Effect of posterior osteotomy on the sagittal parameters of the spinopelvis in patients with lumbar degenerative kyphosis / 中国骨伤

OBJECTIVE@#To investigate the influence of posterior osteotomy on spinopelvic parameters in lumbar degenerative kyphosis (LDK) patients.@*METHODS@#The clinical data of 21 patients with lumbar degenerative kyphosis who underwent osteotomy from January 2012 to December 2015 were retrospectively analyzed. There were 5 males and 16 females, aged from 55 to 76 years with an average of (66.24±5.13) years. All patients had taken preoperative and postoperative full length spinal X-ray, analyzing the spinopelvic parameters as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS).@*RESULTS@#All operations were successful, the average operative time was 190 min (160 to 220 min) and intraoperative blood loss was 1 000 ml (800 to 1900 ml). Parameters of the patients between preoperative and period 1-year follow-up were as follows : preoperative TK increased from (31.67±21.13) ° to (34.67±11.60) °, LL corrected from (4.76±3.17) ° to (37.41±6.28) °, PT reduced from (33.94±5.01) ° to (20.12±5.36) °, and SS improved from (18.47±2.60) ° to (31.71±4.30) °, SVA restored from (13.24±3.60) cm to (2.82±1.33) cm. There were significant differences of spinopelvic parameters between preoperation and postoperation (<0.05).@*CONCLUSION@#Posterior osteotomy can effectively reconstruct the sagittal balance of spinopelvis in patients with lumbar degenerative kyphosis. The recovery of lumbar lordosis and sacral slope is closely related to the reconstruction of sagittal balance.

The functional status of the paraspinal muscles among patients with degenerative lumbar kyphosis before and after surgery / 中华物理医学与康复杂志

Objective To study any changes in the surface electromyography of the paraspinal muscles before and after surgery in patients with degenerative lumbar kyphosis.Methods Thirty patients with lumbar degenerative kyphosis (LDK) were enrolled and underwent pedicle subtraction osteotomy.Surface electromyograms were recorded before the operation and 3 months afterward to observe the myoelectric activity of the paraspinal muscles.The electromyograms were also compared with those of healthy counterparts.Results The preoperative average EMG (AEMG) values in the LDK group in static standing were significantly higher than those of the control group.After the operation the values had decreased significantly,but were still significantly higher than in the control group.The preoperative AEMG values of the LDK group from the L1-2 segment during torso stretching were significantly lower than those of the control group.They increased significantly after the operation and were no longer significantly different from the control groups' readings.The pre-and post-operative AEMG values from the L4-5 segment were not significantly different and remained significantly lower than in the control group.During lifting and holding the mean power frequency slopes of the LDK group were significantly lower than those of the controls both before and after the operation,though the postoperative slopes were significantly higher than the preoperative ones.Conclusion Patients with lumbar degenerative kyphosis have obvious paraspinal muscle weakness and severe fatigue.Early pedicle subtraction osteotomy can significantly improve the functional status of the paravertebral muscles in the short term.

Natural History of Lumbar Degenerative Kyphosis with Conservative Treatment

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate the natural history of conservatively treated lumbar degenerative kyphosis (LDK). SUMMARY OF LITERATURE REVIEW: The correlations between the clinical and radiologic parameters of general adult spinal deformity (ASD) are widely known. However, in LDK, dynamic sagittal imbalance is present during ambulation, meaning that its pathogenesis and natural history are different and not widely recognized compared to those of other forms of ASD, resulting in many controversies regarding treatment. To elucidate the natural history of LDK, we analyzed the clinical and radiologic outcomes of patients, comparing their first and final follow-up visits, and evaluated correlations among clinical and radiologic parameters. MATERIALS AND METHODS: From June 2006 to January 2014, 31 patients diagnosed with LDK who underwent conservative treatment were studied. The mean age of the patients was 72.5 years, and the mean follow-up period was 59.2 months. Clinical and radiologic evaluations were conducted on the first and final follow-up visits. Clinical evaluations were done using a visual analog scale and the Oswestry disability index, and radiologic evaluations were performed using spinal and pelvic parameters over a follow-up period of at least 24 months. RESULTS: Patients who were diagnosed with LDK and underwent conservative treatment showed no significant differences in their clinical outcomes between the first and final follow-up. Some radiologic parameters significantly progressed. There were no significant differences between clinical and radiologic parameters at the initial and final follow-up visits. CONCLUSIONS: During the follow-up period of patients diagnosed with LDK, some radiologic parameters progressed. However, the progress of LDK and the clinical symptoms reported by the patients did not significantly change. Decisions regarding the treatment of LDK should not be made according to radiologic parameters showing the degree of deformity, but by carefully determining the patients' clinical symptoms and disability level.

