Lumbar Alignment Research Articles

The Correlation Between Pelvic Obliquity And Dynamic Alignment Of Knee During Gait.

Tsuji et al. reported that a patellofemoral joint pain was related to a sacral inclination that caused by changing of lumbar alignment, and they called this pathological concept “the knee-spine syndrome”. Tauchi et al. reported that influence of spinal imbalance on knee osteoarthritis. However, few studies reported the dynamic alignment on the frontal plane on the frontal plane to elucidate knee - spine syndrome. PURPOSE: To investigate association of the dynamic alignment of the pelvic and the knee during gait. METHODS: This study included 100 patients (58 male; 31.7±17.45ys, 168.0±6.74cm, 63.1±11.33kg and 42 female; 38.5±20.42ys, 156.5±8.71cm, 52.0±10.93kg) with pain in the lower limbs and/or low back pain. The dynamic alignment of pelvic and knee during gait was measured at our clinic using a motion analysis system which consisted of six cameras, two force plates, and 39 retro-reflective markers. The relationship between the frontal plane motion of pelvic (i.e. pelvic obliquity) and knee (i.e. knee varus-valgus) were analyzed using linear regression. Then the patients were classified into three groups by pelvic obliquity imbalance and the dynamic alignment of knee was compared among four groups. RESULTS: At the initial contact of left foot, the pelvic right obliquity angle was 3.7±1.92 (degrees; d) and the angular velocity of left knee varus was 28.3±38.26 (degree/sec; d/s), and the coefficients of correlation of them (r) was -.091 (ns). On the other hand at the initial contact of right foot, the pelvic left obliquity angle was 5.8±2.15 (d) and the angular velocity of right knee varus was 37.9±34.43 (d/s), and r was .379 (p> right obliquity) group was 40.7±7.63 (d/s), and was larger than normal balance group (24.4±4.29 (d/s), p<.05 ). CONCLUSIONS: In the landing movement, the correlation between the dynamic alignment of trunk and knee was reported. The same as the previous study, this study suggested that the correlation between pelvic obliquity and knee varus during gait. We hypothesize that the increases in pelvic obliquity motion from initial contact to foot flat was increased of frontal-plane knee movement and torques because of to transfer lateral-down forces from the trunk through the lower extremity. The findings of this study will provide clinicians with useful information for prevention overuse injuries.

Radiological Assessment of Bilateral Decompression through Unilateral Approach for the Treatment of Lumbar Spinal Canal Stenosis

Introduction Various surgical techniques have been introduced to establish less invasive procedure for the treatment of lumbar spinal canal stenosis (LSCS). Bilateral decompression through a unilateral approach (BDUA) is one of those techniques. This retrospective study was designed to evaluate radiological changes of lumbar spinal alignment after BDUA and to compare with those of conventional fenestration. Material and Methods A consecutive 73 patients (53 males, 20 females; mean age, 71yrs.) underwent BDUA from 2004 to 2012 were included in this study and conventional fenestration (CF) group consisted of 25 patients (12 males, 13 females; mean age, 72yrs.) treated from 2000 to 2012 at the same hospital. Mean number of decompressed level were 2.5 in BDUA and 2.0 in CF. To investigate radiological change of lumbar spine, following parameters were measured on X-rays of pre-op, one year (1Y), and two year (2Y) after surgery: Disc angle and ROM of L4–5, Lumbar lordosis (LL, sagittal angle of L1–5), coronal alignment of L4–5, and L1–5. Clinical results were assessed by Japananese Orthopaedic Association Scoring System (JOAS). Results Preoperative disc angle of L4–5 was 7.4 degrees in BDUA and 7.3 degrees in CF and changed to 8.1 degrees, 8.3 degrees at 1Y, 7.6 degrees, 8.8 degrees at 2Y, respectively. A comparison between two groups showed no significant difference at each point. ROM of L4–5 in both group also showed no significant difference at each point; pre-op: 7.3 degrees, 6.9 degrees, 1Y: 6.1 degrees, 6.0 degrees, 2Y: 7.0 degrees, 5.7 degrees. Preoperative LL was 18.7 degrees in BDUA and 21.8 degrees in CF and changed to 19.5 degrees, 23.7 degrees at 1Y, 19.5 degrees, 23.5 degrees at 2Y, respectively. There was no significant difference between two groups at each point. In the coronal plane, L4–5 wedging angle varied from 0 degrees to 7 degrees in BDUA and from 0 degrees to 4 degrees in CF preoperatively. The amount of L4–5 wedging change in two years was 1.4 degrees in BDUA and 1.1 degrees in CF, showing no significant difference. There was no peculiar tendency in coronal change of L4–5 or L1–5 lumbar alignment depending on approach side. JOAS improved significantly after surgery in both group (Recovery rate: 62.5% in BDUA, 56.5% in CF) and was well maintained at 2Y. A comparison of JOAS revealed no significant difference in two groups preoperatively and 2Y; pre-op: 12.7, 2Y: 23.7 in BDUA, pre-op:11.9, 2Y: 21.5 in CF. Conclusions Decompression through unilateral approach has been widely accepted for the treatment of LSCS. This method spares dissection of paraspinal muscle of contralateral side and has an advantage of preservation of contralateral facet joints. On the other hand, especially in multiple decompression, the influence to the muscle balance or to alignment change remains concerns. Current study showed favorable clinical results in both group. There was no particular tendency of alignment change in the coronal plane. These changes seemed to be mainly based on the degeneration process of lumbar spine.

