Use of vertebroplasty to prevent proximal junctional fractures in adult deformity surgery: a biomechanical cadaveric study

Background contextVertebral compression fractures at the proximal junction are common complications of long spinal fusion surgeries that can contribute to the development of proximal junctional kyphosis or proximal junctional failure. To our knowledge, no biomechanical studies have addressed the effect of vertebral augmentation at the proximal junction.PurposeTo evaluate the effectiveness of prophylactic vertebroplasty in reducing the incidence of vertebral compression fractures at the proximal junction after a long spinal fusion in a cadaveric spine model.Study designBiomechanical cadaveric study.MethodsWe divided 18 cadaveric spine specimens into three groups of six spines each: a control group, a group treated with one-level prophylactic vertebroplasty at the upper instrumented vertebra, and a group treated with two-level prophylactic vertebroplasty at the upper instrumented vertebra and the supra-adjacent vertebra. In all spines, the pedicles were instrumented from L5 to T10. Using eccentric axial loading, the specimens were then compressed until failure. Failure was defined as a precipitous decrease in load with increasing compression. The effect of augmentation on load-to-failure was checked using linear regression. The effect of augmentation on incidence of adjacent fractures was checked using logistic regression. Differences at the level of p<.05 were considered significant. KyphX cement introducer was donated by Kyphon, and the pedicle screws were donated by DePuy.ResultsFractures occurred in 12 of 18 specimens: five in the control group, six in the one-level group, and only one in the two-level group; these differences were statistically significant.ConclusionsProphylactic vertebroplasty at the upper instrumented level and its supra-adjacent vertebra reduced the incidence of junctional fractures after long posterior spinal instrumentation in this axially loaded cadaveric model. Additional studies are necessary to determine if these results are translatable to clinical practice.     

Cement-augmented anterior screw fixation of Type II odontoid fractures in elderly patients with osteoporosis

Background contextClosed reduction and internal fixation by an anterior approach is an established option for operative treatment of displaced Type II odontoid fractures. In elderly patients, however, inadequate screw purchase in osteoporotic bone can result in severe procedure-related complications.PurposeTo improve the stability of odontoid fracture screw fixation in the elderly using a new technique that includes injection of polymethylmethacrylat (PMMA) cement into the C2 body.Study designRetrospective review of hospital and outpatient records as well as radiographs of elderly patients treated in a university hospital department of orthopedic surgery.Patient sampleTwenty-four elderly patients (8 males and 16 females; mean age, 81 years; range, 62–98 years) with Type II fractures of the dens.Outcome measuresComplications, cement leakage (symptomatic/asymptomatic), operation time, loss of reduction, pseudarthrosis and revision surgery, patient complaints, return to normal activities, and signs of neurologic complications were all documented.MethodsAfter closed reduction and anterior approach to the inferior border of C2, a guide wire is advanced to the tip of the odontoid under biplanar fluoroscopic control. Before the insertion of one cannulated, self-drilling, short thread screws, a 12 gauge Yamshidi cannula is inserted from anterior and 1 to 3 mL of high-viscosity PMMA cement is injected into the anteroinferior portion of the C2 body. During polymerization of the cement, the screws are further inserted using a lag-screw compression technique. The cervical spine then is immobilized with a soft collar for 8 weeks postoperatively.ResultsAnatomical reduction of the dens was achieved in all 24 patients. Mean operative time was 64 minutes (40–90 minutes). Early loss of reduction occurred in three patients, but revision surgery was indicated in only one patient 2 days after primary surgery. One patient died within the first eight postoperative weeks, one within 3 months after surgery. In five patients, asymptomatic cement leakage was observed (into the C1–C2 joint in three patients, into the fracture in two). Conventional radiologic follow-up at 2 and 6 months confirmed anatomical healing in 16 of the19 patients with complete follow-up. In two patients, the fractures healed in slight dorsal angulation; one patient developed a asymptomatic pseudarthrosis. All patients were able to resume their pretrauma level of activity.ConclusionsCement augmentation of the screw in Type II odontoid fractures in elderly patients is technically feasible in a clinical setting with a low complication rate. This technique may improve screw purchase, especially in the osteoporotic C2 body.     

