Multicenter prospective study of 128 shoulders with primary osteoarthritis treated by total shoulder arthroplasty or hemiarthroplasty. It asks which preoperative anatomic factors predict outcome: glenoid erosion, humeral head subluxation, stiffness, and rotator cuff tears. Follow-up averaged 46 months.
The practical decision rule: when the glenoid is eccentrically worn posteriorly, resurface it. Total shoulder arthroplasty gave meaningfully better rotation and flexion than hemiarthroplasty in these shoulders, and the authors attribute this to restoring a concentric fulcrum after reaming out retroversion.
Read the preoperative axillary view carefully. Grade glenoid bone loss (mild <5 mm, moderate 5-10 mm, severe >10 mm) and check for posterior head subluxation (>25% of head diameter off-center). Subluxation is a red flag. It marks the most advanced disease and predicts worse pain and function regardless of implant choice, so counsel these patients accordingly.
Two myths are addressed. A small repairable supraspinatus tear does not bar a glenoid component, and a very stiff shoulder (passive ER <10°) argues for total shoulder arthroplasty with soft-tissue release rather than hemiarthroplasty. Operate before stiffness becomes fixed.
Multicenter prospective study of 128 shoulders with primary osteoarthritis treated by total shoulder arthroplasty or hemiarthroplasty. It asks which preoperative anatomic factors predict outcome: glenoid erosion, humeral head subluxation, stiffness, and rotator cuff tears. Follow-up averaged 46 months.
The practical decision rule: when the glenoid is eccentrically worn posteriorly, resurface it. Total shoulder arthroplasty gave meaningfully better rotation and flexion than hemiarthroplasty in these shoulders, and the authors attribute this to restoring a concentric fulcrum after reaming out retroversion.
Read the preoperative axillary view carefully. Grade glenoid bone loss (mild <5 mm, moderate 5-10 mm, severe >10 mm) and check for posterior head subluxation (>25% of head diameter off-center). Subluxation is a red flag. It marks the most advanced disease and predicts worse pain and function regardless of implant choice, so counsel these patients accordingly.
Two myths are addressed. A small repairable supraspinatus tear does not bar a glenoid component, and a very stiff shoulder (passive ER <10°) argues for total shoulder arthroplasty with soft-tissue release rather than hemiarthroplasty. Operate before stiffness becomes fixed.