Objective To explore a new method for the pre-degeneration of peripheral nerve in vitro for obtaining many effective Schwann cells so as to provide a large number of seed cells for the research and application of tissue engineered nerves. Methods The bone marrow derived cells (BMDCs) from transgenic green fluorescent protein C57BL/6 mouse and the sciatic nerve segments from the C57BL/6 mouse were co-cultured to prepare the pre-degeneration of sciatic nerve in vitro (experimental group, group A), and only sciatic nerve was cultured (control group, group B). At 7 days after culture, whether BMDCs can permeate into the sciatic nerve in vitro for pre-degeneration was observed by gross and immunohistofluorescence staining. And then Schwann cells were obtained from the sciatic nerves by enzymic digestion and cultured. The cell number was counted, and then the purity of primary Schwann cells was determined using immunohistofluorescence staining and flow cytometer analysis. Results At 7 days after pre-degeneration, gross observation showed that enlargement was observed at nerve stumps, and neuroma-like structure formed; the group A was more obvious than group B. Immunohistofluorescence staining showed many BMDCs permeated into the nerve segments, with positive F4/80 staining in group A. After culture, the yield of Schwann cells was (5.59 ± 0.19) × 104 /mg in group A and (3.20 ± 0.21) × 104/mg in group B, showing significant difference (t=2.14, P=0.03). At 48 hours after inoculation, the cells had blue bipolar or tripolar cell nuclei with small size and red soma by immunohistofluorescence staining; fibroblasts were flat polygonal with clear nucleus and nucleolus, showing negative p75NTR staining; and there were few of fibroblasts in group A. The purity of Schwann cells was 88.4% ± 5.8% in group A and 76.1% ± 3.7% in group B, showing significant difference (t=2.38, P=0.04). And the flow cytometer analysis showed that the purity was 89.6% in group A and 74.9% in group B. Conclusion BMDCs can promote the pre-degeneration of peripheral nerve in vitro, and it is a new method to effectively obtain Schwann cells for tissue engineered nerve.
ObjectiveTo evaluate the feasibility and effectiveness of percutaneous screwdriver rod-assisted closed reduction in the treatment of valgus-impacted femoral neck fractures. MethodsBetween January 2021 and May 2022, 12 patients with the valgus-impacted femoral neck fractures were treated with percutaneous screwdriver rod-assisted closed reduction and femoral neck system (FNS) internal fixation. There were 6 males and 6 females with a median age of 52.5 years (range, 21-63 years). The fractures were caused by traffic accident in 2 cases, falling in 9 cases, and falling from height place in 1 case. All were unilateral closed femoral neck fractures, including 7 on the left side and 5 on the right side. The time from injury to operation was 1-11 days, with an average of 5.5 days. The fracture healing time and postoperative complications were recorded. The quality of fracture reduction was evaluated by Garden index. At last follow-up, Harris score was used to evaluate the hip joint function, also the shortening of femoral neck was measured. ResultsAll the operations were successfully completed. After operation, the incision fat liquefaction occurred in 1 case, which healed after enhanced dressing change, and the other patients’ incisions healed by first intention. All patients were followed up 6-18 months, with an average of 11.7 months. The X-ray film reexamination showed that the quality of fracture reduction was grade Ⅰ in 10 cases and grade Ⅱ in 2 cases according to the Garden index. All fractures reached bony union, and the healing time was 3-6 months, with an average of 4.8 months. At last follow-up, the femoral neck was shortened by 1-4 mm, with an average of 2.1 mm. No internal fixation failure or osteonecrosis of the femoral head occurred during follow-up. At last follow-up, the hip Harris score was 85-96, with an average of 92.4; 10 cases were rated as excellent and 2 were good. Conclusion The percutaneous screwdriver rod-assisted closed reduction can effectively reduce the valgus-impacted femoral neck fracture. It has the advantages of simple operation, effective, and less impact on blood supply.
Objective To investigate the surgical technique and effectiveness of titanium elastic nail (TEN) assisted retrograde channel screw implantation of superior pubic branch. Methods The clinical data of 31 patients with pelvic or acetabular fractures treated with retrograde channel screw implantation in superior pubic branch between January 2021 and April 2022 were retrospectively analyzed. Among them, 16 cases were implanted with assistance of TEN (study group) and 15 cases were implanted under the guidance of C-arm X-ray machine (control group). There was no significant difference in gender, age, cause of injury, Tile classification of pelvic fracture, Judet-Letournal classification of acetabular fracture, and time from injury to operation between the two groups (P>0.05). The operation time, fluoroscopy times, and intraoperative blood loss of each superior pubic branch retrograde channel screw were recorded during operation. X-ray films and three-dimensional CT were reexamined after operation, the quality of fracture reduction was evaluated by Matta score standard, and the position of channel screw was evaluated by screw position classification standard. The fracture healing time was recorded during the follow-up, and the postoperative functional recovery was evaluated by Merle D’Aubigne Postel score system at last follow-up. Results Nineteen and 20 retrograde channel screws of superior pubic branch were implanted in the study group and the control group, respectively. The operation time, fluoroscopy times, and intraoperative blood loss of each screw in the study group were significantly less than those in the control group (P<0.05). According to the postoperative X-ray films and three-dimensional CT, none of the 19 screws in the study group penetrated out of the cortical bone or into the joint, and the excellent and good rate was 100% (19/19); in the control group, there were 4 screws of cortical bone penetration, and the excellent and good rate was 80% (16/20); the difference between the two groups was significant (P<0.05). Matta score standard was used to evaluate the quality of fracture reduction, there was no patient in the two groups with poor reduction results, and the difference was not significant between the two groups (P>0.05). The incisions of the two groups healed by first intention, and there was no complication such as incision infection, skin margin necrosis, and deep infection. All patients were followed up 8-22 months, with an average of 14.7 months. There was no significant difference in healing time between the two groups (P>0.05). At last follow-up, the difference in functional recovery evaluated by the Merle D’Aubigne Postel scoring system between the two groups was not significant (P>0.05). Conclusion TEN assisted implantation technique can significantly shorten the operation time of retrograde channel screw implantation of superior pubic branch, reduce the times of fluoroscopy, and have less intraoperative blood loss and accurate screw implantation, which provides a new safe and reliable method for minimally invasive treatment of pelvic and acetabular fractures.
