Remodelling of the sacrum in high-grade spondylolisthesis: a report of two cases

Two young patients are described, who were operated on for high-grade spondylolisthesis. A good posterolateral fusion was achieved, without decompression and without reduction. The clinical course was favourable, the tight hamstring syndrome resolved. Disappearance of the posterior-superior part of the sacrum and of the posterior part of the L5-S1 disc was observed on comparing pre- and postoperative magnetic resonance (MR) images. This resulted in normalisation of the width of the spinal canal. Around the L5 nerve roots in the L5-S1 foramina some fat reappeared. These anatomical changes on MRI could play a role in the disappearance of clinical symptoms.     

Sagittal plane laxity following knee arthroplasty

We measured the sagittal laxity in 70 knee replacements at least six months after surgery, using a KT 1000 arthrometer. With an unconstrained prosthesis (the Oxford meniscal knee) anteroposterior stability was normal in joints known to have intact cruciate ligaments. There was increased laxity in those which lacked an anterior cruciate ligament. In knees with an intact anterior cruciate ligament, sagittal laxity did not increase with time.     

Sagittal plane deformity during femoral lengthening

The purpose of this study was to determine the incidence and degree of sagittal plane deformity that occurs during limb lengthening of the femur. Twenty-one patients (25 limbs) were identified who underwent femoral lengthening. The limbs were lengthened a mean of 6.1 cm, and mean follow-up was 1.5 years. The immediate postoperative deformity in the sagittal plane was 8.3°; this deformity did not progress during lengthening (P<.05). Mean displacement in the sagittal plane was 3.1 mm.Angular deformities, although typically small, can occur in the sagittal plane and may be accompanied by displacement. These deformities are usually present immediately postoperatively and typically do not worsen significantly with lengthening.     

Changes of the sacrum in severe spondylolisthesis: a possible key pathology of the disorder

Deficient development of the posterior lumbosacral portion has been thought to be a possible etiology of severe spondylolisthesis. However, the precise causes of the deformity have yet to be revealed. To our knowledge, progression of the disorder has not been discussed in the light of sacral changes on magnetic resonance imaging (MRI). The objectives of the present study were to document changes of the sacrum on MRI scans in patients with severe spondylolisthesis and to discuss the relation of these changes to the progression of deformities. Roentgenograms and MRI scans of 13 patients (10 women and 3 men) with severe spondylolisthesis were retrospectively reviewed. Average age at first MRI examination was 20 years (range, 12 to 50 years). The MRI scans commonly showed a defect at the antero-superior portion of the sacrum. This lesion seems to appear during the period of progression of slipping associated with lumbosacral kyphosis. The defect of the sacrum was considered a unique feature to discriminate this type of olisthesis from others. Taking into conside-ration the present results, the deformity can be called kyphospondylolisthesis. Received for publication on Feb. 9, 1999; accepted on June 21, 1999     

Sagittal plane deformity: Evaluation and management

Sagittal alignment is a critical component of the evaluation and management of adult spinal deformities. Loss of sagittal alignment may be the result of iatrogenic-induced deformity, metabolic bone problems, progression of idiopathic or neuromuscular deformities, posttraumatic, or de novo. Goals of reconstruction involve restoration of global sagittal balance and lumbopelvic harmony. Treating the deformity often involves long construct fusion to the sacropelvis. Often times, multilevel osteotomies as well as circumferential approaches are needed to adequately address the deformity. Failure to address sagittal plane deformities has been linked to poor patient reported outcomes from surgical management. However, even with correction, postoperative complications are common. These included proximal and distal junctional failure, pseudoarthrosis, and the need for future surgery.     

Sagittal plane positioning of the femoral component in total knee arthroplasty

The authors evaluated 623 total knee arthroplasties to determine the relationship between sagittal plane position of the femoral component and the final range of motion of the prosthetic knee. Two different prostheses were evaluated (Posterior Cruciate Condylar and A.G.C.) radiographically and functionally. Variation in sagittal plane position ranged from 20 degrees flexion to 20 degrees extension. No correlation between the sagittal plane position of the femoral component in either prosthesis and the final knee range of motion could be found. Sagittal plane femoral component position in the prostheses studied did not affect final range of motion when component position was between 20 degrees flexion and 20 degrees of extension.     

