Vertically unstable pelvic fractures fixed with percutaneous iliosacral screws: does posterior injury pattern predict fixation failure?

OBJECTIVE: To measure the failure rate of percutaneous iliosacral screw fixation of vertically unstable pelvic fractures and particularly to test the hypothesis that fixations in which the posterior injury is a vertical fracture of the sacrum are more likely to fail than fixations with dislocations or fracture-dislocations of the sacroiliac joint. DESIGN: Retrospective review. SETTING: Level 1 trauma center. METHODS: All patients with pelvic fractures admitted between January 1, 1993, and December 31, 1998, were identified from the trauma registry. Hospital records were used to identify patients treated with iliosacral screws. Radiologic studies were examined to identify patients who had unequivocally vertically unstable pelvic fractures. Immediate postoperative and follow-up anteroposterior, inlet, and outlet radiographs from a minimum of 12 months postinjury were examined. Position, length, and numbers of iliosacral screws and any evidence of screw failure (eg, bending or breakage) were recorded. Residual postoperative displacement and late displacement of the posterior pelvis were measured. The main outcome measure was failure, defined as at least 1cm of combined vertical displacement of the posterior pelvis compared with immediate postoperative position. The main analysis was for association between fracture pattern and failure. Patient demographic data, iliosacral screw position, and anterior pelvic fixation method also were studied. RESULTS: The study group comprised 62 patients with unequivocally vertically unstable pelvic fractures in whom the posterior injury was treated with closed reduction and percutaneous iliosacral screw fixation. Of patients, 32 had dislocations or fracture-dislocations of the sacroiliac joint, and 30 had vertical fractures of the sacrum. Fixation failed in four patients, all with vertical sacral fractures and all within the first 3 weeks after surgery. These four patients required revision fixation. In two further cases with vertical sacral fractures, there was evidence that the fracture had only barely been held by the fixation, but these fractures healed, and follow-up radiographs did not meet the displacement criteria for failure. A vertical sacral fracture pattern was associated significantly with failure (Fisher exact test, P = 0.04); the excess risk of failure compared with sacroiliac joint injury was 13% (95% confidence interval 1% to 25%). There was no significant association between failure and anterior fixation method, iliosacral screw arrangement or length, or any demographic or injury variable. CONCLUSIONS: Percutaneous iliosacral screw fixation is a useful technique in the management of vertically unstable pelvic fractures, but a vertical sacral fracture should make the surgeon more wary of fixation failure and loss of reduction.     

