Pedicle screw insertion: robotic assistance versus conventional C-arm fluoroscopy

Bone-mounted robotic guidance for pedicle screw placement has been recently introduced, aiming at increasing accuracy. The aim of this prospective study was to compare this novel approach with the conventional fluoroscopy assisted freehand technique (not the two- or three-dimensional fluoroscopy-based navigation). Two groups were compared: 11 patients, constituting the robotical group, were instrumented with 64 pedicle screws; 23 other patients, constituting the fluoroscopic group, were also instrumented with 64 pedicle screws. Screw position was assessed by two independent observers on postoperative CT-scans using the Rampersaud A to D classification. No neurological complications were noted. Grade A (totally within pedicle margins) accounted for 79% of the screws in the robotically assisted and for 83% of the screws in the fluoroscopic group respectively (p = 0.8). Grade C and D screws, considered as misplacements, accounted for 4.7% of all robotically inserted screws and 7.8% of the fluoroscopically inserted screws (p = 0.71). The current study did not allow to state that robotically assisted screw placement supersedes the conventional fluoroscopy assisted technique, although the literature is more optimistic about the former.     

The effect of C-arm malrotation on iliosacral screw placement

OBJECTIVES: We sought to determine whether inaccurate C-arm positioning could create images that lead to inaccurate interpretation of iliosacral screw positions. DESIGN: Cadaveric dissection study. SETTING: The learning institute of Zimmer Inc. in Warsaw, Indiana. METHODS: A laboratory investigation was performed using 3 nonpreserved cadaveric specimens. Several anatomic landmarks of the pelvis were outlined using radiographic markers and guide wires placed in several positions within the pelvis in each specimen. Using C-arm images we inserted the following: a "good" wire (GW), an out-the-front (OTF) wire, an out-the-back (OTB) wire placed into the sacral canal, an "in-out-in" (IOI) wire, and a wire in the S1 foramen (S1). The C-arm was then canted in 2-degree increments toward the head and then toward the feet starting from the optimum position. RESULTS: Properly positioned wires always appear to be contained within bone regardless of the amount of malrotation of the C-arm from the optimum inlet and outlet views. CONCLUSIONS: Improper malrotated fluoroscopic inlet and outlet views of the pelvis will distort the anatomic landmarks of the pelvis before improperly placed guide wires appear to be correctly placed. Properly placed guide wires will always appear correctly positioned regardless of the malrotation of the C-arm. "Malrotated" views, however, can be used to rule out certain incorrect screw positions.     

S2骶髂螺钉的置入技术

目的:介绍S₂骶髂螺钉的置入技术。方法:通过术前骨盆CT或标准骶骨侧位X线片测量确定S₂节段有足够的置钉空间。全麻后患者仰卧或俯卧,常规消毒铺巾。首先在标准骶骨侧位透视像监视下将导针尖确定在S₂神经根管前缘线、椎体前缘线及S₁骶前孔下缘三者所围成的区域内并打入髂骨外板1～2 mm,然后在骨盆出口位透视像监视下引导导针沿S₁骶前孔下缘及S₂骶前孔上缘之间的区域行进,在骨盆入口位透视像监视下确认导针位于S₂椎体及侧块前缘的后方,将导针打至合适长度,再次透视标准骶骨侧位像确认导针尖位于椎体前缘线后方及S₂骶神经根管前缘线的前方。之后沿导针测量长度,钻孔、攻丝后拧入骶髂螺钉。结果:应用此技术于不稳定型骨盆后环损伤患者27例,置入30枚S₂骶髂螺钉。经术后骨盆出入口位X线及CT检查确认所有螺钉均位于S₂椎体及侧块骨质内,置钉均准确。结论:S₂骶髂螺钉置入技术安全且可复制,可用于指导S₂骶髂螺钉的置入以增加不稳定型骨盆骨折后环固定的稳定性。     

Computer-guidance in percutaneous screw stabilization of the iliosacral joint

Nine patients with instability and one patient with degeneration of the iliosacral joint were treated surgically. The posterior pelvic ring was stabilized with the assistance of an optoelectronic navigation system. Registration was ensured by using fiducial screws in the iliac crest or by collecting landmarks on the external fixator. Computed tomography scans taken postoperatively provided additional information regarding implant localization in all patients. Accurate placement of 21 of 22 implanted iliosacral screws was observed. Two of the 21 screws touched the wall of the second sacral foramen without perforating the canal. One screw perforated the anterior wall of the sacrum because the navigated guide wire was bent during implantation. The initial results indicate that computer-aided frameless navigation in surgery of the iliosacral joint can facilitate surgical performance during screw stabilization in selected patients. Two important issues must be considered in the clinical application of this technique: first, any relative migration of the iliac and sacral bone structures between computed tomography scans taken preoperatively and intraoperative navigation may result in an intolerable inaccuracy of computer guidance. Second, bending of the guide wire of the tracked power drive, which cannot be accommodated by the navigation system, will lead to misguidance; therefore, only navigated drill sleeves should be used.     

