Correction Of Lumbar Lordosis Research Articles

Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis

There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4-8) in the L5 group and 6.09 (range 4-9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7 degrees before surgery to 6.8 degrees after surgery in the L5 group, and from 22.8 degrees to 7.7 degrees in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at L5-S1 and loosening of L5 screws. Seven of the nine patients showed preoperative sagittal imbalance and/or lumbar hypolordosis, which might be risk factors of complications at L5-S1. For the patients with sagittal imbalance and lumbar hypolordosis, L5-S1 should be included in the fusion even if L5-S1 disc was minimal degeneration.

Short fusion versus long fusion for degenerative lumbar scoliosis

The extent of fusion for degenerative lumbar scoliosis has not yet been determined. The purpose of this study was to compare the results of short fusion versus long fusion for degenerative lumbar scoliosis. Fifty patients (mean age 65.5 +/- 5.1 years) undergoing decompression and fusion with pedicle screw instrumentation were evaluated. Short fusion was defined as fusion within the deformity, not exceeding the end vertebra. Long fusion was defined as fusion extended above the upper end vertebra. The lower end vertebra was included in the fusion in all the patients. The short fusion group included 28 patients and the long fusion group included 22 patients. Patients' age and number of medical co-morbidities were similar in both the groups. The number of levels fused was 3.1 +/- 0.9 segments in the short fusion group and 6.5 +/- 1.5 in the long fusion group. Before surgery, the average Cobb angle was 16.3 degrees (range 11-28 degrees ) in the short fusion group and 21.7 degrees (range 12-33 degrees ) in the long fusion group. The correction of the Cobb angle averaged 39% in the short fusion group and 72% in the long fusion group with a statistical difference (P = 0.001). Coronal imbalance improved significantly in the long fusion group more than in the short fusion group (P = 0.03). The correction of lateral listhesis was better in the long fusion group (P = 0.02). However, there was no difference in the correction of lumbar lordosis and sagittal imbalance between the two groups. Ten of the 50 patients had additional posterolateral lumbar interbody fusion at L4-5 or L5-S1. The interbody fusion had a positive influence in improving lumbar lordosis, but was ineffective at restoring sagittal imbalance. Early perioperative complications were likely to develop in the long fusion group. Late complications included adjacent segment disease, loosening of screws, and pseudarthrosis. Adjacent segment disease developed in ten patients in the short fusion group, and in five patients in the long fusion group. In the short fusion group, adjacent segment disease occurred proximally in all of the ten patients. Loosening of distal screws developed in three patients, and pseudarthrosis at L5-S1 in one patient in the long fusion group. Reoperation was performed in four patients in the long fusion group and three patients in the short fusion group. In conclusion, short fusion is sufficient for patients with small Cobb angle and good spinal balance. For patients with severe Cobb angle and rotatory subluxation, long fusion should be carried out to minimize adjacent segment disease. For patients who have severe sagittal imbalance, spinal osteotomy is an alternative technique to be considered. As long fusion is likely to increase early perioperative complications, great care should be taken for high-risk patients to avoid complications.

Lumbar Spinal Osteotomy for Kyphosis in Ankylosing Spondylitis

Retrospective analysis of 11 consecutive patients with ankylosing spondylitis who underwent lumbar spinal osteotomy for severe kyphosis, with a mean follow up of 4 (2 to 8.5) years. The chin brow vertical angle, thigh flexion angle, and the whole body kyphosis angle (WBKA) were measured on the clinical photographs of the patient in standing. The lumbar lordosis, thoracic kyphosis, total kyphosis, sacral slope, and sagittal balance were measured on the standing radiographs. A closing wedge osteotomy at L3 was done in all patients. Intraoperative neuromonitor with sensory evoked potentials and motor evoked potentials was used routinely. Stable fixation of spine allowed early walking. There were no permanent neurologic complications. The average preoperative WBKA was 41 degrees (20 to 70 degrees). The average correction of lumbar lordosis was 40 degrees, from 21.4 degrees (-10 to 65 degrees) to 61.4 degrees (35 to 85 degrees). The thigh flexion angle improved from 9.7 degrees (4 to 20 degrees) to 0.4 degrees (-4 to 5 degrees), the sacral slope from 11.8 degrees (-5 to 35 degrees) to 31.8 degrees (20 to 45 degrees), and the chin brow vertical angle from 28.2 degrees (10 to 45 degrees) to 2.4 degrees (-5 to 18 degrees). Loss of correction of 5 and 10 degrees was seen in 2 patients. The ability to stand upright and look straight was restored in all patients. The WBKA correlated closely with the amount of lordosis correction in lumbar spine. The intraobserver and interobserver reproducibility of the WBKA was verified by statistical analysis. In our opinion the measurement of the WBKA on the preoperative photograph is helpful in planning the lumbar osteotomy.

