Vertebral fractures in late adolescence: a 27 to 47-year follow-up

The long-term outcome of thoracic and lumbar fractures in late adolescence is sparsely described and it is unclear whether a fractured vertebral body in these years, as in young children, can be resituated in height. The purpose of this study was to in late adolescence determine the incidence, the long-term outcome and the modelling capacity in fractures of the thoracic and lumbar region. The incidence of vertebral fractures 1950–1971 in individuals aged 16–18 years was through the radiological archives evaluated in a city cohort of 228,878 citizens, of whom 13,893 were aged 16–18. A follow-up, 27–47 years after the injury, including subjective, objective and radiological evaluation was conducted in 18 boys and 5 girls. Twenty-nine boys and 11 girls were registered with a thoracic or lumbar vertebral fracture during the study period conferring an annual incidence of 0.14‰. Of the 23 individuals that attended the follow-up, 14 had one-column compression fractures, one a Denis type A, six a Denis type B, one a Denis type D and one a Chance fracture. At injury, one had a partial paresis in one leg and one developed a transient paraparesis during the first week. All were treated non-operatively. At follow-up, 18 individuals had no complaints while 5 had occasional back pain, 20 were classified as Frankel E and 3 as Frankel D. The radiographic ratio of anterior height to posterior height of the fractured vertebral body was unchanged during the study period. Thoracic and lumbar vertebral fractures in late adolescence with no or minor neurological deficits have a predominantly favourable long-term outcome, even if no modelling capacity of the fractured vertebral body remains in late adolescence.     

前路骨折椎体后上角切除椎管减压单节段固定融合治疗腰椎爆裂骨折的初期临床结果

目的报道骨折椎体后上角部分切除减压、前路单节段固定融合治疗腰椎爆裂骨折的手术方法和早期临床结果。方法2006年6月～10月,收治4例Denis B型腰椎爆裂性骨折患者,采用骨折椎体后上角部分切除减压、前路单节段固定融合治疗。其中男2例,女2例;年龄17～39岁。均为高处坠落伤,伤后10～12d手术。骨折平面位于L1和L2各2例。术前神经功能评价采用Frankel评分,B、C级各2例,视觉模拟疼痛量表（visual analogue scale,VAS）评分7.00±0.82。影像学评价：X线侧位片测量患者后突畸形的Cobb角为22.94±11.21°;邻近融合节段上下椎间盘高度,分别为上位12.78±1.52mm,下位11.68±1.04mm;CT扫描测量椎管矢状直径为9.56±2.27mm。于术后即刻、术后3个月再次对患者进行神经功能和影像学评价。结果4例前路单节段加压融合固定手术顺利,手术时间平均为166±29min,术中出血量平均为395±54ml。Frankel评分,术后即刻,2例术前B级有1例恢复至C级,1例不变;2例术前C级有1例恢复至D级,1例不变;术后3个月,2例术前B级均恢复至C级,1例C级恢复至D级,另1例C级恢复至E级。VAS评分于术后即刻显著下降至3.50±1.29;术后3个月为1.25±0.50,分别与术前比较差异有统计学意义（P〈0.05）。术后即刻椎管矢状直径较术前扩大至19.76±3.82mm（P〈0.01）;术后3个月为19.27±3.41mm,与术后即刻比较差异无统计学意义（P〉0.05）。术后即刻Cobb角为8.71±5.41°（P〈0.05）;术后3个月为9.52±5.66°,与术后即刻比较差异无统计学意义（P〉0.05）。术后即刻的邻近融合节段上下椎间盘高度分别为10.97±1.44mm和11.65±1.47mm,术后3个月时分别为10.93±1.46mm和11.34±1.45mm,各时间点比较差异均无统计学意义（P〉0.05）。术后即刻及术后3个月内随访患者恢复良好,未出现并发症。术后3个月X线片及CT扫描示内固定位置良好,未发现内固定物松动移位的表现。结论前路单节段减压固定融合技术对于Denis B型骨折能达到脊髓减压的目的,术后早期能够保持脊柱的稳定,但远期效果仍需要进一步随访和观察。     

