Guidelines for external fixation frame rigidity and stresses

Using results from FEM analyses and experiments as references, analytical methods are applied to develop simple approximate formulas to relate frame rigidity, maximal pin stresses, and peak pin-bone stresses in external fracture fixation (EFF) configurations in axial loading to the most important frame, pin, and bone parameters. It is found that, in a realistic range, the parameters can be adapted to vary the frame rigidity from about 13 N/mm to 17,000 N/mm, thereby reducing the maximal stresses in the pins and at the pin-bone interface by a factor of 140. In particular, when compromises have to be established in the frame characteristics in order to ensure a flexible configuration and limit the stress values at the same time, the formulas presented can provide useful guidelines. The side-bar separation and the pin modulus, in particular, can be adapted to decrease the rigidity, while only moderately increasing the stresses, thereby reducing changes for pin failure, pin-bone loosening, and pin-tract infection. A nomogram is presented for a quick reference to estimated relations between frame characteristics, rigidity, and stresses. It is believed that this material may be of use in EFF design and applications in clinical and animal experimental trials.     

经皮穿针和逆行髓内针固定治疗肱骨近端骨折

目的探讨经皮穿针和逆行髓内针固定治疗肱骨近端骨折的临床效果。方法1999年6月-2003年12月对29例肱骨近端骨折分别采用经皮穿针内固定21例，逆行髓内针固定5例，经皮穿针和逆行髓内针固定3例。结果术后无针眼感染、血管损伤、医源性桡神经损伤、螺纹针折断，未出现肱骨头坏死的征象。1例行经皮穿针内固定出现腋神经损伤症状，经治疗2个月后症状消失。29例术后8—12周骨折全部骨性愈合，无延迟愈合。术后3个月参照Neer肩关节百分评分标准，优10例，良15例，可3例，差1例，优良率为86．2％（25／29）。结论经皮穿针和逆行髓内针固定治疗效果满意，并发症发生率低，是治疗肱骨近端骨折的理想办法。     

Pelvic Ring Fractures: Utility of Clinical Examination in Patients with Impaired Consciousness or Tracheal Intubation

Abstract Objective: To define the diagnostic accuracy of clinical examination in patients with impaired consciousness or endotracheal intubation to detect pelvic ring fractures and to identify those with severe bleeding. Methods: Included in this prospective data collection with retrolective data analysis were a consecutive series of blunt trauma victims with either a Glasgow Coma Scale ≤ 13 or tracheal intubation. Clinical examination comprised testing for stability of the iliac wings. Results: From 784 subjects (injury severity score 23.3 ± 17.4) 93 patients (11.9%) were found to have a pelvic ring fracture. Clinical instability of the pelvic ring was found in 42 patients. There was only one false positive. Fifty-two fractures could not be identified by clinical examination, including nine fractures (17%) that required surgical fracture stabilization (sensitivity of clinical examination 44.1%). Seventeen fractures (18.3%) were associated with a blood loss larger than 20% of circulating blood volume. Sixteen of those were identified by clinical instability of the pelvic ring (sensitivity 94.1%, specificity 97.0%, positive predictive value 38.1%, negative predictive value 99.9%). Conclusions: Clinical examination for stability of the pelvis in this selected group of patients missed a significant number of pelvic ring fractures including fractures that require surgical stabilization. The finding of a clinically unstable identifies most of the patients with the pelvic ring fracture being a major source of bleeding. A stable pelvis makes pelvic ring fracture as being the source of bleeding quite unlikely.     

Lower limb blocks for children

Femoral and lateral cutaneous nerve of the thigh blocks have been performed in a group of 50 children; the method has not previously been described in paediatric practice. The technique was judged to have been successful in 48 (96%) of the children. There were no early or late complications. It is concluded that these blocks are easy to perform, even in small children and infants, and that they can produce reliable postoperative analgesia for a variety of orthopaedic and plastic procedures.     

头颈部肿瘤放疗对甲状腺功能的损伤

头颈部肿瘤放疗后会引起不同程度的甲状腺功能减退.引起甲状腺功能减退的机制包括射线对甲状腺及垂体细胞的直接损伤、对相关血管的损伤以及自身免疫反应等.影响头颈部肿瘤放疗后甲状腺功能的因素主要有:放疗剂量、放疗技术、是否联合手术化疗等.通过对这些影响因素的研究可为防治甲状腺功能减退提供依据,从而提高患者生活质量.     

股骨干粉碎性骨折的治疗

近年来随着交通运输业的发展,由于高能伤所导致创伤骨科中骨折粉碎程度愈来愈重,甚至使骨骼失去完整形态,尤其在股骨干部位,治疗极其困难,开放复位损伤大且达不到满意的固定,疗效不佳。我们最大限度地使用外固定器,很好地解决了这一难题,同样适用于肱骨和胫骨骨折。1临床资料本组12例,均为男性,年龄18~40岁,平均31.3岁。左侧5例,右侧7例。其中交通事故伤8例,高处坠落伤3例,摔伤1例。闭合伤10例,开放伤2例。骨折均为粉碎性,无软组织及血管神经损伤。2治疗方法患者麻醉后仰卧于骨科牵引手术床上,注意使患肢靠外,消毒铺巾后,保持下肢中立位轻度…     

高龄股骨转子间骨折两种治疗方法的临床观察

目的:探讨手术治疗高龄股骨转子间骨折的安全性、合理性。方法:股骨转子间骨折患者65例,其中采用动力髋螺钉(DHS)治疗32例,男14例,女18例;年龄65~79岁,平均(70.6±2.3)岁;EvansⅠ型2例,Ⅱ型7例,Ⅲ型15例,Ⅳ型8例。采用单边外固定支架治疗33例,男14例,女19例;年龄68~90岁,平均(74.2±3.8)岁;EvansⅠ型3例,Ⅱ型15例,Ⅲ型11例,Ⅳ型1例,Ⅴ型3例。临床观察包括术中出血量、手术时间、骨折愈合时间、术后并发症及髋部运动功能等。结果:所有病例均获随访,时间1~34个月,平均19个月。两组手术时间、术中出血量、术后并发症发生率差异有统计学意义(P<0.05)。平均愈合时间DHS组为(13.0±2.7)周,外固定支架组为(12.3±3.0)周,差异无统计学意义。Sanders髋关节功能评价:DHS组优19例,良6例,可3例,差2例;外固定支架组优12例,良8例,可8例,差5例。两组优良率差异有统计学意义(P<0.05)。结论:围手术期外固定支架组较DHS组安全简便,术后疗效DHS组优于外固定支架组。     

经肘外侧入路治疗Gartland Ⅲ型肱骨髁上骨折

1995年1月～2006年6月，我院采用肘外侧纵形切口、交叉克氏针内固定治疗Gartlandm型肱骨髁上骨折96例，取得较好效果。