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PubMed2002

Open capsular shift for multi directional shoulder instability.

We evaluated the outcome of open antero-inferior capsular shift in 17 patients with multidirectional instability of the shoulder who failed to respond to conservative treatment. Six shoulders presented with secondary impingement syndrome and 11 with involuntary instability. The mean duration of follow-up was 39 months (range 7-89 months). Based on the Rowe and Constant scores and the 12-item questionnaire of Dawson, the results were rated excellent in 14 patients, fair in 2 and poor in 1. All but 2 patients were satisfied with the results, although 6 patients experienced some residual pain, and 4 suffered minor instability. There were no neurovascular complications, infections or symptomatic posterior instability. Open antero-inferior capsular shift yields promising short-term to medium-term results in multidirectional, involuntary instability of the shoulder.

Adult↗
PubMed2003

Predictors of early and late instability following conservative treatment of extra-articular distal radius fractures.

INTRODUCTION: The purpose of this study was to identify radiological predictors of early and late instability following conservative treatment of extra-articular distal radius fractures. MATERIALS AND METHODS: An observational study design was employed using patient records and standardized radiological follow-up examinations as data sources. The database at a single institution was used to identify all patients with extra-articular distal radius fractures over the course of 1 year. A total of 71 patients with extra-articular distal radius fractures (50 dorsally displaced, 21 undisplaced) fulfilled the inclusion criteria. Patients were predominantly female (87%) with a pooled mean age of 64.9 years. All patients with displaced extra-articular distal radius fractures underwent closed reduction with subsequent cast immobilization. Undisplaced fractures were simply treated with cast immobilization. The primary outcomes were early (1 week) and late (6 weeks) instability of the fracture. Instability was defined as: (1) dorsal tilt >15 degrees, (2) volar tilt >20 degrees, (3) ulnar variance >4 mm, (4) radial inclination <10 degrees. RESULTS: Degree of radial shortening and volar tilt were predictive of early instability ( p<0.05), with dorsal comminution also approaching statistical significance ( p=0.06). Radial inclination, age, radial shortening, and volar tilt were predictive of late failure ( p<0.05). An unexpected result showed that one-third of undisplaced fractures went on to fail, most of which occurred in those patients over the age of 65 years. CONCLUSION: An awareness of independent predictors of instability in extra-articular distal radius fractures is helpful in anticipating the final alignment outcome.

Age Distribution↗
PubMed2004

Pathophysiology and treatment of atraumatic instability of the shoulder.

The shoulder is stabilized mainly by negative intraarticular pressure when the arm is at the side of the body with all the muscles relaxed. During arm motion in the midrange of motion, the contraction force of the muscles provides dynamic stability. In shoulders with atraumatic instability, the joint capsule is thin and enlarged, making it more difficult to maintain the negative pressure. Decreased joint volume by capsular imbrication results in creating the negative intraarticular pressure. Imbalance of muscle forces may cause decreased abduction of the scapula during arm elevation or decreased concavity compression (or both), either of which may result in instability. Muscle exercises are effective in most cases of atraumatic instability. Congenital hypoplasia of the glenoid also contributes to decreased concavity compression. Glenoid osteotomy is the treatment of choice in such cases. One of these factors may play a role in the occurrence of atraumatic instability by itself or in combination. Better understanding of the pathophysiology of atraumatic shoulder instability is useful when selecting the best treatment option in each case.

Arm↗
PubMed2005

Trapeziometacarpal joint instability after Bennett's fracture-dislocation.