Differences between clinical “snap-shot” and “real-life” assessments of lumbar spine alignment and motion – What is the “real” lumbar lordosis of a human being?

The individual lumbar lordosis and lumbar motion have been identified to play an important role in pathogenesis of low back pain and are essential references for preoperative planning and postoperative evaluation. The clinical “gold-standard” for measuring lumbar lordosis and its motion are radiological “snap-shots” taken while standing and during upper-body flexion and extension. The extent to which these clinically assessed values characterise lumbar alignment and its motion in daily life merits discussion.A non-invasive measurement-system was employed to measure lumbar lordosis and lumbar motion in 208 volunteers (age: 20–74yrs; ♀/♂: 115/93). For an initial short-term measurement, comparable with the clinical “snap-shot”, lumbar lordosis and its motion were assessed while standing and during flexion and extension. Subsequently, volunteers were released to their daily lives while wearing the device, and measurements were performed during the following 24h.The average lumbar lordosis during 24h (8.0°) differed significantly from the standardised measurement while standing (33.3°). Ranges of motion were significantly different throughout the day compared to standing measurements. The influence of the factors age and gender on lordosis and its motion resulted in conflicting results between long- and short-term-measurements.In conclusion, results of short-term examinations differ considerably from the average values during real-life. These findings might be important for surgical planning and increase the awareness of the biomechanical challenges that spinal structures and implants face in real-life. Furthermore, long-term assessments of spinal alignment and motion during daily life can provide valid data on spinal function and can reveal the importance of influential factors.

An imaging study on effect of total artificial disc replacement on lumbar sagittal alignment

