Location of the sacral pedicle, foramina, and ala on the lateral aspect of the sacrum: a radiographic study

Twenty-one adult dry-bone sacral specimens were used to quantitatively determine the location of the sacral pedicle, foramina, and ala on the lateral radiographic view of the sacrum. The anterior and posterior sacral foramina from S1 to S3, the midlines of the anterior sacrum and cephalad border of the S1 vertebral body, and the lateral limit of the lateral sacral mass were outlined with wires. A lateral radiograph was taken, and measurements were made directly from the radiograph. The average sacral pedicle height for both male and female specimens was approximately 20 mm for S1, 12 mm for S2, and 7 mm for S3. The sacral foramina height averaged approximately 13 mm for S1 and S2, and 10 mm for S3. The average ala and S1 body-ala angles were 88 degrees and 35 degrees. The distance from the ala tip to the anterior aspect of the sacrum averaged 12 mm, and the average anterior height of the S1 vertebral body above the ala was 11 mm. These measurements, in conjunction with inlet and outlet radiographs, may aid in the recognition of the vital structures of the sacrum on the lateral radiographic view and enhance the safety of dorsal sacral screw placement.     

Proximity of iliosacral screws to neurovascular structures after internal fixation

The placement of iliosacral screws for the stabilization of pelvic ring lesions is technically demanding. The postoperative computed tomography scans of 31 patients who had 57 iliosacral screws placed for various indications were studied to determine the proximity of these screws to neurovascular structures. The closest distance of the screws from the S1 foramen averaged 3 mm. (range, 0-10.5 mm); the average closest distance to the anterior cortex of the sacral ala was 4.8 mm (range, 0-15.3 mm). The corridor for the insertion of the screws between the S1 foramen and the anterior cortex of the sacrum averaged 21.7 mm (range, 16.2-28.9 mm). Trigonometric analysis of these dimensions suggests that deviations of the surgeon's hand by as little as 4 degrees may direct iliosacral screws either into the S1 foramina or through the anterior cortex of the sacrum.     

Anterior transpedicular fixation of the lower thoracic and lumbar spine. Experimental verification using a new direction finder

Currently, no anterior spinal implant provides a strong bone-screw interface because of the cancellous characteristics of the vertebral body. A more secure anchorage could be obtained by anterior transpedicular screw fixation. Four hundred transpedicular screws located between T7 and L5 were placed using the newly developed direction finder. Measurements were obtained directly from radiographs of the cadaveric specimens. In 10 cases (2.5%), the screws crossed the medial pedicle border, but never by more than 1.4 mm. A lateral protrusion was noted in another 41 screws (10%), with no protrusion greater than 2.2 mm. Encroachments beyond the superior or inferior border were not observed. The mean angle of the screws at each level measured between 7 and 19 in the transverse plane and between 2 and 4.5 in the sagittal plane. This technique should be reserved for vertebrae without significant arthritic changes. The rare screw with minimal infraction through the medial or lateral pedicle wall should not cause any vascular or neural compromise. The anterior transpedicular screw technique appeared relatively safe (88%) and encouraged the development of the new plate system for anterior spinal stabilization.     

Anatomic considerations of anterior transarticular screw fixation for atlantoaxial instability