Capture of the screw during percutaneous screw insertion

The simple technique to maintain the engagement of the screw and the screw driver during percutaneous locking screw insertion is presented. The method can capture the screw when the screw becomes disengaged. This will be helpful when percutaneous screw insertion is performed in the narrow and deep location of the bone such as a locking screw at the upper part of the femur during retrograde femoral nailing.     

前环皮下内置外固定架联合后环骶髂螺钉治疗不稳定骨盆骨折

目的评估应用前环皮下内置外固定架(internal fixation,INFIX)联合后环骶髂螺钉治疗不稳定骨盆骨折的临床疗效。方法2016年8月-2017年9月,采用前环皮下INFIX联合后环骶髂螺钉治疗不稳定骨盆骨折19例。其中男14例,女5例;年龄17~69岁,平均40.6岁。致伤原因:交通事故伤11例,高处坠落伤5例,重物砸伤3例。骨折根据Tile分型,B1型2例,B2型6例,C型11例。前环损伤包括双侧耻骨坐骨支骨折12例,单侧耻骨坐骨支骨折5例,耻骨联合分离2例;后环损伤包括骶髂韧带损伤2例,单侧髂骨骨折3例,单侧骶骨骨折11例,单侧骶髂关节脱位2例,双侧骶骨骨折1例。受伤至手术时间2~11 d,平均6.1 d。记录术中出血量及手术时间,观察骨折愈合情况及术后并发症情况。采用Matta评分标准评价骨折复位情况,采用Majeed评分标准评估患者术后功能。结果患者手术时间为47~123 min,平均61.4 min;术中出血量为50~115 mL,平均61.1 mL。术后1例发生植钉处切口浅表感染,1例发生单侧股外侧皮神经激惹,经相应处理后治愈或症状消失。无泌尿系统、生殖系统及肠道等损伤。所有患者均获随访,随访时间12~25个月,平均18.1个月。术后骨折均愈合,愈合时间8~13周,平均9.5周;无骨折不愈合、延迟愈合,内固定物松动、断裂等情况发生。2例术前腰骶丛神经损伤患者中,1例功能完全恢复,1例残留轻度跛行症状。末次随访时采用Matta评分标准评价骨折复位情况,获优13例、良6例,优良率100%;采用Majeed评分标准评价功能,获优15例、良4例,优良率100%。结论应用前环皮下INFIX联合后环骶髂螺钉治疗不稳定骨盆骨折临床疗效满意,并发症较少,是一种微创治疗骨盆环损伤的有效方法。     

Thoracic pedicle screw insertion in scoliosis using posteroanterior C-arm rotation method

OBJECTIVE: Previous researches have emphasized the importance and difficulties in accurate thoracic pedicle screw insertion in scoliosis patients. However, there has been no report on accuracy of the insertion using posteroanterior C-arm fluoroscopy rotated to allow en face visualization of the pedicle in humans. This study aimed to evaluate the accuracy of the thoracic pedicle screw insertion technique using a C-arm fluoroscopy rotation method for the treatment of scoliosis. METHODS: Between October 1997 and September 2005, 33 scoliosis patients who underwent surgical treatment with a total of 410 screws were analyzed. Eleven were male, 22 female and the mean age was 13.4 years. The mean preoperative Cobb angle was 59.7 degrees. Screws were inserted using the C-arm rotation method; screw positions were evaluated with postoperative computed tomography scans. RESULTS: The mean preoperative Cobb angle of 59.7 degrees was corrected to 18.9 degrees (range, 3 to 45 degrees) in the coronal plane (mean correction rate 68%). Postoperative computed tomography scans demonstrated 48 screws penetrated the medial (9 screws) or lateral (39 screws) pedicle cortex with a mean distance of 3.1 and 3.6 mm, respectively. No screws penetrated the inferior or superior cortex in the sagittal plane. CONCLUSIONS: Thoracic pedicle screw insertion in scoliosis patients using the posteroanterior C-arm rotation method allows en face visualization of both pedicles by rotating the C-arm to compensate for the rotational deformity, making it a practical, simple and safe method.     