To investigate effect of Activ L total lumbar disc replacement on lumbar sagittal alignment. The imaging data of patients with degenerative disc disease received Activ L total lumbar disc replacement at Department of Orthopedics, Beijing Chao-Yang Hospital, Capital Medical University from March 2009 to March 2013 were retrospectively analyzed. The average age was 45.6 years(range, 35-60 years)and the surgery levels were as follows: L3-4 2 cases, L4-5 15 cases, L5/S1 5 cases, L3-4+ L4-5 3 cases, L4-5+ L5/S1 7 cases. All patients were followed up for 15 to 63 months(average, 32 months). Radiographic parameters such as lumbar lordosis angle(LL), segment lordosis angle(SL) and sacral slope angle(SS) were recorded. All the radiographic parameters were compared using one-way ANOVA at different stage. Lumbar lordosis angle of the two-level was compared with the one of one-level by using independent sample t-test before and after the operation. A partial correction test was carried out to determine the corrections between the parameters preoperatively, one month after the operation and at final follow-up. One month after the operation, the lumbar lordosis angle decreased by an average of 1.8°, but there was no statistically significant(P>0.05). Compared with one month postoperation, the lumbar lordosis angle increased by an average of 6.8°(P<0.05), which also increased a lot compared with preoperation(P<0.05). The value of segment lordosis angle was rising up from preoperation to the final follow-up(P<0.05), so was the value of sacral slope angle, but there was no statistically significant between different stage(P>0.05). The lumbar lordosis angle showed no significant difference between double-level ones and single-level ones at different stage(P<0.05). The lumbar lordosis angle showed positive correlation with the sacral slope(P<0.001), however, the lumbar lordosis angle showed no corrected with the segment angle all the time(P>0.05). The total lumbar disc replacement with Activ L prosthesis had contributed to maintain and improve the lumbar alignment in the short and medium term. Double- or single-level total lumbar disc replacement had no significant effect on the value of lumbar lordosis angle. The lumbar lordosis angle showed positive correlation with the sacral slope all the time with no correlation between lumbar lordosis angle and sacral slope.

Biomechanics and Management of Lumbar Spinal Stenosis Neurodegenerative Disease: Mini-Review

Lumbar stenosis is an increasingly common pathology, which causes significant symptoms affecting quality of life, especially in the aging population. The mainstays of treatment employ both conservative and surgical management. Should surgery be required decompression of the lumbar spine via laminectomy or laminotomy has been shown to be effective. The addition of fusion may only benefit in cases with spinal instability. The treatment of lumbar stenosis should include a multifactorial and multidisciplinary approach. Lumbar fusion may lead to an adjacent segment disease as a result of endplate failure by promoting a lumbar alignment with parallel endplates. Upright MRI could be a useful adjunct objective diagnostic option in the future to differentiate symptomatic from asymptomatic patients by evaluating their foraminal geometry.

Current Status of Lumbar Interbody Fusion for Degenerative Spondylolisthesis.

Instrumented lumbar fusion can provide immediate stability and assist in satisfactory arthrodesis in patients who have pain or instability of the lumbar spine. Lumbar adjunctive fusion with decompression is often a good procedure for surgical management of degenerative spondylolisthesis (DS). Among various lumbar fusion techniques, lumbar interbody fusion (LIF) has an advantage in that it maintains favorable lumbar alignment and provides successful fusion with the added effect of indirect decompression. This technique has been widely used and represents an advancement in spinal instrumentation, although the rationale and optimal type of LIF for DS remains controversial. We evaluated the current status and role of LIF in DS treatment, mainly as a means to augment instrumentation. We addressed the basic concept of LIF, its indications, and various types including minimally invasive techniques. It also has acceptable biomechanical features, and offers reconstruction with ideal lumbar alignment. Postsurgical adverse events related to each LIF technique are also addressed.

Calibration method for lumbosacral dimensions in wearable sensor system of lumbar alignment.

Anteflexion of the spine is essential for many physical activities in everyday life. However, this motion places the lumbar disks under heavy load due to changes in the shape of the lumbar spine and can lead to low back pain. With the aim of reducing low back pain, here we developed a wearable sensor system that can estimate lumbosacral alignment and lumbar load by measuring the shape of the lumbar skin when the lumbosacral alignment changes. In addition, we used this system to measure the parameters of anteflexion and studied the change in dimensions of the lumbar spine from changes in posture. By determining the dimensions of the lumbosacral spine on an X-ray image, a lumbosacral dimensions calibration method based on body surface area and height was developed. By using this method, lumbosacral alignment and lumbar load could be accurately estimated using the wearable sensor system.

Do low back pain changes correlate with sagittal lumbar alignment changes after total hip replacement arthroplasty?

