Sacral Stress Fracture Developing after Lumbosacral Fusion in a Patient with Spondylolisthesis: A Case Report

STUDY DESIGN: Case report OBJECTIVES: To report a case of sacral stress fracture that developed after lumbosacral fusion. SUMMARY OF LITERATURE REVIEW: Sacral stress fractures rarely develop after lumbosacral fusion, and osteoporosis, female sex, being over 60 years old, and long segment fusion are known risk factors. MATERIALS AND METHODS: A 66-year-old woman with spondylolisthesis at L5 on S1 underwent posterior lumbar interbody fusion and posterior instrumentation. A sacral stress fracture was found 4 weeks after the first operation, and we performed posterior reduction and posterior instrumentation with S2 alar screws. RESULTS: The patient was free from symptoms and no further displacement was found at 3 months after the last operation. CONCLUSIONS: Sacral stress fracture after lumbosacral fusion can be treated with posterior reduction and posterior instrumentation with S2 alar screws.

The Effect of Sacral Alar Screw on Long-level Fusion Including Lumbosacral Segment

STUDY DESIGN: This is a retrospective study. OBJECTIVES: To evaluated the clinical and radiological effectiveness of sacral alar screws for augmentation of S1 pedicle screws in long-level fusion including L5-S1 segment. SUMMARY OF LITERATURE REVIEW: The fusion rates of lumbosacral junction in long-level fusion are various when S1 pedicle screws are used without augmentation. But, reports of sacral alar screw augmentation are rare. MATERIAL AND METHODS: From 1996 to 2005, 63 patients performed more than two-level fusion including lumbosacral junction were reviewed. 47 patients underwent lumbosacral fusion with S1 pedicle screws only (S1 group), and 16 patients with sacral alar screws augmentation in addition to S1 pedicle screws (S1-2 group). Radiologically, bony union, halo sign, and breakage of implants were evaluated. Clinically, complications associated with screw placement and general complications were evaluated. RESULTS: Bony union was obtained in 56 cases(89%) at postoperative 4.3 months. Nonunion was observed in 7 cases(11%, S1 group:5, S1-2 group:2). Loosening of S1 pedicle screw was observed in 32 cases(89%) of S1 group and in 4 cases(25%) of S1-2 group. It showed statistical significance between two groups. Sacral alar screw loosening occurred in 8 cases(50%) of S1-2 group. Metal breakage was developed in 2 cases of S1 group without nonunion or loosening. Postoperative infection occurred in 7 cases(11%, S1 group:5, S1-2 group:2). CONCLUSIONS: Sacral alar screw augmentation was effective on protecting the loosening of S1 pedicle screw. Additional sacral alar screw can improve the rate of fusion for lumbosacral junction despite no statistical significance.

The Trajectory of Iliac Screw in the Axial Plane in 200 Korean Patients

STUDY DESIGN: A retrospective radiographic analysis. PURPOSE: To estimate the accurate trajectory in the axial plane for iliac screw insertion in 200 Korean patients using radiographic images. OVERVIEW OF LITERATURE: Several complications have been encountered after fusion to the lumbosacral junction, including pseudarthrosis, S1 screw loosening, and sacral fractures. Iliac screw fixation is considered an efficient method for augmenting sacral screw fixation but there are few reports on the trajectory of iliac screw insertion. The trajectory in the sagittal plane can be visualized by intraoperative fluoroscopy. However, there is no method to check the accuracy of the trajectory in the axial plane during surgery. METHODS: Between January 2007 and February 2009, 200 patients (107 men and 93 women) who underwent L-spine computed tomography were enrolled in this study. The mean age of the patients was 55.6 +/- 18.3 years (range, 13 to 92 years). The spino-iliac angle (SIA) was measured on the axial image at the S1 level, which was defined as the angle between a vertical line through the center of the spinous process and an oblique line that passed through the center of the outer and inner cortices of the ilium. RESULTS: The group mean SIA was 30.1degrees +/- 7.8degrees; 30.1degrees +/- 7.7degrees for men and 29.9degrees +/- 81.1degrees for women. There was no significant difference according to gender or age (p > 0.05). CONCLUSIONS: The SIA for the axial trajectory of iliac screws is approximately 30degrees in Korean patients.

