Factors affecting impingement and dislocation after total hip arthroplasty – Computer simulation analysis

BackgroundStudies on the causes and factors affecting dislocation after total hip arthroplasty have revealed conflicting results. The purpose of this study was to evaluate the factors affecting impingement and dislocation after total hip arthroplasty, using a 3-dimensional dynamic motion analysis.MethodsThe CT data of 53 patients (53 hips: anterior dislocation; 11 cases, and posterior dislocation; 42 cases) who experienced hip dislocation after total hip arthroplasty with posterior approach, and 120 control patients (120 hips) without dislocation were analyzed. Parameters related to implant alignment, offset and leg length were evaluated. The impingement type was also analyzed using a software.FindingsConsidering implant settings affecting dislocation, patients at risk for posterior dislocation had decreased stem anteversion, combined anteversion, femoral offset, and leg length. Nevertheless, patients at risk for anterior dislocation had only lower leg length, and these patients may also be at risk for a higher incidence of recurrent dislocation. Bony impingement occurred in almost half of the cases with posterior dislocation, while implant impingement was associated with anterior dislocation. Importantly, anterior dislocation was not as common as posterior dislocation even in cases with occurrence of posterior impingement.InterpretationBony impingement substantially affects dislocation even in the situation where the implant position and alignment are determined by the so-called “safe zone”, especially on the anterior side, while implant impingement affects anterior dislocation. The restoration of anterior offset (i.e., prescribed by the stem anteversion and femoral offset) and combined anteversion is critical for avoidance of posterior dislocation after total hip arthroplasty.     

Manubriosternal Joint Dislocation: An Unusual Risk of Trampolining

Background: Manubriosternal joint (MSJ) dislocation is a rare but potentially serious injury that can be associated with concurrent injuries to ribs, lungs, or myocardium. Two distinct types of MSJ dislocation have been described in the literature: type I, involving posterior dislocation of the sternum due solely to direct trauma; and type II, involving the sternum being pushed anteriorly as a result of indirect trauma. Until now, the relationship between the nature of the forces acting on the sternum and the type of MSJ dislocation that results has been absolute, whereby indirect forces never cause a type I dislocation, and direct forces never result in a type II dislocation. Objectives: To describe a case demonstrating that type I MSJ dislocation can occur without direct trauma. Case Report: A 14-year-old boy developed sternal pain accompanied by an audible crack while executing a maneuver on a trampoline that required hyperflexion of the thorax. A lateral chest radiograph demonstrated a type I manubriosternal dislocation normally associated with direct trauma, as opposed to the more typical type II dislocation pattern one would expect to find in a hyperflexion injury. Conclusion: MSJ dislocations are classified into two groups, depending on the position of the sternum in relation to the manubrium. Each type of dislocation has been ascribed to either direct forces (for type I dislocation) or indirect forces (for type II dislocation). This case highlights that it is possible to have a type I dislocation in the absence of any direct sternal trauma.     

髋关节镜检查和治疗急性髋关节后脱位的护理

髋关节后脱位占髋关节脱位的85％～90％,常合并关节内游离体、髋臼骨折、盂唇损伤.髋关节后脱位宜在24～48 h内麻醉下复位,急诊髋关节镜检查和治疗在同一麻醉下关节复位后进行1h左右完成手术,损伤小、并发症少、很少增加患者痛苦,且及时予以关节镜下摘除游离体、关节清理、检查髋关节骨折情况而后予以指导Ⅱ期手术,易被患者接受.我院2005年8月～2010年10月髋关节镜术检查治疗急性髋关节后脱位37例,疗效满意,现将护理体会报告如下.     

腕关节脱位形成机制及其X线表现

目的分析腕关节脱位形成机制及其X线表现,提高对本病的诊断水平。方法10例腕关节脱位病例,男8例,女2例,年龄12～65岁,对其形成机制及X线表现进行分析。结果下尺桡关节脱位2例,桡腕关节脱位5例,腕骨间关节脱位3例。结论详细了解病史,熟悉腕关节正常X线表现,掌握各型腕关节脱位的X线特点,可防止漏诊发生。     

Medial subtalar dislocation: importance of clinical diagnosis in distinguishing from other dislocations.