Die triangul?re Osteosynthese instabiler Sakrumfrakturen

Zusammenfassung Operationsziel Stabile Sakrumosteosynthese mit exakter, vor allem vertikaler Reposition der Fragmente; Beseitigung einer Nervenwurzelkompression sowie frühzeitige Wiederherstellung einer schmerzfreien Funktion. Indikationen Alle vertikal instabilen Sakrumfrakturen vom Typ C der Beckenringbrüche. Auch Iliosakralfugensprengungen können mit dieser Osteosynthesetechnik behandelt werden. Begleitverletzungen sollten einer frühzeitigen Vollbelastung nicht im Wege stehen, da sonst der umfangreiche Eingriff mit eigener Morbidität nicht gerechtfertigt ist. Kontraindikationen Offene Frakturen, Décollement des hinteren Beckenringes oder Frakturen mit erheblicher Weichteilbeteiligung in der Akutphase wegen der Gefahr von Infektionen und Weichteildefekten. Operationstechnik Frakturreposition durch dorsalen, bogenförmigen oder paravertebralen Zugang. Vertebropelvine Abstützung zwischen Pedikel L4 oder L5 und hinterem Os ilium oder Ala sacralis lateral der Sakrumfraktur. Nachfolgende horizontale Stabilisierung durch iliosakrale Verschraubung (einseitige Frakturen mit geringer Dislokation) oder transsakrale Plattenosteosynthese (bilaterale Frakturen, einseitige Frakturen mit ausgepräger Dislokation). Bei Stabilisierung des vorderen Beckenringes reicht eine iliosakrale Schraube aus; sonst müssen zwei Iliosakralschrauben gesetzt werden. Der vordere Beckenring wird nur bei Symphysenrupturen, ausgeprägter Dislokation oder im Fall von Begleitverletzungen, die einen ventralen Zugang erfordern, angegangen. Ergebnisse Zwischen April 1992 und März 1998 wurden 48 Patienten im Durchschnittsalter von 34 (15 bis 72) Jahren mit vertikal instabilen Sakrumfrakturen auf die beschriebene Weise stabilisiert. Seit 1994 wurde eine postoperative Vollbelastung zunehmend früher erlaubt. Trotz sofortiger postoperativer Vollbelastung kam es bei korrekter triangulärer Osteosynthese zu keimen Repositionsverlust - drei Patienten mit Repositionsverlust wiesen eine unvollständige Frakturreposition und eine ungenügende operative trianguläre Stabilisierung auf. Weichteilprobleme können bei Patienten mit nicht versenkt eingebrachter Pedikelschraube im hinteren Beckenkamm auftreten. Alle Frakturen heilten ohne Pseudarthrosenbildung aus. Das Osteosynthesematerial wurde bei 23 Patienten entfernt, bei einem Patienten wegen einer tiefen Wundinfektion und bei 22 nach Ausheilen der Fraktur. Von 25 Patienten mit präoperativem neurologischen Defizit zeigten vier eine vollständige und drei eine teilweise Remission. Summary Objectives Stable internal fixation of sacral fractures after anatomic reduction of the vertical displacement. Decompression of nerve roots. Early return to pain-free function. Indications All vertically unstable sacral fractures of type C pelvic ring disruptions. Sacroiliac dislocations. Contraindications Compound fractures. Soft tissue detachment of posterior pelvic ring or fractures associated with considerable soft tissue trauma constitute a contraindication limited to the immediate post-injury phase given the risk of infection and soft tissue complications. Surgical Technique Curvilinear or paravertebral posterior approach. Reduction of the fracture, stabilization between pedicle of L4 or L5 and posterior aspect of the iliac bone or the sacral wing lateral to the sacral fracture. Thereafter, iliosacral screw fixation (unilateral fractures with little displacement) or transsacral plate fixation (bilateral fractures or unilateral fractures with marked displacement). If a stabilization of the anterior pelvic ring has been performed, 1 iliosacral screw is sufficient, otherwise 2 screws should be used. Stabilization of the anterior pelvic ring is only indicated in the presence of disruption of the symphysis, marked displacment of fragments, or if associated injuries necessitate an anterior approach. Results Since April 1992, vertically unstable sacral fractures were treated with this stabilization in 48 patients (average age 34 years, range 15 to 72 years). Since 1994, the start of postoperative full weight-bearing was gradually advanced. Despite the immediate postoperative full weight bearing, a loss of reduction was not observed in properly performed triangular internal fixation. An imcomplete reduction associated with an inadequate stabilization led to a loss of correction in 3 patients. Prominent heads of pedicle screws at the level of the posterior iliac crest may cause soft tissue problems. All fractures consolidated. Implant removal was performed in 23 patients, in 1 patient on account of deep infection and in 22 after consolidation of the fracture. Out of 25 patients with preoperative neurologic deficit, 4 showed a complete and 3 a partial recovery.     

Fixation of posterior pelvic ring disruptions through a posterior approach

Objective  Stable internal screw fixation of posterior pelvic ring disruptions through a posterior approach. Indications  Complete, unstable sacroiliac dislocations with incompetence of anterior and posterior sacroiliac ligaments. Sacroiliac fracture dislocations. Displaced vertical sacral fractures. Contraindications  Damage to posterior soft tissues. Acceptable closed reduction of sacrum or sacroiliac joint. Ipsilateral acetabular fractures treated through an anterior approach. Inadequate intraoperative fluoroscopic visualization of posterior pelvis. Surgical Technique  Vertical paramedian incision overlying the sacroiliac joint. Release of origin of gluteus maximus. Inspection and reduction of sacroiliac joint. Stabilization with iliosacral screws under image intensification. Secure repair of gluteal fascia. Results  107 patients with unstable pelvic ring fractures were treated with open reduction and internal fixation of which 83 had an open reduction of posterior ring injuries. Accuracy of reduction: more than 95% of patients had residual displacement of less than 10 mm. Two patients had a deep wound infection postoperatively. Two-thirds of the patients were able to resume their previous occupation. Pain was either absent or occurred only with strenuous activities. 63% had a normal gait.     

