We present a case of lumbosacral fracture-dislocation, which was spontaneously reduced during radiological examination. Such rapid reduction is, however, not reliable for long-term stability. We would like to report this case briefly because spontaneous reduction of lumbosacral fracture-dislocation has not been reported previously.
Adult ; Dislocations/*physiopathology/surgery ; Humans ; Lumbar Vertebrae/*injuries ; Male ; Sacrum/*injuries ; Spinal Fractures/*physiopathology/surgery

OBJECTIVETo introduce a technique pertaining to S2 iliosacral screw insertion.

METHODSThe screw pathway was first measured on the preoperative pelvic CT scan or the standard sacral lateral radiograph to make sure the existence of the "safe zone" in the S2 segment for screw insertion. Under general anesthesia, patients were positioned supine or prone, depending on the injury pattern of pelvic ring or associated injuries requiring concomitant operation. The operation field was routinely sterilized using iodine and subsequent alcohol solution and draped. The tip of a guide wire was inserted through a stab wound to the posterior outer iliac table, manipulated in the "safe zone" being enclosed by the anterior aspect of the S2 nerve root tunnel, the anterior aspect of the sacral vertebrae, and the inferior aspect of the S1 foramen under the guidance of the standard sacral lateral fluoroscopy, and then the tip was hammered one to two millimeters into the iliac cortex. The guide wire progressed along the trajectory between the inferior aspect of the S1 foramen and the superior aspect of the S2 foramen on the pelvic outlet fluoroscopic view, and then along the posterior to the anterior aspect of the S2 sacral vertebrae and alae on the pelvic inlet fluoroscopic view with a predetermined length. At that moment, in order to ensure the safety, another standard sacral lateral view was imaged to detect the guide wire's tip which should locate posterior to the anterior aspect of the sacral vertebrae and anterior to the anterior aspect of the S2 nerve root tunnel. Subsequently, the depth was measured, the trajectory was drilled and tapped, and the screw was inserted. Following the removal of the guide wire, the wound was irrigated and sutured.

RESULTSUtilizing this insertion technique, there were 30 S2 iliosacral screws in total being placed to stabilize the injured and unstable posterior pelvic ring in 27 patients. Each S2 screw was accompanied by an ipsilateral S1 screw. The S2 screw location was completely intraosseous in all patients, which was verified by postoperative pelvic outlet and inlet radiographs and CT scans. The insertion accuracy was 100 percent in the present series.

CONCLUSIONThe S2 iliosacral screw insertion technique is safe and reproducible to guide the placement of the S2 screw, enhancing the stability for the compromised posterior pelvic ring.

Adult ; Bone Screws ; Female ; Fractures, Bone ; surgery ; Humans ; Ilium ; injuries ; surgery ; Male ; Sacrum ; injuries ; surgery

Charcot spinal arthropathy is a rare, progressive type of vertebral joint degeneration that occurs in the setting of any preexisting condition characterized by decreased afferent innervation to the extent that normal protective joint sensation in the vertebral column is impaired. The authors report on a case of Charcot arthropathy of the lower lumbar spine mimicking a spinal tumor following cervical cord injury.
Joints ; Preexisting Condition Coverage ; Sacrum ; Sensation ; Spinal Cord Injuries* ; Spinal Cord* ; Spine*

The occult sacral fracture has no symptoms of sacral nerves injuries and no severe pain. These occult sacral fractures have no significant fracture signs on plain X-ray film, which can be found only by spiral CT or MRI and be misdiagnosed easily. This article made a brief review on the diagnosis and treatment of this type of sacral fractures.
Humans ; Magnetic Resonance Imaging ; Sacrum ; injuries ; Spinal Fractures ; diagnosis ; etiology ; surgery ; Tomography, Spiral Computed

OBJECTIVETo observe the morphological characteristics of sacral fracture under different impact loads.

METHODTen fresh pelvic specimens were loaded in dynamic or static state. A series of mechanical parameters including the pressure strain and velocity were recorded. Morphological characteristics were observed under scanning electron microscope.

RESULTSThe form of sacral fracture was related to the impact energy. Under low energy impact loads, ilium fracture, acetabulum fracture and crista iliaca fracture were found. Under high energy impact loads, three types of sacral fracture occurred according to the classification of Denis: sacral ala fracture, Type I fracture; sacral foramen cataclasm fracture, Type II fracture; central vertebral canal fracture, Type III fracture. Nerve injury of one or two sides was involved in all three types of sacral fracture. The fracture mechanism of sacrum between the dynamic impact and static compression was significantly different. When the impact energy was above 25 J, sacral foramen cataclasm fracture occurred, involving nerve root injury. When it was below 20 J, ilium and sacral fracture was most likely to occur. When it was 20 approximately 25 J, Type I fracture would occur. While in the static test, most of the fracture belonged to ilium or acetabulum fracture. The cross section of sacrum was crackly and the bone board of Haversian system was brittle, which could lead to separation of bone boards and malposition of a few of cross bone boards.

