Double level Chance-type fractures of spine in ankylosing spondylitis

Chance fractures are usually associated with seat belt injuries. Mechanism is always related to flexion-distraction at vertebral level. Double level Chance-type fractures have rarely been reported in published literature. We presented such a fracture at D10 and L3 level in a 38-year-old patient with ankylosing spondylitis. Management was done with posterior decompression and short segment fixation separately.     

Deformity planning for sagittal plane corrective osteotomies of the spine in ankylosing spondylitis

Ankylosing spondylitis (AS) may lead to a severe fixed thoracolumbar kyphotic deformity (TLKD) of the spine. In a few patients, the TLKD is so extreme that a corrective osteotomy of the spine may be considered. Several authors have reported the results of patients treated by a lumbar osteotomy, but there is no consensus on the level of the osteotomy and on the exact degree of correction required. This can be explained by the lack of quantification of the sagittal plane deformity, since compensation mechanisms of the lower extremities have to be reckoned with for the assessment of spinal sagittal balance in AS. Therefore, there is a need for a method of deformity planning for sagittal plane corrective osteotomies of the spine in AS. In this study, a biomechanical analysis and a newly developed planning procedure are presented and illustrated with two cases of AS. Sagittal balance of the spine was defined in relation to the physiologic sacral end plate angle using trigonometric terms. Nomograms were constructed to show the relationship between the correction angle, horizontal position of the C7 plumb line and the level of the spinal osteotomy. The surgical results of two patients were retrospectively analyzed with our method. It showed that the effect of a spinal osteotomy on the horizontal position of the C7 plumb line depends on the combination of correction angle and the level of osteotomy. In one patient, the achieved correction of the deformity proved to correct the sagittal spinal balance and the pelvic sacral endplate angle. In the other patient, the achieved correction was not sufficient. It is concluded that adequate deformity planning for sagittal plane corrective osteotomies of the spine in AS is essential for reliable prediction of the effect of a lumbar osteotomy on the correction of the spine. Received: 17 January 2000 Revised: 12 May 2000 Accepted: 22 May 2000     

Spinal fractures in patients with ankylosing spondylitis

Thirty-one consecutive patients with ankylosing spondylitis and spinal fractures were reviewed. There were 6 women and 25 men with a mean age of 60±11 years; 19 had cervical and 12 had thoracolumbar injuries. Of the patients with cervical fracture, two had an additional cervical fracture and one had an additional thoracic fracture. Three trauma mechanisms were identified: high-energy trauma in 13 patients, low-energy trauma in 13 and insufficiency fracture in 5. One-third of the patients suffered immediate neurological impairment, a further one-third developed neurological impairment before coming for treatment and only one-third remained intact. Two patients with thoracolumbar fractures had deteriorated neurologically due to displacements during surgery at other hospitals. All patients were treated operatively except the two patients with two-level cervical fractures, who were managed in halo vests. In the cervical spine both anterior and posterior approaches were employed. In the thoracolumbar spine the majority of the patients were initially treated using a posterior approach only. Complications were common. Of the 27 patients with neurological compromise, 10 had remained unchanged; 12 had improved one Frankel grade; 4 had improved by two Frankel grades; 1 had improved by four Frankel grades. We conclude that even minor trauma can cause fracture in an ankylosed spine. A high proportion of patients with spinal fractures and ankylosing spondylitis have neurological damage. The risk of late neurological deterioration is substantial. As the condition is very rare and the treatment is demanding and associated with a very high risk of complications, the treatment of these patients should be centralised in special spinal trauma units. A combined approach that stabilises the spine from both sides is probably beneficial.     

