Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “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 1,135 records · Page 63Linked to original sources
PubMed1982

[Post-traumatic instability between the atlas and the axis in children. Apropos of 5 cases].

The authors have observed 5 cases of atlanto-axial instability in children aged from 18 months to 8 years. All the cases were seen after severe trauma and presented with abnormal neurological signs. All patients were first treated conservatively and were operated on secondarily by atlanto-axial fusion using graft and wiring for persistent radiological instability between the atlas and axis. In two cases instability was due to an atlanto-axial subluxation with rupture of the transverse ligament; one of these was reduced by traction. In one case there was an anterior subluxation without fracture. In one case there was a fracture of the odontoid process in which instability persisted in spite of bony union of the fracture. In the last case, the odontoid process was intact shortly after the trauma but its central portion disappeared secondarily. The cause of this disappearance is discussed.

Atlanto-Axial Joint↗
PubMed1984

Recurrent posterior instability (subluxation) of the shoulder.

A retrospective survey of fifty shoulders in thirty-five patients with recurrent posterior instability revealed generally poor results of treatment, particularly of operative treatment. Only eleven of the shoulders had a primary traumatic insult as the event initiating the instability. Although forty-one of the affected shoulders demonstrated voluntary instability, it was the associated involuntary, unintentional instability of these shoulders that prompted the patients to seek medical attention. Pain and functional impairment relating to work and to the activities of daily living were not significant in most of these patients. The results of surgical reconstruction were generally poor, the recurrence rate was 50 per cent (thirteen of twenty-six shoulders), and there were complications in five of the twenty-six shoulders that had been operated on. Attention is drawn to the complication of degenerative osteoarthritis that is associated with posterior glenoid osteotomy. We advise care in the selection of patients for surgical reconstruction.

Activities of Daily Living↗
PubMed1984

The surgical treatment of instability of the upper part of the cervical spine in children and adolescents.

In a retrospective review of the cases of thirteen skeletally immature children and adolescents (four to eighteen years old) with instability of the upper part of the cervical spine (occiput to fifth cervical vertebra), we determined the efficacy of posterior arthrodesis and halo-cast immobilization in the management of this condition. The patients were divided into two groups: those with congenital vertebral anomalies alone (fusion or structural defects, or both) and those with cervical anomalies and systemic disorders (dwarfism, juvenile rheumatoid arthritis, Down syndrome, and cerebral palsy). Two patterns of instability were found: instabilities at intervertebral joints adjacent to vertebral fusions, and instabilities located in vertebral defects. For all patients treatment included a posterior arthrodesis with external immobilization by a halo cast, and in two patients internal fixation with wire was also used. Solid arthrodesis was obtained in the twelve patients who were treated with autogenous grafts (iliac cancellous bone in eleven and rib bone in one), and a non-union developed in a child who was treated with bank-bone rib segments. Posterior cervical arthrodesis with wire fixation carries some risk of neural injury and often is not applicable in children with anomalous vertebrae. Spine fusion using delicate exposure, decortication using an air-drill, and placement of autogenous cancellous iliac grafts with external immobilization by a halo cast minimizes the risk of neural damage and is a reliable way to obtain a solid arthrodesis.

Adolescent↗
PubMed1983

Treatment of knee joint instability secondary to rupture of the posterior cruciate ligament. Report of a new procedure.

For the past five years we have attempted to correct knee instability due to rupture of the posterior cruciate ligament with a procedure that employs a free graft of one-third of the patellar tendon with its tibial and patellar attachments. This procedure was done for chronic instability in thirty-three patients and was combined with primary repair of an acute mid-substance tear of the posterior cruciate ligament in fifteen patients. Moderate to severe articular injury of the medial femoral condyle was found at operation in 48 per cent of the patients with chronic injury. Seventy-one per cent of the patients for whom the interval between injury and ligament reconstruction was two to four years, and 90 per cent of those for whom the interval was more than four years, showed articular injury of the medial femoral condyle. Only 31 per cent of the patients, however, had preoperative radiographic findings that indicated femoral articular damage. Twenty-three of the twenty-five patients with a minimum follow-up of two years returned for evaluation. All of the ten patients who had had a repair and reconstruction of an acute ligament injury (whose average follow-up was forty-one months) had a static and functional result that was graded as good or excellent. Of the thirteen patients for whom surgery was done for chronic instability (whose average follow-up was thirty-one months), the over-all static and functional result was graded as good or excellent in eleven. These results indicate that the use of one-third of the patellar tendon for reconstruction in patients with acute mid-substance tears as well as in patients with symptomatic chronic instability of the posterior cruciate ligament is an effective procedure for achieving static and functional stability of the knee.