STUDY DESIGN: Anatomic parameters of C1 and C2 were measured in 30 dried human cervical spines. Anterior transarticular C1-C2 screws were placed in 15 cadaveric spines. OBJECTIVE: To provide anatomic data for anterior transarticular atlantoaxial screw or C1-C2 screw and plate fixation. SUMMARY OF BACKGROUND DATA: A posterior approach to fixation in the atlantoaxial joint has been well described. Damage to the vertebral artery is documented as a rare complication of posterior atlantoaxial transarticular screw fixation. An anterior surgical approach to exposing the upper cervical spine for internal fixation and bone graft recently has been developed. No anatomic information regarding the anterior transarticular atlantoaxial screw or screw and plate fixation between C1 and C2 is available in the literature. METHODS: Direct measurements using digital calipers and a goniometer were taken from 30 pairs of dried human C1 and C2 vertebrae. The anterior transarticular C1-C2 screw insertion point is at the junction of the lateral edge of the C2 vertebral body to 4 mm above the inferior edge of the C2 anterior arch. The parameters related to anterior transarticular atlantoaxial screw fixation or screw and plate fixation between the C1 lateral mass and the C2 vertebral body were measured. Fifteen embalmed cadavers were used for anterior C1-C2 transarticular screw placement. Longer screws (30-40 mm) were used to detect whether the screw tips violated the upper cervical canal or vertebral arteries. RESULTS: In the anterior transarticular atlantoaxial screw placement, lateral angulation of the screw placement relative to sagittal plane ranged from 4.8 +/- 1.8 degrees to 25.3 +/- 2.6 degrees. The posterior angulation of the screw placement relative to the coronal plane ranged from 12.8 +/- 3.1 degrees to 22.6 +/- 3.2 degrees. The length of the medial screw path ranged from 14.7 +/- 1.5 mm to 25.4 +/- 2.8 mm. In the anterior screw and plate fixation, the anteroposterior diameter of the inferior facet articular surface ranged from 16.2 +/- 1.6 mm to 17.1 +/- 1.8 mm. The anteroposterior diameter of the C2 vertebral body ranged from 9.3 +/- 1 mm to 16.2 +/- 1.8 mm. The anterior prevascular retropharyngeal approach appropriately exposed the atlantoaxial joint for anterior transarticular C1-C2 screw placement. No screws violated the vertebral artery and cervical canal. CONCLUSIONS: An anterior transarticular atlantoaxial screw 15-25 mm long can be inserted with a lateral angulation of 5-25 degrees relative to the sagittal plane and a posterior angulation of 10-25 degrees relative to the coronal plane. Additionally, in C1-C2 anterior plate fixation screws 15 mm long could be anchored in the inferior facet of the C1, and screws 9-15 mm long could be anchored in the C2 vertebral body.     

Occult anterior sacral meningocele

Anterior sacral meningocele is a rare congenital malformation consisting of a spinal fluid-filled sac in the pelvis communicating by a small neck with the spinal subarachnoid space through a sacral defect. This entity should be considered if the characteristic scimitar sacrum is observed on a pelvic roentgenogram. If signs and symptoms also suggest a meningocele, special studies such as ultrasonography and myelography are indicated to establish the diagnosis of an anterior sacral meningocele. Computerized tomography provides additional evidence of spinal-abdominal extension of this lesion.     

Anterior sacral meningocele presenting as abdominal mass

Anterior sacral meningocele is a rare entity. It arises from a congenital defect of the sacrum and the coccyx through which herniation of the caudal portion of the meninges and their contents occurs, forming a cyst-like structure. The cystic mass, which lies between the rectum and sacrum, produces a variety of symptoms depending on its size and contents and constitutes a diagnostic problem. A case of anterior sacral meningocele is presented, including the physical signs, differential diagnosis, and the dangers of aspiration or surgical intervention.     

Retrospective diagnostics of congenital cytomegalovirus infection performed by polymerase chain reaction in blood stored on filter paper

OBJECTIVE: External reference points, particularly Kirschner pins (K-wire), placed in the region of the nasion have been shown to improve the accuracy of maxillary vertical repositioning. Although no complications associated with this technique have been reported, there is a potential for injury to the anterior cranial fossa or frontal sinus. The purpose of this study was to measure the shortest distance from the nasion to the anterior cranial fossa and from the nasion to the frontal sinus. These measurements were used to establish anatomic guidelines governing safe placement of external reference point pins. STUDY DESIGN: Twenty-seven cadaver heads were sectioned in the midsagittal plane for gross study. Using a Boley gauge, two specific measures were obtained: (1) distance from deepest depression of nasion to the most anterior and inferior projection of the anterior cranial fossa, and (2) distance from nasion to the most inferior aspect of the frontal sinus. All measurements were made in the midsagittal plane. RESULTS: The average distance from nasion to anterior cranial fossa was 16.9 mm (range 13.0 to 20.0 mm) and the smallest distance, 13.0 mm, was seen in two specimens. The average distance from nasion to the frontal sinus was 6.2 mm (range 2.0 to 10.0 mm) and the smallest distance, 2.0 mm, was seen in three specimens. CONCLUSION: Based on our findings, we recommend the following: (1) place pin to a depth of no more than 8 mm into bone, (2) place pin 5 to 10 mm inferior to soft tissue nasion, and (3) place pin in an anterosuperior to posteroinferior direction (i.e., roughly perpendicular to the nasal dorsum). When these anatomic guidelines are followed, one would expect minimal morbidity associated with the placement of ERP pins.     