Cervical spine fractures in patients with ankylosing spondylitis: Importance of early management

IntroductionAnkylosing spondylitis (AS) affects 0.5% of the population. Alteration of the biomechanical properties of the spine related to AS explains the high prevalence of traumatic vertebral fractures and risk of instability. At admission, 65% of patients present neurological signs. There are no reported studies regarding secondary neurological deterioration. The aim of this study was to evaluate the rate of secondary neurological deterioration before surgical treatment of spine fracture in a context of AS.MethodsThis retrospective cases series consisted of patients admitted for traumatic cervical spine fractures or luxation in a context of AS between June 2007 and December 2012. Clinical status was evaluated using Frankel classification at time of trauma, at admission to the neurosurgery ward, as well as before and after surgery. Delay between trauma and admission, and between admission and surgery was recorded. Causes of morbidity, mortality and surgical management were discussed.ResultsDuring the study period, seven patients were admitted for traumatic cervical spine fracture or luxation. All patients were autonomous before trauma. Between trauma and transfer to neurosurgery ward, the status of four patients worsened. Mean delay between trauma and admission was 12.9 days (range 1 to 60 days). Between admission to neurosurgery ward and surgical treatment, two more patients worsened and only two patients remained autonomous. Mean delay between admission and surgery was 15.7 h (range 2 to 24 h). Neurological deterioration was due to both deterioration during transfer despite immobilization with a rigid cervical collar and failure of X-ray to reveal any fractures, in two and three cases respectively. After surgery, clinical status remained unchanged in two patients, four patients improved, and one patient worsened. Two patients died from respiratory failure a few days after surgery due to neurological deterioration. Five patients had a delayed diagnosis (> 24 h).ConclusionCervical spine fracture in AS is a serious condition with high instability. Our series emphasizes the necessity of early surgical treatment because of risk of secondary neurological deterioration in cases of delayed treatment. CT scan must be the gold standard for exploration of these patients.     

强直性脊柱炎颈椎骨折的手术治疗

目的研究强直性脊柱炎颈椎骨折或骨折脱位手术治疗的疗效、融合率及相关问题。方法回顾性研究1986年4月～2004年4月手术治疗的12例累及颈椎的强直性脊柱炎合并颈椎骨折或骨折脱位患者。采用美国脊柱损伤学会(ASIA)神经功能障碍评分进行神经功能评价,应用图形分析软件(Image-Pro Plus5．1)分别测量屈曲和仰伸位融合节段上下椎成角,计算两个角度的差值(作为椎间的运动参数,α角),按照美国食品药品监督管理局(FDA)对脊柱融合的定义,α角≥4°认为假关节形成(不融合)。对与手术有关的其它问题采用描述性研究。结果12例患者获得21～124个月(平均67．5个月)随访。9例神经损伤患者ASIA评分平均改善1．3级,除1例前路手术未行内固定外,所有融合手术均行内固定。前路融合术6例,α角为0°；后路融合术2例,α角为0～2．5°；联合前后路融合术1例,随访时均获骨性融合。3例拟行椎板成形术者,2例因“门轴”侧骨折被迫行椎板切除术。术后并发症：气胸、肺不张1例,经胸腔闭式引流5 d治愈；伤口延迟愈合1例；前路伤口内积血1例,经切开引流治愈。无死亡及严重并发症发生。结论强直性脊柱炎颈椎骨折或骨折脱位行手术治疗可以改善神经功能；对不稳定损伤,融合手术应行内固定,可以达到骨性融合；术前由于合并症多导致手术耐受性差,术后并发症多发。     

Fracture luxation of the cervical spine in patients with ankylosing spondylitis: six cases

BACKGROUND AND PURPOSE: Treatment of cervical spine fracture in patients with ankylosing spondylitis is difficult. Biomechanical changes related to ossified ankylosing spondylitis spine make cervical spine fractures highly unstable. They cover the entire width of the spine inducing multidirectional instability and the risk of neurological injuries. Treatment is more difficult that in the nonossified spine. Different treatments have been proposed including anterior stabilization, posterior stabilization, or both. METHODS: We reviewed retrospectively six cases of cervical fracture dislocation in patients with ankylosing spondylitis. RESULTS: There were five cases of C6C7 fracture dislocation and one case of C4C5 fracture dislocation. Four patients had neurological impairment at diagnosis. All patients underwent surgery. Two had anterior stabilization: one patient died and the other achieved bone healing. Four patients had anterior and posterior stabilization combined with a cervical brace for three months, for two and a halo cast for two, others because of persistent instability, with neurological injury in one. A neurological improvement was obtained in four patients. One patient was lost to follow-up. CONCLUSION: Surgical management of selected patients with ankylosing spondylitis and cervical spine fractures is challenging. Combined anterior and posterior stabilization should be considered for these fractures. A cervical brace must be associated with surgical treatment. With appropriate management, outcome can be favorable.     

