Comparison of Scapular Kinematics and Range of Motion Between Normal and Post-operative Shoulders Following Subpectoral Biceps Tenodesis

OBJECTIVES: Though many surgeons advocate biceps tenodesis for treatment of intra-articular biceps pathology, little is known about the biomechanical effects this may have on the glenohumeral joint. The purpose of the present study is to describe in detail the effect of biceps tenodesis on shoulder muscle strength, range of motion, and scapular motion. We hypothesized that post-surgical shoulders would not show significant differences in range of motion, strength, and kinematics when compared to the uninvolved shoulder. METHODS: 22 patients underwent a subpectoral biceps tenodesis and were evaluated at least 6 months following the procedure. We evaluated range of motion, strength, and scapular kinematics. Measures included glenohumeral abduction, internal and external rotation, elbow flexion and extension, internal and external rotation strength, and scapular kinematics. Subjects also completed the DASH questionnaire. RESULTS: The average DASH score was 5.3 +/- 6.3 following surgery. The post-surgical shoulder showed a significant 8.3 degree decrease (p = 0.003) in glenohumeral abduction external rotation compared to the uninvolved shoulder. However, there were no significant differences in other measurements of glenohumeral motion or strength. Kinematic data revealed significantly increased scapular internal rotation (p = 0.02) and anterior tipping (p = 0.019) while reaching for the contralateral shoulder. CONCLUSION: The majority of outcome measures were equivalent when comparing the post-surgical and uninvolved shoulder function and biomechanics. Significant findings include a loss of glenohumeral abduction external rotation after surgery as well as anterior scapular tipping and rotation while reaching for the contralateral shoulder. Overall, subjects expressed minimal disability following surgery, as evidenced by their DASH scores. Nonetheless, we recommend a vigilant focus on regaining external rotation following open subpectoral biceps tenodesis in an attempt to limit or prevent loss of shoulder motion.