可吸收螺钉内固定+自体骨移植治疗新鲜舟状骨腰部骨折

1997年6月~2004年10月,我院采用可吸收螺钉内固定 自体骨移植治疗新鲜舟状骨腰部骨折18例,疗效满意。1材料与方法1.1病例资料本组18例,男15例,女3例,年龄15~41岁。左手6例,右手12例。致伤原因:各类训练伤3例,摔伤9例,车祸伤6例。骨折根据Coon-ey分型:稳定型10例,非稳定型(移位型)8例。受伤至手术时间3~19 d,平均5·1 d。1.2手术方法以桡骨茎突顶为中心,经鼻烟壶作5 cm纵形切口,保护头静脉和桡神经浅支,切除部分桡骨茎突。以腕关节桡偏时不再与腕舟骨骨折线相抵触为准,不可过分切除,否则会引起腕关节不稳定。切除的桡骨茎突可用于骨折断端间…     

A biomechanical comparison of scaphoid fixation with bone grafting using iliac bone or distal radius bone

PURPOSE: Although many scaphoid fractures may be treated by immobilization, complex scaphoid fractures generally require bone grafting with internal fixation. A preferred source of bone graft for scaphoid grafting is the iliac crest. Donor site morbidity from iliac crest harvest, however, is a known complication, and the comparable strength and osteogenic properties of bone harvested from other sites are unclear. To this end, we have conducted a cadaveric comparative investigation of the strength of scaphoid nonunions with bone graft and internal fixation using either iliac crest bone or distal radius bone. METHODS: Ten paired, human, fresh-frozen cadaveric wrists were used to create a standard midwaist wedge osteotomy into which identically shaped distal radius or iliac crest bone wedges were internally fixed using headless compression screws. After bone density and computed tomography assessment of the bones, benchtop biomechanical testing was conducted to compare the strength of the scaphoids after iliac and distal radius grafting, at 2-mm displacement, and at failure. RESULTS: Analysis of scaphoid length, width, height, weight, density, and screw placement revealed no statistical differences between both bone graft groups. Although not significant, scaphoid nonunions grafted with distal radius bone evidenced a reduced load (3.23 +/- 0.26 Nm) to 2-mm displacement compared with iliac crest bone (5.97 +/- 0.68 Nm). Similarly, though not significant, scaphoids grafted with distal radius bone showed a reduced load (4.18 +/- 0.30 Nm) to failure compared with iliac crest bone grafting (6.42 +/- 0.66 Nm). Although no significance was found between the 2 grafting methods, a trend toward greater strength in the iliac crest graft group was observed. CONCLUSIONS: Given the comparable biomechanical strength shown between iliac and distal radius bone in this study and the simplified surgical technique of distal radius harvesting, the data justify use of distal radius bone as a viable alternative donor source in scaphoid fracture treatment.     

可吸收螺钉治疗新鲜腕舟骨腰部不稳定性骨折

2006年10月～2008年10月,我院采用可吸收螺钉内固定治疗23例新鲜腕舟骨腰部不稳定性骨折,取得了很好的疗效。 1材料与方法 1．1病例资料本组23例,均为男性,年龄17～41岁。左手7例,右手16例,均为外伤所致腕舟骨骨折,且均为闭合性损伤。     

计算机辅助设计个体化经皮空心螺钉内固定治疗腕舟骨骨折的应用

目的利用Mimics软件设计一种腕舟骨骨折个体化掌侧经皮空心螺钉置钉技术。方法将24例成人腕舟骨骨折腕关节CT扫描数据导入Mimics软件,在Mimics软件中进行腕关节三维重建,模拟舟骨手术,制定舟骨个体化置钉参数并模拟置钉,据此参数在腕舟骨上经皮置钉。术后行腕关节CT扫描,验证置钉准确性。结果 Mimics重建图像和CT扫描的腕舟骨参数差异无统计学意义,能准确反映舟骨三维立体结构。用该方法对24例成人腕舟骨骨折行经皮空心螺钉固定,术后CT显示螺钉位置良好,随访腕关节功能良好。结论用Mimics软件对腕关节进行三维重建,模拟手术,测量、制订详细合理的个体化置钉参数,可优化手术方案与方式,减少并发症,降低手术风险,提高临床治疗效果。     

