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

Local flaps exhibit excellent color matching that no other type of flap can compete with. Moreover, surgery using a local flap is easier and faster than surgery using a distant or free flap. However, local flaps can be much more difficult to design. We designed 2 templates to plan a V-Y rotation advancement flap. The template for a unilateral V-Y rotation advancement flap was used on the face (n=5), anterior tibia (n=1), posterior axilla (n=1), ischium (n=1), and trochanter (n=2). The template for a bilateral flap was used on the sacrum (n=8), arm (n=1), and anterior tibia (n=1). The causes of the defects were meningocele (n=3), a decubitus ulcer (n=5), pilonidal sinus (n=3), and skin tumor excision (n=10). The meningocele patients were younger than 8 days. The mean age of the adult patients was 50.4 years (range, 19–80 years). All the donor areas of the flaps were closed primarily. None of the patients experienced wound dehiscence or partial/total flap necrosis. The templates guided surgeons regarding the length and the placement of the incision for a V-Y rotation advancement flap according to the size of the wound. In addition, they could be used for the training of residents.
Adult ; Arm ; Axilla ; Femur ; Free Tissue Flaps ; Humans ; Ischium ; Meningocele ; Necrosis ; Pilonidal Sinus ; Pressure Ulcer ; Reconstructive Surgical Procedures ; Sacrum ; Skin ; Skin Neoplasms ; Surgeons ; Surgical Flaps ; Tibia ; Tissue Donors ; Wounds and Injuries

A 35-year-old woman visited the emergency department for a pedestrian traffic accident. Severe tenderness was noted at the posterior sacrum area, without open wound or initial neurologic deficit. Fracture of the left sacral ala extended to the S1 foramen, anterior acetabulum, and pubic ramus. Two weeks after the injury, she presented aggravating radiculopathy with the weakness of the left great toe plantar flexion. The S1 nerve root was compressed by the fracture fragments in the left S1 foramen. Decompressive S1 foraminotomy was performed. The postoperative follow-up computed tomography scan showed successful decompression of the encroachment, and the patient recovered well from the radiculopathy with motor weakness. She was able to resume her daily routine activity. We suggest that early decompressive sacral foraminotomy could be a useful additional procedure in selective sacral zone II fractures that are accompanied by radiculopathy with a motor deficit.
Accidents, Traffic ; Acetabulum ; Adult ; Decompression ; Emergency Service, Hospital ; Female ; Follow-Up Studies ; Foraminotomy* ; Humans ; Neurologic Manifestations ; Radiculopathy ; Sacrum ; Toes ; Wounds and Injuries

A 35-year-old woman visited the emergency department for a pedestrian traffic accident. Severe tenderness was noted at the posterior sacrum area, without open wound or initial neurologic deficit. Fracture of the left sacral ala extended to the S1 foramen, anterior acetabulum, and pubic ramus. Two weeks after the injury, she presented aggravating radiculopathy with the weakness of the left great toe plantar flexion. The S1 nerve root was compressed by the fracture fragments in the left S1 foramen. Decompressive S1 foraminotomy was performed. The postoperative follow-up computed tomography scan showed successful decompression of the encroachment, and the patient recovered well from the radiculopathy with motor weakness. She was able to resume her daily routine activity. We suggest that early decompressive sacral foraminotomy could be a useful additional procedure in selective sacral zone II fractures that are accompanied by radiculopathy with a motor deficit.
Accidents, Traffic ; Acetabulum ; Adult ; Decompression ; Emergency Service, Hospital ; Female ; Follow-Up Studies ; Foraminotomy* ; Humans ; Neurologic Manifestations ; Radiculopathy ; Sacrum ; Toes ; Wounds and Injuries

OBJECTIVETo evaluate the clinical effects of iliolumbar fixation for the sacrum fractures of Denis type II.

METHODSThe clinical data of 86 patients with sacrum fracture of Denis type II treated by iliolumbar fixation from January 2008 to January 2012 were retrospectively analyzed. There were 55 males and 31 females, aged from 17 to 55 years old with an average of 39.1 years. Among them, 73 cases complicated with pelvis fracture and 13 cases with acetabular fracture; 37 cases with sacral neurological symptoms and 49 cases without sacral neurological symptoms. Fracture healing time, nerve function, clinical function and complications were observed in the patients.

