Restoration of external (ER) and internal rotation (IR) after Grammont-style reverse shoulder arthroplasty (RSA) is often unreliable. The purpose of this systematic review was to evaluate the influence of RSA medio-lateral offset and subscapularis repair on axial rotation after RSA. Methods: We conducted a systematic review of studies evaluating axial rotation (ER, IR, or both) after RSA with a defined implant design. Medio-lateral implant classification was adopted from Werthel et al. Meta-analysis was conducted using a random-effects model. Results: Thirty-two studies reporting 2,233 RSAs were included (mean patient age, 72.5 years; follow-up, 43 months; 64% female). The subscapularis was repaired in 91% (n=2,032) of shoulders and did not differ based on global implant lateralization (91% for both, P=0.602). On meta-analysis, globally lateralized implants achieved greater postoperative ER (40° [36°–44°] vs. 27° [22°–32°], P<0.001) and postoperative improvement in ER (20° [15°–26°] vs. 10° [5°–15°], P<0.001). Lateralized implants with subscapularis repair or medialized implants without subscapularis repair had significantly greater postoperative ER and postoperative improvement in ER compared to globally medialized implants with subscapularis repair (P<0.001 for both). Mean postoperative IR was reported in 56% (n=18) of studies and achieved the minimum necessary IR in 51% of lateralized (n=325, 5 cohorts) versus 36% (n=177, 5 cohorts) of medialized implants. Conclusions: Lateralized RSA produces superior axial rotation compared to medialized RSA. Lateralized RSA with subscapularis repair and medialized RSA without subscapularis repair provide greater axial rotation compared to medialized RSA with subscapularis repair. Level of evidence: 2A.

Background: To compare clinical outcomes following lateralized reverse shoulder arthroplasty (RSA) versus RSA with latissimus dorsi transfer (LDT) in patients with poor preoperative active external rotation (ER). Methods: We performed a systematic review per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We queried PubMed/Medline, Embase, Web of Science, and Cochrane databases to identify articles reporting clinical outcomes of RSA with LDT or lateralized RSA alone performed in patients with preoperative ER ≤0°. Our primary outcomes were active ER, active forward elevation (FE), Constant score, and the incidence of complications. Results: We included 12 RSA with LDT studies with 188 shoulders and 4 lateralized RSA without transfer studies with 250 shoulders. Mean preoperative ER in RSA with LDT was –14°, while mean preoperative ER in lateralized RSA alone was –11°. Lateralized RSA alone was associated with superior postoperative ER (28° vs. 22°, P=0.010) and Constant score (69 vs. 65, P=0.014), but similar postoperative FE (P=0.590). Pre- to postoperative improvement in ER and FE was similar between cohorts. RSA with LDT had a higher incidence of nerve-related complications (2.1% vs. 0%) and dislocation (2.8% vs. 0.8%) compared to lateralized RSA alone. Conclusions Both RSA with LDT and lateralized RSA are reliable options to restore ER in patients with significantly limited preoperative ER. Our analysis suggests that lateralized RSA alone is superior to RSA with LDT in patients with either a medialized or lateralized implant design and confers a lower risk of complications, particularly nerve injury and dislocation. However, the addition of an LDT may still be indicated in certain patient populations with very severe ER loss.Level of evidence: IV.

