Axis doctors Noah Whitehead and Mark Fulcher have recently completed a research project that has explored the relationship between the Beighton score and validated measures of glenohumeral joint laxity. This research, which has been accepted for publication in the Orthopaedic Journal of Sports Medicine, has shown that there is no correlation between these measures. This essentially means that the Beighton score may not be a useful indicator of joint laxity and should be used with caution when planning a patient’s treatment.
Joint laxity refers to the flexibility of joints and is usually defined by an increase in range of motion. Generalised joint laxity is a condition in which the range of motion across various joints in an individual is increased compared to population norms. This may be a reflection of an underlying connective tissue disorder but is most often not related to a pathological process. The Beighton score has become the most widely recognised measure of the presence and extent of the condition.
A number of studies have demonstrated higher rates of certain musculoskeletal injuries, particularly ankle sprains and anterior cruciate ligament rupture in the knee, in subjects with generalised joint laxity. The association with the risk of shoulder injury is however much less clear. There is an important association between specific measures of shoulder laxity and the risk of recurrent shoulder instability. The presence (or absence) of shoulder laxity may, therefore, help determine whether the patient is managed surgically as well as the type of procedure performed.
For the Beighton score to be considered relevant to the assessment of shoulder laxity, data is required that demonstrates a significant correlation between these variables. It was the purpose of our study to compare the Beighton score with validated measures of shoulder laxity. We hoped to determine whether the Beighton score corresponds with these measures, which may help to clarify whether this is an appropriate tool to guide management decisions in patients presenting with shoulder instability. We compared the Beighton score with specific and validated measures of shoulder laxity – external rotation (measured upright and supine), glenohumeral abduction and the sulcus sign, in 160 participants who had no history of shoulder joint pathology.
The study has shown that a Beighton score of 4 or greater was poorly sensitive for predicting the presence of any abnormal shoulder laxity value (positive predictive value 0.25). When the Beighton score and individual shoulder laxity measures were compared as continuous variables, a weak correlation was demonstrated (range 0.29 – 0.45). These results have implications for clinical practice. Based on this data the Beighton score cannot be considered as an equivalent alternative to shoulder laxity tests. Clinicians should be cautious when using the Beighton score as part of the shoulder laxity examination and when using this information to plan the management of shoulder joint instability.