RESULTSIn 86 cases, 6 cases were out of followed-up and 80 cases were followed up from 24 to 71 months with an average of 36 months. The mean fracture healing time was 13 weeks (ranged, 10 to 38 weeks). According to Gibbons scoring to evaluate the neurological function, preoperative nerve rehabilitation, lower limbs feeling, lower limbs activity,bladder and rectum function,total score respectively were 0.62 +/- 0.04, 1.54 +/- 0.35, 1.12 +/- 0.18, 0.23 +/- 0.01, 3.46 +/- 0.47 and postoperative respectively were 0.82 +/- 0.12, 0.36 +/- 0.04, 0.05 +/- 0.01, 0.03 +/- 0.01, 1.25 +/- 0.22, there were statistically significant differences between preoperative and postoperative (P < 0.05). According to Majeed scoring to evaluate the clinical function, postoperative pain, standing, sitting, sexual life, work ability, total score respectively were 22.54 +/- 4.02, 27.93 +/- 5.46, 8.47 +/- 3.61, 2.54 +/- 1.33, 16.46 +/- 4.34, 81.32 +/- 8.73, 60 cases got excellent results, 17 good, 3 fair. The main complications including fracture nonunion of 5 cases,deep incision infection of 1 case, and screw prominence resulting uncomfortable of 8 cases.

CONCLUSIONIliolumbar fixation has the advantages of stable fixation, satisfactory functional rehabilitation, less complications, and is a good method in treating sacrum fracture of Denis type II.

Adolescent ; Adult ; Bone Screws ; Female ; Fracture Fixation, Internal ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Sacrum ; injuries ; surgery ; Spinal Fractures ; surgery ; Treatment Outcome ; Young Adult

OBJECTIVETo evaluate the erectile and ejaculatory function of sacral tumor patients after sacral nerve root resection and investigate the relationship of erectile and ejaculatory dysfunction (EED) with the level of sacral nerve injury.

METHODSThis retrospective study included 47 male patients aged 16 to 63 (32.6 +/- 6.8) years treated by sacral tumor resection between January 2008 and August 2013. According to the levels of the sacral nerve roots spared in surgery, the patients were divided into four groups: bilateral S1-S3 (n=16), unilateral S1-S3 (n=21), unilateral S1-S2 (n=6), and unilateral S1 (n=4). The patients were followed up for 12 to 41 (27.2 +/- 10.9) months by questionnaire investigation, clinic review, and telephone calls about their erectile and ejaculatory function at 3, 6 and 12 months after surgery and in August 2013.

RESULTSIn the bilateral S1-S3 group, the incidence rates of EED were 31.25% (5/16), 25% (4/16), and 12.5% (2/16) at 3, 6, and 12 months respectively after surgery, with recovery of erectile and ejaculatory function in August 2013. The incidence rates of EED in the unilateral S1-S3 group were 85.71% (18/21), 71.43% (15/21), 52.38% (11/21), and 42.86% (9/21) at 3, 6 and 12 months and in August 2013, respectively; those in the unilateral S1-S2 group were 100% (6/6), 83.33% (5/6), 83.33% (5/6), and 66.67% (4/6) at the four time points; and those in the unilateral S1 group were all 100% (4/4). No statistically significant differences were found in the incidence rate of EED among the patients of different ages or tumor types (P > 0.05).

CONCLUSIONThe incidence of postoperative EED in male patients treated by sacral tumor resection is closely related to the mode of operation. Sparing the S3 nerve root at least unilaterally in sacral tumor resection is essential for protecting the erectile and ejaculatory function of the patient.

Adolescent ; Adult ; Ejaculation ; physiology ; Erectile Dysfunction ; epidemiology ; etiology ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Organ Sparing Treatments ; Peripheral Nervous System Neoplasms ; surgery ; Postoperative Complications ; epidemiology ; Postoperative Period ; Retrospective Studies ; Sacrum ; Spinal Nerve Roots ; injuries ; surgery ; Surveys and Questionnaires ; Young Adult

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

OBJECTIVETo investigate the effect of electrical stimulation to sacral spinal nerve 3 (S₃ stimulation) on gastrointestinal dysfunction after spinal cord injury (SCI).

METHODSSix rabbits were taken as normal controls to record their gastrointestinal multipoint biological discharge, colon pressure and rectoanal inhibitory reflex. Electrodes were implanted into S₃ in another 18 rabbits. Then the model of SCI was conducted following Fehling's method: the rabbit S₃ was clamped to induce transverse injury, which was claimed by both somatosensory evoked potential and motion evoked potential. Two hours after SCI, S₃ stimulation was conducted. The 18 rabbits were subdivided into 3 groups to respectively record their gastrointestinal electric activities (n=6), colon pressure (n=6), and rectum pressure (n=6). Firstly the wave frequency was fixed at 15 Hz and pulse width at 400 μs and three stimulus intensities (6 V, 8 V, 10 V) were tested. Then the voltage was fixed at 6 V and the pulse width changed from 200 μs, 400 μs to 600 μs. The response was recorded and analyzed. The condition of defecation was also investigated.