Background: The hip joint and lumbar spine are both anatomically and functionally closely related as had shown by many authors. So the abnormality in one area can affect the other e.g. hip joint osteoarthritis can cause lumbar sagittal malalignment and backache.Objectives: is to see if there is significant improvement in backache after total hip replacement? And which degree of backache improvement is associated with significant changes in lumbar lordosis?Methods and patients: a prospective open trial study was performed on 30 patients who had severe hip osteoarthritis and chronic low back pain. Total hip replacement was performed to all patients. Backache and lumbar lordosis were measured by visual analogue scale and Cobb’s angle respectively both before and 6 months after surgery. Patients were divided into 3 groups according to grade of improvement in backache after surgery.Results: The improvement in low back pain after surgery was statistically significant for all patients and for each group separately, while the changes in lumbar lordosis were not statistically significant neither for all patients nor for any group separately.Conclusions: total hip replacement surgery has significant positive effect on backache. There is no significant correlation between improvement in backache and changes in lumbar lordosis.

هل ان التغيرات في الالام اسفل الظهر ترتبط بتغيرات الوضع الجانبي للفقرات القطنية بعد عملية تبديل مفصل الورك الكامل ؟

الخفية : ان مفصل الورك والفقرات القطنية مرتبطين من حيث الوضع التشريحي والوظيفي كما اثبته الكثير من المؤلفين.وان اي خلل بمنطقة معينة سيؤدي الى خلل بالمنطقة الاخرى فمثلا سوفان مفصل الورك قد يؤدي الى تغيير بالوضع الجانبي للفقرات والالام الظهر. الهدف : هو معرفة هل يحصل تحسن مهم احصائيا في الالام الظهر بعد عملية تبديل مفصل الورك الكامل ؟ واي درجة من التحسن بالالام الظهر تكون مرتبطة بتغييرات مهمة احصائيا في الوضع الجانبي للفقرات القطنية ؟ المرضى والطرق: اجريت هذه الدراسة المستقبلية على 30 مريض كانوا يعانون من سوفان مفصل الورك المتقدم والالام اسفل الظهر المزمنة,تم اجراء عملية تبديل مفصل الورك الكامل لكل المرضى, وتم قياس درجة الالام الظهر وزاوية الانحناء الجانبي للفقرات القطنية قبل العملية وبعد 6 اشهر من العملية , وتم تقسيم المرضى الى ثلاث مجاميع حسب درجات التحسن بالالام الظهر. النتائج : التحسن بالالام اسفل الظهر بعد العملية كان مهم احصائيا لكل المرضى ولكل المجاميع, بينما التغيير بزاوية الانحناء الجانبي للفقرات القطنية بعد العملية لم يكن مهم احصائيا لكل المرضى ولكل المجاميع. الاستنتاجات : عملية تبديل مفصل الورك الكامل لها تاثيرات ايجابية مهمة احصائيا على الالام اسفل الظهر. لاتوجد علاقة مهمة احصائيا بين التحسن بالالام الظهر والتغييرات بزاوية الانحناء الجانبي للفقرات القطنية.

Hybrid Circumferential Fixation for Degenerative Lumbosacral Spine Disease

Retrospective study on circumferential hybrid instrumentation with posterior lumbar interbody fusion (PLIF) and the novel posterior Universal Clamp (UC) instrumentation. This study evaluated the roentgenographic and clinical outcome after PLIF with PEEK cage augmented with UC posterior sublaminar fixation without posterior fusion. Although UC has been successfully used in scoliosis surgery, to our knowledge, this is the first report on its use in degenerative lumbosacral disease. Rigid pedicle screw lumbosacral fixation is associated with several intraoperative screw-related complications. The use of sublaminar bands and rods combined with PEEK PLIF should increase fusion rate and avoid screw-related complications. From a total of 295 consecutive patients who experienced degenerative lumbosacral disease and received posterior decompression, implantation of PLIF with PEEK cages and semirigid posterior fixation with sublaminar UC bands-rods without posterolateral fusion, 150 patients were eligible for this study with a follow-up of more than 2 years. Interbody fusion rate and global plus segmental sagittal spinal lordosis restoration were recorded pre- and postoperatively. Visual analogue scale and Oswestry Disability Index were used to assess functional outcome. Hybrid instrumentation expanded over 1 to 5 levels. Surgical time ranged from 45 to 225 minutes. Only 12.6% of the patients were transfused. There was no nerve root lesion or deep wound infection. Laminar fracture occurred intraoperatively in one case during band insertion. Interbody fusion was achieved in 94% of the operated segments. Lumbar lordosis improved from -36 ± 9° preoperatively to -53 ± 6° postoperatively. Segmental lordosis improved in L4-L5 segment from -5 ± 3° preoperatively to -12 ± 2° postoperatively and in L5-S1 from -9 ± 4° to -14 ± 2° postoperation. Oswestry Disability Index score improved from 44.9 preoperatively to 2.2 postoperatively (P < 0.001). No patient required further spinal surgery until the final evaluation. UC, a novel semirigid sublaminar posterior instrumentation, combined with wedge-shaped PEEK PLIF corrected both global and segmental sagittal lumbar alignment and achieved fusion rate similar to that historically reported with pedicle screw-PLIF techniques, however, avoiding intraoperative complications associated with the use of pedicle screws.