CONCLUSIONSIn dynamic state, sacrum fracture mostly belongs to Type I and Type II, and usually involves the nerve roots. Sacrum fracture is relevant to the microstructures, the distribution of the bone trabecula, the osseous lacuna and the Haversian system of sacrum. The fracture of ilium and acetabulum more frequently appears in static state, with slight wound of peripheral tissues.

Biomechanical Phenomena ; Humans ; Male ; Microscopy, Electron, Scanning ; Sacrum ; injuries ; pathology ; Spinal Fractures ; pathology ; physiopathology ; surgery ; Spinal Nerve Roots ; injuries

OBJECTIVETo investigate the anorectal status in patients with lumbosacral spinal cord injury (SCI).

METHODSTwenty six patients (23 males, 3 females) with lumbosacral SCI and 13 normal volunteers were enrolled into this study as controls. The median age was 43.7 years (ranging 17-68 years) and the median time of patients since injury was 59.1 months (ranging 8 months-15 years). They were diagnosed as complete lumbosacral SCI (n =2, American Spinal Injury Association (ASIA) score A), or incomplete lumbosacral SCI (n=24, ASIA score B-D) with mixed symptoms of constipation and/or fecal incontinence, and were studied by anorectal manometry. None of the patients had any medical treatments for neurogenic bowel prior to this study.

RESULTSThe maximum anal resting pressure in lumbosacral SCI patients group was slightly lower than that in control group (One-way ANOVA: P=0.939). During defecatory maneuvers, 23 of 26 (88.5%) patients with lumbosacral SCI and 1 of 13 (7.7%) in the control group showed pelvic floor dysfunction (PFD) (Fisher's exact test: P<0.0001). Rectoanal inhibitory reflex (RAIR) was identified in both patients with lumbosacral SCI and the controls. The rectal volume for sustained relaxation of the anal sphincter tone in lumbosacral SCI patients group was significantly higher than that in the control group (Independent-Samples t test: P<0.0001). The mean rectal volume to generate the first sensation was 92.7 ml+/-57.1 ml in SCI patients, 41.5 ml+/-13.4 ml in the control group (Independent-Samples t test: P<0.0001).

CONCLUSIONSMost of the patients with lumbosacral SCI show PFD during defecatory maneuvers and their rectal sensation functions are severely damaged. Some patients exhibit abnormal cough reflex. Anorectal manometry may be helpful to find the unidentified supraconal lesions. RAIR may be modulated by central nervous system (CNS).

Adolescent ; Anal Canal ; physiopathology ; Constipation ; etiology ; physiopathology ; Fecal Incontinence ; etiology ; physiopathology ; Female ; Humans ; Lumbar Vertebrae ; injuries ; Male ; Rectum ; physiopathology ; Sacrum ; injuries ; Sensation ; Spinal Cord Injuries ; complications ; physiopathology

OBJECTIVETo observe the therapeutic effects of iliac nail in the treatment of lumbar sacral and pelvis reconstruction.

METHODSForm January 2004 to February 2010,10 patients (4 males and 6 females, ranging age from 25 to 75 years, with an average of 46.5 years ) were treated. Among the patients, 5 cases were L5S1 vertebral tuberculosis, 2 cases were sacral giant-cell tumors and 3 cases were severe osteoporosis combined with lumbar sacral slipping. The main symptoms manifested low back pain, limited activity and dysphasia before treatment. Iliac nail and lumbar-sacral pedicle screw were used for reconstruction of lumbar-sacral spine and pelvis. Nakai scale was used to evaluate therapeutic effects, Suk scale for osseous fusion.

RESULTSAll operations were succeful, obtained primary healing. All the patients were followed up, and the mean time of follow-up was 24 months (ranged from 18 to 36 months). The complications, such as weakness and decreased sensation of lower libs and activity, increased spinal cord injury, were not occurred after operation. According to Nakai scale, 7 cases got excellent result, 2 good and 1 fair. All bone graft were bony fusion with an average time of 3.5 months.

CONCLUSIONIliac nail can fixed well between lumbar vertebra and pelvis and solve the problem of fixation due to pathological changes of lumbosacral region. It is an ideal method of less blood loss and operating time.

Adult ; Aged ; Bone Nails ; Female ; Fracture Fixation, Internal ; instrumentation ; Humans ; Internal Fixators ; Lumbar Vertebrae ; injuries ; surgery ; Male ; Middle Aged ; Pelvis ; injuries ; surgery ; Sacrum ; injuries ; surgery

OBJECTIVETo provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique.

METHODSPelvis image data were obtained from three-dimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The three-dimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the three-dimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction (total reduction, half reduction and non-reduction) were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws.

RESULTSAccurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate.

CONCLUSIONThe navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.