RESULTSAfter SCI, the mainly demonstrated change was dyskinesia of the single haustrum and distal colon. The rectoanal inhibitory reflex almost disappeared. S₃ stimulation partly recovered the intestinal movement after denervation, promoting defecation. The proper stimulus parameters were 15 Hz, 400 μs, 6 V, 10 s with 20 s intervals and 10 min with 10 min intervals, total 2 h.

CONCLUSIONS₃ stimulation is able to restore the intestinal movement after denervation (especially single haustrum and distal colon), which promotes defecation.

Animals ; Disease Models, Animal ; Electric Stimulation ; Electrodes, Implanted ; Evoked Potentials, Motor ; physiology ; Evoked Potentials, Somatosensory ; physiology ; Gastrointestinal Tract ; physiopathology ; Rabbits ; Sacrum ; innervation ; Spinal Cord Injuries ; physiopathology

OBJECTIVETo introduce the location and course of S1, S2 sacral nerve root tunnel and to clarify the significance of the anterior aspect of sacral nerve root tunnel on placement of iliosacral screw on the standard lateral sacral view.

METHODSFirstly the data of 2.0 mm slice pelvic axial CT images were imported into Mimics 10.0, and the sacrum, innominate bones, and sacral nerve root tunnels were reconstructed into 3D views respectively, which were rotated to the standard lateral sacral views, pelvic outlet and inlet views. Then the location and course of the S1, S2 sacral nerve root tunnel on each view were observed.

RESULTSThe sacral nerve root tunnel started from the cranial end and anterior aspect of the vertebral canal of the same segment and ended up to the anterior sacral foramen with a direction from cranial-posterior-medial to caudal-anterior-lateral. The tunnel had a lower density than the iliac cortex and greater sciatic notch on the pelvic X-rays,especially on the standard sacral lateral view, on which it showed up as a disrupted are line and required more careful recognition.

CONCLUSIONIt can prevent the iliosacral screw from penetrating the sacral nerve root tunnel and vertebral canal when recognizing the anterior aspect of sacral nerve root tunnel and choosing it as the caudal-posterior boundary of the "safe zone" on the standard lateral sacral view.

Adult ; Aged ; Bone Screws ; Female ; Fracture Fixation, Internal ; Fractures, Bone ; surgery ; Humans ; Male ; Middle Aged ; Pelvic Bones ; diagnostic imaging ; injuries ; innervation ; surgery ; Radiography ; Sacrococcygeal Region ; diagnostic imaging ; innervation ; surgery ; Sacrum ; diagnostic imaging ; injuries ; innervation ; surgery ; Spinal Nerve Roots ; diagnostic imaging ; surgery ; Young Adult

PURPOSE: A sacral chordoma is a rare, slow-growing, primary bone tumor, arising from embryonic notochordal remnants. Radical surgery is the only hope for cure. The aim of our present study is to analyse our experience with the challenging treatment of this rare tumor, to review current treatment modalities and to assess the outcome based on R status. METHODS: Eight patients were treated in our institution between 2001 and 2011. All patients were discussed by a multidisciplinary tumor board, and an en bloc surgical resection by posterior perineal access only or by combined anterior/posterior accesses was planned based on tumor extension. RESULTS: Seven patients underwent radical surgery, and one was treated by using local cryotherapy alone due to low performance status. Three misdiagnosed patients had primary surgery at another hospital with R1 margins. Reresection margins in our institution were R1 in two and R0 in one, and all three recurred. Four patients were primarily operated on at our institution and had en bloc surgery with R0 resection margins. One had local recurrence after 18 months. The overall morbidity rate was 86% (6/7 patients) and was mostly related to the perineal wound. Overall, 3 out of 7 resected patients were disease-free at a median follow-up of 2.9 years (range, 1.6-8.0 years). CONCLUSION: Our experience confirms the importance of early correct diagnosis and of an R0 resection for a sacral chordoma invading pelvic structures. It is a rare disease that requires a challenging multidisciplinary treatment, which should ideally be performed in a tertiary referral center.
Chordoma* ; Cryotherapy ; Diagnosis ; Diagnostic Errors* ; Follow-Up Studies ; Hope ; Humans ; Notochord ; Perineum ; Rare Diseases ; Recurrence ; Sacrum ; Tertiary Care Centers ; Wounds and Injuries