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Sample records for hip dislocation

  1. Bilateral traumatic hip dislocation associated with sacro-iliac dislocation.

    PubMed

    Galois, L; Meuley, E; Pfeffer, F; Mainard, D; Delagoutte, J P

    We report a rare injury in an 18-year-old woman who sustained posterior bilateral hip dislocation with sacro-iliac dislocation after a high energy motor vehicle accident. She was treated by closed reduction and skeletal traction. Bilateral traumatic hip dislocation is an uncommon occurrence. Rarer still is bilateral traumatic hip dislocation associated with sacro-iliac dislocation because it combines two different mechanisms of trauma. (Hip International 2002; 1: 47-9).

  2. Developmental Dislocation (Dysplasia) of the Hip (DDH)

    MedlinePlus

    ... developmental dysplasia (dislocation) of the hip (DDH), the hip joint has not formed normally. The ball is loose ... be taken to provide detailed pictures of the hip joint. Treatment When DDH is detected at birth, it ...

  3. [Arthrography in congenital hip dislocation].

    PubMed

    Sipukhin, Ia M; Bazlova, E S; Cheberiak, N V

    1992-01-01

    The paper is concerned with the results of contrast arthrography in 73 children with hip joint dysplasia, among which true dislocations prevailed (70 patients). In addition to bone alterations, arthrography revealed various soft tissue changes like hypertrophy and deformity of limbus, soft tissue interposition, separation of the articular sac with the presence of an isthmus, disintegration of articular cartilages. These findings are used to define indications for surgical intervention as well as for planning the area of operation.

  4. Traumatic posterior dislocation of hip in children.

    PubMed

    Kutty, S; Thornes, B; Curtin, W A; Gilmore, M F

    2001-02-01

    Traumatic posterior dislocation of the hip joint in children is an uncommon injury. It constitutes a true orthopedic emergency. It makes up over 80% of pediatric hip dislocations. In children, it can occur as a result of minimal trauma, which is attributed to a soft pliable acetabulum and ligamentous laxity. In skeletally mature adolescents, a greater force is required to dislocate the hip joint. Delay in reduction is associated with long-term complications such as avascular necrosis and degenerative arthritis. Avascular necrosis is related to the duration of dislocation. A poorer prognosis is associated with delay in reduction beyond 6 hours, advanced skeletal maturity, or multiple traumas. Prompt reduction minimizes complications. We report two cases of traumatic posterior dislocation of hip in children aged 3 and 14 years. Both were reduced within 6 hours of dislocation, and review at 6 months revealed normal examination and no evidence of any post-traumatic changes. Post-reduction treatment remains without a consensus. This review highlights the clinical presentation, management, and time-sensitive complications of the injury.

  5. Epidemiology of dislocation after total hip arthroplasty.

    PubMed

    Meek, R M D; Allan, D B; McPhillips, G; Kerr, L; Howie, C R

    2006-06-01

    Instability after total hip arthroplasty is an important complication. It usually occurs in the immediate postoperative period, but the risk also increases with time. There are numerous surgical treatment options, but they have relatively unpredictable outcomes. Numerous factors are associated with dislocation, but research has mainly focused on surgical factors. Epidemiological factors remain the subject of much debate. We aimed to establish the most significant epidemiological factors in Scotland and in particular the dislocation rate in neuromuscular conditions. The Scottish National arthroplasty nonvoluntary registry is based on SMR01 records (Scottish Morbidity Record) data. We analyzed the Scottish National Arthroplasty Project to find patients' dislocation rates up to 1 year postoperatively for surgeon volume, age, gender, previous surgery, diagnosis, and followup duration. There were 14,314 total hip arthroplasties performed from April 1996 to March 2004 with an annual incidence of dislocation of 1.9%. We found an association between rate of dislocation with age, surgical volume, and previous fracture. However, there was no increase in the rate of dislocation associated with gender or with diagnoses of stroke or Parkinson's disease. Our prognostic assessment of dislocation risk allows assessment for methods of reducing dislocation in high risk patients.

  6. [Bilateral Asymmetric Traumatic Dislocation of Hip Joints].

    PubMed

    Paša, L; Veselý, R; Kelbl, M

    2017-01-01

    The authors present a rare case of bilateral asymmetric traumatic dislocation of hip joints, where the left joint was treated conservatively after the reduction, while the right joint, with an acetabular fragment interposition, was treated surgically - by arthroscopically assisted reduction and fixation of an osteochondral fragment of posterior wall of the acetabulum. The female patient healed with no complications, showing an excellent clinical outcome with no signs of instability or limited mobility of hip joints, and also with no signs of para-articular calcification or necrosis of the hip at 1 year after the injury and treatment. Bilateral asymmetric dislocation of hip joint is a rare injury with the total incidence of 150 cases as reported by the literature. Recently, its incidence is higher due to the increased traffic and the associated accident rate. A precise and prompt reduction of the injured hip joint is always necessary, if possible under general anesthesia. Also, it is always necessary to carry out a complete examination of the patient since this type of injury is always caused by a strong force and is often accompanied by injuries of other parts of the body. Key words: bilateral asymmetric dislocation of hip joints, hip arthroscopy, acetabular fracture.

  7. Reduction of dislocated hip with transepiphyseal fracture.

    PubMed

    Langan, P; Fontanetta, A P

    1986-09-01

    A case report of a 12-year-old boy who suffered a dislocated hip in a football game. He was unable to walk and was in severe pain when seen in the emergency room. Efforts at closed reduction of the displacement were complicated by the development of a transepiphyseal fracture.

  8. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    PubMed Central

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despite routine post-operative skeletal traction in all cases and careful soft tissue interposition. One case showed significant heterotopic ossification which restricted prolonged sitting. This patient needed some occasional medication for pain. PMID:12180614

  9. Inferior hip dislocation after falling from height: A case report

    PubMed Central

    Tekin, Ali Çağrı; Çabuk, Haluk; Büyükkurt, Cem Dinçay; Dedeoğlu, Süleyman Semih; İmren, Yunus; Gürbüz, Hakan

    2016-01-01

    Introduction Traumatic inferior hip dislocation is the least common of all hip dislocations. Adult inferior hip dislocations usually occur after high-energy trauma, very few cases are reported without fracture. Presentation of case A 26-year-old female was brought to the emergency department with severe pain in the left hip, impaired posture and restricted movement following a fall from 15 m height. The hip joint was fixed in 90° flexion, 15° abduction, and 20° external rotation. No neurovascular impairment was determined. On radiologic examination, a left ischial type inferior hip dislocation was detected. Hemorrhagic shock which developed due to acute blood loss to thoracic and abdominal cavity and patient died at third hour after she was brought to the hospital. Discussion Traumatic hip dislocations have high morbidity and mortality rates due to multiple organ damage, primarily of the extremities, chest and abdomen. In the treatment of traumatic hip dislocation, closed reduction is recommended through muscle relaxation under general anesthesia or sedation. This procedure should be applied before any intervention for concomitant extremity injuries. A detailed evaluation on emergency presentation, a multi-disciplinary approach and early diagnosis with the rapid application of imaging methods could be life-saving for such patients. PMID:27058153

  10. Traumatic bilateral knee dislocations, unilateral hip dislocation, and contralateral humeral amputation: a case report.

    PubMed

    Voos, James E; Heyworth, Benton E; Piasecki, Dana P; Henn, R Frank; MacGillivray, John D

    2009-02-01

    Bilateral traumatic knee dislocations are a rarity. We report a case of bilateral traumatic knee dislocations with concomitant right hip dislocation and complete traumatic amputation of the left, nondominant upper extremity at the level of the proximal one-third of the humerus. Angiograms revealed no evidence of popliteal artery injury. Orthopedic treatment consisted of immediate reduction of the dislocations and urgent revision amputation of the upper extremity. Staged, bilateral knee ligamentous reconstructions were performed on hospital days 24 and 29, respectively. Despite this constellation of devastating injuries, the patient had a satisfactory outcome. In patients with high-energy hip or knee dislocations, the bilateral hips and knees should be carefully examined to check for associated fractures and/or dislocations.

  11. Prevention of congenital dislocation of the hip in the newborn.

    PubMed

    Miranda, L; Palomo, J M; Monzonis, J; Marti, V

    1988-01-01

    Routine examination and early treatment of any instability in the hips of newborns has recently been called into question after a period of universal agreement. The hips of 49,937 neonates were prospectively studied by a general hip screening. Every unstable hip--449 in 317 children--was immediately treated with a Von Rosen splint for a 3-month-period. Overall, satisfactory reduction of the incidence of established congenital dislocation of the hip (CDH) was achieved. Risk factors leading to unstable hips (sex, first birth, and breech birth) and the development of CDH (time of stabilization) were considered.

  12. Traumatic hip dislocation at a regional trauma centre in Nigeria.

    PubMed

    Onyemaechi, N O C; Eyichukwu, G O

    2011-01-01

    Traumatic dislocation or fracture-dislocation of the hip is an orthopaedic emergency that is steadily increasing in incidence due to high-speed motor vehicular accidents. These injuries need to be recognized early and promptly treated to prevent morbidity and long-term complications. Some of the fundamental issues in the management of traumatic dislocations of the hip are the critical interval between injury and reduction, the type of reduction most suitable for various types of injury and the duration of immobilization that give the best results. This study was carried out at the National Orthopaedic Hospital Enugu, a regional trauma and orthopaedic centre in South-East Nigeria. The purpose of the study is to describe the pattern of presentation and to identify the factors that determine the long-term outcome in the treatment of traumatic dislocations and fracture-dislocations of the hip at Enugu, Nigeria. The case notes of all the patients that presented with traumatic dislocations and fracture-dislocations of the hip between January 2003 and December 2007 were reviewed. The information extracted and analyzed included the patients' demographics, etiology of injury, time interval before reduction, associated injuries, treatment offered, complications and follow-up. Thompson-Epstein classification was used to grade the posterior hip dislocations. The outcome of treatment was evaluated using the clinical and radiological criteria proposed by Epstein (1974). Three patients with incomplete data and two patients with central fracture dislocation were excluded from this study. Forty-eight patients with 50 hip dislocations were analyzed. The age range was 12 years to 67 years with a mean age of 34.8 years. Thirty-nine patients (81.3%) were males and 9 (18.7%) were females. Road-traffic accident was the leading cause of traumatic hip dislocation in this series, 44 cases (91.6%). Posterior dislocation occurred in 48 hips (96%) while anterior dislocation occurred in 2 hips

  13. Posterior dislocation of the hip while playing basketball

    PubMed Central

    Tennent, T. D.; Chambler, A. F.; Rossouw, D. J.

    1998-01-01

    Injuries in basketball are usually to the ankles and knees. Dislocation of the hip is usually associated with severe trauma--for example, road traffic accidents. A case is reported here in which a 22 year old club basketball player slipped on landing from a jump shot, forcing him into a side splits position from which he sustained a posterior dislocation of the hip resulting in a sciatic nerve palsy. 




 PMID:9865411

  14. Open Anterior Dislocation of the Hip in Togo

    PubMed Central

    Anani, Abalo; Yannick, Dellanh; Gamal, Ayouba; Assang, Dossim

    2016-01-01

    Anterior traumatic dislocations of the hip are much less common than posterior dislocations. To date, 14 cases of open anterior dislocation of the hip associated with such injuries, acetabular and femoral head fractures and femoral vascular and nerve damage have been reported. We present a case of a 23-year-old male who sustained open anterior dislocation of the hip with ipsilateral fracture of the greater trochanter after an accident on the public highway. Additional lesions included an iliac wing fracture and a perineal wound. We report this case because of the rarity and seriousness of this injury due to its progressive complications and difficulties related to its management, which are typical to a developing country like ours. PMID:27247749

  15. Ipsilateral open anterior hip dislocation and open posterior elbow dislocation in an adult.

    PubMed

    Kumar, Sunil; Rathi, Akhilesh; Sehrawat, Sunil; Gupta, Vikas; Talwar, Jatin; Arora, Sumit

    2014-01-01

    Open anterior dislocation of the hip is a very rare injury, especially in adults. It is a hyperabduction, external rotation and extension injury. Its combination with open posterior dislocation of the elbow has not been described in English language-based medical literature. Primary resuscitation, debridement, urgent reduction of dislocation, and adequate antibiotic support resulted in good clinical outcome in our patient. At 18 months follow-up, no signs of avascular necrosis of the femoral head or infection were observed.

  16. Bilateral hip dislocation in a 79 years patient.

    PubMed

    Alexa, O; Cozma, T; Puha, B; Alexa, I D

    2012-01-01

    Bilateral simultaneous dislocation of the hip is an unusual occurrence, especially if there is no previous history of hip abnormality or ligamentous laxity. Most of the reports published until now most frequently describe this type of injury in adults. The majority of case reports present patients with ages ranging between 20 and 30 years old, because at this age the bone is strong enough not to suffer a fracture but a dislocation. The oldest patient with bilateral simultaneous dislocation of the hip described in literature (to our knowledge) is 65 years old. We present the case of a 79 year old man that was involved in an agricultural accident in which a heavy load fell on both his feet while he was laying on the ground. Anteroposterior pelvic radiograph reveal bilateral posterior hip dislocation with an associated left-side acetabular fracture and also a minimum displaced anterior left pelvic ring fracture. Both hips were reduced within three hours of presentation by closed manipulation under spinal anaesthesia. Literature search revealed no case presentation that reported a bilateral simultaneous dislocation of the hip in elderly--to our knowledge, this is the first.

  17. Surgical hip dislocation for treatment of cam femoroacetabular impingement

    PubMed Central

    Chaudhary, Milind M; Chaudhary, Ishani M; Vikas, KN; KoKo, Aung; Zaw, Than; Siddhartha, A

    2015-01-01

    Background: Cam femoroacetabular impingement is caused by a misshapen femoral head with a reduced head neck offset, commonly in the anterolateral quadrant. Friction in flexion, adduction and internal rotation causes limitation of the hip movements and pain progressively leading to labral and chondral damage and osteoarthritis. Surgical hip dislocation described by Ganz permits full exposure of the hip without damaging its blood supply. An osteochondroplasty removes the bump at the femoral head neck junction to recreate the offset for impingement free movement. Materials and Methods: Sixteen patients underwent surgery with surgical hip dislocation for the treatment of cam femoroacetabular impingement by open osteochondroplasty over last 6 years. Eight patients suffered from sequelae of avascular necrosis (AVN). Three had a painful dysplastic hip. Two had sequelae of Perthes disease. Three had combined cam and pincer impingement caused by retroversion of acetabulum. All patients were operated by the trochanteric flip osteotomy with attachments of gluteus medius and vastus lateralis, dissection was between the piriformis and gluteus minimus preserving the external rotators. Z-shaped capsular incision and dislocation of the hip was done in external rotation. Three cases also had subtrochanteric osteotomy. Two cases of AVN also had an intraarticular femoral head reshaping osteotomy. Results: Goals of treatment were achieved in all patients. No AVN was detected after a 6 month followup. There were no trochanteric nonunions. Hip range of motion improved in all and Harris hip score improved significantly in 15 of 16 cases. Mean alpha angle reduced from 86.13° (range 66°–108°) to 46.35° (range 39°–58°). Conclusion: Cam femoroacetabular Impingement causing pain and limitation of hip movements was treated by open osteochondroplasty after surgical hip dislocation. This reduced pain, improved hip motion and gave good to excellent results in the short term. PMID

  18. Surgical treatment of hip dislocation in amyoplasia-type arthrogryposis.

    PubMed

    Wada, Akifusa; Yamaguchi, Toru; Nakamura, Tomoyuki; Yanagida, Haruhisa; Takamura, Kazuyuki; Oketani, Yutaka; Kubota, Hideaki; Fujii, Toshio

    2012-09-01

    We reviewed our clinical and radiographic results in the operative treatment of five unilateral and six bilateral hip dislocations in 11 patients with amyoplasia-type arthrogryposis. The mean age at surgery was 1.8 (range, 1.1-3.2) years. Femoral and/or pelvic osteotomies were combined with an open reduction. The mean follow-up period was 12.7 (range, 5.2-23.2) years. Nine patients were community walkers and two were household walkers. The range of motion and the St Clair hip score of the bilateral hips were not significantly different from those of the unilateral hips. Successful reduction increases the ambulation potential in both unilateral and bilateral hip dislocations.

  19. Ultrasound Characteristics of Clinically Dislocated But Reducible Hips With DDH.

    PubMed

    Striano, Brendan; Schaeffer, Emily K; Matheney, Travis H; Upasani, Vidayadhar V; Price, Charles T; Mulpuri, Kishore; Sankar, Wudbhav N

    2017-07-21

    Although ultrasound (US) is frequently used in diagnosis and management of infantile developmental dysplasia of the hip, precise ultrasonographic parameters of what constitutes a dislocation, subluxation etc remain poorly defined. The purpose of this study was (1) to describe the ultrasonographic characteristics of a large cohort of clinically dislocated but reducible hips and (2) to begin to develop ultrasonographic definitions for what constitutes a hip dislocation. A retrospective review of prospectively collected data from an international multicenter study group on developmental dysplasia of the hip was conducted on all patients under 6 months of age with hip(s) that were dislocated at rest but reducible based on initial physical examination (ie, Ortolani positive). Femoral head coverage (FHC), alpha angle (α), and beta angle (β) were measured on pretreatment US by the individual treating surgeon, and were recorded directly into the database. Based on 325 Ortolani positive hips, the median FHC on presentation was 10% with an interquartile range of 0% to 23%. A total of 126 of the 327 hips (39%) demonstrated 0% FHC. The 90th percentile was found to be at 33% FHC. Of 264 hips with sufficient α data, the median α was 43 degrees with an interquartile range from 37 to 49 degrees. The 90th percentile for α was at 54 degrees. A total of 164 hips had documented β with a median of 66 degrees and an interquartile range of 57 to 79 degrees; the 90th percentile was at 94 degrees. Analysis of a large cohort of patients with dislocated but reducible hips reveals a median percent FHC of 10%, a median α of 43 degrees, and a median β of 66 degrees on initial US. Using a threshold at the 90th percentile, a sensible ultrasonographic definition of a dislocated hip seems to be FHC≤33%, implying that FHC between 34% and 50% may be reasonably termed a subluxation. Although these findings are consistent with previous, smaller reports, further prospective research is

  20. Resection arthroplasty of the hip in paralytic dislocations.

    PubMed

    Kalen, V; Gamble, J G

    1984-06-01

    The chronically dislocated paralytic hip causes postural difficulties, nursing and hygiene problems, and pain. Therapeutic options are limited. This study reviews the results of resection arthroplasty on 18 hips of 15 such patients. This procedure has many complications, including hip ankylosis, heterotopic ossification, abduction contracture and bony overgrowth. Despite this, all of the nursing goals were achieved and most patients had relief of pain. The operation is most successful in the skeletally mature patients, and it relies on soft-tissue interposition between the bony fragments and postoperative positioning to ensure optimum posture.

  1. 21 CFR 890.3665 - Congenital hip dislocation abduction splint.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Congenital hip dislocation abduction splint. 890.3665 Section 890.3665 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...

  2. 21 CFR 890.3665 - Congenital hip dislocation abduction splint.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Congenital hip dislocation abduction splint. 890.3665 Section 890.3665 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...

  3. 21 CFR 890.3665 - Congenital hip dislocation abduction splint.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Congenital hip dislocation abduction splint. 890.3665 Section 890.3665 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...

  4. 21 CFR 890.3665 - Congenital hip dislocation abduction splint.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Congenital hip dislocation abduction splint. 890.3665 Section 890.3665 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...

  5. 21 CFR 890.3665 - Congenital hip dislocation abduction splint.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Congenital hip dislocation abduction splint. 890.3665 Section 890.3665 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...

  6. Impingement and Dislocation in Total HIP Arthroplasty: Mechanisms and Consequences

    PubMed Central

    Brown, Thomas D; Elkins, Jacob M; Pedersen, Douglas R; Callaghan, John J

    2014-01-01

    In contemporary total hip arthroplasty, instability has been a complication in approximately 2% to 5% of primary surgeries and 5% to 10% of revisions. Due to the reduction in the incidence of wear-induced osteolysis that has been achieved over the last decade, instability now stands as the single most common reason for revision surgery. Moreover, even without frank dislocation, impingement and subluxation are implicated in a set of new concerns arising with advanced bearings, associated with the relatively unforgiving nature of many of those designs. Against that backdrop, the biomechanical factors responsible for impingement, subluxation, and dislocation remain under-investigated relative to their burden of morbidity. This manuscript outlines a 15-year program of laboratory and clinical research undertaken to improve the scientific basis for understanding total hip impingement and dislocation. The broad theme has been to systematically evaluate the role of surgical factors, implant design factors, and patient factors in predisposing total hip constructs to impinge, sublux, and/or dislocate. Because this class of adverse biomechanical events had not lent itself well to study with existing approaches, it was necessary to develop (and validate) a series of new research methodologies, relying heavily on advanced finite element formulations. Specific areas of focus have included identifying the biomechanical challenges posed by dislocation-prone patient activities, quantifying design parameter effects and component surgical positioning effects for conventional metal-on-polyethylene implant constructs, and the impingement/dislocation behavior of non-conventional constructs, quantifying the stabilizing role of the hip capsule (and of surgical repairs of capsule defects), and systematically studying impingement and edge loading of hard-on-hard bearings, fracture of ceramic liners, confounding effects of patient obesity, and subluxation-mediated worsening of third body

  7. Surgical hip dislocation does not result in atrophy or fatty infiltration of periarticular hip muscles

    PubMed Central

    Glynn, Aaron A.; Barattiero, Fabio Y.; Albers, Christoph E.; Hanke, Markus S.; Steppacher, Simon D.; Tannast, Moritz

    2014-01-01

    Surgical hip dislocation is the gold standard for treatment of femoroacetabular impingement (FAI). It utilizes an intermuscular and internervous approach to the hip. Concerns have been expressed that this approach causes soft tissue trauma resulting in post-operative muscle weakness of patients undergoing this procedure. We therefore asked whether surgical hip dislocation leads to (i) atrophy (decreased muscle diameter or cross-sectional area [CSA]) and (ii) degeneration (fatty infiltration) of 18 evaluated periarticular hip muscles. We retrospectively evaluated 32 patients (34 hips) following surgical hip dislocation for the treatment of FAI using pre and post-operative magnetic resonance (MR) arthrography of the hip. We evaluated muscle diameter, CSA and degree of fatty infiltration according to Goutallier for 18 periarticular hip muscles on axial and sagittal views. The mean interval between pre and post-operative MR was 1.9 ± 1.5 years (range, 0.4–6.1 years). Pre and post-operative muscle diameter and CSA of all 18 evaluated hip muscles did not differ. There was no post-operative change in the Goutallier classification for any of the evaluated 18 muscles. No muscle had post-operative degeneration higher than Grade 1 according to Goutallier. No atrophy or degeneration of periarticular hip muscles could be found following surgical hip dislocation for treatment of FAI. Any raised concerns about the invasiveness and potential muscle trauma for this type of surgery are unfounded. Level III, retrospective comparative study. See guidelines for authors for a complete description of levels of evidence. PMID:27011807

  8. Total hip arthroplasty in paralytic dislocation from poliomyelitis.

    PubMed

    Laguna, Rafael; Barrientos, Jesús

    2008-02-01

    This article presents a case of a patient with degenerative hip disease in paralytic dislocation by poliomyelitis. Poliomyelitis is an acute infection disease caused by a group of neurotrophic viruses, which has a special affinity by the anterior horns cells of the spinal cord and for certain motor nuclei of the brain stem. Paralysis is a flaccid type and characteristically paralysis is asymmetrical. It is said that the joints of the affected limb by poliomyelitis are protected from the development of osteoarthritis. Hip dislocation in poliomyelitis is an acquired deformity caused by flaccid paralysis and the resulting muscular imbalance. In young children, when the gluteus maximus and medius muscles are paralyzed and the hip flexors and adductors are of normal strength, eventual luxation of the hip is almost inevitable. Hip osteoarthritis in a limb with poliomyelitis is an unusual entity because these limbs do not support excessive loads. In patients who present with the residual effects of poliomyelitis including degenerative disease and hip dysplastic, surgery is one of the most difficult challenges faced by reconstructive surgeons. In such cases, surgeons should attempt to optimize the component position and choice, surgical approach, and soft tissue tensioning because stability of the prosthesis can be problematic.

  9. Asymmetric bilateral hip dislocation after motor vehicle accident - a case study and review of the literature.

    PubMed

    Sanders, Samuel; Tejwani, Nirmal C

    2008-01-01

    Bilateral asymmetric dislocations of the hip are rare compared to unilateral dislocations. This case study describes a female restrained passenger involved in a motor vehicle accident who sustained asymmetric bilateral hip dislocations. The patient underwent successful closed reduction of both hips. The clinical course and follow-up assessment of the patient was otherwise uneventful. Computed tomography scans, essential for diagnosing intra-articular loose bodies and subtle fractures, were performed after reduction and revealed in the right hip a nondisplaced acetabular rim fracture of the posterior wall on the side of the posterior dislocation. Hip dislocations are an injury requiring careful trauma evaluation to rule out concomitant injuries. Time to presentation and, more importantly, reduction of a hip dislocation, is essential in treating this injury and preventing long-term complications, such as avascular necrosis and posttraumatic arthritis. The incidence, anatomy, mechanism of injury, treatment options, and long-term sequelae of hip dislocation, with literature review, are discussed.

  10. Low-energy anterior hip dislocation in a dancer.

    PubMed

    Stein, Drew A; Polatsch, Daniel B; Gidumal, Ramesh; Rose, Donald J

    2002-10-01

    In this article, we report the case of a healthy young woman who sustained an anterior hip dislocation while participating in a noncontact activity (ballet dancing). The patient's atraumatic dislocation failed closed reduction secondary to interposition of anterior capsule and rectus femoris muscle. Open reduction using a Smith-Petersen approach was concentric and stable. Postinjury femoral nerve neuropraxia resolved within 6 weeks. At 2-year follow-up, the patient was without complications of the injury-including avascular necrosis and posttraumatic arthritis. She returned to dancing and is now asymptomatic.

  11. Hip joint pain in spastic dislocation: aetiological aspects.

    PubMed

    Masłoń, Adrian; Jóźwiak, Marek; Pawlak, Maciej; Modrzewski, Tadeusz; Grzegorzewski, Andrzej

    2011-11-01

    Children with severe forms of cerebral palsy (CP) are at high risk of hip joint displacement. Various studies have found that the pain from affected joints occurs in 40 to 84% of studied individuals. The purpose of this study was to establish a correlation between the density of nociceptors localized in selected areas of the spastic dislocated hip joint and clinical evidence of hip joint pain in children with CP. Nineteen samples of articular capsule and 19 samples of teres ligaments, collected during open hip joint reduction from 19 non-ambulatory children with spastic CP (Gross Motor Function Classification System level V; mean age 9y 6mo; 10 males, nine females), were studied. Pain was assessed using the numeric rating scale completed by caregivers. The density of nociceptive fibres was compared between the children with painful and children with painless hip joints, using S-100 and substance P monoclonal antibodies. The presence of S-100 protein and substance P were significantly increased (p=0.024 and p=0.02 respectively) in the children with painful hip joints. There were significantly positive correlations between the intensity of pain and the density of nerve fibres with S-100 protein (teres ligament, p=0.001; joint capsule, p=0.032) as well as substance P (teres ligament, p=0.001). Direct and indirect inflammatory factors, present in dislocated hip joints with cartilage damage in children with spastic CP, lead to hip joint sensitization. © The Authors. Developmental Medicine & Child Neurology © 2011 Mac Keith Press.

  12. Central dislocation of the hip secondary to insufficiency fracture.

    PubMed

    Thaya, H Moe; Sivaloganathan, Sivan; Sankey, A; Gibbons, Charles E

    2010-03-20

    We present a case report of a 45-year old man who sustained a central dislocation of the hip secondary to an insufficiency fracture of the acetabulum. At the time of presentation he was on alendronate therapy for osteoporosis which had been previously investigated. CT scanning of the pelvis was useful for pre-operative planning which confirmed collapse of the femoral head but no discontinuity of the pelvis. The femoral head was morcellized and used as bone graft for the acetabular defect and an uncemented total hip replacement was performed.

  13. Central dislocation of the hip secondary to insufficiency fracture

    PubMed Central

    Thaya, H.Moe; Sivaloganathan, Sivan; Sankey, A; Gibbons, Charles E.

    2010-01-01

    We present a case report of a 45-year old man who sustained a central dislocation of the hip secondary to an insufficiency fracture of the acetabulum. At the time of presentation he was on alendronate therapy for osteoporosis which had been previously investigated. CT scanning of the pelvis was useful for pre-operative planning which confirmed collapse of the femoral head but no discontinuity of the pelvis. The femoral head was morcellized and used as bone graft for the acetabular defect and an uncemented total hip replacement was performed. PMID:21808700

  14. Three-dimensional computerized selection of hip prostheses in patients with congenital dislocated hips.

    PubMed

    Gelalis, L D; Xenakis, T A; Hantes, M; Vartziotis, K; Soucacos, P N

    2001-11-01

    This study assessed the effectiveness of the combined use of computed tomography (CT) and computer-aided design (CAD) in the preoperative evaluation and implant selection in 20 patients (20 hips) with congenital dislocation of the hip who were scheduled to undergo total hip arthroplasty. Computerized selection of the femoral implant with optimum fit and fill was made after a three-dimensional reconstruction of the femoral canal using CT data and CAD. Implantation of all sizes of 5 noncemented and 2 cemented femoral implants was simulated using CATIA software (IBM, Kingstone, NY). When patients underwent surgery, 18 of 20 preselected prostheses agreed by type and size with the prostheses implanted. The remaining 2 preselected implants agreed by type only. In patients with dislocated and dysplastic hips, combined use of CT and CAD allows effective preoperative planning by providing the surgeon with vital information about the proximal femoral canal geometry and the possible femoral implant with optimum fit and fill to be used.

  15. Cementless Total Hip Arthroplasty Involving Trochanteric Osteotomy without Subtrochanteric Shortening for High Hip Dislocation

    PubMed Central

    Lee, Soong Joon; Kim, Hee Joong

    2017-01-01

    Background Total hip arthroplasty with subtrochanteric shortening osteotomy is widely performed for high hip dislocation. However, suboptimal leg length discrepancy correction and nonunion of the osteotomy site remain concerns. Although total hip arthroplasty using trochanteric osteotomy without subtrochanteric osteotomy was introduced, cemented implants have been more commonly used than contemporary cementless implants in this procedure. We evaluated the long-term results of cementless total hip arthroplasty with trochanteric osteotomy without subtrochanteric osteotomy for high hip dislocation. Methods From 1990 to 2002, 27 cementless total hip arthroplasties using trochanteric osteotomy without subtrochanteric osteotomy were performed in 26 patients with Crowe III or IV high hip dislocation and a mean age of 36.4 ± 12.9 years. Seven ceramic-on-ceramic, 8 ceramic-on-polyethylene, 10 metal-on-polyethylene, and 2 metal-on-metal bearings were inserted. Mean follow-up was 15.1 ± 3.7 years. We retrospectively reviewed medical records and radiographic data and evaluated the clinical and radiological results including the Harris hip score, implant survival, correction of leg length discrepancy, and occurrence of complications. Results The mean Harris hip score and leg length discrepancy improved significantly from 73.3 to 94.9 points and from 4.3 cm to 1.0 cm, respectively. With revision for loosening set as the end point, implant survival rates at 10 and 15 years postoperatively were 96.0% and 90.9% for stems and 74.1% and 52.3% for cups. In 8 of 10 hips with the metal-on-polyethylene bearing and 4 of 8 hips with the ceramic-on-polyethylene bearing, revision surgery was performed for aseptic loosening. However, no revision was performed in hips with the ceramic-on-ceramic bearing or the metal-on-metal bearing. Implant survival was significantly different by the type of bearing surface. Two permanent neurologic complications occurred in patients with a limb lengthening

  16. Surgical hip dislocation in treatment of slipped capital femoral epiphysis

    PubMed Central

    Elmarghany, Mohammed; Abd El-Ghaffar, Tarek M.; Seddik, Mahmoud; Akar, Ahmed; Gad, Yousef; Ragheb, Eissa; Aprato, Alessandro; Massè, Alessandro

    2017-01-01

    Background: Most surgeons advocate in situ fixation of the slipped epiphysis with acceptance of any persistent deformity in the proximal femur [Aronsson DD, Loder RT, Breur GJ, Weinstein SL (2006) Slipped capital femoral epiphysis: current concepts. J Am Acad Orthop Surg 14, 666–679]. This residual deformity can lead to osteoarthritis due to femoroacetabular cam impingement (FAI) [Leunig M, Slongo T, Ganz R (2008) Subcapital realignment in slipped capital femoral epiphysis: surgical hip dislocation and trimming of the stable trochanter to protect the perfusion of the epiphysis. Instr Course Lect 57, 499–507]. Objective: The primary aim of our study was to report the results of the technique of capital realignment with Ganz surgical hip dislocation and its reproducibility to restore hip anatomy and function. Patients and methods: This prospective case series study included 30 patients (32 hips, 13 left (Lt) hips, 19 right (Rt) hips) with stable chronic slipped capital femoral epiphysis (SCFE) after surgical correction with a modified Dunn procedure. This study included 22 males and eight females. The mean age of our patients was 14 years (10–18 years). The mean follow-up period was 14.5 months (6–36 months). Results: Thirty hips had excellent and good clinical and radiographic outcomes with respect to hip function and radiographic parameters. Two patients had fair to poor clinical outcome including three patients who developed Avascular Necrosis (AVN). The difference between those who developed AVN and those who did not develop AVN was statistically significant in postoperative clinical scores (p = 0.0000). The mean slip angle of the femoral head was 52.5° ± 14.6 preoperatively and was corrected to a mean value of 5.6° ± 8.2° with mean correction of 46.85° ± 14.9° (p = 0.0000). The mean postoperative alpha angle was 51.15° ± 4.2° with mean correction of 46.70 ± 14.20 (p = 0.0000). In our series, the mean postoperative Harris hip

  17. Proximal femoral epiphysiolysis during reduction of hip dislocation in adolescents.

    PubMed

    Herrera-Soto, Jose Antonio; Price, Charles T; Reuss, Bryan L; Riley, Patrick; Kasser, James R; Beaty, James H

    2006-01-01

    Traumatic hip dislocation is an uncommon injury in children. The urgency of closed reduction to prevent possible osteonecrosis may present some pitfalls. Adolescents with open proximal femoral physis may have sustained trauma to the physis at the time of dislocation that can lead to displacement of the epiphysis during the reduction maneuver. The purpose of this study is to report 5 cases with this complication and discuss potential etiology and management. All of the 5 patients were between 12 and 16 years old and underwent closed reduction under conscious sedation. Epiphysiolysis of the femoral head was diagnosed after reduction in all 5 patients. Every patient underwent emergent open reduction and internal fixation of the femur and open hip reduction. Avascular necrosis was identified in all 5 patients within 3 to 15 months postinjury. If there is any suspicion of associated physeal injury or if there is any physeal instability noted under fluoroscopy, an open reduction is recommended in the operating room under radiograph guidance to prevent displacement.

  18. Cup Position Alone Does Not Predict Risk of Dislocation after Hip Arthroplasty

    PubMed Central

    Esposito, Christina I.; Gladnick, Brian P.; Lee, Yuo-yu; Lyman, Stephen; Wright, Timothy M.; Mayman, David J.; Padgett, Douglas E.

    2014-01-01

    Recent studies suggest the ‘Lewinnek safe zone’ for acetabular component position is outdated. We used a large prospective institutional registry to determine if there is a ‘safe zone’ exists for acetabular component position within which the risk of hip dislocation is low and if other patient and implant factors affect the risk of hip dislocation. Patients who reported a dislocation event within six months after hip replacement surgery were identified, and acetabular component position was measured with anteroposterior radiographs. The frequency of dislocation was 2.1% (147 of 7040 patients). No significant difference was found in the number of dislocated hips among the zones. Dislocators <50 years old were less active preoperatively than nondislocators (p=0.006). Acetabular component position alone is not protective against instability. PMID:25249516

  19. THA following deformities due to congenital dislocation of the hip joint.

    PubMed

    Macheras, George A; Koutsostathis, Stefanos D; Lepetsos, Panagiotis; Anastasopoulos, Panagiotis P; Galanakos, Spyridon; Papadakis, Stamatios A

    2014-10-02

    Total hip replacement is the treatment of choice for the patient suffering from end-stage hip osteoarthritis. Excellent long-term results have been published. In the presence of deformities due to congenital hip dislocation, total hip replacement is, in most of the cases, a difficult task, since the technique of performing such an operation is demanding and the results could vary. This paper presents our experience and preferred strategies focusing on challenges and surgical techniques associated with reconstructing the dysplastic hip.

  20. Late developmental dislocation of the hip after initial normal evaluation: a report of five cases.

    PubMed

    Raimann, Alfredo; Baar, Alejandro; Raimann, Roberto; Morcuende, Jose A

    2007-01-01

    Developmental dysplasia of the hip (DDH) denotes a wide spectrum of pathologies ranging from hip instability to frank dislocation. The current understanding is that cases of late diagnosis were missed during the newborn period. However, there is some evidence that a number of hip subluxations or dislocations may have been clinically stable in the neonatal period, but dislocate late. We present 5 cases of otherwise healthy children with normal physical examinations and hip radiographs in the first 3 months of life who later developed hip dislocations. Four of the 5 cases required surgical open reduction. In light of these cases and others in the literature, normal neonatal screening for DDH does not assure that continued normal development of the hip joint will happen. Our study confirms the existence of another entity in the wide spectrum of DDH: the late hip dislocation. Therefore, hip evaluations should be continued beyond the neonatal period until the child begins to walk. Parents should be informed that hip dislocation can occur in a late form, and they should be encouraged to take their children for repeated evaluations even if the neonatal screening is normal.

  1. Asymmetric Bilateral Hip Dislocations: A Case Report and Historical Review of the Literature

    PubMed Central

    Buckwalter, Joseph; Westerlind, Brian; Karam, Matthew

    2015-01-01

    Background Asymmetric bilateral hip dislocations are a rare injury pattern in which one hip dislocates posteriorly, and the contralateral hip dislocates anteriorly. We report a case of bilateral asymmetric hip dislocations and provide a comprehensive review of all available reports, identifying 104 total cases, which is 70 more than previously reported. Purpose To review and evaluate the total body of literature regarding bilateral asymmetric hip dislocations. Methods Comprehensive literature review and analysis of all reports of bilateral asymmetric hip dislocations with concurrent case report. Results and Conclusions Bilateral, asymmetric represent approximately 0.01%–0.02% of all joint dislocations. There has been a substantial increase in the number of case reports in the literature in the last 10 years. Males are more likely than females to incur this injury pattern and the most common mode of injury is motor vehicle accident Urgent closed reduction should be attempted in an efficient and safe manner to avoid potential complications, and open reduction should be considered in irreducible dislocations. Post reduction management should include stability assessment and CT to assess for associated injuries and intraarticular fragments; although no clear guidelines for post-reduction treatment emerged. Common complications include: nerve palsies, AVN and heterotopic ossification. PMID:26361448

  2. Gait analysis in low lumbar myelomeningocele patients with unilateral hip dislocation or subluxation.

    PubMed

    Gabrieli, Ana Paula T; Vankoski, Stephen J; Dias, Luciano S; Milani, Carlo; Lourenco, Alexandre; Filho, Jose Laredo; Novak, Robert

    2003-01-01

    The surgical indications for the treatment of unilateral hip dislocations or subluxations in patients with low lumbar myelomeningocele remain highly debatable. This study examines the influence of unilateral hip dislocation or subluxation on the gait of these patients using three-dimensional gait analysis. Twenty patients with a diagnosis of low lumbar myelomeningocele underwent three-dimensional gait analysis. All patients were community ambulators with solid ankle-foot orthoses and crutches who presented with unilateral hip dislocation or subluxation and no scoliosis. The patients were divided in two groups. Group 1 comprised 10 patients who demonstrated either no evidence of hip flexion or adduction contractures or symmetric hip contractures. Group 2 comprised 10 patients with unilateral hip flexion and/or adduction contractures. Pelvic and hip kinematics were assessed to determine the symmetry of motion between the involved and the noninvolved side during walking. Seven patients from group 1 walked with a symmetric gait pattern; only two patients from group 2 walked with a symmetric pattern. Gait symmetry corresponded to the absence of hip contractures or bilateral symmetrical hip contractures and had no relation to the presence of hip dislocation. The authors concluded that reduction of the hip is unnecessary.

  3. Protrusion of an artificial femoral head: a rare complication of chronic dislocation of the prosthetic hip.

    PubMed

    Kadar, Assaf; Gigi, Roy; Chechik, Ofir

    2013-02-01

    Chronic dislocation is considered a rare complication after total hip arthroplasty. We have treated a patient with a complication related to chronic dislocation-protrusion of the prosthetic femoral head through the skin. This 86-year-old bedridden patient with a known dislocated total hip arthroplasty presented with fever and protrusion of an artificial femoral head after 2 months of a nonhealing pressure sore. The care of this patient was partial removal of the prosthetic components and intravenous antibiotics. Chronic dislocation is rarely reported, yet it may cause severe complications in debilitated and demented patients. Special attention should be warranted to these patients as they might benefit from earlier surgical treatment.

  4. Epidemiology of traumatic hip dislocation in patients treated in Ceará, Brazil

    PubMed Central

    Lima, Luciana Cascão; do Nascimento, Robson Alves; de Almeida, Victor Monte Tenório; Façanha, Fernando Antônio Mendes

    2014-01-01

    OBJECTIVE: To describe the epidemiological profile of patients with traumatic hip dislocation treated in our Institute from November/2012 to July/2013. METHODS: A descriptive cross-sectional study based on interviews and involving 43 patients who suffered traumatic hip dislocation was conducted. RESULTS: The mean age of patients was 34.4 years old and 90.7% were male. Regarding the mechanism of injury, 95% involved traffic accidents. The posterior dislocation of the hip was the most common injury (93%). Associated lesions were observed in 74.4% of patients, hip fractures being the most frequent. The time span between accident and dislocation reduction was less than 6 hours in 37.2% of patients, between 6 and 12 hours in 32.5% and over 12 hours in 30.3%, ranging from 1 hour to 15 days. A fraction of 90.7% of patients was submitted to closed reduction. CONCLUSION: Traumatic hip dislocation affected mostly young adults, victims of traffic accidents. The posterior dislocation of the hip was the most frequent injury and closed reduction was performed in 90.7% of patients. The time span between accident and dislocation reduction was less than 12 hours in most patients. Level of Evidence III, Study of Nonconsecutive Patients. PMID:25061422

  5. A rare fracture-dislocation of the hip in a gymnast and review of the literature

    PubMed Central

    Mitchell, J. C.; Giannoudis, P. V.; Millner, P. A.; Smith, R. M.

    1999-01-01

    Posterior fracture-dislocation of the hip is an uncommon injury in athletics and leisure activities. It is more commonly seen in high energy motor vehicle accidents and occasionally in high energy sporting activities. A rare case is reported of posterior fracture-dislocation of the hip joint that occurred in a young athlete during gymnastics. This unusual mechanism of injury illustrates the great forces sustained by the hip joint of gymnasts. Early reduction and operative treatment led to a congruent and stable hip joint. After rehabilitation, she returned to light sporting activities after six months. 


 PMID:10450489

  6. Atraumatic posterior dislocation of the native hip: an unusual presentation of septic arthritis.

    PubMed

    Patel, N K; Windley, J; Naique, S

    2014-06-01

    We present a case of chronic posterior hip dislocation after severe joint destruction following septic arthritis. In the absence of trauma, infection must be considered in the differential diagnosis of a dislocated joint particularly in patients with risk factors such as intravenous drug abuse and immune compromise. Excision arthroplasty of the hip was performed with good pain relief and functional outcomes. This is an excellent temporary or permanent solution in managing such complex cases although alternative management options are discussed.

  7. Uncemented total hip arthroplasty in osteoarthritis of hip secondary to low and high dislocated hips: A mid-term follow-up study

    PubMed Central

    Munigangaiah, Sudarshan; O’Dwyer, Sinead; Masterson, Eric

    2016-01-01

    Background: Performing successful total hip replacement (THR) in dysplastic, subluxed, and dislocated hip is a challenging task. Here, we assessed midterm clinical and radiological outcomes of uncemented total hip arthroplasty in osteoarthritis (OA) of hip secondary to Hartofilakidis low and high-dislocated hips with a mean follow-up of 8.8 years. Materials and Methods: A retrospective study of prospectively collected data was designed involving all consecutive patients who underwent uncemented THR for OA of hip secondary to developmental dysplasia of the hip and Grade II or Grade III Hartofilakidis classification. Results: Thirty-two patients underwent 45 THR, with 23 Grade II (low dislocation) and 22 Grade III (high-dislocation) of Hartofilakidis classification. Thirteen patients had bilateral hip replacements, 19 patients had unilateral THR. There was highly statistically significant difference between preoperative and postoperative HHS and SF-36v2™ at each follow-up. Survivorship of original implant was 98.88% at a mean follow-up of 8.8 years. The mean improvement in leg length in this series was 3.6 cm (1.8-4.5, 95% confidence interval). No sciatic nerve or femoral nerve palsies were observed. Conclusions: Uncemented THR provides better function and quality of life. However, longer follow-up studies are needed to assess survivorship of uncemented THR in Hartofilakidis low and high-dislocations. PMID:27433063

  8. Surgical treatment of congenital dislocation of the hip.

    PubMed

    Tönnis, D

    1990-09-01

    The results of two collective studies on congenital dislocation of the hip (CDH) from a number of hospitals are reported here, including general trends in the Federal Republic of Germany and the author's personal methods and preferences. In the first collective study group, the rate of ischemic necrosis in open reductions was 8.2% for anterolateral approaches, 9.6% for inguinal, 16.7% for Ludloff's operation, and only 5.5% when shortening osteotomy was combined with open reduction. A simultaneous Salter osteotomy or acetabuloplasty increased the rate to 10.3% and a concomitant varus osteotomy to 22.2%. The author prefers an inguinal approach to the hip joint, first laterally and then medially of the iliopsoas muscle and femoral nerve, for optimal visualization of the acetabulum. Stability of the joint is increased by a girdle-like flap from the dorsolateral capsule, which is drawn anteriorly and prevents dorsal redislocation. Acetabuloplasty should also be used, even during the first year of life, in joints in which stability may only be guaranteed by extreme abduction and internal rotation. Salter's and Pemberton's osteotomies are used in Germany with good results. However, the author prefers a lateral Albee-Lance acetabuloplasty modified to a complete osteotomy for lateral levering of the acetabular roof. Long-term results show measurements between 82% and 93% of normal and slightly pathologic values. Simultaneous or single varus osteotomies lead to subcapital coxa valga and should no longer be used routinely. In adolescents and adults up to 45 years of age, as long as osteoarthritis is not too advanced and the femoral head is not too deformed, triple pelvic osteotomy with the author's type of modification has a number of advantages.

  9. Acetabular cartilage and labral damage observed during surgical hip dislocation for stable slipped capital femoral epiphysis.

    PubMed

    Sink, Ernest L; Zaltz, Ira; Heare, Travis; Dayton, Michael

    2010-01-01

    Surgical hip dislocation allows the surgeon full visualization of the proximal femur and acetabulum. It also makes it possible to directly observe the pathologic relationship between the proximal femur and acetabular rim with hip motion. The purpose of this study is to classify acetabular cartilage and labral damage that is present at the time of surgical hip dislocation for the treatment of symptomatic stable slipped capital femoral epiphysis (SCFE) hips. A retrospective study was performed at 2 North American centers on patients with a stable SCFE who had a surgical hip dislocation for chronic symptoms. The severity of SCFE (slip angle) was measured as mild (0-30 degrees), moderate (30-60 degrees), and severe (60-90 degrees). The degree of acetabular and labral damage was classified in each patient according to the Beck classification used for femoroacetabular impingement. Thirty-nine hips in 36 patients that underwent open surgical dislocation for diagnosis of stable SCFE were included. The breakdown of the radiographic severity of the SCFE was 8 mild, 20 moderate, and 11 severe. Labral injury was observed in 34 of 39 hips. Using the Beck classification for labral injury, there were 21 type 1 injuries, 9 type 2 injuries, and 4 type 3 injuries. Cartilage injury was present in 33 of 39 hips. Using Beck classification for cartilage damage, there were 6 grade 0, 5 grade 1, 10 grade 2, 4 grade 3, 10 grade 4, and 4 grade 5 injuries. The average depth of cartilage damage was 5 mm (range, 2-10 mm). In this study, significant chondromalacia and labral injury was observed in hips afflicted with SCFE. Surgical hip dislocation allowed direct confirmation of the impingement of the prominent metaphysis on the acetabular labrum and cartilage.

  10. [Asymmetric bilateral traumatic dislocation of the hip joint: a case report].

    PubMed

    Azar, Nikola; Yalçinkaya, Merter; Akman, Yunus Emre; Uzümcügil, Onat; Kabukçuoğlu, Yavuz S

    2010-08-01

    Bilateral traumatic dislocation of the hip is a rare condition. Simultaneous asymmetric traumatic dislocation of the hip, one hip anterior and the other posterior, is even more unusual. This article reports a 21-year-old male patient with asymmetric bilateral dislocation of the hip joint, injured due to a landslide during a canal excavation. The patient was treated conservatively and evaluated according to Thompson and Epstein clinical and radiographic criteria after a follow-up period of 10 years and six months. The clinical result was perfect and radiographical result was good. We determined that our case had occurred as a result of a mechanism that has not been previously published in the literature and evaluated it from this point of view.

  11. Nerve Palsy after Total Hip Arthroplasty without Subtrochanteric Femoral Shortening Osteotomy for a Completely Dislocated Hip Joint

    PubMed Central

    Sonohata, Motoki; Kitajima, Masaru; Kawano, Shunsuke; Mawatari, Masaaki

    2016-01-01

    Background: Neurological injuries are a rare but devastating complication after total hip arthroplasty (THA). The purpose of this study was to retrospectively determine the frequency of nerve palsy after THA without subtrochanteric femoral shortening osteotomy in patients with a completely dislocated hip joint without pseudo-articulation between the femoral head and iliac bone. Methods: Between October 1999 and September 2001, nine primary THAs were performed for patients with a completely dislocated hip joint. The limb lengths, neurological abnormalities, and the extent of their neurological recovery were evaluated. Three THAs were combined with subtrochanteric femoral shortening osteotomy, and six THAs were combined without subtrochanteric femoral shortening osteotomy. Results: The mean length of the operation was 4.8 cm (range, 3.0-6.5 cm). Sciatic nerve palsy developed in four of the nine patients after THA. None of the cases with sciatic nerve palsy were combined with subtrochanteric femoral shortening osteotomy. Three of four patients did not completely recover from sciatic nerve palsy. Conclusions: THA for patients with a completely dislocated hip was associated with a high risk of nerve palsy due to excessive limb lengthening; the potential for recovery from nerve palsy was observed to be poor. Subtrochanteric femoral shortening osteotomy should be used in combination with THA in patients with a completely dislocated hip. PMID:28217204

  12. Prognostic factors after a traumatic hip dislocation. A long-term retrospective study.

    PubMed

    Moreta, J; Foruria, X; Sánchez, A; Aguirre, U

    2017-09-06

    Traumatic hip dislocations can have devastating complications such as osteoarthritis or osteonecrosis. The aim of this study was to identify the variables and prognostic factors associated with clinical and radiological outcome after a traumatic hip dislocation at long-term follow-up. A review was performed of all dislocations and fracture-dislocations of the hip from January 1999 to December 2012. A computed tomography scan was performed after reduction in all cases. The Harris Hip Score and modified Merle-d'Aubigné-Postel method were used for clinical evaluation and radiological assessment was performed according to the Thompson and Epstein classification. There were 30 cases in 29 patients with a mean follow-up of 11 years (range, 4-17). The great majority were simple dislocations (21; 70%) vs. complex dislocations (9; 30%). Closed reduction was performed in less than 6h in all except one case (29; 96.7%). All of the patients with simple dislocations had an excellent outcome without radiological signs of osteoarthritis at the end of the follow-up (P<.01). Overall, arthritic signs had developed in 4 patients (13.3%) and avascular necrosis was noted in 3 patients (10%). Five patients with intraarticular fragments were treated non-operatively, and 3 of them developed arthritic changes (P<.05). Our study suggests that complex dislocations are associated with poorer functional and radiological outcomes than simple dislocations. We also found a strong association between intraarticular fragments and osteoarthritis, so surgical fragment removal could be considered in these cases. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Novel Technique for Femoral Head Reconstruction using Allograft following Obturator Hip Dislocation.

    PubMed

    Church, Dane J; Merrill, Haley M; Kotwal, Suhel; Dubin, Jonathan R

    2016-01-01

    Obturator hip dislocations with an associated osteochondral fracture of the femoral head are uncommon. The treatment of these injuries is challenging and the functional outcomes are poor. Though the injury pattern has been described previously in literature, there are few published reports regarding treatment options. This case report illustrates a novel technique for fixation and stabilization for an unusual injury involving an obturator hip dislocation and an osteochondral impaction fracture of the femoral head. A 30-years old African American male, involved in a motor vehicle collision, sustained an obturator dislocation of the left hip with a large posterior osteochondral fracture of the femoral head. An emergency closed reduction procedure was performed followed by a computed tomography (CT) scan of the hip joint which demonstrated a large osteochondral defect (25 x 10 mm, depth: 5 mm) of the femoral head, visualized within the weight-bearing area. Surgical intervention was planned as a fracture of the femoral head with a defect deeper than four millimeters has been shown to be a risk factor for the development of post-traumatic arthritis, often with onset of symptoms within 5 years of the date of injury. Following surgical hip dislocation, the defect of the femoral head was reconstructed with implantation of a femoral head allograft and internal fixation. At the six months follow-up, the patient could ambulate with minimal pain and without assistive devices. Radiographs demonstrated maintenance of articular congruity with no evidence of implant failure, post-traumatic arthritis or avascular necrosis. Surgical hip dislocation and reconstruction using femoral head allograft used to treat obturator hip dislocations with concomitant femoral head impaction fractures can lead to satisfactory short term functional outcomes.

  14. Novel Technique for Femoral Head Reconstruction using Allograft following Obturator Hip Dislocation

    PubMed Central

    Church, Dane J.; Merrill, Haley M.; Kotwal, Suhel; Dubin, Jonathan R.

    2016-01-01

    Introduction: Obturator hip dislocations with an associated osteochondral fracture of the femoral head are uncommon. The treatment of these injuries is challenging and the functional outcomes are poor. Though the injury pattern has been described previously in literature, there are few published reports regarding treatment options. This case report illustrates a novel technique for fixation and stabilization for an unusual injury involving an obturator hip dislocation and an osteochondral impaction fracture of the femoral head. Case Presentation: A 30-years old African American male, involved in a motor vehicle collision, sustained an obturator dislocation of the left hip with a large posterior osteochondral fracture of the femoral head. An emergency closed reduction procedure was performed followed by a computed tomography (CT) scan of the hip joint which demonstrated a large osteochondral defect (25 x 10 mm, depth: 5 mm) of the femoral head, visualized within the weight-bearing area. Surgical intervention was planned as a fracture of the femoral head with a defect deeper than four millimeters has been shown to be a risk factor for the development of post-traumatic arthritis, often with onset of symptoms within 5 years of the date of injury. Following surgical hip dislocation, the defect of the femoral head was reconstructed with implantation of a femoral head allograft and internal fixation. At the six months follow-up, the patient could ambulate with minimal pain and without assistive devices. Radiographs demonstrated maintenance of articular congruity with no evidence of implant failure, post-traumatic arthritis or avascular necrosis. Conclusion: Surgical hip dislocation and reconstruction using femoral head allograft used to treat obturator hip dislocations with concomitant femoral head impaction fractures can lead to satisfactory short term functional outcomes. PMID:27299126

  15. [Total hip arthroplasty for treatment of Crowe type IV congenital dysplasia of hip with dislocation in adults].

    PubMed

    Li, Wenbo; Zhang, Wenming; Bai, Guochang; Huang, Zida; Shen, Rongkai

    2013-10-01

    To study the effectiveness and acetabular prosthesis selection of the total hip arthroplasty (THA) for Crowe type IV congenital dysplasia of the hip with dislocation in adults. Between June 2008 and May 2012, 8 adult patients (8 hips) with Crowe type IV congenital dysplasia of the hip with dislocation underwent THA. They were all female, aged 20-35 years with a mean age of 25 years. The left hip was involved in 5 cases and the right hip in 3 cases. The Harris score of involved hip was 53.9 +/- 6.6. The shortened length of involved extremity was 4-6 cm (mean, 4.8 cm). The X-ray films showed complete dislocation in all cases. The acetabular prosthesis with diameter of 42-44 mm and S-ROM femoral prosthesis were used in THA. The incisions healed by first intention. There was no hip dislocation events and sciatic nerve injury during the follow-up. Femoral nerve injury occurred in 1 case and asymptomatic venous thrombosis of the leg muscle occurred in 2 cases. All the patients were followed up 1-5 years (mean, 3 years). All cases showed obvious improvement of claudication and could restore to work. At 6 months after operation, the mean length difference between affected and contralateral extremities was 0.4 cm (range, 1.0-0.6 cm); the Harris score was significantly increased to 87.6 +/- 0.3 (t = 1.77, P = 0.00). The X-ray films showed that all cases got bony union at 3-6 months after operation and stable interface between acetabular prosthesis and bone. No revision was involved during the follow-up. THA with small acetabular cup and subtrochanteric osteotomy is an effective method in the treatment of Crowe type IV congenital dysplasia of the hip with dislocation in adults. The early effectiveness is satisfactory. The long-term survival rate of prosthesis needs to be followed up.

  16. Long-term follow-up of open reduction surgery for developmental dislocation of the hip.

    PubMed

    Holman, Joel; Carroll, Kristen L; Murray, Kathleen A; Macleod, Lynne M; Roach, James W

    2012-03-01

    We posed 2 questions: what is the long-term result of open reduction surgery in developmental dysplasia of the hip, and is there an age at surgery above which the outcome was too poor to recommend the operation? Between 1955 and 1995, 148 patients with 179 dislocated hips had open reduction surgery for developmental dysplasia of the hip (141 anterior and 38 Ludloff medial approaches). We attempted to locate all 148 patients for the follow-up evaluation. Fifty-three patients (36%) with 66 hips (37%) were located and participated in the study. These 66 hips represented 34% of the anterior open reductions and 47% of the Ludloff medial reductions. Twenty-two of the 66 hips had Severin IV or worse outcomes and included 7 with total hip arthroplasties and 2 with hip fusions. Age at surgery was significantly lower for Severin I, II, and III, compared with Severin IV and above (P=0.003, 0.001, 0.003) with outcomes deteriorating substantially after age 3. Approximately half of the hips required further surgery for dysplasia. All hips that sustained osseous necrosis had Severin IV or worse outcomes, and hips that redislocated and required revision surgery only achieved Severin I or II ratings 18% of the time. Nine "normal" hips became dysplastic and 3 had pelvic osteotomies as teenagers. Two other normal hips developed osseous necrosis during treatment of the contralateral hip. Results deteriorate as the age at surgery increases. Osseous necrosis and redislocation predict a poor functional and radiographic result. The "normal" hip may develop insidious dysplasia and also may be injured during treatment of the involved hip. Above age 3, some patients may not have sufficient acetabular growth to remodel a surgically reduced hip. Level IV--case series.

  17. An Unusual Traumatic Presentation: Luxatio Erecta Humeri and Concomitant Hip Dislocation

    PubMed Central

    Anarat, Berkan; Ersin, Mehmet; Erşen, Ali; Şen, Cengiz

    2016-01-01

    Introduction. Inferior dislocation of the glenohumeral joint, known as luxatio erecta humeri, and posterior hip dislocation are both rare presentations in the emergency department. The most common aetiology is falling for luxatio erecta humeri. The aim of this manuscript was to present a unique case in terms of luxatio erecta humeri, which has a different aetiology, treatment method, and concomitant injury. Presentation of Case. We report a construction worker who was rescued from a collapsed building who presented with both luxatio erecta humeri and complex posterior hip dislocation. An orthopaedic surgeon reducted luxatio erecta humeri with a one-step reduction technique under procedural anaesthesia as soon as the patient's vital signs were stable. Discussion. Different concomitant injuries and various injury mechanisms have been described in regard to inferior shoulder dislocation in the literature. However, posterior dislocation of the hip as a concomitant distant region injury and trapping as an injury mechanism for luxatio erecta humeri are being described for the first time in this case report. Two reduction manoeuvers, one-step and two-step, have been used for this dislocation. Some authors suggested that a two-step manoeuver can be more easy to apply. In our specific case, luxatio erecta was easily reducted by a single operator in a single attempt. Conclusion. Luxatio erecta humeri may occur from trapping and complex injuries can accompany luxatio erecta humeri in patients with multiple trauma. A one-step closed reduction can be easily applied by a single operator under procedural anaesthesia. PMID:28078152

  18. Can posterior hip fracture-dislocation occur in indoor football (futsal)? A report of two cases.

    PubMed

    Yasin, Faissal Nor; Singh, Vivek Ajit

    2009-01-01

    Hip fracture-dislocation is extremely rare in sports and is most frequently seen after road traffic accidents. This injury is associated with considerable long-term disability and rapidly progressive joint degeneration. This case report illustrates two cases of hip fracture dislocation that occurred while playing recreational indoor football (futsal). Futsal is a fast-emerging recreational sport in Malaysia and we are now beginning to see high-impact injuries rarely encountered in recreational sports. Therefore, futsal cannot be taken lightly and it is important to take adequate precautions to prevent serious injuries when participating in such sports.

  19. Diagnosis of Developmental Dislocation of the Hip by Sonospectrography

    PubMed Central

    Korkusuz, Feza

    2008-01-01

    Because not all infants can be screened for DDH by experts, early diagnosis of developmental dysplasia of the hip (DDH) by primary health care professionals is important. We developed a broadband electroacoustic sound transmission-detection (sonospectrography) system and explored its utility in 22 patients (average age, 5.9 years; range, 0.3–14 years) with unilateral DDH in this preliminary study. Distinct from ultrasonography, the sonospectrography system functions by sound transmission and recording through tissues to differentiate between normal and abnormal hips. All hips were examined at four different hip and knee positions. The normal hip served as the control. The sonospectrography system was able to detect unilateral DDH. Dysplastic hips had lower sound transmission values when compared to normal hips in all patients and all four positions; however, the highest (X = 88.8 ± 30.2 Hz) and lowest (X = 8.3 ± 5.4 Hz) sound transmission mean values were obtained at different positions in the normal hips and those with DDH. Sound transmission values of dysplastic hips were always lower than that of normal hips when the hip and knee was flexed during measurements. Sound transmission values decreased with age. The sonospectrography system may offer a new noninvasive method in the diagnosis of unilateral DDH but requires further study of sensitivity and specificity of detecting dysplastic hips without subluxation in newborn infants. Level of Evidence: Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18274713

  20. OPEN REDUCTION OF HIP DISLOCATION IN PATIENTS WITH ARTHROGRYPOSIS MULTIPLEX CONGENITA – AN ANTEROMEDIAL APPROACH

    PubMed Central

    Rocha, Luis Eduardo Munhoz da; Nishimori, Fábio Koiti; Figueiredo, Daniel Carvalho de; Grimm, Dulce Helena; Cunha, Luiz Antonio Munhoz da

    2015-01-01

    To evaluate the results from surgical treatment of hip dislocation through the anteromedial approach, in patients with arthrogryposis multiplex congenita (AMC). Methods: The medical files and radiographs of seven children with AMC who presented hip dislocation (total of 10 dislocated hips) were retrospectively reviewed. Pre and postoperative joint mobility was evaluated by summing the joint range of motion in flexion and abduction. The acetabular angle and height of the femoral neck before the operation, and the continuity of the Shenton arc, Sharp angle and center-edge (CE) angle after the operation, were evaluated radiographically. When avascular necrosis was identified, it was classified in accordance with Ogden and Bucholz. Results: The mean age of the children at the time of the surgery was 5.5 months (range: 3 to 11 months). The mean duration of follow-up for the patients was 9.5 years (range: 2 to 13 years). The mean amplitude of the sum of the joint range of motion in flexion and abduction in the preoperative examination was 108° (range: 70° to 155°) and postoperatively, it was 125° (range: 75° to 175°). In the last evaluation, eight hips were found to be centered and two were subluxated. Two hips had been subjected to Salter iliac osteotomy. Two hips (20%) had presented significant signs of Ogden type IV avascular necrosis. Eight hips had good results while two were fair. Conclusion: We consider that the anteromedial approach is a good option for treating hip dislocation in very young patients with arthrogryposis multiplex congenita. PMID:27022586

  1. Acetabular cup position and risk of dislocation in primary total hip arthroplasty

    PubMed Central

    Seagrave, Kurt G; Troelsen, Anders; Malchau, Henrik; Husted, Henrik; Gromov, Kirill

    2017-01-01

    Background and purpose — Hip dislocation is one of the most common complications following total hip arthroplasty (THA). Several factors that affect dislocation have been identified, including acetabular cup positioning. Optimal values for cup inclination and anteversion are debatable. We performed a systematic review to describe the different methods for measuring cup placement, target zones for cup positioning, and the association between cup positioning and dislocation following primary THA. Methods — A systematic search of literature in the PubMed database was performed (January and February 2016) to identify articles that compared acetabular cup positioning and the risk of dislocation. Surgical approach and methods for measurement of cup angles were also considered. Results— 28 articles were determined to be relevant to our research question. Some articles demonstrated that cup positioning influenced postoperative dislocation whereas others did not. The majority of articles could not identify a statistically significant difference between dislocating and non-dislocating THA with regard to mean angles of cup anteversion and inclination. Most of the articles that assessed cup placement within the Lewinnek safe zone did not show a statistically significant reduction in dislocation rate. Alternative target ranges have been proposed by several authors. Interpretation— The Lewinnek safe zone could not be justified. It is difficult to draw broad conclusions regarding a definitive target zone for cup positioning in THA, due to variability between studies and the likely multifactorial nature of THA dislocation. Future studies comparing cup positioning and dislocation rate should investigate surgical approach separately. Standardized tools for measurement of cup positioning should be implemented to allow comparison between studies. PMID:27879150

  2. Traumatic posterior hip dislocation and ipsilateral distal femoral fracture in a 22-month-old child: a case report.

    PubMed

    Ciftdemir, Mert; Aydin, Deniz; Ozcan, Mert; Copuroglu, Cem

    2014-11-01

    Minor trauma may cause hip dislocation in young children because of physiologic hip joint laxity and the soft cartilaginous structure of the acetabulum. In this work, we report on a 22-month-old boy with right-sided traumatic posterior hip dislocation and ipsilateral distal femoral fracture because of an outdoor motor vehicle accident. The patient was treated with emergency closed reduction and one and a half hip spica under general anaesthesia. The femoral fracture and hip dislocation were healed smoothly without any complication. Traumatic hip dislocation is rare in children, which may occur after trivial trauma. Prognosis is better in younger patients with low-energy trauma and in cases treated early.