Adult↗
PubMed1993

[The X-ray diagnosis of degenerative cervical spinal instability].

Fifty patients with signs of cervical instability (Group A) and 50 persons without them (group B) were studied. Lateral roentgenograms of the cervical vertebrae of each case were taken in flexion, neutral and extension positions. The cervical lordosis, range of motion of the cervical spine (flexion-extension), angular displacement (AD) and horizontal displacement (HD) were also measured. The results show that cervical lordosis of group A was more straight than group B and the reverse curves and S-shaped curves were observed on the films of Group A. The range of motion of the cervical spinae in group A was less than that in group B (P < 0.05), while AD and HD in the former group were both remarkably larger than those in the latter. AD was seen mostly at C3, and C4,5, and HD was mostly at C3,4,5 and rarely at C6. These results indicate, that there was corresponding changes on X-ray films in patients with symptoms of cervical spinal instability and the symptoms selected could be used as the symptoms of degenerative instability. The methods and criteria for diagnosis of cervical spinal instability and its treatment were discussed in the paper.

Adult↗
PubMed1994

Knee instability after total knee arthroplasty.

From 1986 to the present, 126 total knee revisions were performed by the authors. Twenty-five cases (20%) were revised for instability of the tibiofemoral articulation. Patellofemoral instability and those patients treated conservatively were excluded from this subset of patients. All patients were clinically evaluated using the Hospital for Special Surgery knee rating system and radiographically rated using The Knee Society scoring system. The average follow-up period was 28 months. Preoperative synovial fluid analysis showed a predominance of red blood cells (average, 64,000). Reasons for instability were ligamentous imbalance and incompetence, malalignment and late ligamentous incompetence, a deficient extensor mechanism, inadequate prosthetic design, and surgical error. All patients currently have stable knees with an overall improvement in clinical and radiographic scores. When evaluating a patient with a painful knee after total knee arthroplasty, this diagnosis should be considered. Careful physical examination, dynamic radiographs, and synovial fluid analysis should help to make a proper diagnosis. Treatment should aim to correct the cause of instability. The prosthesis chosen should compensate for the specific ligamentous deficiency present.

Follow-Up Studies↗
PubMed1994

[Results of surgical treatment of posterior knee instability].

A retrospective study was performed to evaluate the outcome of operative treatment of posterior cruciate ligament (PCL) lesions in 115 patients operated on between 1980 and 1989. Follow-up was possible in 89 patients at 18-124 months postoperatively (average 76 months). In 65 re-examination was possible, while 24 patients returned a questionnaire. The results of patients who were operated on in the acute state were superior to those with chronic instabilities (Lysholm 79.9 +/- 18.5 vs 64.3 +/- 22.1; Tegner 5.7 +/- 2.3 vs 4.2 +/- 2.2; instrumented posterior drawer 5.3 +/- 3.5 mm vs 5.9 +/- 3.8 mm). On the other hand, the preoperative scores of symptomatic patients with chronic instabilities (Lysholm 38.8 +/- 22.0; Tegner 2.1 +/- 1.7) were clearly lower. Extraarticular procedures (Hughston) slightly improved symptoms in posterolateral instabilities. Olecranization of the patella had no influence on the results. Interpretation of the data is difficult as there was no matched group of patients with nonoperative treatment. A reviews of the literature suggests that isolated PCL tears are best treated with conservative management. Only in cases where associated ligamentous injuries require operative treatment should PCL reconstruction be performed. Chronic posterior instabilities should be treated operatively only if the patients are severely symptomatic. However, complete restoration of knee stability was usually not achieved with the techniques presented in this paper.