经椎旁肌间隙入路在胸腰椎骨折治疗中的应用

 目的 探讨经椎旁肌间隙入路治疗胸腰椎骨折的手术方法及其与传统手术方法的比较。方法 2006年 10月至 2008年 10月, 52例无神经损伤表现的胸腰椎骨折患者被纳入研究。±据 Denis骨折分型, 压缩型骨折 17例, 爆裂型骨折 35例, 其中男 37例, 女 15例;年龄 18耀59岁, 平均 46.5岁。 T4骨折 1例, T7骨折 2例, T8骨折 1例, T10骨折 3例, T11骨折 5例, T12骨折 14例, L1骨折 16例, L2骨折 9例, L3骨折 1例。影像学检查示: 椎管内占位约1/3, 突入椎管骨块均匀完整, 无碎裂及翻转。患者±次纳入研究, 分为两组, 其中 20例患者采用传统后正中入路, 其他 32例患者采用经椎旁肌间隙入路, 均行后路椎弓根螺钉固定。结果两组患者在性别、年龄、损伤节段、受伤至手术时间及随访时间方面比较, 差异均无统计学意义。经肌间隙入路较传统后正中入路在手术时间、术中出血量、引流放置时间、术后引流量、术后下地时间, 疼痛视觉模拟评分及 Oswestry功能障碍指数等方面具有显著优势, 两组间比较各项指标差异均有统计学意义。至 2009年 10月, 所有患者均获得随访, 平均时间 21.5个月(12耀36个月), 所有患者伤椎椎体高度均无丢失, 内固定无松动、断裂。结论与传统手术方法相比, 经椎旁肌间隙入路治疗胸腰椎骨折可完整保留脊柱后方复合体结构, 具有创伤小、出血少和恢复快等优点, 是一种安全实用的手术方法, 疗效满意。     

压缩性脊椎骨折各节段形态学变化特点的探讨

目的 探讨压缩性脊椎骨折各节段形态学变化特点。方法 对412例共448处楔形和爆裂骨折各节段形态学变化进行分析,比较楔形骨折和爆裂骨折各节段的发生概率,计算各节段楔形骨折椎体前缘压缩比学较大。腰椎,尤其上腰椎,发生爆裂骨折的概率较高,即使发生楔形骨折,其椎体前缘压缩率相对胸椎而言常较小。结论 脊椎骨折类型或形态学变化除与暴力、受伤瞬间体位相关外,与骨折发生部位也存在一定关系。     

Outcome of thoracolumbar burst fractures treated with indirect reduction and fixation without fusion

Indirect reduction and fixation is not a new method in the treatment of thoracolumbar burst fractures but the indications and efficacy are controversial. The current study was designed to evaluate the efficacy of indirect reduction without fusion. Sixty-four patients with single-level thoracolumbar burst fractures were identified and treated by this method. The outcome was analyzed by the Frankel method, radiographic measurements, and at the latest follow-up the Denis Pain Scale and Oswestry disability index (ODI) were used to assess back pain and functional outcome. The average follow-up period was 40.1 months. The anterior vertebral height (AVH) was corrected from 55.2 to 97.2% post-operatively and decreased to 88.9% after hardware removal. The posterior vertebral height (PVH) increased from 88.9 to 99.1% post-operatively and decreased slightly after implant removal to 93.7%. The average pre-operative canal compromise was 41.4%, which decreased to 13.7% at last follow-up. Except for three paraplegic patients, neurological status significantly improved or stayed normal in the study’s remaining 61 patients. Fifty-two of sixty-four patients had excellent or good function. At latest follow-up the average ODI score was 16.7 and the Denis pain score improved in all patients but one. Indirect reduction and fixation can not only restore vertebral column structure but also, more importantly, patients’ functional outcome.     