Delayed presentation and diagnosis of cervical spine injuries in long-standing ankylosing spondylitis

Patients with ankylosing spondylitis (AS) are vulnerable to cervical spine fractures. Long-standing pain may mask the symptoms of the fracture. Radiological imaging of the cervical spine may fail to identify the fracture due to the distorted anatomy, ossified ligaments and artefacts leading to delay in diagnosis and increased risk of neurological complications. The objectives are to identify the incidence and risk factors for delay in presentation of cervical spine fractures in patients with AS. Retrospective case series study of all patients with AS and cervical spine fracture admitted over a 12-year period at Queen Elizabeth National Spinal Injuries Unit, Scotland. Results show that total of 32 patients reviewed with AS and cervical spine fractures. In 19 patients (59.4%), a fracture was not identified on plain radiographs. Only five patients (15.6%) presented immediately after the injury. Of the 15 patients (46.9%) who were initially neurologically intact, three patients had neurological deterioration before admission. Cervical spine fractures in patients with long-standing AS are common and usually under evaluated. Early diagnosis with appropriate radiological investigations may prevent the possible long-term neurological cord damage.     

Posterior fixation of subaxial cervical spine fractures in patients with ankylosing spondylitis

Cervical spine fractures in patients with ankylosing spondylitis are serious and potentially lethal injuries with high complication rates. Treatment obstacles include long lever arms that generate large forces on any fixation device, osteoporosis, and, usually, kyphotic deformity. The Olerud Cervical Fixation System (OC), with cervical pedicle screws and rods, offers an opportunity to create a biomechanically stable posterior fixation in these complicated cases. The present study is a retrospective chart review and a radiological follow-up of patients with this diagnosis, treated at our department between 1995 and 2000. Nineteen patients (two women) with a mean age of 60 years (32–78 years) were included. The fracture levels were predominantly C5–C6 (five patients) and C6–C7 (five patients). All patients were treated with a long posterior fixation with the OC, and in four patients this was combined with an anterior plate fixation. One patient with severe lordosis also received a short posterior plate fixation. The patients notes and plain radiographs have been reviewed. Five patients died during the post-operative follow-up period; the others had a mean follow-up time of 24 months (10–55 months). Eleven patients had no neurological deficits preoperatively. One of them developed moderate weakness in his right arm, postoperatively, due to a misplaced pedicle screw in the right pedicle of C5. However, after extraction of the screw he almost totally recovered in 6 months. Eight patients had neurological deficits. Two were paraplegic; two had motor weakness combined with sensory deficiency, and four had a sensory deficiency. Two of the patients with neurological deficits improved postoperatively, but the others were unchanged. Peroperative problems were recorded in five patients; one C6 pedicle was perforated, and two patients had pedicles on one or more levels that the surgeon was not able to probe. In one of the latter patients, transfacet screws were chosen, instead, for one of the levels. Extensive peroperative bleeding was encountered in two patients. One deep-wound infection was noted, postoperatively, and required surgical drainage, but no patients have been re-operated due to loosening of the instrument or to healing problems. In conclusion, the results of the present study indicate that the OC—and possibly other similar long-fixation systems that allow using both pedicle screws and lateral mass screws rigidly connected to a rod—is suited for treating subaxial cervical spine fractures in patients with ankylosing spondylitis, allowing high healing rates.     

