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At least 19 recordsLinked to original sources
PubMed2003

[Clinical application of universal spine system in reconstruction of lumbar sacrum joint after resection of sacrum tumor].

OBJECTIVE: To investigate the operative indications and techniques of the universal spine system (USS) in reconstruction of the stability of the lumbar-sacrum joint after resection of sacrum tumor. METHODS: Nine patients were treated with USS after resection of sacrum tumor. Among them, there were 6 males and 3 females, aged from 34-60 years. The operation could be divided into four main procedures: 1. to resect sacrum tumor; 2. to insert the pedicle screw into the normal pedicle (L3 or L4 or L5) above the region of laminectomy; 3. to insert the lower screw into the iliac plate; 4. to put the rods, bone graft and links. RESULTS: There was no recurrence of sacrum tumor by MRI examination during 7-17 month follow-up. The pains of the lumbar-sacrum joint and the spinal nerve root were relieved obviously. The patients could stand and walked normally. There was no loose screw and no fracture of the screw and the rod. There was no appearance of the enlarged screw passage, the lessened pelvis and lowed L5 spine. CONCLUSION: Reconstruction of the lumbar-sacrum joint by the USS after resection of sacrum tumor is a practical operation clinically. It is characterized by the easy manipulation, few complication and stable fixation.

Adult↗
PubMed2004

[Therapy of unstable sacrum fractures in pelvic ring fractures with dorsal sacrum distraction osteosynthesis].

Unstable pelvic ring injuries AO type C ("vertical shear") with a fractured sacrum are treated operatively in less than 50% of the cases (DGU pelvis study group). Furthermore, only 12% of these ORIF involve the sacrum bone itself. No specific technique has gained wide acceptance in treating transsacral instability. In accordance with earlier publications (Käch, Josten) suggesting an internal fixator, we developed the dorsal sacrum fracture distantly anchored ORIF (DSDO). This procedure closes the dorsal pelvic ring by joining the two dorsal iliac crests (fixed-angle screws inserted in the posterior superior iliac spine) and additionally anchors in a lumbar pedicle. Thus, a three-dimensional reduction and stable fixation device with optional local nerve decompression and even plating possibility is achieved. Between January 1996 and July 2001, 35 unstable sacrum disruptions were treated with DSDO in 180 patients operated for pelvic trauma. This allowed immediate mobilization in all cases. The radiologic follow-up examination ( n=20) revealed a solid union in all patients. Complications focused on management of the soft tissue degloving injury (Morel-Lavalleé lesion), which needs special attention.

Adolescent↗
PubMed2006

Assessment of sacrum scalloping in neurofibromatosis type 1 caused by a giant cell lesion of the sacrum.

BACKGROUND: Neurofibromatosis type 1 (NF-1) is the most common of the neurocutaneous disorders. It leads to significant orthopedic complications and spinal deformities. Scalloping in NF-1 may be caused by weakness of the mesodermal dysplasia, which develops through the inherited mutation of chromosome 17. Aneurysmal bone cysts (ABCs) are rare, rapidly expanding, locally destructive, and often misdiagnosed lesions. Assessment of sacrum scalloping in NF-1 caused by aneurysmal bone cyst is described. CASE DESCRIPTION: A 15-year-old male was a patient with NF-1. He presented with cramping pain of the left soleus muscle, which had developed over the previous 3 months. The magnetic resonance imaging of the lumbar-sacrum region revealed a well-circumscribed multiloculated lesion located in the dorsal sacrum region and causing posterior vertebral scalloping and compression of nerve roots. The preoperative clinical suspicion was of a neurofibroma, a giant cell granuloma, or a lymphoma. However, the histopathologic diagnosis was consistent with ABC of the sacrum. This differed from our preoperative suspicion. CONCLUSION: The etiology of ABCs is still unknown. Some researchers have described ABCs with chromosomal abnormalities of 16q22 and/or 17p13. This is consistent with NF-1, which develops through the inherited mutation of chromosome 17. Therefore, mutation of the chromosome may play an important role in the development of NF-1 and ABCs. Adequate diagnosis is necessary before treatment or biopsy of ABCs because bleeding may occur during operation or biopsy. Surgery is the treatment of choice for most ABCs. Adjuvant megavoltage radiotherapy is indicated for patients with recurrent tumors and whose tumors are inoperable.

