Kickstand rods and correction of coronal malalignment in patients with adult spinal deformity

Purpose

Coronal malalignment (CM) is a challenging spinal deformity to treat. The kickstand rod (KR) technique is powerful for correcting truncal shift. This study tested the hypothesis that the KR technique provides superior coronal alignment correction in adult deformity compared with traditional rod techniques.

Methods

A retrospective evaluation of a prospectively collected multicenter database was performed. A 2:1 matched cohort of non-KR accessory rod and KR patients was planned based on preoperative coronal balance distance (CBD) and a vector of global shift. Patients were subgrouped according to CM classification with a 30-mm CBD threshold defining CM, and comparisons of surgical and clinical outcomes among groups was performed.

Results

Twenty-one patients with preoperative CM treated with a KR were matched to 36 controls. KR-treated patients had improved CBD compared with controls (18 vs. 35 mm, P < 0.01). The postoperative CBD did not result in clinical differences between groups in patient-reported outcomes (P ≥ 0.09). Eight (38%) of 21 KR patients and 12 (33%) of 36 control patients with preoperative CM had persistent postoperative CM (P = 0.72). CM class did not significantly affect the likelihood of treatment failure (postoperative CBD > 30 mm) in the KR cohort (P = 0.70), the control cohort (P = 0.35), or the overall population (P = 0.31).

Conclusions

Application of the KR technique to coronal spinal deformity in adults allows for successful treatment of CM. Compared to traditional rod techniques, the use of KRs did not improve clinical outcome measures 1 year after spinal deformity surgery but was associated with better postoperative coronal alignment.

     

Dysfunctional paraspinal muscles in adult spinal deformity patients lead to increased spinal loading

European Spine Journal - Decreased spinal extensor muscle strength in adult spinal deformity (ASD) patients is well-known but poorly understood; thus, this study aimed to investigate the...     

青少年特发性脊柱侧凸患者术后放射学参数和SRS-22评测结果的相关性研究

目的 探讨青少年特发性脊柱侧凸(AIS)术后患者放射学参数与SRS-22量表各维度得分的相关性.方法 95例术后患者(13男,82女)分为2组:胸弯组64例,胸腰弯/腰弯组31例,平均随访时问为2.8年.所有患者行脊柱全长正侧位检查,并填写一份SRS-22量表.在脊柱全长正侧位片上测量放射学参数,计算AIS患者放射学参数与SRS一22四个维度得分间的Spearman等级相关系数(rs).结果 脊柱力线偏移、胸椎后凸角和腰椎前凸角这三个参数与SRS-22各维度得分不存在相关性.胸腰弯/腰弯组的主侧凸残余Cobb角与SRS-22各维度得分同样不存在相关性.胸弯组主侧凸残余Cobb角与自我形象维度得分呈负相关(rs=-0.411,P=0.001).结论 主侧凸为胸弯的AIS术后患者残余Cobb角越大,其SRS-22量表自我形象维度的得分越低.应当尽可能多地矫正胸弯的畸形以改善患者的外观.     

Flexibility of thoracic kyphosis affects postoperative sagittal alignment in adult patients with spinal deformity

Proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) surgery patients is a severe complication with potential need for revision surgery. While thoracic kyphosis (TK) is known to influence PJK, the role of TK flexibility is still unknown. We analyzed the influence of TK flexibility to predict postoperative sagittal alignment. Patients with ASD, ≥ 2-year follow-up, and upper-most instrumented vertebra (UIV) including and below T10 were included in this retrospective study. TK flexibility, defined as > 10° difference of the TK in standing and supine imaging, was analyzed. Patient characteristics like age, sex, weight, total hip arthroplasty, and sagittal alignment parameters were studied. Sixty-five patients aged 66 ± 8 years were included in the study. Lowest instrumented vertebra was S1 or the ilium in 85% of them; the number of levels being fused averaged 7. Flexible TK was present in 31% (n = 20). These patients had a larger preoperative TK (p < 0.01), but no PJK was found (p = 0.04). In contrast, patients who underwent revision surgery had a decreased TK flexibility (p = 0.04) and increased PJK angle at follow-up (p = 0.01). In the non-flexible patients, the PJK was found in 14% of patients. Based on our retrospective data, TK flexibility influences the outcome of ASD surgery. In patients demonstrating no TK flexibility, a more cephalad UIV-level should be considered because spontaneous curve correction in the sagittal plane might be low in these patients. This new parameter should be included in future prediction models. These slides can be retrieved under Electronic Supplementary Material.     

