Acute Anterior Shoulder Instability Research Articles

Effect of Time And Contrast Use for Magnetic Resonance Imaging in Acute Anterior Shoulder Instability: Determining the Accuracy Of Labrum Tear Size

Effect of Time And Contrast Use for Magnetic Resonance Imaging in Acute Anterior Shoulder Instability: Determining the Accuracy Of Labrum Tear Size

Risk Factors for Anterior Glenohumeral Instability

Background: While anterior glenohumeral instability has been shown to be common in young athletes, the risk factors for injury are poorly understood. Purpose/Hypothesis: To determine the modifiable and nonmodifiable risk factors for anterior shoulder instability in a high-risk cohort. The hypothesis was that specific baseline factors would be associated with the subsequent risk of injury. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: We conducted a prospective cohort study in which 714 young athletes were followed from June 2006 through May 2010. Baseline assessments included a subjective history of instability, physical examination by a sports medicine fellowship–trained orthopaedic surgeon, range of motion, strength with a handheld dynamometer, and bilateral noncontrast shoulder magnetic resonance imaging (MRI). A musculoskeletal radiologist measured glenoid version, glenoid height, glenoid width, glenoid index (height-to-width ratio), glenoid depth, rotator interval (RI) height, RI width, RI area, RI index, and the coracohumeral interval. Subjects were followed to document all acute anterior shoulder instability events during the 4-year follow-up period. The time to anterior shoulder instability event during the follow-up period was the primary outcome of interest. Univariate and multivariable Cox proportional hazards regression models were used to analyze the data. Results: Complete data were available for 714 subjects. During the 4-year surveillance period, there were 39 anterior instability events documented at a mean of 285 days. While we controlled for covariates, significant risk factors of physical examination were as follows: apprehension sign (hazard ratio [HR], 2.96; 95% CI, 1.48-5.90; P = .002) and relocation sign (HR, 4.83; 95% CI, 1.75-13.33; P = .002). Baseline range of motion and strength measures were not associated with subsequent injury. Significant anatomic risk factors on MRI measurement were glenoid index (HR, 8.12; 95% CI, 1.07-61.72; P = .043) and the coracohumeral interval (HR, 1.20; 95% CI, 1.08-1.34; P = .001). Conclusion: This prospective cohort study revealed significant risk factors for shoulder instability in this high-risk population. Physical examination findings of apprehension and relocation were significant while controlling for history of injury. The anatomic variables of significance were not surprising—tall and thin glenoids were at higher risk compared with short and wide glenoids, and the risk of instability increased by 20% for every 1-mm increase in coracohumeral distance.

Aircast Award for Basic Science - Return to Play Following In-season Anterior Shoulder Instability: A Prospective Multicenter Study

Objectives:There is no consensus on the optimal treatment of young in-season athletes with anterior shoulder instability and limited data are available to guide return to play and treatment. The purpose of this study was to examine the likelihood of return to sport following an in-season shoulder instability event based on the type of instability (subluxation vs. dislocation). Additionally, injury factors and patient reported outcome scores administered at the time of injury were evaluated to assess the predictability of eventual successful return to sport and time to return sport during the competitive season following injury.Methods:Over two academic years, 45 contact intercollegiate athletes were prospectively enrolled in a multicenter observational study to assess return to play following in-season anterior glenohumeral instability. The primary outcomes of interest were the ability to return to sport and time lost from sport following an acute anterior shoulder instability event. Baseline data collection included sport played, previous instability events, direction of instability, and type of instability (subluxation or dislocation). Patient reported outcome scores specific to the shoulder were obtained at the time of injury and included the Western Ontario Shoulder Instability Index (WOSI), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test (SST), and American Shoulder and Elbow Score (ASES). All observed patients underwent a standardized accelerated rehabilitation program without shoulder immobilization, following the initial shoulder instability event. Subjects were followed during the course of their competitive season to determine return to play success and recurrent instability.Results:Thirty-three of 45 (73%) athletes returned to sport for either all or part of the season after a median 5 days lost from competition (IQR=13)(Fig 1). Of the 33 athletes returning to in-season sport following an instability event, 63% (22/33) completed the season. Athletes with a subluxation were 5.3 times more likely (OR=5.32, 95%CI: 1.00, 28.07, p=0.049) to return to sport following an initial in-season shoulder instability event when compared to those with dislocations. Logistic regression analysis suggests that the WOSI (OR=1.05; 95% CI 1.00, 1.09; p=0.037) and SST (OR=1.03, 95% CI 1.00, 1.05; p=0.044) administered after the initial instability event are predictive of ability to return to play . For every 1 point higher the WOSI scaled score at the time of injury, the athlete was 5% more likely to return to play during the same season. Time loss from sport following a shoulder instability event was inversely correlated with the WOSI (p=0.039), SST (p=0.007), and ASES (p=0.02) scores at the time of initial injury. The SST demonstrated the strongest correlation with time lost from sport, and for every 10 points higher the SST scale score was at the time of injury an athlete returned to sport 1.2 (95%CI: 0.4, 1.9) days sooner (p=0.004). Based on the logistic regression analysis, time lost from sport is predicted using the SST score after the initial instability event (Table 1).Conclusion:In the largest prospective study evaluating shoulder instability in mid-season contact athletes, we demonstrate that 73% of athletes return to play after one week. While the majority of athletes who return to sport complete the season, recurrent instability events are common regardless of whether the initial injury was a subluxation or dislocation.