Fatal cardiac tamponade associated with posterior spinal instrumentation. A case report

STUDY DESIGN: Case report of a fatal complication of pedicle screw instrumentation and review of the literature. OBJECTIVE: To describe the clinical and postmortem findings in a 35-year-old man who sustained a T11 burst fracture that was managed by transpedicular posterior instrumentation and who died 12 days after surgery of cardiac tamponade caused by a prick injury of the right coronary artery. SUMMARY OF BACKGROUND DATA: Posterior pedicle screw instrumentation is considered a safe and effective method for stabilizing a spinal motion segment. Nevertheless, there are several rare but significant complications that may occur. This is the first report of a heart tamponade after transpedicular screw insertion. METHODS: A 35-year-old man was treated for a T11 burst fracture with posterior transpedicular stabilization. The surgery was uncomplicated. RESULTS: Twelve days after the intervention, the patient died of cardiogenic shock. Postmortem examination showed a heart tamponade of 350 mL blood originating in a prick injury of the right coronary artery. Histologic findings showed evidence that the injury was caused during surgery by a Kirschner wire. CONCLUSION: There are numerous possible intraoperative complications in posterior pedicle screw fixation, such as nerve root and spinal cord injuries. This case of a fatal heart tamponade after transpedicular screw insertion is rare. It shows that the surgeon must be aware of potential risks associated with such a procedure and have a comprehensive three-dimensional understanding of the anatomic structures involved.     

Molecular advances in pancreatic cancer

The purpose of this study was to quantify in vivo the three-dimensional motion patterns of the sacroiliac joint during passive manipulations as the opinions about the extent of motion of this joint are varied. 12 sacroiliac joints of 6 patients with clinically and radiologically normal joints were investigated. All patients were treated with an external fixator for diagnostic purposes of low back pain unrelated of this study. The motion of the sacroiliac joint was measured continuously with a three-dimensional goniometric system, which was mounted at the end of Schanz screws implanted in S1 and the ilium. All measurements showed relatively small rotation angles around the three main axis to the body between the ilium and the sacrum (< 2 degrees) and very small translations between the screw entry points into the bones (< 1 mm). The maximum rotation angle in the sagittal plane was 1.3 degrees on the right joint and 1.6 degrees on the left joint for flexion plus extension. It is questionable whether this motion can be quantified during manual manipulation. Extension of the hip always produced the largest motion in the sacroiliac joint.     

Material Flow during Friction Stir Welding of HSLA 65 Steel

Material flow during friction stir welding of HSLA-65 steel was investigated by crystallographic texture analysis. During the welding process, the steel deforms primarily by local shear deformation in the austenite phase and then transforms upon cooling. Texture data from three weld specimens were compared to theoretical textures calculated using ideal Euler angles for shear in face centered cubic (FCC) structures transformed by the Kurdjumov–Sacks (KS) relationship. These theoretical textures show similarities to the experimental textures. Texture data from the weld specimens revealed a rotation of the shear direction corresponding to the tangent of the weld tool on both the area directly under the weld tool shoulder and weld cross sections. In addition, texture data showed that while the shear plane of the area under the weld tool shoulder remained constant, the shear plane of the weld cross sections is influenced by the weld tool pin.     

Sexual function after major resections of the sacrum with bilateral or unilateral sacrifice of sacral nerves

The sexual function of nine patients with severance of sacral nerves bilaterally (five patients) or unilaterally (four patients), performed during operations for radical extirpation of tumors of the sacrum or its vicinity, was studied. Sexual histories were obtained and sensibility tests were performed. In four of the five male patients an attempt was made to collect electromyographic recordings from the external urethral and anal sphincters during ejaculation. Bilateral loss of S3 to S5 nerves in two women seemed not to affect their sexual function. Bilateral loss of S2 to S5 nerves in one man was compatible with gratifying sexual intercourse, the stimulation for erection being purely psychogenic, and "ejaculation" of a dripping nature. Unilateral loss of all sacral nerves did not impair previously normal sexual function, although the penises and vulvae of these patients were anesthetic on one side. The sensibility of the penis seemed to be subserved by the second sacral nerve. The myoelectric activity of the striated urethral and anal sphincters during ejaculation recorded in one patient with unilateral total loss of sacral nerves was normal bilaterally considering the duration of, and intervals between, the clonic contractions.     