颈椎小关节评估在改良型Stoke强直性脊柱炎脊柱评分体系中对评估强直性脊柱炎的影像学进展的研究

目的探讨颈椎小关节评估在改良型Stoke强直性脊柱炎脊柱评分体系(modified Stoke ankylosing spondylitis spine score,m SASSS)中对强直性脊柱炎患者(ankylosing spondylitis,AS)的影像学进展评估的临床诊断价值。方法收集了我院2010年1月-2014年12月期间收治的65例强直性脊柱炎患者。每个患者在随访前及随访过程中进行脊柱影像学检查,并根据m SASSS评分体系评估患者脊柱椎体的整体情况,以及增加针对颈椎小关节的影像学评估体系,通过计算两部分评分总和,即为我们定义的混合型改良脊柱评分(combined modified AS spine socre,cmASSS),并评价cmASSS评分体系的临床应用价值。结果在65例AS患者中,其中有58例完成的cmASSS评分。在随访前的影像学检查中通过cmASSS评分体系发现有69.0%的患者存在脊柱损伤的影像学改变,而m SASSS评分体系仅诊断50.0%的患者存在脊柱损伤(P=0.038)。随访观察期内通过影像学对疾病进展评估后发现,cmASSS评分体系中有60.3%的患者存在疾病进展,而m SASSS仅发现41.4%的患者存在疾病进展(P=0.041)。根据斯皮尔曼等级相关分析,cmASSS评分与AS患者的颈椎旋转、枕墙距、脊柱侧弯、胸廓扩张等脊柱活动度指标和AS功能指数的相关性优于m SASSS评分。结论在m SASSS基础上整合颈椎小关节评估有助于更全面、及时地诊断AS患者的脊柱损伤情况和脊柱损伤进展或转归,为AS的治疗、预后评估提供指导。     

强直性脊柱炎合并颈椎无骨折脱位型脊髓损伤

目的 总结强直性脊柱炎合并颈椎无骨折脱位型脊髓损伤的临床特征、诊断和手术治疗。方法 1986～2004年，笔者手术治疗累及颈椎的强直性脊柱炎合并无骨折脱位型脊髓损伤27例。结果 本组27例中椎管内韧带骨化18例，脊髓损伤的原因依次为韧带骨化所致的椎管狭窄，椎间盘损伤和椎体后骨刺及椎间不稳定。术前均为不完全性损伤，非手术治疗不提高脊髓功能。术后脊髓ASIA分级平均改善1级。后路手术椎板切除率、出血量、手术时间、术后引流量明显高于不合并强直性脊柱炎的患者。前路手术可达到骨性融合。结论 强直性脊柱炎合并颈椎无骨折脱位型脊髓损伤一般为不完全性损伤，损伤的内因依次为椎管内韧带骨化所致的椎管狭窄、椎间盘损伤、椎间骨赘和椎间不稳定。适当的手术可改善脊髓功能。手术难度大，风险高。     

强直性脊柱炎患者颈椎新鲜骨折的临床特征及术式选择

目的 :探讨强直性脊柱炎(AS)患者颈椎新鲜骨折的临床特征及手术策略。方法:回顾性分析2002年2月~2014年10月我科收治的15例AS颈椎新鲜骨折患者的临床资料,其中男14例,女1例,年龄36~76岁,平均49.7±10.8岁。13例有明确外伤史,其中4例为高能量损伤;经椎间隙和经椎体骨折分别为8例和7例,14例累及C5~C7节段;12例(80%)伴神经功能损害。12例接受手术治疗,7例前柱广泛破坏者行前路椎间盘切除或椎体次全切除、内固定植骨融合术;3例脊髓后方受压、前柱轴向承载功能保持良好的患者行后路椎板减压内固定融合术;2例严重骨折脱位不稳定患者行前后路联合手术。采用ASIA分级评估患者手术前后神经功能状态,摄颈椎X线片观察植骨融合情况。结果:除3例未手术患者外,余患者均获得随访,随访时间3~60个月(20.0±18.8个月),除1例术前ASIA A级及2例ASIA D级患者外,其余患者术后神经功能均获明显改善,末次随访时骨折部位骨性融合。围手术期并发症包括脑脊液漏1例,喉返神经损伤1例,前路术后切口深部感染1例。随访中无骨折不愈合、假关节形成及内固定失败。结论:AS颈椎新鲜骨折好发于下颈椎,伤后神经系统并发症发生率较高,应积极手术治疗稳定脊柱;前柱明显破坏患者选择单纯前路手术,前柱轴向承载功能尚可者行单纯后路手术,严重颈椎骨折脱位患者应行前后路联合手术。     