Unilaterale trianguläre lumbopelvine Stabilisierung

Operative fixation has become treatment of choice for unstable sacral fractures. Osteosynthesis for these fractures results in loss of reduction in up to 15%. Vertical sacral fractures involving the S1 facet joint (Isler 2 and 3) may lead to multidirectional instability. Multidirectional instability of the posterior pelvic ring and lumbopelvic junction may be stabilized and forces balanced by a so-called lumbopelvic triangular fixation. Lumbopelvic triangular fixation combines vertical fixation between the lumbar vertebral pedicle and the ilium, with horizontal fixation, as an iliosacral screw or a transiliacal plate osteosynthesis. The iliac screw is directed from the posterior superior iliac spine (PSIS) to the anterior inferior iliac spine (AIIS). Thereby, lumbopelvic fixation decreases the load to the sacrum and SI joint and transfers axial loads from the lumbar spine directly onto the ilium. Triangular lumbopelvic fixation allows early full weight bearing and therefore reduces prolonged immobilization. The placement of iliac screws may be a complex surgical procedure. Thus, the technique requires thorough surgical preparation and operative logistics. Wound-related complications may occur. Preexisting Morell–Lavalée lesions increase the risk for infection. Prominent implants cause local irritation and pain. Hardware prominence and pain are markedly reduced with screw head recession into the PSIS.     

Zugangs- und Lagerungswahl bei operativer Behandlung von Beckenverletzungen

Surgical treatment of pelvic ring injuries requires in-depth knowledge of the topographic anatomy of the pelvic bones, joints and soft tissue structures. A wide range of stabilizing techniques is available including bridging plate osteosynthesis, iliosacral compression screw osteosynthesis and transpubic positioning screws. In this article the different treatment strategies with the respective surgical approaches and patient positioning for pelvic ring fractures and combined lesions of the pelvic ring and acetabulum are presented. Pelvic ring lesions with rotational instability are approached from the anterior and occasionally from both the anterior and posterior based on the amount and localization of the instability. In vertically unstable lesions the most unstable part must be addressed first by reduction and fixation of the dislocated part to the axial skeleton. In combined fractures of the pelvis and acetabulum dorsal stabilization is carried out first.     

S1 pediculoiliac screw fixation in instabilities of the sacroiliac complex: biomechanical study and report of two cases

OBJECTIVE: A new technique for posterior sacroiliac fixation is described and compared with conventional techniques. PATIENTS/MATERIAL AND METHODS: A patient with sacral alar fracture (zone 1) and another one with sacroiliac joint instability due to tuberculous infection underwent fixation using screws placed in the S1 pedicle and the iliac bone. Vertical stability of the new technique also was investigated using polyurethane pelvic bone analogs and compared with anterior double plating (group P) and iliosacral screw fixation (group ISS) techniques. RESULTS: Healing was obtained and reduction was maintained in both patients on the final follow-up examination at 2 years postoperatively. Vertical loading tests revealed that failure loads within the first 10 mm of displacement of the new pediculoiliac screw fixation technique (group PIS) was higher than plating (P = 0.03) and lower than ISS techniques (P = 0.002). Ultimate failure load of the PIS technique was slightly higher than plating (P = 0.277) and lower than ISS techniques (P = 0.003). With the addition of an iliosacral screw to the pediculoiliac screw construction (PIS+ISS), the PIS technique became more stable in early (P = 0.110) and ultimate failure loads (P = 0.003). CONCLUSIONS: Pediculoiliac screw fixation for sacroiliac joint disruptions and zone I sacrum fractures using iliac and S1 pedicle screws is a new and effective alternative for obtaining and maintaining anatomic reduction.     