Vertebroplasty increases compression of adjacent IVDs and vertebrae in osteoporotic spines

Background contextApproximately 25% of vertebroplasty patients experience subsequent fractures within 1 year of treatment, and vertebrae adjacent to the cemented level are up to three times more likely to fracture than those further away. The increased risk of adjacent fractures postaugmentation raises concerns that treatment of osteoporotic compression fractures with vertebroplasty may negatively impact spine biomechanics.PurposeTo quantify the biomechanical effects of vertebroplasty on adjacent intervertebral discs (IVDs) and vertebral bodies (VBs).Study designA biomechanics study was conducted using cadaveric thoracolumbar spinal columns from elderly women (age range, 51–98 years).MethodsFive level motion segments (T11–L3) were assigned to a vertebroplasty treated or untreated control group (n=10/group) such that bone mineral density (BMD), trabecular architecture, and age were similar between groups. Compression fractures were created in the L1 vertebra of all specimens, and polymethylmethacrylate bone cement was injected into the fractured vertebra of vertebroplasty specimens. All spine segments underwent cyclic axial compression for 115,000 cycles. Microcomputed tomography imaging was performed before and after cyclic loading to quantify compression in adjacent VBs and IVDs.ResultsCyclic loading increased strains 3% on average in the vertebroplasty group when compared with controls after 115,000 cycles. This global strain manifested locally as approximately fourfold more compression in the superior VB (T12) and two- to fourfold higher axial and circumferential deformations in the superior IVD (T12–L1) of vertebroplasty-treated specimens when compared with untreated controls. Low BMD and high cement fill were significant factors that explained the increased strain in the vertebroplasty-treated group.ConclusionsThese data indicate that vertebroplasty alters spine biomechanics resulting in increased compression of adjacent VB and IVD in severely osteoporotic women and may be the basis for clinical reports of adjacent fractures after vertebroplasty.     

手术治疗移位的肱骨大结节骨折的临床研究

目的探讨手术切开复位使用螺丝钉配合带线锚钉内固定治疗移位的肱骨大结节骨折的效果。方法2007年1月至2012年6月,本组共收治了35例肱骨大结节骨折患者,男26例,女9例,年龄20～68岁,其中24例摔伤,5例车祸外伤,6例运动中损伤,其中合并肩关节脱位32例,受伤至手术时间8h-3周。手术中对于骨折移位大于5mm大结节骨折块采用螺丝钉配合带线锚钉进行固定。结果患者伤口均一期愈合,无感染等并发症发生,所有患者均获随访,随访时间6～18个月,平均12个月。x线显示术后约6—10个月骨折愈合。按照Neer肩关节百分评分标准进行,疼痛、功能、活动度、解剖复位四个方面分别评分,总体优良率92．85％。结论采用手术切开复位螺丝钉配合带线锚钉治疗移位的肱骨大结节骨折疗效满意,功能恢复良好,疼痛缓解明显。     

尺神经沟置针术式治疗儿童GartlandⅢ型肱骨髁上骨折

背景：交叉克氏针内固定是目前治疗儿童GartlandⅢ型肱骨髁上骨折的首选方法,但仍未从根本上解决并发症发生问题。目的：评价尺神经沟置针术式治疗儿童GartlandⅢ型肱骨髁上骨折的可行性及疗效。 方法：1998年1月到2010年10月采用尺神经沟置针术式治疗儿童GartlandⅢ型肱骨髁上骨折患儿144例,随访时检查环小指运动及感觉情况,测量双上肢长度、肘关节活动度,摄双肘正位片测量Baumann角或提携角。采用HSS肘关节功能评价法评分标准进行肘关节功能评定。 结果：144例患儿,随访14~85个月,平均60个月,根据HSS肘关节功能评定法行功能评价：优140例,良4例,无肘内翻和肘外翻畸形发生,无继发尺神经损伤,肢体无短缩。 结论：尺神经沟置针术式治疗儿童GartlandⅢ型肱骨髁上骨折可获得良好的肘关节功能及外观,预防了肘内翻畸形及继发尺神经损伤,且对骨骺生长发育无明显影响。     

