Objective To compare the characteristics of gelatin microspheres crossl inked by glutaraldehyde (GA) or geni pin (GP). Methods Gelatin microspheres, prepared by the improved emulsified cold-condensation method, were crossl inked by GP and GA, respectively. After being dispersed in PBS, two kinds of microspheres with 60% degree of cross l inking were compared in terms of morphology, swell ing and degrading properties. rhBMP-2 were loaded into the GP and GAmicrospheres, and the encapsulation rate, drug loading and releasing capacity were measured; 100%, 50% and 25% leaching l iquid of GP and GA microspheres were respectively cultured with rat osteoblast (DMEM group as the control), and cell prol iferation was measured by MTT method to grade the cell cytotoxicity. Results GP and GA microspheres were both spherical with the diameters of (78 ± 18) μm and (65 ± 10) μm, and there were no difference between both microspheres in drug loading and encapsulation rate. But, GP microspheres, with long degrading period (28 days) compared to GA microspheres (21 days), had better dispersibil ity, and swell ing rate (89.0% ± 4.8%), the percentage of cumulative drug releasing at 10 days (78.80% ± 4.96%) were both lower than GA microsphere (118.0% ± 7.6%, 90.50% ± 5.12%). The percentages of drug loading of GP and GA were (921 ± 73) and (965 ± 62) ng/g, and the encapsulation rates were 88.5% ± 2.1% and 89.7% ± 1.8%; showing no significant difference (P gt; 0.05). The cell cytotoxicity of 100%, 50% and 25% leaching l iquid of GP microspheres was all at the level I, but leaching l iquid of GA microspheres with corresponding concentration were at the levels of III, III and II. Conclusion GP crossl inked gelatin microspheres are superior to GA crossl inked gelatin microspheres and can be widely used in tissue engineering field.
ObjectiveTo summarize the research progress in the lower limb lengthening by intramedullary nail. MethodsThe domestic and foreign related literature about the lower limb lengthening by intramedullary nail was reviewed, summarized, and analyzed. ResultsThe intramedullary nail lengthening systems can be divided into 3 types:distraction by mechanical strength, by motorized electronic power, or by motorized magnetic force. The new technology has obvious advantages in complication incidence, limb function, bone healing rate, comfortable and cosmetic degree of the patients, and hospitalization days compared with the external fixation, but it also has the disadvantages including lengthening failure of system breakdown, intramedullary infection, injuries of vessel and nerve, limited distraction length, and expensive price of the apparatus. And the method also has several contraindications:narrow medulla, multiple curves of medulla, osteomyelitis, skin infection, and unclosed epiphyseal plate. ConclusionThe lower limb lengthening by intramedullary nail is a major improvement of Ilizarov technology. Although the method has been used in limited cases, the preliminary clinical results are excellent, and it can be regarded as a new trend of the limb lengthening, bone reconstruction, and deformity correction.
Objective To investigate the effectiveness on the re-fracture of the femur with occult infection by using non-contact locking plate which was placed under the deep fascia. Methods Clinical data of 12 cases of occult infective re-fracture after femoral fracture operation were retrospectively analysed between January 2010 and December 2014. There were 8 males and 4 females with an age of 28-69 years (mean, 42.8 years). Femur re-fractured in 5 cases after 3 days to 4 weeks (mean, 10.6 days) of removal of internal fixation, including 4 cases of plate fixation and 1 case of intramedullary nail fixation; femur in 7 cases re-fractured because of breakage of internal fixator after 7-16 months (mean, 9.3 months) of internal fixation, including 5 cases of plate fixation and 2 cases of intramedullary nail fixation. The tissues near the fracture were collected for bacteria culturing and pathological examining. All the patients were treated by debriding the site of the fracture, bridging with the non-contact locking plate, and transplanting with granulated cancellous bone autograft. Intravenous infusion of antibiotics were used for 2-3 weeks after operation and oral administration for 4 weeks. The X-ray films were taken regularly and the function of the knees were evaluated by the Hospital for Special Surgery (HSS) score system. Results The results of bacteria culturing were positive in 8 patients and negative in 4 patients, and the pathological results of all the patients were confirmed to be chronic bone infection. All the fractures healed with no signs of exudation and ulceration of the incisions. The 12 patients were followed up 18-36 months (mean, 29.6 months). The fracture healed well and no re-fracture occurred. The fracture healing time was 14-22 weeks (mean, 18 weeks). At last follow-up, the function of the knee joint was excellent in 9 cases and good in 3 cases according to HSS score system. Conclusion The treatment of re-fractures after femur fracture operation needs to determine whether there is an occult infection, and non-contact locking plate placed under the deep fascia is an effective way for the re-fracture.