Adolescent↗
PubMed2004

Long adult deformity fusions to L5 and the sacrum. A matched cohort analysis.

STUDY DESIGN: A matched cohort analysis of long adult deformity fusions according to distal fusion level (L5 vs. S1). OBJECTIVE.: To compare the results of long adult deformity fusions to either L5 or the sacrum in the presence of a "healthy" 5-1 disc using a matched cohort analysis. SUMMARY OF BACKGROUND DATA: For adult spinal deformity, the decision often arises whether to terminate a long fusion at L5 or the sacrum. The decision is especially challenging in the presence of a "healthy" (Grade 0 to 1 degeneration) 5-1 disc. MATERIALS AND METHODS: A total of 95 adult deformity patients that underwent fusion from the thoracic spine to either L5 or the sacrum were sorted according to five preoperative criteria: 5-1 disc status, patient age, smoking status, number of levels fused, and sagittal balance. Two cohorts (L5, 27 patients; sacrum, 12 patients) were precisely matched according to the five criteria. Patients were evaluated at 2-year minimum follow-up according to radiographic data, complications, and SRS-24 outcomes. RESULTS: Correction of sagittal imbalance was superior for sacrum patients (C7 plumb line: L5, 0.9 cm; sacrum, 3.2 cm; P = 0.03). At latest follow-up (L5, 5.2 years; sacrum, 3.7 years), 67% of L5 patients had radiographic evidence of advanced 5-1 disc degeneration and the L5 cohort tended to have inferior sagittal balance (C7 plumb line: L5, +4.0 cm; sacrum, +1.2 cm; P = 0.06). The sacrum cohort, however, required more surgical procedures (L5, 1.7; sacrum, 2.8; P = 0.03) and experienced a greater frequency of major complications (L5, 22%; sacrum, 75%; P = 0.02), including nonunion (L5, 4%; sacrum, 42%; P = 0.006) and medical morbidity (L5, 0%; sacrum, 33%; P = 0.001). SRS-24 scores reflected a similar patient assessment of outcome and function for the two cohorts (L5, 89; sacrum, 87). DISCUSSION AND CONCLUSION: At 3 to 5 years' mean follow-up, long adult fusions to the sacrum required more procedures and had a higher frequency of complications than similar fusions to L5. For fusions to L5, subsequent subjacent disc degeneration is common and may be associated with a forward shift in sagittal balance. The ultimate influence of these factors on long-term outcomes remains to be seen.

Adult↗
PubMed2002

The sagittal anatomy of the sacrum among young adults, infants, and spondylolisthesis patients.

The anatomic pelvic parameter "incidence" - the angle between the line perpendicular to the middle of the sacral plate and the line joining the middle of the sacral plate to the center of the bicoxo-femoral axis - has been shown to be strongly correlated with the sacral slope and lumbar lordosis, and ensures the individual an economical standing position. It is important for determining the sagittal curve of the spine. The angle of incidence has also been shown to depend partly on the sagittal anatomy of sacrum, which is established in childhood while learning to stand and walk. The purpose of this study was (1) to define the relationship between the sacrum and the angle of incidence, and (2) to compare these parameters in three populations: young adults, infants before walking, and patients with spondylolisthesis. Forty-four normal young adults, 32 infants not yet walking and 39 patients with spondylolisthesis due to isthmic spondylolysis underwent a sagittal full-spine radiography. A graphic table and the software for bidimensional study of the sacrum developed by J. Hecquet were used to determine various anatomic and positional parameters. Comparison tests of means, and multiple and partial correlation tests were used. A study of the reliability of the measurements using factorial plan methods was performed. The sagittal anatomic parameters of the sacrum were found to have a close relationship with the pelvic parameter of incidence angle, and therefore with the sagittal balance of the spine. The anatomy of the sacrum in spondylolisthesis patients is particular in that some features are much like those of young infants, but it is more curved and the incidence angle is significantly larger. There is a close relationship between angle of incidence and the slip of spondylolisthesis. All the parameters of young infants are significantly smaller than those of adults. It can be concluded that the sagittal anatomy of the sacrum plays a key role in spinal sagittal balance. The sacral bone is an integral a part of the pelvis and constitutes the undistorted part of the spinal curves. Organization of sagittal curves during growth can be followed up by looking at the sacrum. The sacrum in the spondylolisthesis group differs from the normal, and the greater angle of incidence and sacral slope in this group could predispose to vertebral slip.

