Objective: To compare prospectively isokinetic shoulder strength before and 3 months after shoulder stabilization by the Latarjet procedure indicated for the treatment of recurrent dislocation.
Method: Twenty-five subjects, 23+/-6 years old, with anterior unidirectional recurrent shoulder dislocation, underwent isokinetic concentric (con) and eccentric (ecc) measurement of lateral rotators (LR) and medial rotators (MR) of both shoulders at the angular speed of 60 and 120 degrees par second. Evaluation was carried out in the scapular plane with the patient in a sitting position one month before and 3 months after shoulder stabilization by the Latarjet technique. We calculated the concentric ratio LR/MR and mixed ratios LR(ecc)/MR(con) and LR(con)/MR(ecc).
Results: Before surgery, the rotator peak torque for the operated shoulder side was similar to that of the healthy shoulder side. The concentric ratio for the healthy shoulder side was higher because the lateral rotators were slightly weaker on the recurrent-dislocated shoulder side. Three months after shoulder stabilization by the Latarjet technique, for the operated shoulder side, the isokinetic concentric torque of rotators was similar to that before surgery. For the operated shoulder side, only the eccentric torque of medial rotators was significantly lower after surgery than before surgery and lower than that for the healthy shoulder side (9 to 15%). Ratios did not differ before and after surgery.
Conclusion: Three months after surgery with Latarjet technique for recurrent dislocated shoulder, operated shoulders showed a slight strength deficit as compared with healthy shoulders. The concentric deficit after surgery was not significantly different from that before surgery. This result could be explained by strengthening exercises performed during the shoulder rehabilitation program. However, the eccentric strength deficit of medial rotators of the operated shoulder is certainly associated with the opening and stitching of the sub-scapular muscle necessary for the shoulder stabilization.