Surgical Correction in Patients with Lumbar Degenerative Kyphosis Who Had Low Bone Mineral Density: An Analysis of 40 Patients with a Minimum Follow-Up of Two Years

STUDY DESIGN: Retrospective study. PURPOSE: To investigate influence of bone mineral density (BMD) on the surgical correction of lumbar degenerative kyphosis (LDK). OVERVIEW OF LITERATURE: No studies so far have reported the influence of BMD on the surgical correction of LDK. METHODS: Forty LDK patients with more than 2 years follow-up were studied. Pelvic incidence (PI), pelvic tilt, sacral slope, sagittal vertical axis (SVA), lumbar lordosis (LL), and thoracic kyphosis were measured preoperatively, immediate postoperatively and at final follow-up. Adverse outcomes: proximal adjacent fractures, sagittal decompensation, pseudoarthrosis, and cage subsidence were documented. RESULTS: There were 37 females and 3 males. Average age was 65.1+/-4.5 years and mean follow-up was 34.2+/-16.7 months. 42.5% were Takemitsu type 3 curves, 27.5% type 2, 20.0% type 4 and 10.0% type 1. 37.5% had osteopenia, 40.0% osteoporosis and 22.5% had severe osteoporosis. SVA improved from 237.0+/-96.7 mm preoperatively to 45.3+/-41.8 mm postoperatively (p=0.000). LL improved from 10.5degrees+/-14.7degrees to -40.6degrees+/-10.9degrees postoperatively (p=0.000). At final follow-up SVA deteriorated to 89.8+/-72.2 mm and LL to 34.7degrees+/-15.8degrees (p=0.000). The association between late sagittal decompensation, pseudoarthrosis, or proximal adjacent fractures and osteoporosis was insignificant. The difference between immediate postoperative LL and PI (PIDiff) had a significant association with sagittal decompensation and pseudoarthrosis. CONCLUSIONS: Osteoporosis did not influence the degree of correction, late sagittal decompensation, proximal adjacent fractures, and pseudoarthrosis in LDK. PIDiff had a significant association with sagittal decompensation and pseudoarthrosis.

Factors Affecting Clinical Results after Corrective Osteotomy for Lumbar Degenerative Kyphosis

STUDY DESIGN: This study is a prospective, clinical study for lumbar degenerative kyphosis. PURPOSE: To determine the factors affecting postoperative clinical outcomes in patients who undergo corrective osteotomy for lumbar degenerative kyphosis. OVERVIEW OF LITERATURE: Only a small number of studies have reported clinical results for surgery for lumbar degenerative kyphosis. There are almost no studies about prognostic factors that predict postoperative clinical results. METHODS: This study involved 25 patients who were diagnosed with lumbar degenerative kyphosis and who underwent corrective osteotomy following gait analysis. A pedicle subtraction osteotomy was done at the third lumbar vertebra (L 3). Regarding the fusion level, surgery was done within a range from T10 proximally to S1 distally. Of these, for rigid fixation of a distal part, an iliac screw was used. Pain was evaluated using a 10-point pain scale and a questionnaire about activities. We also evaluated cosmesis and subjective satisfaction using a modified version of the Scoliosis Research Society Outcome-22 (SRS-22) instrument. This assessment was done using a 5-point scale which was designed by us. We assigned patients to group A (good clinical outcomes) if their postoperative pain score was lower than 4 (of 10 points) and if scores indicating activity, cosmesis and subjective satisfaction were higher than 11 (of 15 points). All other patients were assigned to group B (poor clinical outcomes). RESULTS: Clinical outcomes were good in 64% of patients (16/25) and poor in 36% (9/25). Regarding cosmesis and subjective satisfaction, there were significant differences between the two groups. There were also significant differences in physical factors of individual patients such as body mass index (BMI): 23.78 +/- 2.79 in group A and 26.44 +/- 2.75 in group B. On gait analysis, there was a significant difference in the dynamic pelvic tilt: 7.5 +/- 3.3degrees in group A and 11.72 +/- 1.89degrees in group B. CONCLUSIONS: There is no correlation between preoperative degree of kyphotic deformity and clinical outcomes. The degree of anterior rotation of pelvic tilt does not change significantly; rather, compensatory mechanisms of the pelvis and BMI were found to have more influence. Because neither the degree of satisfaction with clinical outcomes nor the increased activity was relatively higher, a more sincere decision should be made before recommending corrective osteotomy for degenerative lumbar kyphosis.