Lumbar alignment and clinical outcome after single level asymmetrical transforaminal lumbar interbody fusion for degenerative spondylolisthesis with local coronal imbalance.

Transforaminal lumbar interbody fusion (TLIF) is widely accepted for the treatment of lumbar arthrodesis. However, the exact characteristics of TLIF depend on the number, location, shape, or materials of the interbody implants, and the type of posterior instrument. Clinical and biomechanical characteristics of each TLIF procedure are still unclear. The present study investigated the clinical and radiological improvements after single level asymmetrical TLIF, in which a single box-shaped spacer was obliquely inserted into the intervertebral space, for lumbar degenerative spondylolisthesis in patients with or without local coronal imbalance (LCI) at the operated level. The clinical records of 60 patients who underwent single level asymmetrical TLIF augmented with the pedicle screw fixation system from January 2005 to January 2011, were retrospectively reviewed. The patients were divided into the LCI group (n = 19) and non-LCI group (n = 41), based on segmental lateral translation or disc wedging at the operated site. Clinical recovery was significantly good in both groups at 2 years after surgery, but improvement of low back pain was significantly worse in the LCI group. Radiological examination revealed that the mean lumbar scoliotic angle was significantly worse in the LCI group postoperatively. Preoperative greater scoliotic angle and coronal off balance of the lumbar spine were related to unfavorable radiological outcomes. The present study showed that single level asymmetrical TLIF is an acceptable method for achieving good clinical and radiological outcomes for patients with symptomatic degenerative spondylolisthesis, however, the clinical benefits and realignment are limited if the patient has LCI at the operated site with greater scoliotic angle or coronal off balance of the lumbar spine.

The result of S1 double screw fixation in patients not suited for L4 and/or L5 pedicle screw insertion

Variable methods are available for sacropelvic fixation. The usefulness of S1 double screw fixation for deformity surgery is established, but its effectiveness in cases where the L4 and/or L5 pedicle screw is not appropriate has not been reported. We reviewed medical records to identify long-segment, lumbar spine fixation involving S1 double screws. Nine such patients were treated between November 2006 and November 2012 at our center: all patients had infectious spondylitis involving L4 and/or L5. Two patients were excluded due to a limited follow-up period (< 6 months). The remaining seven patients were enrolled. We used dynamic X-rays or three-dimensional computed tomography (3D-CT) to assess any change in the lumbar alignment angle and to evaluate bony fusion with the graft material. The mean observation period of the seven patients was 16.9 months (range: 6-25). The mean age was 63.43 years (range: 55-73). Four patients were women. The average number of fusion levels was 3.5 ± 1.1. The ideal positioning and maintenance of the S1 double screws and bony fusion with the graft materials were confirmed using serial imaging. Lordosis in the lumbar region was immediately restored after surgery (27.0 ° ± 10.4 to 35.1 ° ± 10.7), and maintained with slight decrease (31.6 ° ± 8.8) throughout the follow-up period. S1 double screws provided stability when L4 and/or L5 pedicle screw fixation was not possible. Our results suggest that S1 double screws are a viable option for sacropelvic fixation in selected patients.