Bone Screws ; Female ; Fracture Fixation ; methods ; Humans ; Imaging, Three-Dimensional ; Male ; Reconstructive Surgical Procedures ; methods ; Sacrum ; injuries ; surgery

OBJECTIVETo compare the stability of sacroiliac screws fixation for the treatment of bilateral vertical sacral fractures to provide reference for clinic application.

METHODSA finite element model of Tile C pelvic ring injury (bilateral type Denis II fracture of sacrum) was produced. The bilateral sacral fractures were fixed with sacroiliac screws in 4 types of models respectively: two bidirectional sacroiliac screws fixation in the S₁ segment, two bidirectional sacroiliac screws fixation in the S₂ segment, one sacroiliac screw fixation in the S₁ segment and one sacroiliac screw fixation in the S₂ segment, two bidirectional sacroiliac screws fixation in S₁ and S₂ segments respectively. By the ABAQUS 6.9.1 software, in the case of standing on both feet, 600 N vertical load was imitated to be imposed to the superior surface of the sacrum and downward translation and backward angle displacement of the middle part of the sacral superior surface and everted angle displacement of the top of iliac bones were extracted for analysis. The stability of sacroiliac screws fixation was compared according to the principle of the better stability the smaller displacement.

RESULTSThe stability of 2 bidirectional sacroiliac screws fixation in S₁ and S₂ segments respectively was markedly superior to that of 2 bidirectional sacroiliac screws fixation in S₁ or S₂ segment and was also markedly superior to that of one sacroiliac screw fixation in S₁ segment and one sacroiliac screw fixation in S₂ segment. The vertical and everted stability (the downward translation: 0.531 mm; the everted angle displacement: 0.156° (left side), 0.163° (right side)) of sacroiliac screws fixation in two bidirectional sacroiliac screws fixation in the S₂ segment was superior to that of two bidirectional sacroiliac screws fixation in the S₁ segment (the downward translation: 0.673 mm; the everted angle displacement: 0.200° (left side), 0.232° (right side)). The rotational stability of two bidirectional sacroiliac screws fixation in the S₁ segment (the backward angle displacement: 0.269°) was superior to that of two bidirectional sacroiliac screws fixation in the S₂ segment (the backward angle displacement: 0.287°). Moreover, the rotational stability of one sacroiliac screw fixation in the S₁ segment and one sacroiliac screw fixation in the S₂ segment was inferior to that of two bidirectional sacroiliac screws fixation in the S₁ segment or two bidirectional sacroiliac screws fixation in the S₂ segment, and the vertical and everted stability of one sacroiliac screw fixation in the S₁ segment and one sacroiliac screw fixation in the S₂ segment was between that of two bidirectional sacroiliac screws fixation in the S₁ segment and two bidirectional sacroiliac screws fixation in the S₂ segment.

CONCLUSIONSTwo bidirectional sacroiliac screws fixation in S₁ and S₂ segments respectively is recommended to be utilized for fixing bilateral sacral fractures of Tile C pelvic ring injury as far as possible. It is suggested to choose sacral segments in which sacroiliac screws fixed according to vertical, rotational and everted stability degree of sacral fractures.

Adult ; Bone Screws ; Computer Simulation ; Female ; Finite Element Analysis ; Fracture Fixation, Internal ; methods ; Fractures, Bone ; surgery ; Humans ; Sacrum ; injuries ; surgery

Finite element method (FEM) was used to investigate the biomechanical properties of three types of surgical fixations of U-shaped sacral fractures. Based on a previously established and validated complete lumbar-pelvic model, three models of surgical fixations of U-shaped sacral fractures were established: ① S1S2 passed through screw (S1S2), ② L4-L5 pedicle screw + screw for wing of ilium (L4L5 + IS), and ③ L4-L5 pedicle screw + S1 passed through screw + screw for wing of ilium (L4L5 + S1 + IS). A 400 N force acting vertically downward, along with torque of 7.5 N·m in different directions (anterior flexion, posterior extension, axial rotation, and axial lateral bending), was exerted on the upper surface of L4. Comparisons were made on differences in separation of the fracture gap and maximum stress in sitting and standing positions among three fixation methods. This study showed that: for values of separation of the fracture gap produced by different operation groups in different positions, L4L5 + S1 + IS was far less than L4L5 + IS and S1S2. For internal fixators, the maximum stress value produced was: L4L5 + IS > L4L5 + S1 + IS > S1S2. For the intervertebral disc, the maximum stress value produced by S1S2 is much larger than that of L4L5 + S1 + IS and L4L5 + IS. In a comprehensive consideration, L4L5 + S1 + IS could be prioritized for fixation of U-shaped sacral fractures. The objective of this research is to compare the biomechanical differences of three different internal fixation methods for U-shaped sacral fractures, for the reference of clinical operation.
Biomechanical Phenomena ; Finite Element Analysis ; Fracture Fixation ; methods ; Humans ; Lumbar Vertebrae ; Pedicle Screws ; Sacrum ; injuries ; Spinal Fractures ; surgery ; Spinal Fusion