经皮腕背入路DTJ空心螺钉内固定治疗舟骨骨折

目的 总结经皮腕背人路DTJ空心螺钉内固定治疗舟骨骨折的经验.方法 利用经皮腕背人路DTJ空心螺钉内固定治疗舟骨骨折患者12例,男10例,女2例;年龄16~39岁,平均25岁.根据改良Herbert舟骨骨折分型:A2型3例,82型5例,83型2例,D1型2例.10例新鲜骨折患者自受伤至就诊时间为1~12d,平均3.5d;2例纤维愈合患者自受伤至就诊时间分别为76d和68d.结果 骨愈合时间为术后6.5~9.5周,平均8.5周.除1例患者行体力劳动后自觉有轻度腕痛外,其余11例患者术后疼痛均消失.患者均获得随访,随访时间6~26个月,平均14个月.12例患者术后患手握力恢复至健侧的平均86.4%(82%~93%),患侧腕关节屈伸活动度恢复至健侧的平均87.5%(83%~100%).除1例患者体力劳动后自觉有轻度腕痛改变原工作外,6例患者于术后平均5.5周(4.5~8周)返回原工作岗位,5例学生患者于术后平均4.5个月(3~6个月)恢复体育运动.所有患者腕背小切口均一期愈合,无感染等并发症发生.结论 经皮腕背入路DTJ空心螺钉内固定是一种微创、骨折愈合率高、并发症相对较少的舟骨骨折的有效治疗方法.     

The fixation strength of hydroxyapatite-coated Schanz screws and standard stainless steel Schanz screws in lower extremity lengthening

Introduction: Lengthening procedures are often complicated by loosening of pins. It has been reported that coating with hydroxyapatite improves fixation and reduces the rate of pin-track infection. Materials and Methods: We compared 47 hydroxyapatite-coated Schanz screws (HA screws) in 12 monolateral fixators mounted at the University Hospital Hamburg–Eppendorf with 45 standard stainless steel screws in 9 monolateral fixators mounted at the St Josefs-Hospital Wiesbaden by measuring the insertion and extraction torque values. The average implantation period was 7 months for the hydroxyapatite-coated screws and 5.4 months for the uncoated screws. We established the quotient of the maximum extraction torque over insertion torque which shows the change in the fixation strength with respect to time, the fixation index. It eliminates the influence of the varying pin–bone contact. Results: There was no significant difference in the rate of infection. In the Schanz screws without signs of infection the index was 1.92 for the HA screws and 0.76 for the stainless steel screws (P = 0.0002) giving evidence of the improvement of the fixation by the coating. Conclusion: HA coating resulted in improved fixation of Schanz screws in bone and may be useful in prolonged external fixation of the lower leg. The fixation index proved to be a simple tool for the evaluation of the fixation strength of Schanz screws.     

Technique of olecranon bone grafting for surgical fixation of scaphoid fractures

Currently described sources of bone graft, such as iliac crest and distal radius, for supplemental fixation of scaphoid fractures are suboptimal. In our experience, olecranon bone has the advantage of providing a convenient source of corticocancellous block graft that can be harvested within the same sterile operative field used for fixation of the scaphoid fracture, and it also causes less postoperative pain compared to that obtained from iliac crest. Here, we describe our surgical technique for harvest and use of olecranon bone graft for fixation of scaphoid fractures.     

Comparison of pullout strength of small-diameter cannulated and solid-core screws

The purpose of this study was to determine the difference in pullout strength between cannulated and solid-core small-diameter bone screws. Cannulated screws from different manufacturers were compared against solid-core screws with 2.0-mm, 2.4-/2.5-mm, and 3.0-mm diameters. A synthetic material made to simulate bicortical bone was used as the test medium. The screws were extracted under servohydraulic control. There was no statistically significant difference between any of the cannulated and solid-core 2.0-mm screws used in this study (P < .05). In the 2.4-/2.5-mm screw tests, both of the cannulated screw designs had a significantly higher pullout strength when compared with the solid-core screw (P < .05). In the testing of 3.0-mm screw test, 1 of the cannulated screw designs showed a significantly higher pullout strength than the other cannulated and solid-core screws that were tested (P < .05). The results of this study suggest that small-diameter cannulated bone screws are similar in mechanical pullout strength to solid-core screws.     