Loss of Sagittal Balance and Clinical Outcomes following Corrective Osteotomy for Lumbar Degenerative Kyphosis / 대한정형외과학회잡지

PURPOSE: To report the loss of correction of a sagittal imbalance and the clinical outcomes after a corrective osteotomy for lumbar degenerative kyphosis. MATERIALS AND METHODS: This study analyzed the radiological parameters, surgical techniques, and clinical outcomes of 23 patients, who underwent corrective osteotomy for lumbar degenerative kyphosis. The patients were divided into groups I (>5 cm loss of correction of sagittal imblance, 12 patients) and II (3.5 out of 5, 11 patients) was compared with group B (low satisfaction score group <3.5 out of 5, 12 patients). RESULTS: The sagittal imbalance was corrected by performing a Smith-Petersen osteotomy (SPO) in 11 cases and Pedicle subtraction osteotomy (PSO) in 12. The mean preoperative sagittal imbalance was improved from 26.4 cm to 4.05 cm, postoperatively, and 11.2 cm at the last follow up. The mean loss of correction was 11.2 cm in group I and 2.3 cm in group II. The mean satisfaction score was 4.56 in group A and 2.18 in group B. The presence of an old compression fracture was found to be related to the loss of correction, and the preoperative symptomatic spinal stenosis was related to poor clinical outcomes. CONCLUSION: After mean 45 month follow up, the mean loss of sagittal correction was 38.3%, which mainly occurred at the proximal unfused segment. The clinical success rate was 45.5%, regardless of the loss of sagittal balance correction.

Radiologic Analysis of Postoperative Sagittal Plane Correction in Lumbar Degenerative Kyphosis (LDK) / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study OBJECTIVES: We radiologically analyzed the correction of the sagittal imbalance and the proximal fusion level to prevent correction loss and the usefulness of iliac screws in LDK. SUMMARY OF THE LITERATURE REVIEW: Complications can be encountered during fixation and fusion as most of the LDK patients are aged, and the osteoporosis that causes fixation loss is known to affect the loss of correction. MATERIALS AND METHODS: We analyzed the cause of correction loss among 35 patients who underwent surgery and who were followed up for at least 1 year. All the patients had performed gait analysis before operation. The operative techniques were pedicle subtraction osteotomy and fixation to S1. For analyzing causes of correction loss, we analyzed the degrees of lumbar lordosis for the sagittal correction and the degrees of the preoperative thoracolumbar kyphosis for the proximal fusion range. For analyzing the usefulness of iliac screws, the subjects were divided into two groups: 1) the -iliac screw (23cases) group for the patients who were fixed without iliac screws and 2) the +iliac screw (12cases) group for the patients who were fixed with iliac screws. RESULTS: There were no patients who had marked anterior pelvic tilt. It is important to correct the lumbar lordosis over 20degrees compared with the preoperative thoracic kyphosis. There are 10 cases of preoperative thoracolumbar kyphosis > or = 10degrees and 25 cases of preoperative thoracolumbar kyphosis or = 10degrees, 4 cases that were fixed to T10 had no sagittal correction loss, and 2 of the 6 cases that were fixed to T11 or T12 had sagittal correction loss. For the 25 cases of preoperative thoracolumbar kyphosis < 10degrees, 5 cases that were fixed to T10 had no sagittal correction loss and 1 of the 20 cases that were fixed to T11 or T12 had sagittal correction loss (p<0.05). 6 cases (26%) in the -iliac screw group (23 cases total) and 1 case (8%) in the +iliac screw (12 cases total) showed sagittal correction loss (p<0.05). CONCLUSIONS: It is important to make the postoperative lumbar lordosis over 20degrees compared with the preoperative thoracic kyphosis for correcting sagittal imbalance, to decide on the proximal fixation level according to the preoperative thoracolumbar kyphosis and to fix with iliac screws.