骶髂螺钉固定在骶髂关节脱位中的应用解剖学研究

目的 :为应用骶髂螺钉固定骶髂关节脱位提供形态学依据。方法 :对 3 0具成人干燥骨盆标本 ,模拟骶髂螺钉内固定手术并作CT扫描 ,对进针点与不同解剖结构之间的距离、进针的方向、进针的深度以及S1骶孔上方的骶骨翼的前后径和上下径进行测量。结果 :进针点距臀肌线的距离为 ( 2 0 70± 3 2 7)mm ,距坐骨大切迹的距离为( 3 5 0 0± 1 91)mm ;轴位及冠状位CT测量进针与髂骨外板的交角分别为 ( 90 18± 2 69)°和 ( 90 40± 2 87)° ;进针深度为 ( 67 77± 3 63 )mm ;S1骶孔上方骶骨翼的前后径和上下径分别为 ( 18 2 6± 2 0 6)mm和 ( 18 74± 1 5 1)mm。结论 :临床应用骶髂螺钉固定需选择恰当的进针点和进针方向 ,术中需行骨盆正位、入口位和出口位的透视以确定螺钉植入的准确性     

CT引导下微创导向器在经皮骶髂关节螺钉固定中的初步应用

 目的 探讨CT引导下微创导向器辅助经皮骶髂关节螺钉固定的准确性。方法 2011年 1月至 5月, 采用 CT引导下微创导向器辅助经皮骶髂关节螺钉固定治疗骶髂关节骨折脱位患者 8例, 男 5例, 女 3例;年龄 26~56岁, 平均 32岁;均为垂直不稳定骨盆骨折。术前对 6例骶髂关节移位超过 2 cm的患者行股骨髁上骨牵引, 牵引重量为体重的 1/8~1/7。在 CT操作台的计算机屏幕上进行定位、测量最佳进针轨道后, 在患侧臀部标记定位。根据 CT扫描确定的进针角度调节导向器角度, 沿导向器前 端套筒打入克氏针, 并顺克氏针拧入 7.3 mm的空心螺钉。结果 8例患者均一次操作成功。手术时间 10~20 min, 平均 14 min。术后即刻行 CT扫描, 确认所有螺钉均位于术前预计的位置并完全位于骨内无 穿出, 骶髂关节形态恢复满意并得到确切固定。所有患者术中均未诉患侧下肢麻木或放射样疼痛, 术后患肢无一例发生血管、神经并发症。结论 导向器可避免 CT引导下骶髂关节螺钉固定时术者仅凭感觉判断进针角度而造成的偏差, 提高了CT引导下骶髂关节螺钉置入的准确性、安全性和简便性。     

肠道准备对经皮横向骶髂关节螺钉固定的影响

[目的]探讨肠道准备对经皮横向骶髂螺钉固定的影响。[方法]2015年8月~2018年12月,30例骶骨骨折行经皮横向S1骶髂关节螺钉置入治疗的患者纳入本研究,采用随机数字表法将患者分为两组,每组15例,准备组患者术前接受肠道准备,无准备组患者术前未接受肠道准备。比较两组手术时间、术中透视次数和曝光时间,以及影像测量的置钉偏差。[结果]准备组的手术时间显著短于无准备组,差异有统计学意义[(32.31±4.92)min vs(40.54±5.83)min,P<0.05)];准备组的术中X线暴露时间显著短于无准备组,差异有统计学意义[(62.59±5.79)s vs(83.19±6.41)s,P<0.05];准备组的术中透视次数显著少于无准备组,差异有统计学意义[(3.71±0.58)次vs(5.21±1.11)次,P<0.05]。术后CT三维重建测量螺钉与术前测量偏移方面,准备组的水平偏移小于无准备组,但差异无统计学意义[(5.53±2.21)°vs(5.63±1.97)°,P>0.05];准备组矢状位偏移小于无准备组,但差异无统计学意义[(4.32±2.08)°vs(4.52±1.91)°,P>0.05]。术后随访6~12个月,所有患者均未发生骶髂关节螺钉松动及断裂等并发症。[结论]肠道准备虽不能提高置钉准确率,但能够缩短手术时间和术中X线暴露时间。     