Adolescent↗
PubMed2000

Internal architecture of the sacrum in the elderly. An anatomic and radiographic study.

STUDY DESIGN: A description of the internal architecture of the sacrum, including its trabecular arrangement, cortical thickness, and overall bone density. OBJECTIVES: To determine the strong and weak areas in the sacrum to understand more clearly the sacral structure and its clinical implications. METHODS: First, seven cadaveric sacral specimens were sectioned in different planes. Horizontal sections were performed at the upper S1, middle S1, S2, S3, and S4. Sagittal sections were made through the median sacral crest, the sacral foramina, and medial to the articular surface. A coronal section through the whole length of a sacral specimen was produced. All sections were studied radiographically, and the trabecular pattern was analyzed. In the second part of the study, axial computed tomography scans of 40 dry sacrum specimens were analyzed by using the National Institutes of Health Image 1.61 program. The cortical thickness and bone density were determined. RESULTS: In the upper sacrum, three distinctive distributions of bony trabeculae were noted, one extending from the center of the sacral body anterolaterally, and the other two extending from the pedicle toward the auricular surface. A condensation zone was observed at the intersection of these trabeculae and was located at the anterior cortex of the foraminal zone. The junction between S2 and S3 represented a weak area with abrupt disappearance of the condensation zone. Analysis of the bone density of the sacrum using the plot analysis demonstrated that, at S1 and S2, the anterior cortex of the foraminal zone (condensation zone) is the most compact part of the sacrum. CONCLUSION: These results suggest that the strongest part of the sacrum is the anterior cortex above the foramina in S1 and S2. The weakest point of the sacrum was found to lie at the level of the junction of S2 and S3.

Aged↗
PubMed2001

Complications and results of long adult deformity fusions down to l4, l5, and the sacrum.

STUDY DESIGN: This is a consecutive study of patients having undergone surgical treatment of adult lumbar scoliosis. Follow-up ranged from 2 to 13 years (average 5 years). OBJECTIVES: To assess the complications and outcomes of patients with long fusions to L4 (n=23), L5 (n=21), or the sacrum (n=15) and determine if a "deeply seated" L5 segment is protective. SUMMARY OF BACKGROUND DATA: Few studies assess outcomes and complications in adults fused from the thoracic spine to L4, L5, or the sacrum with minimum 2-year follow-up. METHODS: Fifty-eight patients (59 cases; average age 43 years; range 21 to 60) with minimum 2-year follow-up were analyzed for subsequent spinal degeneration and complications. Outcomes were assessed from questionnaires administered at latest follow-up. RESULTS: Sixteen percent of cases (7 of 44) fused short of the sacrum displayed subsequent postoperative distal spinal degeneration, although only three patients were symptomatic. Compared with the group with no subsequent degeneration, this group had a lower improvement in function and pain relief. Other complications for patients fused short of the sacrum included two cases with crosslink breakage, one with neurologic deficit, three with pseudarthroses, one with hook pullout, and one with L5 screw pullout. For cases fused to the sacrum, two cases with deep wound infections and one with loose iliac screw requiring removal were observed. Because two of four cases fused to L5 with subsequent degeneration at L5-S1 were observed to have "deeply seated" L5 segments and two of the four did not, the authors could conclude only that "deep seating" of L5 is not absolute protection. CONCLUSIONS: Fusions short of the sacrum did not have predictable long-term results. Those fused short of the sacrum who developed distal spinal degeneration had worse outcomes. Patients fused to the sacrum did not have a higher complication rate. A "deeply seated" L5 segment does not necessarily protect the L5-S1 disc.