S1椎弓根螺钉结合髂骨板间螺钉治疗骶髂关节骨折脱位

目的 探索S1椎弓根螺钉结合髂骨板问螺钉治疗骶髂关节骨折脱位的临床疗效，评价两者结合对骶髂关节骨折脱位的治疗价值。方法 对11例骶髂关节骨折脱位患者用脊柱内固定系统(TSRH)之S1椎弓根螺钉结合髂骨板间螺钉进行固定，该组患者涉及骶髂关节的垂直移位及旋转的骨盆环变形，归于Tile分型的B类或C类骨盆损伤。11例患者均伴有前环损伤，其中9例予以加压钢板(smith nephew)内固定，余2例患者单纯采用后路手术内固定。结果 7例患者垂直移位完全复位，9例旋转畸形纠正，未发现感染及神经损伤等并发症。结论 S1椎弓根螺钉结合髂骨板问螺钉固定技术治疗骶髂关节骨折脱位，可获得即刻稳定性并良好地维持了复位的效果．这一混合技术对于涉及垂直及旋转损伤的骨盆环损伤有稳定的作用。     

有限切开内固定结合外固定器治疗Tile C型骨盆骨折

目的 探讨有限切开内固定结合外固定器治疗Tile C型骨盆骨折的临床价值.方法 采用有限切开内固定结合外固定器治疗Tile C型骨盆骨折28例,男17例,女11例;年龄21~52岁,平均34岁;合并神经损伤4例,失血性休克16例,其他部位骨折15例.按照Tile分型均为C型骨折,C1型15例,C2型9例,C3型4例.结果 28例中,23例复位满意,5例未完全复位,其中3例纵向移位≥1cm,2例横向分离移位(耻骨联合分离≥2cm,耻骨支分离≥1cm).骨折愈合时间2~5个月,平均3.2个月.2例切开复位后骶髂部皮肤发生浅层感染,培养为表皮葡萄球菌,选用敏感抗生素治疗后感染得到控制.3例外固定针孔感染.1例骶髂螺钉固定术后CT证实螺钉穿出S1A椎体前皮质.1例外固定支架固定螺钉穿出髂嵴外侧皮质.1例术后股外侧皮神经损伤.26例获得随访,随访时间18~58个月,平均48个月.根据Majeed制定评估标准,优17例,良7例,可2例,优良率92.3%.4例术前有神经损伤症状者,2例在术后4个月时完全恢复,2例未恢复.4例患者主诉腰骶部疼痛.结论 有限切开内固定可纠正不稳定骨盆骨折纵向移位,而横向移位可以使用外固定器复位固定.     

骶髂螺钉固定治疗垂直不稳定骨盆后环骨折的疗效分析

目的评价骶髂螺钉治疗不稳定型骨盆骨折的临床疗效。方法采用骶髂螺钉治疗42例不稳定型骨盆骨折。应用Tornetta复位情况评价表评估复位情况,应用Majeed骨盆骨折评分系统评价疗效。结果 42例均获随访,随访时间为4~34个月,平均15个月。闭合复位骶骨钉内固定骨盆骨折后环不稳术后分疗效满意。结论掌握骶骨置钉技巧,应用骶骨钉固定骨盆骨折后环不稳,手术操作简单、疗效好、适于基层医院广泛开展。     

Transiliac-transsacral screws for posterior pelvic stabilization

Typical posterior pelvic fixation constructs use one or more large screws inserted from the lateral iliac cortex into the safe upper sacral ala or body. As a result of the deforming forces acting perpendicular to the implant axis, routine iliosacral screw fixation may not provide adequate stabilization, especially in certain unstable injuries. Longer iliosacral screws that traverse the entire upper sacrum and exit the contralateral iliac cortex may improve holding power and also stabilize concomitant contralateral posterior pelvic injuries. These transiliac-transsacral screws are reliably safe to insert using routine intraoperative fluoroscopy, and they provide durable fixation. These screws require careful preoperative planning and more precise technical attention during insertion because they pass through both sacral alar zones. Transiliac-transsacral screws may be particularly useful in the presence of osteoporosis, significant posterior pelvic instability including spinopelvic dissociation, patient obesity, anticipated noncompliant behavior, bilateral posterior pelvic injuries, and nonunion procedures.     