BACKGROUND: Investigation of trapeziometacarpal joint instability was undertaken following Bennett's fracture-dislocation. METHODS: We treated six patients who were experiencing trapeziometacarpal joint instability following Bennett's fracture-dislocation. The average age of the patients at the initial visit was 22.2 years. There were four men and two women. All six patients complained of trapeziometacarpal joint pain and instability preoperatively. Fluoroscopy confirmed that the beak fragment moved with the shaft fragment. The length of time from injury to surgery ranged from 1 to 29 months (average 10.7 months). Ligament reconstruction based on Eaton's method was performed on five patients, and in one patient the fracture site was osteotomized and reduced and the dorsoradial ligament repaired. RESULTS: Over an average follow-up observation period of 20 months, none of the patients complained of severe joint pain or instability. CONCLUSIONS: When treating Bennett's fracture-dislocation, it is necessary to pay careful attention not only to accurate anatomic reduction of the joint surface but also to joint instability.

Adolescent↗
PubMed1993

Carpal instability, the missed diagnosis in patients with clinically suspected scaphoid fracture.

To determine the incidence of carpal instability and its relation to clinical findings in patients with suspected scaphoid fracture, we performed a long-term follow-up investigation in a consecutive series of 160 patients who were treated in our department of traumatology for suspected scaphoid fracture after a fall on the outstretched hand. Radiography of the carpus was obtained. Bone scintigraphy was performed in all patients with negative initial radiographs. Follow-up investigation was performed in 100 patients and consisted of history, clinical examination, including measurement of grip strength and wrist movement, synovia stress test, Watson's scaphoid test, and radiographic examination. In 22 patients, clinical or radiological signs of carpal instability were found. The incidence of complaints and a positive synovia test were significantly higher in patients with suspected carpal instability. The bone scan was not useful for the detection or exclusion of carpal instability. The three-phase bone scan gave no additional information in the diagnosis of carpal instability.

Accidental Falls↗
PubMed1986

The role of carpal instability in scaphoid nonunion: casual or causal?

We studied twenty consecutive scaphoid nonunions in twenty patients between the ages of eighteen and thirty-eight years. There were nineteen males and one female. The mean age was 25.2 years. Factors evaluated were fracture displacement, delay in treatment, and carpal instability. Fracture displacement and carpal instability were documented in patients by abnormal x-rays showing fragment displacement, abnormal scapholunate and radiolunate angles, etc., or by fluoroscopically controlled arthrography. We concluded that intercarpal ligamentous instability is consistently present and, therefore, the critical factor in wrists with ununited scaphoid fractures. Thirteen patients have been treated surgically; ligamentous disruption was confirmed at surgical exploration. In twelve patients, treatment of the nonunion included intercarpal ligamentous reconstruction. A satisfactory outcome was achieved in all twelve of these patients. One patient's treatment did not include ligament reconstruction. Although the scaphoid fracture united after a Russe bone graft, he remains symptomatic with persistent intercarpal instability. The remaining seven patients are being evaluated or awaiting surgery. Since ligamentous injury is so common in nonunion, we believe it is causal and that surgical care of nonunion involves ligamentous repair or other stabilization procedure. Prevention of nonunion involves early attention to the therapy of carpal instability when associated with scaphoid fracture.

Adolescent↗
PubMed1990

Kinematics of the ulnar carpus related to the volar intercalated segment instability pattern.

Anatomic dissections were done on 18 fresh and 4 preserved cadaver upper extremities to study the pathology of the carpal kinetics and to define the ligaments involved in the volar intercalated segment instability pattern. In a normal wrist, the scaphoid, lunate, and triquetrum all rotate so that their distal surfaces tilt palmarward with radial deviation. With ulnar deviation, all three carpal bones rotate dorsally. In the volar intercalated segment instability pattern, the lunate remains tilted volarly instead of rotating dorsally with ulnar deviation. In this study changes in carpal motion were observed after serially sectioning the ligaments supporting the ulnar carpus before and after loads were applied to the wrist to simulate the dynamic conditions of the wrist. The ligaments were then repaired to help identify which repairs restored normal carpal motion with radial and ulnar deviation with and without axial loads. In these anatomic studies the volar intercalated segment instability pattern occurred when there was instability between both hamate and triquetrum and between the lunate and triquetrum. The main ligaments involved in this instability appeared to be the ulnar half of the volar arcuate ligament and the luno-triquetral ligament as division of these ligaments, particularly under axial loads, produced the most significant change in lunate rotation (p less than 0.05). Similarly repair of these two ligaments produced the most significant correction of lunate position particularly with maintenance of dorsal rotation of the lunate during ulnar deviation under axial loads (p less than 0.01).

