Stemless, short and standard humeral stems in total shoulder arthroplasty: is there a difference in intraoperative measures, pain, and outcomes in the short term?

Abstract

BackgroundAs anatomic total shoulder arthroplasty (aTSA) has evolved, surgeons are utilizing stemless and short-stem humeral implants with increasing frequency. Bone preservation, decreased blood loss, decreased surgical time, decreased pain, and improved outcomes have been described as theoretical advantages for shorter stem and stemless implants. Comparisons of outcomes between different length humeral stems that control for manufacturer and model of humeral and glenoid implants are currently limited. The purpose of this study is to determine if differences exist in the short-term outcomes between stemless, short-stem (SS), and traditional-length (TL) humeral stems in aTSA. MethodsA multicenter international shoulder arthroplasty database utilizing a single implant system was retrospectively analyzed to compare intraoperative and short-term outcomes between stemless, SS, and TL humeral stem implants. Intraoperative measures including surgical time and estimated blood loss were recorded. Postoperative outcomes including improvements in multiple pain measures, Global Shoulder Function Score, Simple Shoulder Test, University of California at Los Angeles, American Shoulder and Elbow Surgeons, and Shoulder Pain and Disability Index scores were compared between the three cohorts at 0-3 months, 3-6 months, 6-12 months, and 1-2 years postoperatively. Statistical analysis was performed using a Student’s unpaired two-tailed t-test to quantify differences in means between cohorts with a P value < .05. Results203 stemless aTSAs were compared with 354 SS and 1159 TL aTSAs. Surgical time showed no difference between stemless (avg 89 min), SS (avg 94 min), and TL (avg 91 min) humeral component use (P > .05). Estimated blood loss was significantly higher in TL (avg 214 cc) when compared to SS (avg 165 cc, P < .001) and stemless (avg 180 cc, P < .001), with no significant difference between SS and stemless (P > .05). No differences were observed in improvement in postoperative pain between any cohort across all pain metrics recorded during the first 3 months postoperatively. Additionally, the stemless aTSA cohort did not show any significantly greater improvement in pain metrics at any time point postoperatively when compared to SS and TL cohorts. When evaluating improvements in global shoulder function, American Shoulder and Elbow Surgeons, Simple Shoulder Test, Constant, University of California at Los Angeles, and Shoulder Pain and Disability Index scores, the stemless cohort did not provide a significant advantage in outcome when compared to the SS and TL cohorts at 6-12 or 12-24 months. Discussion and ConclusionWhile stemless aTSA design provides distinct advantages in select patient populations, the proposed benefit of decreased pain and accelerated postoperative recovery following stemless aTSA are not substantiated by this study. The authors hope this study will aid surgeons in counseling prospective TSA patients in the risks and benefits of stem length selection in total shoulder replacement.