Walking balance and compensatory gait mechanisms in surgically treated patients with adult spinal deformity

Background Context

Gait patterns and their relationship to demographic and radiographic data in patients with adult spinal deformity (ASD) have not been fully documented.

Comparison of adult spinal deformity patients with and without rheumatoid arthritis undergoing primary non-cervical spinal fusion surgery: a nationwide analysis of 52,818 patients

Background Context

Numerous studies have analyzed the impact of rheumatoid arthritis (RA) on the cervical spine and its related surgical interventions. However, there is a paucity of literature available conducting the same analyses in patients with non-cervical spine involvement.

成人脊柱畸形术前冠状面失平衡及其与脊柱-骨盆影像学参数的关系

目的:测量成人脊柱畸形(adult spinal deformity,ASD)患者术前脊柱-骨盆参数,探讨ASD患者术前脊柱-骨盆参数与冠状面失衡的相关性。方法:回顾分析161例ASD患者的术前影像学资料,在站立位脊柱全长正、侧位X线片上测量影像学参数,冠状位参数包括主弯角度(Cobb角)、代偿弯角度(compensatory angle,CCobb角)、侧凸方向(左或右)、侧凸累及椎体数(vertebra number,VN)、侧凸椎体半脱位程度(subluxation degree,SD)、侧凸顶椎旋转度(apex rotation,AR)、顶椎位置、C7铅垂线(C7PL)到S1中点的距离(coronal balance distance,CBD);矢状位参数包括胸椎后凸角(TK)、胸腰段后凸角(TLK)、腰椎前凸角(LL)、骶骨角(SS)、骨盆倾斜角(PT)、骨盆入射角(PI)、矢状面平衡(SVA)。将患者分为失衡组(CBD30.00mm,A组)和平衡组(CBD30.00mm,B组),χ2检验比较两组患者比例参数,t检验比较两组影像学参数。结果:161例ASD患者的年龄为45～79岁(63.9±8.4岁),男女比为29∶132(M∶F),侧凸方向106∶55(左∶右),冠状面失衡组31例(男8例,女23例),平衡组130例(男21例,女109例),总失衡率为19.25%(31/161)。侧凸顶椎大多处于L2～L3节段,约占75.16%(121/161)。失衡组和平衡组患者年龄、性别比、左右侧凸比例、TK、TLK、LL、SS、PT、PI及SVA均无显著性差异(P0.05),两组侧凸顶椎位置有显著性差异(χ2=12.692,P0.001),失衡组顶椎位置均处于L2～L3节段;两组患者主弯及代偿弯Cobb角均无显著性差异(P0.05),但失衡组患者NV少于平衡组(3.87±0.85vs 4.36±0.95;t=2.639,P=0.009);失衡组患者AR大于平衡组(2.81±0.60 vs 2.32±0.77;t=-3.796,P0.001),TLK大于平衡组(t=-2.445,P=0.017)。将顶椎处于L2～L3节段的121例患者分为失衡组(CBD30.00mm,A′组,31例)和平衡组(CBD30.00mm,B′组,90例),两组主弯Cobb角、C-Cobb角无显著性差异(P0.05);A′组患者主弯累及椎体数明显少于B′组(3.87±0.85 vs 4.23±0.85;t=2.052,P=0.04);A′组患者AR明显大于B′组(2.81±0.60 vs 2.27±0.68;t=-3.905,P0.001)。结论:约1/5的ASD患者术前冠状面失平衡,且侧凸顶椎均位于L2～L3节段;侧凸角度相似、顶椎旋转度较大、侧凸累及椎体数目较少的患者更易出现冠状位失平衡。     

成人脊柱侧凸分型方法与手术治疗策略

近年来,学者们通过应用影像学资料与(或)临床资料提出了多种用于规范成人脊柱畸形治疗策略的分型系统,旨在为更精确地比较不同类型成人脊柱畸形的治疗手段与临床疗效。本文通过回顾分析着重介绍几种成人脊柱侧凸分型系统,包括:成人退变性脊柱侧凸Faldni分型、SRS分型系统、Schwab分型、Scoliosis Research Society-Schwab分型系统,以及退变性腰椎侧凸的冠状面失衡分型等。以探讨不同分型方法对手术策略的指导价值,以及对存在的问题等进行全面概述。由于成人脊柱侧凸在影像学表现、临床症状表现、病理形态以及病理生理方面等关系较为复杂,因此制定出一种能够指导临床治疗的成人脊柱侧凸分型系统依然是脊柱外科领域的一大难题。     

