Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Joint Instability”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed2000

Is there increased intervertebral mobility in isthmic adult spondylolisthesis? A matched comparative study using roentgen stereophotogrammetry.

STUDY DESIGN: By roentgen stereophotogrammetric technique, the intervertebral mobility of the spondylolytic segment in eight patients was measured and compared with the mobility of eight nonspondylolytic patients matched according to sex, afflicted segment, and grade of disc degeneration. OBJECTIVES: To compare the intervertebral mobility of a spondylolytic segment with the mobility of a segment without spondylolysis in adult patients with back pain. SUMMARY OF BACKGROUND DATA: Evidenced by the resulting olisthetic deformity and supported by the outcome from prior investigations, spondylolysis is assumed to induce spinal segmental instability/hypermobility. METHODS: After percutaneous application of tantalum indicators for roentgen stereophotogrammetric technique, the intervertebral translations of the spondylolytic fifth lumbar vertebra were measured in eight adult patients with low back pain and low-grade olisthesis. Eight other patients without spondylolysis but with low back pain presumably on degenerative basis were chosen for comparison and had an identical measuring procedure using roentgen stereophotogrammetric technique. The two groups were matched in pairs according to sex, afflicted segment, and grade of disc degeneration. RESULTS: No significant difference was registered considering the intervertebral mobility for matched pairs in the two groups neither along the sagittal nor the vertical axis. The transverse translations were mostly negligible in both groups. CONCLUSION: The spondylolytic defect in pars interarticularis does not cause permanent instability/hypermobility detectable in the adult patient with low back pain and low-grade olisthesis.

Adult↗
PubMed2001

Morphologic changes in the lumbar intervertebral foramen due to flexion-extension, lateral bending, and axial rotation: an in vitro anatomic and biomechanical study.

STUDY DESIGN: A biomechanical and anatomic study with human cadaveric lumbar spine. OBJECTIVES: The purpose of this study is to examine the morphologic changes in the intervertebral foramen during flexion, extension, lateral bending, and axial rotation of the lumbar spine and to correlate these changes with the flexibility of the spinal motion segments. SUMMARY OF BACKGROUND DATA: Previous studies showed morphologic changes in the intervertebral foramen during flexion and extension; however, those changes during lateral bending and axial rotation were not well known. METHODS: There were 81 motion segments obtained from 39 human cadaveric lumbar spines (mean age 69 years). The motion segments were imaged with CT scanner with 1-mm thick consecutive sections. For biomechanical testing each motion segment was applied with incremental pure moments of flexion, extension, lateral bending, and axial rotation. Rotational movements of the motion segment were measured using VICON cameras. After application of the last load, the specimens were frozen under load, and then CT was performed with the same technique described above. Six parameters of the intervertebral foramen were measured, including foraminal width (maximum and minimum), foraminal height, disc bulging, thickness of ligamentum flavum, and cross-sectional area of the foramen. RESULTS: Flexion increased the foraminal width (maximum and minimum), height, and area significantly while significantly decreasing the disc bulging and thickness of ligamentum flavum (P < 0.05). However, extension decreased the foraminal width (maximum and minimum), height, and area significantly. Lateral bending significantly decreased the foraminal width (maximum and minimum), height, and area at the bending side, whereas lateral bending significantly increased the foraminal width (minimum), height, and area at the opposite side of bending. Likewise, axial rotation decreased the foraminal width (minimum) and area at the rotation side significantly while significantly increasing the foraminal height and foraminal area at the opposite side. The percent change in the foraminal area was found significantly correlated with the amount of segmental spinal motion except for the extension motion. CONCLUSIONS: This study showed that the intervertebral foramen of the lumbar spine changed significantly not only on flexion-extension but also on lateral bending and axial rotation. The percent change in cross-sectional foraminal area was correlated with the amount of segmental motion except for extension motions. Further studies are needed to assess the morphologic changes in the intervertebral foramen in vivo and to correlate clinically.

