Subscapularis Muscle Function and Structure After Total Shoulder Replacement With Lesser Tuberosity Osteotomy and Repair

Subscapularis Release in Shoulder Replacement Determines Structural Muscular Changes

“…Gerber et al [12], Ponce et al [29], and Scalise et al [35] advised a thickness of the osteotomized lesser tuberosity between 5 mm and 10 mm and a length between 3 cm and 4 cm. To create this osteotomy, a saw, drill, or chisel traditionally is used directed parallel to the subscapularis tendon.…”

“…This technique appears technically easy in creating a consistent bony fragment. Another technical specificity of our osteotomy is reattachment of the lesser tuberosity with cerclage wires instead of a tension band [12,35]. According to Frankle et al [8], interfragmentary motion and strain theoretically are decreased, fragment stability is maximized, and postoperative rehabilitation facilitated.…”

“…improve subscapularis tendon healing, some authors advocate an osteotomy of the lesser tuberosity as bone-tobone healing is more reliable than tendon-to-bone [12,31]. Osteotomy of the lesser tuberosity reportedly is associated with a lower rate of subscapularis tendon tears after total shoulder arthroplasty when compared with subscapularis tenotomy [29,35], and consequently with superior subscapularis function [29].…”

“…Despite more reliable subscapularis tendon reattachment, degeneration of the subscapularis muscle after open surgical release remains a concern [12,20,26,29,36]: fatty infiltration of the subscapularis muscle progresses by at least one stage in 45% of cases postoperatively [12]. Fatty muscular degeneration negatively influences strength, mobility, and overall Constant-Murley scores [7,12].…”

“…Fatty muscular degeneration negatively influences strength, mobility, and overall Constant-Murley scores [7,12]. The reason for progression of fatty infiltration of the subscapularis muscle is unknown, but denervation during surgical approach has been suggested [26].…”