ObjectiveTo investigate the effectiveness on the distal radius deformity and bone defect after trauma by using Ilizarov external fixator.MethodsThe clinical data of 9 patients of post-traumatic distal radius deformity with bone defect treated by Ilizarov technique between January 2012 and December 2016 were retrospectively analyzed. There were 7 males and 2 females with an average age of 25.6 years (range, 11-46 years). Of the 9 cases, 4 were radial baseball hand deformity with large bone defect, 4 were short deformity of distal radius, 1 was distal radius deformity with radial deflection and pronation deformity, all with distal dislocation of the distant radial-ulnar joint. The time from injury to operation was 6 months to 6.2 years (mean, 1.5 years). The bone defect was 1.4-6.8 cm (mean, 3.6 cm). After complete debridement, the forearm was fixed with Ilizarov external fixator. At 7 days after operation, bone transport or bone lengthening was performed at the rate of 0.8-1 mm/d, 4 times a day, the deformity was slowly corrected and the bone defect was repaired. According to the loss of palmar tilt angle and ulnar tilt angle measured before operation, the position of distal radial articular surface was gradually adjusted in the course of moving or prolonging, so as to restore palmar tilt angle and ulnar tilt angle as far as possible.ResultsAll wounds healed by first intention and no leakage or rupture occurred. All the 9 patients were followed up 15-36 months (mean, 23 months). All the radius defects healed and the distal deformity was corrected, the healing time was 92.4-138.6 days (mean, 104.7 days); the external fixation index was 32.6-51.1 days/cm (mean, 40.2 days/cm). After 2 months of external fixator removal, the wrist joint flexion was (42.6±3.1)°, the wrist dorsum extension was (48.5±4.7)°, the palm inclination angle was (11.5±1.3)°, and the ulnar deviation angle was (21.2±3.7)°; the elbow flexion was (128.2±6.4)°, the elbow extension was (3.2±2.1)°, the forearm pronation was (71.5±4.3)°, and the forearm rotation was (38.2±6.5)°; the wrist and elbow joint extension and forearm rotation were significantly improved when compared with preoperative values (P<0.05). At last follow-up, wrist function was assessed according to Gartland-Werley standard, the results were excellent in 3 cases, good in 5 cases, and fair in 1 case. Four cases had pinhole infection, and were cured after anti inflammatory dressing change or replacement of needles; 3 cases did not heal at the bone junction, and were healed after bone grafting; 4 cases deviated from the radial force line, and the deformity was corrected after adjusting the needle.ConclusionIlizarov technique can correct deformity and reconstruct bone defect of the post-traumatic distal radius simultaneously, so it is a good method to treat this kind of disease.
ObjectiveTo investigate the feasibility of the anterolateral thigh free flap with the oblique branch in reconstructing the soft tissue defects of lower extremity. MethodsBetween June 2009 and February 2013,12 patients (including 7 males and 5 females) with soft tissue defects of lower extremity were treated with the anterolateral thigh free flap with the oblique branch,aged from 8 to 42 years (median,32 years).The locations of soft tissue defect were the dorsum of the foot in 5 cases,the ankle and foot in 4 cases,the lower leg in 2 cases,and the distal foot in 1 case.All defects were associated with exposure of tendon and bone.The size of the wound was from 15 cm×7 cm to 27 cm×12 cm.The interval of injury and operation was 1 to 7 days (mean,3.7 days).The anterolateral thigh flap was pedicled with only the oblique branch in 7 patients,and with the both descending branch and oblique branch in 5 patients,and the size of flap was from 17 cm×9 cm to 30 cm×15 cm.The donor sites were repaired by suture in 3 patients,and by skin graft in 9 patients. ResultsDistal skin flap necrosis occurred in 1 case,and was cured after dressing change and skin graft.The other flaps survived,and the donor site healed primarily.The follow-up time was from 10 months to 2 years (mean,18 months).Thinning operation was performed in 3 cases,and the other flaps recovered pain and warm sensation with good appearance. ConclusionIt is a safe and effective method to reconstruct soft tissue defects of the lower extremity with the anterolateral thigh flap pedicled with the oblique branch.