Outcome assessment of bracing in adolescent idiopathic scoliosis by the use of the SRS-22 questionnaire

The SRS-22 questionnaire is specifically designed for the assessment of quality of life in spinal deformity patients. This study is the first to use it to assess the quality of life of adolescent idiopathic scoliosis patients under brace treatment and compares the results with an observational group matched by age and curve magnitude. Forty-six patients were enrolled into each group. Overall, it was found that patients under observation had a significantly better quality of life than braced patients. Specifically, the domains for function/activity and self-image were most affected. This effect was most apparent in those with a curve magnitude of under 20 degrees . The scores did not improve significantly with the duration of brace wear, suggesting little adaptation. This study has implications for treatment, and more attention will need to be given to those with mild but progressive curves to help improve patients' understanding of their treatment and hence their compliance and satisfaction.     

Relationships between radiographic parameters and spinopelvic muscles in adult spinal deformity patients

While the clinical impact of coronal and sagittal alignment in adult spinal deformity (ASD) patients (pts) is established, there is a paucity of data in terms of axial plane deformity and potential association between muscle degeneration and 3D deformity. The purpose of this study was to analyze spinopelvic muscles characteristics in association with the 3D deformity of ASD patients. This is a prospective cohort study; primary lumbar scoliosis patients (Cobb > 20°) were enrolled and sustained a low-dose X-rays with 3D spinal reconstructions and a fat/water separation MRI (from C7 to the knee).Volumetric 3D reconstructions and fat infiltration (FI) of 6 muscles groups were performed. Relationships between muscular data, radiographic parameters and health-related quality of life were investigated. Patients were stratified and compared based on the SRS classification, the odontoid-hip axis (ODHA) angle (> or < 6.1°) and occurrence of rotatory subluxation. Twenty-eight patients were enrolled with a mean age of 60 ± 16yo and mean body mass index of 26 ± 4 kg/m2 without differences between groups. There were a moderate sagittal malalignment and a Cobb angle of 45 ± 11° (table). Muscular volume was smaller in patients with more severe deformity (p > 0.05). Pts with ODHA > 6.1° or pelvic incidence minus lumbar lordosis  > 10° had significantly higher FI for the 6 muscular groups, patients with pelvic tilt  > 20° had significantly higher FI for erector spinae, hip flexors and extensors (p < 0.05). SF36-PCS significantly correlated with the muscular volume; SRS and Oswestry disability index correlated with the erectors spinae volume (p < 0.05). This study analyzed for the first time the relationship between 3D radiographic parameters and muscular characteristics in ASD. Sagittal malalignment is associated with increased FI and decreased muscle volumes with poor outcomes. These slides can be retrieved under Electronic Supplementary Material.     

Sagittal malalignment has a significant association with postoperative leg pain in adult spinal deformity patients

Purpose

To evaluate the association between spinopelvic sagittal parameters and leg pain in patients with adult spinal deformity (ASD) after adjusting for demographic and surgical variables.

Methods

A multicenter prospective ASD database (European Spine Study Group) was retrospectively reviewed. The characteristics (age, sex, body mass index, comorbidity, history of spine surgery, and radiographical coronal and sagittal parameters) of patients with preoperative and 6-month postoperative leg pain (PostLP; numerical rating scale score ≥5) were analyzed using univariate and multivariate analyses.

Results

In this study, 204 patients (164 women and 40 men; mean age 53.1 years) were included. Fifty-three percent of the patients had preoperative leg pain (PreLP). The patients with PreLP had significantly worse sagittal parameters and less coronal Cobb angle than those with less leg pain; however, this association disappeared after adjustment for covariates. The PreLP of the ASD patients was successfully treated surgically in most cases; however, 24 % of the patients still had unexpected residual leg pain. Postoperative sagittal malalignment (sagittal vertical axis ≥40 mm, T1 sagittal tilt ≥0°, pelvic tilt ≥30°) was a significant risk factor of PostLP even after adjusting for covariates.

Conclusions

Leg pain in patients with ASD was significantly associated with sagittal malalignment especially after surgical treatments. As these patients lose flexibility in the fused spinal segment, they can only depend on the remaining compensatory mechanisms below the pelvis (e.g., the hips and knees) to maintain a balanced posture. This may lead to a predisposition of these patients to postoperative leg symptoms related to spinal sagittal malalignment.

