Most cases of square shoulder deformity have progressed to severely destructive total joint tuberculosis, and some patients have developed abscesses or sinus tracts, which are not difficult to diagnose. However, simple synovial tuberculosis, simple bone tuberculosis and early total joint tuberculosis are not easy to achieve early diagnosis. Clinical diagnosis of square shoulder deformity, there is a diagnostic method, that is, with the frozen shoulder and posterior dislocation of the shoulder joint differential diagnosis: 1, frozen shoulder: frozen shoulder: frozen shoulder is also known as frozen shoulder, adhesive shoulder osteoarthritis, fifty shoulders, and so on. It is due to the soft tissue lesions around the shoulder joint and cause shoulder joint pain and activity dysfunction. It occurs in patients over 40 years old, more women than men (about 3:1), and more left shoulders than right shoulders. It is characterized by the gradual increase of shoulder pain and shoulder dysfunction. After several months or even longer, the pain gradually subsides, the function slowly recovers, and finally cures itself. Posterior dislocation of shoulder joint: Posterior dislocation of shoulder joint is relatively rare, one of the reasons is that the back of shoulder joint is protected by strong muscle group, which is difficult to be dislocated backward; even if there is posterior dislocation, it is easy to be returned to the back due to the tension stress of backward muscle group, therefore, it is very rare to be seen in clinic.