Corrective surgery for deformity of the upper cervical spine due to ankylosing spondylitis

Rotational and flexion deformity of C1-C2 due to ankylosing spondylitis is rare. We did surgical correction in one such case by lateral release, resection of the posterior arch of C1 and mobilization of the vertebral arteries, wedge osteotomy of the lateral masses of C1 and internal fixation under general anesthesia. There were no vascular and neurological complications during the surgery. After operation the atlantoaxial rotational deformity was corrected and the normal cervical lordosis was restored. At 1 year followup his visual field and feeding became normal and internal fixation was stable.     

Rheumatoid spondylitis

Summary (1) Two out of ten necropsy cases with rheumatoid arthritis had multiple erosive and destructive changes in the thoracic and lumbar vertebrae, in addition to the cervical vertebrae. (2) Apophyseal joints of the thoracic and lumbar vertebrae are often involved in rheumatoid arthritis. (3) The area of the enthesis and peridiscal connective tissue is most likely to be involved in rheumatoid arthritis and seems to be the site of the initial changes. (4) Early operative fusion may be useful in preventing the progression of the rheumatoid spondylitis.

---

Résumé (1) Deux autopsies sur dix, chez des malades présentant une arthrite rhumatoïde, ont montré des lésions multiples à type d'érosion et de destruction au niveau des vertèbres dorsales et lombaires, en plus de l'atteinte des vertèbres cervicales. (2) Les articulations interapophysaires des vertèbres dorsales et lombaires sont souvent lésées au cours de l'arthrite rhumatoïde. (3) Le tissu conjonctif péridiscal est le plus vraisemblablement atteint dans l'arthrite rhumatoïde et paraît être le lieu des modifications initiales. (4) La fusion chirurgicale précoce peut être utile pour arrêter la progression de la spondylite rhumatoïde.

     

ASKyphoplan: a program for deformity planning in ankylosing spondylitis

A closing wedge osteotomy of the lumbar spine may be considered to correct posture and spinal balance in progressive thoracolumbar kyphotic deformity caused by ankylosing spondylitis (AS). Adequate deformity planning is essential for reliable prediction of the effect of surgical correction of the spine on the sagittal balance and horizontal gaze of the patient. The effect of a spinal osteotomy on the horizontal gaze is equal to the osteotomy angle. However, the effect of a spinal osteotomy on the sagittal balance depends on both the correction angle and the level of osteotomy simultaneously. The relation between the correction angle, the level of osteotomy and the sagittal balance of the spine can be expressed by a mathematical equation. However, this mathematical equation is not easily used in daily practice. We present the computer program ASKyphoplan that analyses and visualizes the planning procedure for sagittal plane corrective osteotomies of the spine in AS. The relationship between the planned correction angle, level of osteotomy and sagittal balance are coupled into the program. The steps taken during an ASKyphoplan run are outlined, and the clinical application is discussed. The application of the program is illustrated by the analysis of the data from a patient recently treated by a lumbar osteotomy in AS. The software can be used free of charge on the internet at under the heading “research” in the menu.     