Change of Pelvic Tilt before and after Gait in Patients with Lumbar Degenerative Kyphosis / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study. OBJECTIVES: We wanted to verify the value of radiography and gait analysis to analyze the changes of the pelvic tilt before and after gait in the patients with LDK. Summary of Literature Review: Patients with lumbar degenerative kyphosis show dynamic changes that are closely associated with the motion of pelvis. MATERIALS AND METHODS: We analyzed 18 lumbar degenerative kyphosis patients who didn't have multiple vertebral compressio fractures, a past history of spinal surgery or surgery for degenerative arthritis of the knee or hip, and obesity which causes marker errors on the gait analysis. Pelvic tilt was statistically evaluated by utilizing radiographs and dynamically utilizing the gait analysis. The linear parameters of the gait cycle and the kinematic data were obtained from the gait analysis. RESULTS: The LDK patients'mean walking velocity was 80.7 cm/s, and it was largely decreased to 65% of the normal value. The cause of the decreased walking velocity was a decrease of stride length, and not a decrease of cadence. The mean static pelvic tilt in the gait analysis was -1.3+/-8.0degrees , and there were 8 cases of anterior tilt and 10 cases of posterior tilt. The mean pelvic tilt during gait was 12.5+/-8.2degrees , and there were 17 cases of anterior tilt and 1 case of posterior tilt. It was statistically significant difference (p<0.05) between the mean static pelvic tilt in gait analysis and the mean pelvic tilt during gait and the Pearson's correlation coefficient was -0.88. CONCLUSIONS: Though there was no statistical significance, we observed anterior pelvic rotation after gait on the radiographs. As fatigue of the pelvic extensor muscles increases during gait, anterior pelvis tilt increases with statistical significance on the gait analysis. Therefore, we feel gait analysis is useful for evaluating the dynamic change of the pelvic tilt in patients with LDK.

Dynamic Changes of Pelvis and Lower Extremities after Operation in Lumbar Degenerative Kyphosis

OBJECTIVE: Gait pattern in patients with lumbar degenerative kyphosis (LDK) is disturbed because trunk bends forward due to decreased lumbar lordosis. Surgical therapy in LDK is required when conservative management fails. We investigated kinematic and kinetic changes of the pelvis, hip, and knee joints on the sagittal plane in patients with LDK before and after operation. METHOD: Fifteen patients underwent operations between March 1999 and September 2003. Gait analysis was performed for all patients. RESULTS: Total lumbar lordotic angle increased from 10.50 degrees +/-11.22 degrees to 26.71 degrees +/-8.80 degrees postoperation. In gait analysis, anterior pelvic tilting angle increased from maximum 7.86 degrees +/-9.69 degrees, minimum 4.40 degrees +/-9.82 degrees to maximum 12.61 degrees +/-5.36 degrees, minimum 9.68 degrees +/-5.63 degrees (p<0.05). Maximum hip flexion angle changed from 31.39 degrees +/-11.71 degrees to 35.83 degrees +/-5.84 degrees (p<0.05). Maximum knee flexion angle in terminal stance phase decreased from 13.32 degrees +/-7.34 degrees to 8.30 degrees +/-6.38 degrees (p<0.05). CONCLUSION: After corrective operation, an increase of lumbar spine lordosis and anterior pelvic tilt with decrease of knee flexion were observed. However, an increase of maximum hip flexion secondary to increased anterior pelvic tilting influenced ambulation negatively. Therefore, stretching of the hip flexor and strengthening of the hip extensor are required before and after operation.

Anterior and Posterior Surgical Treatment with Wedged Cage (SynCage(R)) in Lumbar Degenerative Kyphosis / 대한척추외과학회지

STUDY DESIGN: Prospective study. OBJECTIVES: Analyzing the clinical outcome of operative treatment in lumbar degenerative kyphosis (LDK) by means of anterior and posterior operation using Wedged cage (SynCage(R)) and pedicle screws. SUMMARY OF LITERATURE REVIEW : LDK is common in old farmers who have worked in a stooping posture for decades and is a quite rigid form of kyphosis accompanied by adjacent instability, dystrophic changes of vertebral bodies and weakness of back and hip extensors. For surgical treatment, restoration and maintenance of lumbar lordosis is mandatory for global balance. Anterior release and restoration of disc space with the same morphologic cage seems to be a quite anatomic and harmonious approach. MATERIALS AND METHODS: Ten LDK patients, who underwent anterior interbody fusion using Wedged cage (SynCage(R)) and posterior fusion with pedicle screws between 2000 to 2001, were followed up for more than 2 years. The operation was done in one or two stages. We performed anterior release, gradual widening of the intervertebral space with wedge trials of increasing size, insertion of wedged cages filled with auto-, allo- or synthetic bone and posterior pedicle fixation and fusion. We measured the lumbar lordotic angle, sacral inclination, fusion segmental angle, thoracic kyphotic angle and vertical axis line in preoperative, immediate postoperative and follow-up standing X-ray. RESULTS: Mean fusion segments using Wedged cage were 2.8 segments for anterior interbody fusion and 3.4 segments for posterior fusion. Mean sagittal correction angle was 40.3 degrees with mean correction loss of 2.6 degrees. Whole lordosis was 6.9 degrees kyphosis preoperatively, which was corrected to 33.4 degrees lordosis postoperatively and 30.8 degrees lordosis at last follow-up. Mean sacral inclination was corrected from 18.2 degrees preoperatively to 37.8 degrees postoperatively and 30.7 degrees at follow-up. Vertical axis line was corrected from 11.4 cm preoperatively to 0.4 cm postoperatively and 1.3cm at follow-up. Thoracic lordosis was corrected spontaneously without any surgical extension to the thoracic spine by mean 19.9 degrees(0.2 degrees lordosis preoperatively to 19.7 degrees kyphosis at follow-up). Loss of cardinal signs occurred in 70-80 % of patients and satisfactory clinical results were shown in 90% of patients. CONCLUSIONS: Anterior and posterior fusion using Wedged cage (SynCage(R)) and pedicle screws showed high efficiency in the correction and maintenance of LDK. It is a good modality in the surgical treatment of lumbar degenerative kyphosis.

