To provide the scientific theoretical basis for cl inical practice by comparing biomechanicalcharacteristics of single compressed plate with intramedullary pin, locking intramedullary nail and simple arm externalfixator with simple internal fixation devices. Methods Eighteen wet humeral bone specimens of adult cadaver were madecompl icated fracture models of humeral shaft and divided into 3 groups according to fixation methods. Fracture was fixed by single compressed plate with intramedullary pin in plate group, by locking intramedullary nail in intramedullary nail group and by external fixator with simple internal fixation devices in external fixator group. The intensity and rigidity of compl icated fracture models of humeral shaft was measured in compress test and torsion test. Results In compress test, the maximum load in plate group (6 162.09 ± 521.06) N and in intramedullary nail group (6 738.32 ± 525.89) N was significantly larger than that in external fixator group (2 753.57 ± 185.59) N (P lt; 0.05); but there was no significant difference between plate group and intramedullary nail group (P gt; 0.05). Under 600 N physiological compress load, the rigidity was (171.69 ± 6.49) N/mm in plate group, (333.04 ± 36.85) N/mm in intramedullary nail group and (132.59 ± 2.93) N/mm in external fixator group; showing no significant difference between plate group and external fixator group (P gt; 0.05), and showing significant difference between intramedullary nail group and plate, external fixator groups (P lt; 0.05). In torsion test, the maximum torque in plate group (38.24 ± 7.08) Nm was significantly larger than those in intramedullary nail group (17.12 ± 5.73) Nm and external fixator group (20.26 ± 6.42) Nm (P lt; 0.05), but there was no significant difference between intramedullary nail group and external fixator group (P gt; 0.05). Under 0.80 Nm physiological torque, the rigidity was (16.36 ± 2.07) Ncm/° in plate group and (18.79 ± 2.62) Ncm/° in external fixator group, which was significantly larger than that in intramedullary nail group (11.45 ± 0.22) Ncm/° (P lt; 0.05); but there was no significant difference between plate group and external fixator group (P gt; 0.05). Conclusion Those fracture models fixed by single compressed plate with intramedullary pin have better compress and torsion intensity, they also have better torsion rigidity but less compress rigidity. Those fracture models fixed by locking intramedullary nail have better compress intensity but less torsion intensity, they also have better compress rigidity but less torsion rigidity. Those fracture models fixed by external fixator with simple internal fixation device have less compress and torsion intensity, they also have less compress rigidity but better torsion rigidity.
Objective To evaluate the safety of conversion from external fixation to internal fixation for open tibia fractures. Methods Between January 2010 and December 2014, 94 patients (98 limbs) with open tibia fractures were initially treated with external fixators at the first stage, and the clinical data were retrospectively analyzed. In 29 cases (31 limbs), the external fixators were changed to internal fixation for discomfort, pin tract response, Schantz pin loosening, delayed union or non-union after complete wound healing and normal or close to normal levels of erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and the leucocyte count as well as the neutrophil ratio (trial group); in 65 cases (67 limbs), the external fixators were used as the ultimate treatment in the control group. There was no significant difference in gender, age, side of the limbs, interval from injury to the first debridement, initial pathogenic bacteria, the limbs that skin grafting or flap transferring for skin and soft tissue defect between the two groups ( P>0.05). The incidence of Gustilo type III fractures in the control group was significantly higher than that in the trial group (P=0.000). The overall incidence of infection was calculated respectively in the two groups. The incidence of infection according to different fracture types and whether skin grafting or flap transferring was compared between the two groups. The information of the pathogenic bacteria was recorded in the infected patients, and it was compared with the results of the initial culture. The incidence of infection in the patients of the trial group using different internal fixation instruments was recorded. Results The overall incidences of infection for the trial and control groups were 9.7% (3/31) and 9.0% (6/67) respectively, showing no significant difference (χ2=0.013, P=0.909). No infection occurred in Gustilo type I and type II patients. The incidence of infection for Gustilo type IIIA patients in the trial group and the control group were 14.3% (1/7) and 6.3% (2/32) respectively, showing no significant difference (χ2=0.509, P=0.476); the incidence of infection for type IIIB patients in the two groups were 50.0% (2/4) and 14.3% (2/14) respectively, showing no significant difference (χ2=2.168, P=0.141); and the incidence of infection for type IIIC patients in the two groups were 0 and 16.7% (2/12) respectively, showing no significant difference (χ2=0.361, P=0.548). Of all the infected limbs, only 1 limb in the trial group had the same Staphylococcus Aureus as the result of the initial culture. In the patients who underwent skin grafting or flap transferring, the incidence of infection in the trial and control groups were 33.3% (2/6) and 13.3% (2/15) respectively, showing no significant difference (χ2=1.059, P=0.303). After conversion to internal fixation, no infection occurred in the cases that fixed with nails (11 limbs), and infection occurred in 4 of 20 limbs that fixed with plates, with an incidence of infection of 20%. Conclusion Conversion from external fixation to internal fixation for open tibia fractures is safe in most cases. However, for open tibia fractures with extensive and severe soft tissue injury, especially Gustilo type III patients who achieved wound heal after flap transfer or skin grafting, the choice of secondary conversion to internal fixation should carried out cautiously. Careful pre-operative evaluation of soft tissue status, cautious choice of fixation instrument and meticulous intra-operative soft tissue protection are essential for its safety.