Adult↗
PubMed2002

In vitro biomechanical studies of an anterior thoracolumbar implant.

After L1 corpectomy in T11-L3 human cadaveric spine, anterior thoracolumbar instrumentation with strut grafting restores spinal stability. T12-L2 angular rotation was measured in response to moments of 0.0, 1.5, 3.0, 4.5, and 6.0 Nm in flexion, extension, lateral bending, and axial rotation, respectively. The spines were tested: 1) intact; 2) after partial L1 corpectomy, grafting, and instrumentation (Profile plate, DePuy-AcroMed, Raynham, MA), with the wooden dowel graft screwed to the plate; 3) without graft screw fixation; and 4) after flexion-extension cyclic fatiguing for 5000 cycles at a load of +/-3.0 Nm. Before and after fatiguing, the instrumented spine was significantly (p <or= 0.05) stiffer than the intact spine in flexion, extension, and right and left lateral bending but not in axial rotation. There were no significant differences between the constructs with or without graft-to-plate fixation before or after fatigue. The instrumented spines were more rigid in bending away from the implant than bending toward the implant. Anterior spinal instrumentation with the Profile implant augments stiffness in the sagittal and coronal planes but not in the axial plane. Although graft-to-plate fixation may prevent graft migration into the canal, it does not contribute to spinal rigidity.

Biomechanical Phenomena↗
PubMed2004

Influence of articular geometry on prosthetic wrist stability.

Ellipsoid and toroid-shaped articulations for total wrist prostheses were evaluated using computer modeling and laboratory experiments. An ellipsoidal design was found to accommodate greater width of the concave proximal component, resulting in better capture and prosthetic stability than a toroid shape. An ellipsoid articulation also provides greater contact area through the available arc of motion. An ellipsoidal articulation is a reasonable design for total wrist arthroplasty.

Computer Simulation↗
PubMed2004

Assessment of articular displacement of distal radius fractures.

Intraarticular step and gap displacements represent the most common indication for surgical treatment of distal radius fractures. Most often, treatment decision making relies only on good-quality plain radiographs taken before and after reduction with measurement accuracy maximized by using the longitudinal axis method. When plain radiographs alone prove insufficient, CT scans or tomograms will significantly improve interobserver and intraobserver reliability of measurements, especially when evaluated using the arc method. Tomography is an effective method for postoperative evaluation of fractures immobilized in splints or casts. The role of MRI in assessing intraarticular distal radius fractures is limited to confirming injuries to carpal ligaments or the triangular fibrocartilage complex. Intraoperatively, we use fluoroscopy to obtain 30 degrees cephalad posteroanterior views and as 22 degrees lateral views to best observe articular surface reduction. Our current operative indications include fractures with radiocarpal or distal radioulnar joint step or gap deformities greater than 1-2 mm, gross distal radioulnar joint instability, or those with extensive metaphyseal comminution rendering them particularly unstable after closed reduction. In general, we tend to lean toward operative fixation in younger, more active patients.

Arthroscopy↗
PubMed2006

Lumbar total disc arthroplasty utilizing the ProDisc prosthesis in smokers versus nonsmokers: a prospective study with 2-year minimum follow-up.