Objective To investigate the effectiveness of modified internal fixator (INFIX) to fix the anterior pelvic ring for Tile C1.3 pelvic fracture by comparing with the traditional INFIX. MethodsThe patients with Tile C1.3 pelvic fractures admitted between April 2018 and June 2021 were taken as the study objects. Of them, 55 cases were included in the study according to the selection criteria. During operation, the anterior pelvic ring was fixed with the modified INFIX in 30 cases (modified group) and with the traditional INFIX in 25 cases (control group). The posterior pelvic ring in 55 cases was fixed with sacroiliac screws. There was no significant difference between the two groups in gender, age, cause of injury, time from injury to operation, and combined injury (P>0.05). The operation time, intraoperative blood loss, and complications were recorded and compared between the two groups. The X-ray film was taken to evaluate the reduction of the anterior pelvic ring after operation, grade the reduction according to the Matta scoring standards, and observe the fracture healing and healing time. The function was evaluated according to Majeed scoring standards during follow-up. Results The operation time of the modified group was significantly longer than that of the control group (Z=–3.837, P<0.001), but there was no significant difference in the intraoperative blood loss between the two groups (t=–1.831, P=0.076). All patients were followed up 12-18 months (mean, 14 months). X-ray film reexamination showed that the excellent and good rate of Matta scoring for anterior pelvic ring reduction in the modified group was 88.00%, which was significantly better than that in the control group (63.33%) (χ2=4.373, P=0.037). All fractures healed, and the fracture healing time of the modified group and the control group was (12.04±3.59) and (14.83±4.83) weeks respectively, with a significant difference (t=2.401, P=0.020). At last follow-up, the excellent and good rates of Majeed scoring were 80.00% in the modified group and 76.67% in the control group, with no significant difference (χ2=0.089, P=0.766). In the modified group, 2 cases (8%) had complications, all of which were incision infection above pubic symphysis. In the control group, 9 cases (30%) had complications, including 5 cases of lateral femoral cutaneous nerve injury, 2 cases of femoral nerve paralysis, and 2 cases of delayed fracture healing. The incidence of complications was significantly lower in the modified group than in the control group (χ2=4.125, P=0.042). ConclusionCompared with the traditional INFIX, the modified INFIX to fix the anterior pelvic ring for Tile C1.3 pelvic fracture has fewer complications, better stability, shorter fracture healing time, and lower risk of nerve injury.
Objective To investigate the application experiences and effectiveness of the infra-acetabular screw (IAS) placement technique in acetabular fracture surgery. MethodsA clinical data of 34 patients with complex acetabular fractures with anterior and posterior columns separation, who were admitted between January 2019 and October 2023 and treated with IAS fixation, was retrospectively analyzed. There were 23 males and 11 females with an average age of 55.3 years (range, 18-78 years). The acetabular fractures caused by traffic accident in 20 cases, falling from height in 12 cases, crushing injury in 1 case, and bruising with a heavy object in 1 case. According to the Letournel-Judet classification, there were 7 cases of anterior column fracture, 8 cases of anterior wall/column plus posterior hemi-transverse fracture, 2 cases of T-shaped fracture, and 17 cases of both-column fracture. The time from injury to surgery was 4-21 days (mean, 8.6 days). The time of IAS placement and the intraoperative blood loss were recorded. After surgery, the X-ray film and CT scan were re-examined, and the modified Matta score was used to assess the quality of fracture reduction. The trajectory of IAS in the channel was analyzed based on CT scan, and the screw length was measured. During follow-up, the fracture healing was observed and the hip function was assessed according to the modified Merle d’Aubigné-Postel scoring system at last follow-up. Results The IAS was successfully implanted in all 34 patients. The length of IAS ranged from 70 to 100 mm (mean, 86.2 mm). The time of IAS placement ranged from 10 to 40 minutes (mean, 20.7 minutes). The intraoperative blood loss ranged from 520 to 820 mL (mean, 716.8 mL). All patients were followed up 8-62 months (mean, 21.8 months). After surgery, 4 patients developed lateral femoral cutaneous nerve injury, 2 developed popliteal vein thrombosis of the lower extremity, 3 developed incision infection, and no surgical complication such as arteriovenous injury or obturator nerve palsy occurred. At last follow-up, the hip function was rated as excellent in 14 cases, good in 13 cases, fair in 4 cases, and poor in 3 cases according to the Merle d’Aubigné-Postel scoring system, with an excellent and good rate of 79.41%. Imaging re-examined showed that the quality of fracture reduction was rated as excellent in 9 cases, good in 19 cases, and poor in 6 cases according to the modified Matta score, with an excellent and good rate of 82.35%; and 25 (73.53%) IAS trajectories were located in the channel. All fractures obtained bony union, and the healing time was 12-24 weeks (mean, 18 weeks). During follow-up, there was no loosening or fracture of the plate and screws. Conclusion IAS placement technique can effectively strengthen internal fixation and prevent fracture re-displacement, making it a useful adjunct for treating complex acetabular fractures with anterior and posterior columns separation.