The Cause and Treatment of Periarthritis of the Shoulder Based on Stages of Connective Tissue Healing

Abstract

Periarthritis of the shoulder is characterized by freezing phase, frozen phase, and thawing phase. However, the pathology of its clinical course is not clarified. Recent development of shoulder open surgery, arthroscopy, MRI and PET demonstrated that shoulders with persisting pain and contracture had hyperemia and edema of the joint capsule and subacromial bursa. Thus, we tried to elucidate clinical phases of frozen shoulder based on connective tissue repair and remodeling.
Early freezing phase of the shoulder is consistent with acute inflammatory phase of connective tissue repair. In this period, edema and hyperemia of the shoulder joint capsule appears with occurrence of shoulder pain (0 to 1 month from the onset). Late freezing phase of the shoulder is consistent with fibroplasias of connective tissue repair. In this period, infiltration of fibroblasts and new vessels in the capsule appears with progressive pain and reduction of range of motion (1 to 2 months from the onset). Freezing phase of the shoulder is consistent with consolidation stage of remodeling of connective tissue repair. In this period, fibrosis and thickening of the joint capsule appears with progressive contracture (2 to 6 months from the onset). Thawing phase of the shoulder is consistent with maturation stage of remodeling of connective tissue repair. In this period, remodeling of joint capsule appears with gradual relief from joint contracture (6 month to 1 year from the onset).
Joint capsule of the shoulder is known to have enough redundancy. However, if the inflammation of the capsule spreads all over the shoulder joint, fibrosis and production of collagen fibers in the capsule develops. Subsequent relief form joint contracture with remodeling of the capsule explains characteristic features of clinical staging of periarthritis of the shoulder. Comparing clinical stage and extent of connective tissue repair, theoretical back ground of physical therapy and surgical treatment is evident.