Humans↗
PubMed1990

Effects of radioulnar instability on the radiocarpal joint: a biomechanical study.

Five fresh cadaver upper extremities were studied with use of a static positioning frame, pressure-sensitive film and a microcomputer-based videodigitizing system to assess the effect of increasing radioulnar instability on the load distribution within the proximal carpal joint. Three stages of radioulnar instability were studied: (1) an avulsion fracture at the base of the ulna styloid; (2) an avulsion fracture at the base of the ulna styloid plus disruption of the dorsal portion of the distal radioulnar joint capsule; and (3) an avulsion fracture at the base of the ulna styloid, disruption of the dorsal portion of the distal radioulnar joint capsule, and disruption of the radioulnar interosseous membrane. All stages of radioulnar instability demonstrated a decrease in the lunate contact area in positions with the forearm in supination. In stage 3 instability there was also less lunate contact area in positions with the forearm in neutral pronation/supination. In stage 3 instability the lunate high pressure area centroid was abnormally palmar in all positions and the scaphoid high pressure area centroid was abnormally palmar in positions with the forearm in pronation or supination.

Adult↗
PubMed1989

Arthroscopy and stability testing for anterior shoulder instability.

The extreme manifestation of anterior shoulder instability is anterior dislocation. Minor anterior instability often gives rise to vague symptoms from which a diagnosis is difficult. The use of arthroscopy may increase diagnostic accuracy in cases of anterior shoulder instability. Examinations were performed on 145 patients with shoulder complaints using stability testing under anesthesia and arthroscopy; of these, 62 patients were found to have anterior shoulder instability. The clinical signs were compared with the findings on stability testing and arthroscopy, and the morphological changes noted on arthroscopy were recorded. The combination of arthroscopy and stability testing proved valuable in the diagnosis of minor anterior instability and for the morphological changes and associated injuries in established anterior dislocations.

Adult↗
PubMed2006

The Cumberland ankle instability tool: a report of validity and reliability testing.

OBJECTIVE: To test the Cumberland Ankle Instability Tool (CAIT), a 9-item 30-point scale, for measuring severity of functional ankle instability. DESIGN: Cross-sectional study. SETTING: General community. PARTICIPANTS: Volunteer sample of 236 subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Concurrent validity by comparison with the Lower Extremity Functional Scale (LEFS) and a visual analog scale (VAS) of global perception of ankle instability by using the Spearman rho. Construct validity and internal reliability with Rasch analysis using goodness-of-fit statistics for items and subjects, separation of subjects, correlation of items to the total scale, and a Cronbach alpha equivalent. Discrimination score for functional ankle instability by maximizing the Youden index and tested for sensitivity and specificity. Test-retest reliability by intraclass correlation coefficient, model 2,1 (ICC(2,1)). RESULTS: There were significant correlations between the CAIT and LEFS (rho=.50, P<.01) and VAS (rho=.76, P<.01). Construct validity and internal reliability were acceptable (alpha=.83; point measure correlation for all items, >0.5; item reliability index, .99). The threshold CAIT score was 27.5 (Youden index, 68.1); sensitivity was 82.9% and specificity was 74.7%. Test-retest reliability was excellent (ICC(2,1)=.96). CONCLUSIONS: CAIT is a simple, valid, and reliable tool to measure severity of functional ankle instability.

Adult↗
PubMed2004

Kim's lesion: an incomplete and concealed avulsion of the posteroinferior labrum in posterior or multidirectional posteroinferior instability of the shoulder.