  3. Rocket launcher: A novel reduction technique for posterior hip dislocations and review of current literature.

    PubMed

    Dan, Michael; Phillips, Alfred; Simonian, Marcus; Flannagan, Scott

    2015-06-01

    We provide a review of literature on reduction techniques for posterior hip dislocations and present our experience with a novel technique for the reduction of acute posterior hip dislocations in the ED, 'the rocket launcher' technique. We present our results with six patients with prosthetic posterior hip dislocation treated in our rural ED. We recorded patient demographics. The technique involves placing the patient's knee over the shoulder, and holding the lower leg like a 'Rocket Launcher' allow the physician's shoulder to work as a fulcrum, in an ergonomically friendly manner for the reducer. We used Fisher's t-test for cohort analysis between reduction techniques. Of our patients, the mean age was 74 years (range 66 to 85 years). We had a 83% success rate. The one patient who the 'rocket launcher' failed in, was a hemi-arthroplasty patient who also failed all other closed techniques and needed open reduction. When compared with Allis (62% success rate), Whistler (60% success rate) and Captain Morgan (92% success rate) techniques, there was no statistically significant difference in the successfulness of the reduction techniques. There were no neurovascular or periprosthetic complications. We have described a reduction technique for posterior hip dislocations. Placing the patient's knee over the shoulder, and holding the lower leg like a 'Rocket Launcher' allow the physician's shoulder to work as a fulcrum, thus mechanically and ergonomically superior to standard techniques. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  4. Open anterior dislocation of the hip in an adult: a case report and review of literature.

    PubMed

    de Oliveira, Anderson Luiz; Machado, Eduardo Gomes

    2014-01-01

    Open anterior hip dislocation is a rare condition and results from high-energy trauma. Ten cases of open anterior dislocation have been described in the literature so far. Its rarity is due to the inherent stability of the joint, its deep position in the pelvis, with strong ligaments and bulky muscles around the articulation. Several factors influence the prognosis, such as the degree of compounding, the associated soft tissue injuries, the age of the patient and, mainly, the delay in reduction. The main complications are: arthrosis of the hip, with incidence of 50% of cases, when associated with fractures of the femoral head; and osteonecrosis of the femoral head, with incidence between 1.7 and 40% (in closed anterior dislocation). Because of the rarity and the potential disability of this lesion, we report a case in a 46-year-old man, involved in an automobile accident. The hip was reduced (anterior superior dislocation) in the first three hours of the trauma. The patient was kept non-weight bearing until sixth week, with complete weight bearing after 10th week. After one year follow-up, the functional result was poor (Harris Hip Score: 52), probably because of the associated labral tear, but without signs of osteonecrosis of the femoral head in magnetic resonance imaging.

  5. Weaver syndrome associated with bilateral congenital hip and unilateral subtalar dislocation

    PubMed Central

    Mikalef, P; Beslikas, T; Gigis, I; Bisbinas, I; Papageorgiou, T; Christoforides, I

    2010-01-01

    Background: Weaver syndrome is a congenital paediatric syndrome characterized by mental, respiratory and musculoskeletal manifestations. The coexisting deformities of the skull, the face, fingers and toes are typical. We report a case of a girl with Weaver syndrome associated with rare bilateral congenital dislocation of the hips associated with congenital hypoplastic talus and subtalar dislocation of her ankle joint. Case Report: A 3-year old girl was admitted in our department with typical manifestations of Weaver syndrome, associated with congenital dislocation of bilateral hips, hypoplastic talus and subtalar dislocation of her right ankle. She was in pain while standing upright and incapable of independent walking. Both hips were treated operatively with open reduction and bilateral iliac osteotomy. Two years afterwards she had an open reduction of her talus and extraarticular arthrodesis of her subtalar joint in her right ankle. Six years postoperatively after the hip operations and four years after the ankle operation the girl is ambulant with a painless independent and unaided walking with a mild limp and full range of movements in all the operated joints. Conclusions: We suggest that children with Weaver syndrome and disabling musculosceletal deformities, particularly affecting their ability to stand up and walk should be treated early, before bone maturity, in order to achieve the best potential musculoskeletal as well as developmental outcome. PMID:20981173

  6. Relation Between Side of Plagiocephaly, Dislocation of Hip, Scoliosis, Bat Ears, and Sternomastoid Tumours

    PubMed Central

    Watson, Geoffrey H.

    1971-01-01

    A relation is described between plagiocephaly and four structural lesions in children who have two or more of these five features. The flat temple in plagiocephaly, a unilateral congenitally dislocated hip, a scoliotic convexity in a young child, and a sternomastoid tumour tend to be on the same side, and a unilateral bat ear on the opposite side. PMID:5576031

  7. [Risk factors for total hip arthroplasty dislocation and its functional outcomes].

    PubMed

    Sanz-Reig, J; Lizaur-Utrilla, A; Miralles-Muñoz, F

    2015-01-01

    To evaluate risk factors for dislocation after primary total hip arthroplasty (THA), and its functional outcomes. A retrospective study was conducted on 22 cases with dislocation and 431 controls without dislocation, all performed with lateral access. The data were collected prospectively with a minimum follow-up of 5 years. Patient related factors, from primary surgery, and position of components on simple radiographs were analyzed. Harris and Merle D'Aubigné hip scores, and short Womac questionnaire were used. Demographic, patient-related or surgical technique factors were not risk predictors of dislocation. With regard to position of components, an acetabular abduction >50° (p = 0.003) and anteversion lower or higher than 10°- 20° (p = 0.044) were risk factors. Controls and dislocation treated conservatively had similar outcomes, and in both were better than in those treated with surgical revision (p = 0.03). Factors relating to the patient and soft tissues status may influence the stability of the arthroplasty, but malposition of the acetabular component seems to be the most important and common risk factor for dislocation. Copyright © 2014. Published by Elsevier Espana.

  8. THE INFLUENCE OF THE SURGICAL APPROACH CONCERNING DISLOCATION IN TOTAL HIP ARTHROPLASTY

    PubMed Central

    Vicente, José Ricardo Negreiros; Pires, André Fernandes; Lee, Bruno Takasaki; Leonhardt, Marcos Camargo; Ejnisman, Leandro; Croci, Alberto Tesconi

    2015-01-01

    Objectives: Our primary aim was to evaluate the occurrence of dislocation of non-cemented total hip arthroplasty, when using the posterior and the direct lateral approaches. Methods: We performed a comparative retrospective study with 232 patients submitted to non-cemented total hip arthroplasty, due to the diagnosis of primary or secondary osteoarthritis. The posterior approach was used in 105 patients while direct lateral approach was used in 127 patients. There was only one prosthesis model and the same rehabilitation program and post-operative care was used for all patients. We checked the occurrence of dislocation, the acetabular positioning and also the size of the components. Results: There was only one case of dislocation, treated with closed reduction successfully. This was a 47 year-old female, submitted to direct lateral approach. The mean follow-up time for both groups was 23.7 months, ranging from six to 42 months. Conclusion: The authors conclude that the prevalence of total hip arthroplasty dislocation is similar for both approaches, and educational measures besides the use of a higher femoral offset seem to reduce the risk of this complication. PMID:27077060

  9. Dislocation

    MedlinePlus

    Joint dislocation ... It may be hard to tell a dislocated joint from a broken bone . Both are emergencies that ... to repair a ligament that tears when the joint is dislocated is needed. Injuries to nerves and ...

  10. Computed tomography arthrography in traumatic hip dislocation. Intra-articular and capsular findings.

    PubMed

    Glynn, T P; Kreipke, D L; DeRosa, G P

    1989-01-01

    The newer diagnostic modalities such as computed tomography and magnetic resonance imaging are becoming increasingly used in the evaluation of joint trauma. The combination of computed tomography and arthrography can also be of significant diagnostic value in certain specific situations. In our case report, we describe its use in post-traumatic recurrent hip dislocation and its value, not only in depicting a posterior capsular tear, but also in the diagnosis of an internal joint derangement which may contribute to incongruous reduction of the hip joint.

  11. Short-term results of early (before 6 months) open reduction of dislocated hips in arthrogryposis multiplex congenita.

    PubMed

    Aydin, Bahattin K; Yilmaz, Guney; Senaran, Hakan; Durgut, Fatih

    2016-11-01

    The aim of this study was to report the results of early open reduction of hip dislocations in infants with arthrogryposis multiplex congenita. Seven patients who were under 6 months of age at the time of hip reduction, with a mean follow-up period of 47.5±11.3 months after surgery, were included in this study. Four of seven patients (six of 13 hips) required additional hip surgeries during their follow-up. The short-term results of early open reduction of hips were not promising as most of the patients required additional hip surgeries.

  12. Pseudo-Acetabulum due to Heterotopic Ossification in a Child with Post Traumatic Neglected Posterior Hip Dislocation

    PubMed Central

    Pathak, Aditya C; Patil, Atul K; Sheth, Binoti; Bansal, Rohan

    2012-01-01

    Introduction: Traumatic neglected dislocations of hip in children are rare entity. Neglected traumatic dislocations of hip in children along with heterotopic ossification are still rare. Post traumatic neglected hip dislocations are to be diagnosed as early as possible and have to be treated with precision and aggression as the outcome of treatment for the same is not predictable. Case Report: 5 year female with post-traumatic neglected hip dislocation with heterotopic ossification forming a pseudoacetabulum postero-superiorly in which femur head was lodged. The girl was operated by open reduction using Moore’s Posterior approach and showed good results. Here is a mention of a rare case with a good 18 months follow up with no complication. Conclusions: Post-traumatic neglected posterior hip dislocation mostly requires open reduction and relocation of femoral head in original acetabulum with concentric reduction. Heterotopic ossification is a rare but known complication of traumatic dislocation of hip in children. Good results can be achieved in such cases and regular follow-up of patient is required post-operatively.

  13. TRAUMATIC POSTERIOR DISLOCATION OF THE HIP IN CHILDREN:REPORT ON FIVE CASES

    PubMed Central

    Brandão, Gilberto Francisco; Américo, Luiz Renato Drumond; Soares, Cláudio Beling Gonçalves; Faria, Rodrigo Galinari Costa; Teixeira, Luiz Eduardo Moreira

    2015-01-01

    Objective: To evaluate a series of cases of traumatic posterior dislocations in children, with the treatment and results, and to review issues relating to the epidemiology, clinical and radiographic diagnosis, treatment, complications and prognosis of such cases. Methods: Five patients with traumatic hip dislocation, with a mean age of 4.6 ± 0.9 years and a follow-up period of 19.8 ± 7.0 months, were evaluated retrospectively. The time elapsed between dislocation and reduction, the type of treatment, the associated injuries and the subsequent complications were evaluated. Results: The initial treatment was closed reduction, which was performed on average 5.2 ± 3.6 hours after the initial trauma. All the patients underwent the reduction under anesthesia. The complementary treatment included plaster cast immobilization and traction. No need for additional surgery was observed and there were no long-term side effects. Conclusion: Traumatic dislocation of the hip should be treated quickly by means of closed reduction, with appropriate control over the reduction and rigorous observation in order to diagnose and treat late complications. PMID:27022542

  14. Computer modeling of the pathomechanics of spastic hip dislocation in children.

    PubMed

    Miller, F; Slomczykowski, M; Cope, R; Lipton, G E

    1999-01-01

    Spastic muscles about the hip cause subluxation, dislocation, and lead to acetabular dysplasia. Spastic hip disease occurs when the muscles about the hip exert forces that are too high or in the wrong direction or both. To determine the role of the hip forces in the progression of spastic hip disease and the effect of both muscle-lengthening and bony reconstructive surgeries, a computerized mathematical model of a spastic hip joint was created. The magnitude and direction of the forces of spastic hips undergoing surgery were analyzed preoperatively and postoperatively to determine which procedure is best suited for the treatment of spastic hip disease. The muscle-lengthening procedures included (a) the adductor longus, (b) the psoas, iliacus, gracilis, adductor brevis, and adductor longus, and (3) the psoas, iliacus, gracilis, adductor brevis, adductor longus, semimembranosus, and semitendinosus. The bony reconstructive and muscle-lengthening procedures included (a) lengthening the psoas, iliacus, gracilis, adductor brevis, adductor longus, semimembranosus, and semitendinosus combined with changing femoral neck anteversion from 45 to 10 degrees , (b) lengthening of the psoas, iliacus, gracilis, adductor brevis, adductor longus, semimembranosus, and semitendinosus combined with changing neck-shaft angle from 165 to 135 degrees , and (c) lengthening of the psoas, iliacus, gracilis, adductor brevis, adductor longus, semimembranosus, and semitendinosus combined with changing femoral neck anteversion from 45 to 10 degrees and neck-shaft angle from 165 to 135 degrees . Results show that a child with spastic hip disease has a hip-force magnitude 3 times that of the a child with a normal hip in the normal physiologic position. Based on this mathematical model the best to normalize the magnitude of the hip-joint reaction force, the muscles to be lengthened should include the psoas, iliacus, gracilis, adductor brevis, and the adductor longus. To normalize the direction of

  15. Traumatic hip dislocation with incomplete reduction due to soft-tissue interposition in a 4-year-old boy.

    PubMed

    Burgos, J; Gonzalez-Herranz, P; Ocete, G

    1995-01-01

    The case of a traumatic dislocation of the left hip in a 4-year-old boy is presented. After an initial attempt at reduction under general anesthesia, a permanent deformity in the flexion of the hip remained, and there was radiographic evidence of a nonconcentric reduction. Computed tomography (CT) showed interposition in the posterior part of the joint. Under general anesthesia, the mobilization of the hip reduced the dislocation correctly, removing the necessity of open treatment. This case stresses the need for early diagnosis of this serious complication and closed reduction of the joint, avoiding the poor results of open and deferred treatments.

  16. Dislocation

    MedlinePlus

    ... Dislocations can occur in contact sports, such as football and hockey, and in sports in which falls ... downhill skiing, gymnastics and volleyball. Basketball players and football players also commonly dislocate joints in their fingers ...

  17. Posterior dislocation of hip with ipsilateral intertrochanteric fracture: A report of two cases

    PubMed Central

    Ul Haq, Rehan; Kumar, Jaswant; Dhammi, IK; Jain, Anil K

    2016-01-01

    Posterior dislocations of the hip are known to be associated with fractures of the femoral head, neck, shaft, or posterior acetabular wall. However, its association with ipsilateral intertrochanteric fracture has only been anecdotally described in the English literature. We report two such cases managed by open reduction (OR) of the hip and internal fixation (IF) of the intertrochanteric fracture. The first case was a 26-year-old male who was managed by OR of the hip with IF of the intertrochanteric fracture with a dynamic hip screw and had a good functional result at 1-year followup. The second case was a 36-year-old female who was also managed by OR of the hip with IF of the head fragments with Herbert screw and IF of the intertrochanteric fracture with a dynamic condylar screw. The patient had a fair, functional result at 1-year followup. With the increase in high energy trauma, these fracture patterns have become more common, and there is an urgent need to review the existing classifications so that these fractures are better categorized, and treatment guidelines defined. PMID:27746503

  18. Secondary avascular necrosis after treatment for congenital dislocation of the hip.

    PubMed

    Burgos, J; Gonzalez-Herranz, P; Ocete, G; Rapariz, J M

    1995-01-01

    We made a radiographic study of 104 unilateral congenital dislocations of the hip (CDH) that had an average age of 12 months (range 4-24), were treated with the same therapeutic protocol, and had an average six years follow-up (range 3-13). Radiographic changes were evident in the proximal femoral epiphysis in 57 hips (55%). In 7 (7%) the changes consisted of central osteoporosis with a cystic aspect, without metaphyseal or physeal changes, and had a normal end result without sequelae. This group was classified as type I. Fifty hips (48%) that were type II showed epiphyseal changes consisting of trabecular rarefaction with osteoporosis and irregular sclerosis, followed by a decrease of epiphyseal height and trabecular recovery. Forty-two hips (40%) were type IIA, with < 75% decrease in epiphyseal height with respect to the healthy side; five of these had a normal evolution, 35 had coxa magna and/or decrease of epiphyseal height, and only two cases had physeal lesion. In type IIB, hips, with > 75% decrease of epiphyseal height, 8 cases (8%) had a final physeal lesion.

  19. Bilateral pathological dislocation of the hip secondary to tuberculous arthritis following disseminated tuberculosis: a case report and review of the literature.

    PubMed

    Tahasildar, Naveen; Sudesh, Pebam; Tripathy, Sujit Kumar; Shashidhar, B K

    2012-11-01

    Pathological dislocation of the hip has been reported as a complication in various hip disorders. Several pathomechanisms including capsular laxity, synovial hypertrophy, and acetabular and proximal femur destruction have been described. We report a case of bilateral pathological dislocation of the hip in a 6-year-old girl secondary to tuberculous arthritis following disseminated tuberculosis, which we managed operatively. At the 18-month follow-up, the child had a clinically stable left hip despite radiological subluxation. Bilateral pathological dislocation of the hip associated with tuberculous arthritis is a rare condition and has never been reported in the literature.

  20. Surgical Dislocation in the Management of Pediatric and Adolescent Hip Deformity

    PubMed Central

    Rebello, Gleeson; Spencer, Samantha; Millis, Michael B.

    2008-01-01

    The surgical dislocation approach is useful in assessing and treating proximal femoral hip deformities commonly due to pediatric conditions. We sought to demonstrate the efficacy and problems associated with this technique. Diagnoses included slipped capital femoral epiphysis, Perthes disease, developmental dysplasia of the hip, osteonecrosis, and exostoses. Through this approach, femoral head-neck osteoplasty (22), intertrochanteric osteotomy (eight), femoral head-neck osteoplasty plus intertrochanteric osteotomy (15), femoral neck osteotomy (five), open reduction and internal fixation of an acute slipped capital femoral epiphysis with callus resection (five), open reduction and internal fixation of an acetabular fracture (one), trapdoor procedure (one), and acetabular rim osteoplasty (one) were performed. The average patient age was 16 years. The minimum followup was 12 months (average, 41.6 months; range, 12–73 months). Patients with Perthes disease and SCFE had preoperative and postoperative WOMAC scores of 9.6 and 5.1, and 7.9 and 3.5 respectively. In patients with unstable SCFEs, the average postoperative WOMAC score was 1.2. Seven patients underwent THAs and two patients underwent hip fusion. Complications in the 58 procedures included four cases of osteonecrosis: three after femoral neck osteotomy and one after intertrochanteric osteotomy. The surgical dislocation technique can be utilized to effectively treat these deformities and improve short-term symptoms. Although the technique is demanding, we believe surgical dislocation offers sufficient advantages in assessing and treating these complex deformities that it justifies judicious application. Level of Evidence: Level IV, retrospective study, case series. See the Guidelines for Authors for a complete description of levels of evidence. PMID:19002743

  1. Lower Limbs Alignment in Patients with a Unilateral Completely Dislocated Hip

    PubMed Central

    Someya, Shinsuke; Sonohata, Motoki; Ide, Shuya; Nagamine, Satomi; Tajima, Tomonori; Mawatari, Masaaki

    2016-01-01

    Background: Severe hip osteoarthritis is known to lead to secondary osteoarthritis of the knee joint. It is not clear whether contracture or a leg length discrepancy is more important in determining the knee alignment. Methods: In this study, 48 hips in 48 patients with a unilateral completely dislocated hip (Crowe IV) were recruited. The patients were divided into two groups (Crowe IVa and IVb). The Crowe IVa group had completely dislocation with psudo-articulation, and the Crowe IVb group had completely dislocation without psudo-articulation. The lower limb alignment was divided into three patterns according to the femorotibial angle; varus (≥176 degrees), neutral(170 to 175 degrees) and valgus(≤169 degrees). Results: The combination of valgus alignment on the affected side and varus alignment on the unaffected side, so-called “windswept deformity” was observed in 12.5% of the patients; this included 18.2% and 7.7%, in the Crowe IVa and Crowe IVb groups, respectively. The valgus alignment on the unaffected side, namely “long leg arthropathy,” was found to have occurred in 6.3% of the patients, including 13.6% of the patients in the Crowe IVa group; there were no cases of long “leg arthropathy” in the Crowe IVb group. Conclusion: The lower limb alignment on the unaffected side had a tendency to be varus in the Crowe IV patients. The “windswept deformity” was observed in each of the groups; however, “long leg arthropathy” was only found in the Crowe IVa group. PMID:27733883

  2. Anesthesia for a patient with Fanconi anemia for developmental dislocation of the hip: a case report.

    PubMed

    Dogan, Zafer; Yildiz, Huseyin; Coskuner, Ismail; Uzel, Murat; Garipardic, Mesut

    2014-01-01

    Fanconi anemia is a rare autosomal recessive inherited bone marrow failure syndrome with congenital and hematological abnormalities. Literature regarding the anesthetic management in these patients is limited. A management of a developmental dislocation of the hip was described in a patient with fanconi anemia. Because of the heterogeneous nature, a patient with fanconi anemia should be established thorough preoperative evaluation in order to diagnose on clinical features. In conclusion, we preferred caudal anesthesia in this patient with fanconi anemia without thrombocytopenia, because of avoiding from N2O, reducing amount of anesthetic, existing microcephaly, hypothyroidism and elevated liver enzymes, providing postoperative analgesia, and reducing amount of analgesic used postoperatively.

  3. [Failure of primary management of developmental dislocation of the hip: 31 years experience in Normandy].

    PubMed

    Benez, C; Lechevallier, J; Abuamara, S; Durand, C; Cunin, V; Lefort, J; Borde, J

    2003-05-01

    Primary management of developmental dislocation of the hip involves a series of events (clinical screening and detection, choice and interpretation of imaging studies, indication and proper execution of treatment). Each event has an important effect on outcome and failure may result from inadequate attention to any one. We analyzed the causes of failure observed over 31 years experience in our region. We analyzed the files of children hospitalized in the Rouen Infantile Surgery Department from 1968 to 1998 for management of congenital dislocation of the hip diagnosed late (> 3 months) or for revision after inappropriate treatment. We identified 353 files. This series was retrospective from 1968 to 1985 (283 cases) and prospective from 1986 to 1998 (70 cases). Up through 1981, failed detection of developmental dislocation of the hip was identified in 10 to 27 children per year (mean 21.5). Since 1982, this rate has varied from 1 to 10 (mean 6.5). The number of children treated before the age of one year was 10.5 per year up through 1981 then 4.5 per year after 1982. The number of children treated after the age of one year was 11 per year through 1981 then 2 per year after 1982. Since 1986, treatment was undertaken for failure of primary management in 57 children after clinical diagnosis, in 3 children after radiological and ultrasonographic diagnosis, and in 11 children during the course of treatment. Standard x-ray studies systematically obtained at four months corrected the diagnosis in 24 children. The diagnosis was corrected after repeating the examination in 14 children before the age of one year. Correct diagnosis was established after the age of one year in 18 children. Although our University Department was the only referral center for pediatric surgery in our region during this period, these figures cannot be compared with the annual birth rate in the region (24,000 births/year) because the number of infants managed in other centers is unknown. Nevertheless

  4. Intraoperative dislocation of the trial bipolar cup into the pelvis during bipolar hip arthroplasty - A case report.

    PubMed

    Miyake, Takahito; Kanda, Akio; Morohashi, Itaru; Obayashi, Osamu; Mogami, Atsuhiko; Kaneko, Kazuo

    2017-06-01

    Bipolar hip arthroplasty is a good option for treating femoral neck fractures, although some contraindications have been indicated. We report a case of intraoperative dislocation of the trial bipolar cup into the pelvis during bipolar hip arthroplasty. A 74-year-old woman underwent bipolar hip arthroplasty for a femoral neck fracture (AO31-B2). She was placed in a lateral decubitus position, and a direct lateral approach was used. During intraoperative trial reduction, the trial bipolar cup became disengaged and dislocated into the anterior space of hip joint. Several attempts to retrieve it failed. The permanent femoral component was inserted, and the wound was closed. The patient was repositioned supine to allow an ilioinguinal approach, and the component was easily removed. She had an uneventful, good recovery. Several cases of intraoperative dislocation of the femoral trial head during total hip arthroplasty have been reported, this is the first report of dislocation of a bipolar trial cup. A previous report described difficulty retrieving a trial cup. We easily removed our trial cup using another approach. It is vital to plan systematically for this frustrating complication.

  5. Propensity for hip dislocation in normal gait loading versus sit-to-stand maneuvers in posterior wall acetabular fractures.

    PubMed

    Marmor, Meir; McDonald, Erik; Buckley, Jenni M; Matityahu, Amir

    2013-09-01

    Treatment of posterior wall (PW) fractures of the acetabulum is guided by the size of the broken wall fragment and by hip instability. Biomechanical testing of hip instability typically is done by simulating the single-leg-stance (SLS) phase of gait, but this does not represent daily activities, such as sit-to-stand (STS) motion. We conducted a study to examine and compare hip instability after PW fractures in SLS and STS loading. We hypothesized that wall fragment size and distance from the dome (DFD) of the acetabulum to the simulated fracture would correlate with hip instability and, in the presence of a PW fracture, the hip would be more unstable during STS loading than during SLS loading. Incremental PW osteotomies were made in 6 cadaveric acetabula. After each osteotomy, a 1200-N load was applied to the acetabulum to simulate SLS and STS loading until dislocation occurred. All hip joints in the cadaveric models were more unstable in STS loading than in SLS loading. PW fragments at time of dislocation were larger (P<.001) in SLS loading (85% ± 13%; range, 81%-100%) than in STS loading (40% ± 7%; range, 33%-52%). Mean (SD) DFD at time of dislocation was 15.0 (3.5) mm (range, 14.4-19.6 mm) in STS loading and 5.3 (4.3) mm (range, 0.1-10.0 mm) in SLS loading (P<.04). There was more hip instability in STS loading than in SLS loading. In STS loading, hips dislocated with a PW fracture size of 33% or more and a DFD of 20 mm or less.

  6. Delayed dislocation following metal-on-polyethylene arthroplasty of the hip due to 'silent' trunnion corrosion.

    PubMed

    Lash, N J; Whitehouse, M R; Greidanus, N V; Garbuz, D S; Masri, B A; Duncan, C P

    2016-02-01

    We present a case series of ten metal-on-polyethylene total hip arthroplasties (MoP THAs) with delayed dislocation associated with unrecognised adverse local tissue reaction due to corrosion at the trunnion and pseudotumour formation. The diagnosis was not suspected in nine of the ten patients (six female/four male; mean age 66 years), despite treatment in a specialist unit (mean time from index surgery to revision was 58 months, 36 to 84). It was identified at revision surgery and subsequently confirmed by histological examination of resected tissue. Pre-operative assessment and culture results ruled out infection. A variety of treatment strategies were used, including resection of the pseudotumour and efforts to avoid recurrent dislocation. The rate of complications was high and included three deep infections, two patients with recurrent dislocation, and one recurrent pseudotumour. This series (mean follow-up of 76 months following index procedure and 19 months following revision THA) demonstrates that pseudotumour is an infrequent but important contributor to delayed instability following MoP THA. It is easy to overlook in the differential diagnosis, especially if the alignment of the components is less than optimal, leading to an assumption that malalignment is the cause of the dislocation. The instability is likely to be multifactorial and the revision surgery is complex. Due to the high complication rate associated with revision in this cohort, the diagnosis should be borne in mind when counselling patients regarding the risks of revision surgery. ©2016 The British Editorial Society of Bone & Joint Surgery.

  7. Are ceramic-on-ceramic bearings in total hip arthroplasty associated with reduced revision risk for late dislocation?

    PubMed

    Pitto, Rocco P; Garland, Mikaela; Sedel, Laurent

    2015-12-01

    Dislocation is a major complication after primary total hip arthroplasty (THA), but little is known about the potential relationships between bearing materials and risk of dislocation. Dislocation within the first year after surgery is typically related to either surgical error or patient inattention to precautions, but the reasons for dislocation after the first year are often unclear, and whether ceramic bearings are associated with an increased or decreased likelihood of late dislocation is controversial. The purpose of this study was to use a national registry to assess whether the choice of bearings-metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), ceramic-on-ceramic (CoC), or metal-on-metal (MoM)-is associated with differences in the risk of late dislocation. Data from primary THAs were extracted from the New Zealand Joint Registry over a 10-year period. The mean age of patients was 69 years (SD ± 12 years), and 53% were women. The median followup in this population was 7 years (range, 1-13 years). The surgical approach used was posterior in 66% of THAs, lateral in 29%, and anterior in 5%. The primary endpoint was late revision for dislocation with "late" defined as greater than 1 year postoperatively. A total of 73,386 hips were available for analysis: 65% MoP, 17% CoP, 10% CoC, and 7% MoM. In general, patients receiving CoC and MoM bearings were younger compared with patients receiving CoP and MoP bearings. Four percent of the hips were revised (3130 THAs); 867 THAs were revised for dislocation. Four hundred seventy THAs were revised for dislocation after the first postoperative year. After adjusting for head size, age, and surgical approach, only CoP (hazard ratio [HR], 2.10; p = 0.021) demonstrated a higher proportion of revision, whereas MoP did not (HR, 1.76; 95% p = 0.075). There were no differences of revisions for dislocation in the CoC (HR, 1.60; p = 0.092) and MoM cohorts (HR, 1.54; p = 0.081). Dislocation is a common reason for revision

  8. Fate of the psoas muscle after open reduction for developmental dislocation of the hip (DDH).

    PubMed

    Bassett, G S; Engsberg, J R; McAlister, W H; Gordon, J E; Schoenecker, P L

    1999-01-01

    We evaluated the anatomic and functional consequences of psoas lengthening during operative intervention for developmental dislocation of the hip (DDH). Possible anatomic changes were assessed by magnetic resonance imaging (MRI), and functional assessment included strength determination by an isokinetic dynamometer and gait analysis. Six girls and one boy, ranging in age from 15 to 20 months, had operative reduction of a unilateral DDH. One closed and six open reductions (three anteromedial and three anterolateral approaches) were performed. Follow-up ranged from 4 years 0 months to 9 years 2 months. The cross-sectional area determined by MRI of the lengthened psoas muscles was markedly reduced for all of the six open-reduction patients (three moderate and three severe). Atrophy of the iliacus muscle also was apparent by MRI in five of the six open-reduction patients. Maximum flexion torque, as determined by the isokinetic dynamometer, was diminished on the DDH side for the three patients whose hips were reduced open through the anteromedial approach. Average hip-flexion torque over the entire range of motion was decreased for both anteromedial and anterolateral groups on the operated-on side. Lengthening of the psoas tendon during open reduction of a DDH is associated with considerable atrophy of the psoas muscle.

  9. [Medial dislocation of hip screw following internal fixation of a pertrochateric metastasis in the femur with gamma nails].

    PubMed

    Horas, U; Ernst, S

    2008-09-01

    If the standard technical guidelines are ignored so that the antirotation screw is not correctly placed during gamma nail osteosynthesis, dislocation of the hip screw is possible. In the rare cases of migration into the pelvis, the consequences may be lethal.

  10. Ceramic-on-ceramic bearing surface and risk of revision due to dislocation after primary total hip replacement.

    PubMed

    Sexton, S A; Walter, W L; Jackson, M P; De Steiger, R; Stanford, T

    2009-11-01

    Dislocation is a common reason for revision following total hip replacement. This study investigated the relationship between the bearing surface and the risk of revision due to dislocation. It was based on 110 239 primary total hip replacements with a diagnosis of osteoarthritis collected by the Australian Orthopaedic Association National Joint Replacement Registry between September 1999 and December 2007. A total of 862 (0.78%) were revised because of dislocation. Ceramic-on-ceramic bearing surfaces had a lower risk of requiring revision due to dislocation than did metal-on-polyethylene and ceramic-on-polyethylene surfaces, with a follow-up of up to seven years. However, ceramic-on-ceramic implants were more likely to have larger prosthetic heads and to have been implanted in younger patients. The size of the head of the femoral component and age are known to be independent predictors of dislocation. Therefore, the outcomes were stratified by the size of the head and age. There is a significantly higher rate of revision for dislocation in ceramic-on-ceramic bearing surfaces than in metal-on-polyethylene implants when smaller sizes (< or = 28 mm) of the head were used in younger patients (< 65 years) (hazard ratio = 1.53, p = 0.041) and also with larger (> 28 mm) and in older patients (> or = 65 years) (hazard ratio = 1.73, p = 0.016).

  11. Prosthetic Dislocation and Revision After Primary Total Hip Arthroplasty in Lumbar Fusion Patients: A Propensity Score Matched-Pair Analysis.

    PubMed

    Perfetti, Dean C; Schwarzkopf, Ran; Buckland, Aaron J; Paulino, Carl B; Vigdorchik, Jonathan M

    2017-05-01

    Lumbar-pelvic fusion reduces the variation in pelvic tilt in functional situations by reducing lumbar spine flexibility, which is thought to be important in maintaining stability of a total hip arthroplasty (THA). We compared dislocation and revision rates for patients with lumbar fusion and subsequent THA to a matched comparison cohort with hip and spine degenerative changes undergoing only THA. We identified patients in New York State who underwent primary elective lumbar fusion for degenerative disc disease pathology and subsequent THA between January 2005 and December 2012. A propensity score match was performed to compare 934 patients with prior lumbar fusion to 934 patients with only THA according to age, gender, race, Deyo comorbidity score, year of surgery, and surgeon volume. Revision and dislocation rates were assessed at 3, 6, and 12 months post-THA. At 12 months, patients with prior lumbar fusion had significantly increased rates of THA dislocation (control: 0.4%; fusion: 3.0%; P < .001) and revision (control: 0.9%; fusion: 3.9%; P < .001). At 12 months, fusion patients were 7.19 times more likely to dislocate their THA (P < .001) and 4.64 times more likely to undergo revision (P < .001). Patients undergoing lumbar fusion and subsequent THA have significantly higher risks of dislocation and revision of their hip arthroplasty than a matched cohort of patients with similar hip and spine pathology but only undergoing THA. During preoperative consultation for patients with prior lumbar fusion, orthopedic surgeons must educate the patient and family about the increased risk of dislocation and revision. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Klippel-Trenaunay syndrome in combination with congenital dislocation of the hip.

    PubMed

    Hu, Peng; Zhang, Guo You; Wang, Yang; Cheng, Yan; Wang, Li Li

    2013-04-01

    Klippel-Trenaunay syndrome (KTS) is a rare and sporadic disorder characterized by the triad of capillary malformations, venous varicosities, and limb hypertrophy. The clinical manifestations of KTS are heterogeneous. In this report, we present a unique case of KTS in combination with congenital dislocation of the hip (CDH) in a 4-day-old female neonate. The patient had a widespread port-wine stain surrounded by regions of unaffected skin in a mosaic pattern, cutaneous hemangioma on the upper lip, left-sided hemihypertrophy involving the entire body, and also evidence of left CDH (based on the results of a physical examination and radiographic interpretation). We present this case for the rarity of presentation, discuss the relationship between KTS and CDH, and the treatment options available with a brief review of the literature. Copyright © 2012. Published by Elsevier B.V.

  13. Hip Dislocation and Dystocia in Early Medieval Times: Possible Evidence of Labor Maneuver.

    PubMed

    Malgosa, Assumpció; Carrascal, Susana; Piga, Giampaolo; Isidro, Albert

    2016-12-01

    In ancient times, maternal mortality would occur frequently, particularly during labor. Evidence of dystocia resulting in the death of a pregnant woman is very infrequent in paleopathologic literature, with only a few cases being demonstrated. In the early medieval site of Casserres, the skeleton of a young woman with a fetus in the pelvic region was found. Some abnormal findings of the maternal skeleton were evaluated, including a sacral anomaly, femoral head wound, the rare position of the lower left limb with the femoral head dislodged anteriorly and cephalad from the socket, and a fibular fracture. Examining the anomalies all together, a case of anterior hip dislocation related to a McRoberts-like maneuver performed during labor is a plausible explanation of the findings.

  14. High-grade SCFE: the role of surgical hip dislocation and reduction.

    PubMed

    Sucato, Daniel J; De La Rocha, Adriana

    2014-01-01

    The patient with an unstable slipped capital femoral epiphysis poses a challenging problem to the treating physician to improve the position of the displaced epiphysis to avoid femoroacetabular impingement without developing avascular necrosis (AVN)-a potentially devastating complication. Although the standard operative procedure of in situ pinning following an incidental reduction while positioning the patient on the table, has been the mainstay of treatment in North America, other viable options are available including a surgical dislocation approach to the hip followed by a modified Dunn osteotomy with control of the retinacular vessels, reduction of the epiphysis, and internal fixation with pins or screws. Although technically demanding, this approach offers an opportunity to reduce the epiphysis to avoid femoroacetabular impingement, and limit the possibility for the development of AVN. The early results for this procedure are promising with all studies demonstrating excellent reduction of the epiphysis and an overall lower incidence of AVN when compared with in situ pinning.

  15. Total hip arthroplasty without femoral osteotomy in patients who had high and low dislocation due to developmental dysplasia of the hip.

    PubMed

    Kiyak, Gorkem; Bezer, Murat; Ketenci, Ismail E; Topkar, Osman M

    2016-01-01

    Various surgical techniques and outcome results have been reported after primary total hip arthroplasty for the treatment of patients dysplastic hips. Low failure and complication rates have been reported when the acetabular component has been placed in the true acetabulum. The current study reports the results of primary total hip arthroplasty in patients with high and low dislocation for whom the acetabular component was placed in the true acetabulum without femoral or trochanteric osteotomy. 26 primary total hip replacements were performed on 22 patients. The mean duration of follow-up was 8.9 years.There were 4 men and 18 women. 17 hips were classified as type B (low dislocation) and 9 as type C (high dislocation), according to the classification system of Hartofilakidis et al. Acetabular components were placed in the true acetabulum without osteotomy for all patients. At the time of final follow-up (mean 8.9 years) the average Harris Hip Score was 85 points. Femoral head autograft was used in 9 hips to supplement acetabular coverage. In 8 patient linear calcar fracture. 7 fixed with Dall-Mile cable and 1 fixed with a side plate. On radiologic evaluation, 2 incidents of asymptomatic osteolysis, 1 of acetabular loosening, 1 graft resorption, and 1 impingement (correlated with physical examination) were identified. 2 patients had neuropraxia and were treated medically. There were no early or late infections. Only 1 patient with acetabular loosening required revision surgery. Although it is surgically difficult to place the acetabular component in the true acetabulum without femoral or trochanteric osteotomy, at the final follow-up we report favourable results. Long-term follow-up is needed to verify our results.

  16. A Novel Approach for Dynamic Testing of Total Hip Dislocation under Physiological Conditions

    PubMed Central

    Herrmann, Sven; Kluess, Daniel; Kaehler, Michael; Grawe, Robert; Rachholz, Roman; Souffrant, Robert; Zierath, János; Bader, Rainer; Woernle, Christoph

    2015-01-01

    Constant high rates of dislocation-related complications of total hip replacements (THRs) show that contributing factors like implant position and design, soft tissue condition and dynamics of physiological motions have not yet been fully understood. As in vivo measurements of excessive motions are not possible due to ethical objections, a comprehensive approach is proposed which is capable of testing THR stability under dynamic, reproducible and physiological conditions. The approach is based on a hardware-in-the-loop (HiL) simulation where a robotic physical setup interacts with a computational musculoskeletal model based on inverse dynamics. A major objective of this work was the validation of the HiL test system against in vivo data derived from patients with instrumented THRs. Moreover, the impact of certain test conditions, such as joint lubrication, implant position, load level in terms of body mass and removal of muscle structures, was evaluated within several HiL simulations. The outcomes for a normal sitting down and standing up maneuver revealed good agreement in trend and magnitude compared with in vivo measured hip joint forces. For a deep maneuver with femoral adduction, lubrication was shown to cause less friction torques than under dry conditions. Similarly, it could be demonstrated that less cup anteversion and inclination lead to earlier impingement in flexion motion including pelvic tilt for selected combinations of cup and stem positions. Reducing body mass did not influence impingement-free range of motion and dislocation behavior; however, higher resisting torques were observed under higher loads. Muscle removal emulating a posterior surgical approach indicated alterations in THR loading and the instability process in contrast to a reference case with intact musculature. Based on the presented data, it can be concluded that the HiL test system is able to reproduce comparable joint dynamics as present in THR patients. PMID:26717236

  17. Posterior dislocation of the elbow as an unusual presentation after a total hip replacement: a case report

    PubMed Central

    Periasamy, Kumar; Meek, Dominic; Crossman, Paul

    2008-01-01

    Introduction Posterior dislocation of the elbow is usually associated with trauma to the joint with a reported incidence of 3%to 6%. Chronic instability is usually symptomatic following the initial injury. Case presentation We report a case of posterior dislocation of the elbow occurring in a patient while using her arm to lift herself using a monkey pole on the second day following a total hip replacement. The dislocation was reduced under sedation in the ward. There were no signs or symptoms suggesting any joint hypermobility syndrome in the patient. Follow up 4 months following the injury revealed a complete recovery in the range of motion and a pain free elbow. There were no signs and symptoms of any instability. Conclusion This is the first time such a case is reported in the literature. It certainly demonstrates that even in the absence of instability a patient can be predisposed to low energy dislocation of the elbow. PMID:18254950

  18. Total hip arthroplasty using the Wroblewski golf ball cup inserted through the posterior approach. A high rate of dislocation.

    PubMed

    Porter, P; Stone, M H

    2004-07-01

    The Wroblewski golf ball acetabular cup was introduced by surgeons using the trochanteric osteotomy approach for revision total hip replacement (THR) in order to reduce the rate of dislocation. We have routinely used the Ogee long posterior wall (Ogee LPW) and the Wroblewski angle bore cups in THR. Although the new Wroblewski golf ball cup performed well there was a significant early rate of dislocation of 20%. Our rate of dislocation over a period of ten years using the Ogee LPW and Wroblewski angle bore cups had been 0.52%. We present our findings and an investigation as to why the new cup has such a high rate of dislocation when used with the posterior approach. We show that a relatively small change in the design of the acetabular component resulted in significant adverse clinical results.

  19. Effect of femoral head size and surgical approach on risk of revision for dislocation after total hip arthroplasty.

    PubMed

    Zijlstra, Wierd P; De Hartog, Bas; Van Steenbergen, Liza N; Scheurs, B Willem; Nelissen, Rob G H H

    2017-08-01

    Background and purpose - Recurrent dislocation is the commonest cause of early revision of a total hip arthropasty (THA). We examined the effect of femoral head size and surgical approach on revision rate for dislocation, and for other reasons, after total hip arthroplasty (THA). Patients and methods - We analyzed data on 166,231 primary THAs and 3,754 subsequent revision THAs performed between 2007 and 2015, registered in the Dutch Arthroplasty Register (LROI). Revision rate for dislocation, and for all other causes, were calculated by competing-risk analysis at 6-year follow-up. Multivariable Cox proportional hazard regression ratios (HRs) were used for comparisons. Results - Posterolateral approach was associated with higher dislocation revision risk (HR =1) than straight lateral, anterolateral, and anterior approaches (HR =0.5-0.6). However, the risk of revision for all other reasons (especially stem loosening) was higher with anterior and anterolateral approaches (HR =1.2) and lowest with posterolateral approach (HR =1). For all approaches, 32-mm heads reduced the risk of revision for dislocation compared to 22- to 28-mm heads (HR =1 and 1.6, respectively), while the risk of revision for other causes remained unchanged. 36-mm heads increasingly reduced the risk of revision for dislocation but only with the posterolateral approach (HR =0.6), while the risk of revision for other reasons was unchanged. With the anterior approach, 36-mm heads increased the risk of revision for other reasons (HR =1.5). Interpretation - Compared to the posterolateral approach, direct anterior and anterolateral approaches reduce the risk of revision for dislocation, but at the cost of more stem revisions and other revisions. For all approaches, there is benefit in using 32-mm heads instead of 22- to 28-mm heads. For the posterolateral approach, 36-mm heads can safely further reduce the risk of revision for dislocation.

  20. Outcome of unstable isolated fractures of the posterior acetabular wall associated with hip dislocation.

    PubMed

    de Palma, L; Santucci, A; Verdenelli, A; Bugatti, M G; Meco, L; Marinelli, M

    2014-04-01

    Traumatic hip dislocation with fracture of the posterior acetabular wall is associated with high rates of residual invalidity. The records of patients who underwent surgical treatment of traumatic dislocation of the hip associated with an isolated fracture of the posterior acetabular wall from 1999 to 2009 were reviewed. There were 30 men and 12 women, who at the time of the trauma had a mean age of 42 years (range 21-65). Mean follow-up duration was 5 years (range 2-10). Pre-operative fracture evaluation was based on the classification of Judet et al. which divided this fractures into three types: type 1 is characterized by a single fracture line separating a single bone fragment from the remaining part of the posterior wall; type 2 fracture involves several fragments of the posterior wall and in type 3, a type 1 or type 2 fracture is associated with a sunk cancellous area in the acetabular wall medial to the fracture line but not affected by it, due to the shear impact of the femoral head at the time of dislocation. Clinical evaluation of the outcome was according to the criteria of Merle D'Aubigné and Postel as modified by Matta. Outcomes were divided into excellent/good and fair/poor. Since treatment was standard, data were further analyzed to assess the relative importance of age, sex, follow-up duration, sciatic nerve lesion on admission and mechanism of injury, using the Chi-square test. Full clinical recovery without sequelae or radiographic abnormalities was achieved by 10 patients, 8 with type 1 fracture and 2 with type 2 fracture. A good outcome was seen in 13 patients, 3 with type 1 fracture, 9 with type 2 fracture and 1 with type 3 fracture. Eight patients, 3 with type 2 fracture and 5 with type 3 fracture, had a fair outcome. Only follow-up ≥6 years influenced outcome significantly (p > 0.005). Our conclusions in light of our experience are that in type 1 lesions, anatomical reduction and stabilization achieve excellent outcomes, both clinical

  1. Relationship Between Developmental Dislocation of the Hip in Infant and Acetabular Dysplasia at Skeletal Maturity

    PubMed Central

    Okano, Kunihiko; Yamaguchi, Kazumasa; Ninomiya, Yoshikazu; Matsubayashi, Shohei; Aoyagi, Kiyoshi; Osaki, Makoto; Enomoto, Hiroshi; Takahashi, Katsuro

    2015-01-01

    Abstract Previous reports demonstrated 8–60% patients treated for developmental dislocation of hip (DDH) in infancy have residual acetabular dysplasia (AD) at skeletal maturity. AD patients reportedly exhibit abnormal morphology of the pelvis, high rates of comorbid spinal congenital anomalies and high bone mineral density. These physical findings suggest that AD patients have genetic background. We examined the percentage of AD patients with hip pain at skeletal maturity having a history of DDH in infancy and the correlation between the severity of AD at skeletal maturity and history of DDH treatment to investigate the relationship between AD and DDH. A total of 245 patients were radiographically examined for any history of DDH treatment in infancy. The study included 226 women and 19 men with a mean age at examination of 40.7 years (range 17–59 years). Eighty-eight patients (36%) had a history of DDH treatment (DDH group) and the remaining 157 patients (64%) had no history of DDH treatment (non-DDH group). The average age was lower and acetabular angle was larger in the DDH group. There was a significant increasing trend of the percentage of DDH patients associated with the severity of AD classified with CE, acetabular angle, and acetabular roof angle. Our data suggest that there are several AD patients without a history of DDH in Japan, and AD in patients without a history of DDH has different characteristics from AD in patients with a history of DDH. PMID:25569642

  2. Relationship between developmental dislocation of the hip in infant and acetabular dysplasia at skeletal maturity.

    PubMed

    Okano, Kunihiko; Yamaguchi, Kazumasa; Ninomiya, Yoshikazu; Matsubayashi, Shohei; Aoyagi, Kiyoshi; Osaki, Makoto; Enomoto, Hiroshi; Takahashi, Katsuro

    2015-01-01

    Previous reports demonstrated 8-60% patients treated for developmental dislocation of hip (DDH) in infancy have residual acetabular dysplasia (AD) at skeletal maturity. AD patients reportedly exhibit abnormal morphology of the pelvis, high rates of comorbid spinal congenital anomalies and high bone mineral density. These physical findings suggest that AD patients have genetic background. We examined the percentage of AD patients with hip pain at skeletal maturity having a history of DDH in infancy and the correlation between the severity of AD at skeletal maturity and history of DDH treatment to investigate the relationship between AD and DDH.A total of 245 patients were radiographically examined for any history of DDH treatment in infancy. The study included 226 women and 19 men with a mean age at examination of 40.7 years (range 17-59 years).Eighty-eight patients (36%) had a history of DDH treatment (DDH group) and the remaining 157 patients (64%) had no history of DDH treatment (non-DDH group). The average age was lower and acetabular angle was larger in the DDH group. There was a significant increasing trend of the percentage of DDH patients associated with the severity of AD classified with CE, acetabular angle, and acetabular roof angle.Our data suggest that there are several AD patients without a history of DDH in Japan, and AD in patients without a history of DDH has different characteristics from AD in patients with a history of DDH.

  3. Efficacy of revision surgery for the dislocating total hip arthroplasty: report from a large community registry.

    PubMed

    Salassa, Tiare; Hoeffel, Daniel; Mehle, Susan; Tatman, Penny; Gioe, Terence J

    2014-03-01

    Historically, achieving stability for the unstable total hip arthroplasty (THA) with revision surgery has been achieved inconsistently. Most of what we know about this topic comes from reports of high-volume surgeons' results; the degree to which these results are achieved in the community is largely unknown, but insofar as most joint replacements are done by community surgeons, the issue is important. We used a community joint registry to determine: (1) the frequency of repeat revision after surgery to treat the unstable THA; (2) what surgical approaches to this problem are in common use in the community now; (3) are there differences in repeat revision frequency that vary by approach used; and (4) has the frequency of repeat revision decreased over time as surgical technique and implant options have evolved? We reviewed 6801 primary THAs performed in our community joint registry over the last 20 years. One hundred eighteen patients (1.7%) with a mean age of 67 years were revised within the registry for instability/dislocation. Failure was defined as a return to the operating room for rerevision surgery for instability. Minimum followup was 2 years (average, 9.4 years; range, 2-20 years) with six patients having incomplete followup. The frequency of rerevisions was calculated and compared using Pearson's chi-square test. Cumulative rerevision rates were calculated using the Kaplan-Meier method and types of revision procedures were compared using the log-rank test. The initial revision procedure was successful in 108 patients (92%); 10 patients underwent repeat surgery for recurrent dislocation after their initial revision surgery. The most frequently performed procedure was revision of the head and liner only (35 of 118 [30%]); constrained devices were used in 19% (22 of 118) of the procedures. There was no difference in the cumulative rerevision rates for instability or dislocation by type of revision procedure performed. Six of 22 constrained liners were

  4. Simultaneous shoulder and hip dislocation in a 12-year-old girl with Hutchinson-Gilford progeria syndrome.

    PubMed

    Espandar, Ramin; Eraghi, Amir Sobhani; Mardookhpour, Shirin

    2012-01-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature ageing disorder that is characterized by accelerated degenerative changes of the cutaneous, musculoskeletal and cardiovascular systems. Mean age at diagnosis is 2.9 years and generally leading to death at approximately 13 years of age due to myocardial infarction or stroke. Orthopedic manifestations of HGPS are multiple and shoulder dislocation is a rare skeletal trauma in progeria syndrome. Our patient had simultaneous shoulder and hip dislocation associated with a low energy trauma. This subject has not been reported. Treatment accomplished as close reduction under general anesthesia and immobilization.

  5. The Pavlik harness in the treatment of developmentally dislocated hips: results of Japanese multicenter studies in 1994 and 2008.

    PubMed

    Wada, Ikuo; Sakuma, Eisuke; Otsuka, Takanobu; Wakabayashi, Kenjiro; Ito, Kinya; Horiuchi, Osamu; Asagai, Yoshimi; Kamegaya, Makoto; Goto, Eiji; Satsuma, Shinichi; Kobayashi, Daisuke; Saito, Susumu; Taketa, Mayuki; Takikawa, Kazuharu; Nakashima, Yasuharu; Hattori, Tadashi; Mitani, Shigeru; Wada, Akifusa

    2013-09-01

    It has already been more than 50 years since the Pavlik harness was introduced in Japan, and today the Pavlik harness is widely recognized as the standard initial treatment modality for developmental dysplasia of the hip. We performed a multicenter nationwide questionnaire study concerning the results of Pavlik harness treatment twice in 1994 and 2008. In 1994 and in 2008, we sent questionnaires to 12 institutes in Japan specializing mainly in pediatric orthopedics. We compare the results of these two studies and discuss differences in reduction rates, incidence of avascular necrosis in the femoral epiphysis and the percentage of joints with acceptable morphology (Severin grade I + II/total) at skeletal maturity. We statistically assessed these results to see whether there were changes in the treatment outcomes over this 14-year period. Reduction of the dislocated hips was obtained by the Pavlik harness in 80.2% (1990/2481 hips; 1994) and 81.9% (1248/1523 hips; 2008). The incidences of avascular necrosis of the proximal femoral epiphysis in the dysplastic hips were 14.3% (119/835 hips; 1994) and 11.5% (76/663 hips; 2008). The type of avascular necrosis in hips from the 2008 study was determined according to the classification of Kalamchi and MacEwen: 24/69 hips (34.8%) were classified as group I; 20/69 hips (29.0%) as group II; 11/69 hips (15.9%) as group Ill; 14/69 hips (20.3%) as group IV. The percentages of hips with acceptable outcomes at skeletal maturity discerned from Severin X-ray changes (grade I + II/total) were 72.3% (604/835 hips; 1994) and 77.7% (488/628 hips; 2008). Reduction rates and the incidence of avascular necrosis in 2008 were statistically similar to the results in 1994. The rate of acceptable outcome (Severin grade I + II/total) in 2008 was statistically higher than that of 1994.

  6. Evaluation of Brace Treatment for Infant Hip Dislocation in a Prospective Cohort: Defining the Success Rate and Variables Associated with Failure.

    PubMed

    Upasani, Vidyadhar V; Bomar, James D; Matheney, Travis H; Sankar, Wudbhav N; Mulpuri, Kishore; Price, Charles T; Moseley, Colin F; Kelley, Simon P; Narayanan, Unni; Clarke, Nicholas M P; Wedge, John H; Castañeda, Pablo; Kasser, James R; Foster, Bruce K; Herrera-Soto, Jose A; Cundy, Peter J; Williams, Nicole; Mubarak, Scott J

    2016-07-20

    The use of a brace has been shown to be an effective treatment for hip dislocation in infants; however, previous studies of such treatment have been single-center or retrospective. The purpose of the current study was to evaluate the success rate for brace use in the treatment of infant hip dislocation in an international, multicenter, prospective cohort, and to identify the variables associated with brace failure. All dislocations were verified with use of ultrasound or radiography prior to the initiation of treatment, and patients were followed prospectively for a minimum of 18 months. Successful treatment was defined as the use of a brace that resulted in a clinically and radiographically reduced hip, without surgical intervention. The Mann-Whitney test, chi-square analysis, and Fisher exact test were used to identify risk factors for brace failure. A multivariate logistic regression model was used to determine the probability of brace failure according to the risk factors identified. Brace treatment was successful in 162 (79%) of the 204 dislocated hips in this series. Six variables were found to be significant risk factors for failure: developing femoral nerve palsy during brace treatment (p = 0.001), treatment with a static brace (p < 0.001), an initially irreducible hip (p < 0.001), treatment initiated after the age of 7 weeks (p = 0.005), a right hip dislocation (p = 0.006), and a Graf-IV hip (p = 0.02). Hips with no risk factors had a 3% probability of failure, whereas hips with 4 or 5 risk factors had a 100% probability of failure. These data provide valuable information for patient families and their providers regarding the important variables that influence successful brace treatment for dislocated hips in infants. Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

  7. Dysplasia of the contralateral hip in patients with unilateral late-detected congenital dislocation of the hip: 50 years' follow-up of 48 patients.

    PubMed

    Terjesen, T

    2014-09-01

    The aim of this study was to investigate the incidence of dysplasia in the 'normal' contralateral hip in patients with unilateral developmental dislocation of the hip (DDH) and to evaluate the long-term prognosis of such hips. A total of 48 patients (40 girls and eight boys) were treated for late-detected unilateral DDH between 1958 and 1962. After preliminary skin traction, closed reduction was achieved at a mean age of 17.8 months (4 to 65) in all except one patient who needed open reduction. In 25 patients early derotation femoral osteotomy of the contralateral hip had been undertaken within three years of reduction, and later surgery in ten patients. Radiographs taken during childhood and adulthood were reviewed. The mean age of the patients was 50.9 years (43 to 55) at the time of the latest radiological review. In all, eight patients (17%) developed dysplasia of the contralateral hip, defined as a centre-edge (CE) angle < 20° during childhood or at skeletal maturity. Six of these patients underwent surgery to improve cover of the femoral head; the dysplasia improved in two after varus femoral osteotomy and in two after an acetabular shelf operation. During long-term follow-up the dysplasia deteriorated to subluxation in two patients (CE angles 4° and 5°, respectively) who both developed osteoarthritis (OA), and one of these underwent total hip replacement at the age of 49 years. In conclusion, the long-term prognosis for the contralateral hip was relatively good, as OA occurred in only two hips (4%) at a mean follow-up of 50 years. Regular review of the 'normal' side is indicated, and corrective surgery should be undertaken in those who develop subluxation. ©2014 The British Editorial Society of Bone & Joint Surgery.

  8. Proximal femoral resection arthroplasty for patients with cerebral palsy and dislocated hips: 20 patients followed for 1-6 years.

    PubMed

    Knaus, Andreas; Terjesen, Terje

    2009-02-01

    Chronic hip dislocation in non-ambulatory individuals with cerebral palsy (CP) can lead to severe problems, of which pain is often the most severe. We studied the outcome of proximal femoral resection, especially regarding pain, sitting balance, perineal care, and patient satisfaction. During the period 1998-2005, we operated 20 non-ambulatory patients with spastic quadriplegic CP (8 females and 12 males). 13 patients had unilateral dislocation and 7 had bilateral. The mean age at operation was 15 (3-27) years. The indications for operation were chronic hip dislocation plus severe problems with pain (17 patients), perineal care (16), and sitting (10). Patients were followed from 1 to 6 years. 14 patients were satisfied with the surgery, 3 were dissatisfied, 2 were uncertain, and 1 patient had died 5 days postoperatively. Of the 15 patients who had suffered from considerable pain before surgery, 8 had complete relief from pain and 7 patients experienced improvement. Of the 2 patients who had had mild pain, 1 was unchanged and 1 patient deteriorated. All patients who had not been able to sit were able to sit after the surgery. Only 1 patient had difficulties with perineal hygiene at follow-up. Postoperative complications included deep vein thrombosis (1 patient) and edema, loss of appetite, and the need for gastrostomy (1 patient). 7 patients had prolonged pain for up to 6 months after surgery. 1 of these was reoperated because of persistent pain due to a bony-spike heterotopic ossification. Most patients with chronic hip dislocation and severe pain or other major problems appear to benefit from proximal femoral resection. Pain, sitting ability, and perineal care improved and most patients and caregivers were satisfied.

  9. Double mobility cup total hip arthroplasty in patients at high risk for dislocation: a single-center analysis.

    PubMed

    Kaiser, Dominik; Kamath, Atul F; Zingg, Patrick; Dora, Claudio

    2015-12-01

    Double mobility cup systems (DMCS) have gained increasing acceptance, especially in patients at high risk for dislocation. The aim of this investigation was to analyze the frequency and indications of the DMCS use in our praxis and to evaluate dislocation and cup revision rates after a minimum follow-up of 2 years. All patients implanted with a DMCS from May 2008 to August 2011 were identified from our institutional database of primary and revision THA procedures. Patient demographics, including ASA score, were recorded, along with details of the surgical procedures, indications for DMCS use, and post-operative clinical course and any complications. Radiographs were analyzed for implant positioning and radiological signs of loosening. 1046 primary THA were implanted, of these 39 (4 %) primary DMCS. Indications were severe neuromuscular disease (SND) (14), hip abductor degeneration (HAD) (9), cognitive dysfunction (CD) (8) and others. 345 revision THA were performed, of these 50 (14 %) revision DMCS. Indications were recurrent dislocations (27), multiple prior hip surgeries (13), HAD (5), CD (3) and others. Overall dislocation rate was 2/89 (2 %); both in revision THA. Overall cup revision rate was 5/89 (6 %): 3 septic, 1 periprosthetic acetabular fracture, 1 "intraprosthetic dissociation". 67 patients were available for the standardized questionnaire at a median follow-up of 43 months (range 25-78). 19 patients were not available for two-year follow-up: 17 died and two were lost to follow-up. This study supports the use of DMCS constructs in primary and revision hip arthroplasty for specific high-risk patients. We continue to indicate DMCS in this patient group. We do caution against extending indications for DMCS to lower risk patient groups due to unknown issues surrounding wear and component longevity.

