Humeral stems in reverse total shoulder arthroplasty (RTSA) have steadily shrunk in length to conserve bone. For a study, researchers sought to evaluate the immediate postoperative radiographic appearance of short-length RTSA stems to that of standard-length RTSA stems.
A multicenter retrospective evaluation was conducted on patients who underwent RTSA utilizing a press-fit standard-length or short-length humeral implant with uniform geometry (Univers Revers or Revers Apex). Initial alignment and filling ratios were assessed using initial postoperative radiographs. Radiographs were also examined for early stress shielding and/or loosening symptoms. Scores for clinical outcomes and range of motion were also assessed.
In all, 137 short and 139 standard-length stems were examined. Initial radiographs revealed that the short-stem group had a considerably greater percentage of stems in neutral alignment (95.6% vs. 89.2%, P=0.045). The metaphyseal filling ratios were similar, while the short-stem group had a considerably greater diaphyseal filling ratio (57% vs. 34%, P<0.001). Short stems had less calcar osteolysis (2.2% vs 12.9%; P=0.001) and a lower total number of radiographic alterations (tuberosity resorption, lucencies, and subsidence) (0.7% vs 5.0%; P=0.033) than standard-length stems.
When compared to a standard-length stem, RTSA with a short-stem humeral implant result in superior radiographic outcomes, including low rates of loosening and subsidence at 1 year and less early calcar osteolysis.