Zone III fractures of the sacrum. A case report

STUDY DESIGN: Case reports. OBJECTIVES: To define the radiologic characteristics, management, and results of Zone III fractures of the sacrum. SUMMARY OF BACKGROUND DATA: Zone III fractures of the sacrum are rare. There are few case reports of longitudinal fractures of the sacrum involving Zone III. METHOD: The authors report eight (four transverse, four longitudinal) Zone III fractures of the sacrum. Seven patients were treated surgically by posterior sacral decompression with or without transiliac bar fixation, and one neurologically intact patient with undisplaced longitudinal fracture was treated conservatively. RESULTS: Two neurologically compromised patients had return of normal bladder and rectal function, and another had bladder recovery only. The rest continued to show neurogenic bladder and required intermittent self-catheterization. The patient with bilateral foot drop had partial motor recovery and did not require an ankle-foot orthosis. CONCLUSIONS: These fractures may be difficult to diagnose in polytraumatized patients and require a high index of suspicion. The longitudinal fractures may not be apparent on anteroposterior radiographs, and computed tomography scan may be necessary for establishing the diagnosis. The transverse fractures may show a characteristic step ladder sign on anteroposterior radiographs when the fracture is displaced severely. Proper lateral radiographs often are difficult to obtain, particularly in obese polytraumatized patients. Routine computed tomography scan may overlook the diagnosis. Therefore 2- to 3-mm computed tomography cuts are recommended, which may show double neural foramina in presence of significant anteroposterior displacement and overriding of the fracture fragments. Sagittal computed tomography reconstructions are useful in evaluating the transverse fractures. Posterior sacral decompression is safe and probably promotes nerve root recovery. Longitudinal fractures may be stabilized satisfactorily by transiliac rod fixation.     

Anatomic relations of the thoracic pedicle to the adjacent neural structures

STUDY DESIGN: This study analyzed anatomic parameters between the thoracic pedicles and the spinal nerve roots. OBJECTIVES: To quantitatively determine the anatomic relations of the thoracic pedicle to the adjacent neural structures. SUMMARY OF BACKGROUND DATA: Pedicular screw placement carries with it potential hazard to the surrounding neural structures, especially in the thoracic spine. No studies exist regarding the anatomic relations of the thoracic pedicle to the adjacent nerve roots. METHODS: Fifteen cadavers were obtained for study of the thoracic spine. All soft tissue was dissected off the thoracic spine. Laminectomy and total removal of the superior and inferior articular facets was then performed on C7-T1 through T12-L1 to expose the pedicles, nerve roots, and dura. Measurements were taken from the pedicle to the nerve root superiorly and inferiorly as well as between the pedicles. Also, the superoinferior diameter of the nerve root and the frontal angle of the nerve root were measured. Symmetrical structures were measured bilaterally. RESULTS: The results showed that no epidural space could be found between the dural sac and the pedicle in all 15 cadavers. The average distances from the thoracic pedicle to the adjacent nerve roots superiorly or inferiorly at all levels ranged from 1.9 to 3.9 mm and from 1.7 to 2.8 mm, with a minimum of 1.3 mm, respectively. The interpedicular distance increased from T1 (13.8 mm) to T3, slightly decreased in T4-T5, then gradually increased to T12 (16.6 mm). The superoinferior diameter of the nerve root increased consistently from 2.9 mm at T1 to 4.6 mm at T11. The frontal nerve root angle decreased consistently from T1 (120.1 degrees) to T12 (57.1 degrees), except at T4-T5. CONCLUSIONS: This study suggested that more care be taken into consideration in placing a transpedicular screw in the transverse plane than in placing a screw in the sagittal plane in the thoracic spine.     

Displaced fracture of the lumbosacral spine with delayed cauda equina deficit: report of a case and review of literature

A 41-year-old man with a fracture of the upper sacrum and forward and downward displacement of the superior sacral fragment and upper spine on the lower sacrum, developed partial deficit of cauda equina function. Similar fractures rarely have been reported. Signs of lumbar pain, contusion, and fractured transverse processes should lead the surgeon to carefully examine the radiologic fractures of the area of injury; otherwise, this lesion may heal unrecognized. With the spine in flexion, the fracture may create mechanical instability. Early closed or open reduction is theoretically ideal. Surgical treatment must be weighed in terms of the risks and needs of the individual.     