  10. What Risk Factors and Characteristics Are Associated With Late-presenting Dislocations of the Hip in Infants?

    PubMed

    Mulpuri, Kishore; Schaeffer, Emily K; Andrade, Janice; Sankar, Wudbhav N; Williams, Nicole; Matheney, Travis H; Mubarak, Scott J; Cundy, Peter J; Price, Charles T

    2016-05-01

    Most infants with developmental dysplasia of the hip (DDH) are diagnosed within the first 3 months of life. However, late-presenting DDH (defined as a diagnosis after 3 months of age) does occur and often results in more complex treatment and increased long-term complications. Specific risk factors involved in late-presenting DDH are poorly understood, and clearly defining an associated set of factors will aid in screening, detection, and prevention of this condition. Using a multicenter database of patients with DDH, we sought to determine whether there were differences in (1) risk factors or (2) the nature of the dislocation (laterality and joint laxity) when comparing patients with early versus late presentation. A retrospective review of prospectively collected data from a multicenter database of patients with dislocated hips was conducted from 2010 to 2014. Baseline demographics for fetal presentation (cephalic/breech), birth presentation (vaginal/cesarean), birth weight, maternal age, maternal parity, gestational age, family history, and swaddling history of patients were compared among nine different sites for patients who were enrolled at age younger than 3 months and those enrolled between 3 and 18 months of age. A total of 392 patients were enrolled at baseline between 0 and 18 months of age with at least one dislocated hip. Of that group, 259 patients were younger than 3 months of age and 133 were 3 to 18 months of age. The proportion of patients with DDH who were enrolled and followed at the nine participating centers was 98%. A univariate/multivariate analysis was performed comparing key baseline demographics between early- and late-presenting patients. After controlling for relevant confounding variables, two variables were identified as risk factors for late-presenting DDH as compared with early-presenting: cephalic presentation at birth and swaddling history. Late-presenting patients were more likely to have had a cephalic presentation than early

  11. Retroversion of the acetabular dome after Salter and triple pelvic osteotomy for congenital dislocation of the hip.

    PubMed

    Dora, Claudio; Mascard, Eric; Mladenov, Kiril; Seringe, Raphael

    2002-01-01

    Retroversion of the acetabular dome has been associated with hip pain and osteoarthritis in several studies. Nevertheless, this acetabular alignment received little attention when studying the radiological outcome of pelvic osteotomies in childhood. We therefore reviewed the charts and X-rays of 73 patients with congenital dislocations, who underwent 97 pelvic osteotomies in childhood. We focussed our attention on anterior overcoverage or retroversion of the acetabular dome, respectively. Eighty-six Salter and 11 LeCoeur osteotomies were performed on patients with a mean age of 4.8 years. The mean age at last X-ray documentation was 16.5 years. The version of the acetabular dome was estimated qualitatively from the relationship of the anterior and posterior border to each other and measured semiquantitatively using templates developed by Hefti. According to Lequesne's criteria 94% of the hips were normal or borderline at maturity. A retroverted acetabular dome was present in 27% and averaged -15 degrees. It was more frequent (60% versus 24%) and more pronounced (-16 degrees versus +5 degrees) after Le Coeur's than after Salter's osteotomy and in the residually dysplastic hips (83% versus 22%; -15 degrees versus +3 degrees). It is suggested that anterior overcoverage of the femoral head results from ignorance, when choosing the type and performing the pelvic osteotomy, of where coverage needs to be improved in an individual hip. We question the long-term outcome of these hips because such rotational misalignment has been suggested to be associated with early hip pain and osteoarthritis. In order to avoid such misalignment, preoperative evaluation of where coverage needs to be improved in an individual hip and efforts for better intraoperative control of acetabular reorientation should be made.

  12. Total hip arthroplasty using direct anterior approach and dual mobility cup: safe and efficient strategy against post-operative dislocation.

    PubMed

    Batailler, Cécile; Fary, Camdon; Batailler, Pierre; Servien, Elvire; Neyret, Philippe; Lustig, Sébastien

    2017-03-01

    We hypothesize that a dual mobility cup can be safely used via the direct anterior approach, without increasing the risk of complications or incorrect positioning. This retrospective study compared 201 primary total hip arthroplasties using a dual mobility cup performed via direct anterior approach without a traction table, to 101 arthroplasties performed via posterolateral approach. Implant positioning, function scores, and early complications were recorded. Implant positioning was appropriate in both groups, with a higher cup anteversion in direct anterior approach. The complications rates were similar in both groups, with no dislocation or infection. The direct anterior approach without traction table associated with a dual mobility cup does not increase the risk of complications or non-optimal positioning of implants. This strategy is interesting for patients with high risk of post-operative dislocation.

  13. Ultrasound examination for the early determination of dysplasia and congenital dislocation of neonatal hips.

    PubMed

    Schuler, P; Feltes, E; Kienapfel, H; Griss, P

    1990-09-01

    Hip sonography enables an accurate and clinically relevant evaluation of hip maturation during the first days of human life. Experience has shown that an integration of hip sonography into neonatal screening programs is useful and necessary because clinical and even roentgenographic examination does not always establish a confirmed diagnosis of dysplasia.

  14. Dislocation of a primary total hip arthroplasty is more common in patients with a lumbar spinal fusion.

    PubMed

    Buckland, A J; Puvanesarajah, V; Vigdorchik, J; Schwarzkopf, R; Jain, A; Klineberg, E O; Hart, R A; Callaghan, J J; Hassanzadeh, H

    2017-05-01

    Lumbar fusion is known to reduce the variation in pelvic tilt between standing and sitting. A flexible lumbo-pelvic unit increases the stability of total hip arthroplasty (THA) when seated by increasing anterior clearance and acetabular anteversion, thereby preventing impingement of the prosthesis. Lumbar fusion may eliminate this protective pelvic movement. The effect of lumbar fusion on the stability of total hip arthroplasty has not previously been investigated. The Medicare database was searched for patients who had undergone THA and spinal fusion between 2005 and 2012. PearlDiver software was used to query the database by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedural code for primary THA and lumbar spinal fusion. Patients who had undergone both lumbar fusion and THA were then divided into three groups: 1 to 2 levels, 3 to 7 levels and 8+ levels of fusion. The rate of dislocation in each group was established using ICD-9-CM codes. Patients who underwent THA without spinal fusion were used as a control group. Statistical significant difference between groups was tested using the chi-squared test, and significance set at p < 0.05. At one-year follow-up, 14 747 patients were found to have had a THA after lumbar spinal fusion (12 079 1 to 2 levels, 2594 3 to 7 levels, 74 8+ levels). The control group consisted of 839 004 patients. The dislocation rate in the control group was 1.55%. A higher rate of dislocation was found in patients with a spinal fusion of 1 to 2 levels (2.96%, p < 0.0001) and 3 to 7 levels (4.12%, p < 0.0001). Patients with 3 to 7 levels of fusion had a higher rate of dislocation than patients with 1 to 2 levels of fusion (odds ratio (OR) = 1.60, p < 0.0001). When groups were matched for age and gender to the unfused cohort, patients with 1 to 2 levels of fusion had an OR of 1.93 (95% confidence interval (CI) 1.42 to 2.32, p < 0.001), and those with 3 to 7 levels of fusion an OR of 2.77 (CI

  15. Comparison of dual-mobility cup and unipolar cup for prevention of dislocation after revision total hip arthroplasty

    PubMed Central

    Gonzalez, Amanda Inez; Bartolone, Placido; Lubbeke, Anne; Dupuis Lozeron, Elise; Peter, Robin; Hoffmeyer, Pierre; Christofilopoulos, Panayiotis

    2017-01-01

    Background and purpose — Revision total hip arthroplasty (THA) is associated with higher dislocation rates than primary THA. We compared the risk of dislocation within 6 months and all-cause re-revision during the whole study period using either the dual-mobility cup or the unipolar cup. Methods — We used a prospective hospital registry-based cohort including all total and cup-only revision THAs performed between 2003 and 2013. The cups used were either dual-mobility or unipolar; the choice was made according to the preference of the surgeon. 316 revision THAs were included. The mean age of the cohort was 69 (25–98) years and 160 THAs (51%) were performed in women. The dual-mobility group (group 1) included 150 THAs (48%) and the mean length of follow-up was 31 (0–128) months. The unipolar group (group 2) included 166 THAs (53%) and the mean length of follow-up was 52 (0–136) months. Results — The incidence of dislocation within 6 months was significantly lower with the dual-mobility cup than with the unipolar cup (2.7% vs. 7.8%). The unadjusted risk ratio (RR) was 0.34 (95% CI: 0.11–1.02) and the adjusted RR was 0.28 (95% CI: 0.09–0.87). The number of patients needed to treat with a dual-mobility cup in order to prevent 1 case of dislocation was 19. The unadjusted incidence rate ratio for all-cause re-revision in the dual-mobility group compared to the unipolar group was 0.6 (95% CI: 0.3–1.4). Interpretation — Use of a dual-mobility rather than a unipolar cup in revision THA reduced the risk of dislocation within 6 months. PMID:27841712

  16. Growth disturbance of the proximal part of the femur after treatment for congenital dislocation of the hip.

    PubMed

    Keret, D; MacEwen, G D

    1991-03-01

    The radiographs of ninety patients in whom treatment of unilateral congenital dislocation of the hip was complicated by disturbance of growth of the proximal part of the femur were studied retrospectively. All patients were followed until closure of the affected proximal femoral physis. We divided the patients into three groups, according to the degree of vascular insufficiency: patients who had mild vascular insufficiency of the hip, which had little effect on growth; those who had moderate vascular insufficiency, which produces partial arrest of growth; and those who had severe vascular insufficiency, which causes complete arrest of growth. Good correlation was found between the initial degree of vascular insufficiency and the radiographic results at the most recent follow-up. The radiographic signs that were used to predict the extent of physeal involvement were a crescent-shaped epiphysis, medial bowing of the femoral neck (a shorter and more concave curve between the lesser trochanter and the proximal femoral metaphysis [the lateral portion of the Shenton line]), lateral tilting of the capital epiphysis, and premature physeal closure. Signs that were diagnostic of existing physeal involvement were elevation of the greater trochanter and shortening of the affected extremity. The presence and severity of these signs correlated well with the degree of vascular insufficiency. Medial bowing was the most reliable prognostic factor for the determination of the fate of the hip joint at maturity.

  17. Hip Dislocation Increases Roughness of Oxidized Zirconium Femoral Heads in Total Hip Arthroplasty: An Analysis of 59 Retrievals

    PubMed Central

    Moussa, Mohamed E.; Esposito, Christina I.; Elpers, Marcella E.; Wright, Timothy M.; Padgett, Douglas E.

    2014-01-01

    The aims of this study were to assess damage on the surface of retrieved oxidized zirconium metal (OxZr) femoral heads, to measure surface roughness of scratches, and to evaluate the extent of surface effacement using scanning electron microscopy (SEM). Ceramic zirconia-toughened alumina (ZTA) heads were analyzed for comparison. OxZr femoral heads explanted for recurrent dislocation had the most severe damage (p<0.001). The median surface roughness of damaged OxZr femoral heads was 1.49μm, compared to 0.084μm for damaged ZTA heads and 0.052μm for undamaged OxZr (p<0.001). This may be of clinical concern because increased surface roughness has the potential to increase the wear of polyethylene liners articulating against these OxZr heads in THA. PMID:25443362

  18. Factors responsible for the development of avascular necrosis secondary to the treatment of congenital dislocation of the hip.

    PubMed

    Burgos-Flores, J; Ocete-Guzman, G; Gonzalez-Herranz, P; Hevia-Sierra, E; Amaya-Alarcon, S

    1993-11-01

    We present 104 cases of unilateral congenital dislocation of the hip treated with the same regime between 1977 and 1988. The patients had an average age of 12 months (range 4-24). The average age at follow-up was 6 years (range 3-13). The incidence of avascular necrosis was 37%. Avascular necrosis presented most frequently in babies of 7 months at the start of treatment, in Tonnis type IV when an adductor tenotomy was not performed, and after open reductions. The most influential factor was the absence of the femoral head descent at the end of the period of traction. The "effective" prereduction traction and the performance of an adductor tenotomy when necessary were the principle factors in avoiding avascular necrosis.

  19. [Congenital dysplasia and dislocation of the hip: proven and new procedures in diagnostics and therapy].

    PubMed

    Multerer, C; Döderlein, L

    2014-08-01

    As developmental dysplasia of the hip (DDH) is the most common congenital muskuloskeletal anomaly, it seems necessary to give an update on the normal growth, pathoanatomy, diagnostic and therapeutic procedures. Which investigations or procedures have withstood the test of time? What are new therapeutic strategies and considerations? What are the problems? Review of the current literature on DDH supplemented by several years experience in the treatment of this condition by the authors. We have still a long way to achieve the goal of agreement on universal standardization of assessment and treatment methods based on age and staging regarding DDH, as in the Ponseti treatment procedure for clubfoot. Our experiences, as well as the literature suggest the use of Graf's nomenclature for classification of DDH in the first year of life. If dynamic ultrasound (US) shows at least a partial relocation of a decentered hip in the first 6 weeks of life, splinting in human position is advocated. The treatment of a Graf type IV hip joint is very difficult and often need surgery. The established surgical procedures in the literature are still up to date. Radiological follow-up of the affected as well as the unaffected side until the end of the growth phase is mandatory due to the risk of residual dysplasia.

  20. Patterns of postural deformity in non-ambulant people with cerebral palsy: what is the relationship between the direction of scoliosis, direction of pelvic obliquity, direction of windswept hip deformity and side of hip dislocation?

    PubMed

    Porter, David; Michael, Shona; Kirkwood, Craig

    2007-12-01

    To investigate: (a) associations between the direction of scoliosis, direction of pelvic obliquity, direction of windswept deformity and side of hip subluxation/ dislocation in non-ambulant people with cerebral palsy; and (b) the lateral distribution of these postural asymmetries. Cross-sectional observational study. Posture management services in three centres in the UK. Non-ambulant people at level five on the gross motor function classification system for cerebral palsy. Direction of pelvic obliquity and lateral spinal curvature determined from physical examination, direction of windswept hip deformity derived from range of hip abduction/adduction, and presence/side of unilateral hip subluxation defined by hip migration percentage. A total of 747 participants were included in the study, aged 6-80 years (median 18 years 10 months). Associations between the direction of scoliosis and direction of pelvic obliquity, and between the direction of windswept hip deformity and side hip subluxation/dislocation were confirmed. A significant association was also seen between the direction of scoliosis and the direction of the windswept hip deformity (P<0.001) such that the convexity of the lateral spinal curve was more likely to be opposite to the direction of windsweeping. Furthermore, significantly more windswept deformities to the right (P=0.007), hips subluxed on the left (P=0.002) and lateral lumbar/lower thoracic spinal curves convex to the left (P=0.03) were observed. The individual asymmetrical postural deformities are not unrelated in terms of direction and not equally distributed to the left/right. A pattern of postural deformity was observed.

  1. Patterns of postural deformity in non-ambulant people with cerebral palsy: what is the relationship between the direction of scoliosis, direction of pelvic obliquity, direction of windswept hip deformity and side of hip dislocation?

    PubMed Central

    Michael, Shona; Kirkwood, Craig

    2008-01-01

    Objective: To investigate: (a) associations between the direction of scoliosis, direction of pelvic obliquity, direction of windswept deformity and side of hip subluxation/dislocation in non-ambulant people with cerebral palsy; and (b) the lateral distribution of these postural asymmetries. Design: Cross-sectional observational study. Setting: Posture management services in three centres in the UK. Subjects: Non-ambulant people at level five on the gross motor function classification system for cerebral palsy. Main measures: Direction of pelvic obliquity and lateral spinal curvature determined from physical examination, direction of windswept hip deformity derived from range of hip abduction/adduction, and presence/side of unilateral hip subluxation defined by hip migration percentage. Results: A total of 747 participants were included in the study, aged 6–80 years (median 18 years 10 months). Associations between the direction of scoliosis and direction of pelvic obliquity, and between the direction of windswept hip deformity and side hip subluxation/dislocation were confirmed. A significant association was also seen between the direction of scoliosis and the direction of the windswept hip deformity (P < 0.001) such that the convexity of the lateral spinal curve was more likely to be opposite to the direction of windsweeping. Furthermore, significantly more windswept deformities to the right (P = 0.007), hips subluxed on the left (P = 0.002) and lateral lumbar/lower thoracic spinal curves convex to the left (P = 0.03) were observed. Conclusions: The individual asymmetrical postural deformities are not unrelated in terms of direction and not equally distributed to the left/right. A pattern of postural deformity was observed. PMID:18042604

  2. Prevention of Dislocation Risk During Hip Revision Surgery with the Dual Mobility Concept; Study of a New Generation of Dual Mobility Cups.

    PubMed

    Dangin, Antoine; Boulat, Sandrine; Farizon, Frédéric; Philippot, Rémi

    2016-10-26

    Total hip arthroplasty (THA) is a common surgery presenting well-known failures that may require surgical revision. To reduce the risk of hip dislocation after revision THA, we hypothesize the interest of the use of a new generation dual mobility cup by evaluating its survival and complication rates. We analyzed the survival and the failures rate of 91 patients who underwent revision THAs with a specific dual mobility cup Novae® E TH (SERF, Décines-Charpieu, France). The surgical indication for revision THAs were: 59 aseptic loosening or insert advanced wear (61.5%), 10 recurrent dislocations (10.9%), and 22 deep infections (24.1%). All patients underwent the same surgical technique and received a clinical and radiological examination. Failure of the cup was defined as an aseptic loosening; all failures were reported. During the follow up, 17 patients died and five were unaccounted for. The mean follow-up of the 86 patients included was 33 months (0-71) with a mean age of 71 years (41-99) at the time of surgery. The Postel Merle D'Aubigné (PMA) increased by 6.8 points from preoperative until the last consultation. No aseptic loosening was reported. The postoperative dislocation rate was 3.5% and 4.6% for deep infections. The overall rate for re-revision THAs was 8.1%. New choice of design and coating for the cup have demonstrated good results to reduce the rate of aseptic loosening compared to other studies. The three hip dislocations concerned two patients who had a history of recurrent dislocation and psychiatric pathologies. The limit of the study is its short follow-up, partially explained by the occurrence of 10 deaths in the first year of follow-up (lowering the mean). The use of a cementless dual mobility tripod cup for revision THA confirms its place in the possible therapeutic range by its excellent results at medium term.

  3. Early articular cartilage degeneration in a developmental dislocation of the hip model results from activation of β-catenin

    PubMed Central

    Ning, Bo; Sun, Jun; Yuan, Yi; Yao, Jie; Wang, Peng; Ma, Ruixue

    2014-01-01

    Developmental dislocation or dysplasia of the hip (DDH) is one of the most common deformities in children. Osteoarthritis (OA) is the most frequent long-term complication. The molecular mechanism of early articular cartilage degeneration in DDH is still unclear. It is well known that β-catenin plays a crucial role in articular cartilage degeneration. The objective of this study was to verify the relationship between β-catenin and DDH cartilage degeneration. We used a DDH model that was established by modification of swaddling position in newborn Wistar rats. The hips were isolated from the DDH model rats and untreated control group at the age of 2, 4, 6 and 8 weeks. β-Catenin gene and protein were investigated by quantitative (q)RT-PCR and immunohistochemistry. Collagen X and matrix metalloproteinase (MMP)-13, markers of early cartilage degeneration, were assessed by qRT-PCR. Primary chondrocytes were cultured from cartilage of two groups at the age of 8 weeks. Expression of β-catenin, collagen X and MMP-13 was detected. Continued high expression of β-catenin was observed in cartilage from DDH model rats. mRNA and protein expression of β-catenin was significantly increased in primary chondrocytes of the DDH model compared with the control group. Collagen X and MMP-13 expression was higher in the cartilage and chondrocytes from DDH model rats than the control group. Our findings suggest that early cartilage degeneration in DDH may result from activation of β-catenin signaling. PMID:24817933

  4. The risk of revision due to dislocation after total hip arthroplasty depends on surgical approach, femoral head size, sex, and primary diagnosis

    PubMed Central

    2012-01-01

    Background and purpose The effects of patient-related and technical factors on the risk of revision due to dislocation after primary total hip arthroplasty (THA) are only partly understood. We hypothesized that increasing the femoral head size can reduce this risk, that the lateral surgical approach is associated with a lower risk than the posterior and minimally invasive approaches, and that gender and diagnosis influence the risk of revision due to dislocation. Patients and methods Data on 78,098 THAs in 61,743 patients performed between 2005 and 2010 were extracted from the Swedish Hip Arthroplasty Register. Inclusion criteria were a head size of 22, 28, 32, or 36 mm, or the use of a dual-mobility cup. The covariates age, sex, primary diagnosis, type of surgical approach, and head size were entered into Cox proportional hazards models in order to calculate the adjusted relative risk (RR) of revision due to dislocation, with 95% confidence intervals (CI). Results After a mean follow-up of 2.7 (0–6) years, 399 hips (0.5%) had been revised due to dislocation. The use of 22-mm femoral heads resulted in a higher risk of revision than the use of 28-mm heads (RR = 2.0, CI: 1.2–3.3). Only 1 of 287 dual-mobility cups had been revised due to dislocation. Compared with the direct lateral approach, minimally invasive approaches were associated with a higher risk of revision due to dislocation (RR = 4.2, CI: 2.3–7.7), as were posterior approaches (RR = 1.3, CI: 1.1–1.7). An increased risk of revision due to dislocation was found for the diagnoses femoral neck fracture (RR = 3.9, CI: 3.1–5.0) and osteonecrosis of the femoral head (RR = 3.7, CI: 2.5–5.5), whereas women were at lower risk than men (RR = 0.8, CI: 0.7–1.0). Restriction of the analysis to the first 6 months after the index procedure gave similar risk estimates. Interpretation Patients with femoral neck fracture or osteonecrosis of the femoral head are at higher risk of dislocation. Use of the

  5. The minimal invasive direct anterior approach in combination with large heads in total hip arthroplasty - is dislocation still a major issue? a case control study

    PubMed Central

    2014-01-01

    Background There have been increasing numbers of publications in recent years on minimally invasive surgery (MIS) for total hip arthroplasty (THA), reporting results with the use of different head sizes, tribologic and functional outcomes. This study presents the results and early complication rates after THA using the direct anterior approach (DAA) in combination with head sizes ≥ 36 mm. Methods A total of 113 patients with THA were included in the study. The Harris Hip Score (HHS) was determined, a radiographic evaluation was carried out, and complications were recorded. The minimum follow-up period was 2 years (means 35 ± 7 months). Results The HHS improved from 43.6 (± 12) to 88.2 (± 14; P < 0.01). One early infection occurred, one periprosthetic fracture, and three cases of aseptic stem loosening. No incorrect positioning of the implants was observed, and there were no dislocations. Conclusion THA with the minimally invasive DAA in combination with large heads is associated with good to very good functional results in the majority of cases. The complication rates are not increased. The rate of dislocation mainly as an complication of the first two years can be markedly reduced in particular. PMID:24621189

  6. No benefit on functional outcomes and dislocation rates by increasing head size to 36 mm in ceramic-on-ceramic total hip arthroplasty.

    PubMed

    Lu, Yu-Der; Yen, Shih-Hsiang; Kuo, Feng-Chih; Wang, Jun-Wen; Wang, Ching-Jen

    2015-12-01

    Ceramic-on-ceramic (COC) total hip arthroplasty (THA) has gained popularity since improvements in wear characteristics and longevity. Whether large ceramic femoral heads (≥36 mm) have increased postoperative range of motion (ROM) and a lower dislocation rate is not clear. This study aimed to compare functional outcomes and early complications between large-head (≥36 mm) and smaller-head (≤32 mm) COC prostheses with a minimum follow-up of 12 months. A total of 95 consecutive uncemented COC THAs were performed in 90 patients between January 2012 and July 2013. Of these, 49 patients (smaller-head group) received third generation and 41 patients (large-head group) received fourth generation COC prostheses. Harris hip score (HHS), Western Ontario and McMaster Universities Arthritis index (WOMAC), and ROM of the hip pre- and post-operatively were compared, as well as the presence of early complications. Postoperative HHSs (88.4 vs. 89.3, p = 0.34) and WOMAC scores (12.0 vs. 11.0, p = 0.111) were not different between the groups. Postoperative flexion ROM was lower in the smaller-head group (98.8° vs. 106.1°, p < 0.001), but there were no differences in extension, abduction, adduction, internal rotation, and external rotation. One patient in each group reported a grinding noise. There was one dislocation (1.9%) in the smaller-head group, and none in the large-head group (p = 0.371). No infections or loosening of the components occurred. Large-head COC articulation provided better flexion, but functional outcomes and early complications are similar to the smaller-head COC. Copyright © 2016 Chang Gung University. Published by Elsevier B.V. All rights reserved.

  7. [Spasm of the adductor muscles, pre-dislocation and dislocations of the hip joints in children and adolescents with cerebral palsy. Clinical observations on aetiology, pathogenesis, therapy and rehabilitation. Part I: The effect of open myotenotomy of the gracilis muscle and of the long and short adductor muscles in connection with total extrapelvine resection of the obturator nerve, on the hip joints and static function (author's transl)].

    PubMed

    Fettweis, E

    1979-02-01

    Spasm and contraction of the adductor muscles involve, on the one hand, danger in respect of the development of a dislocation of the hip, and are a serious impediment to a walking ability on the other. Hence, surgery is often necessary. The article reports on the results of consequent weakening of the adductor muscles as a result of open myotenotomy in association with complete extrapelvine resection of the obturator nerve. 27 patients were subjected to surgery--in most cases bilaterally--at an age between 2 years and 5 months and 18 years, with a follow-up period of up to 15 years. The study does not include patients with spastic dislocation of the hip in whom this method was applied on the non-dislocated side and on the dislocated side in combination with iliopsoas tenotomy. This method makes it possible to achieve regression of existing defective positions of the hip joints. In a few cases, the valgus position of the neck of the femur was corrected to some extent. In two patients it was not possible to prevent the progress of a developing dislocation of the hip. These results show that, whereas the adductor muscles represent an essential factor for the occurrence of a spastic dislocation of the hip, other forces are most probably also involved. In the majority of cases, results were favourable in respect of the static function, although in some cases the success became evident after several years only, especially in mentally retarded patients and in apathetic individuals. Important for therapeutic success is the follow-up. The principles of its therapy are thoroughly discussed. Surgery is indicated only in special cases. Indications must be observed very strictly, since the risk of excessive weakening of the adductor muscles should not be underestimated.

  8. Tapered stems one-third proximally coated have higher complication rates than cylindrical two-third coated stems in patients with high hip dislocation undergoing total hip arthroplasty with step-cut shortening osteotomy.

    PubMed

    Ozden, V Emre; Dikmen, G; Beksac, B; Tozun, I Remzi

    2017-06-01

    The results of cementless stems in total hip arthroplasty (THA) done because of congenital dislocation with step-cut osteotomy is not well known, particularly the influence of the design and the role of extent of porous coating. Therefore we performed a retrospective study to evaluate the mid to long-term results THA performed with a single type acetabular component and different geometry and fixation type stems with ceramic bearings in the setting of step-cut subtrochanteric osteotomy in high hip dislocated (HHD) patients. We asked if the stem type affect the outcomes in terms of (1) intra and postoperative complication rates (2) radiographic outcomes (3) prosthesis survival in step-cut subtrochanteric shortening osteotomy. The type of the stem, whether cylindrical or tapered does not affect the outcome if the femoral canal fit and fill is obtained and the step-cut femoral shortening osteotomy is primarily fixed. Forty-five hips in 35 patients with a mean follow up of 10 years (range, 7-14 years) were evaluated. The single type cementless cup was placed at the level of the true acetabulum, a step-cut shortening femoral osteotomy was performed and reconstruction was performed with two different types of tapered stem in twenty-two hips (Synergy™ and Image™ proximally coated, Smith and Nephew, Menphis, TN, USA) and one type of cylindrical stem (Echelon™ with 2/3 coated, Smith and Nephew, Menphis, TN, USA) in twenty-three hips. Harris hip scores (HHS) and a University of California Los Angeles (UCLA) activity scores were calculated for all patients and successive X-rays were evaluated regarding component loosening and osteolysis, along with complications related to bearing, step-cut osteotomy and stem types. Forty-one hips (91%) had good and excellent clinical outcome according to HHS. The mean UCLA activity scores improved from 3.2±0.6 points (range, 2-4) preoperatively to 6.3 points±0.5 (range, 5-7) at the latest follow-up. The mean femoral shortening was 36

  9. Developmental Dysplasia of the Hip

    MedlinePlus

    ... is a problem with the way a baby's hip joint forms before, during, or after birth — causing an unstable hip. In severe cases, the hip joint can dislocate or cause trouble walking. Mild cases ...

  10. Hip fracture surgeries

    MedlinePlus

    ... References Goulet JA. Hip dislocations. In: Browner BD, Jupiter JB, Krettek C, Anderson PA, eds. Skeletal Trauma: ... Baumgaertner MR. Intertrochanteric hip fractures. In: Browner BD, Jupiter JB, Krettek C, Anderson PA, eds. Skeletal Trauma: ...

  11. Hip Injuries and Disorders

    MedlinePlus

    ... or falling can all sometimes lead to hip injuries. These include Strains Bursitis Dislocations Fractures Certain diseases also lead to hip injuries or problems. Osteoarthritis can cause pain and limited ...

  12. Association between ASA grade and complication rate in patients receiving procedural sedation for relocation of dislocated hip prostheses in a UK emergency department.

    PubMed

    Dawson, Neil; Dewar, Alistair; Gray, Alasdair; Leal, Alexis

    2014-03-01

    To determine the association between the American Society of Anesthiologists (ASA) grade and the complication rate of patients receiving procedural sedation for relocation of hip prosthesis in an adult emergency department (ED) in the UK. Retrospective study of registry data from a large UK teaching hospital ED. Consecutive adult patients (aged 16 years and over) in whom ASA grade could be calculated, with an isolated dislocation of a hip prosthesis between 8 September 2006 and 16 April 2010 were included for analyses (n=303). The primary outcome measure was association between ASA and complication rate (any of desaturation <90%; apnoea; vomiting; aspiration; hypotension <90 mm Hg; cardiac arrest). Secondary outcome measures were relationship between ASA grade and procedural success, choice of sedative agent and sedation depth, and complications and choice of sedative agent, arrival time and sedation depth. There was no significant difference between ASA grade and the risk of complication (p=0.800). Moreover, there was no significant difference between ASA grade and procedural success (p=0.284), ASA and choice of sedative agent (p=0.243), or ASA and sedation depth (p=0.48). There was no association between complications and sedative agent (p=0.18), or complications and arrival time (p=0.12). There was a significant difference between sedative depth and complications (p<0.001). There is no clear association between a patient's physical status (ASA grade) and the risk of complications, chance of procedural success or choice of sedative agent in relocation of hip prostheses. There is a higher rate of complications with higher levels of sedation (p<0.001).

  13. No dislocations after primary hip arthroplasty with the dual mobility cup in displaced femoral neck fracture in patients with dementia. A one-year follow-up in 20 patients

    PubMed Central

    Graversen, Anders Elneff; Jakobsen, Stig Storgaard; Kristensen, Pia Kjær; Thillemann, Theis Muncholm

    2017-01-01

    Purpose: The aim of this study was to describe the dislocation rates, reoperation rates and mortality 30 day and one year following THA with AVANTAGE® dual mobility cup among dementia patients with an acute displaced intracapsular femoral neck fracture. Patients and methods: From 2010 to 2014 we identified 20 hip fracture patients with dementia, who have had total hip arthroplasty with the AVANTAGE® dual mobility cup. The primary outcome was dislocation. Secondary outcomes were revision surgery, 30 days and one year mortality, time to surgery and length of hospital stay. Results: Follow-up time was one year. None of the patients experienced dislocation or received revision surgery in the follow-up period. The 30-days mortality rate was 25% (confidence interval (CI) 95%; 4–46%) and the one year mortality was 45% (CI 95%; 21–69). Mean time to surgery was 27 h (CI 95%; 20–37 h) and mean length of hospital stay was 5.5 days (CI 95%; 4, 0–7, 6 days). Conclusion: THA with the dual-mobility cup seems favourable in the treatment of patients with a displaced femoral neck fracture and patients with dementia. Correct placement of the cup is pivotal and technically demanding. Not all orthopedic surgeons perform total hip arthroplasty while challenges regarding the logistics can be encountered since time to surgery is known to affect the mortality negatively. PMID:28176672

  14. [Bone reconstruction, leg length discrepancy, and dislocation rate in 52 Wagner revision total hip arthroplasties at 44-month follow-up].

    PubMed

    Boisgard, S; Moreau, P E; Tixier, H; Levai, J P

    2001-04-01

    dislocations and five revision procedures (three for cup loosening, two for femoral pivot instability). The functional outcome was similar to results reported in the literature, including the high frequency of limping that was caused by various factors (valgus prosthesis neck, leg length discrepancy, muscle deficits). Leg length discrepancies resulted from defective positioning or impaction at loading. Standard radiographic series allowed an assessment of stem impaction. Our low rate could be due to delayed weight bearing. La reconstruction of bone loss did not progress after 18 months and was independent of bone grafting, route of access, and the initial degree of loosening. The high frequency of dislocations with this type of implant can be prevented by horizontalization of the acetabulum and use of anti-dislocation inserts at the first intention revision. Our results with the Wagner prosthesis are satisfactory both clinically and radiographically. The two drawbacks of this implant (limping and dislocation), partly due to the design of the femoral stem, have led us to study a new implant that preserves good distal anchoring and optimizes the proximal biomechanics of the hip joint.

  15. [Elbow dislocation].

    PubMed

    de Pablo Márquez, B; Castillón Bernal, P; Bernaus Johnson, M C; Ibañez Aparicio, N M

    2017-03-09

    Elbow dislocation is the most frequent dislocation in the upper limb after shoulder dislocation. Closed reduction is feasible in outpatient care when there is no associated fracture. A review is presented of the different reduction procedures.

  16. [IMPACT OF SALTER INNOMINATE OSTEOTOMY ON ACETABULAR MORPHOLOGY AND DIRECTION IN DEVELOPMENTAL DISLOCATION OF THE HIP BY THREE-DIMENSIONAL COMPUTER TOMOGRAPHY].

    PubMed

    Jiang, Jun; Ren, Shuang; Liu, Min

    2015-11-01

    To investigate the impact of the Salter innominate osteotomy on the acetabular morphology and direction and the relationship between them in children with developmental dislocation of the hip (DDH) by three-dimensional CT. Between January 2013 and January 2015, 51 patients with unilateral DDH were treated. All patients were females with an average age of 2 years and 5 months (range, one year and 6 months to 5 years). All the patients underwent open reduction of the hip, Salter innominate osteotomy, proximal femoral osteotomy, and hip cast immobilization for treatment. The data of three-dimensional CT before surgery and at 1 week after surgery were measured and collected as follows: the anterior acetabular index (AAI), posterior acetabular index (PAI), axial acetabular index (AxAI), acetabular anteversion angle (AAA) of the acetabulum, and the distances of the forward, outward, and lateral rotation of the distal osteotomy fragments. The differences of AAI, PAI, AxAI, AAA between before and after surgeries were compared and the difference values of the data with significant difference results were calculated. The relationship between the difference values and the distances of three different rotation directions before and after surgeries were tested by Spearman correlation analysis. There were significant differences in the AAI, PAI, and AAA between before and after surgery (P < 0.05), but no significant difference was found in the AxAI between before and after surgery (t = 0.878, P = 0.384). The difference values of AAI, PAI, and AAA were (4.518 ± 4.601), (4.219 ± 6.660), and (3.919 ± 4.389)° respectively. The distances of the outward, lateral, and forward rotation of the distal osteotomy fragments after surgery were (0.420 ± 0.339), (2.440 ± 0.230), and (0.421 ± 0.311) cm. There was a significant correlation between the three different rotation directions and AAI difference (P < 0.05), especialy the outward rotation (r=0.981). There was a correlation between

  17. Kneecap dislocation

    MedlinePlus

    Use proper techniques when exercising or playing sports. Keep your knee strong and flexible. Some cases of knee dislocation may not be preventable, especially if physical factors make you more likely to dislocate your knee.

  18. Hip fusion as hip salvage procedure in cerebral palsy.

    PubMed

    Fucs, Patricia M De Moraes Barros; Yamada, Helder H

    2014-01-01

    The treatment of the spastic hip in Cerebral Palsy (CP) remains a challenge especially in cases of advance changes. Many options are available and the key for a good outcome is to find the best surgical procedure to an individualized patient. The hip fusion is one of the surgical options. The authors presented a group of spastic CP with painful chronic hip subluxation and dislocation treated with hip fusion with a mean follow-up period of 14.5 years. Surgical technique, post-operative management and outcomes were shown, also with the observations done regarding the evolution of the contralateral hip after the hip fusion. They concluded that the hip arthrodesis is an option for patients with spastic CP with painful subluxation or dislocated hips with the goal of pain relief maintain or improve functional status, and facilitating the care. The best candidate is a young ambulatory patient with normal contralateral hip and normal spinal alignment.

  19. Factors predisposing to dislocation of the Thompson hemiarthroplasty: 22 dislocations in 338 patients.

    PubMed

    Pajarinen, Jarkko; Savolainen, Vesa; Tulikoura, Ilkka; Lindahl, Jan; Hirvensalo, Eero

    2003-02-01

    In a series of 338 patients, we have retrospectively analyzed technical and anatomical factors, which may predispose to a dislocation of the Thompson hemiprosthesis. 22 patients (7%) had at least 1 dislocation during the 6-month follow-up. The most significant independent factor predisposing to dislocation was the use of a posterior approach (dislocation rate 16%). We examined the radiographs and data on operations in the 22 patients, using 79 random patients without dislocation as controls. Factors correlating with an increase in the incidence of dislocation were the length of the residual femoral neck > 0.5 cm in short patients (< 165 cm), and considerable change in the postoperative offset of the hip. Acetabular measurements showed no correlation to the dislocation. Our findings suggest that the main factors predicting dislocation are technical and not related to anatomical measurements.

  20. Total Hip Arthroplasty for Hip Fractures

    PubMed Central

    Monzón, Daniel Godoy; Iserson, Kenneth V.; Jauregui, José; Musso, Carlos; Piccaluga, Francisco; Buttaro, Martin

    2014-01-01

    Introduction: This study aimed to determine the dislocation and reoperation rate, functional outcomes, and the survival rate of the unique subset of very old but lucid and independent patients with hip fractures following a total hip arthroplasty (THA) and geriatric team-coordinated perioperative care. Method: Between 2000 and 2006, previously independent ambulatory patients ≥80 years old presenting with an intracapsular hip fracture were given THAs under the care of an integrated orthopedic surgery–geriatric service. Their fracture-related complications, ambulation, mental status, and survival were followed for 5 to 11 years postinjury. Results: Five years postinjury, 57 (61.3%) patients of the original study group were living. In all, 3 (3.2%) patients had postoperative hip dislocations (and 2 patients had dislocation twice) and 2 reoperations were needed within the first postoperative month. There were no hip dislocations or reoperations after the first year. Radiographs obtained on 88% of the surviving patients at 5 years postoperatively showed that all remained unchanged from their immediate postoperative images. Nearly half of the patients were still able to ambulate as they did preoperatively and their mixed-model equation was statistically unchanged. Conclusion: This study of patients >80 years old with previously good functional status demonstrates that with appropriate surgical (best prosthesis, good operating technique, and regional anesthesia) and geriatric (pre- and postoperative assessments, close follow-up, medication adjustments, and fall-prevention instruction) care, they have few hip dislocations and reoperations, survive postfracture at least as long as their noninjured contemporaries, and continue to function and ambulate as they did prior to their injury. PMID:24660092

  1. Fracture After Total Hip Replacement

    MedlinePlus

    ... er Total Hip Replacement cont. • Dislocation • Limb length inequality • Poor fracture healing • Repeat fracture • Lack of in- ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Page ( 5 ) AAOS does ...

  2. Total hip arthroplasty instability in Italy.

    PubMed

    Falez, Francesco; Papalia, Matteo; Favetti, Fabio; Panegrossi, Gabriele; Casella, Filippo; Mazzotta, Gianluca

    2017-03-01

    Hip dislocation is a major and common complication of total hip arthroplasty (THA), which appears with an incidence between 0.3% and 10% in primary total hip arthroplasties and up to 28% in revision THA. The hip dislocations can be classified into three groups: early, intermediate and late. Approximately two-thirds of cases can be treated successfully with a non-operative approach. The rest require further surgical intervention. The prerequisite to developing an appropriate treatment strategy is a thorough evaluation to identify the causes of the dislocation. In addition, many factors that contribute to THA dislocation are related to the surgical technique, mainly including component orientation, femoral head diameter, restoration of femoral offset and leg length, cam impingement and condition of the soft tissues. The diagnosis of a dislocated hip is relatively easy because the clinical situation is very typical. Having identified a dislocated hip, the first step is to perform a closed reduction of the implant. After reduction you must perform a computed tomography scan to evaluate the surgical options for treatment of recurrent dislocation that include: revision arthroplasty, modular components exchange, dual-mobility cups, large femoral heads, constrained cups, elimination of impingement and soft tissue procedures. The objective is to avoid further dislocation, a devastating event which is increasing the number of operations on the hip. To obtain this goal is useful to follow an algorithm of treatment, but the best treatment remains prevention.

  3. Arthroscopic treatment of unstable total hip replacement.

    PubMed

    Cuéllar, Ricardo; Aguinaga, Iñaki; Corcuera, Irene; Ponte, Juan; Usabiaga, Jaime

    2010-06-01

    Hip arthroscopy may be useful in the diagnosis and treatment of apparently well-implanted but unstable total hip replacement prostheses. We present 2 cases of arthroscopically assisted capsular tightening in unstable total hip replacements. Both cases had significant capsular laxity. Case 2 had impingement of the lower part of the acetabulum with the lesser trochanter that caused hip dislocation. Early revision surgery can be avoided with the use of this technique in selected cases of unstable total hip replacements.

  4. Developmental dysplasia of the hip

    MedlinePlus

    ... hip joint may help diagnose the condition in older infants and children. A hip that is truly dislocated ... the child grows. This harness works for most infants when it is started before age 6 months, but it is less likely to work for older children. Children who do not improve, or who ...

  5. Techniques and Results for Open Hip Preservation

    PubMed Central

    Levy, David M.; Hellman, Michael D.; Haughom, Bryan; Stover, Michael D.; Nho, Shane J.

    2015-01-01

    While hip arthroscopy grows in popularity, there are still many circumstances under which open hip preservation is the most appropriately indicated. This article specifically reviews open hip preservation procedures for a variety of hip conditions. Femoral acetabular impingement may be corrected using an open surgical hip dislocation. Acetabular dysplasia may be corrected using a periacetabular osteotomy. Acetabular protrusio may require surgical hip dislocation with rim trimming and a possible valgus intertrochanteric osteotomy. Legg–Calve–Perthes disease produces complex deformities that may be better served with osteotomies of the proximal femur and/or acetabulum. Chronic slipped capital femoral epiphysis may also benefit from a surgical hip dislocation and/or proximal femoral osteotomy. PMID:26649292

  6. [Congenital hip dysplasia, screening and therapy].

    PubMed

    Kolb, A; Windhager, R; Chiari, C

    2015-11-01

    Congenital hip dysplasia and hip dislocation are relatively common pathological conditions of the musculoskeletal system in infants. An early and certain diagnosis can now be achieved by sonographic hip screening within the framework of screening examination programs. This early diagnostic procedure in infants is essential particularly for a conservative treatment strategy. Therefore, apart from possessing in-depth knowledge, training of the examiner in specialist courses is of central importance. This article presents an overview of the entity of congenital hip dysplasia and hip dislocation, the diagnostics and treatment with special emphasis on recent developments.

  7. Pelvic Support Osteotomy; Salvage Procedure in Chronically Dislocated Hips Case Report: Technical Note on the On-lay Bone Positioning of a Lengthening Nail and Review of the Literature

    PubMed Central

    Reynders-Frederix, Pieter; Reynders-Frederix, Cristina; Wajid, Muhammad

    2016-01-01

    Background: Young patients with a acquired dislocation of the hip with concomitant shortening of the lower limb is a difficult diagnostic problem with few definite treatment options. Methods: We used the technique, originally described by Ilizarov, with a double femur osteotomy and lengthening the femur. Lengthening was done with a sub muscular placed on-lay femur distraction rod. Distraction of the rod was done by fluid mechanics. After lengthening, the distraction was secured by a parked plate by locking the distal part of the plate. Results: This patient needed a lengthening of 60 mm, distraction time was 36 days with a distraction index of 1.61 mm per day and a healing index of 31.4 days per cm lengthening.We encountered one complication in which an exchange of the plastic feeding tube was needed at 20 days post-surgery. Conclusions: In the reported case we could improve gait with reduced limping and equalizing her leg length discrepancy. PMID:27583056

  8. Hip pain

    MedlinePlus

    ... pain involves any pain in or around the hip joint. You may not feel pain from your hip ... 2012:chap 48. Read More Hip fracture surgery Hip joint replacement Patient Instructions Hip fracture - discharge Hip or ...

  9. Knee Dislocations

    PubMed Central

    Schenck, Robert C.; Richter, Dustin L.; Wascher, Daniel C.

    2014-01-01

    Background: Traumatic knee dislocation is becoming more prevalent because of improved recognition and increased exposure to high-energy trauma, but long-term results are lacking. Purpose: To present 2 cases with minimum 20-year follow-up and a review of the literature to illustrate some of the fundamental principles in the management of the dislocated knee. Study Design: Review and case reports. Methods: Two patients with knee dislocations who underwent multiligamentous knee reconstruction were reviewed, with a minimum 20-year follow-up. These patients were brought back for a clinical evaluation using both subjective and objective measures. Subjective measures include the following scales: Lysholm, Tegner activity, visual analog scale (VAS), Short Form–36 (SF-36), International Knee Documentation Committee (IKDC), and a psychosocial questionnaire. Objective measures included ligamentous examination, radiographic evaluation (including Telos stress radiographs), and physical therapy assessment of function and stability. Results: The mean follow-up was 22 years. One patient had a vascular injury requiring repair prior to ligament reconstruction. The average assessment scores were as follows: SF-36 physical health, 52; SF-36 mental health, 59; Lysholm, 92; IKDC, 86.5; VAS involved, 10.5 mm; and VAS uninvolved, 2.5 mm. Both patients had excellent stability and were functioning at high levels of activity for their age (eg, hiking, skydiving). Both patients had radiographic signs of arthritis, which lowered 1 subject’s IKDC score to “C.” Conclusion: Knee dislocations have rare long-term excellent results, and most intermediate-term studies show fair to good functional results. By following fundamental principles in the management of a dislocated knee, patients can be given the opportunity to function at high levels. Hopefully, continued advances in the evaluation and treatment of knee dislocations will improve the long-term outcomes for these patients in the

  10. Management of hip deformities in cerebral palsy.

    PubMed

    Valencia, Francisco G

    2010-10-01

    Hip abnormalities affect most children with cerebral palsy. Dedicated surveillance programs have been shown to be effective means of identifying hips at risk and preventing pathologic dislocation. Patients who are ambulatory and correlate with Gross Motor Function Classification Score I and II experience deformities that affect mobility and gait, but rarely dislocations. Marginal and nonambulatory patients have an increasing risk of dislocation. Once subluxation has been identified, early surgical intervention is indicated. Long-term postoperative follow-up is needed to monitor for recurrence. Individuals who recur or who do not respond to initial soft tissue releases benefit from bony surgery. Comprehensive reconstruction of the hip has become the predominant treatment approach when acetabular and proximal femoral dysplasia is present. The painful arthritic dislocated hip has numerous treatment options. Hip arthroplasty procedures show promising results and may supplant other salvage options in the future. Copyright © 2010. Published by Elsevier Inc.

  11. Simple Elbow Dislocation.

    PubMed

    Armstrong, April

    2015-11-01

    Simple elbow dislocation refers to those elbow dislocations that do not involve an osseous injury. A complex elbow dislocation refers to an elbow that has dislocated with an osseous injury. Most simple elbow dislocations are treated nonoperatively. Understanding the importance of the soft tissue injury following a simple elbow dislocation is a key to being successful with treatment.

  12. The use of hip arthroscopy in the management of the pediatric hip

    PubMed Central

    Roy, Dennis R.

    2016-01-01

    Arthroscopy of the pediatric hip began in 1977 with a publication by Gross. Interest was relatively slow to develop in the 1980s and 1990s. Coupled with the success of hip arthroscopy in the adult, interest heightened in applying the procedure to a variety of pediatric hip disorders, given that the alternative was an open surgical hip dislocation. The success of this initial group of pediatric hip arthroscopist’s has further expanded the application of hip arthroscopy as the primary or adjunct procedure for the management of intra-articular problems of the pediatric hip. PMID:27583144

  13. Reconstruction of the Acetabulum in Developmental Dysplasia of the Hip in total hip replacement

    PubMed Central

    Sakellariou, Vasileios I.; Christodoulou, Michael; Sasalos, Gregory; Babis, George C.

    2014-01-01

    Developmental dysplasia of the hip (DDH) or congenital hip dysplasia (CDH) is the most prevalent developmental childhood hip disorder. It includes a wide spectrum of hip abnormalities ranging from dysplasia to subluxation and complete dislocation of the hip joint. The natural history of neglected DDH in adults is highly variable. The mean age of onset of symptoms is 34.5 years for dysplastic DDH, 32.5 years for low dislocation, 31.2 years for high dislocation with a false acetabulum, and 46.4 years for high dislocation without a false acetabulum. Thorough understanding of the bony and soft tissue deformities induced by dysplasia is crucial for the success of total hip arthroplasty. It is important to evaluate the existing acetabular deformity three-dimensionally, and customize the correction in accordance with the quantity and location of ace tabular deficiencies. Acetabular reconstruction in patients with DDH is challenging. Interpretation of published data is difficult and should be done with caution because most series include patients with different types of hip disease. In general, the complication rate associated with THA is higher in patients with hip dysplasia than it is in patients with osteoarthritis. Overall, clinical and functional outcomes following THA in patients hip dysplasia (DDH) differ from those treated for primary hip osteoarthritis, possibly due to the lower age and level of activity. Although function scores decline with age, the scores for pain and range of motion presented with a statistically significant improvement in the long-term. PMID:25386570

  14. Congenital knee dislocation in a 49,XXXXY boy.

    PubMed Central

    Sijmons, R H; van Essen, A J; Visser, J D; Iprenburg, M; Nelck, G F; Vos-Bender, M L; de Jong, B

    1995-01-01

    We report on a 12 year old mentally retarded boy who presented at birth with bilateral knee dislocations, dislocation of the right hip, and general joint laxity. Cytogenetic studies showed a 49,XXXXY karyotype. Hyperlaxity of joints is known to occur in 49,XXXXY patients, but congenital knee dislocation has not been reported. Rarely in 49,XXXXY and 49,XXXXX syndromes Larsen-like features may be seen. Patients with congenital joint dislocation or laxity, combined with other malformations, especially if psychomotor development is delayed, should be karyotyped to exclude chromosomal abnormalities. Images PMID:7643364

  15. A Detailed Review of Hip Reduction Maneuvers: A Focus on Physician Safety and Introduction of the Waddell Technique

    PubMed Central

    Waddell, Bradford S.; Mohamed, Shafiq; Glomset, John Trey; Meyer, Mark S.

    2016-01-01

    Dislocation of the hip is a well-described event that occurs in conjunction with high-energy trauma or postoperatively after total hip arthroplasty. Bigelow first described closed treatment of a dislocated hip in 1870, and in the last decade many reduction techniques have been proposed. In this article, we review all described techniques for the reduction of hip dislocation while focusing on physician safety. Furthermore, we introduce a modified technique for the reduction of posterior hip dislocation that allows the physician to adhere to the back safety principles set for by the Occupational Safety and Health Administration. PMID:27114811

  16. Lateral subtalar dislocation.

    PubMed

    Sharda, Praveen; DuFosse, Julian

    2008-07-01

    Subtalar dislocations are rare in routine orthopedic practice. While many of these dislocations are a result of high-energy injuries such as fall from a height or traffic accidents, it is not uncommon for patients to present after slipping down a few stairs. Two types of dislocation have been described, medial and lateral. The type of dislocation is described according to the position of the foot. In lateral subtalar dislocation the head of talus is found medially and the calcaneus is dislocated laterally. The navicular may lie dorsolateral to the talus. The reverse is true of lateral dislocation. Medial dislocation has been referred to as "basketball foot" due to its preponderance in basketball players.4 The deciding factor is the inverted or everted position of the foot when the force is dissipated through the weak talonavicular and talocalcaneal ligaments. This article presents a case of an adult with lateral subtalar dislocation following a fall.

  17. Trochanteric osteotomy in total hip replacement for congenital hip disease.

    PubMed

    Hartofilakidis, G; Babis, G C; Georgiades, G; Kourlaba, G

    2011-05-01

    We studied the effect of trochanteric osteotomy in 192 total hip replacements in 140 patients with congenital hip disease. There was bony union in 158 hips (82%), fibrous union in 29 (15%) and nonunion in five (3%). The rate of union had a statistically significant relationship with the position of reattachment of the trochanter, which depended greatly on the pre-operative diagnosis. The pre-operative Trendelenburg gait substantially improved in all three disease types (dysplasia, low and high dislocation) and all four categories of reattachment position. A persistent Trendelenburg gait post-operatively was noticed mostly in patients with defective union (fibrous or nonunion). Acetabular and femoral loosening had a statistically significant relationship with defective union and the position of reattachment of the trochanter. These results suggest that the complications of trochanteric osteotomy in total hip replacement for patients with congenital hip disease are less important than the benefits of this surgical approach.

  18. Dislocation motion and instability

    NASA Astrophysics Data System (ADS)

    Zhu, Yichao; Chapman, Stephen Jonathan; Acharya, Amit

    2013-08-01

    The Peach-Koehler expression for the stress generated by a single (non-planar) curvilinear dislocation is evaluated to calculate the dislocation self stress. This is combined with a law of motion to give the self-induced motion of a general dislocation curve. A stability analysis of a rectilinear, uniformly translating dislocation is then performed. The dislocation is found to be susceptible to a helical instability, with the maximum growth rate occurring when the dislocation is almost, but not exactly, pure screw. The non-linear evolution of the instability is determined numerically, and implications for slip band formation and non-Schmid behavior in yielding are discussed.

  19. Continuity of dislocations

    SciTech Connect

    Bloomer, I.; Charap, J.M.

    1985-09-01

    Dislocation continuity is derived from the Bilby--Kondo theory of dislocations using exterior calculus. Dislocation density is represented by the torsion vector-valued two-form. Burgers vectors are associated with the vector part of the torsion while dislocation lines are associated with the two-form part. The exterior derivative of the torsion is shown to vanish when the crystal curvature vanishes. This implies two simultaneous continuity conditions: Burgers vector conservation and continuity of dislocation lines. On the other hand, dislocation continuity is violated when the curvature does not vanish. Since this can occur on grain boundaries it is inferred that grain boundaries are regions where crystal curvature is concentrated.

  20. Hip Pain

    MedlinePlus

    ... clues about the underlying cause. Problems within the hip joint itself tend to result in pain on the ... tendons and other soft tissues that surround your hip joint. Hip pain can sometimes be caused by diseases ...

  1. Anteromedial subtalar dislocation.

    PubMed

    Stafford, Harry; Boggess, Blake; Toth, Alison; Berkoff, David

    2013-01-25

    Subtalar dislocation is the simultaneous dislocation of the talocalcaneal and talonavicular joints of the foot, typically caused by falls from heights, twisting leg injuries and motor vehicle accidents. The dislocation can occur medially, lateral, anterior or posterior, but most commonly occurs from inversion injury producing a medial dislocation. These dislocations may be accompanied by fractures. Careful physical examination must be performed to assess for neurovascular compromise. Most subtalar dislocations can be treated with closed reduction under sedation. However, if the dislocation is associated with an open fracture it may require reduction in the operating room. Treatment should include postreduction plain x-ray and CT scan to evaluate for proper alignment and for fractures. This article presents a case of medial subtalar dislocation in a 23-year-old football player.

  2. [The hip joint in neuromuscular disorders].

    PubMed

    Strobl, W M

    2009-07-01

    Physiologic motor and biomechanical parameters are prerequisites for normal hip development and hip function. Disorders of muscle activity and lack of weight bearing due to neuromuscular diseases may cause clinical symptoms such as an unstable hip or reduced range of motion. Disability and handicap because of pain, hip dislocation, osteoarthritis, gait disorders, or problems in seating and positioning are dependent on the severity of the disease, the time of occurrence, and the means of prevention and treatment. Preservation of pain-free and stable hip joints should be gained by balancing muscular forces and by preventing progressive dislocation. Most important is the exact indication of therapeutic options such as movement and standing therapy as well as drugs and surgery.

  3. Relationship between flexible flat foot and developmental hip dysplasia.

    PubMed

    Ponce de León Samper, M C; Herrera Ortiz, G; Castellanos Mendoza, C

    2015-01-01

    To evaluate the possible relationship between flexible flat foot and developmental hip dysplasia in children between six and 15 years of age. Cross-sectional study including 65 patients that had undergone surgery due to residual hip dysplasia or hip dislocation and compared against 75 healthy patients. Flexible flat foot prevalence was measured in each group, with the results showing that 61% of the group with residual hip dysplasia or hip dislocation had this condition, vs. 12% in the healthy group. The statistical analysis shows that the chances of suffering from flexible flat foot, are five times greater in the hip dysplasia or hip dislocation group, than in the healthy group. There is no evidence in the literature showing a relationship between these two conditions, even though they have a common etiology. This study shows a potential measurable relation between this two conditions. Patients with hip dysplasia or dislocation may have a higher chance of presenting flexible flat foot during late childhood, adolescence and adulthood, a fact that suggests a relationship between these two pathologies. Also, patients who seek assistance for the first time because of a flexible flat foot condition without having been evaluated during the first year of life for hip dysplasia, would be better off if evaluated for residual hip dysplasia. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  4. Open surgical dislocation for the treatment of femoroacetabular impingement: past, present, and future.

    PubMed

    Peters, Christopher L; Stronach, Benjamin M; Pelt, Christopher E; Erickson, Jill A

    2012-01-01

    Femoroacetabular impingement results from a lack of clearance between the femoral neck and the acetabulum. This condition is most commonly seen in the young adult presenting with hip pain after activity. There have been rapid advancements in the understanding of femoroacetabular impingement to include diagnostic, imaging, and treatment options. An open surgical dislocation approach has been developed that offers a safe and effective method to dislocate the hip and allow direct visualization and full access to treat the often complex intra-articular pathologies of femoroacetabular impingement. The ultimate goal of treatment in carefully selected patients is relief of hip pain and preservation of the hip joint.

  5. DYSPLASIA OF HIP DEVELOPMENT: UPDATE

    PubMed Central

    Guarniero, Roberto

    2015-01-01

    The term “developmental dysplasia of the hip” (DDH) includes a wide spectrum of abnormalities that affect the hip during its growth, ranging from dysplasia to joint dislocation and going through different degrees of coxofemoral subluxation. The incidence of DDH is variable, and depends on a number of factors, including geographical location. Approximately one in 1,000 newborn infants may present hip dislocation and around 10 in 1,000 present hip instability. Brazil has an incidence of five per 1,000 in terms of findings of a positive Ortolani sign, which is the early clinical sign for detecting the disorder. The risk factors for DDH include: female sex, white skin color, primiparity, young mother, breech presentation at birth, family history, oligohydramnios, newborns with greater weight and height, and deformities of the feet or spine. Hip examinations should be routine for newborns, and should be emphasized in maternity units. Among newborns and infants, the diagnosis of DDH is preeminently clinical and is made using the Ortolani and Barlow maneuvers. Conventional radiography is of limited value for confirming the diagnosis of DDH among newborns, and ultrasound of the hip is the ideal examination. The treatment of DDH is challenging, both for pediatric orthopedists and for general practitioners. The objectives of the treatment include diagnosis as early as possible, joint reduction and stabilization of the hip in a secure position. Classically, treatment options are divided according to different age groups, at the time of diagnosis. PMID:27022528

  6. Complications in Hip Arthroscopy

    PubMed Central

    Nakano, Naoki; Khanduja, Vikas

    2016-01-01

    Summary Background Recent developments in hip arthroscopic techniques and technology have made it possible in many cases to avoid open surgical dislocation for treating a variety of pathology in the hip. Although early reports suggest favourable results’ using hip arthroscopy and it has been shown to be a relatively safe procedure, complications do exist and can sometimes lead to significant morbidity. Methods This is a review article. The aim of this manuscript is to present the most frequent and/or serious complications that could occur at or following hip arthroscopy and some guidelines to avoid these complications. Conclusion Most complications of hip arthroscopy are minor or transient but serious complications can occur as well. A lot of complication e.g. acetabular labral puncture go unreported. Appropriate education and training, precise and meticulous surgical technique with correct instrumentation, the right indication in the right patient and adherence to advice from mentors and experienced colleagues are all essential factors for a successful outcome. Level of evidence: V. PMID:28066747

  7. 'Inverse' temporomandibular joint dislocation.

    PubMed

    Alemán Navas, R M; Martínez Mendoza, M G

    2011-08-01

    Temporomandibular joint (TMJ) dislocation can be classified into four groups (anterior, posterior, lateral, and superior) depending on the direction of displacement and the location of the condylar head. All the groups are rare except for anterior dislocation. 'Inverse' TMJ dislocation is a bilateral anterior and superior dislocation with impaction of the mandible over the maxilla; to the authors' knowledge only two cases have previously been reported in the literature. Inverse TMJ dislocation has unique clinical and radiographic findings, which are described for this case. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Nonarthroplasty hip surgery for early osteoarthritis.

    PubMed

    Kim, Young-Jo

    2008-08-01

    Subtle anatomic abnormalities of the hip, such as acetabular retroversion, acetabular overcoverage, and decreased head-neck offset of the femoral head-neck junction, are important anatomic variants that may lead to pain and osteoarthritis in the young adult population. Advances in surgical techniques, such as the periacetabular osteotomy, safe surgical dislocation of the hip, and hip arthroscopy, are providing us with more effective and safer tools to correct these anatomic problems. The limiting factor in treatment outcome in many mechanically compromised hips is the amount of cartilage damage that has occurred before treatment. This article is a guide to these subtle anatomic abnormalities and the options for treatment.

  9. Magnetic resonance imaging of hip joint cartilage and labrum

    PubMed Central

    Zilkens, Christoph; Miese, Falk; Jäger, Marcus; Bittersohl, Bernd; Krauspe, Rüdiger

    2011-01-01

    Hip joint instability and impingement are the most common biomechanical risk factors that put the hip joint at risk to develop premature osteoarthritis. Several surgical procedures like periacetabular osteotomy for hip dysplasia or hip arthroscopy or safe surgical hip dislocation for femoroacetabular impingement aim at restoring the hip anatomy. However, the success of joint preserving surgical procedures is limited by the amount of pre-existing cartilage damage. Biochemically sensitive MRI techniques like delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) might help to monitor the effect of surgical or non-surgical procedures in the effort to halt or even reverse joint damage. PMID:22053256

  10. Pure Intrathoracic Scapular Dislocation.

    PubMed

    Demirkiran, Nihat Demirhan; Kar, Adem

    2016-01-01

    Scapular dislocation, also known as locked scapula or scapulothoracic dislocation, is a rare entity that can be identified as extrathoracic or intrathoracic dislocation, depending on the penetration of the scapula into the thoracic cavity. The 3 reported cases of intrathoracic scapular dislocations in the literature are associated with a preexisting condition, such as sternoclavicular separation, prior rib fracture, thoracotomy for a lung transplant procedure, or surgical resection of superior ribs during breast or pulmonary tumor excisions. There are also 3 published cases of intrathoracic scapular impaction, involving comminuted scapular fractures with intrathoracic impaction of the inferior fragment through intercostal space. We report an intrathoracic scapular dislocation that was not associated with fracture of the scapula or predisposing factors. To our knowledge, this is the first case of pure intrathoracic dislocation.

  11. Late instability following total hip arthroplasty.

    PubMed

    Pulido, Luis; Restrepo, Camilo; Parvizi, Javad

    2007-06-01

    Instability is one of the most common complications after total hip arthroplasty and can present early or late after hip replacement. Late instability is considered if the event occurs five or more years after the primary arthroplasty, and in contrast to early dislocation, it appears to require operative intervention. The incidence of late instability may be greater than initially appreciated, and the cumulative rate rises with longer follow-up. The etiology of hip instability is often multifactorial with the presumed risk factors for late instability including long standing malposition of the components, trauma, deterioration in muscle mass, neurological status impairment and polyethylene wear. This article presents a synopsis of published studies on late instability and outlines our institutional experience with treatment of late dislocation following total hip arthroplasty occurring due to polyethylene wear.

  12. Irreducible posterolateral elbow dislocation.

    PubMed

    Atkinson, Cameron T; Pappas, Nick D; Lee, Donald H

    2014-02-01

    Elbow dislocations are a high-energy traumatic event resulting in loss of congruence of a stable joint. The majority of elbow dislocations can be reduced by closed means and treated conservatively. We present a case of an irreducible elbow dislocation with reduction blocked by the radial head buttonholed through the lateral ligamentous complex. We performed open reduction with release followed by repair of the lateral ligamentous complex. Clinicians need to understand this unique variant of an elbow dislocation to appropriately treat this operative injury.