Adult↗
PubMed2006

Osteochondroma of the sacrum: a case report and review of the literature.

STUDY DESIGN: A case report and review of the literature. OBJECTIVES: To describe the en bloc excision and postoperative outcome of an osteochondroma of the sacrum compressing the neural elements, as well as review the literature on solitary osteochondroma involving the sacrum. SUMMARY OF BACKGROUND DATA: Osteochondroma is the most common primary benign bone tumor. However, this tumor rarely involves the spine and even more rarely involves the sacrum. To the best of our knowledge, en bloc excision of a solitary osteochondroma of the sacrum has not been previously reported. METHODS: An 11-year-old male presented with disabling radicular pain in the right lower extremity. Radiologic studies showed a lesion occurring from the sacral lamina that was compressing the S2 nerve root. The tumor was excised en bloc through a posterior approach. The cavitary defect within the sacrum was reconstructed with crushed cancellous allograft and demineralized bone matrix putty. A literature review of solitary sacral osteochondroma was conducted of the English-based medical literature. RESULTS: Histologic studies showed the tumor to be an osteochondroma. After surgery, pain was completely relieved, and neurologic function was normal. At the last follow-up, the sacroiliac joint remained intact, and there was no evidence of local recurrence. A literature review revealed 4 previous cases addressing osteochondroma of the sacrum. CONCLUSIONS: Osteochondroma is a rare primary benign bone tumor that can occur in the sacrum. Local contamination and, therefore, the likelihood of local recurrence, are decreased when an en bloc, as opposed to an intralesional, excision is performed.

Child↗
PubMedDate not supplied

The sacrum: pathologic spectrum, multimodality imaging, and subspecialty approach.

The sacrum is a structure that is imaged by both general and subspecialty radiologists. A wide variety of disease processes can involve the sacrum either focally or as part of a systemic process. Plain radiographs, although limited in evaluation of the sacrum, should be carefully examined when abnormalities of the sacrum are suspected. Cross-sectional imaging, particularly computed tomography and magnetic resonance (MR) imaging, plays a crucial role in identification, localization, and characterization of sacral lesions. Congenital lesions of the sacrum, including sacral agenesis and meningocele, are optimally imaged with MR. The most common sacral neoplasm is metastatic disease. Primary neoplasms of the sacrum, which include giant cell tumor, chordoma, and teratoma, are infrequent. Infection of the sacrum or sacroiliac joint is most often due to contiguous spread from a suppurative focus. A wide variety of arthritic disorders such as ankylosing spondylitis and osteoarthritis can involve the sacroiliac joints as part of a localized or systemic process. Sacral fractures related to acute trauma or repetitive stress are difficult to diagnose and treat. Knowledge of these abnormalities and familiarity with the imaging of these processes will allow radiologists of all subspecialties to contribute to the diagnosis and management of sacral disorders.

Diagnosis, Differential↗
PubMed1992

[The problem of the sacrum fracture. Clinical analysis of 377 cases].