经椎弓根硬膜前方减压治疗胸腰椎爆裂性骨折

目的探讨一种治疗胸腰椎爆裂性骨折的有效方法。方法2004年5月~2006年1月,行经椎弓根硬膜前方减压植骨治疗20例胸腰椎爆裂性骨折。其中,男13例、女7例;年龄为30~65岁,平均42.3岁。按照AO脊柱骨折分类:A318例、B21例、C21例。Frankel分级:A级4例、B级6例、C级5例、D级3例、E级2例。均行半椎板切除,经椎弓根硬膜前方减压植骨,辅以未减压侧后外侧植骨,全部加用椎弓根钉内固定。对后凸畸形的矫正、病椎压缩程度的恢复、脊髓神经功能的康复进行评估,观察融合情况。结果20例患者均获得随访,随访时间为6~15个月,平均8.3月。Frankel分级:A级2例、B级4例、C级5例、D级5例、E级4例。术后摄片示椎管减压充分,后凸畸形完全纠正。3个月后植骨明显融合,术后6月Cobb角丢失4°~9°,平均7.3°。结论在严格的掌握适应症的前提下,经椎弓根硬膜前方减压是一种安全有效的胸腰椎爆裂性骨折治疗方法。     

Complete rotational burst fracture of the third lumbar vertebra managed by posterior surgery. A case report

STUDY DESIGN: Case report of a young man with rotational burst fracture of the third lumbar vertebra, treated by posterior surgery. OBJECTIVES: To describe the management of a rotational burst fracture of the third lumbar vertebra by posterior surgery consisting of reduction, decompression, fusion, and transpedicular instrumentation. SUMMARY OF BACKGROUND DATA: Surgery is the generally recommended means of managing lumbar burst fractures with neurologic deficit. Some surgeons recommend anterior decompression, fusion, and instrumentation. Posterior surgery with decompression through laminectomy, spongioplasty of the vertebral body, interbody fusion of damaged discs, posterolateral fusion, and transpedicular fixation is also a safe and successful management technique. The combined approach consists of posterior decompression, fusion, transpedicular fixation, and anterior fusion using pelvic autografts. The optimum method of management remains in question. METHOD: An 18-year-old man with complete rotational burst fracture of the third lumbar vertebra was treated by posterior surgery. This surgery consisted of reduction, laminectomy, decompression, structure of dural sac tears, spongioplasty of the vertebral body, interbody fusion of both damaged discs, and the implantation of a transpedicular Socon fixator (Aesculap, Tuttlingen, Germany), including a transverse connector. The case was documented by radiographs and computed tomography scans before surgery and after fixator removal 19 months after surgery. RESULTS: The patient healed solidly with no instrumentation failure. The neurologic deficit Frankel Grade B improved to Frankel Grade D. CONCLUSION: Surgery to manage lumbar burst fracture must include reduction, decompression, restoration and fusion of anterior and posterior elements by using autologous pelvic spongious autografts, and anterior or posterior instrumentation. Posterior surgery including suturing of dural sac tears, fusion of damaged structures, and transpedicular fixation is successful in young patients and patients with good bone quality.     

Neurological deficit and canal compromise in thoracolumbar and lumbar burst fractures

PURPOSE: To assess whether canal compromise determines neurological deficit in thoracolumbar and lumbar burst fractures. METHODS: 105 patients aged 17 to 60 (mean, 34) years who had burst fractures in the thoracolumbar (n=82) and lumbar (n=23) regions were included. Fractures were classified according to the Denis classification. The extent of spinal canal compromise was assessed by computed tomography, and the neurological status according to the modified Frankel grading for traumatic paraplegia. RESULTS: 19 (18%) of the patients had no neurological deficit. Of the remaining 86 (82%) with a deficit, 26 had complete paraplegia. The correlation between the type of the burst fracture and the severity of neurological deficit was not significant (Chi squared=10.57, p=0.835). The mean extent of spinal canal compromise in patients with deficits was 50%, whereas in patients with no deficit it was 36%. The difference between the extent of canal compromise and the severity of neurological deficit at the thoracolumbar and lumbar spine was not significant (p=0.08). Further subanalysis revealed a significant correlation at T11 and T12 (p=0.007) but not at the L1 (p=0.42) level. CONCLUSION: When studying neurological deficit, T11 and T12 injuries should be analysed separately from L1 injuries.     

