Initial and 1-Year Radiographic Comparison of Reverse Total Shoulder Arthroplasty With a Short Versus Standard Length Stem.

INTRODUCTION

In an effort to preserve bone, humeral stems in reverse total shoulder arthroplasty (RTSA) have gradually decreased in length. The purpose of this study was to compare the immediate postoperative radiographic appearance of short-length with standard-length RTSA stems.

METHODS

Patients who underwent RTSA using a press-fit standard-length or short-length humeral implant with a consistent geometry (Univers Revers or Revers Apex) were evaluated in a multicenter retrospective review. Initial postoperative radiographs were used to assess initial alignment and filling ratios. In addition, radiographs were evaluated for early signs of stress shielding and/or loosening. Clinical outcome scores and range of motion were also evaluated.

RESULTS

Overall, 137 short-length stems and 139 standard-length stems were analyzed. Initial radiographs demonstrated a significantly higher percentage of stems placed in neutral alignment in the short-stem group (95.6% vs 89.2%, P = 0.045). Similar metaphyseal filling ratios were seen between groups, but a significantly higher diaphyseal filling ratio was observed in the short-stem group (57% vs 34%, P < 0.001). Less calcar osteolysis (2.2% vs 12.9%; P = 0.001) and fewer overall number of radiographic changes (tuberosity resorption, lucencies, and subsidence) (0.7% vs 5.0%; P = 0.033) were seen with short stems compared with the standard-length stems.

CONCLUSION

RTSA with a short-stem humeral implant demonstrates excellent radiographic outcomes, including low rates of loosening and subsidence at 1 year, with less early calcar osteolysis compared with a standard-length stem.

LEVEL OF EVIDENCE: III (Case-control).