骶髂关节空心钉内固定导向器的研制及临床应用

目的 自行设计并研制一种骶骼关节空心钉内固定导向器,以期提高S1椎弓根空心钉置入的成功率及置入质量。方法 自行设计并研制的骶髂关节空心钉内固定导向器由带有测量长度的定位器、带有角度刻度表的水平面S1椎弓根空心钉置入角（TSA）、矢状面置入角(SSA)调节器及固定螺丝等组成。2006年6月至2009年10月共收治15例不稳定型骨盆骨折累及骶髂关节者,男6例,女9例;年龄19 ～ 60岁,平均45.6岁。不稳定型骨盆骨折经骶髂关节韧带3例,经骶骨Ⅰ区5例,累及骶骨Ⅱ区5例,累及骶骨Ⅲ区2例。15例患者均采用骶髂关节空心钉内固定导向器引导术中空心钉的操作,共置入18枚空心钉。结果 术后CT及X线片示18枚空心钉置入位置准确,与术前设计相比,具有相同或相近的TSA及SSA。结论 骶骼关节空心钉内固定导向器设计合理,使用方便,能提高S1椎弓根空心钉置入的准确性及置入质量,且可显著减少C型臂X线机的透视次数。     

C臂导航在胸腰椎椎弓根内固定术中应用

目的 探讨计算机导航技术在胸腰椎椎弓根内固定术中的应用价值.方法 在计算机导航下对15例胸腰椎疾患行胸腰椎椎弓根内固定术,术中共用72枚椎弓根螺钉固定.术后进行X线透视及CT平扫,用Richter分类法对螺钉固定位置进行评估.结果 所有病例全部在导航下完成,15例均获随访,时间6～24个月,无椎弓根螺钉松动及断裂.螺钉位置根据X线及CT复查结果,按Richter分类法进行评估:优68枚(94.4%),良4枚(5.6%).术中透视未发现螺钉突入椎管及穿出椎体外,未发生神经根、脊髓、血管损伤.术中C臂X线机透视的次数明显减少,手术时间缩短,手术成功率明显提高.结论 C臂导航能够明显减少胸腰椎椎弓根内固定术中的误差,提高手术的精确性.     

骶髂关节空心钉内固定导向器的研制及临床应用

目的自行设计并研制一种骶骼关节空心钉内固定导向器,以期提高S．椎弓根空心钉置入的成功率及置入质量。方法自行设计并研制的骶髂关节空心钉内固定导向器由带有测长度的定位器、带有角度刻度表的水平面S1椎弓根空心钉置入角（TSA）、矢状面置入角（SSA）调节器及固定螺丝组成。2006年6月至2009年10月共收治15例不稳定型骨盆骨折累及骶髂复合体,男6例,女9例;年龄19-60岁,平均45．6岁。不稳定型骨盆骨折经骶髂关节韧带3例,经骶骨Ⅰ区5例,累及骶骨Ⅱ区5例,累及骶骨Ⅲ区2例。15例患者均采用骶髂关节空心钉内固定导向器引导术中S1椎弓根空心钉的操作,共置入18枚S,椎弓根空心钉。结果术后CT及X线片示18枚S1椎弓根空心钉置入位置准确,与术前设计相比,具有相同或相近的TSA及SSA。结论骶骼关节空心钉内固定导向器设计合理,使用方便,能提高S1椎弓根空心钉置入的准确性,提高置入质量,且可显著减少X线机的透视次数。     

Electromyography monitoring for percutaneous placement of iliosacral screws

OBJECTIVE: To report our experience with the use of continuous electromyography (EMG) for placement of iliosacral screws. DATA SOURCES: Concurrently acquired data as well as patient charts, intraoperative EMG records, x-rays, and pelvic computed tomography (CT) scans. DESIGN: The monitored group of twenty-nine patients was studied prospectively. The control group consisted of twenty-two patients studied retrospectively. SETTING: Level One trauma center. METHODS: Continuous electromyograms were recorded for twenty-nine patients and compared with those from a group of twenty-two antecedent patients who were not monitored. The primary parameter of interest of this study was the presence or absence of neurologic change after iliosacral screw placement. This information was obtained prospectively in the study group and by retrospective review in the historical control. RESULTS: Four patients in the control group had postoperative and/or sensory motor changes prompting a postoperative CT scan; in each of these patients, a misdirected screw was identified and subsequently removed in a second procedure. There were no neurologic changes subsequent to placement in the twenty-nine patients who were monitored (7.5 percent versus 0 percent; p = 0.029, Fisher's exact test). All monitored patients had postoperative CT scans and showed the screw in a safe position with no significant violations of the S1 tunnel. CONCLUSION: Continuous EMG monitoring during iliosacral screw placement may be a useful neuroprotective tool.     

Technique for percutaneous insertion of intramedullary nail for intertrochanteric hip fracture

Intramedullary nailing has been proven to have biomechanical advantages over the use of a side plate and screw system. Further advantages may be gained with the use of a percutaneous technique, thereby minimizing blood loss, operative time, and overall morbidity. This article describes a technique for inserting an intramedullary nail percutaneously using a minimal-incision technique by utilizing fluoroscopy in cases of intertrochanteric hip fracture.