Change in Spinal Alignment after Total Hip Arthroplasty

The study hypotheses were that: (i) there would be a difference in sagittal plane alignment between patients with symptomatic osteoarthritis of the hip and those with lumbar degenerative disk disease; and (ii) that sagittal plane lumbar alignment would change following total hip arthroplasty (THA). In this prospective study, a series of patients without back pain or lumbar complaints who were scheduled to undergo THA underwent lateral lumbar radiography prior to and nine months after elective THA. Radiographic measurements of lumbar alignment included sacral slope, lumbar lordosis, and L1 axis S1 distance (L1 ASD). All measurements were performed on upright, standing, lateral radiographs. A control group of patients underwent serial radiography over the same period for evaluation of lumbar degenerative disease. The independent sample t-test was used to compare the mean sacral slope, lumbar lordosis, and L1 ASD in the THA and control groups. There were 12 patients in the THA group and 34 in the control group. Mean follow-up was 9 months. Average age in the control group was 63 years and in the THA group 64.2 years. The sacral slope was greater in the THA group (mean, 23°) than in the lumbar patients (control group) and this difference was statistically significant (mean, 11°, P = 0.001). There were no statistically significant differences between THA and control patients in lumbar lordosis or L1 ASD. Change before and after THA was measured. There were no statistically significant differences in assessed radiographic variables preoperatively versus postoperatively. There is no significant change in spinal alignment after unilateral THA. At baseline, patients with symptomatic spine complaints have less sacral slope than their hip arthroplasty counterparts.

SAT0430 Tight hamstrings of young athlete change lumbar spinal alignment kyphoscoliosis in the kick position: A new radiographic evaluation for lumbar spine in anteroposterior and lateral view under dynamic straight leg raising

BackgroundLumbar spondylolysis is very frequency disorders of young athletes, particularly those involved in baseball, football, weight-lifting, and track & field. The rate of occurrence may be greater in Japanese subjects,...

Sagittal Lumbar Alignment Following Axial Lumbar Interbody Fusion with TranS1

Design: Retrospective study. Objective: To examine and compare pre/postoperative sagittal alignment of the lumbar spine following AxiaLIF® and to identify patient category with respect to preservation/restoration of lumbar lordosis. Background: Interbody arthrodesisis an effective treatment for lower back pain and provides immediate structural support with high fusion rates. AxiaLIF® is an interbody device to be implanted through a paracoccygeal approach. Sagittal alignment change after AxiaLIF® has not been studied in past literature. Methods: Retrospective study of all patients who underwent a 360° lumbar interbody fusion at L5-S1 and L4-S1 with AxiaLIF® between Nov. 2008 and Sept. 2009. Surgeries were performed with patients prone on a Jackson table. Lumbar Cobb angles were measured at L1-S1, L4-S1 and individual lumbar levels. The sacral slope and percentage of total lordosis coming from the L4-S1 levels were also recorded. Results: 60 patients identified for inclusion (mean age: 44 years). No difference in total average lordosis was observed preoperatively (47.9o) versus postoperatively (47.7o). The difference between pre and postoperative Cobb angles at the L4-S1 and L4-L5 levels was statistically significant (p=0.022 and 0.029, respectively). The change in percentage of total lordosis coming from L4-S1 segments (68.9% preoperatively vs. 56.5% postoperatively) was also significantly different (p=0.0004). A >10o postoperative change in total lordosis, L4-S1, and SS occurred in 18%, 20%, and 11% respectively. 50% and 43% of patients had a >5o change at the individual segments of L4-L5 and L5-S1. Conclusions: A significant portion single and multilevel fusions with AxiaLIF® had a statistically significant change at the L4-5 and L4-S1 levels. The percentage of total lordosis from the L4-S1 level decreased significantly in the multilevel group. Further observation will determine if change in alignment will impact outcomes or accelerate adjacent level disease.