PURPOSE: The purpose of this article is to report a new clinical entity of posterior instability of the shoulder and the results of its treatment. TYPE OF STUDY: Case series. METHODS: The Kim's lesion, which is an incomplete and concealed avulsion of the posteroinferior labrum, was arthroscopically identified in 15 patients who presented with posterior or multidirectional posteroinferior instability. Patients were treated by arthroscopic labroplasty and capsular shift. At a minimum follow-up of 2 years, the outcome was evaluated using subjective (pain and function visual analogue scale) and objective (UCLA, ASES, and Rowe scores) measurements. RESULTS: When visualized under an arthroscope, Kim's lesion apparently had an intact labral attachment and appeared to have a superficial crack at the junction between the articular cartilage of the glenoid and the posteroinferior labrum. However, probing of the lesion revealed detachment of the deep portion of the posteroinferior labrum. The posteroinferior labrum was flat with loss of normal height, which resulted in the retroversion of the chondrolabral glenoid. Incision of the superficial portion of the lesion exposed a loose deep portion of the labrum. Labroplasty was performed to restore the labral height, as well as capsular shift with or without rotator interval closure. The surgical outcome was satisfactory in 14 patients and unsatisfactory in 1 patient. Shoulders were stable in all patients with unidirectional posterior instability. There was 1 recurrence of multidirectional posteroinferior instability. CONCLUSIONS: Kim's lesion is an incomplete avulsion of the posteroinferior labrum, which is concealed by apparently intact superficial portion. The clinical significance of this lesion is the need for surgeons to convert this concealed incomplete lesion to a complete tear and repair it with the posterior band of the inferior glenohumeral ligament. A failure to address this lesion may result in persistent posterior instability. LEVEL OF EVIDENCE: Level IV, therapeutic, Case Series.

Adolescent↗
PubMed2005

The use of arthroscopic thermal shrinkage to treat chronic lateral ankle instability in young athletes.

PURPOSE: The aim of this study was to evaluate the preliminary results of arthroscopic thermal capsular shrinkage performed for chronic lateral ankle instability in soccer players. TYPE OF STUDY: Case series. METHODS: We reviewed 22 male soccer players (average age, 18 years) with chronic lateral ankle instability who underwent arthroscopic thermal shrinkage between 1997 and 1998. The only exclusion criterion for this study was the failure of previous surgery. Before surgery, all patients had participated in a physical rehabilitation program consisting of peroneal strengthening exercises and proprioceptive training for several months, without any relief of their symptoms. All patients were characterized by repeated episodes of giving way, a positive anterior drawer sign, and positive stress radiographs. The stress radiographs consisted of a sagittal stress and talar tilt by the TELOS device (Fallston, MD). The Karlsson and Peterson ankle function scoring scale was used to assess these patients for their current activity level as well as activity before surgery. RESULTS: Patients were reviewed at a mean of 42 months (range, 32 to 56 months); 19 patients (86.3%) reported a good or excellent functional outcome as assessed by the Karlsson and Peterson ankle function scoring scale. Eighteen of the 22 patients presented no evidence of ankle instability on physical examination or on stress radiographs. Only 1 patient was not able to return to his previous level of sports activity and complained of ankle instability when walking on uneven ground. CONCLUSIONS: This study suggests that arthroscopic thermal capsular shrinkage is a valid and safe procedure for treatment of chronic lateral ankle instability. Longer follow-up is needed, however, to see how these results may change with time in high-demand athletes. LEVEL OF EVIDENCE: Level IV.

Adolescent↗
PubMed2005

Characterization of genomic instability in ulcerative colitis neoplasia leads to discovery of putative tumor suppressor regions.