Pseudoaneurysm of the superior gluteal artery during iliosacral screw fixation

We present a case of a pseudoaneurysm of the superior gluteal artery following placement of an iliosacral screw in a patient with an unstable pelvic ring fracture. Percutaneous fixation of posterior pelvic ring injuries is becoming a popular method for pelvic stabilization. Several techniques are available t achieve stability and allow early mobilization in patients with displaced pelvic fractures. Percutaneous screw fixation of sacral fractures or sacroiliac joint disruptions should reduce operative and anaesthesia times as well as blood loss, while lowering the risk of surgical wound problems are decreased. The risks with this technique are generally iatrogenic, related with surgeon's lack of experience or imaging difficulties at the time of screw placement. The present case report describes an injury to the superior gluteal arterial system during percutaneous iliosacral screw insertion.     

Biomechanical comparison of posterior pelvic ring fixation

OBJECTIVE: To determine relative stiffness of various methods of posterior pelvic ring internal fixation. DESIGN: Simulated single leg stance loading of OTA 61-Cl.2, a2 fracture model (unilateral sacroiliac joint disruption and pubic symphysis diastasis). SETTING: Orthopaedic biomechanic laboratory. OUTCOME VARIABLES: Pubic symphysis gapping, sacroiliac joint gapping, hemipelvis coronal plane rotation. METHODS: Nine different posterior pelvic ring fixation methods were tested on each of six hard plastic pelvic models. Pubic symphysis was plated. The pelvic ring was loaded to 1000N. RESULTS: All data were normalized to values obtained with posterior fixation with a single iliosacral screw. The types of fixation could be grouped into three categories based on relative stiffness of fixation: For sacroiliac joint gapping, group 1-fixation stiffness 0.8 and above (least stiff) includes a single iliosacral screw (conditions A and J), an isolated tension band plate (condition F), and two sacral bars (condition H); group 2-fixation stiffness 0.6 to 0.8 (intermediate stiffness) includes a tension band plate and an iliosacral screw (condition E), one or two sacral bars in combination with an iliosacral screw (conditions G and I); group 3-fixation stiffness 0.6 and below (greatest stiffness) includes two anterior sacroiliac plates (condition D), two iliosacral screws (condition B), and two anterior sacroiliac plates and an iliosacral screw (condition C). For sacroiliac joint rotation, group 1-fixation stiffness 0.8 and above includes a single iliosacral screw (conditions A and J), two anterior sacroiliac plates (condition D), a tension band plate in isolation or in combination with an iliosacral screw (conditions E and F), and two sacral bars (condition H); group 2-fixation stiffness 0.6 to 0.8 (intermediate level of instability) includes either one or two sacral bars in combination with an iliosacral screw (conditions G and I); group 3-fixation stiffness 0.6 and below (stiffest fixation) consists of two iliosacral screws (condition B) and two anterior sacroiliac plates and an iliosacral screw (condition C). DISCUSSION: Under conditions of maximal instability with similar material properties between specimens, differences in stiffness of posterior pelvic ring fixation can be demonstrated. The choice of which method to use is multifactorial.     

骶髂关节经皮拉力螺钉固定钉道参数的解剖学测量

目的 为经S_1椎弓根水平骶髂关节拉力螺钉固定术提供应用解剖学依据.方法 2008年6月至2009年7月收集50个成人骨盆的螺旋CT扫描数据,重建骨盆三维模型,模拟经皮托力螺钉固定.测量S_1椎弓根的宽和高、骶髂关节拉力螺钉的进针点和进针方向、进针点至S_1椎体对侧前皮质和髂后上棘的距离.结果 S_1椎弓根的宽和高分别为(20.43±1.63)mm和(20.26±0.99)mm;2枚螺钉的进针点均在髂前上棘和髂后上棘的连线上方,至髂后上棘的距离分别为(49.87±6.80)mm和(51.11±7.15)mm.螺钉平行进入S_1椎弓根,与髂骨翼后外侧面垂直,与冠状面和欠状面的夹角分别为18.35°±5.20°和77.62°±3.98°.进针点到S1椎体对侧前皮质的距离分别为(76.08±4.32)mm和(77.62±3.98)mm.骶髂关节拉力螺钉的长度、S_1椎弓根的高度和宽度、进针点到髂后上棘的距离、进针点与冠状面的夹角在男女之间差异有统计学意义(P<0.05).结论 正常成人在S_1椎弓根水平均町置入2枚直径为6.5 mm的拉力螺钉,钉道参数的解剖学测量为骶髂关节拉力螺钉固定手术导航模板的设计提供了理论基础.     