In an emergency situation, the clinical picture of ankle and subtalar dislocation may be similar. This may lead to the use of the improper technique of reduction, especially in a subtalar dislocation, resulting in the failure of reduction and further damage to the articular surfaces. A case of medial subtalar dislocation is presented, which was managed as an ankle dislocation and manipulated inappropriately, leading to a failure of reduction. The clinical signs of ankle and subtalar dislocation, including points of differentiation between the two are discussed, and the correct method of reduction of subtalar dislocation is described.     

Injuries of the talus.

Forced plantar flexion can result in tibiotalar dislocation, subtalar dislocation and total dislocation of the talus. Forced dorsal flexion can cause fracture of the neck of the talus, with or without subtalar dislocation, or dislocation of the body of the bone. Accurate diagnosis is important and sometimes difficult. Reduction must be prompt. Complications include osteomyelitis, malunion and avascular necrosis of the talar body. The last may be partial and revascularization can occur.     

Acute atraumatic hip dislocation in an adult with rheumatoid arthritis

There are no reports of atraumatic hip subluxation and dislocation in the adult patient with rheumatoid arthritis (RA). This rare phenomenon is most prevalent in patients with congenital hip dislocation, von Recklinghausen disease, tumor infiltration, connective tissue disorders, and juvenile rheumatoid arthritis. We report an acute atraumatic dislocation of the hip in an adult patient with RA. We believe that two factors contributed to the patient's atraumatic dislocation: a shallow but appropriately positioned acetabulum and erosive RA with substantiate panus formation. Similar to previous reports, there was a rent or capsular defect that may have contributed to the mechanism of dislocation. Physicians should be aware that, although rare, a de novo atraumatic hip dislocation is a possibility in a patient with a long-standing history of RA and hip pain. Distinguishing features of this case include the acuteness of the dislocation, the absence of previous symptoms, and adult-onset RA.     

Combined bilateral asymmetric hip dislocation and anterior shoulder dislocation

BACKGROUND:

Traumatic bilateral hip dislocation is a rare condition. Anterior shoulder dislocation combined with this condition is even a rare occurrence. A 57-year-old man had bilateral asymmetric hip dislocation with a posterior wall fracture of the left acetabulum associated with right shoulder anterior dislocation caused by falling down from a cherry tree. Traumatic hip dislocation and anterior shoulder dislocation represent a true orthopedic emergency.

METHODS:

Closed reduction was performed immediately for three of the dislocated joints. Posterior wall fracture of the left acetabulum was treated with open reduction and internal fixation by screws. Because of the severity of associated complications like aseptic necrosis or posttraumatic osteoarthritis, efforts were made to ensure prompt diagnosis, therapy and prognosis.

RESULTS:

The patient was successfully treated by open reduction and internal fixation of the left acetabulum, and discharged from the hospital.

CONCLUSION:

Traumatic asymmetric hip dislocation and anterior shoulder dislocation are an orthopedic emergency and early diagnosis with immediate reduction of the dislocation is the key determinants of excellent result of treatment.KEY WORDS: Trauma, Asymmetric hip dislocation, Shoulder dislocation, Immediate therapy     

颞下颌关节脱位的手法治疗

Background: That the condylar process slides out of articular fossa and exceeds normal limit of articular motion and can not reduce automatically is called dislocation of temporomandibular joint. It is divided into unilateral and bilateral dislocation according to the part of dislocation. Or it is divided into acute, recurrent, and old dislocations according to the time of dislocation or into anterior, posterior, superior and lateral dislocations according the direction of dislocation of the condylar process. Manifestations of dislocation of temporomandibular joint include mandibular abnormal motion, opening of the mouth that can' t close with outflowing of the saliva, he mandible protrudes anteriorly, the cheeks become smooth, a pit can be palpated anterior to the antilobium.     

Bilateral anterior shoulder dislocation: a case report.

Bilateral anterior shoulder dislocation is a very rare clinical entity. All the cases reported so far highlight a simultaneous bilateral shoulder dislocation. We report an unusual case, where the left shoulder dislocated first due to trauma followed by atraumatic dislocation of the right shoulder. A new manoeuvre--the Spaso Technique was used to reduce the dislocation.     

