Patients that have intraoperative deviations in their preoperative plan have inferior clinical and radiographic outcomes after anatomic total shoulder arthroplasty.

Abstract

Three-dimensional, computed tomography, preoperative planning has become adopted among shoulder arthroplasty surgeons. Prior studies have not examined outcomes in patients in which the surgeon implanted prostheses that deviated from the preoperative plan compared to patients in which the surgeon followed the preoperative plan. The hypothesis of this study was that clinical and radiographic outcomes would be equivalent between patients undergoing anatomic total shoulder arthroplasty that had a deviation in the components predicted in the preoperative plan compared to patients that did not have a change in the components predicted in the preoperative plan. A retrospective review of patients that had preoperative planning for anatomic total shoulder arthroplasty from March 2017 thru October 2022 was performed. Patients were stratified into two groups: patients in which the surgeon utilized components that deviated from those anticipated by the preoperative plan (changed group), and patients in which the surgeon utilized all of the components anticipated by the preoperative plan (planned group). Patient-determined outcomes including the Western Ontario Osteoarthritis Index (WOOS), American Shoulder and Elbow Surgeons Score (ASES), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test (SST), and Shoulder Activity Level (SAL) were recorded preoperatively, at one-year, and at two-years. Preoperative and one-year postoperative range-of-motion was recorded. Radiographic parameters to assess restoration of proximal humeral anatomy included humeral head height, humeral neck angle, humeral centering on the glenoid, and postoperative restoration of the anatomic center of rotation. One-hundred-and-fifty-nine patients had intraoperative changes to their preoperative plan and 136 patients underwent arthroplasty without changes to their preoperative plan. The planned group had higher scores compared to the group that had a deviation in the preoperative plan for every patient-determined outcome metric at every postoperative timepoint with statistically significant improvements found in the SST and SANE at one-year and SST and ASES at two-year follow-up. No differences were found in range of motion metrics between groups. Patients that did not have a deviation in their preoperative plan had more optimal restoration of their postoperative radiographic center of rotation compared to patients that did have a deviation in their preoperative plan. Patients that have intraoperative changes to their preoperative plan have 1) inferior postoperative patient determined outcome scores at one and two years after surgery and 2) a larger deviation in the postoperative radiographic restoration of the humeral center of rotation compared to patients that did not have intraoperative changes from the initial plan.