Percutaneous stabilization of U-shaped sacral fractures using iliosacral screws: technique and early results

PURPOSE: To present the technique and early results of percutaneous stabilization of U-shaped sacral fractures with attention to neurologic recovery and maintenance of fracture reduction of the sacrum. DESIGN: Retrospective clinical study. SETTING: Level I trauma center. PATIENTS: During a thirty-eight-month period, 442 patients with pelvic ring disruptions were treated at a Level I trauma center. Thirteen (2.9 percent) of these patients had displaced U-shaped sacral fractures treated with percutaneous stabilization. INTERVENTION: Fracture stabilization was accomplished using fluoroscopically guided iliosacral screws inserted percutaneously with the patient positioned supine. Neurodiagnostic monitoring was not used during screw insertions. This technique was limited to patients with sacral kyphotic deformities, which allowed in situ fixation. Sacral neurologic decompression was not performed. MAIN OUTCOME MEASUREMENTS: Fracture healing and the stability of fixation were assessed on inlet and outlet radiographs and a lateral sacral view. Detailed neurologic examinations were performed at injury and at follow-up. RESULTS: The sacral fractures were classified based on plain pelvic radiographs and computed tomography scans and included one Type 1, eight Type 2, and four Type 3 fracture patterns. Twenty-five fully threaded cancellous 7.0-millimeter cannulated screws were used. Eleven patients had bilateral screw fixations; one patient had unilateral double screw fixation; and one patient had unilateral single screw fixation. Operative time for screw insertion averaged forty-eight minutes, with 2.1 minutes of fluoroscopy per screw. Accurate screw insertions without neuroforaminal or sacral spinal canal violations were confirmed in all patients with postoperative pelvic plain radiographs and computed tomography scans. A paradoxical inlet view of the upper sacral segments on the injury anteroposterior pelvis was seen in twelve of thirteen patients (92.3 percent), and the diagnosis was confirmed with the lateral sacral view in all thirteen (100 percent) patients. Preoperatively, sacral kyphosis averaged 29 degrees, whereas postoperative sacral kyphosis averaged 28 degrees. Screw disengagement occurred without a change in position of the sacral fracture in the only patient treated with a single unilateral screw. All fractures healed clinically and radiographically. Of the nine patients with preoperative neurologic abnormalities, two (22 percent) patients had residual neurologic deficits. Both patients had associated multiple level lumbar burst fractures, which required decompression and instrumented stabilization. CONCLUSIONS: These sacral fractures are rare and occur after significant spinal axial loading. A paradoxic inlet view of the upper sacrum on the anteroposterior plain pelvic radiograph heralds the diagnosis. Delayed diagnosis is avoided by a high clinical suspicion, early lateral sacral radiographs, and pelvic computed tomography scans. Surgical stabilization may assist in early mobilization of the patient from recumbency and prevents progressive deformity with associated nerve root injury. Percutaneous fixation diminishes potential blood loss and operative times, yet still allows subsequent sacral decompression of the local neural elements using open techniques when necessary. Early percutaneous iliosacral screw fixation is effective treatment for these injuries.     

Sacroiliac fixation: a new technique after pelvic trauma

We propose a new technique for sacroiliac fixation for the treatment of pelvic fracture with vertical and horizontal instability (Tile class C). This fixation technique allows control of vertical displacement while allowing, if needed, a certain degree of movement in the horizontal plane to facilitate reduction of anterior lesions. The technique involves insertion of two sacral screws, one in S1 and one in S2, and two iliac screws. The iliac screws are inserted in the posterior iliac crest through two sacroiliac connectors placed on a rod linking the two sacral screws. Vertical displacement is controlled by blocking the screw heads on the connecting rod. If needed, a certain degree of horizontal mobility of the half pelvis can be allowed by loosening the connectors on the rods. This technique was used for 4 patients. Anatomic reduction was achieved and no secondary movement of the osteosynthesis material nor secondary displacement were observed. The quality of the fixation allowed rapid weight bearing in the standing position and early walking without crutches. This type of fixation can only be used for type C12 fractures in the Tile classification.     