Sacral fractures are rare injuries that are often neglected because of the general severity of the patient's injuries. They are typical injuries in patients with polytraumata. A "hidden" injury, they are often diagnosed late or are even missed. In a well-documented consecutive series of 1,350 patients with pelvic fractures treated in the trauma department of the Hannover Medical School between 1972 and 1991, a total of 377 sacrum fractures were evaluated in a retrospective study. The cause of the accident, mechanism of injury, concomitant injuries, diagnostic procedures, classification of the pelvic injury (TILE), as well as the classification of the sacrum injury (DENIS), treatment and outcome were analyzed in all cases. Observed complications with special attention to injuries to the lumbosacral plexus were correlated with the classification of the sacrum and pelvis, as well as with a detailed analysis of the fracture pattern and fracture characteristics. In 89.4% at least one additional body region was injured in these patients. PTS (Hannover Polytrauma Score) groups III and IV included 42.5% of the patients. With an improved diagnostic protocol (radiological a.p. views, oblique views and CT scan), the observed rate of sacrum fractures was 33%. Neurological deficits occurred in 15.1% of the patients. In contrast to the literature, the rate of neurological deficits was related more to the degree of pelvic instability (TILE) than to the specific fracture pattern in the sacrum. In stable injuries (TILE A) neurological deficits were only seen in exceptions. In type B injuries the maximum rate was 10%, whereas in unstable fractures (TILE C) the rate of neurological deficits was 32.6% in transalar fractures (DENIS zone I), 42.9% in transforaminal fractures (DENIS zone II), and 63.6% in central fracture types (DENIS zone III). Additional risk indicators for neurological impairment are avulsion fractures of the sacrum, comminuted and bilateral fracture lines. The fracture classification should thus be modified. Our own experience with operative therapy for sacral fractures (open revision of the sacral plexus together with internal stabilization of the fracture) is still limited, but based on the experience presented, further development of the treatment protocol for sacrum fractures should be considered.

Adolescent↗
PubMed2005

Coronal oblique turbo STIR imaging of the sacrum and sacroiliac joints at routine MR imaging of the lumbar spine.

The objective of the study was to evaluate the clinical impact of coronal oblique imaging of the lumbrosacral junction and the sacrum at initial presentation for MR imaging of the lumbar spine in patients presenting with low back pain or sciatic pain. Two hundred and sixty consecutive patients attending for MRI of the lumbar spine underwent simultaneous coronal oblique turbo short tau inversion recovery (STIR; TR 2500, TE 40, TI 150, echo train length 7, number of scan acquisitions 2) imaging of the sacrum and the sacroiliac joints with a field of view of 30-cm and 3-mm slices (acquisition time 3 min and 20 s). Images were reviewed by two experienced radiologists to determine the cause of back pain, with and without images of the sacrum and sacroiliac joints. The added value of the additional sequence was assessed. Correlation was made with surgery, response to nerve root injection or clinical follow-up at 3 months. Subgroup analysis was performed to determine if patient stratification according to sex or symptoms would be useful. In total, in 19 of 260 patients (7.3%), abnormalities were identified at coronal STIR imaging. In 7 of 260 patients (2.7%), pathology was identified in the sacrum thought to account for back pain, altering the diagnosis made on the standard sequences. These diagnoses were sacroiliitis (n=2), sacral stress fracture (n=1), degenerative sacroiliac joints (n=1), degenerative accessory articulation between the lumbar spine and the sacrum (n=1), Tarlov cyst of nerve root (n=1) and retroverted uterus causing sciatic pain (n=1). Patient stratification according to sex or the presence or absence of sciatic symptoms was not useful in predicting the added benefit of the additional sequence. Routine coronal STIR imaging of the sacrum as part of lumbar spine MRI improves assessment of patients presenting with low back pain or sciatica in only a small number of patients.

Acute Disease↗
PubMed1998

The internal bony architecture of the sacrum.

