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At least 397 records · Page 22Linked to original sources
PubMed2003

Radiographic analysis of bone defects in chronic anterior shoulder instability.

PURPOSE: To describe the incidence of bony lesions accompanying chronic anterior shoulder instability using fluoroscopically controlled radiography. TYPE OF STUDY: Case series of radiographic findings of patients with chronic anterior shoulder instability. METHODS: Radiographs of 160 shoulders in 156 patients with recurrent anterior shoulder instability were retrospectively evaluated; 132 shoulders had experienced recurrent dislocations, 18 shoulders had experienced recurrent subluxations, and 10 shoulders showed evidence of anterior instability at arthroscopy despite no reported history of instability. Fluoroscopically controlled radiographic views included an anteroposterior view with the humeral head in 3 rotations and a glenoid profile view with a comparison view of the contralateral shoulder. RESULTS: A humeral impaction fracture was identified on the anteroposterior radiographs in 117 of 160 shoulders (73.1%). The glenoid profile view showed an osseous lesion of the glenoid in 126 of 160 shoulders (78.8%). The anteroposterior radiograph showed an osseous lesion of the glenoid in an additional 13 shoulders (8.2%). Overall, an osseous lesion, either humeral or glenoid, was identified in 152 of 160 shoulders (95.0%). CONCLUSIONS: This study shows the frequent presence of bony lesions in patients with anterior shoulder instability.

Adolescent↗
PubMed2004

The role of genomic instability in the pathogenesis of squamous cell carcinoma of the head and neck.

Measurements of genomic instability, or identification of genes responsible for instability, may potentially be used as molecular markers to predict disease course and response to therapy. Other possible applications include use of genomic instability measurements, or genes, as tools to screen for primary or recurrent disease. Methodologies for detection of genetic mutations in saliva, blood, and sputum have already been described[61,62]. Brennan et al [63] have described a molecular technique for analyzing histopathologically negative margins and lymph nodes for the presence of p53 gene mutation. This study showed that a positive molecular margin significantly predicted disease recurrence. The recognition that HNSCC is a genetically heterogeneous disease represents a major step toward developing an understanding of its underlying genetic basis. To develop an insight into this genetically heterogeneous disease, investigators must not only focus their efforts on specific head and neck disease sites. Laser-capture microdissection represents a powerful tool for isolating very specific cell populations from tumors [64]. Leethanakul et al[65] performed laser-capture microdissection on oral cavity SCC to construct stage-specific cDNA libraries. Sequencing of 96 clones from each of the six libraries constructed suggested the existence of 132 novel genes, which may play a role in the pathogenesis of HNSCC. The current literature suggests that many individuals diagnosed withHNSCC are genetically predisposed to developing malignancy because of some inherent deficiency of their capacity to maintain their genome in the presence of environmental stressors. Head and neck cancers are highly heterogeneous tumors and exhibit a wide variety of forms of genomic instability. Thus, genomic instability may be viewed as a fundamental force driving head and neck tumorigenesis and evolution. Future study of the specific genetic mechanisms that underlie genomic instability in the HNSCCpatient population is needed. It is only through study of this fundamental force that drives the development of these tumors that clinicians may gain the insight required to develop new diagnostic and therapeutic modalities to benefit the HNSCC patient population as a whole.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Arthroscopic treatment of multidirectional instability.