改良钉棒系统治疗垂直不稳定骨盆骨折的生物力学研究

目的 探讨改良钉棒系统治疗垂直不稳定型骨盆骨折,并分析其生物力学性质.方法 在8例尸体骨盆标本上造模成垂直不稳定型骨盆骨折,分别行TOS术式固定、骶髂螺钉固定、改良钉棒系统固定,检测1000 N载荷下骨盆刚度、骨折分离移位距离及局部应变改变.结果 骨盆标本骨折模型采用各种不同固定方式,经生物力学测试,改良钉棒系统在载荷1000 N下刚度(224.3±18.3)N/mm及骨折分离移位距离(1.98±0.24)mm,明显优于骶髂螺钉固定(169.10±17.60)、(8.08±0.71)mm,差异有统计学意义(P＜0.01),与TOS(233.20±12.90)、(1.62±0.31)mm比较,差异无统计学意义(P＞0.05).结论 改良钉棒系统是一种生物力学性能较好的治疗垂直不稳定型骨盆骨折的新方法.     

Percutaneous screw fixation of fractures of the iliac wing and fracture-dislocations of the sacro-iliac joint (OTA Types 61-B2.2 and 61-B2.3, or Young-Burgess "lateral compression type II" pelvic fractures)

A technique for closed reduction and percutaneous screw fixation of fractures of the iliac wing and fracture-dislocations of the sacro-iliac joint is presented. Twenty-seven pelvic fractures were treated with attempted closed reduction followed by percutaneous screw fixation. Closed reduction failed in two patients. In the other twenty-five, closed reduction to within one centimeter of residual displacement was obtained, and was followed by stabilization with percutaneously placed cannulated screws. Complications included dislodgment of a screw from the superior pubic ramus in one patient, and partial cut-out of a screw along the inner cortex of the iliac wing in another. Two patients were lost to follow-up before fracture union occurred. The remaining twenty-three patients were followed-up for an average of twenty-seven months (range, 18-48 months). All of the fractures healed in the twenty-three patients who were not lost to follow-up. All but two of the patients who were working before injury returned to work. All but one of the patients was satisfied with the outcome of their pelvic fracture treatment. Closed reduction and percutaneous screw fixation of fractures of the posterior portion of the iliac wing yields acceptable reductions, with minimal blood loss and limited damage to the surrounding soft tissues.     

骨盆损伤中移位骶骨骨折的手术治疗

目的 探讨不稳定型骨盆损伤中移位骶骨骨折的手术方法及治疗效果.方法 对2000年9月至2007年9月收治的33例伴有骶骨骨折的骨盆损伤患者行手术治疗.根据AO/OTA的分型方法,骨盆B型损伤5例,C型28例.根据Denis的分型方法,骶骨I型骨折13例、Ⅱ型11例、Ⅲ型9例.其中早期合并原发性神经损伤23例.骶骨骨折应用张力带钢板固定1例;脊柱椎弓根钉棒系统经骨盆后方沿双侧髂嵴横向固定10例,经L_(4,5)或L_5S_1及双侧髂嵴后方纵向固定16例;骶髂螺钉固定3例;骶骨棒固定2例;骶髂螺钉联合骶骨棒固定1例.术中间期行椎板切除、马尾神经减压11例,二期行神经松解、骶前孔扩大术2例.结果 术后随访12～82个月,平均27.3个月.根据Majeed疗效标准,优17例、良7例、可2例、差7例.骶骨I型骨折疗效优良率为92.3%、Ⅱ型为72.7%、Ⅲ型为44.4%.神经损伤恢复情况在手术治疗组中优6例、良4例、无变化3例;在非手术治疗组中优6例、良1例、无变化3例.术后并发症包括腰骶部切口深部感染2例,腰骶僵硬不适2例.神经损伤一过性加重4例,迟发性骶神经损伤3例.结论 手术治疗是改善骶骨骨折复位质量的重要途径,骨盆前、后环损伤的联合制动是提高骨折内同定强度的有效方法.对手术指征明确的骶神经损伤,早期定位减压有助于其功能恢复.     