Ulcerative colitis (UC) is an inflammatory disease of the colon that is associated with increased risk of colorectal cancer associated with genomic instability. We have previously demonstrated that genomic instability is present in UC patients with colonic neoplasia, and hypothesized that the chromosomal alterations may be taking place in regions that are susceptible to mutation or that provide a growth advantage to a cell undergoing neoplastic transformation. In this study, we used two polymerase chain reaction (PCR)-based DNA fingerprinting techniques (arbitrarily primed PCR and inter-simple-sequence-repeat PCR) to study the process of genomic instability. The two techniques of DNA fingerprinting cross-validate the instability observed in these studies. We analyzed the molecular basis of 10 commonly altered DNA bands obtained from DNA fingerprints of biopsies from various histologic grades of UC patients with dysplasia or cancer (UC Progressors). We determined that the band changes in the fingerprint truly represent changes in DNA sequence, and that the fingerprinting provides highly reproducible results. Furthermore, our investigation revealed that 40% of alterations involve repetitive sequences. Two frequently deleted sequences in 6q27 and 2q14 were studied further because they were frequently abnormal in the dysplastic and nondysplastic tissue of UC Progressors. The losses from 6q27 and 2q14 were confirmed by loss of heterozygosity and real-time PCR analysis. Both of these regions in chromosomes 6 and 2 are surrounded by highly repetitive and mobile LINE-1 elements, possibly making the region susceptible to mutational change. These regions were affected (lost) in UC Progressors but not in UC patients who were neoplasia free. Loss of heterozygosity at 6q27 has been described in ovarian and other cancers, while the 2q14 region has been implicated in prostate and sporadic colon cancers. Both regions are likely to contain tumor-suppressor genes. In conclusion, the genomic instability in UC Progressors can occur in regions that are susceptible to change and are locations of putative tumor-suppressor genes.

Colitis, Ulcerative↗
PubMed2004

Changes in ground reaction force during jump landing in subjects with functional instability of the ankle joint.

OBJECTIVE: To identify changes in ground reaction force during jump landing in subjects with functional instability of the ankle joint. DESIGN: Comparison of ground reaction force during jump landing between subjects with functional instability and healthy controls. BACKGROUND: We have recently demonstrated significantly altered patterns of ankle and knee movement immediately pre- and post-impact in subjects with functional instability compared to healthy controls. We now examine the changes in timing and magnitude of forces sustained by the unstable ankle during jump landing. METHODS: Fourteen subjects with unstable ankles and 10 age, sex and activity matched controls performed five single leg jumps onto a force platform whilst ground reaction forces were sampled. Timing and magnitudes of forces during the first 150 ms following impact were analysed and compared between groups. RESULTS: Lateral and anterior force peaks occurred significantly earlier in subjects with functional instability. Significant differences were seen between groups' time-averaged vertical, frontal and sagittal components of ground reaction force. These ranged from 5% (frontal force) to 100% (vertical force) of body mass. These changes occur immediately post-impact and too early for reflex correction/modification. CONCLUSIONS: The disordered force patterns observed in subjects with functional instability are likely to result in repeated injury due to significant increase in stress on ankle joint structures during jump landing. We suggest that they are most likely to result from deficits in feed-forward motor control. RELEVANCE: These results identify the potentially injurious nature of the changes in the forces applied to the unstable ankle joint during jump landing. The timing of these changes suggests that they are caused by a motor control deficit. Treatment approaches aimed at retraining feed-forward control of ankle joint movement could succeed in restoring more normal patterns of force absorption and reduce the occurrence of repeated micro-trauma to ankle structures.

Adaptation, Physiological↗
PubMed2005

Osteoarthritis following shoulder instability.

The association between shoulder instability and the development of glenohumeral osteoarthritis has not been well studied in the literature. It is clear that some degree of chondral damage is associated with instability, and there appears to be an increased risk of developing symptomatic osteoarthritis and ultimately requiring a shoulder arthroplasty in patients with a history of instability. More study is needed to define the relationship between the early onset of radiographically or arthroscopically diagnosed arthritic changes and clinically significant osteoarthritis. Surgical procedures to correct instability are known to put patients at risk for glenohumeral arthritis if they limit external rotation or if hardware migrates into the joint. Total shoulder replacement is an appropriate treatment for advanced, symptomatic osteoarthritis arising in shoulders with a history of instability. Outcomes are generally satisfactory, although not as good as in patients with primary osteoarthritis, and there is a higher risk of revision surgery.