后路伤椎植骨内固定加椎管成形治疗胸腰椎严重爆裂性骨折

目的:探讨后路经椎弓根通道椎体内植骨椎弓根螺钉内固定加自体髂骨移植椎管成形治疗严重胸腰椎爆裂性骨折的临床疗效.方法:自2004年3月至2008年3月,应用后路经椎弓根通道椎体内植骨椎弓根螺钉内固定加保留棘突全椎板减压自体髂骨椎管重建治疗胸腰椎严重爆裂性骨折患者10例,男7例,女3例;年龄24～58岁,平均41岁.术后通过Frankel分级与影像学检查评价手术疗效.结果:10例患者均获随访,时间1～4年,平均37个月.椎弓根螺钉无松动,无断钉、断棒,伤椎椎体前缘高度从术前(21.00±12.00)%恢复至术后(95.00±4.20)%,后缘高度从术前(70.00±15.00)%恢复至术后(96.00±3.20)%,差异有统计学意义(P＜0.01).Cobb角从术前(32.80±8.20)°恢复至术后(4.20±1.60)°,差异有统计学意义(P＜0.01).Frankel分级除1例A级者外,其余均有1级以上改善.腰痛按Denis分级评估:P1 4例,P2 4例,P3 1例,P4 1例.结论:采用后路经椎弓根通道椎体内植骨椎弓根螺钉内固定加自体髂骨椎管成形是治疗严重胸腰椎爆裂性骨折的有效方法,具有操作简单,疗效好,保留后柱结构等优点,值得临床推广使用.     

Mono segmental fixation of selected types of thoracic and lumbar fractures; a prospective study

Aim of study

A prospective study to evaluate the results of monosegmental fixation; fixation of the fractured level with the adjacent vertebra sharing the same disc, in selected types of lumbar and thoracic fractures. This technique aims at saving motion levels by fusion of the only affected motion segment without sacrificing other levels.

Methods

Forty patients enrolled in this study between August 2011 and October 2013. The inclusion criteria were recent thoracic or lumbar vertebral fractures (less than 2 weeks). The fracture involves only one of the end plates of the vertebrae (either the superior or the inferior). The other end plate and both pedicles should be intact. The exclusion criteria were cervical fractures, fractures that include both end plates or pedicles of the vertebra, fracture dislocation, and load sharing classification score more than seven. All patients underwent monosegmental fixation with pedicle screw fixation. Eight patients were supplemented with interbody grafts. Radiological evaluation was done to assess local kyphosis angle, degree of compression of the anterior column, the degree of comminution, retropulsed fragment, neural canal compromise, integrity of the affected end plate, exclusion of pedicle fracture, and most important to assure that only one end plate is affected. All patients were assessed neurologically according to Frankel grading system. Patient were assessed by Denis pain scale and Denis work scale.

Results

The age of the patients was of a mean of 34.5 years old. All patients were Frankle E at time of presentation and remained the same post-operative. The mean operative time from incision time to end of skin closure was 74.2 min. The mean blood loss was 230 ml. The pre-operative degree of local kyphosis; was of a mean 8.22°. This was improved to 2.25° at the immediate postoperative x-rays. At two years follow up, the loss of correction was of a mean 0.85° which was insignificant. The pre-operative percentage of height lost improved from a mean of 56.05 % to post-operative mean of 90.125 %. At the end of follow up, no pseudoarthrosis cases or metal failure were noticed.

Discussion

Thoracic and lumbar fractures are common in young adults. Surgical treatment offers early rehabilitation and preserves spine alignment. Monosegmental fixation technique in selected types of dorsal and lumbar fractures offers spine stability and preserves motion segments. It fuses only one motion segment that is prone for later instability or deformity. Reconstrcution of the anterior column can be achieved through TLIF approach in combination of monosegmental fixation to achieve 360° fusion.

Conclusion

Monosegmental fixation is an effective technique. It can save motion segments in young patients with adequate spine stability and good functional outcomes.