术前头环背心复位固定在颈椎骨折脱位合并强直性脊柱炎患者中的临床应用

目的：探讨颈椎骨折脱位合并强直性脊柱炎（AS）患者术前应用头环背心（Halo vest）复位固定的有效性及安全性。方法：回顾性分析2012年1月～2019年1月我院23例术前行头环背心复位固定的颈椎骨折脱位合并AS患者的临床资料,其中男性22例,女性1例,年龄39～64岁（53.0±7.4岁）。患者损伤平面C2/3 1例,C4/5 5例,C5/6 13例,C6/7 1例,跨椎节斜形骨折3例（C4-C5椎体2例,C5-C6椎体1例）。术后随访12～36个月,平均22.4±7.7个月。所有患者入院诊断明确后采用头环背心进行复位、固定,直至手术结束。固定前后行颈椎侧位X线片评估复位效果,记录术前术中有无骨折断端再脱位、继发性神经功能恶化。所有患者骨折复位后行单纯后路或者前后联合入路植骨融合内固定术,记录手术时间、出血量及相关并发症。术前及末次随访采用美国脊柱损伤协会（ASIA）分级标准评估患者神经功能情况,并记录椎体融合时间。结果：应用头环背心17例患者获得解剖复位,4例复位满意,2例复位失败,复位失败患者手术前全身麻醉状态下再次进行复位获得解剖复位。固定治疗期间患者均未出现骨折断端再脱位或...     

Management of Andersson lesions of spine: A systematic review of the existing literature

IntroductionAndersson lesions also termed as aseptic spondylodiscitis, spinal pseudoarthrosis are known to occur in patients with ankylosing spondylitis. Trauma as well as inflammation has been cited as factors responsible for the causation of these lesions. A variety of surgical approaches have been described in the literature such as anterior, posterior, combined anterior and posterior, with or without reconstruction of the anterior column defect. Controversy still exists regarding the optimal management these lesions.ObjectiveTo address the optimal method of management, levels of instrumentation, requirement of fusion and anterior instrumentation and general epidemiological profile of the patients with Andersson lesions.Materials and methodsAn electronic search for studies on the surgical management of Andersson lesions of spine was performed. Quality assessment of the included articles was done by two independent authors according to the criteria used by researchers previously in systematic reviews.ResultsMales were found to have an increased incidence with the thoracolumbar junction being the most common level. Posterior approach was the most favoured with reconstruction of the gap in the anterior column. Posterior osteotomy with correction of deformity was done commonly for an optimal healing environment. Instrumenting 2–3 levels above and below the lesion is favoured by most.ConclusionConservative management for Andersson lesions can be employed in the setting of acute trauma and stable fractures involving a single column. Surgical management of these lesions with a posterior long segment fixation and anterior column reconstruction is the favoured treatment in majority of the cases.     

强直性脊柱炎颈椎骨折诊断及后路内固定治疗

目的:探讨强直性脊柱炎颈椎骨折的临床特点,并应用后路侧块钢板内固定治疗强直性脊柱炎颈椎骨折。方法:对本院收治的14例强直性脊柱炎颈椎骨折病人行颈椎后路减压侧块内固定术,并根据住院资料及出院后随访,进行回顾性分析,总结其临床特点,观察神经功能恢复、骨折愈合及并发症情况。结果:强直性脊柱炎颈椎骨折病人约占所有颈椎骨折病人的3.5％,AS病史平均23年,好发于C_(6～7),其次为C_(5～6)。后路减压侧块固定操作简单,经术后平均23个月随访无神经功能恶化,Frankel分级较术前平均改善1级,骨折愈合良好,愈合时间平均3.5个月,并发症少。结论:强直性脊柱炎颈椎骨折好发于下颈椎椎间隙,容易漏诊迟诊,全面的影像学检查是诊断关键。受伤外力较小,脊髓损伤的发生率较高,后路减压侧块钢板内固定术治疗是一种有效的治疗方法。     

Transpedicular closed wedge osteotomy in ankylosing spondylitis: results of surgical treatment and prospective outcome analysis