Sagittal lumbar and pelvic alignment in the standing and sitting positions

BackgroundThe sitting position has become the most common posture in today’s workplace. In relation to this position, kinematic analysis of the lumbar spine is helpful in understanding the causes of low back pain and its prevention. MethodsIn this study, we investigated the relationship between sagittal lumbar alignment and pelvic alignment in the standing and sitting positions for 50 healthy adults. Lumbar lordotic angle (LLA), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI) were measured on lateral lumbar spine standing and sitting radiographs. ResultsRegarding changes from the standing to sitting positions, averageLLA, SS, and PT were −16.6° (−49.8 %), −18.7° (−50.3 %), and 18.3° (284.8 %), respectively (P < 0.01). In the sitting position, lumbar lordosis was reduced and pelvic rotation became posterior. ConclusionsThis study showed that LLA decreased by approximately 50 % and PT increased by approximately 25 % in the sitting position compared with the standing position. No significant gender differences were observed for LLA, SS, and PT in the standing position. In the sitting position, however, LLA and SS were markedly larger for women.

Effect of Cage Geometry on Sagittal Alignment after Posterior Lumbar Interbody Fusion for Degenerative Disc Disease

To compare the sagittal alignment of the lumbar spine after one-segment posterior lumbar interbody fusion (PLIF) using the horizontal cylinder (HC) or open box (OB) type cage. 66 patients underwent instrumented one-segment PLIF with bone grafting for lower lumbar degenerative disease. HC-type cages were used in 33 men and 13 women aged 20 to 73 (mean, 47) years between September 2001 and July 2004. OB-type cages with a 3-degree lordotic angle were used in 9 men and 11 women aged 25 to 70 (mean, 53) years between July 2004 and September 2006. Pre- and post-operative lumbar lordosis and intervertebral body angles in the fused and upper adjacent levels in the 2 groups were compared. There was no significant difference between the 2 groups with regard to changes in the lumbar lordosis and intervertebral body angle in the fused and upper adjacent levels. In both groups, the upper adjacent intervertebral body angle increased significantly by about 2 degrees. Lumbar alignment was similar after the use of the HC- or OB-type cages. This may be due to the surgical procedure and insufficient cage lordotic angle.

股関節伸展可動域の大きさによる上位および下位腰椎の前彎増強の違い

Decrease in the hip extension range of motion (HE-ROM) can cause lumbar hyperlordosis. Hyperlordosis is one of the mechanisms underlying low back pain. A diagnosis of low back pain from hyperlordosis can be used to detect the area in which hyperlordosis occurs more easily—the upper or lower lumbar spine. Twenty-one men were recruited for this study. HE-ROM was measured manually. Lumbar alignment was measured on a bed in a prone position. We extended the subject's hip by bending the bed at 4 angles (0°, 10°, 15°, 30°) and measured the spinal alignment by using a SpinalMouse. The results showed that lumbar lordosis increased at the bed angles of 15°and 30°. Only when the bed angle was changed from 0° to 30°, the increased angle of the lumbar spine was negatively correlated to the HE-ROM (r=-0.46, p<0.05), particularly that of the lower lumbar spine (r=-0.47, p<0.05). These findings suggested that lower lumbar lordosis tends to increase in individuals with poor HE-ROM. Additionally, increase in lower lumbar lordosis is attributed to the tendency to have low back pain in the lower lumbar spine.

Sublaminar wiring stabilization to prevent adjacent segment degeneration after lumbar spinal fusion