桡骨远端掌侧解剖锁定接骨板治疗桡骨远端骨质疏松性骨折的疗效观察

背景：近年来桡骨远端掌侧（DVR）解剖锁定接骨板广泛应用于桡骨远端骨折的治疗,尤其是桡骨远端骨质疏松性骨折。目的：评价DVR解剖锁定接骨板治疗桡骨远端骨质疏松性骨折的临床疗效。方法：2009年5月至2011年12月共收治桡骨远端骨折87例,确诊为桡骨远端骨质疏松性骨折的29例行DVR解剖锁定接骨板掌侧入路固定。男11例,女18例;年龄56-78岁,平均63岁;骨折按AO分型：A2型3例,A3型6例,B1型1例,B3型2例,C1型6例,C2型7例,C3型4例;受伤距手术时间为1～12d,平均5d。结果：术后伤口均一期愈合,无一例出现术后感染。29例中21例获得随访,随访时间为12～20个月,平均14个月。影像学检查示均达到骨性愈合,愈合时间为12～18周,平均15周。末次随访时患者腕关节活动度：背伸41°～68°,平均52°;掌屈45°～78°,平均57°;旋前63°～86°,平均77°;旋后57°～80°,平均74°。末次随访采用Sarmiento改良Gartland＆Werley评分方法：优13例,良6例,可2例,差0例;腕关节VAS评分：腕关节完全无痛18例,轻度疼痛2例（评分为2分和2.5分）,中度疼痛1例（评分为4分）。无一例出现肌腱激惹;正中神经卡压1例,骨折愈合后6个月取出内固定并行松解术后症状完全消失;骨折背侧骨片移位1例,未对腕关节功能产生影响遂未予以处理。在背伸、掌屈、旋前、旋后4个方向的活动度比较,A型与B型骨折比较无统计学差异;A型与C型,B型与C型比较均存在统计学差异。结论：DVR解剖锁定接骨板板治疗桡骨远端骨质疏松性骨折可以获得良好的功能转归,C型骨折较A、B型骨折对腕关节活动影响更大。     

Hip prosthesis introduction and early revision risk: A nationwide population-based study covering 39,125 operations

A report is made of experience with the conservative treatment of old scaphoid fractures and pseudarthroses. The bandaging technique practised for this is of decisive importance and consists of a non-upholstered plaster cast enclosing all the fingers, so that complete immobilisation of the fragments is achieved. On average Ibis is maintained for 3–4½ months. Even with unfavourable initial conditions such as a small ulnar fragment healing is obtained. Cases with severe, deforming articular metamorphoses, considerable unevenness of the fracture surfaces and dislocation of the fragments are not suited to conservative therapy.     

Treatment of sequelae of radial head fractures with a bipolar radial head prosthesis: Good outcome after 1–4 years follow-up in 11 patients

Background?In the presence of additional disruption of the distal radioulnar ligaments, the interosseous membrane, or the lateral- and/or medial collateral ligament, radial head fractures treated by resection will result in valgus elbow instability, proximal radial migration and/or posterolateral rotatory instability. Radial head replacement has been used to treat or prevent this. We report our experience with the Judet CRF II radial head prosthesis.

Patients and methods?We treated 11 patients with a bipolar radial head prosthesis because of elbow instability after previous treatment for Mason-Johnston type III or IV radial head fractures. The outcome was assessed clinically using two standardized elbow function assessment scales, and radiographically after a mean follow-up of 2 years.

Results?Clinical outcome was either good or excellent in all patients; all elbows were stable. Radiographically, there were no signs of loosening, fracture or heterotopic ossification. 2 patients required reoperation for subluxation of the prosthesis; both were treated by reducing the size of the modular head of the prosthesis. There was erosion of the capitellum in 1 patient.

Interpretation?Bipolar radial head replacement can be used successfully for treatment of the sequelae of radial head fractures. The long-term outcome is, however, unknown.

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Arthroplasty for ochronotic arthritisNo failure of 11 replacements in 3 patients followed 6–12 years

Background?Alkaptonuria is a rare single-gene disorder characterized by black pigmentation of cartilage and other connective tissues. Premature degenerative arthritis affects the large joints in many of these of patients. Medical treatment is limited to a protein-restricted diet (phenylalanine and tyrosine) with surgery reserved for end-stage joint disease. As in other metabolic bone diseases, there are concerns about the quality and strength of affected bones and therefore the suitability and longevity of replacement arthroplasty. The histopathology and outcome of joint replacement for alkaptonuric arthritis is unknown and limited to sporadic case reports.Patients and results?We describe 11 joint replacements in 3 patients with alkaptonuric polyarthropathy, including shoulder and elbow replacements not previously reported. No prosthetic failures occurred in up to 12 years of follow-up.Interpretation?Total joint replacement is an acceptable treatment for degenerative joint disease in alkaptonuric patients, with implant survival comparable to that found in patients with osteoarthritis.