Sagittal Translation in Opening Wedge Osteotomy for the Correction of Thoracolumbar Kyphotic Deformity in Ankylosing Spondylitis

Retrospective. To document sagittal translation (ST) of the vertebral column in opening wedge osteotomy (OWO) for ankylosing spondylitis (AS) kyphosis. Surgeons recognize displacement at the hinge of correction in OWO as an accidental event between the vertebrae on the side of OWO rather than ST of the cranial or caudal vertebral column. No report documents ST in this context. We evaluated radiographic and clinical results in 127 patients (aged 17-49 years) for ST, or displacement of more than 2 mm between the cranial and caudal vertebral columns at the OWO level, over 5 years. Thirty-four (27%) patients had ST. In 31 (94%), the kyphotic apex was at T11 to L4. ST was positively correlated with the correction of lumbar lordosis and preoperative lumbar kyphosis. Five (15%) of 34 patients with ST had neurologic complications compared with 2 (2%) of 93 who did not. ST is a basic mechanism for correcting sagittal imbalance and is likely to occur when the level of OWO is near the apex of deformity. Patients needing more correction of lumbar lordosis than others for best correction of sagittal imbalance need ST more to join the mechanism of correction.

Ostéotomie de soustraction pédiculaire dans le traitement des déséquilibres antérieurs du rachis: À propos de 34 cas

Purpose of the study The aim of this study was to analyze x-ray results in patients who underwent pedicle subtraction osteotomy for complex deformations (flat back, kyphosis) leading to fixed sagittal imbalance. Material and methods Thirty-four patients underwent surgery between 1996 and March 2003 in two centers, the orthopedic surgery unit devoted to spinal surgery and sports traumatology at the Strasbourg University Hospitals and the spinal surgery unit at the Chenove Clinic (Dijon). The series included 20 women and 14 men, mean age 46.5 years (range 14-74 years) treated for: postoperative flat back (n = 19), kyphoscoliosis (n = 6), ankylosing spondylarthritis (n = 5), and malunion (n = 4). After careful planning to achieve the necessary degree of correction, the patient was installed on a Cotrel table with a stable support enabling limited blood loss and facilitated reduction maneuvers via elevation of the lower limbs. The technique started by resection of the posterior arch, the transverse processes, and the pedicles, followed by partial resection of the body with a chisel under fluoroscopic control. The closure was achieved by in situ reduction with compressive rotation. Adjacent discs were then evaluated to search for any opening which could be filled by an anterior graft to complete the stabilization. The osteosynthesis used 2-, 4-, and 6-rod assemblies. The 6-rod assemblies enabled anchoring the fixation above and below before the osteo-tomy. Two prebent rods completed the assembly at reduction after osteotomy. Weight-bearing started on day 4. A protective corset was worn for three months by 19 patients. The patients resumed their occupational activities on average 6.73 months postoperatively without change in activity for 63%. Overall satisfaction was close to 90% excellent outcome. Results All clinical results were analyzed with the Profil software of Surgiview. X-ray data were analyzed with Spineview. A self-administered clinical questionnaire was used to evaluate pain, result of the operation, and the impact on the patient's body image. On average, the wedge osteotomy measured 28.9° for correction of lumbar lordosis by 31.5̊ with a maximum of 65̊. The misalignment at C7 was reduced from 51 mm to 2 mm. At the pelvic level, version improved 16̊, sacral slope 8̊. There were four dura mater breaches which had to be sutured, but with no clinical consequence (one progression to meningocele). Mean intraoperative blood loss was 1400 cc (300-4500cc) for a mean operative time of 260 minutes (165-450 min). There were two early infections at day 15 postop which resolved with antibiotics. Four patients developed resolutive sciatica (n = 2) or cruralgia (n = 2) during the following months. The short-term follow-up revealed eight non-unions (25%) with rupture of osteosynthesis material and loss of correction. The opening in the adjacent discs and the insufficient posterior closure explained this mechanical complication. Conclusion Pedicle subtraction osteotomy is an original operative technique reserved for specialized centers. A well-experienced team is needed to control the risks involved. Sagittal balance should be one of the important goals for modern spinal surgery.