Adjacent segment degeneration (ASD) is a complication of lumbar spinal fusion. There are some reports on the cause of this degeneration but none concerning its prevention. We performed sublaminar wiring stabilization to prevent ASD after posterolateral lumbar spinal fusion with instrumentation. The purpose of this study was to prospectively evaluate the efficacy of this procedure. Between 2003 and 2004, 54 consecutive patients with lumbar spinal canal stenosis and multilevel instability of the lumbar spine underwent posterior decompression and posterolateral fusion with instrumentation. The mean age at the time of surgery was 66.7 +/- 1.3 years, and the mean follow-up period was 40.0 +/- 1.1 months, with a minimum of 29 months. Twenty-seven of the patients underwent conventional sublaminar wiring stabilization at the cephalad segment adjacent to the site of fusion to prevent ASD (group A), and the other 27 patients did not (group B). Some items were assessed, including clinical outcome using Japanese Orthopaedic Association (JOA) score, sagittal global lumbar alignment, and segmental motion in flexion-extension radiographs of the cephalad vertebral body adjacent to the site of fusion. There were no significant differences in JOA scores between two groups, but 2 patients in group B underwent subsequent surgery due to ASD. Sagittal lumbar alignment did not change in group A but was significantly decreased in group B. With respect to segmental motion in flexion-extension radiographs, group A showed a significant decrease from 6.9 degrees before surgery to 3.4 degrees after surgery, on the other hand group B showed a significant increase from 5.6 degrees before surgery to 8.4 degrees after surgery. In this study, it was suggested that sublaminar wiring stabilization significantly reduces the range of motion of the adjacent segment and preserves sagittal lumbar alignment, which lead to prevention of ASD. The clinical outcome of the subsequent surgeries is relatively poor, so it is important to prevent ASD by any prevention such as sublaminar wiring stabilization.

Comment on “Long-term actuarial survivorship analysis of an interspinous stabilization system” (J. Sénégas et al.)

This paper evaluates the survivorship of interspinous implants implanted in association with a decompression procedure of the lumbar spine, either discectomy or fenestration, at a mean 14-years’ follow-up. It gives important information about the safety of the procedure concerning possible short and long-term complications linked to the device itself. It is also noteworthy that only 10% of the patients secondarily needed adjacent-level surgery. However, this study has a number of shortcomings. Only 59% of the patients were available for follow-up and the information about removal of the device or other subsequent operation at the operated or at an adjacent level was obtained through a telephone interview, information being obtained through close relatives in the case of patient’s death. It is common in daily practice to observe that patients do not always fully understand the nature of an operation they undergo, if the information about the removal or not of the implant is probably reliable the exact nature of another surgical procedure and the level of this procedure may be questioned. The authors state that patients who underwent the placement of an interspinous implant would have been scheduled for a fusion in association with the decompression procedure, the indication being instability or associated low back pain. They report outcomes at least equal to those of fusion, which is understood by the reader as clinical outcome, including at least partial relief of low back pain if present initially. On two occasions, the notion of outcome in the text clearly not only relates to survival of the implants. However, there is very little information on the clinical status of the patients preoperatively and at last follow-up regarding low back pain. Even regarding the preservation of stability at the instrumented level, outcome assessment should include systematic preoperative, postoperative and long-term follow-up radiographs, ideally with dynamic views. The long-term preservation or restoration of sagittal lumbar alignment would have interestingly been documented by radiographs in a significant number of patients. Regarding the rate of reoperation at long term for adjacent level problems, a 10% rate is encouraging; however, it must be balanced with another 11% reoperation rate at the level of the index procedure, which is probably a much higher reoperation rate than after fusion. Overall, the need for another operation, at the same level or at an adjacent level, does not appear to be very different than after initial fusion; however, a number of secondary operations could have been less invasive than after fusion procedures. In conclusion, I believe this paper gives important information about the safety of implanting an interspinous device of the Wallis type, about the absence of significant complications related to the implant and the technique themselves, but it gives no undebatable information on the indications to associate such a procedure with a decompression operation, neither does it permit to truly compare the result on low back pain after a fusion. The indication of a stabilisation procedure when performing a discectomy or a laminectomy remains a matter of debate; the safety of an interspinous implant when compared to an instrumented fusion does not allow the surgeon to supplement his indications for an associated stabilisation procedure in these circumstances. Moreover the results of this paper certainly do not support the indication of using such a device to treat low back pain per se. To perfectly ascertain the pertinence of interspinous devices, randomised prospective studies comparing patients with decompression alone, decompression with dynamic stabilisation and decompression with fusion (posterior or interbody?), are required.