STUDY DESIGN: Radiographic and direct quantitative measurements were made of the cortical and the trabecular anatomy of the sacrum. OBJECTIVES: To define the trabecular patterns and the cortical thickness of the sacrum. SUMMARY OF BACKGROUND DATA: The sacrum is a frequent site of internal fixation. In previous anatomic studies, investigators have focused on specific dimensional measurements of the sacrum, whereas others have described the anatomic course of the anterior sacral neurovascular or visceral structures. Computed tomographic imaging also has been used to quantify the sacral trabecular bone density. The internal architecture of the sacrum has yet to be described in detail. METHODS: Seventeen cadaveric sacra were studied by computed tomographic imaging and then were sectioned at 3-mm intervals in the axial or sagittal plane. The cortical thickness of each section was measured under microscopic visualization. The sections were radiographed with high-resolution imaging to delineate their trabecular patterns. RESULTS: The trabecular bone was densest adjacent to the endplates. The sacral body trabeculae were arranged in a cruciate pattern, and bony atrophy occurred in a systematic fashion. An alar void was a consistent finding in all specimens with definable boundaries. The cortical thickness was uniform throughout the surface of each specimen. The computed tomographic images correlated with the anatomy observed in the cadaveric sections. CONCLUSION: The internal bony architecture of the sacrum has several consistent features. The relatively uniform cortical thickness seen in each sacral specimen may have clinical significance in the internal fixation of this region.

Aged↗
PubMed2002

Multimodality management of a giant cell tumor arising in the proximal sacrum: case report.

STUDY DESIGN: Descriptive. OBJECTIVE: To outline a novel multimodality approach for a difficult surgical resection of a giant cell tumor in the cephalad portion of the sacrum. SUMMARY OF BACKGROUND DATA: Giant cell tumors of the sacrum are rare primary bone tumors. Recent reports have demonstrated diminished giant cell tumor recurrence with cryosurgery by using a "direct pour" technique with liquid nitrogen. Although successful in decreasing tumor recurrence, this technique is accompanied by a 4%-8% rate of skin necrosis and high rates of pathologic fracture. The authors describe resection and a novel, controlled method of argon-based cryotherapy (followed by a unique pelvic reconstruction) for a large, difficult giant cell tumor of the sacrum. METHODS: A 29-year-old woman presented with complaints of right foot drop and decreased sensation of the right buttock, posterior thigh, posterior calf, and lateral aspect of the right foot. Radiographic evaluation revealed a mass in the right sacrum; histologic examination of CT-guided biopsy revealed a giant cell tumor. A combined anterior abdominal and posterior sacral approach was performed, the tumor was resected, and the margin of the cavity was treated with controlled argon-based cryotherapy. The combination of thermocouples, electromyographic monitoring, and rapid freeze-thaw cycles allowed a controlled ablation of the tumor margin while ensuring that surrounding structures, such as the rectal wall, sacral nerves, and gluteal muscles, were not damaged. Posterior spinal fusion L4 to sacrum, posterior spinal instrumentation L4 to pelvis, and allograft reconstruction of the right sacrum were performed. RESULTS: The patient recovered well without skin necrosis or pathologic fracture. Urinary and fecal continence were preserved. At the 20-month follow-up the patient has no evidence of local tumor recurrence and is fully ambulatory without a brace or narcotic medication. CONCLUSION: A novel multimodality approach, consisting of resection, controlled cryosurgery, and a unique lumbopelvic reconstruction, was safe and successful in managing a challenging proximal sacral giant cell tumor. Twenty months after surgery the patient has excellent bowel and bladder control, no tumor recurrence, and functional ambulation without a brace or pain.

Adult↗
PubMed2005

Stress fracture of the pelvic wing-sacrum after long-level lumbosacral fusion: a case report.

STUDY DESIGN: A case report of transverse stress fracture of the pelvic wing-sacrum after long-level lumbosacral fusion. OBJECTIVE: To report this rare complication of long-level lumbosacral fusion. SUMMARY OF BACKGROUND DATA: There are a number of well-described complications of instrumented lumbosacral fusion, including delayed stress fracture of the pelvis. A bilateral pelvic wing-sacrum transverse stress fracture after long-level lumbosacral fusion has not been previously reported to our knowledge. METHODS: Radiography and computed tomography were used to confirm the diagnosis. Long lumbosacral fusion and a pelvic wing-sacrum fracture were shown. RESULTS: A 48-year-old woman underwent several revision spinal surgeries for collapse or instability occurring at the adjacent levels. She presented with low back and bilateral buttock pain with slow progression after last surgery. A bilateral transverse pelvic wing-sacrum stress fracture was found on plain radiographs 7 months later. CONCLUSIONS: Stress fracture of bilateral pelvic wing-sacrum can occur as a potential source of late pain after long fusions of the lumbosacral spine. A better understanding of the related biomechanical forces and preoperative risk factors may identify patients at risk and may aid in surgical planning. There are few reports of pelvic stress fracture as a complication of lumbosacral fusion, and it is typically described as a late occurrence. We present the occurrence of a bilateral pelvic wing-sacrum transverse stress fracture, not previously discussed to our knowledge.