Risk Factors for Anterior Glenohumeral Instability

Objectives:While anterior glenohumeral instability has been shown to be common in young athletes, the risk factors for injury are poorly understood. The elucidation of risk factors is critical to help develop prevention strategies. We hypothesized that specific modifiable and non-modifiable factors at baseline would be associated with the subsequent risk of injury in a cohort of young athletes.Methods:We conducted a prospective cohort study in which 714 young athletes were followed from June 2006 through May 2010. Baseline assessments included a subjective history of instability, physical examination by a sports-trained orthopaedic surgeon, range-of-motion, strength with a hand-held dynamometer, and bilateral noncontrast shoulder MRI. A musculoskeletal radiologist measured glenoid version, glenoid height, glenoid width, glenoid index (height-to-width ratio), glenoid depth, rotator interval (RI) height, RI width, RI area, RI index, and the coracohumeral interval. Subjects were followed to document all acute anterior shoulder instability events during the 4 year follow-up period. The time to shoulder instability event during the follow-up period was the primary outcome of interest. Univariate and multivariable Cox proportional hazards regression models were used to analyze the data.Results:We obtained complete data on 714 subjects. During our 4 year surveillance period, there were 38 anterior instability events documented. While controlling for covariates, significant risk factors of physical exam were: apprehension sign HR=2.96 (1.48, 5.90, p=0.002) and relocation sign HR=4.83 (1.75, 13.33, p=0.002). Baseline range-of-motion and strength measures were not associated with subsequent injury. Significant anatomic risk factors on MRI measurement were glenoid index HR=8.12 (1.07, 61.72) p=0.043 and the coracohumeral interval HR=1.20 (1.08, 1.34, p=0.001).Conclusion:This prospective cohort study revealed significant risk factors for shoulder instability in this high-risk population. While modifiable risk factors such as strength and range-of-motion were not associated with subsequent instability, some non-modifiable risk factors were. That the exam findings of apprehension and relocation were significant while controlling for prior history of injury suggests that patients may be unaware of prior instability episodes. The anatomic variables of significance are also not surprising - tall and thin glenoids were at higher risk compared to short and wide glenoids; and the risk of instability increased by 20% for every 1mm increase in coracohumeral distance.

Management of Acute Anterior Shoulder Instability in Adolescents

Traumatic anterior shoulder instability is a common orthopaedic problem encountered in adolescents. Approximately 90% of patients who experience their first traumatic instability event before the age of 20 will go on to have recurrent episodes if appropriate interventions are not pursued. Acute shoulder dislocations should be reduced promptly. Definitive management may be surgical or nonsurgical. Adequate assessment of concomitant pathology is essential in planning management and optimizing outcomes. Ultimately, the management algorithm will depend on the patient's age, type of sport, timing in season, and concomitant pathology.

Management of Acute Anterior Shoulder Instability in Adolescents

Management of Acute Anterior Shoulder Instability in Adolescents

First-time anterior shoulder dislocations: has the standard changed?

The traditional treatment of a first-time anterior shoulder dislocation of reduction and a period of immobilisation should be challenged. The purpose of this review is to assimilate and present the...

The Spectrum of Lesions and Clinical Results of Arthroscopic Stabilization of Acute Anterior Shoulder Instability

PurposeThe purpose of this study is to investigate and analyze accom-panying lesions including injury types of anteroinferior labrum lesion in young and active patients who suffered traumatic anterior shoulder dislocation for the first time.Meterials and MethodsThe study used magnetic resonance angiography (MRA) to 40 patients with acute anterior shoulder dislocation from April 2004 to April 2008, and of those, 36 with abnormal MRA finding were treated with arthroscopy.ResultsThere was a total of 25 cases of anteroinferior glenoid labrum lesions. A superior labrum anterior-posterior lesion (SLAP) lesion was observed in 8 cases. For bony lesions, 22 cases of Hill-sachs lesions, 4 cases of lesions in greater tuberosity fracture of humerus, and 4 cases of loose body were found. For lesions involving rotator cuff, partial articular side rupture was found in 2 cases and 2 cases were found to have a complete rupture.ConclusionUnder MRA and arthroscopy performed on patients with acute anterior shoulder dislocation, it was observed to have varying types of anteroinferior labrum lesions such as Perthes, Bankart, ALPSA, and bony Bankart lesion. that MRA is a remar-kably useful tool to classify various lesions in acute anterior dislocation of the shoulder and to make a diagnosis, making it a useful tool to decide a treatment method while consulting patients and their families.

Selective Referral and the "A" Doctor

The traditional treatment of a first-time anterior shoulder dislocation of reduction and a period of immobilisation should be challenged. The purpose of this review is to assimilate and present the current literature on acute anterior shoulder instability. This involves consideration of the pathoanatomy, natural history and the more recent evaluation of treatment outcomes, which appropriately incorporate quality of life measures in addition to recurrences. There is ample evidence to consider primary stabilisation as an option for treatment in the high-risk group, less than 25 years of age.