Single-Row vs Double-Row Repair
Strong evidence does not support double row rotator cuff repair constructs on improving patient-reported outcomes compared to single row vertical mattress repair constructs.

Rationale
Nine high quality randomized controlled trials (RCTs) comparing single row versus double row constructs for full thickness rotator cuff tears reported significant improvement in all patient reported outcomes (PROs) at final follow-up; however, there were no clinically meaningful difference in PROs between the two repair groups (Aydin 2010, Barber 2016, Burks, 2009, Franceschi 2016, Franceschi 2007, Koh 2011, Lapner 2012, Ma 2012, Carbonel 2012). Two high quality RCTs reported significant improvement in PROs (UCLA scores, ASES scores, or strength testing) favoring double row repair in patients with >3cm full thickness rotator cuff tears (Ma 2012, Carbonel 2012) Aydin et al reported no difference in the Constant scores or complication rates between the two groups of single row (N=34) and double row (N=34) repair at final follow-up.  Barber et al also reported no difference in all PROs between single row (N=20) compared to double row (N=20) repair for full thickness cuff tears less than 3cm augmented with platelet-rich plasma fibrin membrane.  The failure rate at final follow-up was also similar between both groups, 3 out of 20 (15%) in each group.  Furthermore, Burks et al, Franceschi et al, , Koh et al, and Lapner et al also found no clinically meaningful difference in the PROs between single row and double row repair for full thickness rotator cuff tears at final follow-up.  Ma et al also reported similar UCLA and ASES scores at final follow-up comparing single to double row repair. However, in the subset of patients with >3cm full thickness tears, the authors reported significantly better shoulder strength in abduction and external rotation with double row repair at final follow-up.  In the largest RCT comparing the outcome of single row versus double row repair, Carbonel et al reported similar PROs in patients with 1cm to 3cm tears. However, in patients with >3cm tears, double row repair showed superior results in both UCLA and ASES scores compared to single row repair.

Risks and Harms of Implementing this Recommendation
There is no harm to patients by implementing this recommendation for small to medium size rotator cuff tears.  However, in patients with larger rotator cuff tears (>3cm), single row vertical mattress repair may result in inferior PROs and higher failure rates compared to double row repair constructs.

Future Research
Future research needs to be performed to evaluate for both PROs and failure rates on imaging and reoperation rates between single row compared to double row repair for larger full thickness rotator cuff tears >3cm in size.