Arthroplasty↗
PubMed2006

Diagnosis and management of traumatic and atraumatic hip instability in the athletic patient.

Although relatively uncommon compared with the shoulder, hip instability can be a source of significant disability and is a commonly unrecognized injury. Hip instability can be traumatic or atraumatic in origin. Our understanding and treatment plan for hip instability due to traumatic events is well established. However, our understanding and treatment modalities for hip instability due to atraumatic events or repetitive motion in high level athletes are not as well defined. In this article, we will review the spectrum of traumatic and atraumatic hip instability and discuss the relevant anatomy, history, and physical examination findings, imaging studies, and treatment options with a focus on hip arthroscopy, and review of the literature.

Arthroscopy↗
PubMed2004

[Genomic instability and male infertility].

Knowledge of the human genome has opened the genomic era. The genome instability, its causes and the possible consequences especially about fertility start to be understood. This instability can be observed on chromosome structure but also on genes. Different chromosomes rearrangements involved in infertility including translocations and Y chromosome deletions are described. The Y chromosome is a model of instability, and this instability is the source of its evolution. All those rearrangements are the results of illegitimate recombinations between homologous sequences. On genes we find punctual and dynamic mutations, polymorphisms and epigenetic abnormalities. They all are the results of ADN replication mistakes not corrected by the cellular machine. This machinery is the guardian of the genome integrity and in case of abnormality the programmed cellular death is induced. The knowledge of all these instability mechanisms is essential to appreciate the risk for the offspring after intracytoplasmic sperm injection. Indeed we go round physiological barriers without a complete understanding of the mechanisms involved. Thus, this is an important challenge for research teams but also for all assisted reproduction centers, dealing with ART. Genome is unstable - the very basis of its evolution. But this is also the cause of mistakes with pathological consequences like infertility and mental retardation.

Chromosomes, Human, Y↗
PubMed2004

The role of the dorsal intercarpal ligament in dynamic and static scapholunate instability.

PURPOSE: Scapholunate instability (SLI) is the most common carpal instability. Recent studies have suggested that the dorsal intercarpal (DIC) and the dorsal radiocarpal ligaments play an important role in stabilization of the scaphoid and lunate. Differences between dynamic SLI and static SLI with a dorsal intercalated segment instability (DISI) are clearly described in the clinical literature; however, there has never been a clear explanation of the anatomic differences. This study describes the role of the DIC in the development of dynamic and static SLI with DISI in a cadaver model. METHODS: Five fresh cadavers were studied radiographically and by 3-dimensional digitization. Six increasing stages of instability were developed by sectioning progressively the following structures: the dorsal capsule, the palmar and proximal (membranous) portion of the scapholunate interosseous ligament, the DIC from its insertion on the scaphoid and trapezium, the dorsal scapholunate interosseous ligament from the scaphoid, the DIC ligament from its attachment on the lunate, and the lunotriquetral interosseous ligament. RESULTS: The scaphoid position and the scapholunate gap changed significantly after sectioning the entire scapholunate interosseous ligament and DIC from the scaphoid when a 5-kg load was applied. The lunate position was unchanged in both the loaded and the unloaded conditions. After detaching the DIC from the lunate, both the scaphoid and lunate moved and the scapholunate gap increased significantly in both loaded and unloaded conditions and showed a DISI deformity. CONCLUSIONS: This study describes an anatomic difference between dynamic and static scapholunate instability. Complete disruption of the scapholunate ligament did not result in the development of a static collapse of the lunate. The DIC had an important role in stabilizing the scaphoid and lunate and preventing DISI deformity. This study suggests that in the clinical setting the DIC ligament should be assessed intraoperatively and consideration should be given to repair and/or reconstruction of the DIC ligament attachments to both the scaphoid and the lunate.

Aged↗