle strength were evaluated by British Medical Research Council (BMRC) criteria: grade 0 in 2 cases, grade 1 in 5, grade 2 in 7 and grade 3 in 1. Physical examination and enhanced CT combined with MRN 3D image fusion technology were used to accurately determine the injury site of lumbosacral plexus nerve, fracture displacement, and the direction of blood vessels and ureters, and develop corresponding surgical plans. The neurological functions were measured in post-operation follow-up.Results:All 15 operations were successfully completed and the site of lumbosacral plexus injury during operation was consistent with preoperative fusion image, and inconsistency of injury characteristic in 4 patients (4/15, 27%). Among the 6 cases of laparoscopic surgery, 2 cases were changed to open surgery because of the difficulty of nerve decompression. The average time of 4 cases of laparoscopic surgery was 116.27±26.46 min and intraoperative blood loss was 102.50±79.32 ml. The average time of 11 cases of open operation was 123.64±38.28 min, and intraoperative blood loss was 713.64±393.12 ml. For the opening operations, 9 cases were successfully decompressed, and nerve disruption was observed in 2 patients. All 15 patients were followed up. The average follow-up time was 9.33±2.19 months. The radial bony healing was observed in each case at the end of follow-up, mean healing time was 5.03±1.04 months (range, 3-6 months). In addition, patients' muscle strength recovered, 8 cases of grade 5, 3 cases of grade 4, 1 case of grade 3, 1 case of grade 2, and 2 cases of grade 0 after surgery. The difference was statistically significant ( Z=3.27, P<0.001). On the other hand, in sensory function assessment, there were 8 cases of grade S5, 1 case of grade S4, 3 cases of grade S3, 1 case of grade S2 and 2 cases of grade S0 after surgery. Conclusion:3D image fusion of enhanced CT and MRN can accurately locate and characterize pelvic fractures combined with lumbosacral plexus injury before surgery, accurately guide the formulation of surgical plan, and reduce surgical trauma and related complications.