Multidirectional instability of the shoulder, described by Neer and Foster, has been treated surgically with the inferior capsular shift procedure. The small number of reports on mid-term outcomes indicate that good to excellent results have been obtained in 75% to 100% of cases. Arthroscopic treatment of multidirectional instability has been previously described. The purpose of this study was to review the results of the arthroscopic capsular shift procedure with a minimum follow-up of 2 years. A retrospective study was performed on 25 patients who underwent an arthroscopic capsular shift performed with the transglenoid technique between January 1990 and December 1993. All patients had earlier not responded to an extensive course of physical therapy. Excluded from the study were patients who had undergone a previous arthroscopic capsular shift or any other procedure, arthroscopic or open, for the shoulder. Average patient age was 26.4 years. There were 20 male and 5 female patients. Sixteen of the affected shoulders involved the dominant extremity. All patients had a history of asymptomatic subluxation that slowly progressed to symptomatic subluxation. Eleven patients had a history of dislocation. Thirteen patients were athletes who were symptomatic in their chosen sport, whereas the other patients were symptomatic in activities of daily living. All patients were examined while they were under anesthesia and had positive results on the sulcus test in abduction with associated anterior instability, posterior instability, or both. Follow-up evaluation was performed with patient interview and examination. All 25 patients were available for follow-up, which occurred an average of 60 months (range 36 to 80 months) after operation. Three patients had episodes of instability after the operation. The average Bankart score was 95 (range of 50 to 100). All but 1 patient had regained full symmetric range of motion by follow-up. Twenty-one (88%) patients had a satisfactory result according to the Neer system. Results of treatment with the arthroscopic capsular shift procedure for multidirectional instability of the shoulder appear to be comparable to those of the open inferior capsular shift.

Adolescent↗
PubMed2003

Medial ankle instability.

Medial instability is suspected on the basis of a patient's ankle feeling like it is "giving way," especially medially, when walking on uneven ground, downhill, or down stairs, pain at the anteromedial aspect of the ankle, and sometimes pain in the lateral ankle, especially during dorsiflexion of the foot. A history of a chronically unstable feeling that is manifested by recurrent injuries with pain, tenderness, and sometimes bruising over the medial and lateral ligaments, is considered to indicate combined medial and lateral instability that is believed to result in rotational instability of the talus in the ankle mortise. Pain on the medial gutter of the ankle and a valgus and pronation deformity of the foot are hallmarks of the disorder. The deformity typically can be corrected by the activation of the posterior tibial muscle. In contrast to stress radiographs, arthroscopy is a helpful diagnostic tool in verifying medial instability; it proved that the lateral ankle ligaments also can be involved. The treatment for symptomatic medial instability of the ankle might include reconstruction of all involved ligaments at the medial, and, if necessary, the lateral ankle. In the case of progressed foot deformity or bilateral long-standing valgus and pronation deformity of the foot, an additional calcaneal lengthening osteotomy might be considered. A classification of the instability into three types has been helpful for determining surgical treatment and the after treatment. This treatment concept provides high patient satisfaction and reliable clinical results.

Ankle Injuries↗
PubMed2004

Disruption of beta-catenin pathway or genomic instability define two distinct categories of liver cancer in transgenic mice.

BACKGROUND & AIMS: Human liver cancer can be divided into 2 categories that are characterized by activation of beta-catenin and genomic instability. Here we investigate whether similar categories exist among 5 transgenic models of liver cancer, including c-myc, transforming growth factor-alpha, E2F-1, c-myc/transforming growth factor-alpha, and c-myc/E2F-1 mice. METHODS: The random amplified polymorphic DNA method was used to assess the overall genomic instability, and chromosomal loci affected by genomic alterations were determined by microsatellite analysis. beta-Catenin mutations and deletions were analyzed by polymerase chain reaction and sequencing screening. Cellular localization of beta-catenin and expression of alpha-fetoprotein, a prognostic marker of hepatocellular carcinoma, were investigated by immunohistochemistry. RESULTS: Liver tumors from the transgenic mice could be divided into 2 broad categories characterized by extensive genomic instability (exemplified by the c-myc/transforming growth factor-alpha mouse) and activation of beta-catenin (exemplified by the c-myc/E2F-1 mouse). The c-myc/transforming growth factor-alpha tumors displayed extensive genomic instability with recurrent loss of heterozygosity at chromosomes 1, 2, 4, 6, 7, 9, 12, 14, and X and a low rate of beta-catenin activation. The genomic instability was evident from the early dysplastic stage and occurred concomitantly with increased expression of alpha-fetoprotein. The c-myc/E2F-1 tumors were characterized by a high frequency of beta-catenin activation in the presence of a relatively stable genome and low alpha-fetoprotein levels. CONCLUSIONS: We have identified 2 prototype experimental models, i.e., c-myc/transforming growth factor-alpha and c-myc/E2F-1 mice, for the 2 categories of human hepatocellular carcinoma characterized by genomic instability and beta-catenin activation, respectively. These mouse models will assist in the elucidation of the molecular basis of human hepatocellular carcinoma.

