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At least 19 recordsLinked to original sources
PubMed1978

Fusion for instability and potential instability of the cervical spine in children and adolescents.

Instability and potential instability of the cervical spine in the child and adolescent not presenting as emergencies may be due to many causes. We have reviewed 30 patients treated surgically over a seven year period and have grouped them under four general headings: isolated congenital anomalies of the cervical spine, postlaminectomy instability, traumatic instability with delayed presentation, and bony or ligamentous inadequacy secondary to miscellaneous conditions. The variety of conditions permits few generalizations. However, an overview of the entire group supports the concept that abnormal motion in an immature spine or the potential for such motion should be viewed cautiously by the orthopedist, for it may herald severe neurologic compromise. When compromise has occurred, the decision to intervene is made easier. Should only increased motion or the potential for such be present, the natural history of the lesion, if available, should be the guide to treatment. If the natural history of a cervical spine lesion is not available and structural integrity is compromised with abnormal motion present, fusion is advised. Appropriate patient counseling as to the lack of an alternative, with the exception of prolonged bracing to avoid the hazards of life, is essential in this group of individuals.

Adolescent↗
PubMed1990

[Bladder instability and kinesitherapy. The concept of deficient bladder instability].

The authors present a series of 30 unstable bladders treated only by perineal muscular reeducation by contact. The best results are obtained in the group presenting with pelvic floor hypotonia and USI (urinary stress incontinence) (efficiency 71.5%), especially when the closure pressure is normal (100%). The urodynamic control and the ominous disappearance of the associated USI confirm a muscular role of the treatment rather than a psychogenic one, the stabilization of the bladder being achieved through the perineo-detrusor inhibitory reflex. Because of this specific and efficient treatment the attention is drawn to the pelvic muscular weakness in the genesis of detrusor instability which is then called "deficitory instability". The interest of a clinical classification of detrusor instability is discussed.

Adult↗
PubMed1988

Detrusor instability and bladder outflow obstruction. Evidence for a correlation between the severity of obstruction and the presence of instability.

Forty patients with bladder outflow obstruction due to benign prostatic hypertrophy were assessed by means of symptom analysis, rectal examination, intravenous urography and/or cystoscopy, medium-fill water cystometry and pressure flow study. No significant correlation was found between the severity of obstruction and the degree of instability, but the occurrence of instability did correlate with the degree of obstruction. This latter conclusion, though logical, had not been proved before, and was achieved by means of a new urodynamic parameter.

Aged↗
PubMed1987

CT-functional diagnostics of the rotatory instability of the upper cervical spine. Part 2. An evaluation on healthy adults and patients with suspected instability.

Nine healthy adults and 43 patients with cervical spine injury were examined by using functional (computerized tomography) CT scanning. The ranges of axial rotation at the levels occiput C0-C1, C1-C2, and C2-C3 were measured. A rotation at C0-C1 greater than 8 degrees; at C1-C2, 56 degrees; or a right-left difference C0-C1 greater than 5 degrees and C1-2 greater than 8 degrees indicates hypermobility. A rotation at segment C1-C2 of less than 28 degrees indicates hypomobility. Surgical stabilization of rotatory instability could be considered as a possible therapeutic procedure.

Adolescent↗
PubMed1992

[Multi-directional instability of the shoulder; e new form of chronic shoulder instability].

This article describes multidirectional shoulder instability. This lesion is not rare and is easily overlooked. MDI is often caused by repeated minor injuries in athletic patients. The basic lesion in MDI is an enlarged joint volume. The diagnosis is based on the clinical picture. The sulcus sign is pathognomonic. Conservative treatment is the treatment of first choice. If complaints persist after one year of conservative treatment, a capsular shift as described by Neer is recommended.

Adolescent↗
PubMedDate not supplied

[Factors determining the instability of the conformation of human mutant hemoglobins. A method for evaluating the instability].

A method that allows to estimate the influence of single amino acid substitutions on the stability of proteins with known three-dimensional structure was developed. The role of 20 different physico-chemical properties of amino acids and some characteristics of the three-dimensional structure in the destabilization of protein structure caused by mutations was analyzed. Analysis of 54 proteins led us to reveal the characteristics of the three-dimensional structure. The parameters of the method were calculated on the basis of experimental data for 330 mutant human hemoglobins. The prediction accuracy of the method is on average 81%. The method may be used for the analysis of the total mutational spectra of the proteins and also for the estimation of effects of the single amino acid substitution on the protein structure in gene-engineering experiments.

Amino Acid Sequence↗
PubMed1991

An anatomic basis for spinal instability: a porcine trauma model.

To determine the anatomic basis for spinal instabilities, 16 porcine cervical spine specimens were subjected to a well-defined sagittal plane trauma. The multidirectional instability of each specimen was measured before and after trauma. Detailed anatomic dissections were performed on each traumatized specimen to quantitate the extent of injury to several distinct anatomic structures and columns. Multiple regression models were constructed to determine which anatomic structures and columns correlated best with each multidirectional instability. Flexion instability correlated best with injury to the interspinous/supraspinous ligaments and the ligamentum flavum. Extension instability correlated best with anterior longitudinal ligament and pedicle injury. Axial rotation instability correlated best with anterior disc-end-plate and capsular ligament injuries, while lateral bending instability correlated best with posterior disc-end-plate injuries. Anterior column injuries correlated best with extension, axial rotation, and lateral bending instabilities, while posterior column injuries correlated best with flexion instability. Finally, individual anatomic structural injuries had higher correlations with multidirectional instabilities than did the injuries defined by the anatomic columns.