Objective To investigate the effectiveness of arthroscopy-assisted combined fixation of Kirschner wire and external fixator for treating extreme distal radial fractures. Methods Between January 2014 and May 2016, 21 patients who suffered from extreme distal radial fractures were treated by arthroscopy-assisted combined fixation of Kirschner wire and external fixator. There were 14 males and 7 females with an age of 32-57 years (mean, 42.3 years). The causes of injury included falling in 13 cases and traffic accident in 8 cases. The fracture type included 8 cases of type 23C1, 9 cases of type 23C2, and 4 cases of type 23C3 according to AO/OTA classification. The time from injury to operation was 3-7 days (mean, 4.4 days). The Mayo score and disability of arm, shoulder, and hand (DASH) score were used to assess the pain and function of the wrist joint. Results There was no needle red swelling, tendon irritation, or orther early complications. All the patients were followed up 10-35 months (mean, 18.3 months). The fracture healing time was 9-13 weeks (mean, 10.6 weeks). At last follow-up, the Mayo score was 87-94 (mean, 90.9); and 17 cases were excellent and 4 were good. The DASH score was 7-13 (mean, 10.6). Conclusion Arthroscopy-assisted combined fixation of Kirschner wire and external fixator for treating extreme distal radial fractures has the advantages of firm fixation, early functional exercise, less postoperative complications, and good functional recovery of wrist joint.
ObjectiveTo review the research progress on correction of severe foot and ankle deformities with digital hexapod external fixators. Methods The relevant research literature on digital hexapod external fixators at home and abroad in recent years was reviewed and analyzed. Taking Taylor spatial frame (TSF) as a representative, this article elaborates on the research progress of this technology in the treatment of severe foot and ankle deformities from aspects such as device principle, technical characteristics, clinical application, complication management, and controversial perspectives, aiming to provide theoretical references for clinical application. Results The treatment of severe foot and ankle deformities is a complex challenge in orthopedics, often involving multiple plane alignment abnormalities, muscle weakness, soft tissue contractures, and joint dysfunction. The digital hexapod external fixators (such as TSF), based on the principle of six degrees of freedom motion and combined with computer-assisted technology, enables precise correction of multi-dimensional deformities. Conclusion The digital hexapod external fixators provides a minimally invasive and efficient option for the treatment of severe foot and ankle deformities, and shows significant advantages in the treatment of complex post-traumatic deformities, neuromuscular deformities, diabetes Charcot arthropathy, and other diseases.
ObjectiveTo explore the mechanical stability of the three-dimensional (3-D) external fixator for osteoporotic fracture so as to provide the biomechanical basis for clinical application. MethodsForty-five fresh frozen adult tibial specimens were selected to rapidly prepare the extracorporal tibia osteoporotic fracture models, and were randomly divided into 3 groups (n=15). Fractures were fixed with 3-D external fixators (3-D external fixators group), intramedullary nails (intramedullary nail group), and plate (plate group) respectively. Five specimens randomly from each group were used to do axial compression test, three-point bending test, and torsion test with microcomputer control electronic universal testing machine, then the mechanical parameters were calculated. ResultsIn the axial compression test, the displacement of 3-D external fixator group and intramedullary nail group were shorter than plate group, showing significant differences (P<0.05); but no significant difference was found between 3-D external fixator group and intramedullary nail group (P>0.05). In the three-point bending test and torsion test, the deflection and the torsional angle of 3-D external fixator group and intramedullary nail group were smaller than plate group, showing significant differences (P<0.05); but no significant difference was found between 3-D external fixator group and intramedullary nail group (P>0.05). ConclusionThe 3-D external fixator can fix fracture three-dimensionally from multiple plane and it can offer strong fixing. It is biomechanically demonstrated to be suitable for osteoporotic fracture.