Adolescent↗
PubMed1993

Chronic ankle instability as a cause of peroneal tendon injury.

Chronic lateral ankle pain and instability can be associated with a split in the peroneus brevis tendon. This case reports a peroneus brevis split that was centered over the sharp posterior edge of the fibula and was associated with laxity of the superior peroneal retinaculum, and chronic ankle instability. The mechanism of the split was easily demonstrated during surgery by everting the foot and pulling longitudinally on the peroneus longus tendon. The interrelationship of lateral ankle instability with superior retinacular laxity and resultant peroneus brevis splits can account for posttraumatic lateral ankle pain. Surgical treatment must identify and correct the underlying pathology and should attempt to repair or debride the peroneus brevis tendon, reconstruct the superior peroneal retinaculum, flatten the posterior edge of the fibula by removing the sharp bony prominence, and address any associated lateral ankle instability with either a modified Chrisman-Snook, Anderson, or modified Brostrom-Gould procedure.

Adult↗
PubMed1993

[Shoulder instability and pain. Computerized arthro-tomography assessment].

The growing interest in shoulder joint imaging comes from the ever-increasing demand for such an examination in orthopedics. Since more complete and detailed imaging of bone, capsuloligamentous and musculotendinous compartments is always needed, CT arthrography has necessarily become a widely used method. In this study, 282 patients were investigated with CT arthrography. Seventy per cent of them had anatomical instability, 17.3% had functional instability and the extant 12.7% had shoulder pain. In traumatic instability, the most often injured structures were the glenoid labra (91%) and the capsule (82%). Lesions in the two structures were nearly always associated. Moreover, high incidence (65.8%) of Hill-Sachs lesions of the humeral head was observed. In atraumatic instability, abnormal anteversion of the scapular glenoid was always detected. In the patients with shoulder pain, the most common causes were the impingement syndrome (30.5%), superior labrum lesions (16.7%), adhesive capsulitis (16.7%) and synovial osteochondromatosis (13.7%). With CT arthrography, labial abnormalities (detachments, tears, amputations, eversions and degeneration) can be identified, as well as capsular lesions (insertional detachment and laxity), rotator cuff conditions (bursitis, tendinitis and partial/complete tears), biceps tendon abnormalities and glenoid rim and humeral head fractures. Moreover, CT arthrography is minimally invasive and well tolerated. It exhibits 97.7% specificity, 91% sensitivity and 96% accuracy. Furthermore, it has been proven to be extremely useful in treatment and surgical planning.

Adolescent↗
PubMed1993

[Carpal instability].

Traumatic carpal instability implies that the normal relationships of the radiocarpal and mid carpal joint are distorted either statically or during dynamic stress. Normal kinematics of the carpus are dysfunctional. The causes of carpal instability are dissociation of the intercarpal ligaments on either side of the lunate, a so-called scapholunate dissociation or a luno-triquetral dissociation. Carpal instability nondissociative is generally due to a laxity or attenuation of the intrinsic ligaments of the carpus and are associated with deformity of the distal radius. Ulnar translation of the carpus on the distal radioulnar articular surfaces occurs with shear stretching of the origins of the radiocarpal ligaments. The radial styloid attenuation of the ligaments may result in abnormal motions of the carpal bones going from ulnar to radial deviation at which time a catch-up click may occur. Carpal instabilities are usually associated with malalignment of the lunate with respect to the longitudinal axes of the radius and capitate and tends to assume an extended position with scaphoid fractures or injuries to the scapholunate ligament, a palmar flexed position with injuries to the luno-triquetral area or the ulnar capsule.

Biomechanical Phenomena↗
PubMed1993

The diagnosis and treatment of anterior instability in the throwing athlete.

