Histologic evaluation of thermal capsulorrhaphy of human shoulder joint capsule with monopolar radiofrequency energy during short- to long-term follow-up.

PURPOSE: The purpose of this study was to evaluate the histologic morphology of human shoulder joint capsule after thermal capsulorrhaphy with monopolar radiofrequency energy (mRFE) during short- to long-term follow-up.

METHODS

This study comprised 27 patients who received an arthroscopic mRFE thermal capsulorrhaphy and 10 patients without mRFE treatment serving as the control group. Biopsy samples from 3 locations (anterior-superior, anterior-inferior, and posterior-medial) of the shoulder joint capsule were harvested from both the mRFE-treated patients and the control patients. The follow-up time for the mRFE treatment ranged from 3.5 to 62 months, which was divided into 3 groups: short, 3.5 to 12 months; medium, 14 to 25 months; and long, 31 to 62 months. The biopsy samples were analyzed via a histologic scoring system, evaluating an intact synovial layer, subsynovial edema, collagen morphology, cellularity, vascularity, and inflammatory cells. Histologic scores among each follow-up group were compared with each other and with those in the control group.

RESULTS

There were no significant differences in the histologic categories of intact synovial layer, subsynovial edema, collagen morphology, and inflammatory cells among the control and mid- and long-term mRFE groups. The short-term mRFE group had greater increased cellularity and vascularity compared with the mid- and long-term groups, which progressively improved toward the appearance in the normal control group with time.

CONCLUSIONS

After mRFE capsulorrhaphy, histologic analysis revealed that the mRFE-treated shoulder joint capsule had almost returned to normal, except for persistent cellularity and increased vascularity, which were present at up to 5 years after this procedure.

LEVEL OF EVIDENCE: Level III, therapeutic case-control study.