Abstract  

Surgery in late stage ankylosing spondylitis (AS) most often tends to correct the sagittal balance with an extension osteotomy of the spine. In the literature, extension osteotomy was first described as an open wedge osteotomy but recently closed wedge osteotomy resecting the pedicles and posterior elements have become more popular. Only a limited number of cases have been reported in the literature and with limited focus on outcome of this major surgery. In this study, we reported the results of a large series of extension osteotomy in a population of patients with AS focusing on the technical aspects, complication rates, correction obtained and outcome evaluation using newer spine outcome measuring instruments. In the period from 1995 to 2005, 36 consecutive patients fulfilled the criteria where the files, radiographs and patients were available for further studies. The following data were recorded: Age, sex, comorbidity, indication, operation time and blood loss, level of osteotomy and estimated Correction. Furthermore, perioperative complications and all late complications were registered. The average follow-up was 50 months (3–128). Twenty-one patients also filled out questionnaires (SF36 and Oswestry Disability Index) preoperatively. At the end of the period all patients were contacted and filled out the same questionnaires. Fifteen of the patients had two pedicular resection osteotomies performed, 21 had one, and two had polysegmental osteotomies. Mean operation time was 180 min, bleeding was mean 2,450 ml, stay at the hospital was 13 days. One patient had partial paresis of the lower extremities all other complications were minor. The median correction was 45°. The median Oswestry score improved significantly from 54 (range 20–94) preoperatively to 38 (range 2–94) postoperatively. The SF-36 score significantly increased, when evaluated on the major components Physical Component Summary (PCS) and Mental Component Summary (MCS). The thoracolumbar closed wedge pedicular resection osteotomy used in this series was a safe method for correction of incapacitating kyphosis in AS. There was an acceptable rate of perioperative complications and no mortality. The correction obtained was in average 45°. All of the patients except one maintained their good correction and restored function. Outcome analysis showed a significant improvement in SF-36 and Oswestry Disability Index, and the mental component of the SF-36 showed improvement to values near the normative population. It is concluded that corrective osteotomy of the thoracolumbar spine in AS is an effective and safe treatment with improvements in quality of life.     

Two-level pedicle subtraction osteotomy for severe thoracolumbar kyphotic deformity in ankylosing spondylitis

Study design

A retrospective clinical study.

Objective

To evaluate the outcomes of two-level (T12 and L3) pedicle subtraction osteotomy (PSO) for severe thoracolumbar kyphosis in ankylosing spondylitis (AS), and to discuss the surgical strategies of this surgery.

Background

Cases were limited on the results of two-level PSO for correction of severe kyphosis caused by AS, nor on surgical strategies of this type of surgery.

Methods

From March 2006 to December 2010, nine consecutive AS patients with severe kyphotic deformity, underwent T12 and L3 PSOs. Chin-brow vertical angle (CBVA) and radiographic assessments which contain thoracic kyphosis (TK), lumbar lordosis (LL), global kyphosis (GK), and sagittal vertical axis were carefully recorded pre and postoperatively to evaluate the sagittal balance. Intra and postoperative complications were also registered. All patients were asked to fill out Oswestry Disability Index before surgery and at the last follow-up visit.

Results

All nine patients (8M/1F), averaged 41.4 years old (range 35–51 years), were received two-level (T12 and L3) PSO, and were followed up after surgery for a mean of 39.9 months (range 24–68 months). Good cosmetic results were achieved in all patients. Mean correction at two-level PSO was 67.9 ± 5.5°. All CBVA, TK, LL, and GK were changed significantly after surgery (P < 0.05), the mean amount of correction of which were 59.5 ± 13.8, 34.7 ± 3.8, 33.2 ± 2.4, and 54.0 ± 14.8 degrees, respectively, and with a small loss of correction at the last follow-up visit. Sagittal imbalance was significantly improved from 27.3 ± 4.4 to 3.4 ± 0.7 cm postoperatively. Neither mortalities nor any major neurological complications were found. The mean ODI score was significantly improved from 53.4 ± 15.5 before surgery to 8.2 ± 4.7 at the last visit.

Conclusion

The outcomes of follow-up showed that two-level (T12 and L3) PSO can effectively and safely correct severe thoracolumbar kyphosis in AS.