Anatomical basis of autonomic nerve-preserving total mesorectal excision for rectal cancer

Total mesorectal excision with autonomic nerve preservation for rectal cancer is based on the anatomy of the mesorectum and of the pelvic autonomic nerves. Cadaver dissections were performed to describe the relationship between these structures. Between the rectum and the sacrum a retrorectal space can be developed, lined anteriorly by the visceral leaf and posteriorly by the parietal leaf of the pelvic fascia. The hypogastric nerve runs anterior to the visceral fascia, from the sacral promontory in a laterocaudad direction. The splanchnic sacral nerves originate from the sacral foramina, posterior to the parietal fascia, and run caudad, laterally and anteriorly. After piercing the parietal layer of the pelvic fascia, approximately 4 cm from the midline, the sacral nerves run between a double layer of the visceral part of the pelvic fascia. The relationship between the hypogastric nerves, the splanchnic nerves and the pelvic fascia was comparable in all six specimens examined.     

Cut-off point of the Scoliometer in school scoliosis screening

STUDY DESIGN: A large-scale study on school screening for scoliosis was conducted to assess the referral rate, prevalence rate, and positive predictive value using different angles of trunk rotation as criteria for referral. OBJECTIVE: To determine an ideal angle of trunk rotation cut-off point to be used for referral in school screening for scoliosis. SUMMARY OF BACKGROUND DATA: When using the Scoliometer (Orthopedic Systems, Inc., Hayward, CA) in school scoliosis screening, 5 degrees and 7 degrees angles of trunk rotation have been recommended as criteria for referral. Low positive predictive values and over-referral at these levels have been reported. METHODS: The Adams forward bend test and Scoliometer measurement were combined for school scoliosis screening in 33,596 girls from the fifth, sixth and seventh grades. Nurses were the primary screeners. Girls with trunk rotation angles of 5 degrees or more were referred for radiography. RESULTS: The referral rate was 5.2%. By selecting 6 degrees, 7 degrees, 8 degrees, 9 degrees or 10 degrees angles of trunk rotation as criteria for referral, the referral rate became 2.4%, 1.4%, 0.7%, 0.5%, or 0.3%, respectively. The prevalence rate for scoliosis equal to or larger than 10 degrees, 20 degrees, 30 degrees, or 40 degrees of the Cobb angle was 1.47%, 0.21%, 0.04% and 0.02%, respectively, by using a 5 degrees angle of trunk rotation as the criterion for radiography. The positive predictive value was 28.3% for scoliosis of 10 degrees or more, 4% for scoliosis of 20 degrees or more, 0.8% for scoliosis of 30 degrees or more, and 0.4% for scoliosis of 40 degrees or more with a 5 degrees angle of trunk rotation as the criterion for referral. By selecting angles of trunk rotation larger than 5 degrees as criteria for referral for radiography, the positive predictive value increased, but positive cases with larger Cobb angles also decreased markedly. CONCLUSION: The optimal cut-off point for referral when using the Scoliometer in school screening of scoliosis is still difficult to determine.     

The reliability of the lateral radiograph in determination of the optimal transarticular C1-C2 screw length

STUDY DESIGN: This study assessed the value of using lateral radiographs in evaluating the optimal screw length in transarticular C1-C2 screw fixation. OBJECTIVES: To assess the reliability of the lateral radiograph in determining the optimal transarticular C1-C2 screw length. SUMMARY OF BACKGROUND DATA: Transarticular C1-C2 screw placement is usually performed using anatomic landmarks and fluoroscopy. A lateral fluoroscopic image is valuable when directing screws in the sagittal plane, but its exact role in determining screw length has not been investigated. METHODS: Eight cervical spine specimens were used in this study. Screw placements were performed in each specimen, fixed in the exact lateral position and under direct visualization. After each placement, a lateral radiograph was taken. The odontoid process was divided into three equal portions. Another portion anterior to the odontoid process was called the anterior tubercle region. The number of screw tips appearing in each portion on the radiograph was then recorded for each placement. In addition, 30 C1 specimens were measured to evaluate the anterior part of C1. RESULTS: The results showed that 12.5% of the screws placed 2 mm short of reaching the ventral cortex and 0 mm overpenetrating the ventral cortex of the lateral mass of C1 projected in the radiograph on the anterior tubercle region, 37.5% on the anterior region of the odontoid process, and 50% on the middle region of the odontoid process. Twenty-five percent of the screws that were placed to overpenetrate, by 2 or 4 mm, the ventral cortex of the lateral mass of C1 were projected on the anterior tubercle region in the radiograph, and 50% and 62.5% were projected on the anterior region of the odontoid process, respectively. The mean vertical distance between the anteriormost point of the anterior tubercle of the anterior ring and the middle of the ventral cortex of the lateral in all specimens was 5.6 +/- 1 mm, and the mean transverse angle of the anterior ring relative to the frontal plane was 21.1 +/- 3.5 degrees. CONCLUSIONS: This results in this study indicate that a lateral radiograph may not be reliable in determining the optimal screw length, although it is valuable in directing accurate screw angle in the sagittal plane. Preoperative computed tomographic evaluation of the C1-C2 region may be helpful in estimating the location of the screw tip on the lateral radiograph during surgery.     