Animals↗
PubMedDate not supplied

[Value of glenoid osteotomy in treatment of posterior shoulder instability].

UNLABELLED: Purpose of this retrospective study was to evaluate the midterm results of glenoid osteotomy in the treatment of posterior instability and furthermore to evaluate the relevance of etiopathogenesis on the outcome. METHOD: Between Jan. 83 and May 94 32 patients underwent surgery due to posterior instability. Retrospectively these patients were classified based on their etiopathogenesis. 28 patients could be reexamined clinically and radiologically after and average of 4.85 years, of which 21 were treated with a glenoid osteotomy. For evaluation the Constant-Murley and the Rowe-Score were used. RESULTS: The Constant-Score showed 82,2% and the Rowe-Score 71,5% good or excellent results. Evaluation of glenoid osteotomy demonstrated for the patients with atraumatic genesis an excellent result in 76.9% with a recurrence rate of only 15.4%. On the other hand patients with traumatic instability showed a recurrence rate of 50%. The radiologic assessment demonstrated degenerative changes in nearly 30% of cases treated with glenoid osteotomy. CONCLUSION: This study shows that glenoid osteotomy can provide good result in the surgical treatment of posterior atraumatic instability. For treatment of traumatic instability, however, glenoid osteotomy is not the procedure due to high recurrence and arthrosis rates. RELEVANCE: Posterior glenoid osteotomy should be reserved for patients with atraumatic posterior instability combined with an increased retroversion angle of the glenoid especially because of the high rate of arthrosis.

Adolescent↗
PubMed2003

Genomic instability and radiation.

Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed.

Genes, p53↗
PubMed2005

Comprehensive measurement of chromosomal instability in cancer cells: combination of fluorescence in situ hybridization and cytokinesis-block micronucleus assay.

Most tumors show abnormal karyotypes involving either chromosome rearrangements and/or aneuploidies. The aim of our study is to measure the rate of both structural and numerical chromosome instability in two colorectal cancer cell lines: HCT116, and SW480 and its single subclones. To determine structural instability, we measured the nonclonal chromosome alterations of the last cell division by means of multicolor-fluorescence in situ hybridization (FISH). To quantify numerical instability, we used centromere-specific DNA probes to simultaneously detect chromosome loss and nondisjunctional events in binucleated cells obtained by cytokinesis-block micronucleus assay (CBMN). After clonal episodes, the structural chromosome instability rate increased significantly, confirming the large contribution of structural rearrangements to the heterogeneity of cancer cells. On the other hand, the aneuploidy rate was high and conserved in both the parental SW480 cell line and its subclones. The ability to differentiate chromosome loss and nondisjunction by the CBMN assay allowed us to conclude that no significant differences were detected among these events. Analysis of nucleoplasmic bridges, micronuclei, and nuclear blebs also demonstrated the differences among the structural instability rates of the parental cell line and its subclones. Overall, our results demonstrate the prevalence of structural over numerical chromosome instability in the subclones when comparing them with their parental cell line, confirming the contribution of ongoing chromosomal reorganizations in the generation of tumor cell heterogeneity.

Aneuploidy↗
PubMed1995

Current management of cervical spine instability.

Instability of the cervical spine is a frequently occurring problem in a number of rheumatologic conditions. The importance of recognizing cervical instability lies in its close association with severe, sometimes irreversible, neurologic compromise that can lead to paralysis or even death. Operative stabilization of cervical instability prior to the onset of irreversible neurologic changes has been advocated. The problem, however, has been that no reliable method has accurately predicted which patients with cervical instability are at risk for spinal cord compression. It has been determined in recent studies that specific measurements of radiographic instability are strongly associated with worsening neurologic compromise. These measurements assess the space available for the spinal cord, and recommendations can be made for surgical stabilization in patients with cervical instability, prior to the onset of neurologic changes.