A Mid-Term Follow-Up Result of Spinopelvic Fixation Using Iliac Screws for Lumbosacral Fusion

OBJECTIVE: Iliac screw fixation has been used to prevent premature loosening of sacral fixation and to provide more rigid fixation of the sacropelvic unit. We describe our technique for iliac screw placement and review our experience with this technique. METHODS: Thirteen consecutive patients who underwent spinopelvic fixation using iliac screws were enrolled. The indications for spinopelvic fixation included long segment fusions for spinal deformity and post-operative flat-back syndrome, symptomatic pseudoarthrosis of previous lumbosacral fusions, high-grade lumbosacral spondylolisthesis, lumbosacral tumors, and sacral fractures. Radiographic outcomes were assessed using plain radiographs, and computed tomographic scans. Clinical outcomes were assessed using the Oswestry Disability Index (ODI) and questionnaire about buttock pain. RESULTS: The median follow-up period was 33 months (range, 13-54 months). Radiographic fusion across the lumbosacral junction was obtained in all 13 patients. The average pre- and post-operative ODI scores were 40.0 and 17.5, respectively. The questionnaire for buttock pain revealed the following: 9 patients (69%) perceived improvement; 3 patients (23%) reported no change; and 1 patient (7.6%) had aggravation of pain. Two patients complained of prominence of the iliac hardware. The complications included one violation of the greater sciatic notch and one deep wound infection. CONCLUSION: Iliac screw fixation is a safe and valuable technique that provides added structural support to S1 screws in long-segment spinal fusions. Iliac screw fixation is an extensive surgical procedure with potential complications, but high success rates can be achieved when it is performed systematically and in appropriately selected patients.

Clinical Results and Changes of Adjacent Segment after Whole Lumbosacral Fusion / 대한정형외과학회잡지

PURPOSE: To analyze the clinical and radiological results of whole lumbosacral fusion, and to identify whether an extension of the fusion level is required. MATERIALS AND METHODS: A retrospective review was carried out on 40 patients who had undergone whole lumbosacral fusion. The adjacent segment changes were evaluated by the radiological findings including intervertebral space narrowing, traction spur, endplate sclerosis and vacuum phenomenon. The clinical results were evaluated using a visual analogue scale (VAS) and Oswestry disability index (ODI). RESULTS: The mean age was 63.8 years and the mean follow-up period was 41.7 months. At the last follow-up, adjacent segment changes were observed in 12 cases of intervertebral space narrowing, 15 cases of traction spur, 20 cases of endplate sclerosis and 8 cases of vacuum phenomenon. In the clinical results, the VAS was improved to 4.0 points from 7.6 points, and the ODI improved to 43.9% from 86.0%. There were no revision cases due to adjacent segment problems. CONCLUSION: Whole lumbosacral fusion in spinal stenosis with degenerative lumbar scoliosis was concomitant with some adjacent segment problems, but presented favorable outcomes. For the prevention of junctional problem, caution should be taken when extending the fusion level to the proximal level in whole lumbosacral fusion.

The Causes of Revision Arthrodesis for the Degenerative Changes at the Adjacent Segment after Lumbosacral Fusion for Degenerative Lumbar Diseases / 대한척추외과학회지

