Does the Beighton Score Correlate With Specific Measures of Shoulder Joint Laxity?

Background: Evaluation of shoulder joint laxity is an important component of the shoulder examination, especially in the setting of shoulder instability. Measures of generalized joint laxity, particularly the Beighton score, are often recorded and used to help make management decisions in these cases. However, no evidence is available to show that the Beighton score corresponds to specific measures of shoulder joint laxity. Purpose: To assess the correlation between the Beighton score and validated measures of shoulder joint laxity. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 160 participants (age range, 16-35 years) with no history of shoulder joint abnormality were examined. The Beighton score, glenohumeral external rotation (standing and lying), glenohumeral abduction, and the sulcus sign were recorded. The relationship between the Beighton score and each measure of shoulder joint laxity was assessed. Results: A high proportion of participants (34%) had a Beighton score of 4 or higher. Rates of positive shoulder laxity tests were lower (11%-19%). A positive Beighton score was a poor predictor of abnormal shoulder laxity, with low sensitivity (range, 0.40-0.48) and low positive predictive values (range, 0.13-0.31). Spearman correlation coefficients demonstrated poor correlation between the Beighton score and all measures of shoulder joint laxity when assessed as continuous variables (range, 0.29-0.45). Conclusion: The Beighton score has poor correlation with specific measures of shoulder joint laxity and should not be considered equivalent to these tests as a method of clinical assessment.

Effect of Hormone Therapy on Tensile Strain of the Macaque Inferior Glenohumeral Ligament

The effect of hormone treatment on the material properties of ligaments has been extensively studied for the anterior cruciate ligament (ACL). However, there have been few studies on the effects of hormones on the material properties of the shoulder. Shoulder ligaments contribute to overall shoulder stability, and a change in ligament properties could contribute to a change in overall shoulder laxity. Cynomolgus monkeys have served as nonhuman primate models in studies examining the effects of hormone replacement therapy on the cardiovascular system, as well as serving as a model for menopause, reproductive support structures, the knee joint and shoulder joint. The cynomolgus macaques are commonly used for studies involving hormone replacement therapy because they have 28-day menstrual cycles with very similar hormonal patterns to that of women. This study uses female cynomologus macaque (Macaca fascicularis) monkeys as an animal model of the human shoulder to determine if estrogen has an effect on the strain distribution of the inferior glenohumeral ligament (IGHL).

Anterior Shoulder Laxity Is Not Correlated with Medial Elbow Laxity in High School Baseball Players

Context:Uninjured baseball players have been shown to have increased anterior glenohumeral joint laxity, which may result in adaptive changes at the medial elbow.Objective:To determine the relationship between anterior shoulder laxity and medial elbow laxity in both arms of baseball and nonbaseball high school athletes and compare the laxity of dominant and nondominant shoulders and elbows of high school baseball and nonbaseball players.Design:Cohort design.Setting:Local high schools.Participants:Thirty healthy high school male athletes.Outcome Measures:Anterior shoulder and medial elbow laxity measurements were taken bilaterally with the Ligmaster™.Results:Dominant and nondominant shoulder laxity was significantly greater in the nonbaseball players than the baseball players. No other significant relationships existed.Conclusions:High school baseball players exhibit less anterior shoulder laxity than do nonbaseball players. No relationship exists between anterior shoulder and medial elbow laxity in high school baseball players.