Background: To compare clinical outcomes following lateralized reverse shoulder arthroplasty (RSA) versus RSA with latissimus dorsi transfer (LDT) in patients with poor preoperative active external rotation (ER). Methods: We performed a systematic review per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We queried PubMed/Medline, Embase, Web of Science, and Cochrane databases to identify articles reporting clinical outcomes of RSA with LDT or lateralized RSA alone performed in patients with preoperative ER ≤0°. Our primary outcomes were active ER, active forward elevation (FE), Constant score, and the incidence of complications. Results: We included 12 RSA with LDT studies with 188 shoulders and 4 lateralized RSA without transfer studies with 250 shoulders. Mean preoperative ER in RSA with LDT was –14°, while mean preoperative ER in lateralized RSA alone was –11°. Lateralized RSA alone was associated with superior postoperative ER (28° vs. 22°, P=0.010) and Constant score (69 vs. 65, P=0.014), but similar postoperative FE (P=0.590). Pre- to postoperative improvement in ER and FE was similar between cohorts. RSA with LDT had a higher incidence of nerve-related complications (2.1% vs. 0%) and dislocation (2.8% vs. 0.8%) compared to lateralized RSA alone. Conclusions Both RSA with LDT and lateralized RSA are reliable options to restore ER in patients with significantly limited preoperative ER. Our analysis suggests that lateralized RSA alone is superior to RSA with LDT in patients with either a medialized or lateralized implant design and confers a lower risk of complications, particularly nerve injury and dislocation. However, the addition of an LDT may still be indicated in certain patient populations with very severe ER loss.Level of evidence: IV.

Background: To compare clinical outcomes following lateralized reverse shoulder arthroplasty (RSA) versus RSA with latissimus dorsi transfer (LDT) in patients with poor preoperative active external rotation (ER). Methods: We performed a systematic review per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We queried PubMed/Medline, Embase, Web of Science, and Cochrane databases to identify articles reporting clinical outcomes of RSA with LDT or lateralized RSA alone performed in patients with preoperative ER ≤0°. Our primary outcomes were active ER, active forward elevation (FE), Constant score, and the incidence of complications. Results: We included 12 RSA with LDT studies with 188 shoulders and 4 lateralized RSA without transfer studies with 250 shoulders. Mean preoperative ER in RSA with LDT was –14°, while mean preoperative ER in lateralized RSA alone was –11°. Lateralized RSA alone was associated with superior postoperative ER (28° vs. 22°, P=0.010) and Constant score (69 vs. 65, P=0.014), but similar postoperative FE (P=0.590). Pre- to postoperative improvement in ER and FE was similar between cohorts. RSA with LDT had a higher incidence of nerve-related complications (2.1% vs. 0%) and dislocation (2.8% vs. 0.8%) compared to lateralized RSA alone. Conclusions Both RSA with LDT and lateralized RSA are reliable options to restore ER in patients with significantly limited preoperative ER. Our analysis suggests that lateralized RSA alone is superior to RSA with LDT in patients with either a medialized or lateralized implant design and confers a lower risk of complications, particularly nerve injury and dislocation. However, the addition of an LDT may still be indicated in certain patient populations with very severe ER loss.Level of evidence: IV.

Background: To compare clinical outcomes following lateralized reverse shoulder arthroplasty (RSA) versus RSA with latissimus dorsi transfer (LDT) in patients with poor preoperative active external rotation (ER). Methods: We performed a systematic review per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We queried PubMed/Medline, Embase, Web of Science, and Cochrane databases to identify articles reporting clinical outcomes of RSA with LDT or lateralized RSA alone performed in patients with preoperative ER ≤0°. Our primary outcomes were active ER, active forward elevation (FE), Constant score, and the incidence of complications. Results: We included 12 RSA with LDT studies with 188 shoulders and 4 lateralized RSA without transfer studies with 250 shoulders. Mean preoperative ER in RSA with LDT was –14°, while mean preoperative ER in lateralized RSA alone was –11°. Lateralized RSA alone was associated with superior postoperative ER (28° vs. 22°, P=0.010) and Constant score (69 vs. 65, P=0.014), but similar postoperative FE (P=0.590). Pre- to postoperative improvement in ER and FE was similar between cohorts. RSA with LDT had a higher incidence of nerve-related complications (2.1% vs. 0%) and dislocation (2.8% vs. 0.8%) compared to lateralized RSA alone. Conclusions Both RSA with LDT and lateralized RSA are reliable options to restore ER in patients with significantly limited preoperative ER. Our analysis suggests that lateralized RSA alone is superior to RSA with LDT in patients with either a medialized or lateralized implant design and confers a lower risk of complications, particularly nerve injury and dislocation. However, the addition of an LDT may still be indicated in certain patient populations with very severe ER loss.Level of evidence: IV.