Percutaneous fixation of the scaphoid through a dorsal approach: an anatomic study

PURPOSE: Percutaneous surgical treatment of nondisplaced scaphoid fractures is becoming more common. Although the surgical anatomy at risk has been well described for the volar approach to the scaphoid, we have not found articles elucidating the dangers with a percutaneous dorsal approach. Additionally, direct placement of the screw is not possible with a percutaneous approach, and there is a risk of not seating the screw below the subchondral bone. The purpose of this study was to delineate the anatomy at risk using a dorsal percutaneous approach to the scaphoid and to determine the accuracy of using fluoroscopy to seat the screw flush with the subchondral surface. METHODS: Cannulated, headless screws were placed into the scaphoids of 12 fresh-frozen cadavers in standard percutaneous fashion through a dorsal approach. Fluoroscopy was used to seat the screw just below the subchondral surface. The wrists were then dissected and the distance from the guide wire to various anatomic structures was measured. The distance that the screw was protruding above or buried below the subchondral bone was also measured. RESULTS: The distances from the guide wire to the posterior interosseous nerve, to extensor digitorum communis to the index, and to extensor indicis proprius were 2.2 mm, 2.2 mm, and 3.1 mm, respectively. These structures were most at risk. The screw was prominent (above the subchondral bone) in 2 of 12 specimens and flush with or buried in the remaining 10 specimens. CONCLUSIONS: The results of this study show that there are anatomic structures at risk of injury with dorsal percutaneous placement of a headless screw into the scaphoid. Despite using live and static fluoroscopy views, we incorrectly placed the screw above the subchondral bone in 2 of the specimens. We support use of a limited incision when internally fixing a scaphoid from the dorsal approach.     

经皮穿刺中空加压螺钉固定治疗齿状突骨折

目的讨论经皮穿刺中空加压螺钉固定治疗齿状突骨折的临床效果。方法7例齿状突骨折采用牵引复位后,经皮穿刺单枚中空螺钉加压内固定治疗。结果7例均获随访,时间6～24(13±3.2)个月,骨折均愈合,临床症状消失。结论经皮穿刺单枚中空加压螺钉固定治疗齿状突骨折,临床疗效好;掌握好手术适应证、术前良好的复位是手术成功关键。     

通用型脊柱内固定系统椎弓根螺钉的生物力学测试

目的测试自行设计的通用型脊柱内固定系统(generalspinesystem,GSS)椎弓根螺钉以及SOCON和CCD螺钉置入正常成人椎体标本的最大轴向拔出力及最大旋入力矩,评价GSS螺钉对椎弓根的锚固作用。方法将27个正常成人腰椎椎体标本随机分为3组,每组9个椎体(18侧椎弓根),分别置入GSS、SOCON和CCD椎弓根螺钉,行螺钉拔出试验,测试并记录螺钉的最大旋入力矩和最大轴向拔出力。结果三组螺钉的最大旋入力矩分别为(1.83±0.27)Nm、(2.09±0.51)Nm和(1.66±0.34)Nm,最大轴向拔出力分别为(1131.0±255.4)N、(1034.0±262.3)N和(886.1±152.9)N。GSS螺钉最大轴向拔出力最大,且与CCD螺钉相比差异有非常显著性意义(P<0.01)。结论GSS螺钉具有很强的椎弓根锚固作用。     

通用型脊柱内固定系统椎弓根螺钉翻修作用的生物力学研究

目的测试自行设计的通用型脊柱内固定系统(generalspinesystem,GSS)椎弓根螺钉以及SOCON、TSRH和Diapason螺钉置入椎体的拔出力及旋入力矩,评价GSS螺钉的翻修作用。方法将36个正常成人腰椎椎体标本随机分为三组,每组12个椎体(24侧椎弓根)。各组标本每个椎体的每侧椎弓根均先拧入CCD螺钉(直径6.0mm,长45mm),行螺钉拔出试验,测试并记录螺钉的最大旋入力矩和最大轴向拔出力。然后各组标本每个椎体均随机选择一侧椎弓根经原钉道拧入GSS螺钉(直径6.5mm,长45mm);第一组另一侧拧入SOCON螺钉(直径7.0mm,长45mm),第二组另一侧拧入TSRH螺钉(直径7.0mm,长45mm),第三组另一侧拧入Diapason螺钉(直径6.7mm,长45mm)。分别测试螺钉最大旋入力矩及最大轴向拔出力。结果第一组GSS螺钉最大轴向拔出力为CCD螺钉的114%,SOCON螺钉为CCD螺钉的108%;GSS螺钉最大轴向拔出力大于SOCON螺钉,差异无显著性(P>0.05);GSS螺钉最大旋入力矩小于SOCON螺钉,差异无显著性(P>0.05)。第二组GSS螺钉最大轴向拔出力为CCD螺钉的127%,TSRH螺钉为CCD螺钉的64%;GSS螺钉最大轴向拔出力大于TSRH螺钉,差异有显著性(P<0.01);GSS螺钉最大旋入力矩大于TSRH螺钉,差异有显著性(P<0.01)。第三组GSS螺钉最大轴向拔出力为CCD螺钉的122%,Diapason螺钉为CCD螺钉的8     

