抄録
Several causes were reported on suprascapular nerve(SSN) palsy. To diagnose SSN palsy, usually these findings were useful as follows: atrophy of the supraspinatus and infraspinatus muscle, muscle weakness of ABD & ER, no or small rotator cuff tear, and abnormal findings on EMG. However, it was difficult to diagnose SSN palsy in patients with massive rotator cuff tear. The objectives of this study were to investigate the effectiveness of a sensory disturbance on the posterior shoulder in diagnosing SSN palsy in patients with rotator cuff tear. 16 shoulders in 16 cases were involved in this study. They had sensory disturbance of the posterior aspect of the shoulder and received arthroscopic release of the suprascapular ligament. The average age was 65 years old. 10 males and 6 females were included. The size of rotator cuff tear showed incomplete tear in 3 shoulders, small tear in three, medium tear in 2, large tear in 1 and massive tear in 7. Preoperative sensory disturbance, the results of EMG analysis, occupation ratio of supraspinatus/infraspinatus muscle in MRI, and outcomes of sensory disturbance were evaluated. Sensory disturbance in the posterior aspect of the shoulder was observed in all cases. In EMG examinations, there was no difference compared with the normal side except 2 shoulders. The occupation ratio was averaged 46.7% in supraspinatus muscle and 68.5% in infraspinatus muscle. Sensory disturbance disappeared in 14 shoulders within approximately 2 weeks. The remaining 2 shoulders showed improvement of range and VAS scale. We performed arthroscopic release of SSN in 16 shoulders with the sensory disturbance at posterior aspect of the shoulder. All cases were improved after the surgery. The sensory disturbance at posterior aspect of the shoulder is useful in diagnosis of SSN palsy, especially in a case with massive rotator cuff tear.