肩锁关节的脱位及修复重建

背景：目前临床认为Rockwood Ⅰ、Ⅱ型急性肩锁关节脱位应行非手术治疗,Ⅳ、Ⅴ、Ⅵ型急性肩锁关节脱位应行手术治疗,但对Ⅲ型急性肩锁关节脱位的治疗方法仍存在争议。此外,肩锁关节脱位修复方法繁多,其中以喙锁韧带和肩锁韧带解剖重建以恢复肩锁关节生物力学为治疗趋势,在此形式下,肩锁关节及相关解剖结构被越来越多的学者所重视。目的：综合分析肩锁关节脱位的修复重建现状。方法：由第一作者检索至2014年5月为止PubMed数据（http：//www.ncbi.nlm.nih.gov/PubMed）、万方全文数据库（http：//g.wanfangdata.com.cn/）有关肩锁关节解剖结构及脱位修复的文献,以“acromioclavicular, acromioclavicular joint dislocation,endobutton”为英文检索词,“肩锁关节脱位,解剖重建”为中文检索词,排除重复性研究。计算机初检得到1632篇文献,最后保留43篇文献归纳总结。结果与结论：肩锁关节脱位的修复方法多样,目前越来越趋向于解剖重建,包括肌腱移植、endobutton技术等,在此趋势下,对肩锁关节的基础研究被充分带动起来,但由于缺乏大样本、多中心的临床对照研究,目前肩锁关节脱位的最佳治疗方案仍然在不断探索中。     

Prereduction radiographs in clinically evident anterior shoulder dislocation

The main study objective was to determine if experienced emergency physicians can accurately identify a subgroup of patients with anterior shoulder dislocation for whom prereduction radiographs do not alter patient management. Our prospective study evaluated 97 patients who presented to 2 ski-hill clinics and to our rural emergency department with possible shoulder dislocation between November 1996 and May 1997. Emergency physicians were certain of shoulder dislocation by clinical examination alone in 40 of 59 cases (67.8%) of possible dislocation. All 40 cases were found to have a dislocation (100%; 95% Cl, 91.19% to 100%), and the prereduction radiograph did not affect management of the injury. Prereduction radiographs added 29.6 +/- 12.68 minutes to treatment. We conclude that shoulder dislocation is often readily apparent from history and physical examination. When the experienced emergency physician is certain of the diagnosis of anterior shoulder dislocation, prereduction radiography delays treatment and does not alter management.     

排粪功能造影对尾骨直肠综合症患者骶尾骨损伤的诊断价值

目的:对尾骨直肠综合症患者的骶尾骨损伤情况进行排粪功能造影观察分析,讨论其诊断价值。方法:选择68例尾骨直肠综合症的患者,归纳总结骶尾骨X光片、排粪造影的影像表现,对骶尾损伤检出率进行列表比较分析,并做卡方检验。结果:68例尾骨直肠综合症患者中,骶尾骨单纯脱位30例,骨折合并脱位38例。普通X光片检出31例,其中单纯脱位7例,骨折合并脱位24例。排粪功能造影检出61例,其中单纯脱位27例,骨折合并脱位34例。两种检查方法对骶尾骨损伤的检出有显著差异(X^2=30.237,P<0.001),对单纯脱位的检出有显著差异(X^2=24.502,P<0.001)。对骨折合并脱位检出差异性相对稍小(X^2=5.897,P<0.05)。结论:排粪功能造影对骶尾损伤有明显的诊断价值,有助于提高尾骨直肠综合症检查的准确率,指导临床综合治疗。     

带线锚钉动力性固定治疗胸锁关节脱位

目的探讨带线锚钉动力性固定治疗胸锁关节脱位的方法及疗效,以提高胸锁关节脱位的治疗水平。方法对本院收治的11例胸锁关节脱位患者采用Arthrex带线锚钉动力性固定和张力带固定治疗。结果所有患者均获随访,随访时间6个月~5年。A组术后切口愈合良好,外观美观,X线片示脱位复位良好,锚钉位置良好,患者疗效根据Rockwood评分法进行评定,11例均为优,未见内固定失效及再脱位等副损伤。B组优7例,良2例。A组并发症少于B组。结论带线锚钉动力性固定治疗胸锁关节脱位具有符合生理功能、创伤小、术后美观、手术时间短、固定可靠、避免二次手术取出内固定等特点,值得临床推广。     