  13. Dislocated shoulder - aftercare

    MedlinePlus

    ... aftercare; Shoulder subluxation - aftercare; Shoulder reduction - aftercare; Glenohumeral joint dislocation ... that connect bone to bone) of the shoulder joint. All of these tissues help keep your arm ...

  14. Bilateral Anterior Shoulder Dislocation

    PubMed Central

    Siu, Yuk Chuen; Lui, Tun Hing

    2014-01-01

    Introduction: Unilateral anterior shoulder dislocation is one of the most common problems encountered in orthopedic practice. However, simultaneous bilateral anterior dislocation of the shoulders is quite rare. Case Presentation: We report a case of a 75-year-old woman presented with simultaneous bilateral anterior shoulder dislocation following a trauma, complicated with a traction injury to the posterior cord of the brachial plexus. Conclusions: Bilateral anterior shoulder dislocation is very rare. The excessive traction force during closed reduction may lead to nerve palsy. Clear documentation of neurovascular status and adequate imaging before and after a reduction should be performed. PMID:25685749

  15. Discrete dislocations in graphene

    NASA Astrophysics Data System (ADS)

    Ariza, M. P.; Ortiz, M.

    2010-05-01

    In this work, we present an application of the theory of discrete dislocations of Ariza and Ortiz (2005) to the analysis of dislocations in graphene. Specifically, we discuss the specialization of the theory to graphene and its further specialization to the force-constant model of Aizawa et al. (1990). The ability of the discrete-dislocation theory to predict dislocation core structures and energies is critically assessed for periodic arrangements of dislocation dipoles and quadrupoles. We show that, with the aid of the discrete Fourier transform, those problems are amenable to exact solution within the discrete-dislocation theory, which confers the theory a distinct advantage over conventional atomistic models. The discrete dislocations exhibit 5-7 ring core structures that are consistent with observation and result in dislocation energies that fall within the range of prediction of other models. The asymptotic behavior of dilute distributions of dislocations is characterized analytically in terms of a discrete prelogarithmic energy tensor. Explicit expressions for this discrete prelogarithmic energy tensor are provided up to quadratures.

  16. Hip Fracture

    MedlinePlus

    ... make older people more likely to trip and fall — one of the most common causes of hip ... Taking steps to maintain bone density and avoid falls can help prevent hip fracture. Signs and symptoms ...

  17. Rose Hip

    MedlinePlus

    ... with your health provider.AspirinThe body breaks down aspirin to get rid of it. Rose hip contains ... of vitamin C might decrease the breakdown of aspirin. Taking large amount of rose hip along with ...

  18. Hip Replacement

    MedlinePlus

    ... exercise can reduce stiffness and increase flexibility and muscle strength. People who have an artificial hip should talk ... and cross-country skiing. These exercises can increase muscle strength and cardiovascular fitness without injuring the new hip. ...

  19. Hip Replacement

    MedlinePlus

    ... replacement is an operation in which a damaged hip joint is removed and replaced with an artificial joint. ... are many medical conditions that can damage the hip joint. (Watch the video to learn about what goes ...

  20. Hip Ultrasound

    MedlinePlus

    ... Index A-Z Hip Ultrasound Hip ultrasound uses sound waves to produce pictures of muscles, tendons, ligaments, ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  1. Framing Hip Hop: New Methodologies for New Times

    ERIC Educational Resources Information Center

    Dimitriadis, Greg

    2015-01-01

    This article revisits the central impulse behind early advocacy for ethnographic approaches to hip hop--that critics should try as much as possible to limit their own certainties around what hip hop can and might mean. While ethnographic approaches can engender the kinds of personal dislocations that allow for this negotiation, they do not…

  2. Framing Hip Hop: New Methodologies for New Times

    ERIC Educational Resources Information Center

    Dimitriadis, Greg

    2015-01-01

    This article revisits the central impulse behind early advocacy for ethnographic approaches to hip hop--that critics should try as much as possible to limit their own certainties around what hip hop can and might mean. While ethnographic approaches can engender the kinds of personal dislocations that allow for this negotiation, they do not…

  3. Metallurgy: Starting and stopping dislocations

    NASA Astrophysics Data System (ADS)

    Minor, Andrew M.

    2015-09-01

    A comparison of dislocation dynamics in two hexagonal close-packed metals has revealed that dislocation movement can vary substantially in materials with the same crystal structure, associated with how the dislocations relax when stationary.

  4. Traumatic vertical atlantoaxial dislocation.

    PubMed

    Payer, M; Wetzel, S; Kelekis, A; Jenny, B

    2005-08-01

    We present a case of traumatic vertical atlantoaxial dislocation of 16 millimetres with a fatal outcome. We hypothesize that this extremely rare traumatic vertical atlantoaxial dislocation results from insufficiency of the C1/C2 facet capsules after rupture of the tectorial membrane and the alar ligaments.

  5. Traumatic proximal tibiofibular dislocation.

    PubMed

    Burgos, J; Alvarez-Montero, R; Gonzalez-Herranz, P; Rapariz, J M

    1997-01-01

    Proximal tibiofibular dislocation is an exceptional lesion. Rarer still is its presentation in childhood. We describe the clinical case of a 6-year-old boy, the victim of a road accident. He had a tibiofibular dislocation associated with a metaphyseal fracture of the tibia.

  6. Parallel Dislocation Simulator

    SciTech Connect

    2006-10-30

    ParaDiS is software capable of simulating the motion, evolution, and interaction of dislocation networks in single crystals using massively parallel computer architectures. The software is capable of outputting the stress-strain response of a single crystal whose plastic deformation is controlled by the dislocation processes.

  7. Two-stage revision of hip prosthesis infection using a hip spacer with stabilising proximal cementation.

    PubMed

    Gil Gonzalez, Sergi; Marqués López, Fernando; Rigol Ramon, Pau; Mestre Cortadellas, Carlos; Cáceres Palou, Enric; León García, Alfonso

    2010-01-01

    Two-stage revision hip arthroplasty for infection using an antibiotic-loaded cement spacer has been used frequently with good results. However, spacer instability is also frequent. Proximal cementation of the spacer could avoid spacer dislocation. We retrospectively assessed 35 patients in whom a 2-stage revision hip arthroplasty for infection was carried out using an antibiotic-loaded cement spacer with gentamicin (Spacer-G) in which the spacer was proximally cemented in 16 patients. The mean follow-up was 32 months. We assessed spacer stability and infection elimination. There were 8 spacer dislocations (22.9%), 5 in hips without proximal cementation and 2 in hips with proximal cementation (p>0.05). There was no fracture in any hip. Reinfection occurred in 5 hips (14.3%), in 3 with the same microorganism, while 2 had a different microorganism. Our results indicate that the proximal cementation of the spacer prevents its dislocation. Infection was eliminated in 86% of the hips.

  8. Electronic properties of dislocations

    NASA Astrophysics Data System (ADS)

    Reiche, M.; Kittler, M.; Uebensee, H.; Pippel, E.; Haehnel, A.; Birner, S.

    2016-04-01

    Dislocations exhibit a number of exceptional electronic properties resulting in a significant increase in the drain current of MOSFETs if defined numbers of these defects are placed in the channel. Measurements on individual dislocations in Si refer to a supermetallic conductivity. A model of the electronic structure of dislocations is proposed based on experimental measurements and tight-binding simulations. It is shown that the high strain level on the dislocation core—exceeding 10 % or more—causes locally dramatic changes in the band structure and results in the formation of a quantum well along the dislocation line. This explains experimental findings (two-dimensional electron gas, single-electron transitions). The energy quantization within the quantum well is most important for supermetallic conductivity.

  9. Electromechanical simulations of dislocations

    NASA Astrophysics Data System (ADS)

    Skiba, Oxana; Gracie, Robert; Potapenko, Stanislav

    2013-04-01

    Improving the reliability of micro-electronic devices depends in part on developing a more in-depth understanding of dislocations because dislocations are barriers to charge carriers. To this end, the quasi-static simulation of discrete dislocations dynamics in materials under mechanical and electrical loads is presented. The simulations are based on the extended finite element method, where dislocations are modelled as internal discontinuities. The strong and weak forms of the boundary value problem for the coupled system are presented. The computation of the Peach-Koehler force using the J-integral is discussed. Examples to illustrate the accuracy of the simulations are presented. The motion of the network of the dislocations under different electrical and mechanical loads is simulated. It was shown that even in weak piezoelectric materials the effect of the electric field on plastic behaviour is significant.

  10. Evaluation of the hip center in total hip arthroplasty for old developmental dysplasia.

    PubMed

    Flecher, Xavier; Parratte, Sebastien; Brassart, Nicolas; Aubaniac, Jean-Manuel; Argenson, Jean-Noël

    2008-12-01

    We describe the problems with positioning the hip center according to the severity of dislocation in 97 cementless total hip arthroplasty for developmental dysplasia of the hip. The mean location of the hip center from the interteardrop was 30.4 +/- 8.7 mm horizontally and 23.4 +/- 5.4 mm vertically. The presence of a limp correlated with a superior placement of the cup. Four cups were revised, 2 of which with a significant high hip center. The survival rate of the acetabular component was 95% at 12 years. Craniopodal repositioning was easy in class 1. In class 2, the cup was the largest. In class 3, the greatest variations of the hip center were found. In class 4, the smallest implants were necessary for positioning in the true acetabulum.

  11. Effects of hip posture on the frontal impact tolerance of the human hip joint.

    PubMed

    Rupp, Jonathan D; Reed, Matthew P; Jeffreys, Thomas A; Schneider, Lawrence W

    2003-10-01

    The pattern of left- and right-side hip injuries to front-seat occupants involved in offset and angled frontal crashes suggests that hip posture (i.e., the orientation of the femur relative to the pelvis) affects the fracture/dislocation tolerance of the hip joint to forces transmitted along the femur during knee-to-knee-bolster loading in frontal impacts. To investigate this hypothesis, dynamic hip tolerance tests were conducted on the left and right hips of 22 unembalmed cadavers. In these tests, the knee was dynamically loaded in the direction of the long axis of the femur and the pelvis was fixed to minimize inertial effects. Thirty-five successful hip tolerance tests were conducted. Twenty-five of these tests were performed with the hip oriented in a typical posture for a seated driver, or neutral posture, to provide a baseline measure of hip tolerance. The effects of hip posture on hip tolerance were quantified using a paired-comparison experimental design. In six pairs of tests, one side of each cadaver was tested with the hip joint oriented in the neutral posture and the contralateral hip from the same cadaver was tested with the hip joint adducted 10 degrees from the neutral posture. In four pairs of tests, the hip was tested in neutral and 30 degrees flexed postures. The average fracture tolerance of the hip in the neutral posture was 6.1-/+1.5 kN. Hip tolerance decreased by an average of 34-/+4% with 30 degrees of flexion from the neutral posture (p<0.0001) and by 18-/+8% with 10 degrees of adduction from the neutral posture (p=0.008).

  12. Galeazzi fracture-dislocations.

    PubMed

    Mikić, Z D

    1975-12-01

    Among 125 patients with the Galeazzi-type fracture-dislocation of the forearm, there were fourteen children and eighty-six adults with the classic Galeazzi lesion, and twenty-five patients with a special type -- fracture of both bones and dislocation of the distal radio-ulnar joint. Conservative management was successful only in children. In adults this method resulted in failure in 80 per cent of cases. The results of operative treatment were much better. The fracture fragments of the radius and the dislocation of the radio-ulnar joint in this complex injury are very unstable, especially in the lesion with fractures of the radius and ulna, and it appears that rigid internal fixation is necessary for the dislocation as well as the fracture. With combined fixation over half of the results were excellent.

  13. Hip arthroscopy.

    PubMed

    de Amorim Cabrita, Henrique Antônio Berwanger; de Castro Trindade, Christiano Augusto; de Campos Gurgel, Henrique Melo; Leal, Rafael Demura; de Souza Marques, Ricardo da Fonseca

    2015-01-01

    Hip arthroscopy is a safe method for treating a variety of pathological conditions that were unknown until a decade ago. Femoroacetabular impingement is the commonest of these pathological conditions and the one with the best results when treated early on. The instruments and surgical technique for hip arthroscopy continue to evolve. New indications for hip arthroscopy has been studied as the ligamentum teres injuries, capsular repair in instabilities, dissection of the sciatic nerve and repair of gluteal muscles tears (injuries to the hip rotator cuff), although still with debatable reproducibility. The complication rate is low, and ever-better results with fewer complications should be expected with the progression of the learning curve.

  14. Intra-operative femoral neck fracture during attempted dislocation of a reduced hemi-arthroplasty.

    PubMed

    Ling, Samuel Ka Kin; Ma, Chun Man; Lui, Tun Hing

    2015-05-01

    Fragility hip fractures are increasingly common and hemiarthroplasty is one of the standard treatments. Although a common surgery, it should be performed with great caution because of the poor premorbid and bone quality in this demographic. Intra-operative fractures can occur while attempting press fit of the femoral implant. However; vigilance often steps down once the implant is secured and the hip reduced. This case report reminds surgeons that a large amount of torque can be transmitted during intra-operative positioning, such as during an attempt of hip dislocation. This torque, in addition to the risk factor of osteoporotic bone, can result in iatrogenic fractures. Published literature regarding management of an intra-operative fracture while the prosthetic hip is still reduced is lacking. The authors propose that temporary prophylactic cerclage wiring is a prudent and safe procedure prior to hip dislocation.

  15. Dual mobility total hip replacement in a high risk population

    PubMed Central

    Luthra, Jatinder Singh; Al Riyami, Amur; Allami, Mohamad Kasim

    2016-01-01

    Objective: The purpose of the study was to evaluate results of dual mobility total replacement in a high risk population who take hip into hyperflexed position while sitting and praying on the floor. Method: The study included 65 (35 primary total replacement and 30 complex total hip replacement) cases of total hip replacement using avantage privilege dual mobility cup system from biomet. A cemented acetabular component and on femoral side a bimetric stem, either cemented or uncemented used depending on the canal type. Ten cases were examined fluoroscopically in follow up. Result: There was dislocation in one patient undergoing complex hip replacement. Fluoroscopy study showed no impingement between the neck of prosthesis and acetabular shell at extremes of all movements. Conclusion: The prevalence of dislocation is low in our high risk population and we consider it preferred concept for patients undergoing complex total hip replacement. PMID:27924742

  16. Etomidate-facilitated hip reduction in the emergency department

    PubMed

    Dursteler; Wightman

    2000-10-01

    OBJECTIVE: The authors report what they believe is the first reported use of etomidate to assist in the reduction of a major joint in an outpatient setting. METHODS: The authors review the case of an elderly woman with a total hip arthroplasty who experienced four spontaneous posterior hip dislocations in a 5-month period. Etomidate was successfully used in two dislocations where previous methods had failed. RESULTS: A 68-year-old woman, who 13 months earlier had an uncomplicated total left hip replacement, was transported to the same ED on four separate occasions for a spontaneous left hip dislocation. Radiographs in each instance were significant only for a posterior dislocation of the implant articulation. The first reduction in the ED was unsuccessful and required a closed reduction in the operating theater. Seventy-two hours later the second dislocation and subsequent reduction occurred in the ED using etomidate to facilitate muscle relaxation. The patient was subsequently discharged home. Similar scenarios were replayed in the next few months. CONCLUSIONS: Muscle relaxation is the key characteristic for the reduction of dislocated major joints. The risks of respiratory depression and hemodynamic alterations with sedation are not insignificant, especially at the extremes of age. In the present case, intravenous narcotics and sedative-amnestic agents did not result in sufficient muscle relaxation. Larger or repeated doses may have resulted in undesirable or dangerous side effects. Etomidate is a useful adjunct when cardiopulmonary disease is present. The rapid onset and recovery from etomidate make it an excellent choice for facilitating the reduction of hip dislocations in elderly patients with prior total hip replacements.

  17. Management of hip disorders in patients with cerebral palsy.

    PubMed

    Flynn, John M; Miller, Freeman

    2002-01-01

    Hip disorders are common in patients with cerebral palsy and cover a wide clinical spectrum, from the hip at risk to subluxation, dislocation, and dislocation with degeneration and pain. Although the hip is normal at birth, a combination of muscle imbalance and bony deformity leads to progressive dysplasia. The spasticity or contracture usually involves the adductor and iliopsoas muscles; thus, the majority of hips subluxate in a posterosuperior direction. Many patients with untreated dislocations develop pain by early adulthood. Because physical examination alone is unreliable, an anteroposterior radiograph of the pelvis is required for diagnosis. Soft-tissue lengthening is recommended for children as soon as discernable hip subluxation (hip abduction <30 degrees, migration index >25%) is recognized. One-stage comprehensive hip reconstruction is effective treatment for children 4 years of age or older who have a migration index >60% but who have not yet developed advanced degenerative changes of the femoral head. Salvage options for the skeletally mature patient with a neglected hip are limited.

  18. Could larger diameter of 4th generation ceramic bearing decrease the rate of dislocation after THA?

    PubMed

    Lee, Young-Kyun; Ha, Yong-Chan; Jo, Woo-Lam; Kim, Tae-Young; Jung, Woon-Hwa; Koo, Kyung-Hoi

    2016-05-01

    Fourth generation (Delta) ceramic bearing was developed to reduce dislocation after total hip arthroplasty (THA) by increasing the head diameter. We tested a hypothesis that 32/36 mm Delta ceramic bearing decreases the dislocation rate. We also evaluated ceramic-related complications and early outcome of this thin liner-on-large head ceramic bearing. We performed a prospective study on patients who underwent THA with use of 32/36 mm Delta ceramic bearing. The dislocation rate was compared with the historical dislocation rate of third generation 28 mm ceramic bearing. We also evaluated ceramic fracture, squeak, short-term results and survival. Follow-up period was minimum 2 years. Between April 2010 and February 2012, we enrolled 250 consecutive patients (278 hips). All patients received cementless prostheses. Four patients (4 hips) who received metal shells ≤ 46 mm and 28 mm heads were excluded. Three patients died and 2 patients were lost within 2 years. The remaining 241 patients (269 hips) were followed for 24-46 months. There were 142 men (161 hips) and 99 women (108 hips) with a mean age of 53.7 years (range, 17-75 years) at the index operation. Dislocation occurred in three hips (1.1%). An old age was a risk factor for dislocation. Ceramic fracture and squeaking did not occur in any patient. Mean Harris hip score was 90.3 points at the latest follow-up. All acetabular and femoral components had bone-ingrowth stability. No hip had detectable wear or osteolysis. The survival was 99.3% in the best case scenario and 97.8% in the worst at 48 months. Total hip arthroplasty with use of 32/36 mm Delta ceramic bearing showed lower incidence of hip dislocation compared with 28 mm third generation ceramic bearing. A caution should be paid to prevent a fall in senile patients even though a large head is used. The short-term results of THA with this type of ceramic articulation are encouraging and we did not find any ceramic-related complications. Copyright

  19. MAASH Technique for Total Hip Arthroplasty: A Capsular Work.

    PubMed

    Delgado, Felipe G; Broch, Albert; Reina, Francisco; Ximeno, Lluís; Torras, David; García, Francesc; Salvador, Antoni

    2013-07-01

    Dislocation and leg length discrepancy are major complications following total hip arthroplasty (THA). Many surgical approaches for THA have been described, but none suggest a capsular incision that assures good exposure while maintaining adequate capsule integrity in closure. Modified anterolateral approach for stable hip (MAASH) is a modification of the classical Hardinge approach, but specifically preserves the anterior iliofemoral lateral ligament and pubofemoral ligament excising the "weak area" of the capsule, in the so called "internervous safe zone" and introducing the "box concept" for the anterior approach to the hip. This is the main difference of the MAASH approach. This technique can be used as a standard for all THA standard models, but we introduce new devices to make it easier. From November 2007 to May 2012, data were collected for this observational retrospective consecutive case study. We report the results of 100 THA cases corresponding to the development curve of this new concept in THA technique. MAASH technique offers to hip surgeons, a reliable and reproducible THA anterolateral technique assuring accurate reconstruction of leg length and a low rate of dislocation. Only one dislocation and six major complications are reported, but most of them occurred at the early stages of technique development. MAASH technique proposes a novel concept on working with the anterior capsule of the hip for the anterolateral approach in total hip arthroplasty, as well as for hemiarthroplasty in the elderly population with high dislocation risk factors. MAASH offers maximal stability and the ability to restore leg length accurately.

  20. Current Concepts in Hip Preservation Surgery

    PubMed Central

    Adler, Kelly L.; Cook, P. Christopher; Yen, Yi-Meng; Giordano, Brian D.

    2015-01-01

    Context: An evolution in conceptual understanding, coupled with technical innovations, has enabled hip preservation surgeons to address complex pathomorphologies about the hip joint to reduce pain, optimize function, and potentially increase the longevity of the native hip joint. Technical aspects of hip preservation surgeries are diverse and range from isolated arthroscopic or open procedures to hybrid procedures that combine the advantages of arthroscopy with open surgical dislocation, pelvic and/or proximal femoral osteotomy, and biologic treatments for cartilage restoration. Evidence Acquisition: PubMed and CINAHL databases were searched to identify relevant scientific and review articles from January 1920 to January 2015 using the search terms hip preservation, labrum, surgical dislocation, femoroacetabular impingement, peri-acetabular osteotomy, and rotational osteotomy. Reference lists of included articles were reviewed to locate additional references of interest. Study Design: Clinical review. Level of Evidence: Level 4. Results: Thoughtful individualized surgical procedures are available to optimize the femoroacetabular joint in the presence of hip dysfunction. Conclusion: A comprehensive understanding of the relationship between femoral and pelvic orientation, morphology, and the development of intra-articular abnormalities is necessary to formulate a patient-specific approach to treatment with potential for a successful long-term result. PMID:26502445

  1. Dislocations in complex materials.

    PubMed

    Chisholm, Matthew F; Kumar, Sharvan; Hazzledine, Peter

    2005-02-04

    Deformation of metals and alloys by dislocations gliding between well-separated slip planes is a well-understood process, but most crystal structures do not possess such simple geometric arrangements. Examples are the Laves phases, the most common class of intermetallic compounds and exist with ordered cubic, hexagonal, and rhombohedral structures. These compounds are usually brittle at low temperatures, and transformation from one structure to another is slow. On the basis of geometric and energetic considerations, a dislocation-based mechanism consisting of two shears in different directions on adjacent atomic planes has been used to explain both deformation and phase transformations in this class of materials. We report direct observations made by Z-contrast atomic resolution microscopy of stacking faults and dislocation cores in the Laves phase Cr2Hf. These results show that this complex dislocation scheme does indeed operate in this material. Knowledge gained of the dislocation core structure will enable improved understanding of deformation mechanisms and phase transformation kinetics in this and other complex structures.

  2. Ceramic-on-ceramic bearing decreases the cumulative long-term risk of dislocation.

    PubMed

    Hernigou, Philippe; Homma, Yasuhiro; Pidet, Olivier; Guissou, Isaac; Hernigou, Jacques

    2013-12-01

    It is unclear whether late THA dislocations are related to mechanical impingement or to a biological mechanism that decreases the stability provided by the capsule (eg, inflammation secondary to osteolysis). It is also unknown if alumina-on-alumina bearing couples decrease the risk of late dislocation as a result of the absence of wear and osteolysis. We asked (1) whether the cumulative number of dislocations differed with alumina-on-alumina (AL/AL) or alumina-on-polyethylene bearings (AL/PE); (2) whether patient factors (age, sex, and diseases) affect risk of late dislocation; (3) whether mechanical factors (component malposition, penetration resulting from creep and wear) or (4) biologic hip factors at revision (thickness of the capsule, volume of joint fluid removed at surgery, histology) differed with the two bearing couples. One hundred twenty-six patients (252 hips) with bilateral THA (one AL/AL and the contralateral AL/PE) received the same cemented implants except for the cup PE cup or an AL cup. The cumulative risk of dislocation (first-time and recurrent dislocation) was calculated at a minimum of 27 years. We measured cup position, creep and wear, and capsular thickness in the hips that had revision. AL/PE and AL/AL hips differed by the cumulative number of dislocation (31 with AL/PE versus four with AL/AL) and by the number of late dislocations (none with AL/AL, 28 with AL/PE). Cause of osteonecrosis, age, and sex affected the number of dislocations. The frequency of component malposition did not differ between the two bearing couples. The risk of late dislocation appeared less in AL/AL hips with increased capsular thickness (mean, 4.5 mm; range, 3-7 mm) compared with the thinnest (mean, 1.2 mm; range, 0.2-2 mm) capsule of AL/PE hips. AL/AL bearing couples decreased the cumulative risk of dislocation as compared with AL/PE bearing couples.

  3. Mechanics of hip dysplasia reductions in infants using the Pavlik harness: a physics-based computational model.

    PubMed

    Ardila, Orlando J; Divo, Eduardo A; Moslehy, Faissal A; Rab, George T; Kassab, Alain J; Price, Charles T

    2013-05-31

    Biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of Developmental Dysplasia of the Hip (DDH) were studied using a three-dimensional computer model simulating hip reduction dynamics in (1) subluxated and (2) fully dislocated hip joints. Five hip adductor muscles were identified as key mediators of DDH prognosis, and the non-dimensional force contribution of each in the direction necessary to achieve concentric hip reductions was determined. Results point to the adductor muscles as mediators of subluxated hip reductions, as their mechanical action is a function of the degree of hip dislocation. For subluxated hips in abduction and flexion, the Pectineus, Adductor Brevis, Adductor Longus, and proximal Adductor Magnus contribute positively to reduction, while the rest of the Adductor Magnus contributes negatively. In full dislocations all muscles contribute detrimentally to reduction, elucidating the need for traction to reduce Graf IV type dislocations. Reduction of dysplastic hips was found to occur in two distinct phases: (a) release phase and (b) reduction phase. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Revision of Failed Hip Resurfacing and Large Metal-on-Metal Total Hip Arthroplasty Using Dual-Mobility Components.

    PubMed

    Snir, Nimrod; Park, Brian K; Garofolo, Garret; Marwin, Scott E

    2015-06-01

    Revision of metal-on-metal (MoM) total hip arthroplasty (THA) or hip resurfacing is associated with high complication rates. The authors propose dual-mobility components as a surgical option and present short- to mid-term results of MoM hips revised with dual-mobility components. Eighteen consecutive hips that underwent revision of MoM THA or hip resurfacing using dual-mobility components were identified. At final follow-up (mean, 17.5 months), the visual analog scale, modified Harris Hip Score, and SF-12 scores had all improved (P<.05, P<.01, and P<.05, respectively). There were no dislocations or other complications. Revision of failed MoM THA or hip resurfacing using a dual-mobility device is an effective strategy. Copyright 2015, SLACK Incorporated.

  5. Dislocation climb models from atomistic scheme to dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Niu, Xiaohua; Luo, Tao; Lu, Jianfeng; Xiang, Yang

    2017-02-01

    We develop a mesoscopic dislocation dynamics model for vacancy-assisted dislocation climb by upscalings from a stochastic model on the atomistic scale. Our models incorporate microscopic mechanisms of (i) bulk diffusion of vacancies, (ii) vacancy exchange dynamics between bulk and dislocation core, (iii) vacancy pipe diffusion along the dislocation core, and (iv) vacancy attachment-detachment kinetics at jogs leading to the motion of jogs. Our mesoscopic model consists of the vacancy bulk diffusion equation and a dislocation climb velocity formula. The effects of these microscopic mechanisms are incorporated by a Robin boundary condition near the dislocations for the bulk diffusion equation and a new contribution in the dislocation climb velocity due to vacancy pipe diffusion driven by the stress variation along the dislocation. Our climb formulation is able to quantitatively describe the translation of prismatic loops at low temperatures when the bulk diffusion is negligible. Using this new formulation, we derive analytical formulas for the climb velocity of a straight edge dislocation and a prismatic circular loop. Our dislocation climb formulation can be implemented in dislocation dynamics simulations to incorporate all the above four microscopic mechanisms of dislocation climb.

  6. Acetabular augmentation for the treatment of unstable total hip arthroplasties.

    PubMed Central

    Nicholl, J. E.; Koka, S. R.; Bintcliffe, I. W.; Addison, A. K.

    1999-01-01

    Twenty-eight unstable total hip arthroplasties were treated with an acetabular augmentation wedge. Of the hips, 23 have had no further dislocations at a mean follow-up of 26 months. Five patients continued to dislocate and have needed further surgery. To our knowledge this is the largest reported series of acetabular augmentation with as good results as those of the most successful reported series of this technique, and a success rate comparable to other methods of treating recurrent dislocation. Careful patient selection, and using a thin augmentation wedge to avoid impingement, are important to the success of a technique which is a useful option in the management of recurrent dislocation. Images Figure 1 PMID:10364973

  7. Supersonic Dislocation Bursts in Silicon

    DOE PAGES

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; ...

    2016-06-06

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolutionmore » we successfully predict a dislocation density of 1.5 x 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.« less

  8. Supersonic Dislocation Bursts in Silicon

    SciTech Connect

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-06-06

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 x 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.

  9. Supersonic Dislocation Bursts in Silicon

    NASA Astrophysics Data System (ADS)

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-06-01

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 × 1012 cm-2 within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.

  10. Choices and compromises in the use of small head sizes in total hip arthroplasty.

    PubMed

    Callaghan, John J; Brown, Thomas D; Pedersen, Douglas R; Johnston, Richard C

    2002-12-01

    Observation cohort studies, a sliding-distance-coupled finite element model, and an expanded finite element model that simulates dislocation were used to evaluate the benefits and compromises associated with the use of smaller femoral heads in the total hip arthroplasty construct. Wear studies of total hip arthroplasty cohorts showed less polyethylene wear and less deleterious effects of third body debris when smaller femoral head sizes were used. The sliding-distance-coupled finite element model findings were corroborated by these clinical wear studies. The dislocation model predicted the increased propensity for dislocation when smaller modular head femoral components were used in the cohort studies. Impingement is not the only contributor to frank dislocation. The dislocation model explicitly defined the range of motion changes from impingement to dislocation, and the resisting moment changes between construct designs.

  11. Hip arthroscopy

    MedlinePlus

    Johnson D, Weiss WM. Basic arthroscopic principles. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ... 11. Sanchez VMI, Meza AO. Hip arthroscopy. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ...

  12. Quantitative calculation of dislocation mobility

    SciTech Connect

    Swaminarayan, S.; Preston, D.L.

    1999-07-01

    The authors present a new method to calculate the response of dislocations to applied stress. This new method, called the dislocation treadmill, can be used to study the effect of vacancies, interstitials, stresses, strain rate, temperature, etc., on the steady state velocity of the dislocation. The authors demonstrate the use of the method by calculating the response of a dislocation to a constant applied shear stress.

  13. Behavior of dislocations in silicon

    SciTech Connect

    Sumino, Koji

    1995-08-01

    A review is given of dynamic behavior of dislocations in silicon on the basis of works of the author`s group. Topics taken up are generation, motion and multiplication of dislocations as affected by oxygen impurities and immobilization of dislocations due to impurity reaction.

  14. Dislocated Worker Project.

    ERIC Educational Resources Information Center

    1988

    Due to the severe economic decline in the automobile manufacturing industry in southeastern Michigan, a Dislocated Workers Program has been developed through the partnership of the Flint Area Chamber of Commerce, three community colleges, the National Center for Research in Vocational Education, the Michigan State Department of Education, the…

  15. Dislocated Worker Project.

    ERIC Educational Resources Information Center

    1988

    Due to the severe economic decline in the automobile manufacturing industry in southeastern Michigan, a Dislocated Workers Program has been developed through the partnership of the Flint Area Chamber of Commerce, three community colleges, the National Center for Research in Vocational Education, the Michigan State Department of Education, the…

  16. Elbow fractures and dislocations.

    PubMed

    Little, Kevin J

    2014-07-01

    Elbow fractures are common in pediatric patients. Most injuries to the pediatric elbow are stable and require simple immobilization; however, more severe fractures can occur, often requiring operative stabilization and/or close monitoring. This article highlights the common fractures and dislocations about the pediatric elbow and discusses the history, evaluation, and treatment options for specific injuries.

  17. [Resurfacing arthroplasty of the hip].

    PubMed

    Knecht, A; Witzleb, W-C; Günther, K-P

    2005-01-01

    Currently, an increase in resurfacing arthroplasty in the treatment of hip osteoarthritis--especially in young adults--can be observed. New bearing technologies (mainly metal-on-metal surfaces) show better tribologic results than historical designs (e.g. the Wagner cup). At present, it is unclear whether these modifications and a definitively low dislocation rate--due to the large head diameter--can be supported by further good clinical results. The quantity as well as the quality of the available investigations prevents a definite opinion at the moment. Appropriate clinical studies with documented radiographic follow-up are necessary to compare the outcome of these new implants with standard techniques.

  18. Hip reconstruction surgery is successful in restoring joint congruity in patients with cerebral palsy: long-term outcome.

    PubMed

    Braatz, Frank; Eidemüller, Annette; Klotz, Matthias C; Beckmann, Nicholas A; Wolf, Sebastian I; Dreher, Thomas

    2014-11-01

    Neurogenic hip dislocation is frequently observed in patients with cerebral palsy (CP). If the hip is not centred but not dislocated, the hip joint can be recentered with minor operative effort. Reconstructive procedures are indicated if the femoral head is subluxated or dislocated. There are no data as to when destruction of the femoral head requires a salvage procedure or whether hip reconstruction surgery is successful in restoring joint congruity in patients with CP. Our aim was to investigate femoral head plasticity after hip reconstruction surgery in a long-term outcome study. We studied a large cohort of patients with CP and high hip dislocation (Tönnis grade IV) before surgery. Sixty-eight patients were assessed, of whom 23 presented with bilateral high hip dislocation, and 91 complex hip reconstructions were conducted. Standardised radiographic examination was performed before and directly after surgery and at the long-term follow-up examination. Pain was the most frequent reason for complex hip-joint reconstruction (49 patients, 72%). An impressive improvement in pain was demonstrated postoperatively. Forty-five hip joints presented aspheric incongruity postoperatively, which improved on average 7.7 years after surgery and 59 hip joints showed congruency. Only 15% of patients experienced pain at the time of final follow-up, and that was of low intensity. Early conservative treatment for hip dislocation is helpful, and operative reconstruction should also be scheduled early. Continued surveillance is necessary, and Reimers index is useful for monitoring the development of hip centering. In case of hip pain and femoral head deformity, our long-term study indicates that hip reconstruction surgery as a part of multilevel surgery improves pain and function in patients with CP and Tönnis IV hip dislocation, even if the hip joint is incongruent after operation. This incongruity improves over the long-term. If possible, a reconstruction procedure should be

  19. Hip Microfracture

    PubMed Central

    McGill, Kevin C.; Bush-Joseph, Charles A.; Nho, Shane J.

    2010-01-01

    Microfracture is a marrow-stimulating technique used in the hip to treat cartilage defects associated with femoro-acetabular impingement, instability, or traumatic hip injury. These defects have a low probability of healing spontaneously and therefore often require surgical intervention. Originally adapted from the knee, microfracture is part of a spectrum of cartilage repair options that include palliative procedures such as debridement and lavage, reparative procedures such as marrow-stimulating techniques (abrasion arthroplasty and microfracture), and restorative procedures such as autologous chondrocyte implantation and osteochondral allograft/autografts. The basic indications for microfracture of the hip include focal and contained lesions typically less than 4 cm in diameter, full-thickness (Outerbridge grade IV) defects in weightbearing areas, unstable lesions with intact subchondral bone, and focal lesions without evidence of surrounding chondromalacia. Although not extensively studied in the hip, there are some small clinical series with promising early outcomes. Although the widespread use of microfracture in the hip is hindered by difficulties in identifying lesions on preoperative imaging and instrumentation to circumvent the femoral head, this technique continues to gain acceptance as an initial treatment for small, focal cartilage defects. PMID:26069544

  20. Tailoring Superconductivity with Quantum Dislocations.

    PubMed

    Li, Mingda; Song, Qichen; Liu, Te-Huan; Meroueh, Laureen; Mahan, Gerald D; Dresselhaus, Mildred S; Chen, Gang

    2017-08-09

    Despite the established knowledge that crystal dislocations can affect a material's superconducting properties, the exact mechanism of the electron-dislocation interaction in a dislocated superconductor has long been missing. Being a type of defect, dislocations are expected to decrease a material's superconducting transition temperature (Tc) by breaking the coherence. Yet experimentally, even in isotropic type I superconductors, dislocations can either decrease, increase, or have little influence on Tc. These experimental findings have yet to be understood. Although the anisotropic pairing in dirty superconductors has explained impurity-induced Tc reduction, no quantitative agreement has been reached in the case a dislocation given its complexity. In this study, by generalizing the one-dimensional quantized dislocation field to three dimensions, we reveal that there are indeed two distinct types of electron-dislocation interactions. Besides the usual electron-dislocation potential scattering, there is another interaction driving an effective attraction between electrons that is caused by dislons, which are quantized modes of a dislocation. The role of dislocations to superconductivity is thus clarified as the competition between the classical and quantum effects, showing excellent agreement with existing experimental data. In particular, the existence of both classical and quantum effects provides a plausible explanation for the illusive origin of dislocation-induced superconductivity in semiconducting PbS/PbTe superlattice nanostructures. A quantitative criterion has been derived, in which a dislocated superconductor with low elastic moduli and small electron effective mass and in a confined environment is inclined to enhance Tc. This provides a new pathway for engineering a material's superconducting properties by using dislocations as an additional degree of freedom.

  1. Infection in periprosthetic hip fractures.

    PubMed

    Cabral, Rui

    2012-01-01

    Fracture around the acetabulum and femur in total hip arthroplasty is a possible complication, sometimes with difficult surgical solution, namely when a sepsis is present. Periprosthetic hip fractures were classified according to a modified Vancouver classification. We treated 112 patients (67 men and 45 women) with periprosthetic hip fractures: 105 femoral fractures (94%) and seven acetabular fractures (6%). Mean follow-up was 10.6 years. For Type A (seven cases - 7%), B1 (10 cases - 10%) or C (13 cases - 12%) fractures around well fixed femoral stems we only fixed the fractures. For Type B2 (17 cases - 16%), B3 (46 cases - 44%) and D (12 cases - 11%, with associated fractures, not contemplated in the Vancouver classification) we used an uncemented long femoral stem, fixation with metallic cables and cancellous bone allografts to fill the femoral bone loss. We observed a deep infection in three patients (2.7%), three early hip dislocations treated by closed reductions, two cases with asymptomatic trochanteric non-union and one femoral refracture. In the three infection cases we performed two-stage revision with cementless hip prosthesis, using an antibiotic-loaded cement hip spacer (three to eight months), a six weeks period of parenteral antibiotics and we performed articular aspiration before revision surgery. Until now, we did not observe any re-infection. It is very important to make an early diagnosis, isolate micro-organisms and ensure their antibiotic susceptibility. The surgery solution depends on the well fixed implants and periprosthetic osteolysis and articular instability.

  2. Hip and spine surgery is of questionable value in spina bifida: an evidence-based review.

    PubMed

    Wright, James G

    2011-05-01

    Although many children with spina bifida and associated scoliosis or dislocated hips undergo spine or hip surgery, the benefits are uncertain. The purpose was to perform an evidence-based review on the benefits and risks of surgery for dislocated hips and scoliosis in spina bifida. I performed a Medline(®) and Embase(®) search from 1950 to 2009 for Level I to Level III studies investigating the benefits and risks of surgery for scoliosis and hip dislocation in patients with spina bifida. When available, I extracted types of surgery, complication rates, functional outcomes of seating, walking, and overall physical function. All treatment recommendations received a Grade of Recommendation: Grade A (consistent Level I studies); Grade B (consistent Level II and III studies); Grade C (consistent level IV and V studies); or Grade I (insufficient or contradictory studies). Combined anterior and posterior surgery had lower rates of nonunion for scoliosis. Although there may be some benefit in seating, overall physical function measured in a different and nonstandardized fashion was not much changed and major complication rates, including nonunion and infections for scoliosis surgery, exceed 50% in several studies. For dislocated hips, the impact on walking ability appears related to contracture (not dislocation). Surgery for hip dislocation did not improve walking ability. The literature provides no guidance on the best treatment for unilateral dislocation. The benefits of scoliosis surgery are uncertain (Grade I). Spine surgery, if performed, should be anterior and posterior (Grade B). An all-pedicle approach for scoliosis surgery may be effective (Level I). Hip reduction surgery did not improve walking (Grade B) but may be appropriate in low-level unilateral dislocation (Level I).

  3. Neglected isolated scaphoid dislocation

    PubMed Central

    Baek, Jong-Ryoon; Cho, Seung Hyun; Lee, Yong Seuk; Roh, Young Hak

    2016-01-01

    The authors present a case of isolated scaphoid dislocation in a 40-year-old male that was undiagnosed for 2 months. The patient was treated by open reduction, Kirschner wire fixation, interosseous ligament repair using a suture anchor and Blatt's dorsal capsulodesis. At 6 years followup, his radiographs of wrist showed a normal carpal alignment with a scapholunate gap of 3 mm and no evidence of avascular necrosis (AVN) of the scaphoid. PMID:27904228

  4. Constrained components for the unstable hip following total hip arthroplasty: a literature review.

    PubMed

    Williams, J T; Ragland, P S; Clarke, S

    2007-06-01

    Patients with chronic instability or late dislocation following total hip arthroplasty often require operative management. Unfortunately, there is an increased risk of recurrent dislocation following revision in these patients. Over the past decade the use of constrained devices for patients with chronic instability has gained increased interest; however, there is a paucity of studies available in the literature regarding the use of these devices. The purpose of this study was to analyze the available literature over the past 15 years, focusing on larger, long-term studies, to obtain recommendations from the respective articles for indications and contraindications for the use of constrained devices. Our review of eight reports included 1,199 hips in 1,148 patients with a total mean follow-up of 51 months (range, 24 to 124 months). The mean rate of dislocation following revision with a constrained liner was 10% and the mean re-operation rate for reasons other than dislocation was 4%. We concluded that constrained liners are an option for patients who have failed management of instability with other implants, those with instability of unclear etiology, those with cognitive problems who are unable to follow dislocation precautions, those with deficient abductors, and elderly or low-demand individuals with well-positioned implants requiring revision.

  5. Solute atmospheres at dislocations

    DOE PAGES

    Hirth, John P.; Barnett, David M.; Hoagland, Richard G.

    2017-06-01

    In this study, a two-dimensional plane strain elastic solution is determined for the Cottrell solute atmosphere around an edge dislocation in an infinitely long cylinder of finite radius (the matrix), in which rows of solutes are represented by cylindrical rods with in-plane hydrostatic misfit (axial misfit is also considered). The periphery of the matrix is traction-free, thus introducing an image solute field which generates a solute-solute interaction energy that has not been considered previously. The relevant energy for the field of any distribution of solutes coexistent with a single edge dislocation along the (matrix) cylinder axis is determined, and coherencymore » effects are discussed and studied. Monte Carlo simulations accounting for all pertinent interactions over a range of temperatures are found to yield solute distributions different from classical results, namely, (1) Fermi-Dirac condensations at low temperatures at the free surface, (2) the majority of the atmosphere lying within an unexpectedly large non-linear interaction region near the dislocation core, and (3) temperature-dependent asymmetrical solute arrangements that promote bending. The solute distributions at intermediate temperatures show a 1/r dependence in agreement with previous linearized approximations. With a standard state of solute corresponding to a mean concentration, c0, the relevant interaction energy expression presented in this work is valid when extended to large concentrations for which Henry's Law and Vegard's Law do not apply.« less

  6. A modified S-ROM stem in primary total hip arthroplasty for developmental dysplasia of the hip.

    PubMed

    Tamegai, Hideaki; Otani, Takuya; Fujii, Hideki; Kawaguchi, Yasuhiko; Hayama, Tetsuo; Marumo, Keishi

    2013-12-01

    This study examined the clinical outcome of 220 hips in 196 Asian patients who underwent primary total hip arthroplasty (THA) for treatment of developmental dysplasia of the hip (DDH) using a modified S-ROM modular (S-ROM-A) stem designed for Asians, after 2-5 years (mean, 3.3 years) of follow-up. The stem was placed so that the anteversion angle of the neck was decreased against the sleeve in 56% of the hips and increased in 18% of the hips. Bone ingrown fixation was achieved in 99.5% of the hips on X-ray at final follow-up. There were 2 (0.9%) dislocations postoperatively. In primary THA for treatment of DDH accompanied by femoral rotational deformity, the freely-rotatable modular stem provided favorable short-term outcomes by affording both morphological and functional advantages.

  7. Surgical Management of Hip Problems in Myelomeningocele: A Review Article

    PubMed Central

    Baghdadi, Taghi; abdi, Reza; Bashi, Ramin Zargar; Aslani, Hossein

    2016-01-01

    Background: Children with myelomeningocele (MMC) develop a wide variety of hip deformities such as muscle imbalance, contracture, subluxation, and dislocation. Various methods and indications have been introduced for treatment of muscle imbalances and other hip problems in patients with MMC but there is no study or meta-analysis to compare the results and complications. This review aims to find the most acceptable approach to hip problems in patients with MMC. Methods: MEDLINE was searched up to April 2015. All study designs that reported on the outcomes of hip problems in MMC were included. From 270 screened citations, 55 were strictly focused on hip problem in MMC were selected and reviewed. Results: Complex osseous and soft tissue reconstructive procedures to correct hip dysplasia and muscle balancing around the hip are rarely indicated for MMC patients without good quadriceps power. Conclusion: Over the years a consensus on the best algorithm for treatment of hip dislocation in myelomeningocele has been missing, however, muscular balancing with/out osseous procedure seems a reasonable approach especially in unilateral mid-lumbar MMC. PMID:27517062

  8. Lessons learned from study of congenital hip disease in adults

    PubMed Central

    Hartofilakidis, George; Lampropoulou-Adamidou, Kalliopi

    2016-01-01

    Orthopaedic surgeons specialising in adult hip reconstruction surgery often face the problem of osteoarthritis secondary to congenital hip disease (CHD). To achieve better communication among physicians, better treatment planning and evaluation of the results of various treatment options, an agreed terminology is needed to describe the entire pathology. Furthermore, a generally accepted classification of the deformities is necessary. Herein, the authors propose the use of the term “congenital hip disease” and its classification as dysplasia, low dislocation and high dislocation. Knowledge of the CHD natural history facilitates comprehension of the potential development and progression of the disease, which differs among the aforementioned types. This can lead to better understanding of the anatomical abnormalities found in the different CHD types and thus facilitate preoperative planning and choice of the most appropriate management for adult patients. The basic principles for improved results of total hip replacement in patients with CHD, especially those with low and high dislocation, are: Wide exposure, restoration of the normal centre of rotation and the use of special techniques and implants for the reconstruction of the acetabulum and femur. Application of these principles during total hip replacement in young female patients born with severe deformities of the hip joint has led to radical improvement of their quality of life. PMID:28032030

  9. Revision hip arthroplasty in patients with a previous total hip replacement for osteonecrosis of the femoral head.

    PubMed

    Park, Youn-Soo; Moon, Young-Wan; Lee, Keun-Ho; Lim, Seung-Jae

    2014-12-01

    Patients with osteonecrosis of the femoral head are typically relatively young and active and often require high rates of revision after primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have rarely been reported in the literature. The authors conducted a retrospective review of 72 patients (75 hips) who underwent revision hip arthroplasty with a primary diagnosis of osteonecrosis of the femoral head. Mean age at index revision was 53.3 years (range, 34-76). Components of acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 3 hips. Components of femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. Mean duration of follow-up was 7 years (range, 3-17). Mean Harris Hip Score improved from 49 points preoperatively to 90 points postoperatively. At final follow-up, 11 hips (14.7%) required reoperation because of aseptic loosening (6 hips), infection (2 hips), recurrent dislocation (1 hip), periprosthetic fracture (1 hip), and ceramic fracture (1 hip). Kaplan-Meier survivor-ship with an endpoint of re-revision for any reason was 81% and for mechanical failure was 87.5% for the cup and 100% for the stem at 10 years. Unlike the previous report, the authors' study showed a lower failure rate of the femoral stem after revision hip arthroplasty using modern cementless femoral components in patients with osteonecrosis of the femoral head. Aseptic cup loosening or osteolysis is the most common mechanism of failure at medium-term follow-up. Copyright 2014, SLACK Incorporated.

  10. Open and Arthroscopic with Mini-Open Surgical Hip Approaches for Treatment of Pigmented Villonodular Synovitis and Concomitant Hip Pathology

    PubMed Central

    2017-01-01

    Background. Pigmented villonodular synovitis (PVNS) is a rare benign tumor affecting large joints and prompts excision to prevent local destruction of the joint. The purpose of this case report is to describe two differing surgical approaches for management of PVNS of the hip in patients requiring concomitant treatment for additional hip pathology. Methods. This report discusses the presentation, clinical and radiographic findings, and operative management of two contrasting cases of PVNS of the hip. Case 1 describes a 31-year-old female with localized PVNS in addition to a labral tear treated with arthroscopic labral repair followed by tumor excision via a mini-open incision. Case 2 describes a 29-year-old male with more diffuse PVNS in addition to a cam deformity managed with open surgical dislocation of the hip, tumor excision, and restoration of the femoral head/neck junction. Results. This report demonstrates two cases of successful excision of PVNS of the hip in addition to addressing concomitant hip pathology in both cases. Conclusions. Open surgical dislocation of the hip or arthroscopic surgery with a mini-open incision may be used in appropriately selected patients to successfully excise PVNS lesions in addition to addressing concomitant hip pathology. PMID:28326214

  11. Open and Arthroscopic with Mini-Open Surgical Hip Approaches for Treatment of Pigmented Villonodular Synovitis and Concomitant Hip Pathology.

    PubMed

    Ellsworth, Bridget; Kamath, Atul F

    2017-01-01

    Background. Pigmented villonodular synovitis (PVNS) is a rare benign tumor affecting large joints and prompts excision to prevent local destruction of the joint. The purpose of this case report is to describe two differing surgical approaches for management of PVNS of the hip in patients requiring concomitant treatment for additional hip pathology. Methods. This report discusses the presentation, clinical and radiographic findings, and operative management of two contrasting cases of PVNS of the hip. Case 1 describes a 31-year-old female with localized PVNS in addition to a labral tear treated with arthroscopic labral repair followed by tumor excision via a mini-open incision. Case 2 describes a 29-year-old male with more diffuse PVNS in addition to a cam deformity managed with open surgical dislocation of the hip, tumor excision, and restoration of the femoral head/neck junction. Results. This report demonstrates two cases of successful excision of PVNS of the hip in addition to addressing concomitant hip pathology in both cases. Conclusions. Open surgical dislocation of the hip or arthroscopic surgery with a mini-open incision may be used in appropriately selected patients to successfully excise PVNS lesions in addition to addressing concomitant hip pathology.

  12. A comparison of total hip resurfacing and total hip arthroplasty - patients and outcomes.

    PubMed

    Fowble, Vincent A; dela Rosa, Mylene A; Schmalzried, Thomas P

    2009-01-01

    A comparison of pertinent preoperative and postoperative data relative to total hip resurfacing versus total hip arthroplasty (THA) would assist in evaluating current perceptions in outcome. We compared 50 consecutive metal-metal resurfacing replacements in 50 patients with 44 consecutive conventional total hip arthroplasties in 35 patients, who were implanted during the same time period, by the same surgeon, and followed prospectively for 2 to 4 years. The patients undergoing hip resurfacing were 62% male, 9 years younger, and 3.2 inches taller, with a lower mean body mass index and American Society of Anesthesiologists (ASA) grade than patients undergoing total hip arthroplasty. Preoperatively, patients undergoing resurfacing had a lower Harris hip score (46 vs 52 points), more pain, higher UCLA (University of California at Los Angeles) activity scores (4.2 vs 3.6), and better range of motion. Surgical time for resurfacing was 18% longer, but there was less total blood loss and fewer transfusions. Postoperatively, there was no difference in Harris hip score (97 vs 96). Patients undergoing resurfacing had higher function, Short Form-12 physical activity scores, and UCLA activity scores, but also a higher incidence of slight or mild pain. There were no differences in postoperative range of motion or dislocation (one each). The preoperative characteristics and general health status of the average patient undergoing resurfacing are more favorable than that of the average patient undergoing conventional total hip arthroplasty. Caution should be applied in attributing differences in outcomes directly to the arthroplasty technology.

  13. Dislocation Diffusion in Metallic Materials

    DTIC Science & Technology

    2011-09-08

    DATES COVERED (From - To) April 1,2007-March 31, 2010 4. TITLE AND SUBTITLE Dislocation Diffusion in Metallic Materials 5a. CONTRACT NUMBER...SUPPLEMENTARY NOTES 14. ABSTRACT The goals of this project were: (1) perform a fundamental study of atomic diffusion along dislocation cores in metals and...alloys, (2) develop new methods for the calculation of dislocation diffusion coefficients as functions of temperature and chemical composition and (3

  14. [Congenital knee dislocation: case report].

    PubMed

    Arvinius, C; Luque, R; Díaz-Ceacero, C; Marco, F

    2016-01-01

    Congenital knee dislocation is an infrequent condition with unknown etiology. In some cases it occurs as an isolated condition, while in others it coexists with associated conditions or syndromes. The treatment of congenital knee dislocation is driven by the severity and flexibility of the deformity. The literature includes from serial casting or the Pavlik harness to quadriceps tendon plasty or femoral osteotomies. We report herein the case of a congenital dislocation treated with serial casting with a good outcome.

  15. Design rules for dislocation filters

    SciTech Connect

    Ward, T.; Sánchez, A. M.; Beanland, R.; Tang, M.; Wu, J.; Liu, H.; Dunstan, D. J.

    2014-08-14

    The efficacy of strained layer threading dislocation filter structures in single crystal epitaxial layers is evaluated using numerical modeling for (001) face-centred cubic materials, such as GaAs or Si{sub 1−x}Ge{sub x}, and (0001) hexagonal materials such as GaN. We find that threading dislocation densities decay exponentially as a function of the strain relieved, irrespective of the fraction of threading dislocations that are mobile. Reactions between threading dislocations tend to produce a population that is a balanced mixture of mobile and sessile in (001) cubic materials. In contrast, mobile threading dislocations tend to be lost very rapidly in (0001) GaN, often with little or no reduction in the immobile dislocation density. The capture radius for threading dislocation interactions is estimated to be approximately 40 nm using cross section transmission electron microscopy of dislocation filtering structures in GaAs monolithically grown on Si. We find that the minimum threading dislocation density that can be obtained in any given structure is likely to be limited by kinetic effects to approximately 10{sup 4}–10{sup 5 }cm{sup −2}.

  16. Martensitic phase transition involving dislocations

    NASA Astrophysics Data System (ADS)

    Le, K. C.; Günther, C.

    2015-06-01

    A model of solid-solid phase transition involving dislocations in crystals is proposed within the nonlinear continuum dislocation theory (CDT). The co-existence of phases having piecewise constant plastic slip in laminates is possible for the two-well free energy density. The jumps of the plastic slip across the phase interfaces determine the surface dislocation densities at those incoherent boundaries. The number of phase interfaces should be determined by comparing the energy of dislocation arrays and the relaxed energy minimized among uniform plastic slips.

  17. [Surgical management of hip instabilities in children with spina bifida].

    PubMed

    Erol, Bülent; Bezer, Murat; Küçükdurmaz, Fatih; Güven, Osman

    2005-01-01

    We evaluated the results of surgical management of hip instability in children with spina bifida (SB). Twenty-eight hips of 26 patients (16 girls, 10 boys; mean age 4.5 years; range 3 to 6 years) were surgically managed for hip instability (subluxation/dislocation) associated with SB. Twenty-four patients (2 bilateral dislocations) had low-level lesions (L4-sacral) and a potential to walk, of which 16 patients presented with unilateral dislocation with functional problems including significant (>2 cm) limb-length discrepancy and scoliosis. Two patients had high-level lesions (thoracic-L3) associated with unilateral dislocations and were unable to walk. Those with a high-level lesion and some patients (9/26 hips) with a low-level lesion also had hip flexion contractures. Treatment included open reduction, pelvic osteotomy, proximal femoral osteotomy when necessary, and a spica cast. The patients were clinically and radiographically monitored for a mean of 38 months (range 30 to 48 months). Of 16 patients with functional problems, 14 patients had improvement in their gait patterns, while limb-length discrepancy and scoliosis persisted in two. The remaining 10 patients maintained their preoperative functional statuses. The mean range of motion of the hips decreased postoperatively; however, none of them developed joint stiffness. Early postoperative complications included superficial wound infections in three patients, and distal femoral diaphyseal fractures in two patients. Three patients required removal of the implants in the sixth month due to subcutaneous prominence thereof. Late radiographs of three patients showed recurrent subluxations, which did not require any intervention. Although surgical treatment of hip problems associated with high-level lesions may be unrewarding in children with SB, those associated with low-level lesions can be successfully managed with proper surgical indications.

  18. Sonographic Assessment of Hip Swaddling Techniques in Infants With and Without DDH.

    PubMed

    Harcke, Howard T; Karatas, Ali F; Cummings, Susan; Bowen, James R

    2016-01-01

    The purpose of this single-examination pilot study was to confirm the ability to perform hip sonography while swaddled and to ascertain whether the various swaddling techniques influenced hip position and dynamics. Dynamic sonography was used to evaluate 30 infants in both swaddled and unswaddled positions who were being seen in clinic for suspected or documented developmental dysplasia of the hip. A "treatment group" of 16 infants (32 hips) treated in a Pavlik harness and a "nontreatment group" of 14 untreated infants (28 hips) were studied.Criteria for comparing sonographic results between swaddled and unswaddled hip positions included femoral head position, instability, and range-of-motion restriction. Tight swaddling with a blanket was applied in 11 "nontreatment group" cases (20 hips; in 2 cases, only 1 hip studied) and produced limited flexion and abduction. One unstable left hip dislocated when tightly swaddled. Safe swaddling technique in 12 cases (24 hips) showed no limitation of flexion and abduction of the legs and no change in stability by sonography. Commercial swaddling products appeared to mildly restrict leg motion in 14 hips, but there was no change in hip position in the "nontreatment group." However, the commercial swaddling products changed the hip position in 3 Pavlik harness cases. Swaddling techniques that allow a free range of leg motion may not affect hip stability in normal infants or those being treated with Pavlik harness. Swaddling with restricted leg motion increases potential for hip instability. Tight swaddling dislocated 1 unstable hip, and commercial swaddling products judged to apply only mild restriction of leg motion negatively impacted 3 cases being treated for developmental dysplasia of the hip with Pavlik harness. On the basis of this pilot study, we advise caution when swaddling infants, especially with techniques that restrict leg motion. Further study of the long-term effects of swaddling is warranted. Level II.

  19. Achieving stability and lower limb length in total hip arthroplasty.

    PubMed

    Berend, Keith R; Sporer, Scott M; Sierra, Rafael J; Glassman, Andrew H; Morris, Michael J

    2011-01-01

    Total hip arthroplasty is an exceptionally cost-effective and successful surgical procedure. Dislocation, infection, osteolysis, and limb-length inequality are among the most common complications affecting the long-term success of total hip arthroplasty. Instability is a challenging complication to treat. The surgeon frequently must try to achieve a stable hip at the cost of increasing the length of the operated extremity. It is important to understand the factors associated with stability and limb length; the surgical options available; the effect and role of the various surgical approaches; and methods to manage instability, with and without limb-length inequality.

  20. Developmental dysplasia of the hip in neonates: evolution of acetabular dysplasia after hip stabilization by brief Pavlik harness treatment.

    PubMed

    Bin, K; Laville, J-M; Salmeron, F

    2014-06-01

    The recommended treatment duration in neonates with developmental dysplasia of the hip (DDH) varies depending on whether prolonged Pavlik harness therapy is believed to favourably affect the course of the acetabular dysplasia. According to one theory, several months of additional Pavlik harness therapy after achieving hip reduction contributes to correct the acetabular dysplasia. Another theory holds that hip dislocation induces the acetabular dysplasia, which corrects spontaneously once the femoral head is properly seated in the acetabulum. Here, we evaluated this second theory by studying outcomes after early brief Pavlik harness therapy. Acetabular dysplasia associated with neonatal hip instability undergoes self-correction provided stable hip reduction is achieved very early after birth. Therefore, the duration of Pavlik harness therapy can be substantially shortened. We defined hip instability as either reducible hip dislocation or a very easily dislocatable hip with a soft clunk precluding determination of spontaneous hip position as dislocated or reduced. Static and dynamic ultrasound scans were obtained. Patients with ultrasonographic instability (pubo-femoral distance>5mm with less than 50% of coverage) underwent a second physical examination and received treatment. We re-evaluated 42 abnormal hips in 30 patients after a mean follow-up of 6.7 years (range, 5-14 years). Mean age at treatment initiation was 5 days (range, 1-15 days) and mean treatment duration was 34 days (range, 15-75 days). Mean acetabular angle was 20° (range, 12°-30°) and mean Wiberg's lateral centre-edge angle was 30° (range, 22°-35°). Blunting of the lateral angle of the bony roof was noted in 8 hips at last follow-up. In 1 patient whose hip was stable clinically but unstable by ultrasonography at 21 days of age, recurrent dislocation occurred at 5 months of age. The Severin class was 1a in all patients. Despite continuing controversy about whether hip dislocation induces

  1. Hip arthroscopy: current concepts and review of literature

    PubMed Central

    Shetty, Vijay D; Villar, Richard N

    2007-01-01

    Diagnosis and treatment of intra‐articular hip problems in young patients present a challenge to hip surgeons. Previous studies have shown that non‐invasive investigations such as radiography, computed tomography and magnetic resonance imaging provide limited help. Non‐operative treatment is likely to result in persistent symptoms, and surgical options for intra‐articular hip problems involve open arthrotomy of the hip joint, which carries potential risks associated with joint dislocation. Arthroscopy of the hip joint, therefore, seems to be an attractive option. It was once thought that introduction of a straight arthroscope into the ball‐and‐socket hip joint was almost impossible. Hip arthroscopy has seen several advances since then, and the speed at which it developed in recent years directly corresponded to the rate at which the conditions affecting the hip joint were identified. Athletes and other young individuals with hip injuries are increasingly being diagnosed with an ever evolving series of conditions. Many of these conditions were previously unrecognised and thus left untreated, resulting in premature ends to the patients' competitive careers. Hip arthroscopy, as with any procedure, is not without risks. The procedure is not widely available as it requires specialist equipment and takes a long time to learn. Complications are few, occurring in <5% of patients. PMID:17138638

  2. Septic arthritis of the hip - current concepts.

    PubMed

    Rutz, E; Brunner, R

    2009-01-01

    Septic arthritis of the hip is the commonest septic condition during growth, reaching a distinct peak in frequency during infancy. The aetiology is a haematogenous joint infection. Indicative signs are severe pain when moving the joint, septic appearance and a poor general condition of these small and young patients. The diagnosis often can be difficult in infants since septic temperatures are not always present. An ultrasound scan shows the hip joint effusion and the capsular distension. X-ray investigation helps to exclude defective situations. Therapeutic options are: in patients with short history without radiologically visible complications we recommend repeated arthroscopic irrigation and in patients with long history and a radiologically visible defect of the femoral head or dislocation we recommend arthrotomy and open revision or reduction of the hip joint.

  3. Misfit dislocations in epitaxy

    NASA Astrophysics Data System (ADS)

    van der Merwe, Jan H.

    2002-08-01

    This article on epitaxy highlights the following: the definition and some historical milestones; the introduction by Frenkel and Kontorowa (FK) of a truncated Fourier series to model the periodic interaction at crystalline interfaces; the invention by Frank and van der Merwe (FvdM)—using the FK model—of (interfacial) misfit dislocations as an important mechanism in accommodating misfit at epilayer-substrate interfaces; the generalization of the FvdM theory to multilayers; the application of the parabolic model by Jesser and van der Merwe to describe, for growing multilayers and superlattices, the impact of Fourier coefficients in the realization of epitaxial orientations and the stability of modes of misfit accommodation; the involvement of intralayer interaction in the latter—all features that impact on the attainment of perfection in crystallinity of thin films, a property that is so vital in the fabrication of useful uniformly thick epilayers (uniformity being another technological requirement), which also depends on misfit accommodation through the interfacial energy that function strongly in the criterion for growth modes, proposed by Bauer; and the ingenious application of the Volterra model by Matthews and others to describe misfit accommodation by dislocations in growing epilayers.