In the overhand or throwing athlete, the shoulder is extremely vulnerable to injury due to the repetitive, high-energy forces. When these stresses are applied at a rate that exceeds that of tissue repair, progressive damage to the shoulder's stabilizing structures can occur. With continued throwing, the static restraints become progressively attenuated, allowing anterior glenohumeral subluxation. Initially, the dynamic stabilizers can compensate for this mild instability with increased muscle activity. Prolonged activity, however, may lead to fatigue. Over time, these compensatory mechanisms can become overloaded. The humeral head then may subluxate anteriorly, where it contacts with the coracoacromial arch, ultimately leading to subacromial impingement. Posterosuperior glenoid impingement may also occur as anterior humeral translation allows the undersurface of the tendinous portions of the supraspinatus and infraspinatus to impinge along the posterosuperior border of the glenoid rim. Fortunately, conservative management is effective in most chronic overuse injuries and includes an initial period of relative rest (avoidance of throwing), oral nonsteroidal antiinflammatory medication, a physical therapy program structured to provide local modalities to reduce inflammation, and a strengthening program for the rotator cuff and scapular rotators. For those athletes with continued symptoms, surgical intervention may become necessary. The appropriate surgical treatment depends on the diagnosis. In the young throwing athlete with shoulder pain, it is essential to recognize that instability or occult subluxation, rather than impingement, is the primary underlying pathology. The anterior capsulolabral reconstruction addresses the problem of instability by correcting the capsular redundancy or labral damage or both. When performed in the manner described, muscle attachments and proprioceptive muscle fibers are not disturbed and full shoulder range of motion can quickly be achieved. This most recent surgical technique and postoperative rehabilitation program has resulted in a significant improvement in the ability to correct instability in those athletes who have failed a prolonged course of conservative care. Prevention of these injuries may be attained, it is hoped, through continued research into the basic biomechanics and the pathoanatomy associated with overhand sports.(ABSTRACT TRUNCATED AT 400 WORDS)

Arthroscopy↗
PubMed1995

[Quadriceps dysplasia and patellar tilt in objective patellar instability].

PURPOSE OF THE STUDY: Dysplasia of the vastus medialis, a well-known landmark of patellar instability, is difficult to point out pre-operatively. We propose the measurement of patellar tilt on the CT scans in order to appreciate abnormality. MATERIAL AND METHODS: We studied 3 well defined groups: 143 knees operated on for a true dislocation of the patella, either for the first time or a recurrent episode, 67 asymptomatic and nonoperated contralateral knees and 54 control knees. The patellar tilt in extension was measured on the CT-scan with the quadriceps relaxed and contracted. RESULTS: The results showed the increase of the patellar tilt as an characteristic factor of patellar instability (28.8 + 10.5 degrees against 11.8 degrees + 5.7 degrees in the control group). Patellar tilt was not a consequence of the dislocation because it was also significantly increased in the asymptomatic contralateral group (17 degrees + 9 degrees). Quadricipital contraction increased the patellar tilt only in the two groups of patellar instability (+ 6 degrees) and asymptomatic contralateral group (+ 13 degrees) but not in the control group (+ 1.6 degrees). The mean of the relaxed and the contracted quadriceps patellar tilt includes the dynamic trouble. We propose the threshold of 20 degrees to determine a pathological patellar tilt. In this case, sensibility is 90 per cent and the specificity is 91 per cent. In the other patellar instability factors, only severe trochlear dysplasias involved the patellar tilt. DISCUSSION: We think that the patellar tilt in extension is a landmark of a functional disorder of the whole quadriceps muscle more than the vastus medialis only. The mean of the relaxed and contracted quadriceps patellar tilt measures permitted to point out the border cases of this functional abnormality. This measurement is reliable and can be considered pathologic above 20 degrees. The results of Insall's muscular plasty were only symptomatic because this procedure could not correct the effect of the quadricipital contraction.

Adolescent↗
PubMed1996

[Diagnosis and therapy of shoulder instability].