Ostéotomie de fermeture postérieure par impaction intracorporéale pour dos plat postopératoire: À propos d’une série de 22 cas

Purpose of the study There is increasing interest in sagittal balance as an important element when planning treatment of spinal deformations. Posture disorders, particularly flatback, can be observed after surgical treatment of scoliosis. The frequency of flat back syndrome has increased with the development of spinal surgery. Material and methods Posterior osteotomy is designed to resolve these problems. Two techniques are used: the Smith-Petersen procedure and transpedicular subtraction osteotomy. We adopted the second procedure, adding two technical modifications: installation on an orthopaedic table and intracorporeal cancellous impaction. We performed closed posterior osteotomy by intracorporeal impaction and report here our results in a series of 22 patients with postoperative flat back treated between July 1999 and June 2002. Mean age at surgery was 52 years. There were sixteen women and six men. All patients had a history of spinal surgery with fusion. They had had 2.1 spinal operations on average with a maximum of seven. All patients complained of severe postural pain. They had difficulty bending forward and standing back up. Radiographically, we noted altered spinal and pelvic angles and an abnormal plumb line from C7 to the promontory. Results We analyzed outcome at 21 months on average. Preoperatively five patients had 12 levels of non-union. Osteotomy was performed at L4 in nineteen patients and L3 in three. A rigid instrumentation was used in all cases. Osteosynthesis material was implanted after correction of the deformation with no particular problem for spinal stability or reduction. Mean operative time was 180 minutes and mean blood loss was 1680 ml. A complementary anterior approach was required in one patient. Intraoperative complications were dominated by dural breaches in five patients, high paraplegia not directly related to the osteotomy in one patient, regressive S1 paresia occurred in one patient and transient cruralgia which regressed in 4 to 6 months in four patients. We also observed functional intestinal obstruction in one patient and severe depression in another. There were no infections or deaths. We also observed two cases of predominant correction at the discal level and not the vertebral level. All operated patients felt their posture was improved and were able to maintain the upright position for prolonged periods. Flexion of the lower limbs was improved. Mean correction of lumbar lordosis was 25.1° (range 12-39). Mean sacral slope was 33°. Mean correction of the position of C7 on the promontory plumb line was 72 mm. This variable was highly altered preoperatively (95.6 mm) and was improved after osteotomy in all patients. At last follow-up, there was one case of nonunion which had been successfully revised. Discussion The literature on osteotomy for the treatment of flat back is sparse. Our series of subtraction osteotomy is the largest reported to date. Preoperative and intraoperative planning remain a topic of debate and require further study.

THE BASIC ANATOMY OF SCOLIOSIS

1. Evidence is presented that the basic lesion in scoliosis is relative lengthening of the anterior components of the spine compared with the posterior elements. 2. The logical treatment is to reduce this relative lengthening either by lengthening the posterior elements or shortening the anterior elements. This may be achieved by anterior lumbar wedge osteotomy or by epiphysiodesis; and correction of lumbar lordosis can improve a thoracic scoliosis.