转炉氧枪固定与调整装置的研究及应用

为了选择1种具有较高性价比的氧枪固定与调整装置,对平面单点支撑固定法、V型块导向定位销固定法和球面自定心两点固定法3种氧枪固定与调整方法进行了对比分析。结果表明:采用球面自定心两点固定法设计的氧枪固定与调整装置成本较低且安全可靠,结构合理,换枪方便,可以达到快速更换转炉氧枪的目的。     

Role of MRI in the diagnosis of insufficiency fractures of the sacrum and acetabular roof

OBJECTIVE: To review the risk factors and the radiological appearance of insufficiency fractures of the sacrum and acetabular roof. DESIGN AND PATIENTS: Twenty patients with sacral and acetabular roof insufficiency fractures were reviewed retrospectively. There were 16 women (80%) and 4 males (age range 48-86 years, excluding an 8-year-old boy). Thirteen patients had a known tumour, and nine had received pelvic irradiation. All patients, except one who was asymptomatic, presented with low back or hip pain. In patients with a known tumor, metastases were suspected. Plain radiography (20), bone scintigrams (16), MR examinations (20), and bone densitometry (14) were performed. Nine patients also each had a CT scan. RESULTS AND CONCLUSIONS: In three cases the CT scan performed 10-25 days after onset of symptoms was interpreted as normal. MR examination performed a few days after the CT scan showed in each of these three patients a fracture line with a band of edema. Scintigraphy was very sensitive, but the H-shaped pattern of sacral uptake, specific for an insufficiency fracture, was detected in only three of 16 cases. The earliest MR sign was medullary edema, seen as early as 18 days after the onset of symptoms. On spin echo (SE) T1-weighted images (T1WI), the hypointense signal of edema could mask a fracture line. On SE T2WI the fracture line could be detected within the hyperintense edema (10 of 17 patients with examinations including SE T2WI). However, in four patients a fracture of the sacrum was not seen on T2WI, these having been obtained in the axial plane. For this reason, intravenous gadolinium was injected, revealing a fracture line in 12 of 14 examinations, or fat suppression sequences were performed, revealing a fracture line in five of five cases. The total number of fractures detected was 17 [15 fractures of the sacrum (bilateral in 10 cases) and two of the acetabular roof]. At a later stage, the edema resolved and the fracture was clearly seen. The two cases of fracture of the acetabular roof were easily recognized at MRI, particularly in the sagittal plane.     

Gunshot injuries of the sacrum

Gunshots to the sacrum are unusual and present several management problems. Associated injuries and particularly sacral bleeding are troublesome. Conventional methods of hemostasis are not suitable in this setting as the spinal blood supply is very complex because it is largely derived from the longitudinal spinal arteries originating intracranially. Attempts at proximal control are difficult and could lead to neurological injury. We successfully managed brisk bleeding in three patients with sacral gunshots. After the major intra abdominal hemorrhage had been controlled, attention was turned to the sacral wounds that had been packed with sponges up to that time. The sacral defect was closed with bone wax to control bleeding definitively. Methyl cellulose was then put over the bone wax and the periosteum of the sacrum and posterior peritoneum (mobilized if necessary), sutured over the methyl cellulose. Post operatively the patients are carefully monitored for developing neurological deficit that would necessitate immediate sacral laminectomy and decompression. We advocate tamponading of the sacral wound with bone wax, covered by methyl cellulose and kept in place and held firm by the periosteum and posterior peritoneum sutured over it as a successful interim or definitive form of therapy.