Introduction: The Constant Score Functional Assessment (CS) is now the standard method of assessing shoulder disability in Europe. Previous studies have indicated that the CS values associated with a full-thickness rotator cuff tear (RCT) are lower than for normal shoulders. This study was designed to investigate which parameters of the CS were most influenced by the presence of a RCT. As ultrasonograpy has now been shown to have a high accuracy for diagnosing full-thickness RCTs it was used to establish the diagnosis.

Methods: 28 patients attending the Shoulder Clinic were invited to take part in this study for which Local Ethics Committee approval had been obtained. The majority of patients had a painful shoulder on at least one side. All patients had a CS carried out with the “Strength” measurement made in 3 ways – 1) maximum force using a fixed spring balance – FSB(max); 2) maximum force using a commercial myometer – M(max); 3) mean force from 2 to 4 seconds using a commcercial Myometer – M(mean). The CS was measured with no knowledge of the patient’s history or diagnosis and blinded to the state of the rotator cuff. The patients were then assessed using ultrasonograpy of the shoulder (Diasus with an 8–16MHz head) to establish the presence of a full-thickness RCT.

Results: The CS Values for the left and right shoulders have been analysed separately.

The results have also been analysed for each part of the Constant Score – Pain, Activities of Daily Living, Range of Movement and Strength and these will be presented.

Discussion: It was anticipated that subjects with a RCT would be found to be weaker and have a reduced CS in an affected shoulder. This was found to be the case for the left shoulder but not for the right. The reasons for this will be discussed. The abnormally low CS for the normal right shoulders (Group 1) will also be explored.

Conclusion: The CS may be a valuable method of identifying those patients with a RCT. This study indicates that a more careful evaluation of “Strength” measurements still needs to be undertaken.

Introduction: This study was designed to investigate which parameters of the Constant Score are most influenced by the presence of a Rotator Cuff Tear (RCT).

Methods: 28 patients attending the Shoulder Clinic took part in this study for which Ethics approval had been obtained. Strength measurements were assessed in three ways: 1) maximum force using a fixed spring balance (FSB) 2) maximum force using the Nottingham Mecmesin Myometer 3) mean force during 2nd to 4th seconds using Nottingham Myometer. The CS assessor was blind to the volunteer’s history and state of their rotator cuff. Ultrasonography was used to establish the presence of a full-thickness RCT.

Results: The CS values for the left and right shoulders were analysed separately. No statistically significant difference (p> 0.05) was found between shoulders with a RCT and without a RCT in the pain, ADL and ROM parameters. Left shoulders with a RCT scored significantly different strength scores to those without (p< 0.05) but this significance was not seen in the right shoulders (p> 0.05). Shoulder strength measurements were highest with the FSB and lowest when measured using the mean force.

Discussion: The results obtained so far suggest that a shoulder with a full-thickness tear of the RC may obtain a significantly lower strength score than a normal shoulder. It does not suggest that any of the other three parameters of the CS can indicate the presence of a tear.

Conclusion: A reduction of shoulder strength alone might be a good indicator of a full-thickness RCT. However, this study indicates the importance of standardising the method of shoulder strength assessment for the Constant Score.