ObjectiveThe anatomical calcaneal external fixator was designed by measuring and calculating the morphological data of the heel.MethodsA total of 100 normal people were randomly selected to obtain 200 hind foot data, including 45 males and 55 females, with an average age of 43.9 years (range, 19-67 years). According to the principles of human engineering and local anatomy, the morphological data of the heel in the weight-bearing standing position and supine position were measured with the direct measurement mode. The heel length, heel width, heel height, medial ankle height, lateral ankle height, and calcaneal pitch angle (CPA) were measured by vernier calipers and ulnar markers in weight-bearing standing position, and the gender groups and left and right foot groups were compared; the shape of the hind foot in the supine position was measured by three-dimensional (3D) dot matrix inverse model method. According to the stereoscopic data of the comprehensive anatomical morphology of the heel, the anatomical calcaneal external fixator was designed with AutoCAD 2019 and other 3D industrial design softwares.ResultsThe measurements of shoe size, heel length, heel width, heel height, medial ankle height, lateral ankle height, and CPA in male were significantly higher than those in female (P<0.05). There was no significant difference between the left and right feet in the other indexes except that the height of the medial malleolus of the left foot was significantly lower than that of the right foot (t=−2.827, P=0.005). The measurement of 3D dot matrix inverse model in supine position showed that the heel part was non-circular arc edge, and many groups of arc edges fluctuate in a limited range. Based on the above data, an anatomical calcaneal external fixator was designed, which could fit the anatomic radian in theory, so as to be flexible in configuration. On this basis, the ordinary configuration, compression configuration, and orthodontic configuration were designed to meet the treatment needs of calcaneal fractures in different degrees. The ordinary configuration was suitable for patients with Sanders Ⅰ, ⅡA, and ⅡB calcaneal fractures with no or slight displacement of intra-articular fractures; the ordinary configuration was mainly used for simple fixing. The compression configuration was suitable for patients with Sanders ⅡC, ⅢA, and ⅢB, tongue fractures, and avulsion fractures with severe displacement of intra-articular fractures; the compression configuration used obliquely drawn console wires to fix the displaced bones. The orthodontic configuration was suitable for patients with Sanders ⅢC and Ⅳ calcaneal fractures with severe displacement of intra-articular fractures or severe calcaneal bone defects; the orthodontic configuration was a multi-module design, which took into account the stable fixation of the fracture and the arbitrary adjustment of the joint fixation angle.ConclusionThe hind foot is special for morphology, so the external fixator designed based on the vernier caliper measurement method and 3D dot matrix measuring plate measurement method is an anatomical type and its configuration can theoretically meet stable and flexible clinical needs.
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.
Objective To investigate the effectiveness of hinged external fixator with mini-plate to treat terrible triad of the elbow. Methods Between August 2008 and June 2011, 11 patients with terrible triad of the elbow were treated with hinged external fixator combined with mini-plate. There were 9 males and 2 females, aged 22-56 years (mean, 34 years). The injuries were caused by falling from height in 8 cases and traffic accident in 3 cases. All patients were closed injury. The time from injury to operation varied from 8 hours to 7 days (mean, 3.7 days). According to Mason classification standard, all radial head fractures were type IV and complicated by posterior dislocation of the elbow; according to Regan-Morrey classification standard, ulna coronary process fractures were type I in 3 cases, type II in 3 cases, and type III in 5 cases. Results All the patients achieved primary healing of incision after operation and no nerve injury occurred. The patients were followed up 12-20 months (mean, 15 months). Two cases had screw channel infection after 12 weeks of operation, and 1 case had mild heterotopic ossification of the elbow after 4 months of operation. X-ray films showed that all fractures healed from 8 to 20 weeks (mean, 16 weeks). No recurrent dislocation or instability of the elbow occurred. At 12 months after operation, the elbow range of motion (ROM) were 120-145° (mean, 135°) in flexion, 0-25° (mean, 10°) in extension, 50-90° (mean, 70°) in pronation, and 50-80° (mean, 60°) in supination. According to Mayo elbow function evaluation standard, the results were excellent in 5 cases, good in 4 cases, and fair in 2 cases, with an excellent and good rate of 81.8%. Conclusion Hinged external fixator with mini-plate can enhance postoperative stability of the elbow. This therapy is beneficial to early functional exercise and obviously decrease the disability rate caused by complex damage on the elbow.