STUDY DESIGN: Prospective nonrandomized clinical series. OBJECTIVES: To evaluate the efficacy of ProDisc lumbar artificial disc replacement (ADR) in smokers versus nonsmokers. SUMMARY OF BACKGROUND DATA: Smoking is a negative predictor in fusion surgery. To date, a prospective study of the treatment of incapacitating discogenic low back pain using ADR in smokers versus nonsmokers has not been described. METHODS: A prospective analysis was performed on 104 patients with disabling discogenic low back pain treated with single-level lumbar ProDisc total disc arthroplasty. Smokers and nonsmokers were assessed before surgery and after surgery using patient satisfaction, Oswestry, and Visual Analog Scores. Additionally, preoperative and postoperative neurologic, radiographic, and pain medication assessments were performed at similar postoperative intervals. RESULTS: Oswestry, Visual Analog Scores, and patient satisfaction scores revealed statistical improvement beginning 3 months after surgery and were maintained at minimum 2-year follow-up. Patient satisfaction scores were higher in smokers (94%) than in nonsmokers (87%) at 2-year follow-up (P = 0.07). Radiographic analysis revealed an affected disc height increase from 4 mm to 13 mm (P < 0.05) and an affected disc motion from 3 degrees to 7 degrees (P < 0.05). No cases of loosening, dislodgment, mechanical failure, infection, or fusion of the affected segment occurred. CONCLUSIONS: The results of our study indicate that smokers do equally well compared with nonsmokers when ProDisc ADR is used in the treatment of debilitating lumbar spondylosis. Patient outcome and radiographic scores showed significant improvement compared with preoperative levels. Although not evident in our series, additional surveillance for intraoperative and postoperative vascular spasm and occlusion may be warranted in smokers.

Adolescent↗
PubMed1985

Age changes in the flexibility of Down's syndrome children.

The association between Down's syndrome (DS) and joint hyperflexibility is well documented. However, objective information concerning developmental expectations for flexibility in DS children is lacking. This investigation used goniometric techniques to examine the changes in flexibility with growth and maturation in 30 DS children aged 5, 10 and 15 years and compared them with 30 normal controls. Flexibility declined consistently with age in the DS children and in the controls, and although the DS children were more flexible than their control counterparts at each age, the magnitude of change over the whole age range was parallel in both groups of children suggesting some similarity in mechanisms controlling the maturation of joint tissues. The greatest reduction in flexibility occurred in the hip and ankle joints, and in the elbow and knee hyperextension. A trend was evident for the largest reduction in measurements to occur between 5 and 10 years in the DS children compared with a consistent or later reduction in the controls. It is postulated that this may be attributable to the improvement in generalized muscular hypotonia expected during this age period, or to differences in the rate of maturation of joint structures in the early years, caused by the effects of the syndrome on the intrinsic mechanisms regulating the growth of joints.

Adolescent↗
PubMed1987

Mandibular border positions and their relationships with peripheral joint mobility.

Peripheral joint mobility was assessed in a group of fifty-one dental students using a modification of the Carter and Wilkinson Index. Mandibular border positions were measured both actively and passively with the aid of a millimetre ruler. The purpose of the investigation was to study possible relationships between generalized joint (hyper-)mobility and (hyper-)mobility of the temporomandibular joints. Only a few weak correlations were found between the mandibular border position measurements (active and passive mouth opening, active and passive, left and right, laterotrusions and active protrusion) and the peripheral joint mobility measurements. Differences between the sexes were illustrated in peripheral joint mobility with females showing a greater joint mobility than males, especially when only the passively measured joints were considered. The mandibular border positions were significantly correlated with each other (P less than 0.05-P less than 0.001) for the males, but few and then only weak relationships between these measurements could be found for the females in this group. The concept of temporomandibular joint 'end-feel' in relation to joint mobility is discussed.

Adult↗
PubMed1992

Maximum jaw opening capacity in adolescents in relation to general joint mobility.

Mandibular jaw opening was related with general joint mobility in a non-patient adolescent group. The angular rotation of the mandible at maximum jaw opening was slightly larger in females than in males and significantly larger in hypermobile individuals. No significant relationship between linear measuring of maximal mandibular opening capacity and peripheral joint mobility was found either at active (AROM) or at passive range of mandibular opening (PROM). PROM was strongly correlated to the mandibular length. Clinical signs in the great jaw closer muscles could not be associated to decreased AROM. The mean value of the difference between PROM-AROM (DPA) was 1.2 mm. Frequent clenching and/or grinding was correlated to increased DPA only in hypermobile adolescents (r = 0.49***). Those with DPA exceeding 5mm had all reciprocal clicking.