     

Long‐term results of thoracolumbar and lumbar burst fractures after short‐segment pedicle instrumentation,with special reference to implant failure and correction loss

Objective: To assess the long‐term results of short‐segment pedicle instrumentation for thoracolumbar and lumbar burst fractures. Methods: From February 1987 to June 1995, 89 patients with thoracolumbar or lumbar burst fracture were treated with short‐segment pedicle instrumentation, and 68 (76.4%) of them were followed up for an average of 8.0 years (range, 5–13 years). Radiographs were taken pre‐ and post‐ operatively, before implant removal and at final follow‐up. Computerized tomography (CT) scans of the fractured vertebrae were done on 18 patients, with their consent, at final follow‐up. Results: At final follow‐up, neurological status had improved at least one grade in the Frankel Grading system in 90.8% patients who had presented incomplete paralysis preoperatively, and low back pain was evaluated as Denis' P₁ in 60.3%, P₂ in 35.3% and P₃ in 4.4% of patients. An average of 2.5 mm (range, 0–6.5 mm) of implant deformation was recorded before implant removal, and implant failure was noted in 11 (16.2%) patients. At final follow‐up, loss of correction of the anterior vertebral body height and Cobb angle averaged 1.9% and 12.1°, leaving residual correction rates of 30.5% and 5.8°, respectively. The loss of correction occurred mainly at adjacent disc spaces, and collapse of the vertebral body was more severe at its center. CT scan revealed an obvious gap, which communicated with the adjacent disc space, in the vertebral body of 16 of the 18 patients scanned. Local kyphosis of more than 20° existed in five patients and three of them had low back pain. Conclusion: Short‐segment pedicle instrumentation provides satisfactory reduction for thoracolumbar and lumbar burst fractures. The relatively high incidence of implant failure and the loss of correction may be caused by various factors, and more adequate fusion is recommended.     

More than 5-Year Follow-up Results of Two-Level and Three-Level Posterior Fixations of Thoracolumbar Burst Fractures with Load-Sharing Scores of Seven and Eight Points

Background

The development of pedicle screw-based posterior spinal instrumentation is recognized as one of the major surgical treatment methods for thoracolumbar burst fractures. However, the appropriate level in posterior segment instrumentation is still a point of debate. To assesses the long-term results of two-level and three-level posterior fixations of thoracolumbar burst fractures that have load-sharing scores of 7 and 8 points.

Methods

From January 1998 to May 2009, we retrospectively analyzed clinical and radiologic outcomes of 45 patients with thoracolumbar burst fractures of 7 and 8 points in load-sharing classification who were operated on using two-level posterior fixation (one segment above and one segment below: 28 patients, group I) or three-level posterior fixation (two segments above and one segment below: 17 patients, group II). Clinical results included the grade of the fracture using the Frankel classification, and the visual analog score was used to evaluate pain before surgery, immediately after surgery, and during follow-up period. We also evaluated pain and work status at the final follow-up using the Denis pain scale.

Results

In all cases, non-union or loosening of implants was not observed. There were two screw breakages in two-level posterior fixation group, but bony union was obtained at the final follow-up. There were no significant differences in loss of anterior vertebral body height, correction loss, or change in adjacent discs. Also, in clinical evaluation, there was no significant difference in the neurological deficit of any patient during the follow-up period.

Conclusions

In our study, two-level posterior fixation could be used successfully in selected cases of thoracolumbar burst fractures of 7 and 8 points in the load-sharing classification.     

Health-related quality of life after short segment instrumentation of lumbar burst fractures