Objective To compare the effectiveness of suspension fixation plus hinged external fixator with double plate internal fixation in the treatment of type C humeral intercondylar fractures. Methods Between January 2014 and April 2016, 30 patients with type C (Association for the Study of Internal Fixation, AO/ASIF) humeral intercondylar fractures were treated. Kirschner wire suspension fixation plus hinged external fixator was used in 14 cases (group A), and double plate internal fixation in 16 cases (group B). There was no significant difference in gender, age, injury cause, disease duration, injury side, and type of fracture between 2 groups (P>0.05). Results There was no significant difference in operation time and hospitalization stay between 2 groups (P>0.05). But the intraoperative blood loss in group A was significantly less than that in group B (P<0.05); the visual analogue scale (VAS) score at 1 day and 3 days after operation in group A were significantly less than those in group B (P<0.05). Primary healing of incision was obtained in all patients of 2 groups, and no surgery-related complications occurred. The patients were followed up 6-24 months (mean, 12.3 months) in group A and 6-24 months (mean, 12.8 months) in group B. The self-evaluation satisfaction rate was 85.7% (12/14) in group A and was 81.2% (13/16) in group B at 3 months after operation, showing no significant difference (χ2=0.055, P=0.990). Based on the improved Gassebaum elbow performance score at 6 months after operation, excellent and good rate of the elbow function was 78.6% (excellent in 5 cases, good in 6 cases, fair in 2 cases, and poor in 1 case) in group A and was 81.2% (excellent in 6 cases, good in 7 cases, fair in 2 cases, and poor in 1 case) in group B, showing no significant difference between 2 groups (χ2=0.056, P=0.990). Heterotopic ossification occurred at 3 months after operation in 1 case of each group respectively. The X-ray films showed bony union in all cases; no loosening or breakage of screw was observed. The bone union time showed no significant difference between 2 groups (t=–0.028, P=0.978). The time of internal fixation removal, the intraoperative blood loss, and VAS score at 1 day and 3 days after operation in group A were significant better than those in group B (P<0.05). Conclusion The suspension fixation plus hinged external fixator and double plate internal fixation for the treatment of type C humeral intercondylar fractures have ideal outcome in elbow function. But the suspension fixation plus hinged external fixator is better than double plate internal fixation in intraoperative blood loss, postoperative VAS score, and time of internal fixation removal.
ObjectiveTo evaluate the mid-term effectiveness of arthrolysis and hinged external fixation for the treatment of stiff elbow caused by heterotrophic ossification.MethodsBetween January 2014 and December 2017, 11 patients with stiff elbow caused by heterotrophic ossification were admitted. There were 9 males and 2 females with an average age of 32 years (range, 14-48 years), and left side in 6 cases and right side in 5 cases. The cause of stiff elbow included humerus fracture in 5 cases, ulna fracture in 2 cases, fracture of capitulum radii in 1 case, dislocation of capitulum radii in 1 case, terrible triad of the elbow in 1 case, and soft tissue injury in 1 case. The disease duration ranged from 7 to 18 months (mean, 11 months). Preoperative active range of motion of elbow was (19.6±17.5)° and Mayo score was 34.1±9.7. All patients received the treatment of arthrolysis and debridement of heterotrophic ossification lesion combining hinged external fixator, and active and passive rehabilitation with the help of hinged external fixator. The hinged external fixators were removed after 2 months.ResultsAll patients were followed up 13-36 months (mean, 19.1 months). All incisions healed by first intention, and no complication of infection or nerve lesion occurred postoperatively. At last follow-up, the results of X-ray films showed that no heterotrophic ossification recurred. The active range of motion of elbow was (116.4±16.6)° and Mayo score was 93.2±7.8, showing significant differences when compared with preoperative ones (t=17.508, P=0.000; t=16.618, P=0.000).ConclusionThe application of arthrolysis and debridement of heterotrophic ossification lesion combining hinged external fixator can improve the elbow’s range of motion significantly and obtain a good mid-term effectiveness.