  4. Dislocation-Based Si-Nanodevices

    NASA Astrophysics Data System (ADS)

    Reiche, Manfred; Kittler, Martin; Buca, Dan; Hähnel, Angelika; Zhao, Qing-Tai; Mantl, Siegfried; Gösele, Ulrich

    2010-04-01

    The realization of defined dislocation networks by hydrophobic wafer bonding allows the electrical characterization of individual dislocations. The present paper investigates the properties of such dislocations in samples containing high dislocations densities down to only six dislocations. The current induced by a single dislocation is determined by extrapolation of the current measured for various dislocation densities. Based on our present and previously reported analyses the electronic properties of individual dislocations can be inferred. The investigations show that dislocations in the channel of metal-oxide-semiconductor field-effect transistors (MOSFETs) result in increasing drain currents even at low drain and gate voltages. Because a maximum increase of the current is obtained if a single dislocation is present in the channel, arrays of MOSFETs each containing only one dislocation could be realized on the nanometer scale. The distance of the dislocations can be well controlled by wafer bonding techniques.

  5. Total hip replacement in dancers.

    PubMed

    Buyls, Inge R A E; Rietveld, A B M Boni; Ourila, Tiia; Emerton, Mark E; Bird, H A

    2013-04-01

    A case report of a professional contemporary dancer who successfully returned to the stage after bilateral total hip replacements (THR) for osteoarthritis is presented, together with her own commentary and a retrospective cohort study of total hip replacements in dancers. In the presented cohort, there were no post-operative dislocations or infections, the original pain had been relieved, rehabilitation was objectively normal and all resumed their dance (teaching) activities. Nevertheless, they were disappointed about the prolonged rehabilitation. Due to their high demands as professional dancers, post-operative expectations were too optimistic in view of the usual quick and favourable results of THR in the older and less physically active, general population. In all dancers with unilateral osteoarthritis, the left hip was involved, which may reflect the tendency to use the left leg as standing leg and be suggestive that strenuous physical activity may lead to osteoarthritis. Better rehabilitation guidelines are needed for dancer patients undergoing THR, especially drawing their attention to realistic post-operative expectations.

  6. Worker Dislocation and Its Consequences.

    ERIC Educational Resources Information Center

    Rosenbaum, Allan; Zirkin, Barbara G.

    A study examined the socioeconomic characteristcs, family and social supportive services, economic and social difficulties, education and training levels, and ways in which dislocated workers in Maryland found reemployment. Data were collected from in-depth personal interviews with 9 dislocated workers, questionnaires administered to 45 unemployed…

  7. [Acetabular morphological analysis in patients with high dislocated DDH using three-dimensional surface reconstruction technique].

    PubMed

    Zengy, Yi; Min, Li; Lai, Ou-jie; Shen, Bin; Yang, Jing; Zhou, Zong-ke; Kang, Peng-de; Pei, Fu-xing

    2015-03-01

    To simulate acetabular morphology and perform acetabular quantitative analysis in high dislocated developmental dysplasia of the hip (DDH) patients using three-dimensional (3D) surface reconstruction technique, in order to understand the acetabular anatomic features and develop operative strategies for acetabular reconstruction. 3D pelvic images were reconstructed by Mimics software from CT data of 13 patients (13 hips) with high developmental DDH and 13 normal persons (26 hips). True acetabular superior-inferior diameter, anterior-posterior diameter, acetabular depth, medial wall thickness, abduction angle and anteversion angle were measured and compared between the two groups of participants. Irregular acetabular shape was found in high dislocated group, showing a triangle with wide upper and narrow lower. The acetabular quantitative analysis revealed (38.29 +/- 2.71) mm superior-inferior diameter, (21.74 +/- 5.33) mm anterior-posterior diameter, (15.50 +/- 2.93) mm acetabular depth, (6.80 +/- 2.97) mm medial wall thickness, (49.29 +/- 7.40) degrees abduction angle and (23.82 +/- 11.21) degrees anteversion angle in high dislocated patients. The superior-inferior diameter, anterior-posterior diameter and acetabular depth of high dislocated patients were significantly smaller than those of the normal contirols (P<0.05). However, the medial wall thickness, abduction angle and anteversion angle of high dislocated patients were significantly bigger than those of the normal controls (P<0.05). 3D reconstruction technique can restore true acetabular morphology and perform quantitative analysis. Compared with normal controls, high dislocated DDH patients have acetabular features: irregular shape, lower opening, higher medial wall and bigger abduction and anteversion angles. Joint arthroplasty surgery in high dislocated DDH patients needs to look at these acetabular features.

  8. Cobalt toxicity after McKee hip arthroplasty.

    PubMed

    Jones, D A; Lucas, H K; O'Driscoll, M; Price, C H; Wibberley, B

    1975-08-01

    The significance of cobalt as a cause of symptoms after McKee hip arthroplasty is discussed. Seven patients are described in whom such arthroplasties. became unsatisfactory after periods varying from nine months to four years. Six of these patients were cobalt-positive but nickel- and chrome-negative on patch testing. Macroscopic and histological necrosis of bone, muscle and joint capsule around the prostheses was found in five patients whose hips were explored. The symptoms were progressive pain, a feeling of instability, and in two cases spontaneous dislocation. Radiological features included acetabular fracture, bone resorption, loosening and dislocation of the prosthesis. Increased cobalt concentrations (determined by atomic absorption spectrophotometry) in the urine of four patients and in a variety of tissues in one patient are presented. Patch testing is recommended in the investigation of patients with troublesome McKee hip arthroplasties

  9. Salmon calcitonin nasal spray treatment for postmenopausal women after hip fracture with total hip arthroplasty.

    PubMed

    Peichl, Peter; Marteau, Robert; Griesmacher, Andrea; Kumpan, Wofgang; Schedl, Rudolf; Prosquil, Eugen; Fasol, Paul; Bröll, Hans

    2005-01-01

    The increasing rate of hip fractures is giving rise to a number of socioeconomic problems for the aging community. In addition to being unable to resume their previous living habits, many patients fail to achieve full functional recovery after the fractures. Total hip arthroplasty (THA) is a successful operation for the majority of patients with all forms of hip fractures. Dislocation and aseptic loosening are the major reasons for revisions. An additional problem post-THA is the rate of heterotopic soft tissue calcification after total hip arthroplasty, resulting in severely impaired function, pain, and a reduced range of hip motion. In an open study, 37 women who had undergone cementless total hip arthroplasty after accidental hip fractures were treated twice daily with 200 IU salmon calcitonin nasal spray for 12 months. Simultaneously, the patients received one bag of 1000 mg calcium plus 880 IU vitamin D daily throughout the treatment period of 1 year. A parallel group of 38 women with a similar clinical status in terms of hip fractures and cementless total hip arthroplasty were treated with only one bag of 1000 mg calcium plus 880 IU vitamin D daily through the treatment period. The results of this 12-month clinical trial show that 200 IU salmon calcitonin nasal spray per day promotes general independence from foreign assistance, mobility, and fear of further falls in postmenopausal elderly women following THA. Treatment with a salmon calcitonin nasal spray reduces bone turnover serum markers, loss of further bone density, and pain. Additionally, calcitonin promoted the repair of hip fractures and, as a coincidence finding, was associated with a significantly reduced rate of refractures as well as periprosthetic ossifications.

  10. Is congenital talipes equinovarus a risk factor for pathological dysplasia of the hip? : a 21-year prospective, longitudinal observational study.

    PubMed

    Paton, R W; Choudry, Q A; Jugdey, R; Hughes, S

    2014-11-01

    There is controversy whether congenital foot abnormalities are true risk factors for pathological dysplasia of the hip. Previous United Kingdom screening guidelines considered congenital talipes equinovarus (CTEV) to be a risk factor for hip dysplasia, but present guidelines do not. We assessed the potential relationship between pathological dysplasia of the hip and fixed idiopathic CTEV. We present a single-centre 21-year prospective longitudinal observational study. All fixed idiopathic CTEV cases were classified (Harrold and Walker Types 1 to 3) and the hips clinically and sonographically assessed. Sonographic Graf Type III, IV and radiological irreducible hip dislocation were considered to be pathological hip dysplasia. Over 21 years there were 139 children with 199 cases of fixed idiopathic CTEV feet. Sonographically, there were 259 normal hips, 18 Graf Type II hips, 1 Graf Type III hip and 0 Graf Type IV hip. There were no cases of radiological or sonographic irreducible hip dislocation. Fixed idiopathic CTEV should not be considered as a significant risk factor for pathological hip dysplasia. This conclusion is in keeping with the current newborn and infant physical examination guidelines in which the only risk factors routinely screened are family history and breech presentation. Our findings suggest CTEV should not be considered a significant risk factor in pathological dysplasia of the hip. ©2014 The British Editorial Society of Bone & Joint Surgery.

  11. An injury risk curve for the hip for use in frontal impact crash testing.

    PubMed

    Rupp, Jonathan D; Flannagan, Carol A C; Kuppa, Shashi M

    2010-02-10

    To facilitate the assessment of hip injury risk in frontal motor-vehicle crashes, an injury risk curve that relates peak force transmitted to the hip to the probability of hip fracture was developed by using survival analysis to fit a lognormal distribution to a recently published dataset of hip fracture forces. This distribution was parameterized to account for the effect of subject stature, which was the only subject characteristic found to significantly affect hip fracture force (X(2)(1)=6.03, p=0.014). The distribution was further parameterized to account for the effects of hip flexion and abduction from a standard driving posture on hip fracture force using relationships between mean hip fracture force and hip flexion/abduction reported in the literature. The resulting parametric distribution was used to define relationships between force applied to the hip and the risk of hip fracture for the statures associated with the small female, midsize male, and large male crash-test dummies, thus allowing these dummies to assess hip fracture/dislocation risk in frontal crashes, provided that such dummies are sufficiently biofidelic. For the midsize male crash test dummy, a 50% risk of hip fracture was associated with a force of 6.00kN. For the small female and large male dummies, a 50% risk of hip fracture was associated with forces of 4.46 and 6.73kN, respectively. Copyright 2009 Elsevier Ltd. All rights reserved.

  12. Hip health at skeletal maturity: a population-based study of young adults with cerebral palsy.

    PubMed

    Wawrzuta, Joanna; Willoughby, Kate L; Molesworth, Charlotte; Ang, Soon Ghee; Shore, Benjamin J; Thomason, Pam; Graham, H Kerr

    2016-12-01

    We studied 'hip health' in a population-based cohort of adolescents and young adults with cerebral palsy to investigate associations between hip morphology, pain, and gross motor function. Ninety-eight young adults (65 males, 33 females) from the birth cohort were identified as having developed hip displacement (migration percentage >30) and were reviewed at a mean age of 18 years 10 months (range 15-24y). Hip morphology was classified using the Melbourne Cerebral Palsy Hip Classification Scale (MCPHCS). Severity and frequency of pain were recorded using Likert scales. Gross motor function was classified by the Gross Motor Function Classification System (GMFCS). Hip pain was reported in 72% of participants. Associations were found between pain scores and both hip morphology and GMFCS. Median pain severity score for MCPHCS grades 1 to 4 was 2 (interquartile range [IQR] 1.0-3.0) compared to 7 (IQR 6.0-8.0) for grades 5 and 6 (severe subluxation or dislocation). Hip surveillance and access to surgery were associated with improved hip morphology and less pain. Poor hip morphology at skeletal maturity was associated with high levels of pain. Limited hip surveillance and access to surgery, rather than GMFCS, was associated with poor hip morphology. The majority of young adults who had access to hip surveillance, and preventive and reconstructive surgery, had satisfactory hip morphology at skeletal maturity and less pain. © 2016 Mac Keith Press.

  13. Common questions about developmental dysplasia of the hip.

    PubMed

    Jackson, Jonathan C; Runge, Melissa M; Nye, Nathaniel S

    2014-12-15

    Developmental dysplasia of the hip is a common musculoskeletal condition in newborns. Infants with developmental dysplasia of the hip, whether treated or untreated, have a higher incidence of early-onset hip osteoarthritis in adulthood. Evidence to support universal screening by physical examination or ultrasonography is limited and often conflicting. The U.S. Preventive Services Task Force found insufficient evidence that screening for developmental dysplasia of the hip prevents adverse outcomes. Physical examination screening is recommended by the American Academy of Pediatrics and the Pediatric Orthopaedic Society of North America. These organizations recommend use of the Ortolani and Barlow maneuvers to screen infants up to three months of age. Several recent studies support starting assessment for limited hip abduction at eight weeks of age, which is the most sensitive test for developmental dysplasia of the hip from this age on. Infants with overtly dislocated or dislocatable hips should be referred to an orthopedist on a priority basis at the time of diagnosis. Infants with equivocal hip examination findings at birth can be reexamined in two weeks. If there is subluxation or dislocation at the follow-up examination, referral should be made at that time. If the examination findings are still equivocal, the infant can undergo ultrasonography of the hips or be reexamined every few weeks through the first six weeks of life. Although equivocal findings commonly resolve spontaneously, infants with persistent equivocal findings of developmental dysplasia of the hip longer than six weeks should be evaluated by an orthopedist. Treatment generally involves flexion-abduction splinting. The benefits of treatment are unclear, and there are risks to treatment, most notably an increased occurrence of avascular necrosis of the femoral head.

  14. Galeazzi fractures and dislocations.

    PubMed

    Giannoulis, Filippos S; Sotereanos, Dean G

    2007-05-01

    In 1934, fractures of the middle and distal third of the radius associated with instability of the distal radial ulnar joint (DRUJ) were described by Galeazzi. This type of lesion is characterized by its unstable nature and the need for open reduction and internal fixation to achieve a satisfactory functional outcome. A high index of suspicion should be maintained by the surgeon, and a thorough examination for instability of the DRUJ must be conducted. The marked instability of this fracture-dislocation complex is further enhanced by the disruption of the triangular fibrocartilage complex, either with or without ulna styloid fracture. Treatment in adults is surgical, and both bone and soft tissue injuries should be addressed.

  15. Dislocation dynamics and core structure

    NASA Astrophysics Data System (ADS)

    Lin, Karin Shu

    2000-10-01

    Understanding the dynamics of dislocations is essential to the accurate prediction of the mechanical properties of materials. In recent years, considerable progress has been made in this area through the development of large computer simulations which seek to model plastic deformation by considering the interactions of many dislocations. However, the many-body nature of the problem, as well as the limitations inherent in the elasticity theory used to describe dislocation interactions, requires that such simulations make certain simplifying assumptions. The work reported here seeks to examine some of the issues relevant to these simulations in two ways. First, the dynamics of a single dislocation are studied through the development and analysis of a mesoscopic, two-dimensional kinetic Monte Carlo simulation of dislocation motion. The stress and temperature dependence of the dislocation velocity is studied, and finite-size effects are discussed. Through a simple analogy to models of crystal growth, it is shown that the simulated dislocations exhibit kinetic roughening with scaling exponents predicted by the Kardar-Parisi-Zhang equation. Second, the structure of dislocation cores is studied at the atomic level in diamond cubic materials. These studies are necessary for understanding dislocation properties at small distances, and can provide accurate parameters for use in larger scale continuum simulations. The first study uses periodic supercells and ab initio techniques to compare two possible reconstructions of the 90° partial dislocation core in diamond. The relative energies are found to depend upon the stress field experienced by a dislocation in the periodic array. By fitting the energies to an isotropic elasticity theory expression for the dislocation core energy, values for the core radius and shear modulus of diamond are extracted and found to agree well with theoretical estimates and experimental observations. A similar analysis using empirical potentials

  16. Impingement in Total Hip Replacement: Mechanisms and Consequences

    PubMed Central

    Brown, Thomas D.; Callaghan, John J.

    2009-01-01

    The occurrence of total hip impingement, whether or not accompanied by frank dislocation, holds substantial untoward clinical consequences, especially as less-forgiving advanced bearing implant designs come into ever more widespread use. Biomechanical aspects of impingement and dislocation have historically received relatively little scientific attention, although that situation is now rapidly changing. The present article reviews contemporary laboratory and clinical research on the impingement/dislocation phenomena, focusing particularly on how implant design variables, surgical implantation factors and patient activity each act individually and in concert to pose impingement and dislocation challenges. In recent years, several powerful new research methodologies have emerged that have greatly expanded the scope for clinical translation of systematic laboratory study. Transferring the findings from such research into yet better implant designs, and even better surgical procedures, offers encouragement that the clinical impact of this troublesome complication can be further reduced. PMID:19956356

  17. Hip flexor strain - aftercare

    MedlinePlus

    ... flexor - aftercare; Hip flexor injury - aftercare; Hip flexor tear - aftercare; Iliopsoas strain - aftercare; Strained iliopsoas muscle - aftercare; Torn iliopsoas muscle - aftercare; Psoas strain - aftercare

  18. [Short- and medium-term effectivenesses of stemless hip arthroplasty for treating hip joint disease in young and middle-aged patients].

    PubMed

    Chen, Qingzhen; Liu, Wuyang; Gao, Hui; Shi, Mingxiang; Lian, Yucai

    2014-09-01

    To summarize the short- and medium-term effectivenesses of stemless hip arthroplasty for treating hip joint disease in young and middle-aged patients. Between June 2005 and December 2010, 25 cases (27 hips) of hip joint disease were treated with stemless hip arthroplasty. There were 17 males (19 hips) and 8 females (8 hips) with an average age of 45.6 years (range, 30-57 years), including 13 left hips, 10 right hips, and 2 bilateral hips. The causes included avascular necrosis of the femoral head (ANFH) secondary to femoral neck fracture in 5 cases (5 hips), ANFH in 15 cases (16 hips), osteoarthritis of the hip joint caused by ankylosing spondylitis in 2 cases (3 hips), osteoarthritis of the hip joint caused by dysplasia of acetabular in 2 cases (2 hips), and rheumatoid arthritis in 1 case (1 hip). The disease duration was 1-17 years (mean, 6.1 years). Before operation, the Harris score was 47.6 ± 14.2. The incision healed by first intention in all patients, and no complications occurred, such as infection, periprosthetic fracture, and deep vein thrombosis of lower extremity. Twenty-five patients (27 hips) were followed up 36-96 months (mean, 51 months). One case (1 hip) had sciatic nerve injury after operation, which was relieved by symptomatic treatment. One case (1 hip) had prosthesis loosening, which was relieved after revision. The survival rate of prosthesis was 96.3% (26/27). At last follow-up, the Harris score was 92.1 ± 3.6, which was significantly better than preoperative score (t = 18.241, P = 0.000). The excellent and good rate was 88.9% (excellent in 19 hips, good in 5 hips, fair in 2 hips, and poor in 1 hip). The X-ray films showed good location of prosthesis, and no evidence of dislocation, bone resorption, osteolysis, and heterotopic ossification. Because of reserving femoral neck, biomechanics conduction and distribute of the proximal femur achieve natural biomechanics state of the human body. The short- and medium-term effectivenesses of

  19. Buckling of dislocation in graphene

    NASA Astrophysics Data System (ADS)

    Yao, Yin; Wang, Shaofeng; Bai, Jianhui; Wang, Rui

    2016-10-01

    The buckling of dislocation in graphene is discussed through the lattice theory of dislocation and elastic theory. The approximate solution of the buckling is obtained based on the inner stress distribution caused by different structure of dislocations and is proved to be suitable by the simulation. The position of the highest buckling is predicted to be at the vertex of the pentagon far away from the heptagon. The buckling is strongly influenced by the internal stress and the distance between the extrusive area and stretching area, as well as the critical stress σc. The SW defect is proved to be unbuckled due to its strong interaction between extrusion and stretching.

  20. Quenched dislocation enhanced supersolid ordering.

    PubMed

    Toner, John

    2008-01-25

    I show using Landau theory that quenched dislocations can facilitate the supersolid to normal solid transition, making it possible for the transition to occur even if it does not in a dislocation-free crystal. I make detailed predictions for the dependence of the supersolid to normal solid transition temperature T_{c}(L), superfluid density rho_{S}(T,L), and specific heat C(T,L) on temperature T and dislocation spacing L, all of which can be tested against experiments. The results should also be applicable to an enormous variety of other systems, including, e.g., ferromagnets.

  1. Management of acute glenohumeral dislocations.

    PubMed

    Sileo, Michael J; Joseph, Samuel; Nelson, Cory O; Nelson, Corey O; Botts, Jonathan D; Penna, James

    2009-06-01

    The glenohumeral joint is the most commonly dislocated joint in the human body. Glenohumeral joint dislocations account for a large number of orthopedic consultations in inpatient and outpatient settings. A thorough workup is required for accurate diagnosis and appropriate treatment of this injury. Complete history and physical examination and radiographic studies are essential, and reduction should always be attempted. In this article, we review the literature for each phase of the workup for glenohumeral dislocation and describe the anatomy, biomechanics, and basic science of the injury. Featured is a detailed synopsis of the more commonly used reduction maneuvers plus their risks and success rates.

  2. Patellar Dislocations and Reduction Procedure.

    PubMed

    Ramponi, Denise

    2016-01-01

    Acute patellar dislocations are a common injury occurring in adolescents involved in sports and dancing activities. This injury usually occurs when the knee is in full extension and sustains a valgus stress on the knee. The medial patellofemoral ligament is the medial restraint that assists in stabilizing the patella from lateral dislocations. The patella usually dislocates laterally and is usually not difficult to reduce after patient evaluation and prereduction radiographs. After postreduction radiographs confirm proper position of the patella postreduction and the absence of fractures, the patient is usually treated conservatively with initial immobilization, orthopedic referral, and physical therapy.

  3. Statistical analysis of dislocations and dislocation boundaries from EBSD data.

    PubMed

    Moussa, C; Bernacki, M; Besnard, R; Bozzolo, N

    2017-08-01

    Electron BackScatter Diffraction (EBSD) is often used for semi-quantitative analysis of dislocations in metals. In general, disorientation is used to assess Geometrically Necessary Dislocations (GNDs) densities. In the present paper, we demonstrate that the use of disorientation can lead to inaccurate results. For example, using the disorientation leads to different GND density in recrystallized grains which cannot be physically justified. The use of disorientation gradients allows accounting for measurement noise and leads to more accurate results. Misorientation gradient is then used to analyze dislocations boundaries following the same principle applied on TEM data before. In previous papers, dislocations boundaries were defined as Geometrically Necessary Boundaries (GNBs) and Incidental Dislocation Boundaries (IDBs). It has been demonstrated in the past, through transmission electron microscopy data, that the probability density distribution of the disorientation of IDBs and GNBs can be described with a linear combination of two Rayleigh functions. Such function can also describe the probability density of disorientation gradient obtained through EBSD data as reported in this paper. This opens the route for determining IDBs and GNBs probability density distribution functions separately from EBSD data, with an increased statistical relevance as compared to TEM data. The method is applied on deformed Tantalum where grains exhibit dislocation boundaries, as observed using electron channeling contrast imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Current Concepts in Hip Preservation Surgery: Part I.

    PubMed

    Adler, Kelly L; Cook, P Christopher; Yen, Yi-Meng; Giordano, Brian D

    2015-01-01

    An evolution in conceptual understanding, coupled with technical innovations, has enabled hip preservation surgeons to address complex pathomorphologies about the hip joint to reduce pain, optimize function, and potentially increase the longevity of the native hip joint. Technical aspects of hip preservation surgeries are diverse and range from isolated arthroscopic or open procedures to hybrid procedures that combine the advantages of arthroscopy with open surgical dislocation, pelvic and/or proximal femoral osteotomy, and biologic treatments for cartilage restoration. PubMed and CINAHL databases were searched to identify relevant scientific and review articles from January 1920 to January 2015 using the search terms hip preservation, labrum, surgical dislocation, femoroacetabular impingement, peri-acetabular osteotomy, and rotational osteotomy. Reference lists of included articles were reviewed to locate additional references of interest. Clinical review. Level 4. Thoughtful individualized surgical procedures are available to optimize the femoroacetabular joint in the presence of hip dysfunction. A comprehensive understanding of the relationship between femoral and pelvic orientation, morphology, and the development of intra-articular abnormalities is necessary to formulate a patient-specific approach to treatment with potential for a successful long-term result. © 2015 The Author(s).

  5. Preventing Leg Length Discrepancy and Instability After Total Hip Arthroplasty.

    PubMed

    Sculco, Peter K; Austin, Matthew S; Lavernia, Carlos J; Rosenberg, Aaron G; Sierra, Rafael J

    2016-01-01

    Restoration of equal leg lengths and dynamic hip stability are essential elements of a successful total hip arthroplasty. A careful clinical examination, a preoperative plan, and appropriate intraoperative techniques are necessary to achieve these goals. Preoperative identification of patients at risk for residual leg length discrepancy allows surgeons to adjust the surgical approach and/or the type of implant and provide better preoperative patient education. The use of larger femoral heads, high-offset stem options, and enhanced soft-tissue repairs have improved impingement-free range of motion as well as dynamic hip stability and have contributed to an overall reduction in dislocation. Methods for accurate leg length restoration and component positioning include anatomic landmarks, intraoperative radiographs, intraoperative calipers, stability testing, and computer-assisted surgery. If recurrent instability occurs after total hip arthroplasty, the underlying cause for dislocation should be identified and treated; this may include the use of semiconstrained dual-mobility or fully constrained liners, depending on abductor function. Surgeons should be aware of the clinical and surgical techniques for achieving leg length equalization and dynamic hip stability in total hip arthroplasty.

  6. Current Concepts in Hip Preservation Surgery

    PubMed Central

    Adler, Kelly L.; Cook, P. Christopher; Geisler, Paul R.; Yen, Yi-Meng; Giordano, Brian D.

    2016-01-01

    Context: Successful treatment of nonarthritic hip pain in young athletic individuals remains a challenge. A growing fund of clinical knowledge has paralleled technical innovations that have enabled hip preservation surgeons to address a multitude of structural variations of the proximal femur and acetabulum and concomitant intra-articular joint pathology. Often, a combination of open and arthroscopic techniques are necessary to treat more complex pathomorphologies. Peri- and postoperative recovery after such procedures can pose a substantial challenge to the patient, and a dedicated, thoughtful approach may reduce setbacks, limit morbidity, and help optimize functional outcomes. Evidence Acquisition: PubMed and CINAHL databases were searched to identify relevant scientific and review articles through December 2014 using the search terms hip preservation, labrum, surgical dislocation, femoroacetabular impingement, postoperative rehabilitation, peri-acetabular osteotomy, and rotational osteotomy. Reference lists of included articles were reviewed to locate additional references of interest. Study Design: Clinical review. Level of Evidence: Level 4. Results: Hip preservation procedures and appropriate rehabilitation have allowed individuals to return to a physically active lifestyle. Conclusion: Effective postoperative rehabilitation must consider modifications and precautions specific to the particular surgical techniques used. Proper postoperative rehabilitation after hip preservation surgery may help optimize functional recovery and maximize clinical success and patient satisfaction. PMID:26733593

  7. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table.

    PubMed

    Matta, Joel M; Shahrdar, Cambize; Ferguson, Tania

    2005-12-01

    Dislocation remains the leading early complication of total hip arthroplasty; surgical approach and implant positioning have been recognized as factors influencing total hip arthroplasty stability. We describe a total hip arthroplasty technique done through a single, tissue sparing anterior approach that allows implantation of the femoral and acetabular components without detaching or sectioning any of the muscles and tendons around the hip joint. A series of 437 consecutive, unselected patients who had 494 primary total hip arthroplasty surgeries done through an anterior approach on an orthopaedic table from September 1996 to September 2004 was reviewed. There were 54 hybrid and 442 uncemented hips in the 437 patients (57 bilateral). The average patient age was 64 years. Radiographic analysis showed an average abduction angle of 42 degrees , with 96% in the range of 35 degrees to 50 degrees abduction. The average cup anteversion was 19 degrees with 93% within the target range of 10 degrees to 25 degrees . Postoperative leg length discrepancy averaged 3 +/- 2 mm (range, 0-26 mm). Three patients sustained dislocations for an overall dislocation rate of 0.61%, and no patients required revision surgery for recurrent dislocation. There were 17 operative complications, including one deep infection, three wound infections, one transient femoral nerve palsy, three greater trochanter fracture, two femoral shaft fractures four calcar fractures, and three ankle fractures. Operative time averaged 75 minutes (range 40-150 minutes), and the average blood loss was 350 mL (range, 100-1300 mL). The mean hospital stay was 3 days (range, 1-17 days). The anterior approach on the orthopaedic table is a minimally invasive technique applicable to all primary hip patients. This technique allows accurate and reproducible component positioning and leg-length restoration and does not increase the rate of hip dislocation. Therapeutic study, Level IV-1 (case series). See the Guidelines for

  8. Dislocation dynamics and bacterial growth

    NASA Astrophysics Data System (ADS)

    Amir, Ariel; Nelson, David

    2012-02-01

    Recent experiments have revealed remarkable phenomena in the growth mechanisms of rod-shaped bacteria: proteins associated with the cell wall growth move at constant velocity in circles oriented approximately along the cell circumference (Garner et al., Science 2011, Dom'inguez-Escobar et al., Science 2011, Deng et al., PNAS 2011). We view these dislocations in the partially ordered peptidoglycan structure, and study theoretically the dynamics of these interacting dislocations on the surface of a cylinder. The physics of the nucleation of these dislocations and the resulting dynamics within the model show surprising effects arising from the cylindrical geometry, which are predicted to have important implications on the growth mechanism. We also discuss how long range elastic interactions affect the dynamics of the fraction of active dislocations in the environment.

  9. Pediatric complex divergent elbow dislocation.

    PubMed

    van Wagenberg, Jan-Maarten F; van Huijstee, Pieter J; Verhofstad, Michiel H J

    2011-01-01

    A divergent dislocation of the elbow is a very rare injury, and only a few cases have been described in the literature. It is characterized as a dorsal dislocation of the ulnohumeral joint combined with a lateral dislocation of the proximal radius. All three articulations of the elbow joint are involved. Like in our case, it can be accompanied by an avulsion fracture of the coronoid and a distal radius fracture. For correct understanding of the injury, proper radiographic studies are imperative. In contrast to some earlier reports that advise a conservative approach, we performed a very aggressive operative treatment. To ensure anatomic reconstruction of the elbow, surgical exposure of the various injuries was performed first. After gross reduction of the joint dislocation, definitive osteosynthesis of the distal radius fracture was performed. Subsequently, the coronoid process and lateral collateral ligament could be repaired anatomically, improving the stability of the elbow. An uneventful recovery with excellent elbow motion and stability was achieved.

  10. Femoroacetabular impingement and labral tears in the adolescent hip: diagnosis and surgical advances.

    PubMed

    Friend, L; Kelly, Bryan T

    2009-02-01

    To identify several of the major trends and advancements in the diagnosis and care of the adolescent hip that have recently been responsible for reshaping the standard of care for this group of patients. Recent research has provided an expanded understanding of hip mechanics and anatomy, improved imaging techniques and, in particular, produced a better appreciation of factors that predispose the hip to degenerative changes. It has led to the development and expansion of several treatment options, including hip arthroscopy, safe surgical dislocation of the hip and periacetabular rotational osteotomy. An appreciation of emerging trends in the diagnosis and treatment of adolescent hip problems is important, as prompt recognition of and intervention for certain hip disorders may prevent ongoing injury and avoid or ameliorate chronic conditions associated with the development of degenerative joint changes and osteoarthritis.

  11. Habitual dislocation of patella: A review

    PubMed Central

    Batra, Sumit; Arora, Sumit

    2014-01-01

    Habitual dislocation of patella is a condition where the patella dislocates whenever the knee is flexed and spontaneously relocates with extension of the knee. It is also termed as obligatory dislocation as the patella dislocates completely with each flexion and extension cycle of the knee and the patient has no control over the patella dislocating as he or she moves the knee1. It usually presents after the child starts to walk, and is often well tolerated in children, if it is not painful. However it may present in childhood with dysfunction and instability. Very little literature is available on habitual dislocation of patella as most of the studies have combined cases of recurrent dislocation with habitual dislocation. Many different surgical techniques have been described in the literature for the treatment of habitual dislocation of patella. No single procedure is fully effective in the surgical treatment of habitual dislocation of patella and a combination of procedures is recommended. PMID:25983506

  12. Risk factors for early redislocation after primary treatment of developmental dysplasia of the hip: Is there a protective influence of the ossific nucleus?

    PubMed Central

    Bhaskar, Atul; Desai, Hardik; Jain, Gaurav

    2016-01-01

    Background: Re-dislocation after primary treatment of developmental dysplasia of the hip is a serious complication. We analyzed the various risk factors that contribute to re-dislocation, and whether the bony ossific nucleus (ON) confers increased stability against re-dislocation. Materials and Methods: Fifty-five children (60 hips) were classified into three treatment groups: Closed reduction (CR) in 15 children (17 hips), open reduction (OR) in 26 children (28 hips), and OR with bony surgery (ORB) in 14 children (15 hips). The mean age at initial treatment was 16 months (range 6–36 months). Fifty-one hips and 9 hips were Tonnis Grade 4 and 3, respectively. The mean preoperative acetabular index (AI) was 44.82° (range 32°–56°) for the study group. At initial treatment, bony ON was absent in 8 hips and present in 52 hips. Results: No hip developed stiffness and pain after primary treatment. Although the AI index, Tonnis grade, and absence of ossific nucleus were higher in the re-dislocated groups, this was not statistically significant. Excluding the re-dislocations, four children had a fair outcome, 11 had good outcome, and 36 had excellent outcome as per McKay's criteria. In the CR group (17 hips), two children (2 hips) with absent ON had re-dislocation. In the OR group (28 hips), three re-dislocations were seen (three children) at 3, 5, and 7 months, respectively. Two of these had an absent bony ON. In the ORB group (15 hips), one late sub-luxation occurred in a child with absent ON. The mean preoperative AI for the re-dislocated and located group was 44.66° (range 42°–48°) and 44.53° (range 39°–56°), respectively. The postoperative AI was 34.53. Conclusion: The experience of the treating surgeon and technical factors play an overwhelming role in preventing early dislocation. The absence of ON should perhaps alert the surgeon for enhanced spica care, postoperative splinting, and meticulous intra-operative management. PMID:27746489

  13. Hip disease in the young, active patient: evaluation and nonarthroplasty surgical options.

    PubMed

    Sierra, Rafael J; Trousdale, Robert T; Ganz, Reinhold; Leunig, Michael

    2008-12-01

    As a distinct entity, femoroacetabular impingement has been suggested to be a preosteoarthritic mechanism. The condition occurs when the proximal femur repeatedly comes into contact with the native acetabular rim during normal hip range of motion. Early diagnosis and surgical management are imperative to delay degenerative changes associated with these conditions. Femoroacetabular impingement is most prevalent in young, active patients. Physical examination should include evaluation of gait and foot progression angle, as well as leg length measurement, hip range of motion, and abductor strength. Imaging studies, including plain radiographs and magnetic resonance arthrography, aid in accurate diagnosis. Surgical treatment options include surgical hip dislocation, periacetabular osteotomy, and hip arthroscopy.

  14. Hip psychometrics.

    PubMed

    Baldwin, Peter; Bernstein, Joseph; Wainer, Howard

    2009-07-30

    When data are abundant relative to the number of questions asked of them, answers can be formulated using little more than those data. But when data grow more sparse, so too does our tendency to lean on strong models to help us draw inferences. In this research we show how a strong item response model embedded within a fully Bayesian framework allows us to answer two important questions about the reliability and consistency of the clinical diagnosis of hip fractures from very limited data. We also show how the model automatically adjusts diagnoses for biases among the surgeons judging the radiographs. This research illustrates how a Bayesian approach expands the range of problems on which item response models can profitably be used.

  15. Dislocation sources in ordered intermetallics

    SciTech Connect

    Yoo, M.H.; Appel, F.; Wagner, R.; Mecking, H.

    1996-09-01

    An overview on the current understanding of dislocation sources and multiplication mechanisms is made for ordered intermetallic alloys of the L1{sub 2}, B2, and D0{sub 19} structures. In L1{sub 2} alloys, a large disparity of edge/screw segments in their relative mobility reduces the efficiency of a Frank-Read Type multiplication mechanism. In Fe-40%Al of the B2 structure, a variety of dislocation sources are available for <111> slip, including ones resulting from condensation of thermal vacancies. In NiAl with the relatively high APB energy, <100> dislocations may result from the dislocation decomposition reactions, the prismatic punching out from inclusion particles, and/or steps and coated layers of the surface. Internal interfaces often provide sites for dislocation multiplication, e.g., grain boundaries, sub-boundaries in Ni{sub 3}Ga, NiAl and Ti{sub 3}Al, and antiphase domain boundaries in Ti{sub 3}Al. As for the crack tip as a dislocation source, extended SISFs trailed by super-Shockley partials emanating form the cracks in Ni{sub 3}Al and Co{sub 3}Ti are discussed in view of a possible toughening mechanism.

  16. On the permanent hip-stabilizing effect of atmospheric pressure.

    PubMed

    Prietzel, Torsten; Hammer, Niels; Schleifenbaum, Stefan; Kaßebaum, Eric; Farag, Mohamed; von Salis-Soglio, Georg

    2014-08-22

    Hip joint dislocations related to total hip arthroplasty (THA) are a common complication especially in the early postoperative course. The surgical approach, the alignment of the prosthetic components, the range of motion and the muscle tone are known factors influencing the risk of dislocation. A further factor that is discussed until today is atmospheric pressure which is not taken into account in the present THA concepts. The aim of this study was to investigate the impact of atmospheric pressure on hip joint stability. Five joint models (Ø 28-44 mm), consisting of THA components were hermetically sealed with a rubber capsule, filled with a defined amount of fluid and exposed to varying ambient pressure. Displacement and pressure sensors were used to record the extent of dislocation related to intraarticular and ambient pressure. In 200 experiments spontaneous dislocations of the different sized joint models were reliably observed once the ambient pressure was lower than 6.0 kPa. Increasing the ambient pressure above 6.0 kPa immediately and persistently reduced the joint models until the ambient pressure was lowered again. Displacement always exceeded half the diameter of the joint model and was independent of gravity effects. This experimental study gives strong evidence that the hip joint is permanently stabilized by atmospheric pressure, confirming the theories of Weber and Weber (1836). On basis of these findings the use of larger prosthetic heads, capsular repair and the deployment of an intracapsular Redon drain are proposed to substantially decrease the risk of dislocation after THA.

  17. Total hip arthroplasty.

    PubMed Central

    Siopack, J S; Jergesen, H E

    1995-01-01

    Total hip arthroplasty, or surgical replacement of the hip joint with an artificial prosthesis, is a reconstructive procedure that has improved the management of those diseases of the hip joint that have responded poorly to conventional medical therapy. In this review we briefly summarize the evolution of total hip arthroplasty, the design and development of prosthetic hip components, and the current clinical indications for this procedure. The possible complications of total hip arthroplasty, its clinical performance over time, and future directions in hip replacement surgery are also discussed. Images PMID:7725707

  18. On the hierarchy of interfacial dislocation structure

    NASA Astrophysics Data System (ADS)

    Balluffi, R. W.; Olson, G. B.

    1985-04-01

    Many different types of dislocations have been defined in dislocation models for grain boundaries and interphase boundaries. It is emphasized that there is no unique dislocation model for a boundary, and that the formal dislocation content depends upon the choice of the lattice correspondence relating the adjoining lattices. However, it is concluded that no problems of real physical significance arise from this lack of uniqueness. “Best≓, or most useful, descriptions often exist, and these are discussed. A hierarchy consisting of four different types of interfacial dislocations may be distinguished, which is useful in describing the dislocation content of interfaces. These entities are termed: (1) primary interfacial dislocations; (2) secondary interfacial dislocations; (3) coherency interfacial dislocations; and (4) translational interfacial dislocations. While there may be a lack of agreement on terminology in the literature, it is believed that these dislocation types are distinguishable and play unique roles in useful dislocation models for interfaces. Detailed descriptions of these dislocation types are given, and actual examples in real interfaces are presented. It is concluded that dislocation descriptions of interface structures become of purely formal significance in the limit of fully incoherent interfaces since the cores are then delocalized. The utility of various dislocation descriptions therefore depends on the degree to which various types of local coherency exist.

  19. Pathological fracture dislocation of the acetabulum in a patient with neurofibromatosis-1

    PubMed Central

    Saibaba, Balaji; Sen, Ramesh Kumar; Sharma, Manish; Nahar, Uma

    2016-01-01

    Skeletal neurofibromatosis (NF) commonly manifests as scoliosis and tibial dysplasias. NF affecting the pelvic girdle is extremely rare. Pathological fracture of the acetabulum leading to anterior hip dislocation in a patient with NF-1 has never been reported in the literature. The paper presents the clinical symptomatology, the course of management and the successful outcome of such a rare case of NF-1. Histopathological and immunohistochemistry studies showing abundant spindle cells, which are S-100 positive and of neural origin are the classical hallmarks of neurofibromatous lesions. Tumor resection and iliofemoral arthrodesis can be considered as a valid option in young patients with pathological fracture dislocation of the acetabulum. PMID:26955185

  20. Profile of hip arthroplasty patients in a teaching hospital.

    PubMed

    Goveia, Vania Regina; Mendoza, Isabel Yovana Quispe; Couto, Bráulio Roberto Gonçalves Marinho; Ferreira, Jose Antonio Guimarães; Paiva, Edson Barreto; Guimarães, Gilberto Lima; Stoianoff, Maria Aparecida Resende

    2015-01-01

    to characterize the epidemiological profile of patients undergoing hip replacement, primary or revisional. we conducted a retrospective, descriptive study, including hip arthroplasties performed from January 2009 to June 2012 in a Belo Horizonte teaching hospital, Minas Gerais State - MG, Brazil. Data were analyzed using descriptive statistics. orthopedic procedures represented 45% of the operations at the hospital in the period, 1.4% hip arthroplasties. There were 125 hip replacements, 85 total, 27 partial and 13 reviews. Among the patients, 40% were male and 60% were female. Age ranged between 20 and 102 years, mean and median of 73 and 76 years, respectively. The most frequent diagnosis (82%) was femoral neck fracture by low-energy trauma caused by falling form standing position. In 13 revision operations, 12 required removal of the prosthesis. The infectious complication led to revision in 54% of the time, followed by dislocation (15%), peri-prosthetic fracture (15%) and aseptic loosening (15%). The infection etiologic agent was identified in 43% of occasions. The average length of the prosthesis to a revision operation was eight months. patients undergoing hip arthroplasty are elderly, with femoral neck fracture caused by falling form standing position, affecting more women. The incidence of hip prosthesis loosening was 10%. The main cause of the infection was loosening. The incidence of revisional hip arthroplasty was 10% and the incidence of hospital mortality in patients undergoing hip arthroplasty was 7.2%.

  1. Is soft tissue repair a right choice to avoid early dislocation after THA in posterior approach?

    PubMed

    Zhou, Yiqin; Cao, Shiqi; Li, Lintao; Narava, Manoj; Fu, Qiwei; Qian, Qirong

    2017-05-19

    Dislocation is the second most common complication after total hip arthroplasty (THA). The effectiveness of soft tissue repair to reduce dislocation rate is still debated and thus a meta-analysis was conducted. A systematic search in PubMed, Embase, and Cochrane databases was conducted for this meta-analysis. clinical comparative trials on the use of soft tissue repair including rotators and capsule repair in primary THA. The main data outcome were the incidences of early hip dislocation after primary THA. HSS score, incidence of other complications was also included in the outcomes. A total of 4816 cases were included for the analysis from ten studies (3 RCTs/7 Retrospective trials). Overall, the soft tissue repair group showed a significant lower early dislocation rate and higher HSS score compared to the no repair group; but no significant difference was observed between the two groups in regards to the early dislocation rate in RCT studies only. The capsule repair group showed a significant lower early dislocation rate than no capsule repair group while no significant difference was observed between the rotators repair group and no rotators repair group. In all included studies, 4 greater trochanter fractures, 2 sciatic nerve palsies and 1 infection were reported in soft tissue repair group while no cases were observed in the no repair group. The efficacy of soft tissue repair is positive but still not conclusive to reduce the early dislocation rate after primary THA while soft tissue repair may bring more other complications. Capsule repair seems more effective than rotators repair only.

  2. The use of a constrained cementless acetabular component for instability in total hip replacement.

    PubMed

    Rady, Ahmad Emad; Asal, Mohammed Kamal; Bassiony, Ayman Abdelaziz

    2010-01-01

    Recurrent dislocation after total hip arthroplasty is a disabling complication that can be difficult to treat. We evaluated the early clinical and radiographic outcome associated with the use of a constrained acetabular component for instability in total hip arthroplasty. Fifteen patients underwent either primary or revision total hip arthroplasty with a cementless constrained acetabular component for different indications. The mean patient age at surgery was 57.4 years and the mean clinical and radiological follow-up period was 26.4 months. Clinical assessment was performed by the Harris hip score and at the latest follow up patients reported outcome using the Oxford hip score questionnaire. All radiographs were evaluated for evidence of loosening. Only one patient experienced redislocation with the constrained prosthesis. The average Harris hip score increased from a preoperative mean of 22 (range, 16 - 36) to a postoperative mean of 85 (range, 66-94). Preoperatively, the mean Oxford Hip Score was 48.6, which decreased to 20.5 at the final examination. All but one of the 15 hips had a well-fixed, stable cup. Femoral component stability with bone ingrowth was achieved in 10 cases. A constrained acetabular component is an effective option for the treatment of hip instability in primary and revision arthroplasty in those at high risk of dislocation. The potential for aseptic loosening requires evaluation by long term studies.

  3. Dislocation Multi-junctions and Strain Hardening

    SciTech Connect

    Bulatov, V; Hsiung, L; Tang, M; Arsenlis, A; Bartelt, M; Cai, W; Florando, J; Hiratani, M; Rhee, M; Hommes, G; Pierce, T; Diaz de la Rubia, T

    2006-06-20

    At the microscopic scale, the strength of a crystal derives from the motion, multiplication and interaction of distinctive line defects--dislocations. First theorized in 1934 to explain low magnitudes of crystal strength observed experimentally, the existence of dislocations was confirmed only two decades later. Much of the research in dislocation physics has since focused on dislocation interactions and their role in strain hardening: a common phenomenon in which continued deformation increases a crystal's strength. The existing theory relates strain hardening to pair-wise dislocation reactions in which two intersecting dislocations form junctions tying dislocations together. Here we report that interactions among three dislocations result in the formation of unusual elements of dislocation network topology, termed hereafter multi-junctions. The existence of multi-junctions is first predicted by Dislocation Dynamics (DD) and atomistic simulations and then confirmed by the transmission electron microscopy (TEM) experiments in single crystal molybdenum. In large-scale Dislocation Dynamics simulations, multi-junctions present very strong, nearly indestructible, obstacles to dislocation motion and furnish new sources for dislocation multiplication thereby playing an essential role in the evolution of dislocation microstructure and strength of deforming crystals. Simulation analyses conclude that multi-junctions are responsible for the strong orientation dependence of strain hardening in BCC crystals.

  4. Dislocation multi-junctions and strain hardening.

    PubMed

    Bulatov, Vasily V; Hsiung, Luke L; Tang, Meijie; Arsenlis, Athanasios; Bartelt, Maria C; Cai, Wei; Florando, Jeff N; Hiratani, Masato; Rhee, Moon; Hommes, Gregg; Pierce, Tim G; de la Rubia, Tomas Diaz

    2006-04-27

    At the microscopic scale, the strength of a crystal derives from the motion, multiplication and interaction of distinctive line defects called dislocations. First proposed theoretically in 1934 (refs 1-3) to explain low magnitudes of crystal strength observed experimentally, the existence of dislocations was confirmed two decades later. Much of the research in dislocation physics has since focused on dislocation interactions and their role in strain hardening, a common phenomenon in which continued deformation increases a crystal's strength. The existing theory relates strain hardening to pair-wise dislocation reactions in which two intersecting dislocations form junctions that tie the dislocations together. Here we report that interactions among three dislocations result in the formation of unusual elements of dislocation network topology, termed 'multi-junctions'. We first predict the existence of multi-junctions using dislocation dynamics and atomistic simulations and then confirm their existence by transmission electron microscopy experiments in single-crystal molybdenum. In large-scale dislocation dynamics simulations, multi-junctions present very strong, nearly indestructible, obstacles to dislocation motion and furnish new sources for dislocation multiplication, thereby playing an essential role in the evolution of dislocation microstructure and strength of deforming crystals. Simulation analyses conclude that multi-junctions are responsible for the strong orientation dependence of strain hardening in body-centred cubic crystals.

  5. Dislocations and other topological oddities

    NASA Astrophysics Data System (ADS)

    Pieranski, Pawel

    2016-03-01

    We will show that the book Dislocations by Jacques Friedel, published half a century ago, can still be recommended, in agreement with the author's intention, as a textbook ;for research students at University and for students at engineering schools as well as for research engineers;. Indeed, today dislocations are known to occur not only in solid crystals but also in many other systems discovered more recently such as colloidal crystals or liquid crystals having periodic structures. Moreover, the concept of dislocations is an excellent starting point for lectures on topological defects occurring in systems equipped with order parameters resulting from broken symmetries: disclinations in nematic or hexatic liquid crystals, dispirations in chiral smectics or disorientations in lyotropic liquid crystals. The discussion of dislocations in Blue Phases will give us an opportunity to call on mind Sir Charles Frank, friend of Jacques Friedel since his Bristol years, who called these ephemeral mesophases ;topological oddities;. Being made of networks of disclinations, Blue Phases are similar to Twist Grain Boundary (TGB) smectic phases, which are made of networks of screw dislocations and whose existence was predicted by de Gennes in 1972 on the basis of the analogy between smectics and superconductors. We will stress that the book by Jacques Friedel contains seeds of this analogy.

  6. [Total hip arthroplasty for non-functional bony ankylosed hip in young and middle-aged patients].

    PubMed

    Fu, Yingxu; Yu, Boyong; Asihaerjiang-Maimaitiyiming; Cao, Li; Aili-Rehei

    2014-09-01

    To explore the effectiveness of total hip arthroplasty (THA) for non-functional bony ankylosed hip in young and middle-aged patients. Between January 2010 and March 2013, 14 cases (19 hips) of non-functional bony ankylosed hip were treated by THA. There were 9 males and 5 females, aged 37.5 years on average (range, 23- 58 years). The left hip was involved in 6 cases, the right hip in 3 cases, and bilateral hips in 5 cases. The causes were tuberculosis in 2 patients, ankylosing spondylitis in 5 patients, traumatic arthritis in 5 patients, osteoarthritis in 1 patient, and suppurative infection in 1 patient. The disease duration was 7-18 years with an average of 8.9 years. Flexion stiffness was observed in 10 hips, flexion abduction stiffness in 6 hips, and flexion adduction shortening stiffness in 3 hips. Only 5 patients could walk with a crutch before operation. Harris hip score was 24.368 ± 7.625. The average operation time was 63.4 minutes (range, 50-90 minutes). The average intraoperative blood loss was 196.8 mL (range, 100-400 mL). Patients obtained primary healing of incision; no complication of neurovascular injury, fracture, joint dislocation, or infection occurred. All patients were followed up 2.2 years on average (range, 1 year to 4 years and 3 months). The Harris score was 86.837 ± 7.742 at last follow- up, showing significant difference when compared with preoperative score (t = -41.956, P = 0.000). The results were excellent in 5 hips, good in 11 hips, fair in 2 hips, and poor in 1 hip, with an excellent and good rate of 84.2%. All patients could basically take care of themselves; 2 patients could walk with crutch, and the other patients could walk without crutch. X-ray films showed that prosthesis was in good position; no shifting, loosening, or sinking was found. Heterotopic ossification occurred in 2 hips. THA is an effective surgical approach to treat non-functional bony ankylosed hip in young and middle- aged patients.

  7. Total hip arthroplasty in the ankylosed hip.

    PubMed

    Swanson, Megan A; Huo, Michael H

    2011-12-01

    Altered biomechanics secondary to hip ankylosis often result in degeneration of the lumbar spine, ipsilateral knee, and contralateral hip and knee. Symptoms in these joints may be reduced with conversion total hip arthroplasty (THA) of the ankylosed hip. THA in the ankylosed hip is a technically challenging procedure, and the overall clinical outcome is generally less satisfactory than routine THA performed for osteoarthritis and other etiologies. Functional integrity of the hip abductor muscles is the most important predictor of walking ability following conversion THA. Many patients experience persistent limp, and it can take up to 2 years to fully assess final functional outcome. Risk factors cited for increased risk of failed THA include prior surgical ankylosis and age <50 years at the time of conversion THA.

  8. A continuum theory of edge dislocations

    NASA Astrophysics Data System (ADS)

    Berdichevsky, V. L.

    2017-09-01

    Continuum theory of dislocation aims to describe the behavior of large ensembles of dislocations. This task is far from completion, and, most likely, does not have a ;universal solution;, which is applicable to any dislocation ensemble. In this regards it is important to have guiding lines set by benchmark cases, where the transition from a discrete set of dislocations to a continuum description is made rigorously. Two such cases have been considered recently: equilibrium of dislocation walls and screw dislocations in beams. In this paper one more case is studied, equilibrium of a large set of 2D edge dislocations placed randomly in a 2D bounded region. The major characteristic of interest is energy of dislocation ensemble, because it determines the structure of continuum equations. The homogenized energy functional is obtained for the periodic dislocation ensembles with a random contents of the periodic cell. Parameters of the periodic structure can change slowly on distances of order of the size of periodic cells. The energy functional is obtained by the variational-asymptotic method. Equilibrium positions are local minima of energy. It is confirmed the earlier assertion that energy density of the system is the sum of elastic energy of averaged elastic strains and microstructure energy, which is elastic energy of the neutralized dislocation system, i.e. the dislocation system placed in a constant dislocation density field making the averaged dislocation density zero. The computation of energy is reduced to solution of a variational cell problem. This problem is solved analytically. The solution is used to investigate stability of simple dislocation arrays, i.e. arrays with one dislocation in the periodic cell. The relations obtained yield two outcomes: First, there is a state parameter of the system, dislocation polarization; averaged stresses affect only dislocation polarization and cannot change other characteristics of the system. Second, the structure of

  9. [Radiocarpal dislocation after a trivial injury].

    PubMed

    Jiménez-Jiménez, I J; Caballero-Martel, J R; Ojeda-Castellano, J

    2015-01-01

    Radiocarpal dislocation is an extremely uncommon injury in Traumatology, and is usually produced by high energy trauma. There are two types of dislocation, type I: pure radiocarpal dislocation and type II: fracture-dislocation. The gold standard treatment according to the literature is surgical treatment fixing the fractures and repairing the injured ligaments. We report a clinical case of radiocarpal dislocation type I in a healthy 19 year-old male after a minor trauma. The dislocation was reduced by traction, and the wrist immobilized in a plaster cast. The functional outcome 12 months after the injury was excellent. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  10. [Increased incidence of developmental hip dysplasia in hypertrophic newborn infants].

    PubMed

    Peschgens, T; Skopnik, H; Casser, H R; Rauschning-Sikora, K; Heimann, G

    1993-01-01

    "Lack of space" in utero is considered to be a major factor in the aetiology of the congenital dislocation of the hip. This study tries to answer the question whether hypertrophy of a newborn has to be regarded as a risk factor on the basis of the principle mentioned above. The results of postnatal clinical and sonographical examination performed on 98 large-for-gestational-age (LGA-) newborn were compared to those performed on 310 newborn children during a non selective screening program. Among the LGA-newborn pathological hip joints were found more often mainly female LGA-newborn infants were affected. It seemed that the birth weight did not correlate to the extent of the retardation of the hip joint development. It was again confirmed that the restriction to only clinical diagnostic procedures in the neonatal period is not effective in the early diagnosis of the malformation. Hypertrophy of a newborn has to be considered as a risk factor behind the development of congenital dislocation of the hip. It is recommended to examine all LGA-newborn infants post partum by clinical and most importantly also by sonographical means to recognize a retardation of hip joint development.

  11. The irreducible floating hip: a unique presentation of a rare injury.

    PubMed

    Tiedeken, Nathan C; Saldanha, Vilas; Handal, John; Raphael, James

    2013-10-04

    A floating hip injury occurs in the setting of poly-trauma and is a rare and difficult problem to manage. Floating hip injuries require vigilant attention not only to the osseous injuries but also the surrounding compartments and soft tissue envelope. We report the case of a 35-year-old male with a lower extremity posterior wall acetabular fracture, ipsilateral femoral shaft fracture and a postero-superior hip dislocation. Closed reduction failed, necessitating an open reduction internal fixation of his hip dislocation and acetabular fracture. The patient then developed a thigh compartment syndrome requiring a fasciotomy. Despite the obvious bony injuries, orthopedic surgeons must be vigilant of the neurovascular structures and soft tissues that have absorbed a great amount of force. A treatment plan should be formulated based on the status of the overlying soft tissue, fracture pattern and the patient's physiologic stability. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2013.

  12. The irreducible floating hip: a unique presentation of a rare injury

    PubMed Central

    Tiedeken, Nathan C.; Saldanha, Vilas; Handal, John; Raphael, James

    2013-01-01

    A floating hip injury occurs in the setting of poly-trauma and is a rare and difficult problem to manage. Floating hip injuries require vigilant attention not only to the osseous injuries but also the surrounding compartments and soft tissue envelope. We report the case of a 35-year-old male with a lower extremity posterior wall acetabular fracture, ipsilateral femoral shaft fracture and a postero-superior hip dislocation. Closed reduction failed, necessitating an open reduction internal fixation of his hip dislocation and acetabular fracture. The patient then developed a thigh compartment syndrome requiring a fasciotomy. Despite the obvious bony injuries, orthopedic surgeons must be vigilant of the neurovascular structures and soft tissues that have absorbed a great amount of force. A treatment plan should be formulated based on the status of the overlying soft tissue, fracture pattern and the patient's physiologic stability. PMID:24964321

  13. Thermal effects in dislocation theory

    NASA Astrophysics Data System (ADS)

    Langer, J. S.

    2016-12-01

    The mechanical behaviors of polycrystalline solids are determined by the interplay between phenomena governed by two different thermodynamic temperatures: the configurational effective temperature that controls the density of dislocations, and the ordinary kinetic-vibrational temperature that controls activated depinning mechanisms and thus deformation rates. This paper contains a review of the effective-temperature theory and its relation to conventional dislocation theories. It includes a simple illustration of how these two thermal effects can combine to produce a predictive theory of spatial heterogeneities such as shear-banding instabilities. Its main message is a plea that conventional dislocation theories be reformulated in a thermodynamically consistent way so that the vast array of observed behaviors can be understood systematically.

  14. Multiscale Theory of Dislocation Climb.

    PubMed

    Geslin, Pierre-Antoine; Appolaire, Benoît; Finel, Alphonse

    2015-12-31

    Dislocation climb is a ubiquitous mechanism playing a major role in the plastic deformation of crystals at high temperature. We propose a multiscale approach to model quantitatively this mechanism at mesoscopic length and time scales. First, we analyze climb at a nanoscopic scale and derive an analytical expression of the climb rate of a jogged dislocation. Next, we deduce from this expression the activation energy of the process, bringing valuable insights to experimental studies. Finally, we show how to rigorously upscale the climb rate to a mesoscopic phase-field model of dislocation climb. This upscaling procedure opens the way to large scale simulations where climb processes are quantitatively reproduced even though the mesoscopic length scale of the simulation is orders of magnitude larger than the atomic one.

  15. The Role of Metal-on-Metal Bearings in Total Hip Arthroplasty and Hip Resurfacing: Review Article.

    PubMed

    Sands, David; Schemitsch, Emil H

    2017-02-01

    The current role of metal-on-metal (MoM) bearings in hip arthroplasty remains controversial. The low wear offered by MoM bearings compared to metal-on-polyethylene and the possibility of a lower risk of dislocation with larger head sizes, encouraged a trend towards the re-introduction of the MoM bearing couple. However, recent evidence has shown that not all designs of the MoM bearing have been successful. The purpose of this paper is to provide an update on the use of MoM bearings and address the following issues: (1) the reintroduction of metal-on-metal bearings in total hip arthroplasty, (2) the failure of metal-on-metal bearings in stemmed total hip arthroplasty, (3) the role of metal-on-metal hip resurfacing in modern orthopaedics and (4) metal-on-metal hip resurfacing versus total hip arthroplasty. A literature search strategy was conducted using various search terms in MEDLINE and Embase. The highest quality articles that met the inclusion criteria and best answered the topics of focus of this review were selected. Key search terms included 'metal-on-metal', 'total hip arthroplasty' and 'hip resurfacing'. The initial search retrieved 1240 articles. Twenty-two articles were selected and used in the review. Metal-on-metal hip resurfacing is still a suitable treatment option in specific patient populations with the appropriate implant design and surgical skill, while stemmed metal-on-metal total hip arthroplasty should be avoided in all patient populations. Continued follow-up of patients undergoing metal-on-metal hip resurfacing is critical in order to further understand the long-term outcomes of these patients and why certain complications tend to occur with this procedure.

  16. Treatment of symptomatic greater trochanteric fracture after total hip arthroplasty.

    PubMed

    Peretz, Jeffrey I; Chuang, Michael J; Cerynik, Douglas L; Johanson, Norman A

    2009-08-01

    Isolated greater trochanter fractures after total hip arthroplasty are associated with major comorbidities such as debilitating weakness, pain, and dislocation. No definitive standard of care has been established for these fracture. However, it is well known that reestablishing osseous union in these patients is strongly associated with return of functional status. We report a case of an elderly patient with multiple hip revision surgeries now presenting with unilateral greater trochanter fracture. Treatment incorporated the use of a trochanteric claw plate, cerclage wiring, and adjuvant demineralized bone matrix allograft to achieve successful osseous union. This is the first reported use of adjuvant demineralized bone matrix for fixing these fractures.

  17. Interventions for Hip Pain in the Maturing Athlete

    PubMed Central

    Gomberawalla, M. Mustafa; Kelly, Bryan T.; Bedi, Asheesh

    2014-01-01

    Context: Femoroacetabular impingement (FAI) alters hip mechanics, results in hip pain, and may lead to secondary osteoarthritis (OA) in the maturing athlete. Hip impingement can be caused by osseous abnormalities in the proximal femur or acetabulum. These impingement lesions may cause altered loads within the hip joint, which result in repetitive collision damage or sheer forces to the chondral surfaces and acetabular labrum. These anatomic lesions and resultant abnormal mechanics may lead to early osteoarthritic changes. Evidence Acquisition: Relevant articles from the years 1995 to 2013 were identified using MEDLINE, EMBASE, and the bibliographies of reviewed publications. Level of Evidence: Level 4. Results: Improvements in hip arthroscopy have allowed FAI to be addressed utilizing the arthroscope. Adequately resecting the underlying osseous abnormalities is essential to improving hip symptomatology and preventing further chondral damage. Additionally, preserving the labrum by repairing the damaged tissue and restoring the suction seal may theoretically help normalize hip mechanics and prevent further arthritic changes. The outcomes of joint-preserving treatment options may be varied in the maturing athlete due to the degree of underlying OA. Irreversible damage to the hip joint may have already occurred in patients with moderate to advanced OA. In the presence of preexisting arthritis, these patients may only experience fair or even poor results after hip arthroscopy, with early conversion to hip replacement. For patients with advanced hip arthritis, total hip arthroplasty remains a treatment option to reliably improve symptoms with good to excellent outcomes and return to low-impact activities. Conclusion: Advances in the knowledge base and treatment techniques of intra-articular hip pain have allowed surgeons to address this complex clinical problem with promising outcomes. Traditionally, open surgical dislocations for hip preservation surgery have shown good

  18. The use of a constrained acetabular component to treat instability after total hip arthroplasty.

    PubMed

    Shrader, M Wade; Parvizi, Javad; Lewallen, David G

    2003-11-01

    Recurrent dislocation after total hip arthroplasty is a disabling complication that can be difficult to treat and may not be amenable to nonoperative management. The purpose of the present study was to evaluate the clinical and radiographic outcome associated with the use of a constrained acetabular component as a salvage treatment for instability after hip arthroplasty. We retrospectively reviewed the clinical and radiographic outcome of 110 arthroplasties, in 109 patients, that had been performed with use of a single design of constrained acetabular component. In seventy-nine hips the constrained component was implanted for the treatment of recurrent instability, and in thirty-one hips it was implanted because of absent or grossly deficient soft-tissue attachments that were believed to be associated with a high risk for subsequent instability. The constrained acetabular device eliminated or prevented hip instability in all patients except two, who continued to have sensations of subluxation. The mean Harris hip score improved significantly, from 62.7 points preoperatively to 76.4 points at the time of the latest follow-up (p < 0.0001). There were no instances of dislocation or disassembly of the hip components. Radiographic analysis revealed radiolucent lines around the cup in fifteen hips (14%). There was a total of nine revisions: six for deep infection, two for acetabular component loosening, and one for a periprosthetic fracture of the femur. A constrained acetabular component reliably restores and maintains hip stability in patients with recalcitrant recurrent instability and can dependably prevent dislocation in those who are at high risk because of absent or deficient soft tissues about the hip. However, because of the early appearance of radiolucent lines around some components and concerns about long-term fixation, the use of these devices should be reserved for situations in which other methods are inadequate or have already failed.

