LAUSR

BACKGROUND Glenoid bone loss is one of the main challenges in revision of failed shoulder arthroplasties. The concept of a hemireverse is to implant the glenoid baseplate and the glenosphere to protect the glenoid reconstruction to allow it to heal, and to preserve the joint space for a potential second staged humeral component implantation. The purpose of this study was to report on the results of this procedure. METHODS Fifteen patients, eight with a failed anatomic total shoulder arthroplasty (TSA), three with a failed reverse shoulder arthroplasty (RSA), three with a failed humeral hemiarthroplasty and one with a cement spacer due to sepsis after a TSA underwent revision to hemireverse. After complete removal of the initial prosthesis, all patients had glenoid reconstruction with bone grafting, and implantation of a reverse arthroplasty baseplate and glenosphere. In all cases, a humeral implant was not placed. The patients were prospectively followed and had complete pre and postoperative clinical and radiological studies at a minimum of two years after the last surgery. RESULTS Thirteen hemireverse implants and glenoid bone grafts healed (86%) and remained radiographically stable. One hemireverse construct migrated and became mechanically loose, which was attributed to absent fixation of the central post in the native glenoid bone. One patient developed an implant related infection and underwent irrigation and débridement and revision to a resection arthroplasty. After documented radiographic healing of the hemireverse glenoid reconstruction, five patients underwent a second stage revision to reverse with insertion of a humeral component at a median of six months (interquartile range, 6 to 8 mo.). In this group, the median follow-up was 73 months (IQR, 45 to 153 mo.), the median Constant score was 48 (IQR, 41 to 56), the median active forward elevation (AFE) was 135° (IQR, 100 to 150°) and the median Subjective Shoulder Value (SSV) was 50% (IQR, 50 to 60%). Of the nine remaining hemireverse patients, the median follow-up was 38 months (IQR, 29 to 60 mo.), the median Constant score was 41 (IQR, 38 to 46), the median AFE was 100° (IQR, 80 to 100°) and the median SSV was 50% (IQR, 40 to 60%). CONCLUSION Hemireverse is an effective revision procedure to reconstruct the severely deficient glenoid. The hemireverse may function as the definitive procedure, with satisfactory outcomes. Additionally, the hemireverse can undergo second stage revision to total reverse once imaging confirms bonegraft and construct stability.