Management of lumbar burst fractures remains controversial. Surgical reduction/stabilization is becoming more popular; however, the functional impact of operative intervention is not clear. The purpose of this study was to assess health-related quality of life and functional outcome after posterior fixation of lumbar burst fractures with either posterolateral or intrabody bone grafting. Twenty-four subjects were included. Radiographs and computed tomography scans were evaluated for deformity (kyphosis, vertebral compression, lateral angulation, lateral body height, and canal compromise) postoperatively, at 1 year, and at final follow-up (mean 3.2 years). Patients completed the SF 36 Health Survey and the Oswestry Low Back Pain Disability Questionnaire at final follow-up. Significant improvement was noted in midsagittal diameter compromise, vertebral compression, and kyphosis. The difference observed between the respondents mean scores on the SF 36 was not significantly different from those presented as the U.S. national average (p = 0.053). Data from the Oswestry questionnaire indicated a similarly high level of function. Overall, we found posterior spinal instrumentation to correlate with positive functional outcome based on both general health (SF 36) and joint-specific outcome scales (Oswestry). Posterior instrumentation provides sound canal decompression, kyphotic reduction, and maintains vertebral height with minimal transgression and long-term sequelae. In cases of severe initial deformity and neurologic compromise, intrabody bone grafting is most certainly indicated; the additional support provided by a posterolateral graft may also prove beneficial as an adjunct.     

椎弓根钉系统联合椎体内混合植骨治疗严重胸腰椎压缩、爆裂性骨折

目的探讨采用椎弓根钉系统复位固定联合经椎弓根椎体内骨泥、颗粒骨混合植骨治疗严重胸腰椎压缩、爆裂性骨折的疗效。方法2001年1月-2008年1月对18例严重新鲜胸腰椎骨折先行滑脱、骨折内固定器系统（SF或AF）固定,后经椎弓根向复位椎体内植入自体骨泥、颗粒骨。结果术中无脊髓、神经损伤等并发症,术中出血量50-300 ml,平均80 ml。手术时间100-180 min,平均120 min。术后住院时间12-30 d,平均14 d。18例随访5-72个月,平均24个月,椎体高度和生理弧度恢复满意,无神经症状加重,17例椎体高度和生理弧度无丢失,1例生理弧度部分丢失,无固定松动、断裂。术前脊髓损伤Frankel分级：A级1例,B级1例,C级5例,D级3例,E级8例;术后恢复至B级1例,C级1例,E级16例。结论椎弓根钉系统内固定联合经椎弓根椎体内骨泥、颗粒骨混合植骨治疗严重胸腰椎压缩、爆裂性骨折,手术安全,效果满意。     

Indirect spinal canal decompression in patients with thoracolumbar burst fractures treated by posterior distraction rods.

The ability of posterior distraction instrumentation to produce indirect reduction of retropulsed bone fragments was studied in 44 patients with thoracolumbar burst fractures. Using the Denis Classification, two predominate fracture types were identified: 13 patients had type A and 29 had type B fractures. Two others had Denis type D fractures. Spinal canal stenosis was reduced from a preoperative mean of 65% to 32.8% postoperatively. Denis type A fractures had significantly better reduction of 62.5% pre- to 19.2% postoperatively. Denis type B fractures reduced from 66.3% pre- to 38.9% postoperatively. The initial kyphotic deformity and the loss of vertebral height did not influence results of indirect decompression. Neurologic function at follow-up correlated with preoperative canal stenosis, but did not correlate with residual stenosis after instrumentation. This study demonstrated that posterior distraction instrumentation can achieve approximately 50% reduction in canal stenosis and that results will be influenced by fracture morphology.     

两种常用胸腰椎骨折分类系统的临床价值

目的探讨Denis和Gertzbein分类系统在胸腰椎骨折中的临床应用价值。方法40例急性胸腰椎骨折的X线片和CT提供给10位骨科医生,用Denis和Gertzbein两种分类方法进行分类。3个月后再分类。用Kappa(k)指数评价观察者间和观察者内的可信度。结果Denis四类型观察者间的平均Kappa(k)指数为0·588,16亚型为0·342;Gertzbein三类型为0·603,9亚型为0·420。Denis四类型观察者内的平均Kappa(k)指数为0·706,16个亚型为0·432;Gertzbein三类型为0·746,9亚型为0·511。结论Denis和Gertzbein分类系统都只呈中等程度的相符性和可重复性,都存在不同程度的缺陷。     

Instrumented ligamentotaxis and stabilization of compression and burst fractures of dorsolumbar and mid-lumbar spines

Background:

Controversy continues regarding the best treatment for compression and burst fractures. The axial distraction reduction utilizing the technique employing the long straight rod or curved short rod without derotation to reduce fracture are practised together with short segment posterolateral fusion (PLF). Effects of the early postoperative mobilization without posterolateral fusion on reduction maintenance and fracture consolidation were not evaluated so far. The present prospective study is designed to assess the effectiveness of i) reduction and restoration of sagittal alignment, ii) no posterolateral fusion on the reduced, fractured vertebral body and injured disc, iii) fracture consolidation and iv) the fate of the unfused cephalad and caudal injured motion segments of the fractured vertebra.