Animals↗
PubMed1988

Postdecompression lumbar instability.

In the last two decades, the concept of spinal stenosis and its treatment by surgical decompression has been widely accepted. Complications such as olisthy, disc rupture, facet fracture, and intractable back pain began to appear postoperatively, suggesting instability as their cause. A retrospective study of 344 patients treated surgically for lumbar stenosis revealed a 17% reoperation rate for complications resulting from obvious or suspected instability. Sixteen cases of postdecompression olisthy, 14 cases of fresh disc herniation, and 27 cases of intractable back pain required further surgery. Preoperative indicators of potential instability are degenerated discs as evidenced by traction spurs or diminished disc height, olisthy, and scoliosis or asymmetrically narrowed discs. Total facetectomy and pars excision at surgery destabilize the spine and must be added to the preoperative risk factors for instability. Calcified annulus, capsule and ligamentum flavum, or complete disc resorption may offer some protection from postoperative instability. The level of instability may be preselected by the proximity to the intercrestal line. It is recommended that during surgical decompression for spinal stenosis, the posterior elements be spared as much as possible to avoid instability after surgery. Factors suggesting instability noted preoperatively or decompression which produces instability suggest that fusion should be combined with decompression. Spinal fusion is the treatment for postoperative instability.

Adult↗
PubMed1989

Glenohumeral instability.

Glenohumeral instability is an important cause of shoulder pain and disability in an active population. An awareness of the prevalence of recurrent instability, either in the form of dislocation or subluxation, is particularly useful in the assessment of the young athlete presenting with shoulder pain. Young adults presenting with rotator cuff tendinitis may have an underlying instability as the primary cause of their problem. A careful clinical examination should determine whether the instability is voluntary or involuntary, of traumatic or atraumatic onset, and the primary direction of the instability, as these factors have important implications with regard to treatment. Anterior glenohumeral instability is most common and the incidence of recurrent instability following on from an initial dislocation is high in the young active patient. An intensive rehabilitation programme is indicated for all initial dislocations or subluxations but surgery may become necessary after failure of conservative treatment. Care must be taken to determine accurately those patients with voluntary or multi-directional instability and a longer trial of conservative treatment is indicated here, as results of operative treatment in those cases are less favourable. Conservative treatment should be directed at strengthening the dynamic stabilizers of the shoulder joint, notably the rotator cuff muscles. Additional X-ray views are needed to demonstrate all the radiological changes associated with recurrent instability and further evaluation with examination under anaesthesia and arthroscopy is beneficial in the assessment of these patients. Arthroscopic surgery also has a role in the treatment of patients with symptomatic labral pathology and is now being used to perform stabilization procedures in selected cases. Many operative procedures have been described for stabilization of the shoulder and these should be directed at correcting the pathology present. Restoration of the patient's flexibility and strength postoperatively is essential, especially in the athlete in order to allow a full return to sporting activity.

Combined Modality Therapy↗
PubMed1986

Clinical significance of urethral instability.

Variations of urethral pressure were registered with microtransducers in 427 gynecologic patients with lower urinary tract symptoms during urethrocystometry. Urethral instability (variation of urethral pressure greater than 15 cm of water) was found in 16.4% of patients. The comparison of the urinary symptoms and the urodynamic data between patients with urethral instability (without previous surgery for incontinence, N = 57), and patients with stable urethra (variation of urethral pressure less than 5 cm of water, N = 269) showed that urethral instability was related to frequency, nycturia, urgency, and a history of urethral syndrome. In 27% of patients, the urethral instability was associated with a bladder instability. The comparison between patients with urethral instability and stable bladder (N = 51) and patients with bladder instability and stable urethra (N = 41) revealed that bladder instability seems to be more important than urethral instability as a factor associated with nycturia, urgency, and urge incontinence.

Adult↗
PubMed1990

Analysis of sagittal plane instability of the lumbar spine in vivo.

Segmental instability secondary to degenerative disc disease may result in chronic low-back pain. In the sagittal plane, segmental instability can be characterized during lumbar motion from full extension to full flexion. The authors studied this movement using a translational method for the kinematic analysis, implementing a new concept known as the instability factor. Both translational and angular components of motion are evaluated. By computing the incremental motion parameters at different stages of spinal bending, the total amount of translation and angulation is obtained and combined in a ratio termed the instability factor. This factor increases with linear instability and decreases with rotational instability. The authors reviewed 12 control subjects and 36 patients with chronic low-back pain. The diagnoses of patients were categorized into three groups: idiopathic low-back pain, lumbar disc prolapse, and degenerative disc disease. Lateral radiographs of each subject's spine at the L4-5 level were obtained using low dose radiography and were performed serially as the subjects moved from full extension to full flexion. It was found that the group of patients with degenerative disc disease had an average age-corrected instability factor of 37.3 (mm/radian), which was significantly larger than that of normal subjects 25.5 (mm/radian), (P = 0.0065). No significant difference was seen in the instability factor of patients with idiopathic low-back pain or lumbar disc prolapse.

Adult↗