  19. Total arthroplasty in displaced dysplastic hips with acetabular reconstruction and femoral shortening - technical note.

    PubMed

    Silva, Paulo; de Oliveira, Leandro Alves; Coelho, Danilo Lopes; do Amaral, Rogério Andrade; Rebello, Percival Rosa; de Moraes, Frederico Barra

    2014-01-01

    To describe a new procedure of total hip replacement in patient with severe developmental dysplasia of the left hip, using technique of acetabular reconstruction with autogenous bone grafts and subtrochanteric shortening femoral osteotomy. Total hip replacement done in January of 2003. The Eftekhar's classification was used and included type D, neglected dislocations. Bone graft incorporated in acetabular shelf and femoral osteotomy. Our contribution is the use of an Allis plate to better fix acetabular grafts, avoiding loosening, and cerclage around bone graft in femoral osteotomy site, which diminish pseudoarthrosis risk. This technique shows efficiency, allowing immediately resolution for this case with pain and range of motion of hip improvement. It also allows the acetabular dysplasia reconstruction, equalization of the limb length (without elevated risk of neurovascular lesion) and repairs the normal hip biomechanics due to the correction of the hip's center of rotation.

  20. LACBED characterization of dislocations in Cu-Al-Ni shape memory alloys processed by powder metallurgy

    NASA Astrophysics Data System (ADS)

    Rodriguez, P. P.; Ibarra, A.; San Jean, J.; Morniro, J. P.; No, M. L.

    2003-10-01

    Powder metallurgy Cu-AI-Ni shape memory alloys show excellent thermomechanical properties, being the fracture behavior close to the one observed in single crystals. However, the microstructural mechanisms responsible of such behavior are still under study. In this paper we present the characterization of the dislocations present in these alloys by Large Angle Convergent Beam Electron Diffraction (LACBED) in two different stages of the elaboration process: after HIP compaction and after hot rolling.

  1. Hip Implant Systems

    MedlinePlus

    ... Medical Devices Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share ... femoral head) is removed and replaced with a prosthetic ball made of metal or ceramic, and the ...

  2. Hip replacement - discharge

    MedlinePlus

    ... surgery to replace all or part of your hip joint with an artificial joint called a prosthesis. This ... You're in the Hospital You had a hip joint replacement surgery to replace all or part of ...

  3. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  4. Central acetabular fracture with dislocation treated by minimally invasive plate osteosynthesis.

    PubMed

    2015-06-01

    Central acetabular fractures with dislocation are usually the result of high-energy trauma, resulting in joint incongruity, and are frequently associated with other injuries. Open reduction and internal fixation has been the standard treatment for acetabular fractures, but it is associated with extensive surgical trauma, and complications such as haematoma formation, iatrogenic nerve injury, and heterotopic ossification. We present the case of a 63-year-old female who sustained a central acetabular fracture of the hip with dislocation as a result of an automobile collision. Closed reduction of the dislocation was performed, and the fracture was managed by minimally invasive plate osteosynthesis using a specially prepared plate. At 01 year postoperatively, radiographs showed the fracture to have been well-healed with good congruity of the joint. However, heterotopic ossification of the joint was noted. The technique allowed reduction of the fracture with minimal surgical trauma.

  5. The importance of acetabular component position in total hip arthroplasty.

    PubMed

    Daines, Brian K; Dennis, Douglas A

    2012-11-01

    Correct acetabular cup position is critical to successful total hip replacement. Unfortunately, malposition of acetabular cups is common and leads to increased rates of dislocation, wear, and ion toxicity. Despite the popularity of Lewinnek's safe zone, the exact target of acetabular abduction and version remains elusive. Differences in functional pelvic position, surgical approach, and femoral anteversion affect the optimal cup position for individual patients. Surgeons need to be aware of pelvic position changes from the supine to lateral decubitus position.

  6. Venous thromboembolism during hip plaster cast immobilisation: review of the literature.

    PubMed

    Struijk-Mulder, M C; Ettema, H B; Heyne, R A J; Rondhuis, J J; Büller, H R; Verheyen, C C P M

    2014-01-01

    There is a paucity of data regarding the risk of deep vein thrombosis during hip plaster cast immobilisation. The purpose of this article was to review the available evidence regarding the incidence of symptomatic venous thromboembolism (VTE) during hip plaster cast immobilisation. All papers describing hip plaster cast immobilisation published in the English literature retrieved from PubMed, EMBASE and the Cochrane database were reviewed. Articles regarding children, hip dysplasia, congenital hip dislocation and Legg-Calvé-Perthes were excluded. A total of three papers were available for analysis. We also describe a case of pulmonary embolism during hip cast immobilisation. The overall incidence of symptomatic VTE during hip plaster cast immobilisation was 0% in 343 patients. The incidence of symptomatic VTE in hip cast brace was 2.3% (range 0-3%). Our systematic review of the literature showed a paucity of data regarding the incidence of VTE during hip plaster cast immobilisation. We describe the first case of pulmonary embolism during hip plaster cast immobilisation. We recommend that patients who are fitted with a hip plaster cast should be routinely screened for additional risk factors. When risk factors are present, patients should be considered for pharmacological thromboprophylaxis.

  7. The epidemiology of shoulder dislocations in Malaysia.

    PubMed

    Yeap, J S; Lee, D J K; Fazir, M; Borhan, T A Muhd; Kareem, B A

    2004-12-01

    The case notes of 102 patients (117 shoulder dislocations) were reviewed retrospectively to improve the understanding of the epidemiology of this common injury. Eighty-one dislocations were primary and 36 dislocations were second or recurrent dislocations. The age distribution was characterized by a peak in male patients aged between 21-30 years. The mean age for males was 30.5 years and 47.7 years for females. The male:female ratio in first time dislocations was 5:2, while it was 5:1 in recurrent dislocations. Ninety-eight percent were anterior dislocations and 2% were posterior dislocations. Greater tuberosity fractures were found in 17 patients and almost half of these patients were aged between 41-50 years. The most common cause of first time dislocation was a direct blow or fall onto the shoulder, accounting for 42 patients (55%). The majority of these patients were aged 40 years and above. Next common cause was motor vehicle accident which occurred mostly in the younger age group. Dislocations due to sporting injuries accounted for only 5.3% of all first time dislocations. Nearly 97% were successfully reduced without a general anaesthesia. Seventy-seven percent of the patients had their shoulders immobilized after reduction, mostly with body strapping only. Fifteen patients (14.7%) were referred for physiotherapy for stiffness. Few operations were performed for recurrent dislocations but surgery does not appear to be well accepted as yet by our patients.

  8. Boundary dislocation structure of crystalline composites

    SciTech Connect

    Regel', V.A.; Stepantsov, E.A.; Tovmasyan, A.B.

    1986-01-01

    The authors perform the first studies of the dislocation structure of intergrowth boundaries and the adjoining regions in the example of crystalline composites of lithium flouride single crystals. It has been established that the intergrowth boundary of a crystalline composite consists of two dislocation networks: a network of immobile dislocations and the usual subboundary that may shift from its original position.

  9. The Hip Restoration Algorithm

    PubMed Central

    Stubbs, Allston Julius; Atilla, Halis Atil

    2016-01-01

    Summary Background Despite the rapid advancement of imaging and arthroscopic techniques about the hip joint, missed diagnoses are still common. As a deep joint and compared to the shoulder and knee joints, localization of hip symptoms is difficult. Hip pathology is not easily isolated and is often related to intra and extra-articular abnormalities. In light of these diagnostic challenges, we recommend an algorithmic approach to effectively diagnoses and treat hip pain. Methods In this review, hip pain is evaluated from diagnosis to treatment in a clear decision model. First we discuss emergency hip situations followed by the differentiation of intra and extra-articular causes of the hip pain. We differentiate the intra-articular hip as arthritic and non-arthritic and extra-articular pain as surrounding or remote tissue generated. Further, extra-articular hip pain is evaluated according to pain location. Finally we summarize the surgical treatment approach with an algorithmic diagram. Conclusion Diagnosis of hip pathology is difficult because the etiologies of pain may be various. An algorithmic approach to hip restoration from diagnosis to rehabilitation is crucial to successfully identify and manage hip pathologies. Level of evidence: V. PMID:28066734

  10. Hip Labral Tear

    MedlinePlus

    ... the outside rim of the socket of your hip joint. In addition to cushioning the hip joint, the labrum acts like a rubber seal or gasket to help hold the ball at the top of your thighbone securely within your hip socket. Athletes who participate in such sports as ...

  11. [Medium-term effectiveness of total hip arthroplasty with straight tapered rectangular femoral prosthesis].

    PubMed

    Liu, Hongwei; Gu, Weidong; Sun, Junying

    2013-05-01

    To investigate the medium-term effectiveness of straight tapered rectangular femoral prosthesis in total hip arthroplasty (THA). Between May 2004 and June 2006, 58 cases (61 hips) of hip joint disease underwent THA with straight tapered rectangular femoral prosthesis and the clinical data of 43 cases (45 hips) followed up more than 6 years were retrospectively analyzed. There were 21 males (23 hips) and 22 females (22 hips) with an average age of 51.6 years (range, 25-75 years), including 12 cases (12 hips) of congenital developmental dysplasia of the hip, 1 case (1 hip) of osteoarthritis secondary to acetabular dysplasia, 1 case (1 hip) of hip deformity after poliomyelitis, 9 cases (9 hips) of femoral neck fractures, 8 cases (8 hips) of avascular necrosis of the femoral head, 8 cases (8 hips) of osteoarthritis of the hip joint, 2 cases (3 hips) of rheumatoid arthritis, and 2 cases (3 hips) of ankylosing spondylitis. Unilateral replacement was performed in 41 cases and bilateral replacement in 2 cases. The Harris score was 41.7 +/-10.4 before operation. X-ray examination was performed to analyze the location of femoral prostheses and evaluate the stability of the prosthesis-bone interface, and Harris score was used to evaluate the hip function. Periprosthetic fracture occurred in 3 hips, and thigh pain in 4 hips after operation. Forty-three cases (45 hips) were followed up 74-99 months (mean, 85 months). Harris score was 87.6 +/- 8.3 at last follow-up, showing significant difference when compared with preoperative score (t=23.14, P=0.00). The X-ray examination showed that 9 hips had heterotopic ossification; bone resorption caused by stress shielding was observed at the proximal femur in 42 hips. But the stability of the prosthesis-bone interface was good; no infection or dislocation occurred; and no revision for aseptic loosening was performed in all cases. The survival rate of the femoral prosthesis was 100% during medium-term follow-up. THA with straight tapered

  12. [History of hip arthroplasty].

    PubMed

    Płomiński, Janusz; Kwiatkowski, Krzysztof

    2007-02-01

    The authors present the history of hip prosthesis in treatment of coxarthrosis. Despite eighty years of experience the problem of gaining good and long-term results still exist and is difficult to solve. Even changing the way on cementless stabilization of prosthesis doesn't has result in solving the problem of aseptic loosening of hip arthroplasty. Problems of wear derbies made the producers find new to reduce particulate debris. The future of hip arthroplasty is connected with hip resurfacing. Moreover, the higher number of primary hip plasty the more prosthesis are loosening. The treatment is far more difficult and more expensive.

  13. Disparity between Clinical and Ultrasound Examinations in Neonatal Hip Screening

    PubMed Central

    Kyung, Bong Soo; Jeong, Woong Kyo; Park, Si Young

    2016-01-01

    Background For early detection of developmental dysplasia of the hip (DDH), neonatal hip screening using clinical examination and/or ultrasound has been recommended. Although there have been many studies on the reliability of both screening techniques, there is still controversy in the screening strategies; clinical vs. selective or universal ultrasound screening. To determine the screening strategy, we assessed the agreement among the methods; clinical examination by an experienced pediatric orthopedic surgeon, sonographic morphology, and sonographic stability. Methods From January 2004 to June 2009, a single experienced pediatric orthopedic surgeon performed clinical hip screenings for 2,686 infants in the neonatal unit and 43 infants who were referred due to impressions of hip dysplasia before 3 months of age. Among them, 156 clinically unstable or high-risk babies selectively received bilateral hip ultrasound examinations performed by the same surgeon using the modified Graf method. The results were analyzed statistically to detect any correlations between the clinical and sonographic findings. Results Although a single experienced orthopedic surgeon conducted all examinations, we detected only a limited relationship between the results of clinical and ultrasound examinations. Ninety-three percent of the clinically subluxatable hips were normal or immature based on static ultrasound examination, and 74% of dislocating hips and 67% of limited abduction hips presented with the morphology below Graf IIa. A total of 80% of clinically subluxatable, 42% of dislocating and 67% of limited abduction hips appeared stable or exhibited minor instability on dynamic ultrasound examination. About 7% of clinically normal hips were abnormal upon ultrasound examination; 5% showed major instability and 3% showed dysplasia above Graf IIc. Clinical stability had small coefficients between ultrasound examinations; 0.39 for sonographic stability and 0.37 for sonographic morphology

  14. Solute drag on perfect and extended dislocations

    NASA Astrophysics Data System (ADS)

    Sills, R. B.; Cai, W.

    2016-04-01

    The drag force exerted on a moving dislocation by a field of mobile solutes is studied in the steady state. The drag force is numerically calculated as a function of the dislocation velocity for both perfect and extended dislocations. The sensitivity of the non-dimensionalized force-velocity curve to the various controlling parameters is assessed, and an approximate analytical force-velocity expression is given. A non-dimensional parameter S characterizing the strength of the solute-dislocation interaction, the background solute fraction ?, and the dislocation character angle ?, are found to have the strongest influence on the force-velocity curve. Within the model considered here, a perfect screw dislocation experiences no solute drag, but an extended screw dislocation experiences a non-zero drag force that is about 10 to 30% of the drag on an extended edge dislocation. The solutes can change the spacing between the Shockley partials in both stationary and moving extended dislocations, even when the stacking fault energy remains unaltered. Under certain conditions, the solutes destabilize an extended dislocation by either collapsing it into a perfect dislocation or causing the partials to separate unboundedly. It is proposed that the latter instability may lead to the formation of large faulted areas and deformation twins in low stacking fault energy materials containing solutes, consistent with experimental observations of copper and stainless steel containing hydrogen.

  15. Evolution of geometrically necessary dislocation density from computational dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Guruprasad, P. J.; Benzerga, A. A.

    2009-07-01

    This paper presents a method for calculating GND densities in dislocation dynamics simulations. Evolution of suitably defined averages of GND density as well as maps showing the spatial nonuniform distribution of GNDs are analyzed under uniaxial loading. Focus is laid on the resolution dependence of the very notion of GND density, its dependence upon physical dimensions of plastically deformed specimens and its sensitivity to initial conditions. Acknowledgments Support from the National Science Foundation (CMMI-0748187) is gratefully acknowledged.

  16. Theory of interacting dislocations on cylinders.

    PubMed

    Amir, Ariel; Paulose, Jayson; Nelson, David R

    2013-04-01

    We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

  17. Theory of interacting dislocations on cylinders

    NASA Astrophysics Data System (ADS)

    Amir, Ariel; Paulose, Jayson; Nelson, David R.

    2013-04-01

    We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

  18. [Imaging of chronic hip pain in adults].

    PubMed

    Chevrot, A; Drapé, J; Godefroy, D; Dupont, A

    2000-03-01

    Adult hip pathologies are mainly represented by the degenerative disease, so called "osteoarthrosis, or more precisely coxarthrosis". The means of imaging are exposed, according to their specific value: X Rays (measurement of the characteristic angles of the adult hip), Arthrography, CT Scanner, Arthro-CT Scanner, MRI, Bone Scintigraphy, Ultrasonography. Clinical findings differentiate a mechanical syndrome and an inflammatory syndrome. The coxarthrosis is the most frequent, under two forms: primary (idiopathic) coxarthrosis and secondary coxarthrosis. Primary (idiopathic) coxarthrosis has a localised narrowing of the joint space, osteophyte formation, subchondral sclerosis, cyst formation. The destruction progresses slowly, in 10 to 15 years leading to a complete destruction. Bilaterality is frequent. it is treated with total hip prosthesis. There is a rapid form (1 to 2 years) (Postel's Disease). Secondary coxarthrosis occurs after architectural vice, chondral diseases, lack of balance between the size of the head and the acetabulum as in the case of previous fracture or dislocation, avascular bone necrosis of the head of the femur, Paget's disease. Calcium pyrophosphate Deposition disease (CPPD) involves mostly aged women, and also leads to cox-arthrosis. Avascular bone necrosis of the head of the femur involves young adults. Bilateral involvement are frequent. MRI is the most sensitive and the most specific means of early diagnosis, The area of bone necrosis appears as well defined modifications of the upper head of the femur, precisely surrounded by a low signal intensity line on both Ti and T2 weighted imaging. MRI shows articular effusion, bone marrow edema. Scintigraphy gives early findings which are a characteristic, but non specific, hot spot. CT scanner is used for hip destruction evaluation. o Algodystrophy: transient osteoporosis of the hip has a cyclic course, lasting 3 to 9 months. MRI shows an inflammatory pattern in the area of the process(dark in

  19. An Insight into Methods and Practices in Hip Arthroplasty in Patients with Rheumatoid Arthritis

    PubMed Central

    Mosleh-shirazi, Mohammad Saeed; Ibrahim, Mazin; Pastides, Philip; Rahman, Habib

    2015-01-01

    Total hip arthroplasty (THA) has improved the quality of life of patients with hip arthritis. Orthopedic community is striving for excellence to improve surgical techniques and postoperative care. Despite these efforts, patients continue facing postoperative complications. In particular, patients with rheumatoid arthritis display a higher risk of certain complications such as dislocation, periprosthetic infection, and shorter prosthesis durability. In this review we present the current knowledge of hip arthroplasty in patients with rheumatoid arthritis with more insight into common practices and interventions directed at enhancing recovery of these patients and current shortfalls. PMID:26236339

  20. Ipsilateral Fracture Shaft Femur with Neglected Dislocation of Prosthesis: A Case Report.

    PubMed

    Jain, Mantu; Bihari, Amar Jyoti; Sriramka, Bhavna

    2013-01-01

    Neglected hip dislocation is rare in today's world and after prosthesis replacement even rarer finding. However such patients may not report to surgeons until they develop secondary complications. Management of such patient's is a challenge to the treating surgeon and need to be tailored suiting to patient's demands, expectations and constraints of financial resources. We did not find a similar case in the electronic and print media and therefore report this case which was innovatively managed. A 60 year farmer presented with fracture shaft femur and ipsilateral dislocation prosthesis of right hip. He had a hemiarthroplasty done for fracture neck of femur in the past but used to walk with a lurch since he started to ambulate after discharge. However he was satisfied despite "some problems" which had caused shortening of his limb. The patient was informed of the various treatment options and their possible complications. He expressed his inability to afford a Total Hip Arthroplasty (THA) at any stage and consented for other options discussed with him. The patient was positioned supine and adductor tenotomy done. Next he was positioned laterally and the fracture was fixed with heavy duty broad dynamic compression plate and screws. The wound was temporarily closed. Now through the previous scar via posterior approach the hip was exposed. The prosthesis was found to be firmly fixed to the proximal femur. The acetabulum was cleared with fibrous tissue. All attempts the prosthesis to relocate the prosthesis failed after several attempts and it was best decided to leave alone. Post operatively period was uneventful. At follow up he refused for any further manoeuvre in future inform of heavy traction and attempts to reduce the same. At one year when he was walking unaided and his X-rays showed that fracture had well united his SF-36 score was PCS - 49.6 and MCS - 51.9. Ipsilateral shaft femur fracture in chronically dislocated prosthesis, done for fracture neck of femur is

  1. Turned head--adducted hip--truncal curvature syndrome.

    PubMed Central

    Hamanishi, C; Tanaka, S

    1994-01-01

    One hundred and eight neonates and infants who showed the clinical triad of a head turned to one side, adduction contracture of the hip joint on the occipital side of the turned head, and truncal curvature, which we named TAC syndrome, were studied. These cases included seven with congenital and five with late infantile dislocations of the hip joint and 14 who developed muscular torticollis. Forty one were among 7103 neonates examined by one of the authors. An epidemiological analysis confirmed the aetiology of the syndrome to be environmental. The side to which the head was turned and that of the adducted hip contracture showed a high correlation with the side of the maternal spine on which the fetus had been lying. TAC syndrome is an important asymmetrical deformity that should be kept in mind during neonatal examination, and may be aetiologically related to the unilateral dislocation of the hip joint, torticollis, and infantile scoliosis which develop after a vertex presentation. Images PMID:8048823

  2. Simultaneous shoulder and elbow dislocation.

    PubMed

    Cobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-05-23

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice.

  3. Simultaneous shoulder and elbow dislocation

    PubMed Central

    Çobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-01-01

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice. PMID:24859563

  4. Hip arthroscopy for challenging deformities: global pincer femoroacetabular impingement.

    PubMed

    Matsuda, Dean K; Gupta, Nikhil; Hanami, Dylan

    2014-04-01

    Pincer femoroacetabular impingement occurs in focal or global forms, the latter having more generalized and typically more extreme acetabular overcoverage. Severe global deformities are often treated with open surgical dislocation of the hip. Arthroscopic technical challenges relate to difficulties with hip distraction; central-compartment access; and instrument navigation, acetabuloplasty, and chondrolabral surgery of the posterior acetabulum. Techniques addressing these challenges are introduced permitting dual-portal hip arthroscopy with central-compartment access, subtotal acetabuloplasty, and circumferential chondrolabral surgery. The modified midanterior portal in combination with a zone-specific sequence of acetabular rim reduction monitored with fluoroscopic templating enables precision subtotal acetabuloplasty. Guidelines for acetabular rim reduction include the following suggested radiographic endpoints: postoperative center-edge angle of 35°, a neutral posterior wall sign, and an anterior margin ratio of 0.5. Arthroscopic zone-specific chondrophobic rim preparation and circumferential labral reparative and reconstructive techniques and tools permit the arthroscopic treatment of these challenging deformities.

  5. Bilateral total hip replacement in arthrogryposis multiplex congenita.

    PubMed

    Dalton, David Michael; Magill, Paul; Mulhall, Kevin James

    2015-11-25

    The authors present a case of bilateral total hip replacements (THRs) in a 56-year-old patient with arthrogryposis multiplex congenita (AMC). The considerations for the perioperative period and the outcome are discussed. Preoperative planning included an anaesthetic review and availability of fiberoptic intubation due to poor mouth opening. Perioperatively, contractures can make positioning and exposure difficult but in this case a standard posterior approach was taken. Particular attention was given to soft tissue balancing given the theoretical risk of dislocation. There were no perioperative complications. Postoperatively there has been improvement in pain and hip scores but the patient has failed to return to work. Objective improvements in range of motion (ROM) have not been made. This experience suggests THR is a safe and effective treatment for osteoarthritic hip pain in patients with AMC but patients should be informed that ROM is unlikely to improve. 2015 BMJ Publishing Group Ltd.

  6. Current Concepts of Using Large Femoral Heads in Total Hip Arthroplasty

    PubMed Central

    Choi, Won Kee; Kim, Jae Jung

    2016-01-01

    Instability and dislocation after total hip arthroplasty are the most common causes of revisions and major complications for failure of inserted prostheses, leading to a reduction in quality of life. Because the use of artificial femoral head sizes smaller than patient's own size is the important cause for dislocation, the use of large femoral head have increased. Femoral head sizes greater than 32 mm offer multiple advantages in physical function and activity levels of patients by improving hip stability, decreasing dislocation rate and increasing range of motion. However, various concerns are encountered including wear debris generation at the trunnion-bore interface and increases in frictional torque and stress over the component-bone interface when using larger head sizes. So, the use of femoral head sizes less than 40 mm is recommended. PMID:27777915

  7. Three-dimensional formulation of dislocation climb

    NASA Astrophysics Data System (ADS)

    Gu, Yejun; Xiang, Yang; Quek, Siu Sin; Srolovitz, David J.

    2015-10-01

    We derive a Green's function formulation for the climb of curved dislocations and multiple dislocations in three-dimensions. In this new dislocation climb formulation, the dislocation climb velocity is determined from the Peach-Koehler force on dislocations through vacancy diffusion in a non-local manner. The long-range contribution to the dislocation climb velocity is associated with vacancy diffusion rather than from the climb component of the well-known, long-range elastic effects captured in the Peach-Koehler force. Both long-range effects are important in determining the climb velocity of dislocations. Analytical and numerical examples show that the widely used local climb formula, based on straight infinite dislocations, is not generally applicable, except for a small set of special cases. We also present a numerical discretization method of this Green's function formulation appropriate for implementation in discrete dislocation dynamics (DDD) simulations. In DDD implementations, the long-range Peach-Koehler force is calculated as is commonly done, then a linear system is solved for the climb velocity using these forces. This is also done within the same order of computational cost as existing discrete dislocation dynamics methods.

  8. Subtrochanteric osteotomy for femoral mal-torsion through a surgical dislocation approach

    PubMed Central

    Kamath, Atul F.; Ganz, Reinhold; Zhang, Hong; Grappiolo, Guido; Leunig, Michael

    2015-01-01

    Missed torsional femur deformities may contribute to reasons for failure after open and more likely arthroscopic hip preservation surgery. A number of surgical approaches have been described for addressing torsion abnormalities. This report describes a subtrochanteric osteotomy technique in a consecutive series of patients with complex hip pathologies, for which intertrochanteric osteotomy is not suitable and precise derotation is required. Subtrochanteric derotation was performed, always in combination with a surgical hip dislocation, in accordance with the authors’ preferred technique. Before osteotomy, a localized decortication was executed. Application of a 4.5-mm broad or narrow plate was undertaken with dynamic compression of the osteotomy. Twenty-eight consecutive subtrochanteric derotational osteotomies were performed in 26 patients. Twenty-one females and five males were treated at an average age of 21.4 years (range, 12–43). Underlying diagnoses included dysplasia, arthrogryposis, cerebral palsy, Down’s syndrome, instability and impingement. The decision to perform derotation was for antetorsion over 20° or less than 0° (retrotorsion). Patients were followed clinically and radiographically till final follow-up. All patients went on to successful osteotomy union. There were two initial failures: one delayed union prompting revision fixation in a chronic smoker and one plate failure due to self-accelerated weight-bearing in a patient status post successful contralateral derotational osteotomy. Rotational deformity of the femur must be considered in the patient undergoing hip preservation surgery. This technique of subtrochanteric derotational osteotomy, with adjunctive surgical hip dislocation, is applicable and reproducible in the setting of complex hip pathologies. Level of evidence: IV, case series. PMID:27011816

  9. The Exeter Contemporary flanged cemented acetabular component in primary total hip arthroplasty.

    PubMed

    Maggs, J L; Smeatham, A; Whitehouse, S L; Charity, J; Timperley, A J; Gie, G A

    2016-03-01

    We report on the outcome of the Exeter Contemporary flanged cemented all-polyethylene acetabular component with a mean follow-up of 12 years (10 to 13.9). This study reviewed 203 hips in 194 patients. 129 hips in 122 patients are still in situ; 66 hips in 64 patients were in patients who died before ten years, and eight hips (eight patients) were revised. Clinical outcome scores were available for 108 hips (104 patients) and radiographs for 103 hips (100 patients). A retrospective review was undertaken of a consecutive series of 203 routine primary cemented total hip arthroplasties (THA) in 194 patients. There were no acetabular component revisions for aseptic loosening. Acetabular revision was undertaken in eight hips. In four hips revision was necessitated by periprosthetic femoral fractures, in two hips by recurrent dislocation, in one hip for infection and in one hip for unexplained ongoing pain. Oxford and Harris hip scores demonstrated significant clinical improvement (all p < 0.001). Radiolucent lines were present in 37 (36%) of the 103 acetabular components available for radiological evaluation. In 27 of these, the line was confined to zone 1. No component had migrated. Kaplan-Meier survivorship, with revision for aseptic loosening as the endpoint, was 100% at 12.5 years and for all causes was 97.8% (95% confidence interval 95.6 to 100) when 40 components remained at risk. The Exeter Contemporary flanged cemented acetabular component demonstrates excellent survivorship at 12.5 years. The Exeter Contemporary flanged cemented acetabular component has excellent clinical outcomes and survivorship when used with the Exeter stem in total hip arthroplasty. ©2016 The British Editorial Society of Bone & Joint Surgery.

  10. Dynamic long leg casting fixation for treating 12- to 18-month-old infants with developmental dysplasia of the hip.

    PubMed

    Cai, Zhencun; Li, Lianyong; Zhang, Lijun; Ji, Shijun; Zhao, Qun

    2017-02-01

    Objective To evaluate the effect of dynamic long leg casting in paediatric patients with developmental dysplasia of hip (DDH) diagnosed at 12-18 months. Methods The adductor tenotomy, closed reduction, and dynamic long leg casting method was adopted to treat paediatric patients with DDH. The hips were divided into four groups according to the Tonnis radiographic dislocation classification. Groups were also classified according to the baseline acetabular index (AI): 30°-35°, 36°-40°, and > 40°. The outcomes of the reductions were evaluated according to McKay's hip function criteria and Severin's radiological criteria. Results A total of 246 patients (339 hips) had complete follow-up data. After 3 months of orthosis fixation, the results were satisfactory in 264 hips (77.88%). Hip function was rated as 'excellent' or 'good' in 43 of 51 (84.31%) Tonnis type 1 hips, 125 of 155 (80.65%) type 2 hips, 70 of 90 (77.78%) type 3 hips, and 34 of 43 (79.07%) type 4 hips. The higher the baseline AI, the lower the rates of 'excellent' and 'good' hip function. Favourable radiological results (Severin types I and II) were found in 266 of 339 (78.47) hips. Conclusions Dynamic long leg casting is an effective method for treating patients with DDH aged 12-18 months at diagnosis.

  11. Dementia and Hip Fractures

    PubMed Central

    Friedman, Susan M.; Menzies, Isaura B.; Bukata, Susan V.; Mendelson, Daniel A.; Kates, Stephen L.

    2010-01-01

    Dementia and hip fractures are 2 conditions that are seen primarily in older adults, and both are associated with substantial morbidity and mortality. An individual with dementia is up to 3 times more likely than a cognitively intact older adult to sustain a hip fracture. This may occur via several mechanisms, including (1) risk factors that are common to both outcomes; (2) the presence of dementia increasing hip fracture incidence via intermediate risk factors, such as falls, osteoporosis, and vitamin D; and (3) treatment of dementia causing side effects that increase hip fracture risk. We describe a model that applies these 3 mechanisms to explain the relationship between dementia and hip fractures. Comprehensive understanding of these pathways and their relative influence on the outcome of hip fracture will guide the development of effective interventions and potentially improve prevention efforts. PMID:23569663

  12. Primary ileus after total hip arthroplasty: rare complication or sentinel event?

    PubMed

    Vannelli, Alberto; Laveneziana, Domenico; Rampa, Mario; Battaglia, Luigi; Leo, Ermanno

    2011-09-01

    The incidence of hip dislocation after primary total hip arthroplasty (THA) has been reported to range from 1 to 25% in THA revision. Here, we explore the hypothesis that there is a correlation between postoperative ileus (POI) and THA dislocation, with POI after THA possibly representing a sentinel event. We retrospectively identified a cohort of 529 consecutive patients who underwent hip arthroplasty from 2008 to 2010. Of them, 251 were male and 278 were female, and a mean average for age of 71.5 (range 65-76). In particular, 19 THA patients showed signs of gastrointestinal complications, and therapeutic consultation was performed with the onset of the first intestinal symptom. Of these 19 patients, 3 THA patients developed POI within 1 week after surgical treatment. A conservative treatment was practised and it seemed to improve the condition: canalization returned and all patients were discharged from the hospital. Unfortunately, two of these patients were readmitted after 2 weeks due to THA dislocation and they underwent THA revision and were discharged from the hospital 7 days later. Follow-up revealed no further problems at 6 months. Our clinical experience with these post-THA primary ileus patients raises the possibility that intra-abdominal symptoms represent a sentinel event in THA dislocation. THA dislocation using neuronal pathway of immunomodulation may modulate POI. Since the risk of THA dislocation is the greatest in the first 3 months after hip arthroplasty, the surgeon should be familiar with the relationship between THA and various pelvic and visceral complications to ensure that POI remains only a rare complication.

  13. Midterm Outcome of Cementless Total Hip Arthroplasty in Crowe IV-Hartofilakidis Type III Developmental Dysplasia of the Hip.

    PubMed

    Mu, Wenbo; Yang, Desheng; Xu, Boyong; Mamtimin, Askar; Guo, Wentao; Cao, Li

    2016-03-01

    Developmental dysplasia of the hip (DDH) is widespread in developing countries, and treating Crowe IV-Hartofilakidis Type III DDH in adults requires the use of a highly demanding technique. We sought to determine the outcome of cementless total hip arthroplasty using Zweymüller components to treat Crowe IV-Hartofilakidis Type III DDH. Fifty-eight patients (71 hips) with a mean age of 35.8 years at time of index operation were included in our study. The average duration of follow-up was 70.5 months. The acetabular component was placed in the true acetabulum in all cases, and subtrochanteric shortening osteotomy was performed in 61 hips. With any component revision for any reason as the end point, Kaplan-Meier survivorship analysis at 98 months revealed a cumulative survival rate for implanted components of 91.40%. The mean Harris Hip Score improved from 35.6 preoperatively to 82.9 postoperatively. There were 20 cases of intraoperative fracture, 1 case of complete nerve palsy, and 7 cases of transient nerve palsy. Revision surgery was performed in 7 patients because of cup loosening in 1, severe polyethylene wear in 4, cup breakage in 1, and dislocation in 1. Midterm results for cementless total hip arthroplasty in patients with Crowe IV-Hartofilakidis Type III DDH was satisfactory; however, intraoperative fracture and polyethylene wear were major complications. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Late-presenting developmental dysplasia of the hip in Jordanian males

    PubMed Central

    Samarah, Omar Q.; Hadidi, Fadi A. Al; Hamdan, Mohammad Q.; Hantouly, Ashraf T.

    2016-01-01

    Objectives: To describe the pattern of developmental dysplasia of the hip (DDH) in late presenting Jordanian male patients and identify the risk factors and associated findings. Methods: This is a retrospective study of 1145 male patients who attended the Pediatric Orthopedic Clinic for a DDH check up. This study was carried out in the Orthopedic Section, Special Surgery Department, Faculty of Medicine, The University of Jordan, Amman, Jordan between March 2011 and October 2014. Data was collected from medical records, and x-ray measurements were evaluated. Results: Of the 1145 male patients, 43 (3.75%) with 70 involved hips were diagnosed with late- presenting DDH. Being a first-born baby resulted in 41.9% increased risk for DDH. Cesarian delivery was significantly associated with an increased risk of hip dislocation (p=0.004) while normal delivery was significantly associated with acetabular dysplasia (p=0.004). No predictable risk factors were found in 44.2% patients with DDH. Bilateral cases were more common than unilateral cases: (26 [60.5%] versus 17 [39.5%]). Limited abduction was a constant finding in all dislocated hips (p<0.001). Associated conditions, such as club foot and congenital muscular torticollis were not observed. Conclusion: Cesarian section is a significant risk for dislocated hips while normal delivery is significantly associated with acetabular dysplasia. Bilateral DDH is more common than the unilateral. Club foot and torticollis were not observed in this series. PMID:26837397

  15. Osteochondral Autograft from the Ipsilateral Femoral Head by Surgical Dislocation for Treatment of Femoral Head Fracture Dislocation: A Case Report.

    PubMed

    Won, Yougun; Lee, Gi Soo; Kim, Sang Bum; Kim, Sun Joong; Yang, Kyu Hyun

    2016-11-01

    As anatomical reduction of the articular surface of femoral head fractures and restoration of damaged cartilage are essential for good long-term results, many treatment options have been suggested, including fixation of the fracture using various surgical exposures and implants, as well as arthroscopic irrigation and debridement, bone marrow stimulating techniques, osteochondral allograft, autograft, and autogenous chondrocyte implantation. We report a case of osteochondral autograft harvested from its own femoral articular surface through surgical hip dislocation. The osteochondral graft was harvested from the inferior non-weight-bearing articular surface and grafted to the osteochondral defect. One year later, the clinical and radiological results were good, without the collapse of the femoral head or arthritic change. This procedure introduced in our case is considered convenient and able to lessen surgical time without morbidity of the donor site associated with the harvest.

  16. Hip fracture after hemiplegia.

    PubMed Central

    Mulley, G.; Espley, A. J.

    1979-01-01

    In a series of 57 hemiplegic patients who subsequently fractured their hips, it was found that hip fracture occurred significantly more often on the hemiplegic side. Hip fracture was equally common in right- and left-sided hemiplegia, and often occurred within one year of the stroke. Two factors seem to be important in the genesis of hip fractures in hemiplegic patients: the tendency of stroke patients to fall to the affected side as a result of impaired locomotor function, and the development of disuse osteoporosis in the hemiplegic limb. PMID:471862

  17. Mobility Laws in Dislocation Dynamics Simulations

    SciTech Connect

    Cai, W; Bulatov, V V

    2003-10-21

    Prediction of the plastic deformation behavior of single crystals based on the collective dynamics of dislocations has been a challenge for computational materials science for a number of years. The difficulty lies in the inability of existing dislocation dynamics (DD) codes to handle a sufficiently large number of dislocation lines, to establish a statistically representative model of crystal plasticity. A new massively-parallel DD code is developed that is capable of modeling million-dislocation systems by employing thousands of processors. We discuss an important ingredient of this code--the mobility laws dictating the behavior of individual dislocations. They are materials input for DD simulations and are constructed based on the understanding of dislocation motion at the atomistic level.

  18. Effects of dislocations on electron channeling.

    PubMed

    George, Juby; Pathak, A P

    2009-02-18

    The phenomenon of electron channeling in a crystal affected by dislocations is considered. Earlier we had considered the quantum aspects of the positron channeling in a crystal bent by dislocations where the effects of longitudinal motion of the particle were also considered along with the transverse motion. In this paper, the effective potential for the electron case is found for the two regions of dislocation-affected channel. There is considerable shift in the potential minima due to dislocations. The frequency and the corresponding spectrum of the channeling radiation due to electrons channeling through the perfect channel and the two regions of dislocation-affected channels are calculated. The spectral distribution of radiation intensity changes with the parameters of dislocation. The continuity of wavefunctions and their derivatives is used at the three boundaries and the reflection and transmission coefficients are found using these boundary conditions in the same way as in the positron case.

  19. Transient Synovitis of the Hip

    MedlinePlus

    ... inflammation and swelling of the tissues around the hip joint. Usually only one hip is affected. This condition ... to reduce the swelling and inflammation around the hip joint.Your child's doctor will probably ask you to ...

  20. Worker Dislocation. Case Studies of Causes and Cures.

    ERIC Educational Resources Information Center

    Cook, Robert F., Ed.

    Case studies were made of the following dislocated worker programs: Cummins Engine Company Dislocated Worker Project; GM-UAW Metropolitan Pontiac Retraining and Employment Program; Minnesota Iron Range Dislocated Worker Project; Missouri Dislocated Worker Program Job Search Assistance, Inc.; Hillsborough, North Carolina, Dislocated Worker Project;…

  1. Elbow dislocation with ipsilateral distal radius fracture

    PubMed Central

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-01-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer. PMID:24082758

  2. Elbow dislocation with ipsilateral distal radius fracture.

    PubMed

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-07-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer.

  3. Enabling Strain Hardening Simulations with Dislocation Dynamics

    SciTech Connect

    Arsenlis, A; Cai, W

    2006-12-20

    Numerical algorithms for discrete dislocation dynamics simulations are investigated for the purpose of enabling strain hardening simulations of single crystals on massively parallel computers. The algorithms investigated include the /(N) calculation of forces, the equations of motion, time integration, adaptive mesh refinement, the treatment of dislocation core reactions, and the dynamic distribution of work on parallel computers. A simulation integrating all of these algorithmic elements using the Parallel Dislocation Simulator (ParaDiS) code is performed to understand their behavior in concert, and evaluate the overall numerical performance of dislocation dynamics simulations and their ability to accumulate percents of plastic strain.

  4. Congenital dislocation of the patella - clinical case.

    PubMed

    Miguel Sá, Pedro; Raposo, Filipa; Santos Carvalho, Manuel; Alegrete, Nuno; Coutinho, Jorge; Costa, Gilberto

    2016-01-01

    Congenital patellar dislocation is a rare condition in which the patella is permanently dislocated and cannot be reduced manually. The patella develops normally as a sesamoid bone of the femur. This congenital dislocation results from failure of the internal rotation of the myotome that forms the femur, quadriceps muscle and extensor apparatus. It usually manifests immediately after birth, although in some rare cases, the diagnosis may be delayed until adolescence or adulthood. Early diagnosis is important, thereby allowing surgical correction and avoiding late sequelae, including early degenerative changes in the knee. A case of permanent dislocation of the patella is presented here, in a female child aged seven years.

  5. Microdiffraction Analysis of Hierarchical Dislocation Organization

    SciTech Connect

    Barabash, R.I.; Ice, G.E.

    2007-12-19

    This article describes how x-ray microdiffraction is influenced by the number, kind, and organization of dislocations. Particular attention is placed on micro-Laue diffraction, where polychromatic x-rays are diffracted into characteristic Laue patterns that are sensitive to the dislocation content and arrangement. Diffraction is considered for various stages of plastic deformation. For early stages of plastic deformation with random dislocation spacing, the intensity in reciprocal space is redistributed about Laue spots with a length scale proportional to the number of dislocations within the sample volume and with a characteristic shape that depends on the kinds of dislocations and the momentum transfer vector. Unpaired dislocations that contribute to lattice rotations cause the largest redistribution of scattered intensity. In later stages of plastic deformation, strong interactions between individual dislocations cause them to organize into correlated arrangements. Here again, xray diffraction Laue spots are broadened in proportion to the number of excess (unpaired) dislocations inside the wall and to the total number of unpaired walls, but the broadening can be discontinuous. With microdiffraction it is possible to quantitatively test models of dislocation organization.

  6. Massively-Parallel Dislocation Dynamics Simulations

    SciTech Connect

    Cai, W; Bulatov, V V; Pierce, T G; Hiratani, M; Rhee, M; Bartelt, M; Tang, M

    2003-06-18

    Prediction of the plastic strength of single crystals based on the collective dynamics of dislocations has been a challenge for computational materials science for a number of years. The difficulty lies in the inability of the existing dislocation dynamics (DD) codes to handle a sufficiently large number of dislocation lines, in order to be statistically representative and to reproduce experimentally observed microstructures. A new massively-parallel DD code is developed that is capable of modeling million-dislocation systems by employing thousands of processors. We discuss the general aspects of this code that make such large scale simulations possible, as well as a few initial simulation results.

  7. Hip pathology in Majewski osteodysplastic primordial dwarfism type II.

    PubMed

    Karatas, Ali F; Bober, Michael B; Rogers, Kenneth; Duker, Angela L; Ditro, Colleen P; Mackenzie, William G

    2014-09-01

    Majewski osteodysplastic primordial dwarfism type II (MOPDII) is characterized by severe prenatal and postnatal growth failure with microcephaly, characteristic skeletal dysplasia, an increased risk for cerebrovascular disease, and insulin resistance. MOPDII is caused by mutations in the pericentrin (PCNT) gene and is inherited in an autosomal-recessive manner. This study aimed to determine the incidence of hip pathology in patients with molecularly confirmed MOPDII and to describe the functional outcomes of surgical treatment. Thirty-three enrolled patients had a clinical diagnosis of MOPDII. Biallelic PCNT mutations or absent pericentrin protein was confirmed in 25 of these patients. Twelve patients (7 female) had appropriate clinical and radiographic records at this institution and were included in this study. The data collected included age at presentation, age at surgery, sex, body weight and height, weight-bearing status at diagnosis, and the clinical examination. Four patients (31%) had coxa vara: 3 unilateral and 1 bilateral. Three unilateral patients had in situ pinning at a mean age 4 years. The patient with bilateral coxa vara had valgus osteotomy at the age of 5 years. Two children had bilateral hip dysplasia and subluxation with no surgery. One patient had bilateral developmental hip dislocations. The patient was treated by open reduction-spica cast and 2 years after surgery, coxa valga was noted. Another patient was diagnosed at an age of 12 years with bilateral avascular necrosis of the hips. Four patients did not have hip pathology. Hip pathology is common among children with MOPDII; coxa vara is the most frequent diagnosis. Routine clinical and radiographic hip evaluation is important. The capital femoral epiphysis appears to slip down along the shaft, giving the appearance of a proximal femoral epiphysiolysis. A hip diagnosed with slipped capital femoral epiphysis in early life may progress to severe coxa vara. Level IV.

  8. Multiscale modeling of dislocation-precipitate interactions in Fe: From molecular dynamics to discrete dislocations.

    PubMed

    Lehtinen, Arttu; Granberg, Fredric; Laurson, Lasse; Nordlund, Kai; Alava, Mikko J

    2016-01-01

    The stress-driven motion of dislocations in crystalline solids, and thus the ensuing plastic deformation process, is greatly influenced by the presence or absence of various pointlike defects such as precipitates or solute atoms. These defects act as obstacles for dislocation motion and hence affect the mechanical properties of the material. Here we combine molecular dynamics studies with three-dimensional discrete dislocation dynamics simulations in order to model the interaction between different kinds of precipitates and a 1/2〈111〉{110} edge dislocation in BCC iron. We have implemented immobile spherical precipitates into the ParaDis discrete dislocation dynamics code, with the dislocations interacting with the precipitates via a Gaussian potential, generating a normal force acting on the dislocation segments. The parameters used in the discrete dislocation dynamics simulations for the precipitate potential, the dislocation mobility, shear modulus, and dislocation core energy are obtained from molecular dynamics simulations. We compare the critical stresses needed to unpin the dislocation from the precipitate in molecular dynamics and discrete dislocation dynamics simulations in order to fit the two methods together and discuss the variety of the relevant pinning and depinning mechanisms.

  9. Total arthroplasty in displaced dysplastic hips with acetabular reconstruction and femoral shortening – technical note☆☆☆

    PubMed Central

    Silva, Paulo; de Oliveira, Leandro Alves; Coelho, Danilo Lopes; do Amaral, Rogério Andrade; Rebello, Percival Rosa; de Moraes, Frederico Barra

    2014-01-01

    To describe a new procedure of total hip replacement in patient with severe developmental dysplasia of the left hip, using technique of acetabular reconstruction with autogenous bone grafts and subtrochanteric shortening femoral osteotomy. Total hip replacement done in January of 2003. The Eftekhar's classification was used and included type D, neglected dislocations. Bone graft incorporated in acetabular shelf and femoral osteotomy. Our contribution is the use of an Allis plate to better fix acetabular grafts, avoiding loosening, and cerclage around bone graft in femoral osteotomy site, which diminish pseudoarthrosis risk. This technique shows efficiency, allowing immediately resolution for this case with pain and range of motion of hip improvement. It also allows the acetabular dysplasia reconstruction, equalization of the limb length (without elevated risk of neurovascular lesion) and repairs the normal hip biomechanics due to the correction of the hip's center of rotation. PMID:26229775

  10. Total Hip Arthroplasty for the Paralytic and Non-paralytic Side in Patient with Residual Poliomyelitis

    PubMed Central

    Sonohata, Motoki; Kitajima, Masaru; Kawano, Shunsuke; Mawatari, Masaaki

    2016-01-01

    Background: Total hip arthroplasty (THA) for poliomyelitis is a problematic procedure due to difficulty in positioning the cup of the prosthesis in the true acetabulum and the risk of dislocation after THA due to the low muscle tone. Methods: We herein present a case of bilateral hip pain with a history of poliomyelitis. Radiograph showed bilateral hip osteoarthritis caused by hip dysplasia due to residual poliomyelitis in right hip joint or developing dysplasia of the hip joint in left hip joint. THA was performed to bilateral hip joints. Results: Six years after bilateral THA, bilateral hip pain significantly improved. Additionally, the muscle strength on the paralyzed right side partially improved. However, the muscle strength on the non-paralyzed left side did not significantly improve. No complications related to the surgery were observed. Conclusion: Promising early results were obtained for THA in our patient with residual poliomyelitis. However, surgeons should pay attention to the potential development of complications concerning THA that may arise due to the residual poliomyelitis. PMID:27347238

  11. The influence of spine-hip relations on total hip replacement: A systematic review.

    PubMed

    Rivière, C; Lazennec, J-Y; Van Der Straeten, C; Auvinet, E; Cobb, J; Muirhead-Allwood, S

    2017-06-01

    Sagittal pelvic kinematics along with spino-pelvic angular parameters have recently been studied by numerous investigators for their effect on total hip replacement (THR) clinical outcomes, but many issue of spine-hip relations (SHR) are currently unexplored. Therefore, our review aims at clarifying the following questions: is there any evidence of a relationship between articular impingement/dislocation risk in primary THR and (1) certain sagittal pelvic kinematics patterns, (2) pelvic incidence, and (3) types of SHRs? A systematic review of the existing literature utilising PubMed and Google search engines was performed in January 2017. Only clinical or computational studies published in peer-reviewed journals over the last five years in either English or French were reviewed. We identified 769 reports, of which 12 met our eligibility criteria. A review of literature shows that sagittal pelvic kinematics, but not the pelvic incidence, influences the risk of prosthetic impingement/dislocation. We found no study having assessed the relationship between this risk and the types of SHRs. Sagittal pelvic kinematics is highly variable among individuals and certain kinematic patterns substantially influences the risk of prosthetic impingement/dislocation. Recommendations for cup positioning are therefore switching from a systematic to a patient-specific approach, with the standing cup orientation Lewinneck safe zone progressively giving way to a new parameter of interest: the functional orientation of the cup. Based on a recently published classification for SHRs, We propose a new concept of "kinematically aligned THR" for the purposes of THR planning. Further studies are needed to investigate the relevance of such a classification towards the assumptions and hypothesis we have made. Level of evidence,- Level IV, systematic review of level III and IV studies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Dislocations

    MedlinePlus

    ... sure kids wear the appropriate safety gear during sports activities. Supervise children when they're playing — a hard fall can happen anywhere, anytime. Avoid tugging hard on a young child's arm or shoulder, which can cause injury or ...

  13. Ceramic-on-ceramic THA associated with fewer dislocations and less muscle degeneration by preserving muscle progenitors.

    PubMed

    Hernigou, Philippe; Roussignol, Xavier; Delambre, Jerome; Poignard, Alexandre; Flouzat-Lachaniette, Charles-Henri

    2015-12-01

    Dislocation is a common complication after total hip arthroplasty (THA). Although the etiology of dislocation is multifactorial, longer-term changes in muscle such as atrophy may influence the risk of prosthetic dislocation. Biological differences in wear products generated by different bearing surfaces may influence differences in the appearance of periarticular muscle after THA; however, such bearing-associated differences to our knowledge have not been studied in vivo, and few studies have evaluated bearing-associated differences in dislocation risk. (1) Is there a correlation between the postoperative risk of dislocation at revision and the bearing surfaces of the primary arthroplasty? (2) Is there a higher extent of fatty muscle atrophy on CT scan in hips with osteolysis (polyethylene hips) as compared with hips without osteolysis (ceramic-on-ceramic hips)? (3) Are these two abnormalities (bone osteolysis and fatty atrophy) associated with a decrease of mesenchymal stem cells (MSCs) in bone and in muscle? We retrospectively evaluated 240 patients (240 hips) who had a THA revision (98% of which, 235 of the 240, were isolated acetabular revisions) and a normal contralateral hip. All patients had received the same implants for the primary arthroplasty (32-mm head) except for bearing surfaces (80 hips with ceramic-on-ceramic, 160 with polyethylene). No differences were noted between the groups in terms of age, sex, body mass index, proportion of patients who had a dislocation after the index arthroplasty but before the revision, and proportion of the patients with stem loosening in addition to acetabular loosening. Indications for revision generally were cup loosening. The revisions in the hips with polyethylene bearings generally had more acetabular bone loss, but the position of the center of the cup and the orientation of the cup were similar after reconstruction in the two groups. Before revision, osteolysis, muscle atrophy, and fatty degeneration were

  14. Quantum dislocations in solid Helium-4

    NASA Astrophysics Data System (ADS)

    Aleinikava, Darya

    In this thesis the following problems on properties of solid 4He are considered: (i) the role of long-range interactions in suppression of dislocation roughening at T = 0; (ii) the combined effect of 3He impurities and Peierls potential on shear modulus softening; (iii) the dislocation superclimb and its connection to the phenomenon of "giant isochoric compressibility"; (iv) non-linear dislocation response to the applied stress and stress-induces dislocation roughening as a I-order phase transition in 1D at finite temperature. First we investigate the effect of long-range interactions on the state of edge dislocation at T = 0. Such interactions are induced by elastic forces of the solid. We found that quantum roughening transition of a dislocation at T = 0 is completely suppressed by arbitrarily small long-range interactions between kinks. A heuristic argument is presented and the result has been verified by numerical Monte-Carlo simulations using Worm Algorithm in J-current model. It was shown that the Peierls potential plays a crucial role in explaining the elastic properties of dislocations, namely shear modulus softening phenomenon. The crossover from T = 0 to finite temperatures leads to intrinsic softening of the shear modulus and is solely controlled by kink typical energy. It was demonstrated that the mechanism, involving only the binding of 3He impurities to the dislocations, requires an unrealistically high concentrations of defects (or impurities) in order to explain the shear modulus phenomenon and therefore an inclusion of Peierls potential in consideration is required. Superclimbing dislocations, that is the edge dislocations with the superfluidity along the core, were investigated. The theoretical prediction that superclimb is responsible for the phenomenon of "giant isochoric compressibility" was confirmed by Monte-Carlo simulations. It was demonstrated that the isochoric compressibility is suppressed at low temperatures. The dependence of

  15. Formed HIP Can Processing

    SciTech Connect

    Clarke, Kester Diederik

    2015-07-27

    The intent of this report is to document a procedure used at LANL for HIP bonding aluminum cladding to U-10Mo fuel foils using a formed HIP can for the Domestic Reactor Conversion program in the NNSA Office of Material, Management and Minimization, and provide some details that may not have been published elsewhere. The HIP process is based on the procedures that have been used to develop the formed HIP can process, including the baseline process developed at Idaho National Laboratory (INL). The HIP bonding cladding process development is summarized in the listed references. Further iterations with Babcock & Wilcox (B&W) to refine the process to meet production and facility requirements is expected.

  16. Surgical results of developmental dysplasia of the hip in older children based on using three-dimensional computed tomography.

    PubMed

    Zhao, Xiong; Yan, Ya-Bo; Cao, Peng-Chong; Ma, Yi-Shan; Wu, Zi-Xiang; Zhang, Yang; Zang, Yuan; Jie, Qiang; Lei, Wei

    2014-06-15

    The surgical management of developmental dysplasia of the hip (DDH) in older children has been the subject of controversy. The purpose of this study was to evaluate the outcome in patients with neglected DDH who underwent individual procedures based on using three-dimensional computed tomography. Forty-seven patients (59 hips) were treated using Pemberton osteotomy or Dega plus Pemberton osteotomy. Subtrochanteric transverse femoral shortening and derotation osteotomy were performed for all patients. The average age at the time of surgery was 10.5 y for group 1 (bilateral dislocation, 24 hips) and 11.2 y for group 2 (unilateral dislocation, 35 hips). Mean follow-up was 5.3 y for group 1 and 5.8 y for group 2. At the end of follow-up, 13 hips (54.2%) were rated excellent, eight hips (33.3%) were good, and three hips (12.5%) were fair in group 1. In group 2, 20 hips (57.1%) were rated excellent, 10 hips (28.6%) were good, and five hips (14.3%) were fair. There were five patients who had a limb length discrepancy of approximately 1.5 cm in group 2. Six hips in group 1 and seven hips in group 2 had osteonecrosis of varying severity. We believe that preoperation three-dimensional computed tomography evaluation, personalized operation plans, and experience with the surgical procedure are the main reasons for the satisfactory therapeutic effects achieved in this study in older children with DDH. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Dislocated interests and climate change

    NASA Astrophysics Data System (ADS)

    Davis, Steven J.; Diffenbaugh, Noah

    2016-06-01

    The predicted effects of climate change on surface temperatures are now emergent and quantifiable. The recent letter by Hansen and Sato (2016 Environ. Res. Lett. 11 034009) adds to a growing number of studies showing that warming over the past four decades has shifted the distribution of temperatures higher almost everywhere, with the largest relative effects on summer temperatures in developing regions such as Africa, South America, southeast Asia, and the Middle East (e.g., Diffenbaugh and Scherer 2011 Clim. Change 107 615-24 Anderson 2011 Clim. Change 108 581; Mahlstein et al 2012 Geophys. Res. Lett. 39 L21711). Hansen and Sato emphasize that although these regions are warming disproportionately, their role in causing climate change—measured by cumulative historical CO2 emissions produced—is small compared to the US and Europe, where the relative change in temperatures has been less. This spatial and temporal mismatch of climate change impacts and the burning of fossil fuels is a critical dislocation of interests that, as the authors note, has ‘substantial implications for global energy and climate policies.’ Here, we place Hansen and Sato’s ‘national responsibilities’ into a broader conceptual framework of problematically dislocated interests, and briefly discuss the related challenges for global climate mitigation efforts.

  18. A Perspective on Dislocation Dynamics

    NASA Astrophysics Data System (ADS)

    Ghoniem, Nasr M.

    A fundamental description of plastic deformation has been recently pursued in many parts of the world as a result of dissatisfaction with the limitations of continuum plasticity theory. Although continuum models of plastic deformation are extensively used in engineering practice, their range of application is limited by the underlying database. The reliability of continuum plasticity descriptions is dependent on the accuracy and range of available experimental data. Under complex loading situations, however, the database is often hard to establish. Moreover, the lack of a characteristic length scale in continuum plasticity makes it difficult to predict the occurrence of critical localized deformation zones. Although homogenization methods have played a significant role in determining the elastic properties of new materials from their constituents (e.g., composite materials), the same methods have failed to describe plasticity. It is widely appreciated that plastic strain is fundamentally heterogenous, displaying high strains concentrated in small material volumes, with virtually undeformed regions in-between. Experimental observations consistently show that plastic deformation is heterogeneous at all length-scales. Depending on the deformation mode, heterogeneous dislocation structures appear with definitive wavelengths. A satisfactory description of realistic dislocation patterning and strain localization has been rather elusive. Attempts aimed at this question have been based on statistical mechanics, reaction-diffusion dynamics, or the theory of phase transitions. Much of the efforts have aimed at clarifying the fundamental origins of inhomogeneous plastic deformation. On the other hand, engineering descriptions of plasticity have relied on experimentally verified constitutive equations.

  19. Results of Charnley total hip arthroplasty at a minimum of thirty years. A concise follow-up of a previous report.

    PubMed

    Callaghan, John J; Templeton, Jesse E; Liu, Steve S; Pedersen, Douglas R; Goetz, Devon D; Sullivan, Patrick M; Johnston, Richard C

    2004-04-01

    The purpose of the current study was to update the results of a prospective, single-surgeon series of primary Charnley total hip arthroplasties performed with cement. This investigation is one of the first studies in which hips treated with total hip arthroplasty with cement were followed for a minimum of thirty years. Twenty-seven patients (thirty-four [10.3%] of the hips in the initial study group) were alive at a minimum of thirty years postoperatively. These patients served as the focus of the present study. Revision because of aseptic loosening of the acetabular component was performed in 7.3% (twenty-three) of the hips from the original study group (excluding those revised because of infection or dislocation) and 26% (eight) of the hips in the living cohort. Revision because of aseptic loosening of the femoral component was performed in 3.2% (ten) of the hips from the original study group (excluding those revised because of infection or dislocation) and 10% (three) of the hips in the living patients. Since the twenty-five-year review, three hips were revised (one because of acetabular loosening, one because of femoral loosening, and one because of instability). This end-result study demonstrated the remarkable durability of cemented Charnley total hip replacements over a span of three decades, with 88% of the original prostheses intact at the time of the final follow-up or at the patient's death.

  20. [Hip dysplasia in adolescence].

    PubMed

    Barthès, X; Seringe, R

    1995-01-01

    Hip growth continues on till adolescence with the fusion of the different ossification centers. Does this growth exist in hip dysplasia? What is the role of surgery at adolescence? Is an additional varus osteotomy indicated with a pelvic osteotomy? Clinical and radiological criteria of adolescent hip dysplasia were studied in a series of 18 patients (mean age 12 years). The 28 hips were divided into 4 groups depending on the treatment: non operated hips (group 1, N = 8), hips operated on only by pelvic osteotomy (group 2, N = 8), hips operated on by combined pelvic and femoral osteotomies (group 3, N = 9), and hips operated on only by femoral osteotomy (group 4, N = 3). Tonnis's clinical criteria were used. The acetabular index of the weight bearing zone, the center-edge angle of Wiberg, the acetabular angle of Idelberger and Frank, the neck-shaft angle, the head coverage index were measured and compared between the 4 groups (average follow-up was 46 months). We noted continuation of growth of the acetabulum at adolescence with a correction of moderate hip dysplasia when the head was covered (group 1), the acetabular index of the weight-bearing zone decreased from 20.1 degrees to 11.1 degrees; the center-edge angle of Wiberg increased from 15.25 degrees to 23 degrees. The comparison of groups 2 and 3 showed that an additional femoral osteotomy does not change significantly the radiologic results. Does surgery benefit at adolescence from the growth which exists during this period? The clinical results and the evolution of arthrosis following a Chiari pelvic osteotomy are better when the operation is performed early. A pelvic osteotomy is indicated in symptomatic hips, when the congruity is abnormal, with deficient head coverage, as well as moderate dysplasia when the evolution of the acetabular parameters are not satisfactory. A femoral osteotomy in addition to a pelvic osteotomy does not seem justified.

  1. Tomographic index as auxiliary criteria for surgery indication in fracture dislocation of acetabulum posterior wall

    PubMed Central

    2012-01-01

    There are situations which the tomographic exam is done on the affected hip or situations where the contralateral hip presents abnormalities that make it impossible to compare. In this study we aimed to evaluate a tomographic index that does not require comparison between the both hips. Twenty two patients with unilateral acetabular fracture dislocation with fracture of posterior wall were studied. We established the relationship between the remaining posterior wall and the femoral head diameter (head/wall index-H/W index). We evaluated 45 two-dimensional computed tomography scan in normal hips and established the H/W index. In 45 normal hips we simulated a posterior wall fracture with involvement of 25% and 30% of the posterior wall and calculated the H/W index. We divided into five groups with five different H/W index (fractured group with non surgical treatment; fractured group; normal group; normal group with simulated fracture of 25% and; 30% of the posterior wall). 2.4 was the lowest limit of confidence interval of the group with 25% of the posterior wall fracture. When we analyzed the confidence interval of the 30% fracture group the upper limit of the confidence interval was 2.7, close to the lower limit of the surgical group that was 2.9. Thus, we suggest the 2.4 the H/W index limit as an auxiliary criteria to indicate whether or not to operate. H/W index is helpful to decide whether or not surgery indication in the fracture dislocation of the posterior wall of the acetabulum. PMID:22715811

  2. Large diameter metal on metal total hip replacement for femoral neck fractures with neurological conditions

    PubMed Central

    Li, Jia; Zheng, Wei; Zhao, Jinzhu; Liu, Denghui; Xu, Weidong

    2014-01-01

    Background: Patients with Parkinson's disease and poliomyelitis can have a femoral neck fracture; yet, the optimal methods of treatment for these hips remains controversial. Many constrained or semi-constrained prostheses, using constrained liners (CLs) with a locking mechanism to capture the femoral head, were used to treat femoral neck fractures in patients with neurological disorders. We retrospectively studied a group of patients with Parkinson's disease and poliomyelitis who sustained femoral neck fractures and were treated by total hip arthroplasty using an L-MoM prosthesis. Materials and Methods: We retrospectively reviewed 12 hips in 12 patients who underwent large-diameter metal-on-metal (L-MoM) total hip replacement between May 2007 and October 2009. Eight of the 12 patients (8 hips; 66.7%) had Parkinson's disease and 4 patients (4 hips; 33.3%) were affected with poliomyelitis. Results: The followup time was 5.2 years (range 3.6-6.0 years). At the latest followup, all the patients showed satisfactory clinical and radiographic results, with pain relief. No complications, such as dislocation or aseptic loosening occurred. Conclusion: We believe the use of L-MoM can diminish the rate of instability or dislocation, after operation. The L-MoM is an option for patients with Parkinson's disease and poliomyelitis with femoral neck fracture. PMID:25404774

  3. Fast Fourier transform discrete dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Graham, J. T.; Rollett, A. D.; LeSar, R.