Materials and Methods:

The study includes 15 Denis burst and two Denis type D compression fractures between T₁₂ and L₃. The lordotic distraction technique was used for ligamentotaxis utilizing the contoured short rods and pedicle screw fixator. Three vertebrae including the fractured one were fixed. The patients after surgery were braced for ten weeks with activity restriction for 2-4 weeks. The patients were evaluated for change in vertebral body height, sagittal curve, reduction of retropulsion, improvement in neural deficit. The unfused motion segments, residual postoperative pain and bone and metal failure were also evaluated.

Results:

The preoperative and postreduction percentile vertebral heights at, zero (immediate postoperative), at three, six and 12 months followup were 62.4, 94.8, 94.6, 94.5 and 94.5%, respectively. The percentages of the intracanal fragment retropulsion at preoperative, and postoperative at zero, 3, 6 and 12 months followup were 59.0, 36.2,, 36.0, 32.3, and 13.6% respectively.The preoperative and postreduction percentile loss of the canal dimension and at zero, three, six and 12 months were 52.1, 45.0, 44.0, 41.0 and 29% respectively suggesting that the under-reduced fragment was being resorbed gradually by a remodeling process. The mean initial kyphosis of 33° became mean 2° immediately after reduction and mean 3° at the final followup. The fractured vertebral bodies consolidated in an average period of ten weeks (range 8-14 weeks). The restored disc heights were relatively well maintained throughout the observation period. All paraparetic patients recovered neurologically. There were no postoperative complications.

Conclusion:

Instrument-aided ligamentotaxis for compression and burst fractures utilizing the short contoured rod derotation technique and the instrumented stabilization of the fractured spine are found to be effective procedures which contribute to the fractured vertebral body consolidation without recollapse and maintain the motion segment function.     

Altered disc pressure profile after an osteoporotic vertebral fracture is a risk factor for adjacent vertebral body fracture

This study investigated the effect of endplate deformity after an osteoporotic vertebral fracture in increasing the risk for adjacent vertebral fractures. Eight human lower thoracic or thoracolumbar specimens, each consisting of five vertebrae were used. To selectively fracture one of the endplates of the middle VB of each specimen a void was created under the target endplate and the specimen was flexed and compressed until failure. The fractured vertebra was subjected to spinal extension under 150 N preload that restored the anterior wall height and vertebral kyphosis, while the fractured endplate remained significantly depressed. The VB was filled with cement to stabilize the fracture, after complete evacuation of its trabecular content to ensure similar cement distribution under both the endplates. Specimens were tested in flexion-extension under 400 N preload while pressure in the discs and strain at the anterior wall of the adjacent vertebrae were recorded. Disc pressure in the intact specimens increased during flexion by 26 ± 14%. After cementation, disc pressure increased during flexion by 15 ± 11% in the discs with un-fractured endplates, while decreased by 19 ± 26.7% in the discs with the fractured endplates. During flexion, the compressive strain at the anterior wall of the vertebra next to the fractured endplate increased by 94 ± 23% compared to intact status (p < 0.05), while it did not significantly change at the vertebra next to the un-fractured endplate (18.2 ± 7.1%, p > 0.05). Subsequent flexion with compression to failure resulted in adjacent fracture close to the fractured endplate in six specimens and in a non-adjacent fracture in one specimen, while one specimen had no adjacent fractures. Depression of the fractured endplate alters the pressure profile of the damaged disc resulting in increased compressive loading of the anterior wall of adjacent vertebra that predisposes it to wedge fracture. This data suggests that correction of endplate deformity may play a role in reducing the risk of adjacent fractures.     