Adolescent↗
PubMed2006

Cervical spine joint hypermobility: a possible predisposing factor for new daily persistent headache.

The objective of this study was to suggest that joint hypermobility (specifically of the cervical spine) is a predisposing factor for the development of new daily persistent headache (NDPH). Twelve individuals (10 female, 2 male) with primary NDPH were evaluated by one of two physical therapists. Each patient was tested for active cervical range of motion and for the presence of excessive intersegmental vertebral motion in the cervical spine. All patients were screened utilizing the Beighton score, which determines degree of systemic hypermobility. Eleven of the 12 NDPH patients were found to have cervical spine joint hypermobility. Ten of the 12 NDPH patients had evidence of widespread joint hypermobility with the Beighton score. Based on our findings we suggest that joint hypermobility, specifically of the cervical spine, may be a predisposing factor for the development of NDPH.

Adolescent↗
PubMed2003

In-vivo measurement of dynamic joint motion using high speed biplane radiography and CT: application to canine ACL deficiency.

Dynamic assessment of three-dimensional (3D) skeletal kinematics is essential for understanding normal joint function as well as the effects of injury or disease. This paper presents a novel technique for measuring in-vivo skeletal kinematics that combines data collected from high-speed biplane radiography and static computed tomography (CT). The goals of the present study were to demonstrate that highly precise measurements can be obtained during dynamic movement studies employing high frame-rate biplane video-radiography, to develop a method for expressing joint kinematics in an anatomically relevant coordinate system and to demonstrate the application of this technique by calculating canine tibio-femoral kinematics during dynamic motion. The method consists of four components: the generation and acquisition of high frame rate biplane radiographs, identification and 3D tracking of implanted bone markers, CT-based coordinate system determination, and kinematic analysis routines for determining joint motion in anatomically based coordinates. Results from dynamic tracking of markers inserted in a phantom object showed the system bias was insignificant (-0.02 mm). The average precision in tracking implanted markers in-vivo was 0.064 mm for the distance between markers and 0.31 degree for the angles between markers. Across-trial standard deviations for tibio-femoral translations were similar for all three motion directions, averaging 0.14 mm (range 0.08 to 0.20 mm). Variability in tibio-femoral rotations was more dependent on rotation axis, with across-trial standard deviations averaging 1.71 degrees for flexion/extension, 0.90 degree for internal/external rotation, and 0.40 degree for varus/valgus rotation. Advantages of this technique over traditional motion analysis methods include the elimination of skin motion artifacts, improved tracking precision and the ability to present results in a consistent anatomical reference frame.

Animals↗
PubMed2003

Thermomechanical analysis of soft-tissue thermotherapy.

Soft-tissue thermotherapy based on sub-ablative heating of collagenous tissues finds wide-spread application in medicine such as tissue welding, thermokeratoplasty, skin resurfacing, elimination of discogenic pain in the spine and treatment of joint instability. In this paper, heat-induced thermomechanical response characteristics of collagenous tissues are quantified by means of in vitro experimentation with a representative model tissue (New Zealand white rabbit patellar tendon). Three distinct heat-induced thermomechanical response regimes (defined by the rate of deformation and the variation of material properties) are identified. Arrhenius damage integral representation of collagenous tissue thermal history is shown to be adequate in establishing the master response curves for quantification of thermomechanical response for modeling purposes. The trade-off between the improved kinematical stability and compromised mechanical stability of the heated collagenous tissue is shown to be the major challenge hindering the success of subablative thermotherapies.

Adaptation, Physiological↗
PubMed1983

Normal joint mobility in mitral valve prolapse.

Thirty-seven adults (19 male, 18 female) with mitral valve prolapse (MVP) were examined for evidence of joint hypermobility scored on a 0-9 scale. None of the patients had hypermobility scores exceeding 3, and comparison with 37 healthy age and sex matched controls recruited from hospital staff failed to show an increased prevalence of hypermobility in MVP. There was no evidence that the MVP syndrome is a forme fruste of a heritable disorder of connective tissue.