Shoulder instability is based on various acquired or constitutional aspects which determine the therapy and clinical outcome. In order to differentiate between traumatic and atraumatic forms of shoulder instability a careful history has to be taken. A systematic clinical examination is necessary to evaluate the shoulder joint for general laxity or true instability and especially to assess direction and degree of glenohumeral translation. The basic diagnostic imaging includes X-rays in 3 planes. CT-arthrogram and MRI may provide additional information to evaluate the intraarticular pathology. An elective therapy depends on the patients age and demands. Recurrent anterior dislocations are treated by an anatomical reconstruction of the glenohumeral ligament complex. Open or arthroscopic Bankart-repair have been established as the treatment of choice. Conservative treatment is primarily indicated in cases of atraumatic posterior or multidirectional instability. If physiotherapy fails, surgical treatment should be discussed for these patients.

Diagnosis, Differential↗
PubMed1996

The effect of postlaminectomy spinal instability on the outcome of lumbar spinal stenosis patients.

Between 1986 and 1990, 37 of 72 patients undergoing decompressive lumbar laminectomy with medial facetectomy for lumbar stenosis at The Ohio State University were seen in follow-up at a mean of 31 months (range, 14-63 months) after their laminectomy and were evaluated by questionnaire, detailed neurologic examination, and static and dynamic lumbar radiographs. Thirteen patients who had undergone fusion or who had extenuating medical circumstances were excluded, leaving 24 patients for whom laminectomy was the sole treatment for lumbar stenosis. Postoperatively, normal walking improved from 4 to 45% of patients, sensory deficits decreased from 63 to 25%, and ability to perform most or all desired activities increased from 25 to 70%. Urinary function was unchanged. Thirteen patients (54%) showed radiographic signs of instability. All patients who were declared radiographically stable could walk without a prosthetic aid or normally; 62% of the unstable patients required aid for walking. All of the patients with a poor ambulatory outcome were radiographically unstable. Compared with stable patients, unstable patients had a significant (p < 0.01) decrease in their ambulatory ability. There was a clear correlation between the degree of listhesis and postoperative ambulatory status (p < 0.01). The unstable patients with a poor ambulatory outcome followed one of three clinical courses: improvement with later deterioration, improvement with a plateau at a poor functional level, or failure to improve from a poor functional level. In conclusion, (a) although instability did not necessarily preclude a good outcome, a poor ambulatory outcome was always associated with instability; (b) laminectomy can effectively ameliorate the symptoms of lumbar stenosis; however, there is a subset of patients in whom laminectomy is associated with instability and a poor clinical course.

Adult↗
PubMed1996

[Arthroscopic treatment of chronic anterior instability of the shoulder by staple capsulorrhaphy. Apropos of a series of 55 patients with a minimum of 18 months follow-up].

PURPOSE OF THE STUDY: The authors studied the results of the arthroscopic staple capsulorrhaphy of 55 patients who had recurrent anterior shoulder instability. MATERIALS AND METHODS: There were 38 men and 17 women. The average age at operation was 30.3 years (17 to 68) and the dominant side was injured in 33 patients. 28 (51 per cent) patients had recurrent dislocations, 19 (38 per cent) patients had recurrent subluxations and 8 (14 per cent) complained of a painful shoulder with instability. Multidirectionnal hyperlaxity and glenoid rim fracture cases were excluded from this study. The average duration of symptoms was 43 months (i to 180). At operation, 46 patients had a Bankart lesion (Adolfsson A or C) and 9 had "non Bankart" lesion (Adolfsson B and intra ligamentous disruption). There were 6 (11 per cent) SLAP II lesions and 23 (42 per cent) other glenoid labral tears associated with main instability lesions. 58 staples were inserted. 53 inferior glenoid humeral ligament were fixed to the glenoid rim and in 2 cases we performed a subscapularis tendon tenodesis. RESULTS: The follow-up was continued for at least 18 months after treatment by an examiner different from the operating surgeon. (Average follow-up was 29.8 months). The results were assessed according to "Duplay" rating scale. Overall we have obtained 64 per cent excellent and good results. 71 per cent of shoulders were considered stable at revision whereas 7 per cent showed recurrent dislocation. 60 per cent of patients were able to return to their previous sport level. A limited range of motion was noted in only 11 per cent of cases. On the other hand 54 per cent of patients presented persistent pain. With regard to the shoulder stability, the factors possibly having a negative influence were the occurrence of an initial acute dislocation, the destruction of the inferior glenohumeral ligament (disruption or absence) and the sub-equatorial position of the staple on the anterior glenoid rim. Pain was more frequent in cases where there was associated subacromial impingement and where the staples had been badly positioned. DISCUSSION: We have compared our results with those of other authors who also performed stapling procedures, including different arthroscopic techniques and results of open stabilization surgery. Our results regarding shoulder instability were better than those obtained by arthroscopic sutures, equivalent to those obtained by the "Open Bankart" procedure, but less impressing than those obtained by the "Bone Block" procedure (Patte). However, pain was observed much more frequently than with all the other stabilization techniques, arthroscopic or not. CONCLUSION: Arthroscopic stapling therefore seemed to be less reliable than the "Patte Bone Block" procedure. At present, we reserve arthroscopic stabilization for patients with a good inferior glenohumeral ligament. Until an adapted biodegradable staple is perfected, we still use an anchorsuture technique to avoid pain due to metallic implant.