Objective To study the effect of dimethyloxalylglycine (DMOG) on angiogenesis in Choke Ⅱ zone of rats cross-zone perforator flaps and its mechanism. Methods One hundred and twenty-six adult male Sprague Dawley rats were randomly divided into DMOG group, YC-1 group, and control group, with 42 rats in each group. Cross-zone perforator flap model with size of 12 cm×3 cm was made on the back of rats in the three groups. DMOG group was intraperitoneally injected with DMOG (40 mg/kg) at 1 day before operation, 2 hours before operation, and 1, 2, and 3 days after operation; YC-1 group and control group were intraperitoneally injected with YC-1 (10 mg/kg) and the same amount of normal saline at the same time points, respectively. The survival of flap was observed after operation. At 7 days after operation, the survival area of flap in each group was measured and the survival rate of flap was calculated. Flap transmittance test, gelatin-lead oxide angiography, and HE staining were used to observed the angiogenesis in the Choke Ⅱ zone of flaps in each group. Immunohistochemical staining and Western blot were used to detect the expressions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1α (HIF-1α) in Choke Ⅱ zone of flaps in each group. The expressions of VEGF and HIF-1α were also determined by ELISA at 3, 5, and 7 days. Results At 7 days after operation, there was no obvious necrosis at the distal end of the flap in DMOG group, while necrosis occurred in both the control group and YC-1 group, mainly located at the distal end. The flap survival rate of DMOG group was 90.28%±1.37%, which was significantly higher than that of YC-1 group (84.28%±1.45%) and control group (85.83%±1.60%) (P<0.05). DMOG group had more angiogenesis in Choke Ⅱ zone and the vascular structure was clear and complete. In YC-1 group and control group, the vessels in Choke Ⅱ zone was less and the vascular structure was disordered. The number of vessels was (25.56±1.29)/field in the DMOG group, which was significantly higher than that in the YC-1 group [(7.38±0.54)/field] and the control group [(14.48±0.91)/field] (P<0.05). At 3, 5, and 7 days after operation, HIF-1α and VEGF expressions in ChokeⅡzone of DMOG group were significantly higher than those in YC-1 group and control group (P<0.05). ConclusionDMOG can promote angiogenesis in Choke Ⅱ zone, accelerate the early angiogenesis of the flap, improve the microcirculation and blood supply in the potential zone of the flap, reduce the injury of flap ischemia and hypoxia, and increase the survival rate of the flap.
Objective To evaluate the effectiveness of limited internal fixation combined with a hinged external fixator in the treatment of peri-elbow bone infection. Methods The clinical data of 19 patients with peri-elbow bone infection treated with limited internal fixation combined with a hinged external fixator between May 2018 and May 2021 were retrospectively analyzed. There were 15 males and 4 females with an average age of 44.6 years (range, 28-61 years). There were 13 cases of distal humerus fractures and 6 cases of proximal ulna fractures. All the 19 cases were infected after internal fixation of fracture, and 2 cases were complicated with radial nerve injury. According to Cierny-Mader anatomical classification, 11 cases were type Ⅱ, 6 cases were type Ⅲ, and 2 cases were type Ⅳ. The duration of bone infection was 1-3 years. After primary debridement, the bone defect was (3.04±0.28) cm, and the antibiotic bone cement was implanted into the defect area, and the external fixator was installed; 3 cases were repaired with latissimus dorsi myocutaneous flap, and 2 cases were repaired with lateral brachial fascial flap. Bone defects repair and reconstruction were performed after 6-8 weeks of infection control. The wound healing was observed, and white blood cell (WBC), erythrocyte sedimentation rate (ESR), and C-reaction protein (CRP) were reexamined regularly after operation to evaluate the infection control. X-ray films of the affected limb were taken regularly after operation to observe the bone healing in the defect area. At last follow-up, the flexion and extension range of motion and the total range of motion of the elbow joint were observed and recorded, and compared with those before operation, and the function of the elbow joint was evaluated by Mayo score. Results All patients were followed up 12-34 months (mean, 26.2 months). The wounds healed in 5 cases after skin flap repair. Two cases of recurrent infection were effectively controlled by debridement again and replacement of antibiotic bone cement. The infection control rate was 89.47% (17/19) in the first stage. Two patients with radial nerve injury had poor muscle strength of the affected limb, and the muscle strength of the affected limb recovered from grade Ⅲ to about grade Ⅳ after rehabilitation exercise. During the follow-up period, there was no complication such as incision ulceration, exudation, bone nonunion, infection recurrence, or infection in the bone harvesting area. Bone healing time ranged from 16 to 37 weeks, with an average of 24.2 weeks. WBC, ESR, CRP, PCT, and elbow flexion, extension, and total range of motions significantly improved at last follow-up (P<0.05). According to Mayo elbow scoring system, the results were excellent in 14 cases, good in 3 cases, and fair in 2 cases, and the excellent and good rate was 89.47%. ConclusionLimited internal fixation combined with a hinged external fixator in the treatment of the peri-elbow bone infection can effectively control infection and restore the function of the elbow joint.