退行性腰椎滑脱症的矢状面形态分型及其临床意义

目的:基于矢状面形态特点对退行性腰椎滑脱症(degenerative spondylolisthesis,DS)进行分型,评价其在腰椎侧前方入路手术治疗DS中的指导价值。方法:回顾性分析2015年1月～2016年12月我院收治的37例L4 DS患者的临床资料,其中男15例,女22例;年龄50～67岁(58.5±9.5岁)。由3名观察者分别根据DS患者术前L4/5节段矢状面形态分为3型:(1)开口型,腰椎滑脱角(slip angle,SA)5。;(2)平行型,0°≤SA≤5°;(3)闭口型,SA0°。所有患者均采用侧前方腰椎椎间融合术(anterolateral lumbar interbody fusion,ALLIF)治疗,术中参照患者矢状位形态分型调整手术体位摆放、cage置入位置和固定等。测量术前及术后腰椎前凸角(lumbar lordosis,LL)、骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)和脊柱矢状面平衡(sagittal vertical axis,SVA);评估术前及术后末次随访时的腰痛和下肢痛疼痛视觉模拟评分(visual analogue scale,VAS)、腰椎Oswestry功能障碍指数(Oswestry disability index,ODI)和健康调查简表(the MOS item short from health survey,SF-36)评分。对3名观察者的分型结果进行Kappa—致性检验,并对各组患者临床资料进行统计学分析。结果:3名观察者之间分型的一致性Kappa值为0.826～0.894,观察者自身的一致性Kappa值为0.875～0.916,均高度一致。37例DS患者中开口型12例(A组),平行型17例(B组),闭口型8例(C组),术前各组间LL、PT、SS具有统计学差异(P0.05),C组LL、SS显著性低于其余两组(_P0.05;),各组间PI、SVA无统计学差异(P0.05);术后A、B组脊柱-骨盆矢状面参数均较术前无显著性变化(P0.05),而C组PT较术前显著性降低,SS、LL显著性增加(P0.05)。术前C组患者腰痛VAS显著大于其余两组(P0.05),术后各组腰痛、腿痛VAS,ODI及SF-36评分均较术前显著性改善(P0.05),其中C组腰痛VAS、0-DI和SF-36心理健康评分改善幅度均大于其余两组(P0.05)。结论:基于DS矢状面形态特点分型简单、方便且可信度高,根据DS不同分型制定相应的ALLIF治疗策略可以获得满意的临床疗效。     

Sagittal spinopelvic alignment and body mass index in patients with degenerative spondylolisthesis

The sagittal orientation and osteoarthritis of facet joints, paravertebral muscular dystrophy and loss of ligament strength represent mechanical factors leading to degenerative spondylolisthesis. The importance of sagittal spinopelvic imbalance has been described for the developmental spondylolisthesis with isthmic lysis. However, it remains unclear if these mechanisms play a role in the pathogenesis of degenerative spondylolisthesis. The purpose of this study was to analyze the sagittal spinopelvic alignment, the body mass index (BMI) and facet joint degeneration in degenerative spondylolisthesis. A group of 49 patients with L4–L5 degenerative spondylolisthesis (12 males, 37 females, average age 65.9 years) was compared to a reference group of 77 patients with low back pain without spondylolisthesis (41 males, 36 females, average age 65.5 years). The patient’s height and weight were assessed to calculate the BMI. The following parameters were measured on lateral lumbar radiographs in standing position: L1–S1 lordosis, segmental lordosis from L1–L2 to L5–S1, pelvic tilt, pelvic incidence and sacral slope. The sagittal orientation and the presence of osteoarthritis of the facet joints were determined from transversal plane computed tomography (CT). The average BMI was significantly higher (P = 0.030) in the spondylolisthesis group compared to the reference group (28.2 vs. 24.8) and 71.4% of the spondylolisthesis patients had a BMI > 25. The radiographic analysis showed a significant increase of the following parameters in spondylolisthesis: pelvic tilt (25.6° vs. 21.0°; P = 0.046), sacral slope (42.3° vs. 33.4°; P = 0.002), pelvic incidence (66.2° vs. 54.2°; P = 0.001), L1–S1 lordosis (57.2° vs. 49.6°; P = 0.045). The segmental lumbar lordosis was significantly higher (P < 0.05) at L1–L2 and L2–L3 in spondylolisthesis. The CT analysis of L4–L5 facet joints showed a sagittal orientation in the spondylolisthesis group (36.5° vs. 44.4°; P = 0.001). The anatomic orientation of the pelvis with a high incidence and sacral slope seems to represent a predisposing factor for degenerative spondylolisthesis. Although the L1–S1 lordosis keeps comparable to the reference group, the increase of pelvic tilt suggests a posterior tilt of the pelvis as a compensation mechanism in patients with high pelvic incidence. The detailed analysis of segmental lordosis revealed that the lordosis increased at the levels above the spondylolisthesis, which might subsequently increase posterior stress on facet joints. The association of overweight and a relatively vertical inclination of the S1 endplate is predisposing for an anterior translation of L4 on L5. Furthermore, the sagittally oriented facet joints do not retain this anterior vertebral displacement.     