Arthritis, Rheumatoid↗
PubMed1998

Flexion instability after primary posterior cruciate retaining total knee arthroplasty.

Between 1990 and 1995, 25 painful primary posterior cruciate ligament retaining total knee arthroplasties were revised for flexion instability. These patients shared typical clinical presentations that included a sense of instability without frank giving way, recurrent knee joint effusion, soft tissue tenderness involving the pes anserine tendons and the retinacular tissue, posterior instability of 2+ or 3+ with a posterior drawer or a posterior sag sign at 90 degrees flexion, and above average motion of their total knee arthroplasty. The primary total knee arthroplasty was performed for osteoarthritis in 23 patients and rheumatoid arthritis in two patients. There were 13 male and 12 female patients and their mean age was 65 years (range, 35-77 years). Before the revision operation, Knee Society knee scores averaged 45 points (range, 17-68 points) and function scores averaged 42 points (range, 0-60 points). Twenty-two of the knee replacements were revised to posterior stabilized implants and three underwent tibial polyethylene liner exchange only. Nineteen of the 22 knee replacements revised to a posterior stabilized implant were improved markedly after the revision surgery. Only one of three knee replacements that underwent tibial polyethylene exchange was improved. After the revision for flexion instability, Knee Society knee scores averaged 90 points (range, 82-99 points) and function scores averaged 75 points (range, 45-100 points) for the 20 knees with a successful outcome. This study suggests that flexion instability can be a cause of persistent pain and functional impairment after posterior cruciate ligament retaining total knee arthroplasty. A revision operation that focuses on balancing the flexion and extension spaces, in conjunction with a posterior stabilized knee implant, seems to be a reliable treatment for symptomatic flexion instability after posterior cruciate retaining total knee arthroplasty.

Adult↗
PubMed2004

Dynamic upper limb proprioception in multidirectional shoulder instability.

The ability of subjects with multidirectional shoulder instability to use proprioception to complete a series of upper limb repositioning tasks was investigated. Twelve subjects with multidirectional instability and 12 control subjects were blindfolded and instructed to use proprioception to reproduce a self-selected target position as accurately as possible. Subjects completed 10 repetitions for each limb using three distinct upper limb movements: overhead reaching, scapular plane pointing, and humeral external rotation with abduction. A three-dimensional video motion analysis system tracked limb position and determined spatial hand position error. Subjects with multidirectional shoulder instability showed significantly greater hand position error than control subjects. No hand position error differences were found between the symptomatic and the asymptomatic limbs of subjects in the instability group. Inter-repetition error for subjects in both groups improved significantly during the first three movement cycles. These results suggest that after movement initiation, dynamic proprioception was a factor in improving hand position accuracy in both groups, but to a lesser degree in subjects with multidirectional instability. Consequently, subjects with multidirectional instability may have a reduced capacity to use proprioception to refine and control the motor output of the upper limb.

Adult↗
PubMed1989

Analysis of cervical instability resulting from laminectomies for removal of spinal cord tumor.

Thirty-four patients with cervical cord tumor were followed in order to investigate the incidence of postoperative deformity or instability after laminectomies. Seven cases (20%) presented cervical instability, including three cases that required spinal fusion. Analysis of these cases revealed the identification of some risk factors that are involved in the pathogenetic mechanism of cervical instability, which are: age at operation, preoperative curvature in neutral position, number of removed laminas, C2 laminectomy, and destruction of facet joints. The number of these risk factors present in each case was shown to be directly related to the incidence of cervical instability. Patients who had not developed instability demonstrated 1.2 factors on average, while patients who had developed instability showed a mean of 2.5 factors. Patients who had additionally required spinal fusion presented 3 risk factors, including C2 laminectomy and destruction of facet joints.

Adult↗
PubMed1999

Traumatic instabilities of the cervical spine caused by high-speed axial compression in a human model. An in vitro biomechanical study.