     

Revision surgery for non-union in adult spinal deformity

As adult spinal deformity surgery is performed more and more, the spine surgeon is faced with the challenge to treat pseudoarthrosis. The presentation may vary, from asymptomatic patients, who should be observed in most of the cases, to patients with acute episode of broken rods, and or chronic pain with often trunk imbalance. In some instances, patients will present with neurologic symptoms. The evaluation of such patients must start with a good understanding of why the surgery failed first place. Poor host, smoking, lack of anterior column support, poor sagittal balance, lack of fusion, poor construct. Often a combination of all of the above is encountered. The workup for such cases consists of imaging studies (with often a CT myelogram as the excessive metal artifact will render the MRI imaging useless), nutrition labs, DEXA scan, EOS films and internal medicine or cardiology consult for risk stratification as this may represent major surgery. Indication of surgery is mostly based on pain and imbalance and/or poor function. The surgeon planning a revision adult deformity surgery has many tasks to perform: Identify and avoid the reasons that lead to failure of the previous surgeries. Plan the anterior column reconstruction either through posterior or anterior interbody fusion. Restore the global alignment through anterior or posterior osteotomies to achieve sagittal and coronal balance. Obtain a solid fixation with sufficient levels above and below the osteotomies sites with in some cases the use of pelvic screws and four rods (Quad-Rod) techniques. The use of bone graft (either autologous, allograft, bone graft enhancers and inducer) agents. The requirement of decompression either through a virgin spine or a previous laminectomy bed. Despite the extent of these surgeries and the potential for immediate postoperative complications, the outcome is in most cases satisfactory if these goals are achieved. In this review, the authors explore different scenarios for pseudoarthrosis in the adult spine deformity patient and the preferred treatment method to obtain the best outcome for every individual patient. These slides can be retrieved under Electronic Supplementary Material.     

Utility outcome assessment of pes planus deformity

Background

Despite being a common condition, there are no objective measures in the literature to reflect the burden of pes planus on affected individuals. Our primary objective was to evaluate this burden by recruiting a sample from the general population using validated utility outcome measures.

Factor analysis of the North American Spine Society outcome assessment instrument: a study based on a spine registry of patients treated with lumbar and cervical disc arthroplasty

Background contextStudies involving factor analysis (FA) of the items in the North American Spine Society (NASS) outcome assessment instrument have revealed inconsistent factor structures for the individual items.PurposeThis study examined whether the factor structure of the NASS varied in relation to the severity of the back/neck problem and differed from that originally recommended by the developers of the questionnaire, by analyzing data before and after surgery in a large series of patients undergoing lumbar or cervical disc arthroplasty.Study design/settingProspective multicenter observational case series.Patient sampleThree hundred ninety-one patients with low back pain and 553 patients with neck pain completed questionnaires preoperatively and again at 3 to 6 and 12 months follow-ups (FUs), in connection with the SWISSspine disc arthroplasty registry.Outcome measuresNorth American Spine Society outcome assessment instrument.MethodsFirst, an exploratory FA without a priori assumptions and subsequently a confirmatory FA were performed on the 17 items of the NASS-lumbar and 19 items of the NASS-cervical collected at each assessment time point. The item-loading invariance was tested in the German version of the questionnaire for baseline and FU.ResultsBoth NASS-lumbar and NASS-cervical factor structures differed between baseline and postoperative data sets. The confirmatory analysis and item-loading invariance showed better fit for a three-factor (3F) structure for NASS-lumbar, containing items on “disability,” “back pain,” and “radiating pain, numbness, and weakness (leg/foot)” and for a 5F structure for NASS-cervical including disability, “neck pain,” “radiating pain and numbness (arm/hand),” “weakness (arm/hand),” and “motor deficit (legs).”ConclusionsThe best-fitting factor structure at both baseline and FU was selected for both the lumbar- and cervical-NASS questionnaires. It differed from that proposed by the originators of the NASS instruments. Although the NASS questionnaire represents a valid outcome measure for degenerative spine diseases, it is able to distinguish among all major symptom domains (factors) in patients undergoing lumbar and cervical disc arthroplasty; overall, the item structure could be improved. Any potential revision of the NASS should consider its factorial structure; factorial invariance over time should be aimed for, to allow for more precise interpretations of treatment success.