Modification of the Constant-Murley shoulder score-introduction of the individual relative Constant score Individual shoulder assessment.

The Constant-Murley shoulder assessment score has proven to be a valuable diagnostic instrument. Thus, in the literature it has been mentioned that the clinical accuracy of this score varies especially when comparing patients in larger, inhomogeneous patient groups. The "relative Constant score" (CS(rel)) tries to minimize these problems by using reference parameters out of healthy age and gender related control groups. The authors of this study tried to show that it is even more accurate to use the functional performance of the uninjured collateral shoulder of the same individual as reference, introducing the "individual relative Constant score" (CS(indiv)). The CS(indiv) and the CS(rel) were compared for 125 consecutive patients with shoulder disorders, and a group of 125 healthy volunteers as a control group. In a non-parametric comparison of the reciever operating characteristics the CS(indiv) shows the higher ability to discriminate between patients and healthy volunteers (p=0.004). This indicates that the individual relative Constant score gives a more accurate view about the functional result for shoulder disorders. It is expected to be more reliable for larger and incoherent patient populations, because specific interindividual differences, regarding the patient's age, gender and constitution are eliminated as well as other individual physiological parameters.