Objective To analyze the non-operation related risk factors of the wound complications by using lateral extensive L-shaped incision for open reduction and internal fixation of calcaneal fractures. Methods A retrospective analysis was made on the clinical data of 58 patients with closed calcaneal fractures (63 calcaneus) treated by using lateral intensive L-shaped incision for open reduction and internal fixation between September 2006 and August 2011. There were 52 males (56 calcaneus) and 6 females (7 calcaneus), aged 18 to 64 years (mean, 35 years). The causes of injury included fall injury in 53 cases (58 calcaneus), traffic injury in 5 cases (5 calcaneus). The mean time between injury and operation was 8 days (range, 3-22 days). According to Sanders classification, 4 calcaneus were rated as type II, 31 calcaneus as type III, and 28 calcaneus as type IV. Postoperative complications were observed and graded; 58 patients were divided into complication group (≥grade 2) and control group (lt; grade 2). The univariate analysis was used to analyze 18 factors which may lead to wound complications; multi-factor unconditioned logistic regression analysis was done for the factors showing significant difference. Results According to postoperative wound complications grading, 41 patients (46 calcaneus) were included in the control group, whose incision healed primarily, and 17 patients (17 calcaneus) in the complication group. In 17 patients of the complication group, 14 had skin necrosis or dehiscence, and 3 had superficial infection; they obtained healing after symptomatic treatment. The univariate analysis showed significant differences in combined spinal fracture, diabetes mellitus, and long-term smoking between 2 groups (P lt; 0.05). The logistic regression analysis revealed that combined spinal fracture was an independent risk factor for wound complications (95% confidence interval: 0.004-0.360, P=0.004). Conclusion Combined spinal fracture is an independent risk factor for wound complications after open reduction and internal fixation of calcaneal fracture using lateral extensive L-shaped incision.
Objective To investigate whether adding 1 transverse screw (TS) to the triangular parallel cannulated screw (TPCS) fixation has a mechanical stability advantage for Pauwels type Ⅲ femoral neck fractures by conducting finite element analysis on four internal fixation methods. Methods Based on CT data of a healthy adult male volunteer’s femur, three Pauwels type Ⅲ femoral neck fracture models (Pauwels angle 70°, Pauwels angle 80°, and Pauwels angle 70° combined with bone defect) were constructed using Mimics 21.0 software and SolidWorks 2017 software. Four different internal fixation models were built at the same time, including TPCS, TPCS+TS, three cross screws (TCS), and TPCS+medial buttress plate (MBP). The mechanical stability of different models under the same load was compared by finite element analysis. Results The femoral model established in this study exhibited a maximum stress of 28.62 MPa, with relatively higher stress concentrated in the femoral neck. These findings were comparable to previous studies, indicating that the constructed femoral finite element model was correct. The maximum stress of internal fixation in finite element analysis showed that TCS was the lowest and TPCS+MBP was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. The maximum displacement of internal fixation in each fracture model was located at the top of the femoral head, with TCS having the highest maximum displacement of the femur. The maximum stress of fracture surface in finite element analysis showed that TCS was the lowest and TPCS was the highest in the Pauwels angle 70° model, while TPCS+MBP was the lowest and TPCS/TCS were the highest in the Pauwels angle 80° model and the Pauwels angle 70° combined with bone defect model, respectively. The maximum displacement of fracture surfece analysis showed that TPCS+MBP was the lowest and TCS was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. Conclusion For Pauwels type Ⅲ femoral neck fractures, the biomechanical stability of TPCS+TS was superior to that of TPCS alone and TCS, but it has not yet reached the level of TPCS+MBP.