STUDY DESIGN: A Retrospective study OBJECTIVES: To analyze the causes of revision arthrodesis for the degenerative changes at the adjacent segment after lumbosacral fusion for degenerative lumbar diseases. SUMMARY OF LITERATURE REVIEW: Revision arthrodesis is quite common. However, there is some controversy regarding the causes and risk factors. MATERIALS AND METHODS: Twenty cases who had undergone revision arthrodesis after lumbosacral fusion were examined. Preexisting degenerative changes to the adjacent segment, location of the adjacent segment and extent of fusion, as well as changes in lumbar lordosis were observed in primary arthrodesis, and the relationship between the changes in the adjacent segment degeneration were analyzed in terms of the area of residence, activity level and living pattern of the patients. RESULTS: Preexisting degenerative changes in the adjacent segment were observed in 14 cases and degenerative changes developed at the proximal junction in 19. Multiple segment fusion were performed in 13 cases during primary arthrodesis, 9 cases developed degenerative changes at the proximal junction. Fifteen cases with abnormal postoperative lumbar lordosis demonstrated adjacent segment degeneration. Sixteen cases living in the countryside and 15 cases with a history of severe physical labor after the primary operation showed degenerative changes in the adjacent segment before secondary arthrodesis. CONCLUSION: The causes of revision arthrodesis for the degenerative changes at the adjacent segment are believed to be preexisting degenerative changes in the adjacent segment at the proximal junction, loss of lordosis after primary fusion, and severe physical labor from living in the countryside

Surgery for Adjacent Segment Changes after Lumbosacral Fusion / 대한척추외과학회지

PURPOSE: To report upon surgical outcome in terms of adjacent segment changes after lumbosacral fusion and to analyze for risk factors indicating early surgical intervention for adjacent segment changes. MATERIAL AND METHODS: This was a retrospective study of twenty patients who underwent revision surgery for adjacent segment changes after lumbosacral fusion. Inclusion criteria were as follows: 1) minimum 24 months follow-up, 2) confirmed adjacent segment changes by CT-myelogram or MRI, 3) conservative treatment for at least 3months, 4) available preoperative X-ray films and 5) posterolateral fusions at a prior fusion. Correlation analysis was performed for age, sex, the number of fused levels, grade of radiographic degeneration and instrumentation using the independent sample t-Test. RESULTS: Age, sex, the number of fused levels, the use of instrumentation and the preservation of lumbar lordosis were not correlated with the interval to revision (IR). However, the grade of radiographic degeneration (plain film and CT) were highly correlated with IR (R= -0.699, -0.654). Degenerative scoliosis had a shorter IR, with statistical significance (P<0.05), than other disease examined. Excellent and good clinical results were obtained in 14 patients (60%), and solid bony fusion was achieved in 18 patients (90%). CONCLUSIONS: When deciding upon fusion level, especially in cases of degenerative scoliosis, the need for caution could not be overemphasized. The grade of radiographic degeneration provides a useful indicator for predicting earlier adjacent segment changes.

Internal Fixation for the Lumbosacral Fusion Using Long Bone Plate and Screw / 대한정형외과학회잡지

The lumbosacral fusion has some problems because of it's biomechanical characteristics especially in the unstable spine of various causes and results considerable cases of pseudoarthrosis even with long immobilization. The conventional internal fixators for the spine are not adequate for the lumbosacral fixation with difficulty of sacral fixation maintaining lumbosacral lordosis and risk of the sacral nerves. Recently the pedicle screws and sacral screws connected to the plates or rods are known to be very effective and safe for the lumbosacral fixation permiting early mobilization and decreasing the incidence of pseudoarthrosis. Authors reviewed 10 cases of lumbosacral fusion with internal fixation using the long bone plates and screws which were managed since June 1986 at the department of orthopaedic surgery, Daegu Fatima Hospital and the followings were obtained. 1. The cases were 5 isthmic and 5 degenerative spondylolisthesis with enough spinal stenosis and instability before surgery or after decompression procedures having ages from 39 to 62 years old. 2. All cases had adequate decompression and bilateral intertransverse fusion combined with the internal fixation from 4th lumbar spine to sacrum. 3. Post-operative complications noted in 3 cases such as superficial infection, marginal skin necrosis, paralytic ileus, urinary difficulty and loosening of screws which were all improved without additional procedures. 4. There was no pseudoarthrosis at follow-up examination of 6 months to 1 year and 9 months in spite of a case of loosening of screws. 5. Ambulation was allowed in 2 weeks after surgery wearing lumbosacral corset and all satisfied the results having complete or significant improvement of the symptoms. 6. The internal fixation using long bone plates and screws for the lumbosacral fusion was considered to be effective with very low cost and good mobility.