    2016-12-01

    Discrete dislocation dynamics simulations have been generally limited to modeling systems described by isotropic elasticity. Effects of anisotropy on dislocation interactions, which can be quite large, have generally been ignored because of the computational expense involved when including anisotropic elasticity. We present a different formalism of dislocation dynamics in which the dislocations are represented by the deformation tensor, which is a direct measure of the slip in the lattice caused by the dislocations and can be considered as an eigenstrain. The stresses arising from the dislocations are calculated with a fast Fourier transform (FFT) method, from which the forces are determined and the equations of motion are solved. Use of the FFTs means that the stress field is only available at the grid points, which requires some adjustments/regularizations to be made to the representation of the dislocations and the calculation of the force on individual segments, as is discussed hereinafter. A notable advantage of this approach is that there is no computational penalty for including anisotropic elasticity. We review the method and apply it in a simple dislocation dynamics calculation.

  4. Dislocation generation during early stage sintering.

    NASA Technical Reports Server (NTRS)

    Sheehan, J. E.; Lenel, F. V.; Ansell, G. S.

    1973-01-01

    Discussion of the effects of capillarity-induced stresses on dislocations during early stage sintering. A special version of Hirth's (1963) theoretical calculation procedures modified to describe dislocation nucleation on planes meeting the sintering body's neck surface obliquely is shown to predict plastic flow at stress levels know to exist between micron size metal particles in the early stages of sintering.

  5. Statistics of dislocation pinning at localized obstacles

    SciTech Connect

    Dutta, A.; Bhattacharya, M. Barat, P.

    2014-10-14

    Pinning of dislocations at nanosized obstacles like precipitates, voids, and bubbles is a crucial mechanism in the context of phenomena like hardening and creep. The interaction between such an obstacle and a dislocation is often studied at fundamental level by means of analytical tools, atomistic simulations, and finite element methods. Nevertheless, the information extracted from such studies cannot be utilized to its maximum extent on account of insufficient information about the underlying statistics of this process comprising a large number of dislocations and obstacles in a system. Here, we propose a new statistical approach, where the statistics of pinning of dislocations by idealized spherical obstacles is explored by taking into account the generalized size-distribution of the obstacles along with the dislocation density within a three-dimensional framework. Starting with a minimal set of material parameters, the framework employs the method of geometrical statistics with a few simple assumptions compatible with the real physical scenario. The application of this approach, in combination with the knowledge of fundamental dislocation-obstacle interactions, has successfully been demonstrated for dislocation pinning at nanovoids in neutron irradiated type 316-stainless steel in regard to the non-conservative motion of dislocations. An interesting phenomenon of transition from rare pinning to multiple pinning regimes with increasing irradiation temperature is revealed.

  6. Palmar dislocation of scaphoid and lunate.

    PubMed

    Idrissi, Khalid Koulali; Galiua, Farid

    2011-09-28

    A palmar dislocation of scaphoid and lunate is uncommon. We have found only 19 reported cases in the literature. We reported a simultaneous, divergent dislocation. The closed reduction followed by percutaneous pinning has given a good result without avascular necrosis of any carpal bone.

  7. Posterior dislocation of the shoulder in athletes.

    PubMed

    Samilson, R L; Prieto, V

    1983-07-01

    Although posterior dislocation of the shoulder is a rare injury in athletes, failure to recognize and properly manage acute dislocation may have serious consequences. The article discusses the incidence, mechanism of injury, classification, pathologic findings, clinical and radiologic diagnosis, and management.

  8. [Revision total hip arthroplasty using a cementless prosthesis].

    PubMed

    Jiang, Qing; Xu, Zhi-hong; Chen, Dong-yang; Shi, Dong-quan; Qin, Jiang-hui; Dai, Jin; Weng, Wen-jie; Yuan, Tao

    2012-05-01

    To assess the operative technique and results with the usage of cementless prosthesis in hip revision. Retrospective study was done on revision of total hip arthroplasty with cementless prosthesis in 72 patients (41 males and 31 females) with an average age of 65.7 years (28-82 years) from January 2004 to December 2009. The reason for revision was 2 infection, 54 aseptic loosening, 4 periprosthetic fractures, 5 fracture of femoral stems and 7 cases of acetabular abrasion after hemi-arthroplasty. The operation time, bleeding loss, complications of infection, dislocation, periprosthetic fractures and loosening were evaluated. The Harris score were used for hip function evaluation. The average operation time was (146±47) minutes (70-280 minutes) and bleeding loss during the operation was (970±540) ml (200-2500 ml). Bacterium cultivation during operation demonstrated infection in 2 patients. Bone windows at the lateral femoral were opened in 4 patients and extend trochanteric osteotomy was done in 7 patients. Fracture of the proximal femur occurred in 8 cases. Twenty-nine patients were treated with bone graft including 18 autografts and 11 allografts. Sixty-seven patients were followed up for an average time of 66 months (20-92 months). Additional revisions were performed in 3 cases including 2 dislocations and 1 infection. There were no death, no damage of major blood vessels and nerves. The bone graft healed during 3-5 months. The survival rates of the femoral prosthesis and the acetabulum prostheses were 95.5% and 98.4%. The mean Harris score was 86±8 (55-95 points). Osteolysis were seen in 13 hips but migration was seen in only 1 patient. The cementless prosthesis is useful in revision total hip arthroplasty and the perfect clinical results are related to the reliable primary fixation.

  9. Use of ceramics in total hip replacement.

    PubMed

    Lang, Jason E; Whiddon, David R; Smith, Eric L; Salyapongse, Aaron K

    2008-01-01

    Ceramics have been used as a bearing surface in total hip arthroplasty (THA) for more than 30 years. Properties of this material which make it particularly attractive for this application include its hardness, high compression strength, and excellent wettability. The low incidence of biologically significant particle generation and clinically significant osteolysis with the use of ceramics in THA reflects these properties. However, low fracture toughness and linear elastic behavior demonstrated by ceramic make it prone to breakage under stress. Improvements in the processing of ceramic as well as advances in engineering of head-neck articulations and liner design have led to an overall decrease in the incidence of ceramic fracture and dislocation. This article reviews the science behind the use of ceramics in THA, the clinical results of ceramics in THA, including complications unique to this bearing surface, and future directions for the application of ceramics in THA.

  10. Characterization of Geometrically Necessary Dislocation Content with EBSD-Based Continuum Dislocation Microscopy

    NASA Astrophysics Data System (ADS)

    Ruggles, Timothy J.

    Modeling of plasticity is often hampered by the difficulty in accurately characterizing dislocation density on the microscale for real samples. It is particularly difficult to resolve measured dislocation content onto individual dislocation systems at the length scales most commonly of interest in plasticity studies. Traditionally, dislocation content is analyzed at the continuum level using the Nye tensor and the fundamental relation of continuum dislocation theory to interpret information measured by diffraction techniques, typically EBSD or High Resolution EBSD. In this work the established Nye-Kroner method for resolving measured geometrically necessary dislocation content onto individual slip systems is assessed and extended. Two new methods are also presented to relieve the ambiguity of the Nye-Kroner method. One of these methods uses modified classical dislocation equations to bypass the Nye-Kroner relation, and the other estimates the bulk dislocation density via the entry-wise one-norm of the Nye tensor. These methods are validated via a novel simulation of distortion fields around continuum fields of dislocation density based on classical lattice mechanics and then applied to actual HR-EBSD scans of a micro-indented single crystals of nickel and tantalum. Finally, a detailed analysis of the effect of the spacing between points in an EBSD scan (which is related to the step size of the numerical derivatives used in EBSD dislocation microscopy) on geometrically necessary dislocation measurements is conducted.

  11. Initial dislocation structure and dynamic dislocation multiplication in Mo single crystals

    SciTech Connect

    Hsiung, L M; Lassila, D H

    2000-03-22

    Initial dislocation structure in annealed high-purity Mo single crystals and deformation substructure in a crystal subjected to 1% compression have been examined and studied in order to investigate dislocation multiplication mechanisms in the early stages of plastic deformation. The initial dislocation density is in a range of 10{sup 6} {approx} 10{sup 7} cm{sup -2}, and the dislocation structure is found to contain many grown-in superjogs along dislocation lines. The dislocation density increases to a range of 10{sup 8} {approx} 10{sup 9} cm{sup -2}, and the average jog height is also found to increase after compressing for a total strain of 1%. It is proposed that the preexisting jogged screw dislocations can act as (multiple) dislocation multiplication sources when deformed under quasi-static conditions. Both the jog height and length of link segment (between jogs) can increase by stress-induced jog coalescence, which takes place via the lateral migration (drift) of superjogs driven by unbalanced line-tension partials acting on link segments of unequal lengths. Applied shear stress begins to push each link segment to precede dislocation multiplication when link length and jog height are greater than critical lengths. This dynamic dislocation multiplication source is subsequently verified by direct simulations of dislocation dynamics under stress to be crucial in the early stages of plastic deformation in Mo single crystals.

  12. Current Concepts in Hip Preservation Surgery: Part II--Rehabilitation.

    PubMed

    Adler, Kelly L; Cook, P Christopher; Geisler, Paul R; Yen, Yi-Meng; Giordano, Brian D

    2016-01-01

    Successful treatment of nonarthritic hip pain in young athletic individuals remains a challenge. A growing fund of clinical knowledge has paralleled technical innovations that have enabled hip preservation surgeons to address a multitude of structural variations of the proximal femur and acetabulum and concomitant intra-articular joint pathology. Often, a combination of open and arthroscopic techniques are necessary to treat more complex pathomorphologies. Peri- and postoperative recovery after such procedures can pose a substantial challenge to the patient, and a dedicated, thoughtful approach may reduce setbacks, limit morbidity, and help optimize functional outcomes. PubMed and CINAHL databases were searched to identify relevant scientific and review articles through December 2014 using the search terms hip preservation, labrum, surgical dislocation, femoroacetabular impingement, postoperative rehabilitation, peri-acetabular osteotomy, and rotational osteotomy. Reference lists of included articles were reviewed to locate additional references of interest. Clinical review. Level 4. Hip preservation procedures and appropriate rehabilitation have allowed individuals to return to a physically active lifestyle. Effective postoperative rehabilitation must consider modifications and precautions specific to the particular surgical techniques used. Proper postoperative rehabilitation after hip preservation surgery may help optimize functional recovery and maximize clinical success and patient satisfaction. © 2015 The Author(s).

  13. Hip salvage surgery in cerebral palsy cases: a systematic review.

    PubMed

    de Souza, Rafael Carboni; Mansano, Marcelo Valentim; Bovo, Miguel; Yamada, Helder Henzo; Rancan, Daniela Regina; Fucs, Patricia Maria de Moraes Barros; Svartman, Celso; de Assumpção, Rodrigo Montezuma César

    2015-01-01

    Imbalance and muscle spasticity, in association with coxa valga and persistent femoral anteversion, compromises hip development in cases of cerebral palsy and may result in chronic pain and even dislocation. Some of these hips undergo salvage surgery because of the severe impact of their abnormalities in these patients' quality of life. We conducted a systematic review of the literature to compare the results from the main hip salvage techniques applied to these individuals. The literature search focused on studies that evaluated results from hip salvage surgery in cases of cerebral palsy, published from 1970 to 2011, which are present in the Embase, Medline, PubMed, Cochrane Library and SciELO databases. Although the results were not statistically comparable, this systematic review demonstrates that hip salvage surgery should be indicated after individual evaluation on each patient, due to the wide spectrum of presentations of cerebral palsy. Therefore, it seems that no surgical technique is superior to any other. Rather, there are different indications.

  14. Glide dislocation nucleation from dislocation nodes at semi-coherent {111} Cu–Ni interfaces

    SciTech Connect

    Shao, Shuai; Wang, Jian; Beyerlein, Irene J.; Misra, Amit

    2015-07-23

    Using atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, we show that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. We identified four distinctive node structures: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu–Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces. Finally, under biaxial tension/compression applied parallel to the interface, we show that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.

  15. Glide dislocation nucleation from dislocation nodes at semi-coherent {111} Cu–Ni interfaces

    DOE PAGES

    Shao, Shuai; Wang, Jian; Beyerlein, Irene J.; ...

    2015-07-23

    Using atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, we show that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. We identified four distinctive node structures: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu–Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces.more » Finally, under biaxial tension/compression applied parallel to the interface, we show that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.« less

  16. Acute traumatic posterior elbow dislocation in children.

    PubMed

    Lieber, Justus; Zundel, Sabine M; Luithle, Tobias; Fuchs, Jörg; Kirschner, Hans-Joachim

    2012-09-01

    Traumatic posterior dislocation of the elbow is often associated with significant morbidity and incomplete recovery. The aim of this study was to retrospectively analyse the outcome of 33 children (median age 10.8 years). Patients underwent reduction and assessment of stability under general anaesthesia. Pure dislocations (n=10) were immobilized, whereas unstable fractures (n=23) were stabilized. Refixation of ligaments was performed if stability was not achieved by fracture stabilization alone. Immobilization was continued for 26 (pure dislocations) or 35 days (associated injuries), respectively. Results were excellent (n=9) or good (n=1) after pure dislocation. Results were excellent (n=15), good (n=7) or poor (n=1) in children with associated injuries. Accurate diagnosis, concentric stable reduction of the elbow as well as stable osteosynthesis of displaced fractures are associated with good results in children with acute posterior elbow dislocations.

  17. Bipolar dislocation of the forearm (floating forearm).

    PubMed

    Aşkar, Hüseyin; Ertürk, Cemil; Altay, Mehmet Akif; Akif Altay, Mehmet; Bilge, Ali

    2014-01-01

    Bipolar dislocation of the forearm (floating forearm) is an unusual injury and is therefore often overlooked. We report a 28-year-old male patient who presented at another center with a history of a fall while climbing a tree. The patient's left elbow was treated with closed reduction and immobilization with a long-arm cast brace due to elbow dislocation. However, the patient was admitted with pain and swelling of the wrist to our emergency department the following day. Physical and radiological examination revealed dorsal trans-scaphoid perilunate dislocation. A dorsal incision was performed for open reduction and internal fixation to provide wide surgical exposure. Concomitant occurrence of elbow dislocation and fracture-dislocation of the perilunate is infrequent. Therefore, physicians should be aware of possible additional injuries and current recommended treatment methods.

  18. Dislocation core radii near elastic stability limits

    NASA Astrophysics Data System (ADS)

    Sawyer, C. A.; Morris, J. W., Jr.; Chrzan, D. C.

    2013-04-01

    Recent studies of transition metal alloys with compositions that place them near their limits of elastic stability [e.g., near the body-centered-cubic (BCC) to hexagonal-close-packed (HCP) transition] suggest interesting behavior for the dislocation cores. Specifically, the dislocation core size is predicted to diverge as the stability limit is approached. Here a simple analysis rooted in elasticity theory and the computation of ideal strength is used to analyze this divergence. This analysis indicates that dislocation core radii should diverge as the elastic limits of stability are approached in the BCC, HCP, and face-centered-cubic (FCC) structures. Moreover, external stresses and dislocation-induced stresses also increase the core radii. Density functional theory based total-energy calculations are combined with anisotropic elasticity theory to compute numerical estimates of dislocation core radii.

  19. Internal stresses, dislocation mobility and ductility

    NASA Astrophysics Data System (ADS)

    Saada, G.

    1991-06-01

    The description of plastic deformation must take into account individual mechanisms and heterogeneity of plastic strain. Influence of dislocation interaction with forest dislocations and of cross slip are connected with the organization of dipole walls. The latter are described and their development is explained as a consequence of edge effects. Applications are discussed. La description de la déformation plastique doit prendre en compte les interactions individuelles des dislocations et l'hétérogénéité à grande échelle de la déformation plastique. Les interactions des dislocations mobiles avec la forêt de dislocations, le glissement dévié, ont pour effet la création de parois dipolaires. Celles-ci sont décrites et leur développement est appliqué à partir des effets de bord.

  20. Short-Term Results of Novel Constrained Total Hip Arthroplasty

    PubMed Central

    Pace, Thomas; Finley, Stephen; Snider, Rebecca; Looper, Jayme; Tanner, Stephanie

    2015-01-01

    Constrained acetabular components have only been recommended as a salvage option for the persistently unstable total hip arthroplasty (THA), due to limited range of motion and less than satisfactory component failure rates. This is a retrospective review of 137 patients with 154 consecutive primary constrained THAs performed between November 2003 and August 2007. We reviewed serial radiographs, postoperative complications, groin/thigh pain, and compared preoperative and postoperative Harris Hip Scores. With a mean follow-up of 6 years, there was 1.9% dislocation rate, 0% component failure rate, and 2.6% infection rate. Seven patients reported continued groin pain, and three had continued thigh pain. One patient showed radiographic evidence of 1 mm polyethylene wear. Radiographic review showed no evidence of osteolysis or stem subsidence. Harris Hip Scores improved from a mean of 68.8 (range 58-87) preoperatively to 98.9 (range 65-100) at final clinical assessment. This constrained acetabular prosthesis had a dislocation rate of less than 2%, with 0% component failure rate at a minimum of 2 years of follow-up suggesting this prosthesis may be a viable alternative for patients at risk for instability or those known to have recurrent instability. PMID:26330992

  1. Prevention of hip fractures.

    PubMed

    Meunier, P J

    1993-11-30

    For a 50-year old Caucasian woman today, the risk of a hip fracture over her remaining life-time is about 17%. Tomorrow the situation will clearly be worse because the continuous increase in life expectancy will cause a three-fold increase in worldwide fracture incidence over the next 60 years. Through diagnostic bone mass measurements at the hip and assessment of biochemical parameters, a great deal has been learned in recent years about reduction of hip fracture risk. Preventive strategies are based on prevention of falls, use of hip protectors, and prevention of bone fragility. The latter includes the optimization of peak bone mass during childhood, postmenopausal estrogen replacement therapy, and also late prevention consisting in reversing senile secondary hyperparathyroidism, which plays an important role in the decrease of skeletal strength. This secondary hyperparathyroidism, which results from both vitamin D insufficiency and low calcium intake, is preventable with vitamin D3 and calcium supplements. They have recently been shown capable of providing effective prevention of hip fractures in elderly women living in nursing homes, with a reduction of about 25% in the number of hip fractures noted in a 3-year controlled study in 3,270 women (intention-to-treat analysis). In conclusion, it is never too early to reduce the risk of osteoporosis and never too late to prevent hip fractures.

  2. A patient-specific model of the biomechanics of hip reduction for neonatal Developmental Dysplasia of the Hip: Investigation of strategies for low to severe grades of Developmental Dysplasia of the Hip.

    PubMed

    Huayamave, Victor; Rose, Christopher; Serra, Sheila; Jones, Brendan; Divo, Eduardo; Moslehy, Faissal; Kassab, Alain J; Price, Charles T

    2015-07-16

    A physics-based computational model of neonatal Developmental Dysplasia of the Hip (DDH) following treatment with the Pavlik Harness (PV) was developed to obtain muscle force contribution in order to elucidate biomechanical factors influencing the reduction of dislocated hips. Clinical observation suggests that reduction occurs in deep sleep involving passive muscle action. Consequently, a set of five (5) adductor muscles were identified as mediators of reduction using the PV. A Fung/Hill-type model was used to characterize muscle response. Four grades (1-4) of dislocation were considered, with one (1) being a low subluxation and four (4) a severe dislocation. A three-dimensional model of the pelvis-femur lower limb of a representative 10 week-old female was generated based on CT-scans with the aid of anthropomorphic scaling of anatomical landmarks. The model was calibrated to achieve equilibrium at 90° flexion and 80° abduction. The hip was computationally dislocated according to the grade under investigation, the femur was restrained to move in an envelope consistent with PV restraints, and the dynamic response under passive muscle action and the effect of gravity was resolved. Model results with an anteversion angle of 50° show successful reduction Grades 1-3, while Grade 4 failed to reduce with the PV. These results are consistent with a previous study based on a simplified anatomically-consistent synthetic model and clinical reports of very low success of the PV for Grade 4. However our model indicated that it is possible to achieve reduction of Grade 4 dislocation by hyperflexion and the resultant external rotation.

  3. Hip Surveillance for Children With Cerebral Palsy: A Survey of the POSNA Membership.

    PubMed

    Shore, Benjamin J; Shrader, Michael W; Narayanan, Unni; Miller, Freeman; Graham, H Kerr; Mulpuri, Kishore

    Currently, hip surveillance programs for children with cerebral palsy exist in Europe, Australasia, and parts of Canada, but a neuromuscular hip surveillance program has yet to be adopted in the United States. The purpose of this study was to report the current orthopaedic practice of hip surveillance in children with cerebral palsy, identify areas of practice variation, and suggest steps moving forward to generate guidelines for national neuromuscular hip surveillance. The entire membership of the Pediatric Orthopaedic Society of North America (POSNA) was surveyed in 2016 for information regarding their practice for hip surveillance in children with cerebral palsy. Detailed information regarding timing, frequency, and practice of hip surveillance was obtained in answers to 26 different questions. A survey response rate of 27% was obtained (350/1300 members) during the study period. The majority of respondents treated pediatric patients exclusively (97%), worked in an academic practice (70%), and was affiliated with a university (76%). In total, 18% (69/350) of respondents followed a regular cerebral palsy hip surveillance program, about half of whom (44%, 30/69) had adopted the Australian guidelines. Respondents agreed that a dislocated hip in a child with cerebral palsy was painful (90% agreement) and should be prevented by hip surveillance (93% agreement). Furthermore, 93% of respondents indicated they would follow a national surveillance program if one was in place. Age (79%), Gross Motor Function Classification System (81%), and migration percentage (MP) (78%) were all identified as critical elements to a hip surveillance program. The majority of respondents felt that a hip "at risk" for hip displacement had a MP between 20% and 30% (57% of respondents), whereas surgery should be utilized once the MP exceeded 40% (50% of respondents). Results from this survey demonstrate 90% of respondents agree that a dislocated hip could be painful and 93% would follow a

  4. [Analysis of the failures of a cemented constrained liner model in patients with a high dislocation risk].

    PubMed

    Gallart, X; Gomez, J C; Fernández-Valencia, J A; Combalía, A; Bori, G; García, S; Rios, J; Riba, J

    2014-01-01

    To evaluate the short-term results of an ultra high molecular weight polyethylene retentive cup in patients at high risk of dislocation, either primary or revision surgery. Retrospective review of 38 cases in order to determine the rate of survival and failure analysis of a constrained cemented cup, with a mean follow-up of 27 months. We studied demographic data, complications, especially re-dislocations of the prosthesis and, also the likely causes of system failure analyzed. In 21.05% (8 cases) were primary surgery and 78.95% were revision surgery (30 cases). The overall survival rate by Kaplan-Meier method was 70.7 months. During follow-up 3 patients died due to causes unrelated to surgery and 2 infections occurred. 12 hips had at least two previous surgeries done. It wasn't any case of aseptic loosening. Four patients presented dislocation, all with a 22 mm head (P=.008). Our statistical analysis didn't found relationship between the abduction cup angle and implant failure (P=.22). The ultra high molecular weight polyethylene retentive cup evaluated in this series has provided satisfactory short-term results in hip arthroplasty patients at high risk of dislocation. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  5. Transient osteoporosis of the hip.

    PubMed

    McWalter, Patricia; Hassan, Ahmed

    2009-01-01

    Transient osteoporosis of the hip is an uncommon cause of hip pain, mostly affecting healthy middle-aged men and also women in the third trimester of pregnancy. We present a case of transient osteoporosis of the hip in a 33-year-old non-pregnant female patient. This case highlights the importance of considering a diagnosis of transient osteoporosis of the hip in patients who present with hip pain.

  6. Evaluation and Referral for Developmental Dysplasia of the Hip in Infants.

    PubMed

    Shaw, Brian A; Segal, Lee S

    2016-12-01

    Developmental dysplasia of the hip (DDH) encompasses a wide spectrum of clinical severity, from mild developmental abnormalities to frank dislocation. Clinical hip instability occurs in 1% to 2% of full-term infants, and up to 15% have hip instability or hip immaturity detectable by imaging studies. Hip dysplasia is the most common cause of hip arthritis in women younger than 40 years and accounts for 5% to 10% of all total hip replacements in the United States. Newborn and periodic screening have been practiced for decades, because DDH is clinically silent during the first year of life, can be treated more effectively if detected early, and can have severe consequences if left untreated. However, screening programs and techniques are not uniform, and there is little evidence-based literature to support current practice, leading to controversy. Recent literature shows that many mild forms of DDH resolve without treatment, and there is a lack of agreement on ultrasonographic diagnostic criteria for DDH as a disease versus developmental variations. The American Academy of Pediatrics has not published any policy statements on DDH since its 2000 clinical practice guideline and accompanying technical report. Developments since then include a controversial US Preventive Services Task Force "inconclusive" determination regarding usefulness of DDH screening, several prospective studies supporting observation over treatment of minor ultrasonographic hip variations, and a recent evidence-based clinical practice guideline from the American Academy of Orthopaedic Surgeons on the detection and management of DDH in infants 0 to 6 months of age. The purpose of this clinical report was to provide literature-based updated direction for the clinician in screening and referral for DDH, with the primary goal of preventing and/or detecting a dislocated hip by 6 to 12 months of age in an otherwise healthy child, understanding that no screening program has eliminated late development or

  7. Hip arthroscopy in the setting of hip dysplasia

    PubMed Central

    Yeung, M.; Kowalczuk, M.; Simunovic, N.

    2016-01-01

    Objective Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia. Methods A systematic search was performed in duplicate for studies investigating the outcome of hip arthroscopy in the setting of hip dysplasia up to July 2015. Study parameters including sample size, definition of dysplasia, outcomes measures, and re-operation rates were obtained. Furthermore, the levels of evidence of studies were collected and quality assessment was performed. Results The systematic review identified 18 studies investigating hip arthroscopy in the setting of hip dysplasia, with 889 included patients. Criteria used by the studies to diagnose hip dysplasia and borderline hip dysplasia included centre edge angle in 72% of studies but the range of angles were quite variable. Although 89% of studies reported improved post-operative outcome scores in the setting of hip dysplasia, revision rates were considerable (14.1%), with 9.6% requiring conversion to total hip arthroplasty. Conclusion The available orthopaedic literature suggests that although improved outcomes are seen in hip arthroscopy in the setting of hip dysplasia, there is a high rate of re-operation and conversion to total hip arthroplasty. Furthermore, the criteria used to define hip dysplasia vary considerably among published studies. Cite this article: M. Yeung, M. Kowalczuk, N. Simunovic, O. R. Ayeni. Hip arthroscopy in the setting of hip dysplasia: A systematic review. Bone Joint Res 2016;5:225–231. DOI: 10.1302/2046-3758.56.2000533. PMID:27313136

  8. Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

    SciTech Connect

    Chen, Qian

    2008-01-01

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  9. Evolution, interaction, and intrinsic properties of dislocations in intermetallics: Anisotropic three-dimensional dislocation dynamics approach

    NASA Astrophysics Data System (ADS)

    Chen, Qian

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  10. Increasing preoperative dislocations and total time of dislocation affect surgical management of anterior shoulder instability

    PubMed Central

    Denard, Patrick J.; Dai, Xuesong; Burkhart, Stephen S.

    2015-01-01

    Purpose: Our purpose was to determine the relationship between number of preoperative shoulder dislocations and total dislocation time and the need to perform bone deficiency procedures at the time of primary anterior instability surgery. Our hypothesis was that need for bone deficiency procedures would increase with the total number and hours of dislocation. Materials and Methods: A retrospective review was performed of primary instability surgeries performed by a single surgeon. Patients with <25% glenoid bone loss were treated with an isolated arthroscopic Bankart repair. Those who also had an engaging Hill-Sachs lesion underwent arthroscopic Bankart repair with remplissage. Patients with >25% glenoid bone loss were treated with Latarjet reconstruction. Number of dislocations and total dislocation time were examined for their relationship with the treatment method. Results: Ten arthroscopic Bankart repairs, 13 arthroscopic Bankart plus remplissage procedures, and 9 Latarjet reconstructions were available for review. Total dislocations (P = 0.012) and total hours of dislocation (P = 0.019) increased from the Bankart, to the remplissage, to the Latarjet groups. Patients with a total dislocation time of 5 h or more were more likely to require a Latarjet reconstruction (P = 0.039). Patients with only 1 preoperative dislocation were treated with an isolated Bankart repair in 64% (7 of 11) of cases, whereas those with 2 or more dislocations required a bone loss procedure in 86% (18 of 21) of cases (P = 0.013). Conclusion: Increasing number of dislocations and total dislocation time are associated with the development of glenoid and humeral head bony lesions that alter surgical management of anterior shoulder instability. The necessity for the addition of a remplissage to an arthroscopic Bankart repair or the use of a Latarjet reconstruction increases with only 1 recurrent dislocation. Level of evidence: Level III, retrospective comparative study. PMID:25709237

  11. Ultrasonic Study of Dislocation Dynamics in Lithium -

    NASA Astrophysics Data System (ADS)

    Han, Myeong-Deok

    1987-09-01

    Experimental studies of dislocation dynamics in LiF single crystals, using ultrasonic techniques combined with dynamic loading, were performed to investigate the time evolution of the plastic deformation process under a short stress pulse at room temperature, and the temperature dependence of the dislocation damping mechanism in the temperature range 25 - 300(DEGREES)K. From the former, the time dependence of the ultrasonic attenuation was understood as resulting from dislocation multiplication followed by the evolution of mobile dislocations to immobile ones under large stress. From the latter, the temperature dependence of the ultrasonic attenuation was interpreted as due to the motion of the dislocation loops overcoming the periodic Peierls potential barrier in a manner analogous to the motion of a thermalized sine-Gordon chain under a small stress. The Peierls stress obtained from the experimental results by application of Seeger's relaxation model with exponential dislocation length distribution was 4.26MPa, which is consistent with the lowest stress for the linear relation between the dislocation velocity and stress observed by Flinn and Tinder.

  12. Chronic bilateral dislocation of temporomandibular joint.

    PubMed

    Shakya, S; Ongole, R; Sumanth, K N; Denny, C E

    2010-01-01

    Dislocation of the condyle of the mandible is a common condition that may occur in an acute or chronic form. It is characterised by inability to close the mouth with or without pain. Dislocation has to be differentiated from subluxation which is a self reducible condition. Dislocation can occur in any direction with anterior dislocation being the commonest one. Various predisposing factors have been associated with dislocation like muscle fatigue and spasm, the defect in the bony surface like shallow articular eminence, and laxity of the capsular ligament. People with defect in collagen synthesis like Ehler Danlos syndrome, Marfan syndrome are said to be genetically predisposed to this condition. Various treatment modalities have been used ranging from conservative techniques to surgical methods. Acute dislocations can be reduced manually or with conservative approach and recurrent and chronic cases can be reduced by surgical intervention. Though the dislocation in our case was 4 months a simple manual reduction proved to be successful. We believe that manual reduction can be attempted as first line of treatment prior to surgical intervention.

  13. Modeling the Dynamics of Dislocation Ensembles

    NASA Astrophysics Data System (ADS)

    Ghoniem, Nasr M.

    A fundamental description of plastic deformation is under development by several research groups as a result of dissatisfaction with the limitations of continuum plasticity theory. The reliability of continuum plasticity descriptions is dependent on the accuracy and range of available experimental data. Under complex loading situations, however, the database is often hard to establish. Moreover, the lack of a characteristic length scale in continuum plasticity makes it difficult to predict the occurrence of critical localized deformation zones. It is widely appreciated that plastic strain is fundamentally heterogenous, displaying high strains concentrated in small material volumes, with virtually undeformed regions in-between. Experimental observations consistently show that plastic deformation is internally heterogeneous at a number of length scales [1-3]. Depending on the deformation mode, heterogeneous dislocation structures appear with definitive wavelengths. It is common to observe persistent slip bands (PSBs), shear bands, dislocation pile ups, dislocation cells and sub grains. However, a satisfactory description of realistic dislocation patterning and strain localization has been rather elusive. Since dislocations are the basic carriers of plasticity, the fundamental physics of plastic deformation must be described in terms of the behavior of dislocation ensembles. Moreover, the deformation of thin films and nanolayered materials is controlled by the motion and interactions of dislocations.

  14. Search for Dislocation Free Helium 4 Crystals.

    PubMed

    Souris, F; Fefferman, A D; Haziot, A; Garroum, N; Beamish, J R; Balibar, S

    The giant plasticity of [Formula: see text]He crystals has been explained as a consequence of the large mobility of their dislocations. Thus, the mechanical properties of dislocation free crystals should be quite different from those of usual ones. In 1996-1998, Ruutu et al. published crystal growth studies showing that, in their helium 4 crystals, the density of screw dislocations along the c-axis was less than 100 per cm[Formula: see text], sometimes zero. We have grown helium 4 crystals using similar growth speeds and temperatures, and extracted their dislocation density from their mechanical properties. We found dislocation densities that are in the range of 10[Formula: see text]-10[Formula: see text] per cm[Formula: see text], that is several orders of magnitude larger than Ruutu et al. Our tentative interpretation of this apparent contradiction is that the two types of measurements are somewhat indirect and concern different types of dislocations. As for the dislocation nucleation mechanism, it remains to be understood.

  15. On Dislocation Glide in Planetary Interiors

    NASA Astrophysics Data System (ADS)

    Cordier, P.; Carrez, P.; Gouriet, K.; Kraych, A.; Ritterbex, S.

    2015-12-01

    The dynamics of hot planets depends strongly on how heat is transported to their surfaces through large scale convection flows. This is ultimately controlled by the rheology of high-pressure phases under extreme conditions. Whenever solid rocks are concerned, plastic flow results from the propagation of crystal defects (point defects, dislocations, grain boundaries). In this presentation we focus on the role of pressure on dislocation glide which is usually the most efficient strain-producing mechanism. Dislocation glide is assessed through multiscale numerical modeling. First, dislocations are modeled at the atomic scale based on first-principles calculations to incorporate the influence of pressure. Then the mobility law of dislocation at finite temperature is modeled by describing thermally-activated mechanisms for dislocation glide based on the kink-pair model. Then the flow stress at the grain scale is deduced either from application of the Orowan equation or by dislocation dynamics modeling. This approach is applied to wadsleyite, ringwoodite, bridgmanite and post-perovskite. Mechanical properties are either calculated at laboratory strain-rates to be compared with experiments when available or at mantle strain-rate to assess their efficiency under natural conditions.

  16. Thermodynamic forces in single crystals with dislocations

    NASA Astrophysics Data System (ADS)

    Van Goethem, Nicolas

    2014-06-01

    A simple model for the evolution of macroscopic dislocation regions in a single crystal is presented. This model relies on maximal dissipation principle within Kröner's geometric description of the dislocated crystal. Mathematical methods and tools from shape optimization theory provide equilibrium relations at the dislocation front, similarly to previous work achieved on damage modelling (J Comput Phys 33(16):5010-5044, 2011). The deformation state variable is the incompatible strain as related to the dislocation density tensor by a relation involving the Ricci curvature of the crystal underlying elastic metric. The time evolution of the model variables follows from a novel interpretation of the Einstein-Hilbert flow in terms of dislocation microstructure energy. This flow is interpreted as the dissipation of non-conservative dislocations, due to the climb mechanism, modelled by an average effect of mesoscopic dislocations moving normal to their glide planes by adding or removing points defects. The model equations are a fourth-order tensor parabolic equation involving the operator "incompatibility," here appearing as a tensorial counterpart of the scalar Laplacian. This work encompasses and generalizes results previously announced (C R Acad Sci Paris Ser I 349:923-927, 2011), with in addition a series of physical interpretations to give a meaning to the newly introduced concepts.

  17. [Epidemiology of hip fracture].

    PubMed

    Hagino, Hiroshi

    2006-12-01

    Age- and gender-specific numbers of patients with hip fracture increase with age and peaked at the age 80-84; however, age- and gender-specific incidences increase exponentially with age. According to the recent nation-wide survey, the most common cause of hip fractures was a simple fall, 68.8% sustained fractures in-doors, and the incidences were higher in the winter than the summer period. More than 90% of patients with hip fracture were treated surgically and about 3/4 of patients with femoral neck fractures were treated with hemi-arthroplasty. Hip fractures for Asian people including Japanese are lower than those for Caucasians living in Northern Europe and North America; however, recent reports from the Asian area indicated an increase in the incidence with time.

  18. Minimally invasive hip replacement

    MedlinePlus

    ... muscles around the hip are cut or detached. Description To perform this surgery: A cut will be ... 30 centimeters) long. The surgeon will use special instruments to work through the small cut. Surgery involves ...

  19. Ultrasound: Infant Hip

    MedlinePlus

    ... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  20. HIP osteoarthritis and work.

    PubMed

    Harris, E Clare; Coggon, David

    2015-06-01

    Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by the elimination or redesign of processes and the use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on the capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment.

  1. Ultrasound: Infant Hip

    MedlinePlus

    ... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  2. Hip joint replacement

    MedlinePlus

    ... A socket, which is usually made of strong metal. A liner, which fits inside the socket. It ... are now trying other materials, like ceramic or metal. The liner allows the hip to move smoothly. ...

  3. HIP OSTEOARTHRITIS AND WORK

    PubMed Central

    Harris, E Clare; Coggon, David

    2016-01-01

    Epidemiological evidence points strongly to a hazard of hip osteoarthritis from heavy manual work. Harmful exposures may be reduced by elimination or redesign of processes and use of mechanical aids. Reducing obesity might help to protect workers whose need to perform heavy lifting cannot be eliminated. Particularly high relative risks have been reported in farmers, and hip osteoarthritis is a prescribed occupational disease in the UK for long-term employees in agriculture. Even where it is not attributable to employment, hip osteoarthritis impacts importantly on capacity to work. Factors that may influence work participation include the severity of disease, the physical demands of the job, age, and the size of the employer. Published research does not provide a strong guide to the timing of return to work following hip arthroplasty for osteoarthritis, and it is unclear whether patients should avoid heavy manual tasks in their future employment. PMID:26612242

  4. Femoral head diameter considerations for primary total hip arthroplasty.

    PubMed

    Girard, J

    2015-02-01

    The configuration of total hip arthroplasty (THA) implants has constantly evolved since they were first introduced. One of the key components of THA design is the diameter of the prosthetic femoral head. It has been well established that the risk of dislocation is lower as the head diameter increases. But head diameter impacts other variables beyond joint stability: wear, cam-type impingement, range of motion, restoration of biomechanics, proprioception and groin pain. The introduction of highly cross-linked polyethylene and hard-on-hard bearings has allowed surgeons to implant large-diameter heads that almost completely eliminate the risk of dislocation. But as a result, cup liners have become thinner. With femoral head diameters up to 36 mm, the improvement in joint range of motion, delay in cam-type impingement and reduction in dislocation risk have been clearly demonstrated. Conversely, large-diameter heads do not provide any additional improvements. If an "ecologically sound" approach to hip replacement is embraced (e.g. keeping the native femoral head diameter), hip resurfacing with a metal-on-metal bearing must be carried out. The reliability of large-diameter femoral heads in the longer term is questionable. Large-diameter ceramic-on-ceramic bearings may be plagued by the same problems as metal-on-metal bearings: groin pain, squeaking, increased stiffness, irregular lubrication, acetabular loosening and notable friction at the Morse taper. These possibilities require us to be extra careful when using femoral heads with a diameter greater than 36 mm. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  5. Distribution of distances between dislocations in different types of dislocation substructures in deformed Cu-Al alloys

    SciTech Connect

    Trishkina, L. Zboykova, N.; Koneva, N. Kozlov, E.; Cherkasova, T.

    2016-01-15

    The aim of the investigation was the determination of the statistic description of dislocation distribution in each dislocation substructures component forming after different deformation degrees in the Cu-Al alloys. The dislocation structures were investigated by the transmission diffraction electron microscopy method. In the work the statistic description of distance distribution between the dislocations, dislocation barriers and dislocation tangles in the deformed Cu-Al alloys with different concentration of Al and test temperature at the grain size of 100 µm was carried out. It was established that the above parameters influence the dislocation distribution in different types of the dislocation substructures (DSS): dislocation chaos, dislocation networks without disorientation, nondisoriented and disoriented cells, in the walls and inside the cells. The distributions of the distances between dislocations in the investigated alloys for each DSS type formed at certain deformation degrees and various test temperatures were plotted.

  6. [Hemi-arthroplasty of the hip joint: concentric or positive eccentric (self-centering) dual head prosthesis? A retrospective comparison].

    PubMed

    Möllers, M; Stedtfeld, H W; Paechtner, S; Wald, A

    1992-05-01

    In femoral neck fractures in the elderly, the least traumatic operative treatment is hemiarthroplasty. In our Trauma Unit, from August 1986 to December 1986 we implanted 22 concentric bipolar cups. During follow-up this cup proved to be associated with an unjustifiably high failure rate: system-caused interprosthetic dislocation in 4 patients (18%), and extraprosthetic dislocation in a further 3 (13%). In one of the latter, interprosthetic disconnection occurred during closed reduction. In all of these, i.e., in 31% out of the 22 patients, conversion to a total hip arthroplasty became necessary. Since March 1987 we have used a positive eccentric, self-centering bipolar head. Up to September 1990 322 such prostheses were implanted. Bearing in mind the reduced general physical condition of the patients, the complication rate is considered to be low (dislocations 3.4%, conversion to total hip arthroplasty 0.9%, deep wound infections 3.1%).

  7. Ultrasonography of the hip.

    PubMed

    Nestorova, Rodina; Vlad, Violeta; Petranova, Tzvetanka; Porta, Francesco; Radunovic, Goran; Micu, Mihaela C; Iagnocco, Annamaria

    2012-09-01

    A complete physical examination of the hip is often difficult due to its size and deep position. During the last two decades, ultrasonography (US) of the hip has been widely accepted as a useful diagnostic tool in patients with hip pain and /or limited range of motion. It is commonly used in both adults and children. This technique allows evaluation of different anatomical structures and their pathological changes, such as joint recess (joint effusion, synovial hypertrophy), changes within the bursae (bursitis), tendons and muscles (tendinopathy, ruptures, calcifications), as well as changes in the bony profile of the joint surfaces, ischial tuberosity, and greater trochanter (erosions, osteophytes, calcific deposits). US is very useful for guided procedures in hip joint and periarticular soft tissues under direct visualization. The needle aspiration of synovial fluid and steroid injections are commonly-applied activities in daily rheumatology practice. The relatively limited acoustic windows available to the US beam are the principal limitations to hip US. Therefore, conducting a detailed examination of some important structures together with the interpretation of Doppler signal (sometimes undetectable) is not easy, requiring good knowledge of the modality. The aim of this review is to analyze the current literature about US of the hip and to describe the most frequently-observed normal and pathological findings.

  8. HIP ARTHROSCOPY IN ATHLETES

    PubMed Central

    Polesello, Giancarlo Cavalli; Keiske Ono, Nelson; Bellan, Davi Gabriel; Honda, Emerson Kiyoshi; Guimarães, Rodrigo Pereira; Junior, Walter Riccioli; Do Val Sella, Guilherme

    2015-01-01

    To confirm the therapeutic importance of hip arthroplasty in athletes whose pain precludes sportive function of the hip joint, being able to minimize it to the extent of helping on the return of sports practice at satisfactory levels. Methods: 49 athlete patients (51 hips) submitted to hip arthroscopy complaining of pain and inability to practice sports were assessed. Follow-up time ranged from 12 to 74 months (mean: 39.0 months). Preoperatively, pain site, severity according to Facial Expression Scale (FES) and the degree of disability using the modified Harris Hip Score (HHS) were assessed. Different diagnoses were provided, which led to the indication of arthroscopy, such as femoralacetabular impact, acetabular lip injury not secondary to femoral-acetabular impact, etc. Postoperatively, the patients were assessed by using the same methods as used at baseline and by the subjective analysis of return to sports activities. Results: Based on pre-and postoperative HHS and FES, the statistical analysis showed significance between values. We found some improvement in all cases and return to sports activities at a satisfactory level in most of the cases. Conclusion: As a result of our study, we confirm that arthroscopy in athletes with local hip injuries is an effective technique, able to promote the return to sports practice in most of the cases, without pain, and with an effective joint function, provided well indicated. PMID:26998449

  9. [Posterior dislocation of the sternoclavicular joint].

    PubMed

    Mäkinen, Tatu; Madanat, Rami; Heinänen, Mikko; Brinck, Tuomas; Pajarinen, Jarkko

    2013-01-01

    Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

  10. Monteggia fracture-dislocations: A Historical Review

    PubMed Central

    Rehim, Shady A.; Maynard, Mallory A.; Sebastin, Sandeep J.; Chung, Kevin C.

    2014-01-01

    The eponym Monteggia fracture-dislocation originally referred to a fracture of the shaft of the ulna accompanied by anterior dislocation of the radial head that was described by Giovanni Battista Monteggia of Italy in 1814. Subsequently, a further classification system based on the direction of the radial head dislocation and associated fractures of the radius and ulna was proposed by Jose Luis Bado of Uruguay in 1958. This article investigates the evolution of treatment, classification, and outcomes of the Monteggia injury and sheds light on the lives and contributions of Monteggia and Bado. PMID:24792923

  11. [Conservative treatment of congenital patellar dislocation].

    PubMed

    Zajonz, D; Schumann, E; Wojan, M; Moche, M; Heyde, C-E

    2017-02-01

    This article presents the rare case of a boy who was born in our hospital with valgus deformity and external rotation of the right lower leg because of congenital patellar dislocation. In the case presented a stable repositioning of the patella could be achieved by redressment with a plaster cast and leg brace. During a 4-year follow-up there were no tendencies towards dislocation during the clinical examination and no dislocation events were documented. In selected cases an attempt at conservative repositioning and retention treatment appears to be worthwhile before surgical treatment is indicated.

  12. Constrained Acetabular Components Used in Revision Total Hip Arthroplasty: A Registry Analysis.

    PubMed

    Lewis, Peter L; Graves, Stephen E; de Steiger, Richard N; Cuthbert, Alana R

    2017-10-01

    Constrained acetabular components have a mechanism to lock in the femoral head. They have been developed to control postoperative dislocation, particularly in revision total hip arthroplasty (THA). Although these components may reduce dislocation, there are durability concerns: with reports of locking mechanism failures and loosening. We wanted to determine the outcome of constrained components in controlling dislocation, and if these components had a higher rate of second revision when compared with standard nonconstrained components. Revision THA procedures from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) with a recorded primary procedure and initial diagnosis of osteoarthritis were used to compare constrained and standard nonconstrained components. Kaplan-Meier estimates of survivorship were calculated, and hazard ratios using Cox proportional hazard models were used to compare groups. There were 9509 THA first-revision procedures and 700 constrained components. Constrained components had a significantly higher revision rate after 3 months when large-head metal-on-metal components were included (hazard ratio = 1.37; P = .005). When large-head metal-on-metal components were excluded, there was no difference in the rate of second revision between the 2 groups. When the analysis was limited to first revision for dislocation, constrained components had a higher second revision rate for further dislocation after 9 months. Constrained acetabular components had similar second-revision rates when compared with standard nonconstrained components, both for all first-revision reasons and when used to treat dislocation. Although possibly used for the more difficult unstable hips, constrained components had a higher rate of second revision for further dislocation. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Design of a hip prosthetic tribometer based on salat gait cycle

    NASA Astrophysics Data System (ADS)

    Towijaya, T.; Ismail, R.; Jamari, J.

    2017-01-01

    Indonesia is the country with the largest muslim population in the world, most of the inhabitants do salat every day. THR (Total Hip Replacement) patients are prohibited from doing salat in normal gait. It leads to the damage of the hip joint prostheses due to impingement and dislocation.This paper reports the design of a pin-on-ring tribometer which is used to measure and analyze the wear volume and the impingement of hip joint prostheses during salat. The modifications of the femoral head and acetabular cup holder are performed to design the reciprocating motion for the movement of the hip prostheses. The interesting finding of the present research is a new mechanism of linked-bar which leads to the feasibility of the measurement of the wear volume and the impingement for THR patients during salat.

  14. Hip pathology in Hutchinson-Gilford progeria syndrome: a report of two children.

    PubMed

    Akhbari, Pouya; Jha, Shilpa; James, Kyle D; Hinves, Barry L; Buchanan, Jamie A F

    2012-11-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder. The estimated incidence is one in 4 million births. Orthopaedic manifestations include abnormality of the hips occurring early in the disease process. Severe coxa valga can be apparent by the age of 2 years. We report two cases of HGPS, one in a 7-year-old girl with avascular necrosis of the left hip and the second in a 13-year-old girl with recurrent traumatic hip dislocations. We demonstrate the pathoanatomical changes in the hip with HGPS using a combination of imaging modalities including radiographic, computed tomographic and MRI scans. These include coxa magna, coxa valga and acetabular dysplasia. We also comment on how these would affect the surgical management of this high-risk group of patients.

  15. Complications Following Direct Anterior Hip Procedures: Costs to Both Patients and Surgeons.

    PubMed

    Lee, Gwo-Chin; Marconi, Dante

    2015-09-01

    A systematic review of the literature on clinical outcomes following direct anterior approach (DAA) hip arthroplasty was performed. An aggregated 11,810 hip procedures were analyzed for intraoperative and early postoperative complications. The most common complication following DAA hip arthroplasty was nerve dysfunction (2.8%) followed by intraoperative fractures (2.3%). Postoperative dislocation, wound complications, and revision THA within the first 12 months were reported in 1.2% of cases. Thus, while DAA hip arthroplasty can be successfully performed, it is not without complications. Without definitive evidence of clinical superiority, surgeons considering switching to DAA should benchmark their personal complication rates against published reports. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. 1-stage primary arthroplasty of mechanically failed internally fixated of hip fractures with deep wound infection

    PubMed Central

    Klatte, Till O; O’Loughlin, Padraigh F; Citak, Mustafa; Rueger, Johannes M; Gehrke, Thorsten; Kendoff, Daniel

    2013-01-01

    Background and purpose Mechanically failed internal fixation following hip fracture is often treated by salvage arthroplasty. If deep wound infection is present, a 2-stage procedure is often used. We have used a 1-stage procedure in infected cases, and we now report the outcome. Patients and methods We reviewed 16 cases of deep wound infection after mechanically failed hip fracture fixation, treated between 1994 and 2010. In all patients, a joint prosthesis was implanted in a 1-stage procedure. Results After an average follow-up period of 12 (2–18) years, no reinfection was detected. In 4 cases, a hip dislocation occurred and 3 of these needed further surgery. Interpretation A 1-stage procedure for arthroplasty of an infected, mechanically failed hip fracture fixation is feasible and carries a low risk of infection. PMID:23799345

  17. Dual mobility cups in total hip arthroplasty

    PubMed Central

    De Martino, Ivan; Triantafyllopoulos, Georgios Konstantinos; Sculco, Peter Keyes; Sculco, Thomas Peter

    2014-01-01

    Total hip arthroplasty (THA) is considered one of the most successful surgical procedures in orthopaedics. With the increase in the number of THAs performed in the world in the next decades, reducing or preventing medical and mechanical complications such as post-operative THA instability will be of paramount importance, particularly in an emerging health care environment based on quality control and patient outcome. Dual mobility acetabular component (also known as unconstrained tripolar implant) was introduced in France at the end of the 1970s as an alternative to standard sockets, to reduce the risk of THA dislocation in patients undergoing primary THA in France. Dual mobility cups have recently gained wider attention in the United States as an alternative option in the prevention and treatment of instability in both primary and revision THA and offer the benefit of increased stability without compromising clinical outcomes and implant longevity. In this article, we review the use of dual mobility cup in total hip arthroplasty in terms of its history, biomechanics, outcomes and complications based on more than 20 years of medical literature. PMID:25035820

  18. "Conjugate channeling" effect in dislocation core diffusion: carbon transport in dislocated BCC iron.

    PubMed

    Ishii, Akio; Li, Ju; Ogata, Shigenobu

    2013-01-01

    Dislocation pipe diffusion seems to be a well-established phenomenon. Here we demonstrate an unexpected effect, that the migration of interstitials such as carbon in iron may be accelerated not in the dislocation line direction ξ, but in a conjugate diffusion direction. This accelerated random walk arises from a simple crystallographic channeling effect. c is a function of the Burgers vector b, but not ξ, thus a dislocation loop possesses the same everywhere. Using molecular dynamics and accelerated dynamics simulations, we further show that such dislocation-core-coupled carbon diffusion in iron has temperature-dependent activation enthalpy like a fragile glass. The 71° mixed dislocation is the only case in which we see straightforward pipe diffusion that does not depend on dislocation mobility.

  19. “Conjugate Channeling” Effect in Dislocation Core Diffusion: Carbon Transport in Dislocated BCC Iron

    PubMed Central

    Ishii, Akio; Li, Ju; Ogata, Shigenobu

    2013-01-01

    Dislocation pipe diffusion seems to be a well-established phenomenon. Here we demonstrate an unexpected effect, that the migration of interstitials such as carbon in iron may be accelerated not in the dislocation line direction , but in a conjugate diffusion direction. This accelerated random walk arises from a simple crystallographic channeling effect. is a function of the Burgers vector b, but not , thus a dislocation loop possesses the same everywhere. Using molecular dynamics and accelerated dynamics simulations, we further show that such dislocation-core-coupled carbon diffusion in iron has temperature-dependent activation enthalpy like a fragile glass. The 71° mixed dislocation is the only case in which we see straightforward pipe diffusion that does not depend on dislocation mobility. PMID:23593255

  20. Effect of pre-existing immobile dislocations on the evolution of geometrically necessary dislocations during fatigue

    NASA Astrophysics Data System (ADS)

    Irastorza-Landa, Ainara; Grilli, Nicolò; Van Swygenhoven, Helena

    2017-07-01

    The role of pre-existing mobile and immobile dislocation densities on the evolution of geometrical necessary dislocation densities (GNDs) during cyclic fatigue in shear is studied using a continuum dislocation-based model incorporated in a crystal plasticity finite element scheme. Clusters with different immobile dislocation densities are implemented in a homogeneous medium containing a certain mobile dislocation density. It is found that whether GND walls are formed around the initial immobile cluster (or not) strongly depends on the absolute values of initial mobile dislocation density and on the ratio between mobile and immobile densities. The results are discussed in terms of the apparent GND densities experimentally obtained using Laue micro-diffraction.

  1. Hip resurfacing versus total hip arthroplasty: a systematic review comparing standardized outcomes.

    PubMed

    Marshall, Deborah A; Pykerman, Karen; Werle, Jason; Lorenzetti, Diane; Wasylak, Tracy; Noseworthy, Tom; Dick, Donald A; O'Connor, Greg; Sundaram, Aish; Heintzbergen, Sanne; Frank, Cy

    2014-07-01

    Metal-on-metal hip resurfacing was developed for younger, active patients as an alternative to THA, but it remains controversial. Study heterogeneity, inconsistent outcome definitions, and unstandardized outcome measures challenge our ability to compare arthroplasty outcomes studies. We asked how early revisions or reoperations (within 5 years of surgery) and overall revisions, adverse events, and postoperative component malalignment compare among studies of metal-on-metal hip resurfacing with THA among patients with hip osteoarthritis. Secondarily, we compared the revision frequency identified in the systematic review with revisions reported in four major joint replacement registries. We conducted a systematic review of English language studies published after 1996. Adverse events of interest included rates of early failure, time to revision, revision, reoperation, dislocation, infection/sepsis, femoral neck fracture, mortality, and postoperative component alignment. Revision rates were compared with those from four national joint replacement registries. Results were reported as adverse event rates per 1000 person-years stratified by device market status (in use and discontinued). Comparisons between event rates of metal-on-metal hip resurfacing and THA are made using a quasilikelihood generalized linear model. We identified 7421 abstracts, screened and reviewed 384 full-text articles, and included 236. The most common study designs were prospective cohort studies (46.6%; n = 110) and retrospective studies (36%; n = 85). Few randomized controlled trials were included (7.2%; n = 17). The average time to revision was 3.0 years for metal-on-metal hip resurfacing (95% CI, 2.95-3.1) versus 7.8 for THA (95% CI, 7.2-8.3). For all devices, revisions and reoperations were more frequent with metal-on-metal hip resurfacing than THA based on point estimates and CIs: 10.7 (95% CI, 10.1-11.3) versus 7.1 (95% CI, 6.7-7.6; p = 0.068), and 7.9 (95% CI, 5.4-11.3) versus 1

  2. Low revision rate after total hip arthroplasty in patients with pediatric hip diseases

    PubMed Central

    2012-01-01

    Background The results of primary total hip arthroplasties (THAs) after pediatric hip diseases such as developmental dysplasia of the hip (DDH), slipped capital femoral epiphysis (SCFE), or Perthes’ disease have been reported to be inferior to the results after primary osteoarthritis of the hip (OA). Materials and methods We compared the survival of primary THAs performed during the period 1995–2009 due to previous DDH, SCFE, Perthes’ disease, or primary OA, using merged individual-based data from the Danish, Norwegian, and Swedish arthroplasty registers, called the Nordic Arthroplasty Register Association (NARA). Cox multiple regression, with adjustment for age, sex, and type of fixation of the prosthesis was used to calculate the survival of the prostheses and the relative revision risks. Results 370,630 primary THAs were reported to these national registers for 1995–2009. Of these, 14,403 THAs (3.9%) were operated due to pediatric hip diseases (3.1% for Denmark, 8.8% for Norway, and 1.9% for Sweden) and 288,435 THAs (77.8%) were operated due to OA. Unadjusted 10-year Kaplan-Meier survival of THAs after pediatric hip diseases (94.7% survival) was inferior to that after OA (96.6% survival). Consequently, an increased risk of revision for hips with a previous pediatric hip disease was seen (risk ratio (RR) 1.4, 95% CI: 1.3–1.5). However, after adjustment for differences in sex and age of the patients, and in fixation of the prostheses, no difference in survival was found (93.6% after pediatric hip diseases and 93.8% after OA) (RR 1.0, CI: 1.0–1.1). Nevertheless, during the first 6 postoperative months more revisions were reported for THAs secondary to pediatric hip diseases (RR 1.2, CI: 1.0–1.5), mainly due to there being more revisions for dislocations (RR 1.8, CI: 1.4–2.3). Comparison between the different diagnosis groups showed that the overall risk of revision after DDH was higher than after OA (RR 1.1, CI: 1.0–1.2), whereas the combined

  3. [Surgical treatment of hip osteoarthritis: hpdete on hip arthroscopy].

    PubMed

    Ilizaliturri Sánchez, Víctor M; Camacho Galindo, Javier

    2007-10-01

    Arthroscopic surgery of the hip is a routine procedure in an increasing number of institutions around the world. Indications for this procedure increase as more experience is developed. Thanks to hip arthroscopy some intraarticular lesions like labral or ligamentum teres tears and cartilage lesions have been recognized. All of these have the potential to develop hip osteoarthritis. Open techniques for the treatment of femoroacetabular impingement have been transformed to arthroscopic techniques. Femoroacetabular impingement has the potential to cause hip osteoarthritis. The role of hip arthroscopy in the treatment of formally established hip osteoarthritis is limited and has better results in young patients with early degenerative changes.

  4. Fundamentals in generalized elasticity and dislocation theory of quasicrystals: Green tensor, dislocation key-formulas and dislocation loops

    NASA Astrophysics Data System (ADS)

    Lazar, Markus; Agiasofitou, Eleni

    2014-12-01

    The present work provides fundamental quantities in generalized elasticity and dislocation theory of quasicrystals. In a clear and straightforward manner, the three-dimensional Green tensor of generalized elasticity theory and the extended displacement vector for an arbitrary extended force are derived. Next, in the framework of dislocation theory of quasicrystals, the solutions of the field equations for the extended displacement vector and the extended elastic distortion tensor are given; that is, the generalized Burgers equation for arbitrary sources and the generalized Mura-Willis formula, respectively. Moreover, important quantities of the theory of dislocations as the Eshelby stress tensor, Peach-Koehler force, stress function tensor and the interaction energy are derived for general dislocations. The application to dislocation loops gives rise to the generalized Burgers equation, where the displacement vector can be written as a sum of a line integral plus a purely geometric part. Finally, using the Green tensor, all other dislocation key-formulas for loops, known from the theory of anisotropic elasticity, like the Peach-Koehler stress formula, Mura-Willis equation, Volterra equation, stress function tensor and the interaction energy are derived for quasicrystals.

  5. A rebound mechanism for misfit dislocation creation in metallic nanolayers

    SciTech Connect

    Henager, Charles H.; Hoagland, Richard G.

    2004-03-01

    A modified version of the Dregia-Hirth rebound mechanism for misfit dislocation creation is observed in atomistic models of CuNi nanolayered structures. Under applied compression glide dislocations in Cu layers undergo a reaction at the CuNi interface to produce another glide dislocation and a misfit dislocation.

  6. Superolateral dislocation of the condyle: report of a rare case.

    PubMed

    Papadopoulos, H; Edwards, R S

    2010-05-01

    Anterior dislocation of the mandibular condyle is commonly seen in patients with chronic dislocation of their temporomandibular joints. Posterior, superior and lateral dislocation is rare. Superolateral dislocation of an intact condyle, let alone intact mandible is uncommon, usually occurring after a traumatic insult to the mandible. The authors report on such a case, and its management.

  7. Anisotropic Dislocation Line Energy and Crack Tip Dislocation Nucleation in (alpha)RDX

    DTIC Science & Technology

    2013-11-01

    November 2013 Anisotropic Dislocation Line Energy and Crack Tip Dislocation Nucleation in αRDX Lynn B. Munday and Jaroslaw Knap Computational ...public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT This work reports on the algorithms used to determine the...anisotropic and isotropic elastic properties of dislocations and their nucleation from a crack tip. The appendix contains a numerical implementation of these

  8. Modular hybrid total hip arthroplasty. Experimental study in dogs

    PubMed Central

    2011-01-01

    Background This prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs. Methods Ten skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation. Results Excellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis. Conclusions The canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb. PMID:21736758

  9. Automated identification and indexing of dislocations in crystal interfaces

    DOE PAGES

    Stukowski, Alexander; Bulatov, Vasily V.; Arsenlis, Athanasios

    2012-10-31

    Here, we present a computational method for identifying partial and interfacial dislocations in atomistic models of crystals with defects. Our automated algorithm is based on a discrete Burgers circuit integral over the elastic displacement field and is not limited to specific lattices or dislocation types. Dislocations in grain boundaries and other interfaces are identified by mapping atomic bonds from the dislocated interface to an ideal template configuration of the coherent interface to reveal incompatible displacements induced by dislocations and to determine their Burgers vectors. Additionally, the algorithm generates a continuous line representation of each dislocation segment in the crystal andmore » also identifies dislocation junctions.« less

  10. Automated identification and indexing of dislocations in crystal interfaces

    SciTech Connect

    Stukowski, Alexander; Bulatov, Vasily V.; Arsenlis, Athanasios

    2012-10-31

    Here, we present a computational method for identifying partial and interfacial dislocations in atomistic models of crystals with defects. Our automated algorithm is based on a discrete Burgers circuit integral over the elastic displacement field and is not limited to specific lattices or dislocation types. Dislocations in grain boundaries and other interfaces are identified by mapping atomic bonds from the dislocated interface to an ideal template configuration of the coherent interface to reveal incompatible displacements induced by dislocations and to determine their Burgers vectors. Additionally, the algorithm generates a continuous line representation of each dislocation segment in the crystal and also identifies dislocation junctions.

  11. Hydrogenated vacancies lock dislocations in aluminium

    SciTech Connect

    Xie, Degang; Li, Suzhi; Li, Meng; Wang, Zhangjie; Gumbsch, Peter; Sun, Jun; Ma, Evan; Li, Ju; Shan, Zhiwei

    2016-11-03

    Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ~103 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strong locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. In conclusion, vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment.

