Subscapularis sparing total shoulder arthroplasty through a superolateral approach: a radiographic study

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiology

Background:

• Anatomic total shoulder arthroplasty (ATSA) often involves subscapularis tendon manipulation, risking healing complications.
• The deltopectoral (DP) approach is traditional, while the superolateral subscapularis sparing (SSS) technique offers an alternative through the rotator interval.

Purpose of the Study:

• To radiographically compare the outcomes of the traditional DP approach versus the SSS technique in ATSA.
• To evaluate key radiographic parameters and overall reconstruction quality between the two surgical methods.

Main Methods:

• A blinded reviewer analyzed preoperative and postoperative radiographs from patients undergoing ATSA via DP or SSS approaches.
• Measurements included humeral head height, offset, diameter, head-neck angle, centering, coracohumeral offset, and the anatomic reconstruction index (ARI).

Main Results:

• No significant differences were found in humeral head height, medial offset, or coracohumeral offset between the DP and SSS groups.
• The DP group showed humeral head oversizing (1.4 mm), while the SSS group had undersizing (2.8 mm) (P < .001).
• The SSS group had a greater head-neck angle difference (2°) and poorer humeral head centering (12% vs. 7%) compared to the DP group (P < .001).

Conclusions:

• The SSS ATSA technique demonstrates no statistically significant difference in 4 of 7 radiographic measurements and the ARI compared to the traditional DP approach.
• The SSS approach is a reasonable alternative to the DP approach for ATSA, yielding similar radiographic results.