退行性腰椎滑脱的小关节影像学结构特点

目的：观测退行性腰椎滑脱（ＤＳ）患者的小关节形态结构,探讨引起退变滑脱可能的局部因素。方法：观察并测量４４例Ｌ４退行性滑脱患者及５０晨滑脱患者的正侧位Ｘ线片上的小关节,包括：Ｌ１下关节空间距（Ｄ）与椎板腰部宽（Ｗ）之比、Ｌ４下关节突长度、小椎 角和小面的改变,对比分析其结构特点。结果．滑脱组Ｌ４／Ｗ／１,小 关节间隙接近矢状位,两组Ｌ４下关节突长度、小椎弓根角在统计学上有显著性差异。结论：下关节突     

Frontal plane configuration of the knee in children

During childhood the knee has been described to undergo a swing in the frontal plane from varus to valgus and then back towards neutral. The contention of a number of workers is that these frontal plane alterations are normal physiological changes and that when the child begins to stand this pendulum mechanism is needed to equalize physeal growth about the knee. This article examines the literature on the subject of physiological genu valgum and genu varum in children.     

儿童发育不良性重度腰椎滑脱手术复位后脊柱-骨盆矢状位序列改变

目的 :评估手术复位对儿童L5发育不良性重度滑脱患者脊柱-骨盆矢状位序列的影响。方法:回顾性分析13例行手术复位治疗的儿童L5发育不良性重度滑脱患者,其中男2例,女11例。均行减压复位内固定融合术。手术时年龄11.5±2.4岁(7~15岁)。采用配对样本t检验比较术前、末次随访时的滑脱程度(slip degree)、腰椎前凸角(lumbar lordosis,LL)、Boxall滑脱角(Boxall′s slip angle,BSA)、SDSG发育不良性腰骶角(Spinal Deformity Study Group dysplastic lumbosacral angle,SDSG-dys LSA)、骨盆投射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)的差异,评估手术复位后脊柱-骨盆矢状位序列的变化。结果:随访20.6±21.9个月(3~64个月),滑脱程度由术前的(76.01±15.65)%改善至末次随访时的(17.57±16.64)%(P0.01),滑脱复位程度为(58.44±16.31)%,其中4例Ⅲ度滑脱患者完全复位。11例患者行S1上终板拱顶样部分切除,平均切除程度为(30.16±14.54)%。术前、末次随访时的LL分别为74.75°±18.11°、57.77°±14.83°,BSA分别为48.98°±16.01°、19.56°±18.70°,SDSG-dys LSA分别为19.78°±20.19°、-1.72°±19.04°,SS分别为28.68°±23.21°、41.13°±15.67°,末次随访时均较术前有显著性改变(P0.05);PI分别为65.64°±19.88°、73.20°±18.85°,PT分别为36.88°±11.68°、32.03°±11.76°,末次随访时较术前无显著性改变(P0.05)。C7铅垂线距骶骨后上角距离(sagittal vertical axis,SVA)较术前减小。末次随访时10例后倾型骨盆患者中2例(20%)转变为平衡型骨盆。结论:手术复位可改善儿童L5发育不良性重度滑脱患者脊柱-骨盆矢状位序列,矫正腰骶部后凸畸形,改善骶骨-骨盆矢状位序列。     

Sagittal configuration of the spine and growth of the posterior elements in early scoliosis

The early changes of the sagittal alignment of the spine and the asymmetry between the posterior and anterior elements were determined on the basis of 134 lateral and 167 anteroposterior radiographs obtained from a control group and from patients with early scoliosis. The radiographs were allocated into four groups according to the degree of the Cobb angle. In thoracic curves with a Cobb angle of more than 8°, the kyphosis and the vertebral sagittal wedge angle decreased in comparison with the control group. The sagittal-wedge angle of the disc did not change significantly with increasing Cobb angle. The pedicle height in relation to the vertebral height, considered to represent the growth of the posterior element in relation to the growth of the anterior element, was not significantly different in the scoliotic groups as compared with the control group. The results indicate that changes of the sagittal configuration of the spine occur early in idiopathic scoliosis and that they are associated with disturbed growth of the vertebral body but not of the posterior elements. These findings seem to reflect a simulataneous deformation in the coronal and sagittal planes rather than a single growth disturbance in any specific plane.     

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.