Adolescent↗
PubMed1998

Ulnar-sided wrist pain and instability.

A variety of lesions have been associated with ulnar-sided wrist pain and/or VISI instability. A staging system for ulnar-sided perilunate instability describes progressive disruptions associated with lunotriquetral dissociation that can lead to VISI instability and emphasizes the importance of the dorsal radiocarpal ligament in preventing VISI instability. Previous studies have emphasized association between type II carpal morphology and arthrosis at the proximal pole of the hamate, which was identified as the most common location of arthrosis in the wrist. The pisotriquetral joint is another common site of degenerative changes. A better understanding of the normal anatomy and kinematics of the ulnar side of the wrist will better enable physicians to identify and treat problems in the ulnar aspect of the wrist.

Arthralgia↗
PubMedDate not supplied

Serum relaxin in the newborn is not a marker of neonatal hip instability.

It has been suggested that intrauterine exposure to high levels of relaxin causes hip instability in newborns. The aim of this work was to evaluate whether the serum relaxin concentration in umbilical vein blood is associated with hip instability in the newborn. Blood was collected by cordocentesis from 2,185 newborns, and serum relaxin levels were obtained by using a standard sandwich enzyme-linked immunosorbent assay (ELISA). Movement of the femoral head in the hip joint was determined for all 2,185 children by the anterior-dynamic ultrasound method. Hereby their status on neonatal hip instability was determined. Fifteen cases (12 girls, three boys) were found, and 106 controls were selected. Only six newborns had unstable hips to a degree requiring treatment. Ten newborns had Ortolani-positive hips. Only three specimens of the 121 samples measured had serum relaxin concentrations above the detection limit of 10 pg/ml. None of these were cases. This study does not show an association of serum relaxin with neonatal hip instability. It is suggested that detectable serum relaxin levels are found in samples from the umbilical cord only when these are contaminated with maternal blood.

Biomarkers↗
PubMed1998

Open surgical treatment of anterior glenohumeral instability: an historical perspective and review of the literature. Part I.

Anterior glenohumeral instability is an undesirable result of trauma to the shoulder. Several surgical treatments for this condition have been developed, beginning in the early years of the twentieth century. Although these procedures were usually popular at their inception, many of them have fallen out of favor as more information has been acquired concerning the long-term results and complications of their use. Often successful in preventing recurrent instability, these earlier procedures also often led to a loss of external rotation, and consequently, function. Newer procedures that aim to prevent recurrent instability while maintaining full range of motion and function have been devised. Part I of this paper presents a brief history of the treatment of glenohumeral instability and a review of the literature, including the Bankart and du Toit procedures. Part II, which will be published in the December 1998 issue, includes the Putti-Platt, Magnuson-Stack, Bristow, and newer procedures.

History, 20th Century↗