Management of scaphoid nonunion

The primary risk factor for nonunion of the scaphoid is displacement/instability, but delayed or missed diagnosis, inadequate treatment, fracture location, and blood supply are also risk factors. Untreated nonunion leads to degenerative wrist arthritis-the so-called scaphoid nonunion advanced collapse wrist. However, the correlation of symptoms and disease is poor; the true "natural history" is debatable because we evaluate only symptomatic patients presenting for treatment. It is not clear that surgery can change the natural history, even if union is attained. The diagnosis of nonunion is made on radiographs, but computed tomography or magnetic resonance imaging scans can be useful to assess deformity and blood supply. Treatment options vary from percutaneous fixation to open reduction and internal fixation with vascularized or nonvascularized bone grafting to salvage procedures involving excision and/or arthrodesis of carpals.     

Evaluation of fixation of various screws in the lumbar vertebrae of dogs

Various screws for posterior fixation of the lumbar spine were evaluated for their firmness of fixation in mongrel dogs. Four types of screws: stainless steel, titanium base alloy, porous-coated, and hydroxyapatite-coated were inserted into vertebrae in dogs and examined for firmness of fixation in bone. Dogs were killed immediately and 2, 4, 6, and 8 weeks after insertion, and firmness of fixation was assessed by measuring the twisting force (i.e., the torque) required to loosen the screws. Also, the interface between screws and bone was histologically investigated. The hydroxyapatite-coated screws required the highest torque, compared with other screws, 2 weeks after insertion. At 8 weeks, the torque was 235% of that of the titanium alloy screws, indicating that the fixation of the hydroxyapatite-coated screws was highly stable. With the hydroxyapatite-coated screw, bone formed a direct bond with the hydroxyapatite, the connection to bone apparently being augmented with time. The results of these experiments suggest that the hydroxyapatite-coated screw has the advantage of firmer fixation in vertebrae over other conventional screws. A summary of this work was presented at the tenth annual Orthopaedic Research Meeting of the Japanese Orthopaedic Association at Karuizawa, Japan, in 1995     

Retrograde compression screw fixation of acute proximal pole scaphoid fractures

Seventeen consecutive patients with acute unstable proximal pole scaphoid fractures were managed over the past 5 years with open reduction and internal fixation. Four fractures were displaced, with greater than 1 mm of fragment offset and intercarpal malalignment. The operative technique consisted of a dorsal approach to the scaphoid, radius bone grafting, and freehand retrograde Herbert compression screw fixation. The patients were evaluated at an average of 37 months (range, 12-63 months) after surgery. All fractures healed within 13 weeks (average, 10 weeks). Functional wrist range of motion and grip strength were achieved in all patients. No patients developed osteonecrosis or radioscaphoid arthritis. Open reduction and internal fixation rather than primary casting is a better means of reducing the complications of delayed union, nonunion, and irreparable osteonecrosis that often occur after acute proximal pole scaphoid fracture treated with cast immobilization.     

Complications in dorsal percutaneous cannulated screw fixation of nondisplaced scaphoid waist fractures

PURPOSE: With advances in tools and techniques, percutaneous screw fixation of nondisplaced fractures of the scaphoid waist has gained increasing popularity in recent years as an alternative to prolonged cast immobilization or open reduction and internal fixation. Many reports cite low complication rates, including no complications in some series. The purpose of this study was to evaluate the complications encountered with dorsal percutaneous cannulated screw fixation of nondisplaced scaphoid waist fractures. METHODS: A retrospective chart review was performed for 24 patients who had surgery performed by a single surgeon over a 5-year period. All cases involved dorsal percutaneous cannulated screw fixation of nondisplaced (<1 mm) fractures of the scaphoid waist. Complications were rated a priori as major or minor based on modifications of established criteria. RESULTS: The overall complication rate was 29%; there were 21% (5/24) major complications and 8% (2/24) minor complications. Major complications consisted of 1 case of nonunion, 3 cases involving hardware problems, and 1 case of postoperative fracture of the proximal pole of the scaphoid. Minor complications included intraoperative equipment breakage-1 case involving a screw and 1 case involving a guide wire. CONCLUSIONS: Complications in dorsal percutaneous cannulated screw fixation of scaphoid fractures may be more common than previously reported.