JSES - 2026-04-01 - Journal Article
Age influences lesser tuberosity osteotomy nonunion following anatomic total shoulder arthroplasty.
Lazaro JS, Nanavati R, Pignataro J, Austin LS, DeBernardis D
Topics
Key Takeaway
LTO nonunion occurred in 33.4% of aTSA patients, with younger age as the only significant predictor (OR 0.98 per year, p=0.037), yet only 2.7% of nonunions required revision surgery.
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Summary
This study examined patient- and technique-specific factors influencing LTO union after aTSA in 449 patients. Union was classified radiographically as healed (66.6%), nondisplaced nonunion (26.7%), or displaced nonunion (6.7%). Younger age was the sole significant predictor of nonunion (OR 0.98/year, p=0.037); implant type, LTO thickness, humeral head center of rotation change, and other demographics were non-significant.
Key Limitation
Minimum 3-month radiographic follow-up without a standardized endpoint means many 'nonunions' may represent delayed unions, artificially elevating the nonunion rate.
Original Abstract
BACKGROUND
Lesser tuberosity osteotomy (LTO) is one method that can be used for subscapularis mobilization during anatomic total shoulder arthroplasty (aTSA) and has reported union rates of 83%-97%. However, LTO nonunion remains a cause of aTSA failure, and the factors influencing LTO healing are not well understood. The goal of this study is to identify patient-specific and technique-specific factors affecting the incidence of LTO union following aTSA.
METHODS
We conducted a retrospective review of all patients who underwent aTSA with LTO between February 2019 and December 2021. Patients with at least 3 months of radiographic follow-up were included. LTO union was assessed using radiographs and classified as healed, nondisplaced nonunion, or displaced nonunion (DN). Patients who underwent revision surgery for LTO failure prior to the 3-month time point were categorized in the DN group. Patient demographics, surgical characteristics, and radiographic variables were analyzed to determine their influence on radiographic union.
RESULTS
Of the 449 included patients, 66.6% achieved LTO union, 26.7% were nondisplaced nonunion, and 6.7% were DN. Younger age was identified as a predictor of nonunion (odds ratio = 0.98; P = .037). No significant differences in union rates were observed based on implant type or size, LTO thickness, change in the humeral head center of rotation, or any additional demographic variables. Despite a 33.4% nonunion rate, only 2.7% of patients with nonunion required revision surgery due to subscapularis-related complications.
DISCUSSION
Younger age is a positive predictor of radiographic LTO nonunion following aTSA, while additional demographic, surgical, and radiographic factors do not significantly influence union rates. Despite the reported radiographic nonunion rate, the need for revision surgery remains low.