STUDY DESIGN: Traumatic injury of the cervical spine was produced on human cadavers and evaluated with instability tests and radiographs. OBJECTIVE: To relate traumatic injuries of the cervical spine to instability and patterns of traumatic injury to different levels of impact energy. SUMMARY OF BACKGROUND DATA: Data from young human cadavers are rare in traumatic models of the cervical spine, and instabilities caused by axial compression with different impacts remain unknown. METHODS: Fourteen cervical spine specimens (C2-C4) obtained from fresh human cadavers were divided evenly into two groups and subjected to axial compressive impact with 30 J and 50 J impact energy, respectively. Pure moments in flexion-extension, left/right lateral bending, and left/right axial rotation were applied to each specimen before and after trauma. The maximum moment was 2.0 Nm in each case. Ranges of motion and neutral zones were measured using stereophotogrammetry. RESULTS: Ranges of motion and neutral zones for both groups increased after trauma. No bony injury was observed on the radiographs after trauma with 30 J, but motions increased significantly in flexion, extension, and axial rotation. All specimens showed bony injuries after trauma with 50 J, whereas motions continued to increase significantly in all directions. The relative neutral zone values were larger than the corresponding range of motion values, except in flexion-extension after trauma with 50 J. CONCLUSIONS: The injury patterns of the cervical spine were associated with impact energy, and a high level of impact energy could produce either three-column injury or anterior middle-column injury. Instabilities of the cervical spine caused by compressive trauma increased with the level of impact energy. The neutral zone was more sensitive than the range of motion in representing spinal instability, whereas instability testing was more sensitive than radiographs in evaluating traumatic injury of cervical spine.

Adult↗
PubMed2001

Surgical treatment of adjacent instability after lumbar spine fusion.

STUDY DESIGN: This study is a retrospective review of 39 patients with previous instrumented lumbar fusion who underwent secondary spine surgery for lumbar adjacent instability. To the authors' knowledge, this is the largest study of surgical treatment of lumbar adjacent instability in the literature to date. OBJECT: This study evaluated the feasibility of adjacent instability treated with medial facetectomy, fusion with autologous bone grafting, and pedicle screw instrumentation. SUMMARY OF BACKGROUND DATA: The surgical treatment of adjacent instability has seldom been discussed. Revision spine fusions are challenged by high pseudarthrosis rates. METHODS: Thirty-nine patients with previous lumbar fusion underwent second lumbar spine surgery for adjacent instability. All were treated with autogenous posterolateral arthrodesis and transpedicle screw fixation in addition to decompressive laminectomy. Medical records, radiographs, and pain scores were obtained. RESULTS: The clinical results were excellent or good in 76.9% of patients, and the radiographic fusion was successful in 37 (94.9%) of patients. Flat back was noted in 8 (20.5%) of patients. In 5 patients (12.8%), neighboring segment breakdown again developed, and 2 of those patients underwent a third lumbar fusion. Dural tear during operation occurred in 2 patients. One patient experienced cauda equina syndrome but recovered bladder function 1 month later. CONCLUSION: Autogenous posterolateral arthrodesis combined with pedicle screw fixation led to successful radiologic and clinical outcome in patients with lumbar adjacent instability. Adequate decompression of the adjacent stenosis requires medial facetectomy, thus preventing aggressive nerve root manipulation and reducing the incidence of dural tear.

Aged↗
PubMed2002

Preoperative instability does not influence the clinical outcome in patients with cervical spondylotic myelopathy treated with expansive laminoplasty.

Sixty-seven patients with cervical spondylotic myelopathy treated with expansive laminoplasty were retrospectively reviewed at a minimum 2-year follow-up. This study was designed to evaluate whether preoperative instability influences the clinical outcome in patients with cervical spondylotic myelopathy treated with laminoplasty without spinal fusion. Patients with preoperative instability were older and had shorter durations of symptoms prior to surgery than those without the instability. There were no significant differences in prevalence of axial symptoms, neurologic recovery, or radiologic findings between patients with and without preoperative cervical instability. At follow-up, the cervical range of motion was limited to 43.5% of the preoperative range, and no cervical instability was observed in any patients. Preoperative instability does not influence the clinical outcome and can be ignored if expansive laminoplasty is indicated for patients with cervical spondylotic myelopathy.