品质圈在髋关节置换术后防止假体脱位的应用

目的探讨品质圈(quality circle,QC)在髋关节置换术后防止假体脱位的应用。方法成立QC小组,采用回顾性分析的方法,分析QC活动前本科室影响髋关节置换术后假体脱位的各种因素,组织全科护士针对影响因素制订对策并实施。比较实施QC前后患者假体脱位的发生率。结果实施QC后,患者髋关节置换术后假体脱位发生率低于对照组(P<0.05)。结论 QC能针对出现的问题进行讨论分析,并制订实施对策,可降低人工髋关节置换术后假体脱位的发生率,提高护理质量。     

晶状体后脱位的彩色多普勒超声诊断价值

目的：探讨晶状体后脱位的超声诊断价值。方法：应用彩色多普勒超声对38例不同类型的晶状体后脱位患者的眼球进行超声检查，了解晶状体在眼内的位置、形态、回声以及与周围组织的关系。结果：完全性品状体后脱位13例，人工晶状体后脱位3例，不完全性品状体后脱位22例。合并玻璃体出血4例，玻璃体混浊、增殖及机化13例，玻璃体后脱离15例，视网膜脱离3例。38例患者中33例进行了玻璃体切除联合品状体切除或取出术，超声诊断符合率100％。结论：超声在晶状体后脱位的诊断中具有很高的实用价值，是临床上诊断晶状体后脱位的重要手段之一；同时，为晶状体后脱位手术治疗方法的选择提供有价值的参考。     

The wrist pivot method, a novel technique for temporomandibular joint reduction

Temporomandibular joint (TMJ) dislocation is an infrequent dislocation of the mandible. The usual technique of reduction, recommended by most Emergency Medicine textbooks, consists of downward forces applied to the mandible. In the authors' experience this is often painful and requires significant sedation. We present a patient in whom the usual manner of TMJ dislocation reduction was difficult. We describe a novel technique for TMJ dislocation reduction that uses the intrinsic biomechanical properties of the mandible.     

Luxation sous-talienne pure chez un footballeur (à propos d’un cas)

Medial subtalar dislocation is a rare dislocation and is not commonly seen as a sport injury. The authors report the case of a footballer who presented a medial subtalar dislocation. The treatment was orthopedic with a very good functional result.     

Detecting cause of dislocation after total hip arthroplasty by patient-specific four-dimensional motion analysis

Background

Dislocation is a major complication after total hip arthroplasty. Prosthesis impingement is considered to be an important cause of dislocation because impingement marks are more frequently found on retrieved cups or liners in patients who have undergone revision surgery because of dislocation (80%–94%) than in those who have undergone reoperation for other reasons (51%–56%). However, it remains a question whether impingement marks are the cause of dislocation or are instead its result. To clarify the issue, it is necessary to confirm noninvasively whether the point of impingement matches the patient's hip position when dislocation occurs.

Methods

Using four-dimensional patient-specific analysis, we recorded prosthesis impingement in 10 hips with instability after primary total hip arthroplasty when the patients reproduced the dislocation-causing motion.

Findings

We found prosthesis impingement to be related to at least instability in 6 of 10 hips with dislocation after primary total hip arthroplasty and in 4 of 4 hips that underwent revision surgery for recurrent dislocation. All impingements occurred between the anterior wall of the liner and the stem neck in posterior dislocation and between the posterior wall of the liner and the stem neck in anterior dislocation. Revision surgery in 1 of those 4 hips revealed 2 impingement marks on the retrieved liner that closely matched the prosthesis impingement point and the dislocation pathway of the metal head on the liner that were detected earlier during motion analysis.

Interpretation

Prosthesis impingement is an important factor in dislocation after total hip arthroplasty.     

Irreducible acute anterior shoulder dislocation

Irreducible acute anterior dislocation of the shoulder has rarely been reported in the literature. This report describes a shoulder dislocation in a patient, which required open disimpaction of the humeral head from the glenoid before reduction of the glenohumeral dislocation could be achieved.