A Clinical Analysis of Surgical Treatment of Lumbar Degenerative Kyphosis / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To analyse associated preoperative conditions and postoperative causes of sagittal imbalance and to analyze clinical results of surgical treatment of lumbar degenerative kyphosis. SUMMARY OF LITERATURE REVIEW: There have been many controversies and high possibility of unsatisfactory results in surgical treatment of symptomatic degenerative lumbar kyphosis, which was complicated condition usually needed multi-level operation in old age. MATERIALS AND METHODS: We analyzed 24 patients who complained of long standing stooping as one of main symptoms with radiologically measured lumbar kyphosis and underwent surgical restoration of lumbar lordodsis with long segmental spinal fusion from 1995 to 1999. Mean follow-up was 31.9months(from 24 to 48 months). Operative treatments were posterolateral fusion with pedicular screw(15 cases), anterior and posterior interbody fusion(5 cases), posterior interbody fusion with cage(1 case) and decancellation osteotomy(3 cases). Cases divided into 2 groups(Group A: improved stooping, Group B: recurred stooping) were evaluated by radiological measurement of changes in surgically restored lumbar lordosis correlated with clinical improvement of stooping. Overall clinical results were evaluated according to Kirkaldy-Willis criteria. RESULTS: The associated conditions of preoperative lumbar kyphosis were recognized as multiple disc degeneration, segmental instability, degenerative vertebral wedging and pseudospondylolisthesis. Post-operative stooping recurred in 5 cases and caused by adjacent kyphosis in 2 cases, loss of correction in 1 case and both in 2 cases. Loss of correction was associated with pseudarthrosis in 1 case, screw loosening in 3 cases and allograft collapse in 2 cases. According to Kirkaldy-Willis, 8 cases of unsatisfactory clinical results consisted of 3 cases of pseudarthrosis out of 19 cases of Gruop A and all cases(5 cases) in group B. Most of correction loss occurred at lower lumbar spine(L3-S1) and was closely related to post-operative sagittal imbalance. CONCLUSIONS: Maintenance of well corrected lumbar lordosis for sagittal balance and prevention of pseudarthrosis were mandatory for good clinical outcome in surgical treatment of lumbar degenerative kyphosis.

Significance of Gait Analysis in Surgical Treatment of Lumbar Degenerative Kyphosis

OBJECTIVE: Sagittal imbalance in lumbar degenerative kyphosis (LDK) is usually more evident when walking, suggesting its dynamic nature. Radiographic examination which only revealed the static status of the spine was considered to be inadequate for assessment of this condition. Gait analysis allows estimation of dynamic spinal imbalance associated with the pelvis and lower extremities in LDK. This study was designed to predict the success of surgery for LDK with gait analysis. METHOD: Twenty-six patients who had corrective surgery after gait analysis and had been followed up for more than two years were included in this study. All patients were female, and in average 57.1 years of age (42-70). Group I consisted of 21 satisfactory patients with marked improvement in stooping, and Group II consisted of five patients with persistent stooping, whose condition remained unsatisfactory despite surgery. In order to find the cause of postoperative persistent stooping, various radiographic and preoperative gait parameters were compared between the two groups. RESULTS: The average angle of anterior pelvic tilt, hip, and knee flexion were more increased in Group II than Group I. The pattern of hip internal moment in stance phase of gait cycle was biphasic in Group I, similar to the normal pattern, whereas it was monophasic and internal hip extensor hip moment was increased throughout the stance phase in Group II. CONCLUSION: An available tool that permitts practical evaluation of dynamic sagittal imbalance of the spine is gait analysis as substantiated by the results of this study.