Adolescent↗
PubMed1984

Quantitative measurements of joint mobility in adolescents.

Six measurements of joint mobility were made in a group of 446 normal adolescents. A method of measuring hip and knee rotation is presented. All these data are normally distributed, and would suggest that joint hypermobility lies at the end of the normal spectrum. There was a weak but significant correlation between each of the different measures of joint mobility except elbow hyperextention. Criteria for joint laxity are discussed in this age group, and the importance of quantitative techniques of measuring joint mobility are emphasised.

Adolescent↗
PubMed2006

Tennis specific limitations in players with an ACL deficient knee.

BACKGROUND: Complete rupture of the anterior cruciate ligament (ACL) causes significant alteration of knee joint kinematics. Untreated patients often develop joint instability, chronic articular degeneration, and knee dysfunction. Demands on the ACL produced by playing tennis have not been investigated. OBJECTIVE: To identify subjective sport-specific limitations in tennis players with isolated unilateral ACL deficiency. STUDY DESIGN: Prospective case-control study. METHODS: 16 players (mean (SD) age, 39.9 (2.3) years; 14 men) with a chronic unilateral ACL deficient knee and 16 healthy controls (38.25 (8.47) years; 14 men) were recruited. ACL deficiency was confirmed by clinical and magnetic resonance imaging. A Lysholm score was obtained in all patients, together with subjective evaluation of their current tennis performance compared with pre-injury levels, applying a 0-100% visual scale. Both groups completed a questionnaire on tennis specific abilities. RESULTS: Lysholm scores were: 85.6 (10.3) points in the study group and 100 (0) points in the control group (p<0.001, t test for independent samples). Injured players evaluated their current tennis performance as 66.8 (15.2)% compared with 100% pre-injury level (p<0.005, t test for dependent samples). Abilities affected in the ACL deficient group were landing after a smash stroke (p<0.001); stopping abruptly and changing (p<0.001); playing a three set singles match (p<0.05); and playing on a hard court surface (p<0.001, Kolmogorov-Smirnov test). CONCLUSIONS: There are specific limitations associated with complete isolated ACL rupture, including subjective tennis performance impairment, limitations landing after a smash, stopping and changing step direction, difficulties playing a three set singles match, and playing on hard court surfaces.

Adult↗
PubMed1987

The clinical features of Ehlers-Danlos syndrome type VII due to a deletion of 24 amino acids from the pro alpha 1(I) chain of type I procollagen.

The clinical features and progress of a child with the type VII form of Ehlers-Danlos syndrome due to a deletion in the pro alpha 1(I) of type I procollagen were studied. The child was born with bilateral dislocations of hips and knees and all other joints were markedly hypermobile. Persistent severe joint instability was the major clinical abnormality. She had a depressed nasal bridge with prominent paranasal folds and deeply set eyes with mild hypertelorism and micrognathia. The skin was soft, moderately hyperelastic, and sagged over the face and knees. Skin fragility and easy bruising appeared when she started walking. Electron microscopy of the dermis showed irregular collagen fibrils.

Amino Acid Sequence↗
PubMed1978

Morphology, histology and functional anatomy of the canine cranial cruciate ligament.

Morphologically the canine cranial cruciate ligament can be divided into a cranio-medial and caudo-lateral component which perform reciprocal functions at all angles of flexion of the stifle joint. Histologically the main constituents of these two components are bundles of longitudinally orientated collagen fibre. The results of the study of the effect of partial and total sectioning of the cranial cruciate ligament on the "anterior-draw" movement implied that the relatively minor degree of movement, elicited following sectioning of either of the components of the ligament, would not be detected under clinical conditions. For joint instability to be clinically detectable most of the ligament must have ruptured, or the intact portion must have undergone degenerative or disruptive changes.

Animals↗