Anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty for dislocation arthropathy yield comparable functional outcomes with the matched cohort

BackgroundThe aim of this study was to compare outcomes of anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) after prior shoulder stabilization versus matched cohorts without previous stabilization surgery. Hypotheses were as follows: (1) patients undergoing aTSA or rTSA after stabilization procedures would have worse outcomes than matched cohorts and (2) patients undergoing TSA would have better outcomes after soft-tissue stabilization procedures (aTSA_ST or rTSA_ST) than after bony stabilization procedures (aTSA_B or rTSA_B).MethodsRetrospective cohort study was performed comparing (1) 36 patients who underwent aTSA and (2) 32 patients who underwent rTSA with prior shoulder stabilization with 3-to-1 matched cohorts (based on age, gender, and follow-up length) with no prior shoulder instability or surgery. Baseline demographics, perioperative data, adverse events (AEs), radiographic outcomes, functional outcome scores, range of motion (ROM), and patient satisfaction were analyzed. Subgroup analyses compared patients who underwent aTSA_ST or rTSA_ST with patients who underwent aTSA_B or rTSA_B.ResultsThe postoperative AE rate was 8.3% and 4.6% in the aTSA group and matched cohort, respectively (P = .404), with a trend toward a significantly higher incidence of aseptic glenoid loosening in the aTSA group (8.3% vs. 1.9%, P = .067). Functional outcomes, ROM, and patient satisfaction did not differ at follow-up >4 years. In the subgroup analysis, two AEs required reoperation among 25 patients who underwent aTSA_ST versus one among 11 patients who underwent aTSA_B, all related to aseptic loosening. There was a trend toward greater functional outcomes and satisfaction among patients who underwent aTSA_ST. There was a trend toward a clinically significant difference in active abduction at final follow-up favoring aTSA_ST (128 vs. 108 degrees, P = .096).The postoperative AE rate was 6.3% and 4.2% among the rTSA group and matched cohort, respectively (P = .632). Functional outcomes, ROM, and patient satisfaction did not differ at 4-year follow-up. In the subgroup analysis, no AEs were reported among 18 patients who underwent rTSA_ST and 14 patients who underwent rTSA_B. A trend toward greater functional outcomes and patient satisfaction favored patients who underwent rTSA_B, who achieved greater improvements in ROM from baseline and greater ROM in all planes at the final follow-up.ConclusionBoth aTSA and rTSA are reliable options for the treatment of dislocation arthropathy in appropriately selected patients. aTSA and rTSA after prior shoulder stabilization procedures have nearly equal rates of AEs and yield similar clinical and functional outcomes as matched cohorts. There may be an increased risk of glenoid aseptic loosening in aTSA after prior shoulder stabilization. Functional outcomes tend to be greater for patients who underwent aTSA_ST than those for patients who underwent aTSA_B. On the contrary, rTSA may optimize postoperative function when performed for dislocation arthropathy after bony rather than soft-tissue stabilization procedures.Level of evidenceLevel III; Retrospective Cohort Design; Treatment Study