Adult↗
PubMed2003

Infection after shoulder instability surgery.

Currently, there are no reported series on the outcome of patients treated for infection after shoulder instability surgery. Therefore, the purpose of this study was to review patients who were treated for infection after shoulder instability surgery at our institution between 1980 and 2001 to determine the functional outcome and organisms responsible for infection. During this period, six patients were treated for infection after shoulder instability surgery. Three patients had an early postoperative infection, presenting 6 weeks or less from the time of instability surgery. Three patients had a late infection, presenting 8 months or greater from the time of surgery. Each of the three patients with a late infection had a sinus leading to a retained nonabsorbable suture. None of the six patients have had recurrent shoulder instability. Three patients had a polymicrobial infection and three patients had single organisms. Infection may be acute or significantly delayed from the time of the instability procedure. Additionally, among patients with late infection, there should be a high degree of suspicion for a nidus of infection surrounding nonabsorbable sutures.

Adult↗
PubMed2004

Anterior shoulder instability modifies glenoid subchondral bone density.

Subchondral bone mineralization is used as a morphologic marker for individual stress distribution of joints and therefore may help to distinguish variations of glenohumeral contact. Therefore, an in vivo analysis was done to evaluate glenoid stress distribution in anterior glenohumeral instability by computed tomography osteoabsorptiometry. Patients with recurrent anterior glenohumeral dislocation, seven of posttraumatic and six of atraumatic origin, and an intact rotator cuff were grouped retrospectively and compared with healthy, age-matched shoulder specimens from cadavers (n = 13). Glenoid subchondral bone mineralization, including those in all patients with anterior glenohumeral instability, indicated a more anterior and inferior stress distribution compared with stable shoulders. The position of the anterior glenoid density maximum had shifted anteriorly and inferiorly whereas the position of the posterior maximum had shifted anteriorly. Analyzing results on the basis of cause, in posttraumatic instabilities, the shift of the anterior maximum mainly was anterior and in atraumatic instabilities, it mainly was inferior. Individual glenoid stress distribution in anterior glenohumeral instability can be assessed objectively by computed tomography osteoabsorptiometry. The shift of the density maxima corresponded with anterior and inferior directions of humeral head displacement, whereas the degree of changes varied according to the cause of glenohumeral instability.

Absorptiometry, Photon↗
PubMed2004

Cervical instability in Sotos syndrome: a case report.

STUDY DESIGN: A case report on cervical instability detected in a patient with Sotos syndrome, along with a review of the literature on Sotos syndrome and associated spinal findings. OBJECTIVE: To present the case of a patient with a C3-C4 anterolisthesis occurring in the setting of Sotos syndrome and explore a possible association between the two. SUMMARY OF BACKGROUND DATA: Sotos syndrome, a rare overgrowth syndrome with slightly more than 300 cases reported in the English literature to date, is characterized by a unique constellation of symptoms and signs including musculoskeletal findings such as scoliosis, pes planus, generalized ligamentous laxity, and increased growth rates. Cervical instability as part of this syndrome is unreported and rarely presents as a C3-C4 anterolisthesis. METHODS: A case report detailing the evaluation and treatment of a cervical instability in a 3-year-old with Sotos syndrome. RESULTS: A previously unreported cervical spine instability in Sotos syndrome is described. The patient underwent a posterior spinal fusion of C3 and C4 to avoid complications from the instability. The surgery achieved good results. CONCLUSION: We outline a possible connection between Sotos syndrome and cervical instability, which may be associated with the unique features of this syndrome including ligamentous laxity or macrosomia and/or with unrecognized injury. Awareness of this occurrence is important for enhancing early detection and correction of this condition.

Abnormalities, Multiple↗