87 patients undergoing shoulder arthroplasty were randomized to receive lesser tuberosity osteotomy (LTO) or subscapularis tenotomy (ST) to compare differences in healing rates and fatty infiltration. At 12 months, there was no difference between the two groups with respect to the healing rate and the Goutallier mean fatty infiltration grade. From the pre-operative assessment to the post-operative evaluation, there was a one-grade increase in fatty infiltration in the ST group, whereas there was a 0.5 grade increase in the LTO group. Assessment following the 12 month follow-up failed to identify a superior technique for subscapularis mobilization.