摘要
Abstract
Objective: To study the biomechanical effects and the clinical outcome of different internal fixation methods in treating posterior malleolus fractures. Methods: (1 ) Biomechaniccal study of 18 pairs of posterior malleolus fracture models was conducted, in which all the cases were divided into 3 groups as Ⅰ ,Ⅱ and Ⅲ (n= 12) , according to different fracture degrees that included specimens with 1/4, 1/3 and 1/2 of articular facets fractured respectively; Each group was further divided into 2 subgroups as group A and group B. Group A was fixed with 2 steel half-thread tensile screws whose diameter was 4.0 mm; and group B was fixed with "T-shaped" steel distal-radius plates and 4 screws. The uploading experiment was carried out by settling the specimen on an experiment machine at its neutral position, and the data were collected and managed. (2) Clinical Applications; 31 cases with closed trimal-leolar fractures were treated from 2009.1 -2010. 12 in our hospital, in which 14 with posterior malleolus fractures≤25% of the capital diameter of the tibial plafond were fixed with screws, and 17 with posterior malleolus fractures＞25% of the capital diameter of the tibial plafond were fixed with steel plates. Prospective cohort study of these cases were carried out. The outcome was assessed using a Leeds Scoring System. Results: The mechanical fixation strengths of the plates for 1/4, 1/3 and 1/2 facets of posterior malleolus fractures were all higher than those of the screw groups [(4. 10 ±0. 13)kN vs. (4.60 ±0.27) kN, (3.20 ±0.12)kN vs. (4.12 ±0.14)kN and (1.98±0.18)kNi vs. (3.72 ±0.18)kN, respectively, P＜0. 05 ]. For the clinical study ,the mean follow-up period was 12 months (6-18 months) , all the cases acquired bone union, and the mean time for healing was 10 weeks (8-12 weeks). In the evaluation of therapeutic effects, we found that 28 cases were excellent and 3 good, which was 100% satisfying. Conclusion: If only 1/4 of the posterior articular facet is involved, 2 screws are enough to supply the stability; but for the fractures involve more than 1/4 facet, the plate fixation supplies more stable fixation and is superior to simply screws.关键词
踝关节/骨折/骨折固定术,内/生物力学Key words
Ankle joint/Fractures, bone/Fracture fixation, internal/Biomechanics分类
医药卫生