Change in vertebral shape in spinal osteoporosis

Summary The change in vertebral shape with increasing severity of spinal osteoporosis was studied in 139 women with atraumatic spinal fractures. The anterior height was below the normal range in 570 vertebrae, and the posterior height was below normal in 157 vertebrae. All values below the normal range were defined as fractures. Ninety-eight percent of posterior fractures were associated with anterior fractures. The fractures involved both the anterior and posterior vertebral borders in 58/356 (17%) of the fractured vertebrae in patients with 6 or less fractures, compared with 93/217 (45%) of the fractured vertebrae in patients with 7 or more fractures. The distribution of anterior fractures was biphasic with peak frequencies at T7–T8 and T11–T12. Posterior fractures had a more lumbar distribution, perhaps resulting from higher compressive forces on the posterior vertebral border of the lordotic lumbar spine than on the kyphotic thoracic spine. The mean anterior and posterior height of nonfractured vertebrae in osteoporotics was not significantly different from normal, suggesting that osteoporotics do not have smaller vertebrae than normal subjects.     

Low thoracic and lumbar burst fractures: radiographic and functional outcomes

Twenty patients with thoracolumbar burst fractures (type A3 in the classification of Magerl et al.) were studied prospectively for the evaluation of clinical, radiographic and functional results. The patients were submitted to surgical treatment by posterior arthrodesis, posterior fixation and autologous transpedicular graft. The patients were followed up for 2 years after surgery and assessed on the basis of clinical (pain, neurologic deficit, postoperative infection), radiographic (load sharing classification, Farcy s sagittal index of the fractured segment, relation between traumatic vertebral body height and the adjacent vertebrae (compression percentage), height of the intervertebral disk proximal and distal to the fractured vertebra, rupture or loosening of the implants) and functional (return to work, SF-36) criteria. Two patients presented a marked loss of correction and required the placement of an anterior support graft. Pain assessment revealed that eight patients (44%) had no pain; four (22%) had occasional pain, three (17%) moderate pain, and three (17%) severe pain. According to the classification of Frankel et al., 17 patients persisted as Frankel E and one patient presented improvement of one degree, becoming Frankel D. The mean value of Farcy s sagittal index of the injured vertebral segment was 20.67 degrees +/- 6.15 degrees (range 8 degrees -32 degrees ) during the preoperative period, 11.22 degrees +/- 8.09 degrees (range -5 degrees to 21 degrees ) during the immediate postoperative period, and 14.22 degrees +/- 7.37 degrees (range 3 degrees -25 degrees ) at late evaluation. There was a statistically significant difference between the immediate postoperative values and the preoperative and late postoperative values. The compression percentage of the fractured vertebral body ranged from 9.1 to 60 (mean 28.81 +/- 11.51) during the preoperative period, from 0 to 60 (mean: 15.59 +/- 14.49) during the immediate postoperative period, and from 8 to 60 (mean: 25.9 +/- 13.02) at late evaluation. There was a statistically significant difference between the preoperative and postoperative values and between the postoperative and late postoperative values. The height of the proximal intervertebral disk ranged from 6 to 14 mm (mean 8.44 +/- 2.66) during the preoperative period, from 6 to 15 mm (mean 10 +/- 2.30) during the immediate postoperative period, and from 0 to 11 mm (mean 7.22 +/- 2.55) during the late postoperative period. A significant difference was observed between the immediate postoperative values and the preoperative and late postoperative values. The height of the intervertebral disk distal to the fractured vertebra ranged from 7 to 16 mm (mean 9.94 +/- 2.64) during the preoperative period, from 5 to 18 mm (mean 11.61 +/- 3.29) during the immediate postoperative period, and from 2 to 14 mm (mean 9.72 +/- 3.17) during the late postoperative period. There was a significant difference between the immediate postoperative values and the preoperative and late postoperative values. Except for the height of the intervertebral disk proximal to the fractured vertebra, no correlation was detected between the clinical, functional and radiologic results. The results observed in the present study indicate that other, still incompletely defined parameters influence the functional result of thoracolumbar burst fractures.