垂直不稳定骨盆骨折的手术治疗

目的：探讨切开复位内固定治疗垂直不骨盆骨折的疗效。方法：作者２年来采用切开复位内固定治疗垂直不稳定骨盆骨折１５例。固定方法有：前环骨折采用钢板固定;后环骨折分离采用骶骨棒,四孔方形钢板,松质骨螺钉固定。结果：随访时已有１２例下地行走,无腰腿痛,患肢缩短等并发症。结论：垂直不稳定骨盆骨折手术治疗的疗效满意。     

Trans-iliosacral plating for vertically unstable fractures of sacral spine associated with spinopelvic dissociation: A cadaveric study

Background:

The treatment algorithm for sacral fracture associated with vertical shear pelvic fracture has not emerged. Our aim was to study a new approach of fixation for comminuted and vertically unstable fracture pattern with spinopelvic dissociation to overcome inconsistent outcome and avoid complications associated with fixations. We propose fixation with well-contoured thick reconstruction plate spreading across sacrum from one iliac bone to another with fixation points in iliac wing, sacral ala and sacral pedicle on either side. Present biomechanical study tests the four fixation pattern to compare their stiffness to vertical compressive forces.

Materials and Methods:

Dissection was performed on human cadavers through posterior midline paraspinal approach elevating erector spinae from insertion with two flaps. Feasibility of surgical exposure and placement of contoured plate for fixation was evaluated. Ten age and sex matched computed tomography scans of pelvis with both hips were obtained. Reconstructions were performed with advantage windows 4.2 (GE Light Speed QX/I, General Electric, Milwaukee, WI, USA). Using the annotation tools, direct digital CT measurement (0.6 mm increments) of three linear parameters was carried out. Readings were recorded at S2 sacral level. Pelvic CT scans were extensively studied for entry point, trajectory and estimated length for screw placement in S2 pedicle, sacral ala and iliac wing. Readings were recorded for desired angulation of screw in iliac wing ala of sacrum and sacral pedicle with respect to midline. The readings were analyzed by the values of mean and standard deviation. Biomechanical efficacy of fixation methods was studied separately on synthetic bone. Four fixation patterns given below were tested to compare their stiffness to vertical compressive forces: 1) Single S1 iliosacral screw (7.5 mm cancellous screw), 2) Two S1 and S2 iliosacral screws, 3) Isolated trans-iliosacral plate, 4) Trans-iliosacral plate + single S1 iliosacral screw.

Statistical Analysis:

Mean of desired angulation for inserting screws and percentage of displacement on biomechanical testing was evaluated.

Results:

Mean angulations for inserting sacral pedicel were 12.3° (SD 2.7°) convergent to midline and divergent of 14° (SD 2.3°) for sacral ala screw and 23° (SD 4.9°) for iliac wing screw. All screws needed to be inserted at an angle of 90° to sacral dorsum to avoid violation of root canals. Cross headed displacement across fracture site was measured and plotted against the applied vertical shear load of 300 N in five cycles each for all the four configurations. Also, the force required for cross headed displacement of 2.5 mm and 5 mm was recorded for all configurations. Transmitted load across both ischial tuberosities was measured to resolve unequal distribution of forces. Taking one screw construct (configuration 1) as standard base reference, trans-iliosacral plate construct (configuration 3) showed equal rigidity to standard reference. Two screw construct (configuration 2) was 12% stronger and trans-iliosacral plate (configuration 4) with screw was 9% stronger at 2.5 mm displacing on 300 N force, while it showed 30% and 6%, respectively, at 5 mm cross-headed displacement.

Conclusions:

Trans-iliosacral plating is feasible anatomically, biomechanically and radiologically for sacral fractures associated with vertical shear pelvic fractures. Low profile of plate reduces the risk of hardware prominence and decreases the need for implant removal. Also, the fixation pattern of plate allows to spare mobile lumbosacral junction which is an important segment for spinal mobility. Biomechanical studies revealed that rigidity offered by plate for cross headed displacement across fracture site is equal to sacroiliac screws and further rigidity of construct can be increased with addition of one more screw. There is need for precountered thicker plate in future.