High-Grade Partial Thickness Rotator Cuff Tears
Strong evidence supports the use of either conversion to full-thickness or transtendinous/in-situ repair in patients that failed conservative management with high-grade partial thickness rotator cuff tears.

There were two high quality study (Kim Y-S et al. 2015, and Shin et al. 2012) and two moderate quality studies (Castagna et al., Franceschi et al.).  The remainder of published studies either had too few subjects (<20) or were low quality level IV studies.  Kim Y-S et al. in a level II study noted no difference in either clinical outcomes or re-tear rates comparing transtendinous versus tear completion in Ellman III partial thickness rotator cuff tears.  Bursal side cuff tears had a higher re-tear rate with either technique.  Shin et al. in a level II study noted similar outcomes for the two groups but noted a significantly faster recovery with tear completion.  Retears were higher in the tear completion group but did not reach statistical significance. Castagna et al. looked at a total of 74 patients randomized to transtendinous versus tear completion.  There were no significant differences between the two groups.  Franceschi et al. in a level II study felt that outcomes and re-tear rates were comparable between transtendinous repair and tear completion.

Risks and Harms of Implementing this Recommendation

Future Research
Additional high quality level one studies with longer follow-up would be useful to establish if the results of these techniques hold up with time. Larger studies might also establish risk of retear with differing techniques.