  12. Hydrogenated vacancies lock dislocations in aluminium

    DOE PAGES

    Xie, Degang; Li, Suzhi; Li, Meng; ...

    2016-11-03

    Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ~103 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strongmore » locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. In conclusion, vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment.« less

  13. Hydrogenated vacancies lock dislocations in aluminium

    NASA Astrophysics Data System (ADS)

    Xie, Degang; Li, Suzhi; Li, Meng; Wang, Zhangjie; Gumbsch, Peter; Sun, Jun; Ma, Evan; Li, Ju; Shan, Zhiwei

    2016-11-01

    Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ~103 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strong locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. Vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment.

  14. Quenched pinning and collective dislocation dynamics

    PubMed Central

    Ovaska, Markus; Laurson, Lasse; Alava, Mikko J.

    2015-01-01

    Several experiments show that crystalline solids deform in a bursty and intermittent fashion. Power-law distributed strain bursts in compression experiments of micron-sized samples, and acoustic emission energies from larger-scale specimens, are the key signatures of the underlying critical-like collective dislocation dynamics - a phenomenon that has also been seen in discrete dislocation dynamics (DDD) simulations. Here we show, by performing large-scale two-dimensional DDD simulations, that the character of the dislocation avalanche dynamics changes upon addition of sufficiently strong randomly distributed quenched pinning centres, present e.g. in many alloys as immobile solute atoms. For intermediate pinning strength, our results adhere to the scaling picture of depinning transitions, in contrast to pure systems where dislocation jamming dominates the avalanche dynamics. Still stronger disorder quenches the critical behaviour entirely. PMID:26024505

  15. Decoherence in electron backscattering by kinked dislocations.

    PubMed

    Dudarev; Ahmed; Hirsch; Wilkinson

    1999-03-01

    A model is proposed that explains the origin of the bright contrast of dislocation walls consisting of edge dislocation dipoles in electron channelling contrast images (ECCI) of fatigued crystals, when the incident beam is parallel to the edge dislocations. The model is based on the assumption that the contrast arises from the dislocation segments terminating the dipoles. These are modelled as screw-type kinks which scatter electrons. Scattering by randomly distributed kinks leads to the randomization of phase of transmitted and diffracted beams and suppresses the anomalous transmission of electrons. The predicted behaviour of electron-channeling contrast images agrees well with experimental observations.With apologies for using two beams instead of three!

  16. Hydrogenated vacancies lock dislocations in aluminium

    PubMed Central

    Xie, Degang; Li, Suzhi; Li, Meng; Wang, Zhangjie; Gumbsch, Peter; Sun, Jun; Ma, Evan; Li, Ju; Shan, Zhiwei

    2016-01-01

    Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ∼103 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strong locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. Vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment. PMID:27808099

  17. Dislocation Glasses: Aging during Relaxation and Coarsening

    SciTech Connect

    Bako, B.; Groma, I.; Gyoergyi, G.; Zimanyi, G. T.

    2007-02-16

    The dynamics of dislocations is reported to exhibit a range of glassy properties. We study numerically various versions of 2D edge dislocation systems, in the absence of externally applied stress. Two types of glassy behavior are identified (i) dislocations gliding along randomly placed, but fixed, axes exhibit relaxation to their spatially disordered stable state; (ii) if both climb and annihilation are allowed, irregular cellular structures can form on a growing length scale before all dislocations annihilate. In all cases both the correlation function and the diffusion coefficient are found to exhibit aging. Relaxation in case (i) is a slow power law, furthermore, in the transient process (ii) the dynamical exponent z{approx_equal}6, i.e., the cellular structure coarsens relatively slowly.

  18. Complete dorsal dislocation of the carpal scaphoid with perilunate dorsal dislocation

    PubMed Central

    Kang, Jong Woo; Park, Jong Hoon; Suh, Dong Hun; Park, Jong Woong

    2016-01-01

    Complete dorsal dislocation of the carpal scaphoid combined with dorsal perilunate dislocation is an extremely rare carpal injury. We describe the case of a 23-year-old man who presented with a complete dorsal dislocation of the carpal scaphoid, combined with a perilunate dislocation. Surgical treatment was performed with open reduction and interosseus ligament repair. At 4 years follow up, the patient's wrist pain had completely resolved without limitations of wrist joint motion and without evidence of avascular necrosis of the carpal scaphoid. PMID:27512229

  19. Interactions between glide dislocations and parallel interfacial dislocations in nanoscale strained layers

    SciTech Connect

    Akasheh, F.; Zbib, H. M.; Hirth, J. P.; Hoagland, R. G.; Misra, A.

    2007-08-01

    Plastic deformation in nanoscale multilayered structures is thought to proceed by the successive propagation of single dislocation loops at the interfaces. Based on this view, we simulate the effect of predeposited interfacial dislocation on the stress (channeling stress) needed to propagate a new loop parallel to existing loops. Single interfacial dislocations as well as finite parallel arrays are considered in the computation. When the gliding dislocation and the predeposited interfacial array have collinear Burgers vectors, the channeling stress increases monotonically as the density of dislocations in the array increases. In the case when their Burgers vectors are inclined at 60 deg. , a regime of perfect plasticity is observed which can be traced back to an instability in the flow stress arising from the interaction between the glide dislocation and a single interfacial dislocation dipole. This interaction leads to a tendency for dislocations of alternating Burgers vectors to propagate during deformation leading to nonuniform arrays. Inclusion of these parallel interactions in the analysis improves the strength predictions as compared with the measured strength of a Cu-Ni multilayered system in the regime where isolated glide dislocation motion controls flow, but does not help to explain the observed strength saturation when the individual layer thickness is in the few nanometer range.

  20. Dislocation dynamics simulations of interactions between gliding dislocations and radiation induced prismatic loops in zirconium

    NASA Astrophysics Data System (ADS)

    Drouet, Julie; Dupuy, Laurent; Onimus, Fabien; Mompiou, Frédéric; Perusin, Simon; Ambard, Antoine

    2014-06-01

    The mechanical behavior of Pressurized Water Reactor fuel cladding tubes made of zirconium alloys is strongly affected by neutron irradiation due to the high density of radiation induced dislocation loops. In order to investigate the interaction mechanisms between gliding dislocations and loops in zirconium, a new nodal dislocation dynamics code, adapted to Hexagonal Close Packed metals, has been used. Various configurations have been systematically computed considering different glide planes, basal or prismatic, and different characters, edge or screw, for gliding dislocations with -type Burgers vectors. Simulations show various interaction mechanisms such as (i) absorption of a loop on an edge dislocation leading to the formation of a double super-jog, (ii) creation of a helical turn, on a screw dislocation, that acts as a strong pinning point or (iii) sweeping of a loop by a gliding dislocation. It is shown that the clearing of loops is more favorable when the dislocation glides in the basal plane than in the prismatic plane explaining the easy dislocation channeling in the basal plane observed after neutron irradiation by transmission electron microscopy.

  1. Effect of cup inclination on predicted contact stress-induced volumetric wear in total hip replacement.

    PubMed

    Rijavec, B; Košak, R; Daniel, M; Kralj-Iglič, V; Dolinar, D

    2015-01-01

    In order to increase the lifetime of the total hip endoprosthesis, it is necessary to understand mechanisms leading to its failure. In this work, we address volumetric wear of the artificial cup, in particular the effect of its inclination with respect to the vertical. Volumetric wear was calculated by using mathematical models for resultant hip force, contact stress and penetration of the prosthesis head into the cup. Relevance of the dependence of volumetric wear on inclination of the cup (its abduction angle ϑA) was assessed by the results of 95 hips with implanted endoprosthesis. Geometrical parameters obtained from standard antero-posterior radiographs were taken as input data. Volumetric wear decreases with increasing cup abduction angle ϑA. The correlation within the population of 95 hips was statistically significant (P = 0.006). Large cup abduction angle minimises predicted volumetric wear but may increase the risk for dislocation of the artificial head from the cup in the one-legged stance. Cup abduction angle and direction of the resultant hip force may compensate each other to achieve optimal position of the cup with respect to wear and dislocation in the one-legged stance for a particular patient.

  2. Prolonged unilateral dislocation of the mandible.

    PubMed

    Benny, R A

    1978-08-01

    A 61-year-old white woman dislocated her left condyle. She did not seek care for almost three years. In such a long-standing unilateral dislocation, Gottlieb reported that such extreme adhesions and accumulation of connective tissue develops in the joint cavity that actual reduction is impossible and that violent manipulation may lead to ankylosis. Therefore, in such cases, surgery (condylectomy) is indicated. This was done in our case with good functional results.

  3. Incidence of Posttraumatic Shoulder Dislocation in Poland

    PubMed Central

    Szyluk, Karol J.; Jasiński, Andrzej; Mielnik, Michał; Koczy, Bogdan

    2016-01-01

    Background The incidence of shoulder joint dislocation has been estimated at 11–26 per 100 000 population per year. In our opinion, basic epidemiological data need to be continually updated in studies of large populations. To study the incidence of posttraumatic dislocation of the shoulder joint in the Polish population. Material/Methods We retrospectively investigated the entire Polish population between 1 January 2010 and 1 January 2015. To identify the study group, data collected in the electronic database of the National Health Fund were used. The study group was divided into subgroups to detect possible differences in the incidence of shoulder dislocation with regard to age, sex, and season of the year (month) when the dislocation occurred. Results The cumulative size of the study sample was 192.72 million over the 5 years of the study. We identified 51 409 patients with first posttraumatic shoulder dislocation, at a mean age of 50.83 years (SD 21.12), from 0 to 104 years. The incidence of traumatic shoulder dislocations for the entire study group ranged from 24.75/100 000/year (number of posttraumatic shoulder dislocations per 100 000 persons per year) to 29.09/100 000/year, for a mean of 26.69/100 000/year. Conclusions In this study, the overall incidence of first-time posttraumatic shoulder dislocations in the Polish general population was 26.69 per 100 000 persons per year. These results are higher than estimates presented by other authors. It is necessary to study, regularly update, and monitor this problem in the general population. PMID:27777396

  4. [Custom cementless stem for osteoarthritis following developmental hip dysplasia].

    PubMed

    Flecher, X; Argenson, J N; Parratte, S; Ryembault, E; Aubaniac, J M

    2006-06-01

    Arthroplasty in developmental dysplasia of the hip joint raises technical problems related to the anatomy and age of the young patient. The purpose of this work was to report results obtained with a custom-designed cementless stem. This study included 257 hips reviewed at mean 82 months (range 43-162 months). Mean patient age was 55 years (17-78), mean weight 67 kg (42-118), and mean height 164 cm (147-190). A standard imaging protocol was performed for all patients: AP pelvis in reclining position, AP and lateral views of healthy and pathological hip, AP view of entire lower limb in standing position, computed tomography of lower limb. La position of the greater trochanter and the lengthening necessary was determined from the preoperative films. Stem integration and migration as well as osteolysis were studied postoperatively. Femoral anteversion and the anteroposterior diameter of the paleoacetabulum were measured on the superposed computed tomographic images. Surgery was performed via a Watson-Jones approach to insert a noncemented cup hooked in the obturator foramen and implanted in the paleoacetabulum. The femur endomedullary cavity was prepared with a ream having the form of the definitive stem and the prosthetic neck was custom fit to match the desired lever arm and anteversion. The series included 174 cases of dysplasia and 83 dislocations, 39% stage 1, 30% stage 2, 14% stage 3 and 17% stage 4. Mean lengthening was 39 mm. The mean helitorsion was 28 +/- 16 degrees and the mean anteroposterior diameter of the acetabulum was 51 mm. On average, the alpha correction in the prosthetic neck was -13.4 degrees (-71 degrees to +37 degrees). The Postel-Merle-d'Aubigné score improved from 10.4 points preoperatively to 16.7 points at last follow-up. Postoperative x-rays showed signs of osteointegration in 88% of cases, osteolysis in 5% and one case of stem impaction. Ten hips (3.9%) required revision for replacement (7 for an aseptic problem and 3 for sepsis

  5. Abductor Reconstruction with Gluteus Maximus Transfer in Primary Abductor Deficiency during Total Hip Arthroplasty

    PubMed Central

    Jang, Se Ang; Byun, Young Soo; Gu, Tae Hoe

    2016-01-01

    Abductor deficiency in native hip joint may cause severe limping and pain. It is more serious situation in case of arthroplasty due to instability and recurrent dislocation. Well-known causes of abductor deficiency are repeated surgery, chronic trochanteric bursitis, superior gluteal nerve injury, failure of repair of abductor tendon insertion to the greater trochanter. Author had experienced primary abductor deficiency during total hip replacement and treated successfully with the transfer of gluteus maximus. We'd like to introduce the operation technique with the review of literature. PMID:27777922

  6. Investigation of the Dynamics of a Screw Dislocation in Copper

    NASA Astrophysics Data System (ADS)

    Kolupaeva, S. N.; Petelina, Yu. P.; Polosukhin, K. A.; Petelin, A. E.

    2015-08-01

    A modification of the mathematical model of forming the crystallographic shear band is proposed in which the strength of elastic interaction between all dislocations of the forming dislocation pileups is taken into account in addition to the Peach-Keller force; lattice, impurity, and dislocation friction; linear tension; viscous braking; and intensity of generation of point defects behind kinks. The model is used to investigate the influence of the dislocation density on the time characteristics of the formation of dislocation loops in copper.

  7. Creep Deformation by Dislocation Movement in Waspaloy.

    PubMed

    Whittaker, Mark; Harrison, Will; Deen, Christopher; Rae, Cathie; Williams, Steve

    2017-01-12

    Creep tests of the polycrystalline nickel alloy Waspaloy have been conducted at Swansea University, for varying stress conditions at 700 °C. Investigation through use of Transmission Electron Microscopy at Cambridge University has examined the dislocation networks formed under these conditions, with particular attention paid to comparing tests performed above and below the yield stress. This paper highlights how the dislocation structures vary throughout creep and proposes a dislocation mechanism theory for creep in Waspaloy. Activation energies are calculated through approaches developed in the use of the recently formulated Wilshire Equations, and are found to differ above and below the yield stress. Low activation energies are found to be related to dislocation interaction with γ' precipitates below the yield stress. However, significantly increased dislocation densities at stresses above yield cause an increase in the activation energy values as forest hardening becomes the primary mechanism controlling dislocation movement. It is proposed that the activation energy change is related to the stress increment provided by work hardening, as can be observed from Ti, Ni and steel results.

  8. Creep Deformation by Dislocation Movement in Waspaloy

    PubMed Central

    Whittaker, Mark; Harrison, Will; Deen, Christopher; Rae, Cathie; Williams, Steve

    2017-01-01

    Creep tests of the polycrystalline nickel alloy Waspaloy have been conducted at Swansea University, for varying stress conditions at 700 °C. Investigation through use of Transmission Electron Microscopy at Cambridge University has examined the dislocation networks formed under these conditions, with particular attention paid to comparing tests performed above and below the yield stress. This paper highlights how the dislocation structures vary throughout creep and proposes a dislocation mechanism theory for creep in Waspaloy. Activation energies are calculated through approaches developed in the use of the recently formulated Wilshire Equations, and are found to differ above and below the yield stress. Low activation energies are found to be related to dislocation interaction with γ′ precipitates below the yield stress. However, significantly increased dislocation densities at stresses above yield cause an increase in the activation energy values as forest hardening becomes the primary mechanism controlling dislocation movement. It is proposed that the activation energy change is related to the stress increment provided by work hardening, as can be observed from Ti, Ni and steel results. PMID:28772421

  9. Epidemiology of hip fractures.

    PubMed

    Kannus, P; Parkkari, J; Sievänen, H; Heinonen, A; Vuori, I; Järvinen, M

    1996-01-01

    There were an estimated 1.66 million hip fractures world-wide in 1990. According to the epidemiologic projections, this worldwide annual number will rise to 6.26 million by the year 2050. This rise will be in great part due to the huge increase in the elderly population of the world. However, the age-specific incidence rates of hip fractures have also increased during the recent decades and in many countries this rise has not leveled off. In the districts where this increase has either showed or leveled off, the change seems to especially concern women's cervical fractures. In men, the increase has continued unabated almost everywhere. Reasons for the age-specific increase are not known: increase in the age-adjusted incidence of falls of the elderly individuals with accompanying deterioration in the age-adjusted bone quality (strength, mineral density) may partially explain the phenomenon. The growth of the elderly population will be more marked in Asia, Latin America, the Middle East, and Africa than in Europe and North America, and it is in the former regions that the greatest increments in hip fracture are projected so that these regions will account for over 70% of the 6.26 million hip fractures in the year 2050. The incidence rates of hip fractures vary considerably from population to population and race to race but increase exponentially with age in every group. Highest incidences have been described in the whites of Northern Europe (Scandinavia) and North America. In Finland, for example, the 1991 incidence of hip fractures was 1.1% for women and 0.7% for men over 70 years of age. Among elderly nursing home residents, the figures can be as high as 6.2% and 4.9%. The lifetime risk of a hip fracture is 16%-18% in white women and 5%-6% in white men. At the age of 80 years, every fifth woman and at the age of 90 years almost every second woman has suffered a hip fracture. Since populations are aging worldwide, the mean age of the hip fracture patients are

  10. Hip Resurfacing: An Alternative to Conventional Hip Replacement?

    MedlinePlus

    ... bone is reshaped and capped with a metal prosthesis. The hip socket is fitted with a metal ... but higher levels may be problematic. The socket prosthesis for a traditional hip replacement is usually lined ...

  11. The Hyperflexible Hip

    PubMed Central

    Weber, Alexander E.; Bedi, Asheesh; Tibor, Lisa M.; Zaltz, Ira; Larson, Christopher M.

    2015-01-01

    Context: Dance, gymnastics, figure skating, and competitive cheerleading require a high degree of hip range of motion. Athletes who participate in these sports use their hips in a mechanically complex manner. Evidence Acquisition: A search of the entire PubMed database (through December 2013) and additional searches of the reference lists of pertinent articles. Study Design: Systematic review. Level of Evidence: Level 3. Results: Whether innate or acquired, dancers and gymnasts have some hypermobility that allows their hips to be placed in potentially impinging or unstable positions required for their given activity. Such extremes of motion can result in both intra-articular and extra-articular impingement as well as compensatory osseous and muscular pathology. In addition, dancers and gymnasts are susceptible to impingement-induced instability. Dancers with innate generalized hyperlaxity are at increased risk of injury because of their activities and may require longer recovery times to return to play. Both nonoperative and operative treatments (arthroscopic and open) have an important role in returning flexibility athletes to their preoperative levels of sport and dance. Conclusion: Because of the extreme hip motion required and the compensatory soft tissue laxity in dancers and gymnasts, these athletes may develop instability, impingement, or combinations of both. This frequently occurs in the setting of subtle pathoanatomy or in patients with normal bony anatomy. With appropriate surgical indications and the correct operative technique, the treating surgeon can anticipate high levels of return to play for the gymnast and dancer with hip pain. PMID:26137181

  12. Christiansen's artificial hip joints--what went wrong?

    PubMed

    Sudmann, Einar; Ramstad, Knut Rasmus; Engesæter, Lars Birger

    2013-12-10

    Modern arthroplasty is undoubtedly the greatest contribution that orthopaedic surgery has ever made to medical science. The honour for the good results achieved with total hip replacement surgery goes chiefly to the Briton John Charnley (1911-1982). However, the Norwegian Tor Aas Christiansen (1917-1981) has also earned a place in this history. He wanted to improve the operative treatment of dislocated, medial fractures of the femoral neck, and in the 1960s he constructed a hemiprosthesis. Later, he also made a total prosthesis for the hip joint. Over time, the prostheses proved to be less than successful. Nevertheless, approximately 6,500 Christiansen prostheses were fitted in Norway before a prospective Charnley vs. Christiansen study at the Coastal Hospital in Hagavik finally put an end to his prostheses in 1983. Indirectly, the study led to the establishment of a national register of hip prostheses, now the National Arthroplasty Register, at Haukeland University Hospital. Based on our personal cooperation with Christiansen, as well as original drawings and correspondence from the Polaris factory in Sandnes, we will tell the story of Christiansen's hemi- and total prostheses. These are a key element in the history of hip arthroplasty in Norway.

  13. Creep of quartz by dislocation and grain boundary processes

    NASA Astrophysics Data System (ADS)

    Fukuda, J. I.; Holyoke, C. W., III; Kronenberg, A. K.

    2015-12-01

    Wet polycrystalline quartz aggregates deformed at temperatures T of 600°-900°C and strain rates of 10-4-10-6 s-1 at a confining pressure Pc of 1.5 GPa exhibit plasticity at low T, governed by dislocation glide and limited recovery, and grain size-sensitive creep at high T, governed by diffusion and sliding at grain boundaries. Quartz aggregates were HIP-synthesized, subjecting natural milky quartz powder to T=900°C and Pc=1.5 GPa, and grain sizes (2 to 25 mm) were varied by annealing at these conditions for up to 10 days. Infrared absorption spectra exhibit a broad OH band at 3400 cm-1 due to molecular water inclusions with a calculated OH content (~4000 ppm, H/106Si) that is unchanged by deformation. Rate-stepping experiments reveal different stress-strain rate functions at different temperatures and grain sizes, which correspond to differing stress-temperature sensitivities. At 600-700°C and grain sizes of 5-10 mm, flow law parameters compare favorably with those for basal plasticity and dislocation creep of wet quartzites (effective stress exponents n of 3 to 6 and activation enthalpy H* ~150 kJ/mol). Deformed samples show undulatory extinction, limited recrystallization, and c-axis maxima parallel to the shortening direction. Similarly fine-grained samples deformed at 800°-900°C exhibit flow parameters n=1.3-2.0 and H*=135-200 kJ/mol corresponding to grain size-sensitive Newtonian creep. Deformed samples show some undulatory extinction and grain sizes change by recrystallization; however, grain boundary deformation processes are indicated by the low value of n. Our experimental results for grain size-sensitive creep can be compared with models of grain boundary diffusion and grain boundary sliding using measured rates of silicon grain boundary diffusion. While many quartz mylonites show microstructural and textural evidence for dislocation creep, results for grain size-sensitive creep may apply to very fine-grained (<10 mm) quartz mylonites.

  14. Selective lengthening of the psoas and rectus femoris and preservation of the iliacus for flexion deformity of the hip in cerebral palsy patients.

    PubMed

    Matsuo, T; Hara, H; Tada, S

    1987-01-01

    Between 1978 and 1983, 52 Japanese patients with cerebral palsy underwent operative correction of flexion deformity of the hip. The results of lengthening of the psoas, rectus femoris, and proximal hamstrings were satisfactory. The iliacus was left intact. Improvement in gait and activities of daily living was attained. Concentric reduction was obtained in 27 of 33 dislocated or subluxated hips. Sitting and perineal care were facilitated, and pain was alleviated. We conclude that preservation of the iliacus is important.

  15. Biodynamic total hip prosthesis.

    PubMed

    Pipino, F; Calderale, P M

    1987-09-01

    The biodynamic total hip prosthesis which was devised in 1977-78 and implanted in 1979 was derived from a series of experimental studies and a lengthy clinical experience, both dating back to 1968. This prosthesis introduced two new and original concepts into the field of prosthetic hip surgery: 1) the biequatorial design of the cup; 2) the preservation of the femoral neck. This prosthetic system is based on maximum preservation of the bone stock as well as hip function. The biequatorial cup allows for positioning corresponding to that of the normal acetabulum. The femoral component incorporates features (collar, sagittal and frontal angulation, external surface, etc.) which facilitate proximal cortical fixation and cancellous metaphyseal biological anchoring, thus ensuring total adhesion. The average 3.5 years follow-up (maximum 7 years, minimum one year) in 280 cases confirms the effectiveness of this prosthesis and the validity of the basic principles on which it is founded.

  16. Hip impingement: beyond femoroacetabular

    PubMed Central

    Bardakos, Nikolaos V.

    2015-01-01

    In the last 20 years, femoroacetabular impingement has been at the forefront of clinical practice as a cause of hip pain in young adults. As arthroscopic techniques for the hip continue to evolve, the possible presence of a new group of conditions creating mechanical conflict in and around the hip joint (ischiofemoral, subspine and iliopsoas impingement) has recently been elucidated whilst interest in already known ‘impingement’ syndromes (pelvic-trochanteric and pectineofoveal impingement) is now revived. This article attempts to increase awareness of these relatively uncommon clinical entities by describing their pathomorphology, contact mechanics, treatment and published results available to present. It is hoped that such knowledge will diversify therapeutic options for the clinician, thereby improving outcomes in a small but not negligible portion of patients with previously unexplained persistent symptoms. PMID:27011843

  17. Hip fractures in children.

    PubMed

    Boardman, Matthew J; Herman, Martin J; Buck, Brian; Pizzutillo, Peter D

    2009-03-01

    Hip fractures account for <1% of all pediatric fractures. Most are caused by high-energy mechanisms, but pathologic hip fractures also occur, usually from low-energy trauma. Complications occur at a high rate because the vascular and osseous anatomy of the child's proximal femur is vulnerable to injury. Surgical options vary based on the child's age, Delbet classification type, and degree of displacement. Anatomic reduction and surgical stabilization are indicated for most displaced hip fractures. Other options include smooth-wire or screw fixation, often supplemented by spica cast immobilization in younger children, or compression screw and side plate fixation. Achievement of fracture stability is more important than preservation of the proximal femoral physis. Capsular decompression after reduction and fixation may diminish the risk of osteonecrosis. Osteonecrosis, coxa vara, premature physeal closure of the proximal femur, and nonunion are complications that account for poor outcomes.

  18. Hip joint replacement - series (image)

    MedlinePlus

    ... hip socket. The socket is usually made of metal. A liner that fits inside the socket. It ... usually plastic, but some surgeons use ceramic and metal. The liner allows the hip to move smoothly. ...

  19. X-Ray Exam: Hip

    MedlinePlus

    ... amount of radiation to make images of the hip joints (where the legs attach to the pelvis). During ... beam of radiation through the pelvic bones and hip joints, and an image is recorded on a computer ...

  20. Efficacy of Debridement for Early Periprosthetic Joint Infection after Hip Arthroplasty

    PubMed Central

    Kim, Jong Hoon; Chun, Sung Kwang; Yoon, Yong Cheol; Lakhotia, Devendra

    2014-01-01

    Purpose In early prosthetic joint infection after hip arthroplasty, debridement with prosthesis retention may be performed for implant salvage, but the reported success rates are highly variable. Hence we reviewed the outcome of radical debridement and retention of prosthesis using established diagnostic criteria and surgical procedures in relation to significant variables including clinical characteristics, pathogenicity, and antibiotic treatment. Materials and Methods We retrospectively reviewed 20 patients (11 men and 9 women) with early prosthetic joint infection after unilateral hip arthroplasty, treated by radical debridement with retention of prosthesis from January 2000 to May 2011. Average follow-up period was 55 months (12-178 months). The outcome was evaluated and analyzed based on recurrence of infection and clinical (Harris hip score) and radiological criteria. Results Pathogens were isolated from 11 hips (methicillin-resistant Staphylococcus aureus [MRSA] in three, methicillin-resistant Staphylococcus epidermidis [MRSE] in two, methicillin-sensitive Staphylococcus aureus [MSSA] in one, Acinetobacter baumannii in two, Enterococcus faecalis in two patients, and Enterococcus, Citrobacter species in one). The mean duration of antibiotic administration was 43.5 days. Recurrence of infection was not observed in any case. Average Harris hip score was 91 points at the last follow-up. Revision surgery was not required for any reason including implant failure. Dislocation occurred in two hips after debridement and was treated conservatively. Conclusion Radical debridement with prosthesis retention is an effective procedure for early prosthetic joint infection after hip arthroplasty in carefully selected patients and with early diagnosis. PMID:27536586

  1. Extra-articular hip endoscopy

    PubMed Central

    Verhelst, L.; Guevara, V.; De Schepper, J.; Van Melkebeek, J.; Pattyn, C.; Audenaert, E. A.

    2012-01-01

    The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy. PMID:23610664

  2. Quantum dynamics of a single dislocation

    NASA Astrophysics Data System (ADS)

    de Gennes, Pierre-Gilles

    We discuss the zero temperature motions of an edge dislocation in a quantum solid (e.g., He4). If the dislocation has one kink (equal in length to its Burgers vector b) the kink has a creation energy U and can move along the line with a certain transfer integral t. When t and U are of comparable magnitude, two opposite kinks can form an extended bound state, with a size l. The overall shape of the dislocation in the ground state is then associated with a random walk of persistence length l (along the line) and hop sizes b. We also discuss the motions of kinks under an applied shear stress σ: the glide velocity is proportional to exp(-σ*/σ), where σ* is a characteristic stress, controlled by tunneling processes. Mouvements quantiques d'une dislocation. On analyse le mouvement à température nulle d'une dislocation coin dans un solide quantique (He4). La dislocation peut avoir un cran (d'énergie U) dans son plan de glissement. Le cran peut avancer ou reculer le long de la dislocation par effet tunnel, avec une certaine intégrale de transfert t. Deux crans de signe opposé peuvent former un état lié. En présence d'une contrainte extérieure σ, la ligne doit avancer avec une vitesse ~exp(-σ*/σ) où σ* est une contrainte seuil, contrôlée par l'effet tunnel.

  3. Do hip replacements improve outcomes for hip fracture patients?

    PubMed

    Burns, R B; Moskowitz, M A; Ash, A; Kane, R L; Finch, M; McCarthy, E P

    1999-03-01

    Hip fracture is a common problem among older Americans. Two types of procedures are available for repairing hip fractures: hip replacement and open or closed reduction with or without internal fixation. The assumption has been that hip replacement produces better functional outcomes. Although that is the common wisdom, outcome studies evaluating hip replacement for treatment of hip fracture are few and have not clearly documented its superiority. To compare outcomes of hip fracture patients who receive hip replacement versus another stabilizing procedure (open or closed reduction with or without internal fixation). Prospective cohort study. We studied 332 patients (age, > 65) who were hospitalized for a femoral neck fracture and discharged alive. We examined 2 treatment groups, hip replacement versus another procedure, on 6 outcomes [Activities of Daily Living (ADLs), walking, living situation (institutionalized or not), perceived health (excellent/good vs. fair/poor), rehospitalization, and mortality] at 3 postdischarge times (6 weeks, 6 months and 1 year). Mean age was 80, 80% were female, 96% White, 28% married, and 71% had a hip replacement. The treatment groups were similar at baseline (3 months before admission as reported at discharge) on ADLs, walking, living situation, and perceived health (all P > 0.24). After adjusting for demographics, clinical characteristics, fracture characteristics, and prior ADLs, walking ability, living situation, and perceived health, patients with a hip replacement did not do better at 6 weeks, 6 months, or 1 year post-discharge on any of the 6 outcome measures (all 18 P > 0.10). A global test of all 6 outcomes finds hip replacement patients doing less well at one year (P = 0.02). Despite the commonly held belief that hip replacement is a superior treatment for hip fracture, we found no suggestion of better outcomes for hip replacement on any of 6 key outcomes.

  4. Dual-mobility cups for revision due to instability are associated with a low rate of re-revisions due to dislocation

    PubMed Central

    2012-01-01

    Background and purpose Revision total hip arthroplasty (THA) due to recurrent dislocations is associated with a high risk of persistent instability. We hypothesized that the use of dual-mobility cups would reduce the risk of re-revision due to dislocation after revision THA. Patients and methods 228 THA cup revisions (in 228 patients) performed due to recurrent dislocations and employing a specific dual-mobility cup (Avantage) were identified in the Swedish Hip Arthroplasty Register. Kaplan-Meier survival analysis was performed with re-revision due to dislocation as the primary endpoint and re-revision for any reason as the secondary endpoint. Cox regression models were fitted in order to calculate the influence of various covariates on the risk of re-revision. Results 58 patients (25%) had been revised at least once prior to the index cup revision. The surgical approach at the index cup revision was lateral in 99 cases (44%) and posterior in 124 cases (56%). Median follow-up was 2 (0–6) years after the index cup revision, and by then 18 patients (8%) had been re-revised for any reason. Of these, 4 patients (2%) had been re-revised due to dislocation. Survival after 2 years with the endpoint revision of any component due to dislocation was 99% (95% CI: 97–100), and it was 93% (CI: 90–97) with the endpoint revision of any component for any reason. Risk factors for subsequent re-revision for any reason were age between 50–59 years at the time of the index cup revision (risk ratio (RR) = 5 when compared with age > 75, CI: 1–23) and previous revision surgery to the relevant joint (RR = 1.7 per previous revision, CI: 1–3). Interpretation The risk of re-revision due to dislocation after insertion of dual-mobility cups during revision THA performed for recurrent dislocations appears to be low in the short term. Since most dislocations occur early after revision THA, we believe that this device adequately addresses the problem of recurrent instability. Younger

  5. Targeted Screening of Hip Dysplasia in Newborns: Experience at a District General Hospital in Scotland

    PubMed Central

    Tyagi, Rahul; Zgoda, Marcin R.; Short, Rachel

    2016-01-01

    National Health Service Quality Improvement Scotland (NHS QIS) published a health technology scoping report in 2006 acknowledging that there are serious concerns within Scotland in relation to Developmental Dysplasia of Hip (DDH) as there is no formal screening program in place and there are significant variations between NHS boards leading to confusion for staff and parents. NHS QIS identified need for audit work to improve hip screening in Scotland. The aim of this study is review of current practice of selective screening for DDH. All newborns who had their first hip scan during one year period (2014) were included in this retrospective study and followed up until June 2015 to include any surgical intervention for dysplastic hip. Out of 428 babies (856 hip scans), abnormality was seen in 119 babies/147 hips (134 Graf 2a/2b, 10 hips were 2c and 3 hips were Graf grade 3). Average age when first scan was performed was 5 weeks (range 3 weeks to 22 weeks). Analysis of risk factors in 119 babies with abnormal scan was consistent with literature (83 breech, 12 family history, 12 HBW, 10 instability and 2 twins of breech). Twelve babies (16 hips) required treatment and were successfully treated in Pavlik harness. There was one case of missed/late dislocation, which lived in outside catchment area for 3 years since birth. During this study period there was no case of avascular necrosis or femoral nerve palsy as a result of treatment. In our experience, selective hip screening by ultrasound scan is useful in avoiding overtreatment and minimizing late presentations. PMID:27761220

  6. Hip injuries in young athletes.

    PubMed

    Smith, David V; Bernhardt, David T

    2010-01-01

    The hip is an area of the body commonly injured in athletes and one that requires special consideration in the pediatric and adolescent athlete. This article reviews diagnoses specific to the young athlete and discusses more recent advances in imaging of the hip and arthroscopic treatment of the hip in the young athlete.

  7. X-Ray Exam: Hip

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip A A A What's in this ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that uses ...

  8. Developmental Dysplasia of the Hip

    MedlinePlus

    ... to 2-Year-Old Developmental Dysplasia of the Hip KidsHealth > For Parents > Developmental Dysplasia of the Hip A A A What's in this article? What ... Symptoms Diagnosis Treatment Outlook Developmental dysplasia of the hip (DDH) is a problem with the way a ...

  9. Continuum Theory of Dislocations: Cell Structure Formation

    NASA Astrophysics Data System (ADS)

    Limkumnerd, Surachate; Sethna, James P.

    2005-03-01

    Line-like topological defects inside metals are called dislocations. These dislocations in late stages of hardening form patterns called cell structures. We are developing a mesoscale theory for the formation of cell structures that systematically derives the order parameter fields and evolution laws from the conserved topological Burgers vector density or the Nye dislocation tensor. (In classical plasticity theories, describing scales large compared to these cells, one normally bypasses the complicated motions of the dislocations by supplying yield surface and plastic hardening function in order to determine the evolution of state variables.) Using Landau approach and a closure approximation, an evolution equation for the dislocation density tensor is obtained by employing simple symmetry arguments and the constraint that the elastic energy must decrease with time at fixed stress. The evolution laws lead to singularity formation at finite times, which we expect will be related to the formation of cell walls. Implementation of finite difference simulations using the upwind scheme and the results in one and higher dimensions will be discussed.

  10. Recurrent elbow dislocation--an uncommon presentation.

    PubMed

    Sunderamoorthy, D; Smith, A; Woods, D A

    2005-09-01

    A 58 year old female attended our A&E department following a fall in the garden with swelling and bruising of the right arm and the elbow. Anteroposterior and lateral radiographs were interpreted as showing a normal elbow joint. A diagnosis of soft tissue injury to the elbow was made and the patient was discharged with advice. She returned 2 days later, did not have an x ray, and again given advice. Three weeks later she was referred back to A&E by the general practitioner with persistent swelling of the elbow. Further radiographs showed a posterolateral dislocation of the elbow. The elbow was reduced under sedation but was subsequently dislocated at follow up, and was treated by external fixator and transolecranon pin. The fixator was removed at 4 weeks and the elbow was then stable. This case highlights that recurrent elbow dislocations due to significant ligament injuries can present in joint and subsequently dislocate. A high index of suspicion is necessary and appropriate referral to the specialist must be made to avoid the morbidity associated with recurrent dislocation. It also emphasises the need to always assess the patient on his or her own merits despite previously normal investigations.

  11. Use of cervical collar in temporomandibular dislocation.

    PubMed

    Jaisani, Mehul R; Pradhan, Leeza; Sagtani, Alok

    2015-06-01

    Dislocation of the temporomandibular joint represents 3 % of all reported dislocated joints. In the last 3 decades many cases of TMJ dislocation have been reported with a wide variety of treatment options ranging from non-surgical conservative approaches to open joint procedures. The question remains whether one method is superior to the others. Conservative treatments are still the option in this part of the continent due to financial constraints and as well as due to availability of skilled manpower. A variety of conservative techniques have been described for reducing dislocations, all of which require 10-14 days of immobilization of the jaw post reduction so as to prevent further episodes of dislocation. Immobilization of the jaw can be done in the form of barrel bandage, barton bandage, head chin cap or maxillomandibular fixation using arch bars. We suggest the use of a cervical collar as a form of post reduction immobilization technique to overcome the inherent disadvantages of conventional forms of immobilization techniques.

  12. COMPLICATIONS IN HIP ARTHROSCOPY

    PubMed Central

    Contreras, Marcos Emílio Kuschnaroff; Hoffmann, Rafael Barreiros; de Araújo, Lúcio Cappelli Toledo; Dani, William Sotau; José Berral, Francisco

    2015-01-01

    Objectives: To determine the prevalence of complications in a series of consecutive cases of hip arthroscopy; to assess the progression of the sample through a learning curve; and to recognize the causes of complications in arthroscopic hip operations. Method: 150 consecutive cases that underwent hip arthroscopy between May 2004 and December 2008 were evaluated. The complications encountered were classified in three ways: organic system affected, severity and groups of 50 consecutive cases. The data were analyzed by means of descriptive statistics and Fisher's exact test. Results: We observed 15 complications in this study (10%): ten were neurological, two were osteoarticular, one was vascular-ischemic and two were cutaneous. In the classification of severity, three were classified as major, 12 as intermediate and none as minor. The incidence of complications over the course of the learning curve did not present any statistically significant difference (p = 0.16). Conclusions: Hip arthroscopy is a surgical procedure that involves low morbidity, but which presents complications in some cases. These complications are frequently neurological and transitory, and mainly occur because of joint traction. The complication rate did not decrease with progression of our sample. PMID:27022521

  13. Treatment of hip instability.

    PubMed

    Robbins, G M; Masri, B A; Garbuz, D S; Greidanus, N; Duncan, C P

    2001-10-01

    Instability after total hip arthroplasty is a major source of patient morbidity, second only to aseptic loosening. Certain patient groups have been identified as having a greater risk of instability, including patients undergoing revision arthroplasty as early or late treatment for proximal femoral fractures.

  14. HIP quench technology

    SciTech Connect

    Bergman, C.; Westerlund, J.; Zimmerman, F.X.

    1996-12-31

    Hot Isostatic Pressing (HIP) is a viable production process today for densifying metals, ceramics, and composites to achieve fully dense parts. One major drawback for conventional HIPing is the long ten to twelve hour cycle time resulting in low productivity and high processing cost. Drastic furnace improvements have been made in the late 1980`s with the advent of Uniform Rapid Cooling (URC) called HIP Quenching. This innovation allows floor/floor cycles as short as four to five hours with one hour soak depending on the material to be HIPed. A flow device such as a fan is utilized at the base of the furnace for forced gas convection in promoting main features to: (1) accelerate time for heating, soaking and cooling; (2) add combined solution heat treating; and (3) reduce thermal distortion of parts with varying cross-sections. All three points promise to positively effect better economy with improved property and quality to promote the HIP process further. This paper describes the URC technology and illustrates a couple of HIP Quench studies made for a turbine disc and efficient High Speed Steel powder consolidation.

  15. INL HIP Plate Fabrication

    SciTech Connect

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  16. Chiral anomaly in Dirac semimetals due to dislocations

    NASA Astrophysics Data System (ADS)

    Chernodub, M. N.; Zubkov, M. A.

    2017-03-01

    The dislocation in Dirac semimetal carries an emergent magnetic flux parallel to the dislocation axis. We show that due to the emergent magnetic field, the dislocation accommodates a single fermion massless mode of the corresponding low-energy one-particle Hamiltonian. The mode is propagating along the dislocation with its spin directed parallel to the dislocation axis. In agreement with the chiral anomaly observed in Dirac semimetals, an external electric field results in the spectral flow of the one-particle Hamiltonian, in pumping of the fermionic quasiparticles out from vacuum, and in creating a nonzero axial (chiral) charge in the vicinity of the dislocation.

  17. High dislocation density of tin induced by electric current

    SciTech Connect

    Liao, Yi-Han; Liang, Chien-Lung; Lin, Kwang-Lung; Wu, Albert T.

    2015-12-15

    A dislocation density of as high as 10{sup 17} /m{sup 2} in a tin strip, as revealed by high resolution transmission electron microscope, was induced by current stressing at 6.5 x 10{sup 3} A/ cm{sup 2}. The dislocations exist in terms of dislocation line, dislocation loop, and dislocation aggregates. Electron Backscattered Diffraction images reflect that the high dislocation density induced the formation of low deflection angle subgrains, high deflection angle Widmanstätten grains, and recrystallization. The recrystallization gave rise to grain refining.

  18. INNOPLANT Total Hip Replacement System.

    PubMed

    Harper, Tisha A M

    2017-07-01

    Total hip replacement is a salvage procedure that is done to alleviate discomfort secondary to osteoarthritis in the hip, which is most often a result of hip dysplasia. Commercially available total hip replacement implants for small animal patients are classified as cemented or cementless. The INNOPLANT Total Hip Replacement system includes modular, screw-in cementless components that were developed to improve implant stability by maintaining as much normal anatomic structure, and by extension biomechanics of the coxofemoral joint, as possible. As a newer system, there are few data and no long-term studies available in the veterinary literature. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Early Attempts at Hip Arthroplasty

    PubMed Central

    Gomez, Pablo F; Morcuende, Jose A

    2005-01-01

    Over the last three centuries, treatment of hip arthritides has evolved from rudimentary surgery to modern total hip arthroplasty (THA), which is considered one of the most successful surgical interventions ever developed. We here review the history of the early hip arthroplasty procedures for hip arthritis that preceded Charley total hip arthroplasty. An evaluation of such past enterprises is relevant, and reminds us of the ephemeral nature of human industriousness, and how medical research and procedures are not isolated developments, but correlate to the social, economical, and cultural framework of their time. PMID:16089067

  20. Hip Arthroscopy: A Brief History.

    PubMed

    Kandil, Abdurrahman; Safran, Marc R

    2016-07-01

    Hip arthroscopy is a fast-growing and evolving field. Like knee and shoulder arthroscopy, hip arthroscopy began as a diagnostic procedure and then progressed to biopsy and resection of abnormalities. Subsequently, it has evolved to repair of various tissues and treatment of underlying causes. As the understanding of the hip joint and its associated pathophysiology grows, indications will continue to expand for this diagnostic and therapeutic modality. This article outlines the historic developments of hip arthroscopy, including advancements in instrumentation and techniques from the days of the first hip arthroscopies to the present day.

  1. Crack Tip Dislocation Nucleation in FCC Solids

    NASA Astrophysics Data System (ADS)

    Knap, J.; Sieradzki, K.

    1999-02-01

    We present results of molecular dynamic simulations aimed at examining crack tip dislocation emission in fcc solids. The results are analyzed in terms of recent continuum formulations of this problem. In mode II, Au, Pd, and Pt displayed a new unanticipated mechanism of crack tip dislocation emission involving the creation of a pair of Shockley partials on a slip plane one plane below the crack plane. In mode I, for all the materials examined, Rice's continuum formulation [J. Mech. Phys. Solids 40, 239 (1992)] underestimated the stress intensity for dislocation emission by almost a factor of 2. Surface stress corrections to the emission criterion brought the agreement between continuum predictions and simulations to within 20%.

  2. Chronic Elbow Dislocation: Evaluation and Management.

    PubMed

    Donohue, Kenneth W; Mehlhoff, Thomas L

    2016-07-01

    Chronic elbow dislocation is defined as a dislocation that has remained unreduced for >2 weeks. The soft-tissue and skeletal changes that develop during this time usually prevent successful closed reduction. These changes include the development of extensive intra-articular fibrotic tissue, as well as contracture of the triceps, collateral ligaments, and elbow capsule. Ulnar nerve involvement and associated fractures may also be present. Because treatment of chronic elbow dislocation is challenging, a stepwise approach is used in the evaluation and management of this condition. No large series of data are available to guide treatment. Most patients are treated on the basis of the surgeon's anecdotal experience. Treatment typically involves open reduction, often with the use of hinged external fixators. The role of triceps lengthening or primary collateral ligament reconstruction remains a topic of debate.

  3. Composite Dislocations in Smectic Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Aharoni, Hillel; Machon, Thomas; Kamien, Randall D.

    2017-06-01

    Smectic liquid crystals are characterized by layers that have a preferred uniform spacing and vanishing curvature in their ground state. Dislocations in smectics play an important role in phase nucleation, layer reorientation, and dynamics. Typically modeled as possessing one line singularity, the layer structure of a dislocation leads to a diverging compression strain as one approaches the defect center, suggesting a large, elastically determined melted core. However, it has been observed that for large charge dislocations, the defect breaks up into two disclinations [C. E. Williams, Philos. Mag. 32, 313 (1975), 10.1080/14786437508219956]. Here we investigate the topology of the composite core. Because the smectic cannot twist, transformations between different disclination geometries are highly constrained. We demonstrate the geometric route between them and show that despite enjoying precisely the topological rules of the three-dimensional nematic, the additional structure of line disclinations in three-dimensional smectics localizes transitions to higher-order point singularities.

  4. Evaluation of dislocation energy in thin films

    NASA Astrophysics Data System (ADS)

    Coppeta, R. A.; Holec, D.; Ceric, H.; Grasser, T.

    2015-01-01

    A procedure is proposed to calculate the energy of a misfit dislocation at the interface of a film with a finite thickness and a substrate with semi-infinite thickness when modelled anisotropically and with different elastic properties. The results are compared with the treatments derived by Steeds, Willis, Jain and Bullough, and Freund. The new formula is used to calculate the equilibrium critical thickness for Al?Ga?N/GaN, In?Ga?N/GaN and Si?Ge?/Si heterostructures. A comparison with experimental data from the literature shows good agreement. In contrast to other models, application of the new formula for dislocation energy yields smaller critical thickness for the onset of the misfit dislocations.

  5. Successful Conservative Management of a Dislocated IUD

    PubMed Central

    Inal, Hasan Ali; Ozturk Inal, Zeynep; Alkan, Ender

    2015-01-01

    Background. Intrauterine contraceptive devices (IUDs) are widely utilized all over the world owing to their low cost and high efficacy. Uterine perforation is a rare complication that may occur at IUD insertion resulting in extrauterine location of the IUD. Traditionally, surgical removal of dislocated IUDs has been recommended. Case. A 68-year-old patient who had an IUD (Lippes loop) inserted 32 years ago and whose routine examination incidentally revealed a dislocated IUD in the abdominal cavity. The patient remained asymptomatic during three years of follow-up and the IUD was left in place. Conclusion. Asymptomatic patients, whose vaginal examinations and ultrasonography or X-ray results reveal a dislocated IUD, may benefit from conservative management. PMID:25861494

  6. Femoral head fractures: hemiarthroplasty or total hip arthroplasty?

    PubMed

    Ullmark, Gösta

    2014-10-02

    Most femoral neck fractures are osteoporotic fractures in the elderly. The one-year mortality after neck fracture in this group is 24%.For hemiarthroplasty (HA) the bipolar heads have a risk reduction for reoperation due to acetabular erosion compared with monoblock heads. Surprisingly, the bipolar head had an increased reoperation risk for dislocation, infection and for periprosthetic fracture.Total hip arthroplasty (THA) after fracture has a four-fold raised risk for dislocation compared with THA after osteoarthritis. A larger head on the same neck (head to neck ratio) results in a theoretically larger range of movement and hence less risk for dislocation. The dual mobility bearing has, theoretically, the largest range of movement and good clinical results.Functional results are better for THA compared with HA. Arthroplasty for fracture has much better results compared with arthroplasty after a failed internal fixation; the risk for reoperation is more than doubled for the latter.A Swedish hip arthroplasty register study found a 20-fold higher risk for periprosthetic fracture when comparing uncemented HA with matt cemented HA. Also a polished cemented stem had 13½-fold higher risks compared with a matt.The mortality during the first day after surgery is higher for cemented compared with uncemented arthroplasties, but lower after one week, one month and one year. Analysing the time points together resulted in no difference.A matt cemented THA with a maximum head size, maybe dual mobility, has the best results, and is also for the low-demanding elderly.

  7. The long-term outcome of 755 consecutive constrained acetabular components in total hip arthroplasty examining the successes and failures.

    PubMed

    Berend, Keith R; Lombardi, Adolph V; Mallory, Thomas H; Adams, Joanne B; Russell, Jackie H; Groseth, Kari L

    2005-10-01

    Constrained acetabular components can treat or prevent instability after total hip arthroplasty (THA). We examine long-term results of 755 consecutive constrained THA in 720 patients (1986-1993; 62 primary, 59 conversion, 565 revision, 60 reimplantation, and 9 total femur). Eighty-three patients (88 THAs) were lost before 10-year follow-up, leaving 639 patients (667 THAs) available for study. Dislocation occurred in 117 hips (17.5%), in 37 (28.9%) of 128 constrained for recurrent dislocation, and 46 (28.2%) of 163 with dislocation history. Other reoperations were for aseptic loosening (51, 7.6% acetabular; 28, 4.2% stem; 16, 2.4% combined), infection (40, 6.0%), periprosthetic fracture (19, 2.8%), stem breakage (2, 0.3%), cup malposition (1, 0.1%), dissociated insert (1, 0.1%), dissociated femoral head (1, 0.1%), and impingement of 1 broken (0.1%) and 4 (0.6%) dissociated constraining rings. Although constrained acetabular components prevented recurrent dislocation in 71.1%, they should be used cautiously, with a 42.1% long-term failure rate observed in this series. Dislocation was common despite constraint with previous history as a significant risk.

  8. Dislocation filtering in GaN nanostructures.

    PubMed

    Colby, Robert; Liang, Zhiwen; Wildeson, Isaac H; Ewoldt, David A; Sands, Timothy D; García, R Edwin; Stach, Eric A

    2010-05-12

    Dislocation filtering in GaN by selective area growth through a nanoporous template is examined both by transmission electron microscopy and numerical modeling. These nanorods grow epitaxially from the (0001)-oriented GaN underlayer through the approximately 100 nm thick template and naturally terminate with hexagonal pyramid-shaped caps. It is demonstrated that for a certain window of geometric parameters a threading dislocation growing within a GaN nanorod is likely to be excluded by the strong image forces of the nearby free surfaces. Approximately 3000 nanorods were examined in cross-section, including growth through 50 and 80 nm diameter pores. The very few threading dislocations not filtered by the template turn toward a free surface within the nanorod, exiting less than 50 nm past the base of the template. The potential active region for light-emitting diode devices based on these nanorods would have been entirely free of threading dislocations for all samples examined. A greater than 2 orders of magnitude reduction in threading dislocation density can be surmised from a data set of this size. A finite element-based implementation of the eigenstrain model was employed to corroborate the experimentally observed data and examine a larger range of potential nanorod geometries, providing a simple map of the different regimes of dislocation filtering for this class of GaN nanorods. These results indicate that nanostructured semiconductor materials are effective at eliminating deleterious extended defects, as necessary to enhance the optoelectronic performance and device lifetimes compared to conventional planar heterostructures.

  9. High-temperature discrete dislocation plasticity

    NASA Astrophysics Data System (ADS)

    Keralavarma, S. M.; Benzerga, A. A.

    2015-09-01

    A framework for solving problems of dislocation-mediated plasticity coupled with point-defect diffusion is presented. The dislocations are modeled as line singularities embedded in a linear elastic medium while the point defects are represented by a concentration field as in continuum diffusion theory. Plastic flow arises due to the collective motion of a large number of dislocations. Both conservative (glide) and nonconservative (diffusion-mediated climb) motions are accounted for. Time scale separation is contingent upon the existence of quasi-equilibrium dislocation configurations. A variational principle is used to derive the coupled governing equations for point-defect diffusion and dislocation climb. Superposition is used to obtain the mechanical fields in terms of the infinite-medium discrete dislocation fields and an image field that enforces the boundary conditions while the point-defect concentration is obtained by solving the stress-dependent diffusion equations on the same finite-element grid. Core-level boundary conditions for the concentration field are avoided by invoking an approximate, yet robust kinetic law. Aspects of the formulation are general but its implementation in a simple plane strain model enables the modeling of high-temperature phenomena such as creep, recovery and relaxation in crystalline materials. With emphasis laid on lattice vacancies, the creep response of planar single crystals in simple tension emerges as a natural outcome in the simulations. A large number of boundary-value problem solutions are obtained which depict transitions from diffusional to power-law creep, in keeping with long-standing phenomenological theories of creep. In addition, some unique experimental aspects of creep in small scale specimens are also reproduced in the simulations.

  10. Interaction of dislocations with carbon-decorated dislocation loops in bcc Fe: an atomistic study.

    PubMed

    Terentyev, Dmitry; Anento, Napoleón; Serra, Anna

    2012-11-14

    Properties of ferritic Fe-based alloys are highly sensitive to the carbon content dissolved in the matrix because interstitial carbon is known to strongly interact with lattice point defects and dislocations. As a result, the accumulation of radiation defects and its impact on the change of mechanical properties is also affected by the presence of dissolved interstitial carbon. This work contributes to an understanding of how interstitial carbon atoms influence the properties of small dislocation loops, which form directly in collision cascades upon neutron or ion irradiation and are 'invisible' to (i.e. undetectable by) standard experimental techniques applied to reveal nano-structural damage in metals. We have carried out MD simulations to investigate how the trapping of 1/2 inner product 111 dislocation loops at thermally stable carbon-vacancy complexes, known to form under irradiation, affects the interaction of these dislocation loops with dislocations in bcc Fe. We have considered loops of size 1 and 3.5 nm, which represent experimentally invisible and visible defects, respectively. The obtained results point at the strong suppression of the drag of carbon-decorated loops by dislocations. In the case of direct interaction between dislocation and carbon-decorated loops, invisible loops are found to act as obstacles whose strength is at least twice as high compared to that of undecorated ones. Additional strengthening due to the carbon decoration on the visible loops was also regularly registered. The reasons for the additional strengthening have been rationalized and discussed. It is demonstrated that carbon decoration/segregation at dislocation loops affects not only accumulation of radiation damage under prolonged irradiation but also alters the post-irradiation plastic deformation mechanisms. For the first time, we provide evidence that undetectable dislocation loops decorated by carbon do contribute to the radiation hardening.

  11. Chiropractic management of hip pain after conservative hip arthroplasty.

    PubMed

    Wisdo, Jeffrey J

    2004-09-01

    To describe a case involving postsurgical hip pain that was successfully treated with a combination of chiropractic manipulation of the lumbar and pelvic region and low-tech rehabilitation 14 months postsurgery. A 45-year-old man had pain and difficulty with walking. He was diagnosed with bilateral avascular necrosis at the femoral heads. He had successful right hip arthroplasty (HA) surgery at the time of the original diagnosis and had 2 previous surgeries to the left hip joint to treat avascular necrosis, with the latter being hip arthroplasty. He had a chief complaint of left hip pain that radiated down the lateral thigh to the knee with a "clicking" of the hip noted at end range abduction and adduction, as well as an altered gait pattern associated with dysfunction of the left hip. He was treated with chiropractic manipulative therapy of the lumbar and sacroiliac joints and a rehabilitation program that consisted of in-office and home exercise programs. The patient experienced a decrease in the pain and an improvement in the flexibility and strength that led to an improved gait pattern and decreased pain. Outcomes were measured through active range of motion comparisons and use of the Harris Hip Scale Evaluation. Treatment of hip pain through chiropractic manipulation and rehabilitation is described. The patient had increases in active ranges of motion and Harris Hip scores. Additional studies should be done to evaluate the effects of chiropractic manipulations on patient outcomes following such surgeries.

  12. Dislocation etching of rough crystal faces

    NASA Astrophysics Data System (ADS)

    Van Enckevort, W. J. P.; Smet, F.

    1988-07-01

    A model for the preferential dissolution near the outcrops of dislocations at rough (K, S or F faces above the roughening temperature) crystal faces has been developed. In contrast to F faces below the roughening transition, no lateral flow of steps from the etched dislocation centre occurs and therefore only small etch pits, either not or only barely visible by optical microscopy are expected to be formed. This was confirmed by etching of K, S and F faces of Bi 4(GeO 4) 3, KH 2PO 4 and potash alum crystals.

  13. Irreducible posterolateral elbow dislocation: a rare injury.

    PubMed

    Fenelon, Christopher; Zafar, Muhammed M; Sheridan, Gerard Anthony; Kearns, Stephen

    2016-12-30

    Posterolateral dislocation of the elbow is an injury commonly treated in the emergency department by closed reduction. Very rarely it can be irreducible and require open reduction. Only four cases of irreducible posterolateral elbow dislocation have been described in the literature over the past 50 years. We report the case of a 20-year-old man who sustained such an injury. Open reduction was performed and revealed the radial head protruding or 'buttonholing' through the lateral collateral ligament complex. This case highlights that continued closed reduction of the elbow should not be attempted, as a mechanical block to reduction can occur making reduction impossible.

  14. Elbow dislocation with complete triceps avulsion.

    PubMed

    Karuppiah, S V; Knox, D

    2014-01-01

    Radio-ulnar Fracture dislocation of the elbow is a high-energy trauma which can be associated with significant ligamentous injury in adults. We report an unusual triad of injury in a patient with avulsion injury of the triceps. This injury can be thought of as a variant of "terrible triad" with dislocation of radio-ulnar joint, radial head fracture, and medial collateral ligament injury with avulsion of the triceps. Elbow has to be stabilized with early repair of the ligaments for a successful outcome.

  15. Elbow Dislocation with Complete Triceps Avulsion

    PubMed Central

    Karuppiah, S. V.; Knox, D.

    2014-01-01

    Radio-ulnar Fracture dislocation of the elbow is a high-energy trauma which can be associated with significant ligamentous injury in adults. We report an unusual triad of injury in a patient with avulsion injury of the triceps. This injury can be thought of as a variant of “terrible triad” with dislocation of radio-ulnar joint, radial head fracture, and medial collateral ligament injury with avulsion of the triceps. Elbow has to be stabilized with early repair of the ligaments for a successful outcome. PMID:24876982

  16. Geometry of dislocated de Broglie waves

    SciTech Connect

    Holland, P.R.

    1987-04-01

    The geometrical structures implicit in the de Broglie waves associated with a relativistic charged scalar quantum mechanical particle in an external field are analyzed by employing the ray concept of the causal interpretation. It is shown how an osculating Finslerian metric tensor, a torsion tensor, and a tetrad field define respectively the strain, the dislocation density, and the Burgers vector in the natural state of the wave, which is a non-Riemannian space of distant parallelism. A quantum torque determined by the quantum potential is introduced and the example of a screw dislocated wave is discussed.

  17. Mesoscale modeling of dislocations in molecular crystals

    NASA Astrophysics Data System (ADS)

    Lei, Lei; Koslowski, Marisol

    2011-02-01

    Understanding the inelastic deformation of molecular crystals is of fundamental importance to the modeling of the processing of drugs in the pharmaceutical industry as well as to the initiation of detonation in high energy density materials. In this work, we present dislocation dynamics simulations of the deformation of two molecular crystals of interest in the pharmaceutical industry, sucrose and paracetamol. The simulations calculate the yield stress of sucrose and paracetamol in good agreement with experimental observation and predict the anisotropy in the mechanical response observed in these materials. Our results show that dislocation dynamics is an effective tool to study plastic deformation in molecular crystals.

  18. Rotator Cuff Tear Consequent to Glenohumeral Dislocation.

    PubMed

    Gilotra, Mohit N; Christian, Matthew W; Lovering, Richard M

    2016-08-01

    The patient was a 21-year-old collegiate running back who was tackled during a football game and sustained a posterior glenohumeral dislocation. He was referred to an orthopaedist and presented 3 weeks after the injury, and, following examination, further imaging was ordered by the orthopaedist due to rotator cuff weakness. Magnetic resonance imaging showed a complete tear of the supraspinatus and infraspinatus, as well as a posterior Bankart lesion, a subscapularis tear, and a dislocation of the biceps long head tendon into the reverse Hill-Sachs lesion. J Orthop Sports Phys Ther 2016;46(8):708. doi:10.2519/jospt.2016.0413.

  19. Total hip replacement in young adults with hip dysplasia

    PubMed Central

    2011-01-01

    Background and purpose Dysplasia of the hip increases the risk of secondary degenerative change and subsequent total hip replacement. Here we report on age at diagnosis of dysplasia, previous treatment, and quality of life for patients born after 1967 and registered with a total hip replacement due to dysplasia in the Norwegian Arthroplasty Register. We also used the medical records to validate the diagnosis reported by the orthopedic surgeon to the register. Methods Subjects born after January 1, 1967 and registered with a primary total hip replacement in the Norwegian Arthroplasty Register during the period 1987–2007 (n = 713) were included in the study. Data on hip symptoms and quality of life (EQ-5D) were collected through questionnaires. Elaborating information was retrieved from the medical records. Results 540 of 713 patients (76%) (corresponding to 634 hips) returned the questionnaires and consented for additional information to be retrieved from their medical records. Hip dysplasia accounted for 163 of 634 hip replacements (26%), 134 of which were in females (82%). Median age at time of diagnosis was 7.8 (0–39) years: 4.4 years for females and 22 years for males. After reviewing accessible medical records, the diagnosis of hip dysplasia was confirmed in 132 of 150 hips (88%). Interpretation One quarter of hip replacements performed in patients aged 40 or younger were due to an underlying hip dysplasia, which, in most cases, was diagnosed during late childhood. The dysplasia diagnosis reported to the register was correct for 88% of the hips. PMID:21434808

  20. Conus hip prosthesis.

    PubMed

    Wagner, H; Wagner, M

    2001-01-01

    50 years ago, prosthetic replacement of the hip joint ushered in a new epoch in orthopaedics. Total hip replacement made it possible to remove a severely diseased, painful hip and restore normal function and a normal quality of life to the afflicted patient. The early results of total hip replacement are almost all spectacular and hip replacement has become the most successful type of orthopaedic surgery. These good results using an approach that was technically relatively simple resulted in a temptation to implant prosthetic hip joints with ever increasing frequency in ever younger patients. This led to the emergence of new problems, which were not so clearly recognised at the outset: it emerged that the stability of prosthetic hip joints was of limited duration. This had the following consequence: If a total hip prosthesis is implanted in an elderly person whose remaining life-expectancy is shorter than the longevity of the prosthesis, hip replacement is a life-long solution. We can therefore say that, for a patient who has only 10 to 15 years left to live, their hip problem is solved by total hip replacement. For young people, who still have a long life expectancy in front of them, it is different. They will experience failure of the artificial joint and require further surgery. The commonest and most important type of failure in total hip prostheses is aseptic loosening, which is associated with resorption of bone at the site of the prosthesis. The cause of this phenomenon has only gradually been recognised in the course of the years. Initially, the unanimous opinion was that the methacrylate cement, used to fix the components of the prosthesis in the bone, was the definitive cause of aseptic loosening because fissures and fractures of the cement were almost always found during surgical revision of loosened joints. There was talk of "cement disease" and great efforts were made to improve the quality of the cement and the cementing technique. Moreover, even