Risk Factors for Complications and Revision Surgery after Anatomic and Reverse Total Shoulder Arthroplasty
These authors evaluated patient-specific, implant-specific and technique-specific risk factors for intra operative complications, postoperative complications, and the occurrence of revisions after 2964 anatomic ( aTSA) and 5616 reverse (rTSA) total shoulder arthroplasties.
aTSA patients had an intraoperative complication rate of 0.6% while rTSA patients had an intraoperative complication rate of 0.8%. Female gender and previous shoulder surgery were identified as significant risk factors
aTSA patients had a per year adverse even rate of 2.8% per year while rTSA patients had a per year adverse event rate of 3.6%. Younger age, rheumatoid arthritis, and previous shoulder surgery were noted to be risks factors. The most common aTSA complications were rotator cuff tear and/or subscapularis failure and aseptic glenoid loosening. Subscapularis failure was the most common complication in women, while aseptic glenoid loosening was the most common complication in men. The most common rTSA complications were acromial and scapular spine fractures and pain/pain after a fall. Acromial and scapular spine fractures were the most common complication in women, while instability was the most common complication in men.
aTSA patients had a per year revision rate of 1.8% per year while rTSA patients had a per year revision rate of 1.2% Younger age, more glenoid retroversion, larger humeral stem size, larger humeral liner thickness/offset, larger glenosphere diameter, and more intra operative blood loss were noted to be risk factors.
Comment: This is a large study of adverse events for anatomic and reverse shoulder arthroplasties. It emphasizes the importance of surgical technique (care in subscapularis and rotator cuff management as well as glenoid fixation for aTSA and prosthesis selection and positioning for rTSA) in minimizing adverse outcomes.
These results can be compared to those of another recent article:
Analysis of 4063 complications of shoulder arthroplasty reported to the US Food and Drug Administration from 2012 to 2016
These authors point out that most of the literature on shoulder arthroplasty failure comes from high-volume centers and that these reports tend to exclude the experience of community orthopedic surgeons, who perform most of the shoulder joint replacements.
They analyzed the failure reports mandated by the US Food and Drug Administration for all hospitals. Each reported event from 2012 to 2016 was characterized by implant, failure mode, and year of surgery.
Although the percentage distribution among the different failure modes was relatively consistent over the years of this study, the percentage distribution of these failure modes differed substantially among different implant manufacturers.
For the 1673 anatomic arthroplasties, the most common failure modes were glenoid component failure (20.4%), rotator cuff/subscapularis tear (15.4%), pain/stiffness (12.9%), dislocation/instability (11.8%), infection (9%), and humeral component loosening (5.1%). The distribution of these complications remained consistent over the years of the study.
For the 2390 reverse arthroplasties, the most common failure modes were dislocation/instability (32%), infection (13.8%), glenosphere-baseplate dissociation (12.2%), failed/loosened baseplate (10.4%), humeral component dissociation/tray fracture (5.5%), difficulty inserting the baseplate (4.8%), and difficulty inserting the glenosphere (4.2%). The distribution of these complications remained consistent over the years of the study.
The percentage distribution of the failure modes also differed substantially from those published in a recent review of the literature.
Further clinical research is need to determine which surgical approaches are most successful for young patients, those with rheumatoid arthritis, prior shoulder surgery, and those with glenoid retroversion.