Female↗
PubMed1989

Weight transmission through the sacrum in man.

An attempt has been made to find the route and relative magnitude of weight passing through different components of the sacrum. In 44 adult male dry sacra, the combined surface area of the body and the two facets was compared with the combined surface area of the two auricular surfaces. It was found that the forces acting on the body and articular facets, at the upper end of the sacrum, are ultimately transmitted through the two auricular surfaces with an appreciable part of the load passing directly from the transverse process of the fifth lumbar vertebra to the ala of the sacrum through the lumbosacral ligament. The direction of the trabecular bone indicates the route of load transmission in the sacrum. From the various parts of the sacrum (body, facets, alae and laminae) distinct sets of trabeculae extend towards the auricular surface. Observations on the sacra with the anomalous articular processes provided strong evidence for the role of the neural arch elements in the load transmission. In specimens where the articular facet was absent on one or both sides, there was always an accessory facet on the ala of the sacrum so that the load was transmitted to this facet from the transverse process of the fifth lumbar vertebra.

Adult↗
PubMed1987

Evolution of the sacrum in hominoids.

In order to study the formation of the sacrum during the primate evolution, a new way of numbering mammalian vertebrae is presented; this demonstrates that the thoracolumbosacral complex is fixed at 22 vertebrae in 80% and at 22 +/- 1 in 100% of the cases. The shift of a vertebra from one type to another occurs either at the thoracolumbar or at the lumbosacral junction and not at the cervicothoracic junction. Rarely does the shift take place at the sacrococcygeal junction. Data from 318 primates reveal that the seven original lumbar vertebrae of the Old World monkeys are reduced in the great apes by a caudad "thoracization" of one to two lumbar vertebrae and a cephalad sacralization of one to four lumbar vertebrae. In the apes, sacralization is not total and different stages that are intermediate between lumbar and sacral are described. In Homo sapiens there is a total sacralization of the last two original lumbar vertebrae. In addition, development of the sacral wings (alae) is minimal in apes and reaches its maximum in hominids. The tendency of the hominoid sacrum to incorporate the last lumbar vertebrae and to widen markedly provides for an enhanced articulation of the sacrum with the ilium and offers a firm base of support for the trunk during erect posture. This is necessary for the support of the weight of the trunk above the sacrum and for the stabilization of the body during bipedal posture and locomotion. Encephalization did not play any major role in the widening of the sacrum since the former by far preceded the latter.

Animals↗
PubMed2005

Morphometry of the sacrum for clinical use.

Degenerative disease and instability in the lower lumbar spine may necessitate fusion and stabilization supplemented by instrumentation to the sacrum. However, screw placement in a reasonable position is more difficult to achieve because of the unique anatomy of the first sacral (S1) vertebra. Therefore, this study has been conducted to evaluate sacrum anatomy of the Western Anatolian population in terms of morphometric measurements and make a comparison with previous studies as well as giving a guidance to the surgeons. In this study, 60 dry adult sacrums (30 male and 30 female) were assessed for morphometric analysis. The measurement data for the sacrum and S1 vertebra revealed that there was no significant difference between both sexes except the sacral width and sacral canal width (p<0.05). In the present study, the ratio of S1 corpus' width to sacral width was lower in females compared with males. A detailed knowledge of the morphometric data about sacrum is very important for spinal surgery, as pedicle screw insertion is crucial in spinal instrumentation in order to prevent neurological injury and/or fixation failure.

Adult↗