Subscapularis-Sparing Total Shoulder Arthroplasty

Subscapularis-Sparing Total Shoulder Arthroplasty: A Prospective Study

The investigators purpose of this study are to perform a prospective clinical study to determine the following after subscapularis-sparing anatomic total shoulder arthroplasty performed for glenohumeral osteoarthritis:

1. patient-reported outcomes
2. shoulder motion and strength
3. rotator cuff integrity
4. the accuracy of component placement and the completeness of osteophyte removal

Study Overview

• Status: Enrolling by invitation
• Conditions: Total Shoulder Arthroplasty
• Intervention / Treatment: Procedure: Subscapularis-Sparing Total Shoulder Arthroplasty

Detailed Description

Anatomic total shoulder arthroplasty (TSA) provides excellent pain relief and restoration of shoulder function in the setting of glenohumeral osteoarthritis. However, the surgical approach requires the subscapularis to be cut and repaired, via either a lesser tuberosity osteotomy, a subscapularis tenotomy, or a subscapularis peel.This repair must be protected post-operatively, even with a lesser tuberosity osteotomy, or it can displace or fail to heal, which complicates rehabilitation. Failure of the subscapularis repair occurs in 10-25% of patients. Failure of the subscapularis repair is often devastating for shoulder function and often requires revision to a reverse total shoulder arthroplasty. Even when muscle-tendon-bone healing does occur there is post-operative atrophy of the subscapularis that may compromise function and strength. Atrophy of the subscapularis may lead to imbalance of the rotator cuff musculature, leading to subluxation and glenoid loosening. While there have been attempts to develop approaches that do not involve cutting the subscapularis, they have been plagued by osteophyte retention, component malposition, damage to the deltoid, or damage to the supraspinatus.

The principal investigator has spent four years developing a technique for anatomic total shoulder arthroplasty that does not involve cutting any muscles or tendons and has been through the learning curve with this technique by completing >20 cases and at least as many cadaver surgeries during that time period. This technique has been designed to avoid the potential issues with prior attempts and utilizes purpose designed instrumentation and retractors.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

Study Locations

• United States
  • Utah
    • Salt Lake City, Utah, United States, 84108
      • University of Utah Orthopedics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing subscapularis-sparing anatomic total shoulder arthroplasty.

Description

Inclusion Criteria:

• Patients undergoing subscapularis-sparing anatomic total shoulder arthroplasty by the principal investigator at the University of Utah.

Exclusion Criteria:

• Patients unwilling to consent and comply with study procedures (i.e. follow up visits).
• Patients under the age of 18.
• Patients with contraindications to an anatomic total shoulder arthroplasty such as active infection, insufficient glenoid bone, damage to the rotator cuff, or a history of instability.
• Patients with known prior shoulder arthroplasty.
• Patients unable to undergo a magnetic resonance imaging study.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient-reported outcome (American Shoulder and Elbow Surgeons (ASES) Score	Shoulder specific scoring system out of 100. A patient-reported score with visual analog scale for pain and functional subscales ranging from 0 (worse pain and function loss) to 50 (no pain and excellent function). Both scores are summed for a maximum score of 100.	Pre-operative
Patient-reported outcome (Simple Shoulder Test (SST))	There are 12 shoulder specific questions which the patient answers "yes" or "no". The questions ask about strength, function and range of motion. To score the test, divide the number of "yes" answers by the total number of questions answered and then multiply by 100. 0% is the worst score to 100% being the best score.	Pre-operative
Patient-reported outcome (Visual Analogue Score (VAS))	VAS pain score (0 no pain - 10 severe pain)	Pre-operative
Patient-reported outcome (American Shoulder and Elbow Surgeons (ASES) Score	Shoulder specific scoring system out of 100. A patient-reported score with visual analog scale for pain and functional subscales ranging from 0 (worse pain and function loss) to 50 (no pain and excellent function). Both scores are summed for a maximum score of 100.	6-weeks post-operative
Patient-reported outcome (Simple Shoulder Test (SST))	There are 12 shoulder specific questions which the patient answers "yes" or "no". The questions ask about strength, function and range of motion. To score the test, divide the number of "yes" answers by the total number of questions answered and then multiply by 100. 0% is the worst score to 100% being the best score.	6-weeks post-operative
Patient-reported outcome (Visual Analogue Score (VAS))	VAS pain score (0 no pain - 10 severe pain)	6-weeks post-operative
Patient-reported outcome (American Shoulder and Elbow Surgeons (ASES) Score	Shoulder specific scoring system out of 100. A patient-reported score with visual analog scale for pain and functional subscales ranging from 0 (worse pain and function loss) to 50 (no pain and excellent function). Both scores are summed for a maximum score of 100.	3-months post-operative
Patient-reported outcome (Simple Shoulder Test (SST))	There are 12 shoulder specific questions which the patient answers "yes" or "no". The questions ask about strength, function and range of motion. To score the test, divide the number of "yes" answers by the total number of questions answered and then multiply by 100. 0% is the worst score to 100% being the best score.	3-months post-operative
Patient-reported outcome (Visual Analogue Score (VAS))	VAS pain score (0 no pain - 10 severe pain)	3-months post-operative
Patient-reported outcome (American Shoulder and Elbow Surgeons (ASES) Score	Shoulder specific scoring system out of 100. A patient-reported score with visual analog scale for pain and functional subscales ranging from 0 (worse pain and function loss) to 50 (no pain and excellent function). Both scores are summed for a maximum score of 100.	1-year post-operative
Patient-reported outcome (Simple Shoulder Test (SST))	There are 12 shoulder specific questions which the patient answers "yes" or "no". The questions ask about strength, function and range of motion. To score the test, divide the number of "yes" answers by the total number of questions answered and then multiply by 100. 0% is the worst score to 100% being the best score.	1-year post-operative
Patient-reported outcome (Visual Analogue Score (VAS))	VAS pain score (0 no pain - 10 severe pain)	1-year post-operative
Patient-reported outcome (American Shoulder and Elbow Surgeons (ASES) Score	Shoulder specific scoring system out of 100. A patient-reported score with visual analog scale for pain and functional subscales ranging from 0 (worse pain and function loss) to 50 (no pain and excellent function). Both scores are summed for a maximum score of 100.	2-years post-operative
Patient-reported outcome (Simple Shoulder Test (SST))	There are 12 shoulder specific questions which the patient answers "yes" or "no". The questions ask about strength, function and range of motion. To score the test, divide the number of "yes" answers by the total number of questions answered and then multiply by 100. 0% is the worst score to 100% being the best score.	2-years post-operative
Patient-reported outcome (Visual Analogue Score (VAS))	VAS pain score (0 no pain - 10 severe pain)	2-years post-operative

Collaborators and Investigators

• Sponsor: University of Utah
• Investigators: Principal Investigator: Peter Chalmers, M.D., University of Utah Orthopaedics

Study record dates

Study Major Dates

• Study Start (Actual): January 29, 2021
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027

Study Registration Dates

• First Submitted: February 5, 2026
• First Submitted That Met QC Criteria: February 12, 2026
• First Posted (Actual): February 13, 2026

Study Record Updates

• Last Update Posted (Actual): February 13, 2026
• Last Update Submitted That Met QC Criteria: February 12, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Patient-Reported Outcomes; Total Shoulder Arthroplasty; Prospective Study; Glenohumeral Osteoarthritis; Subscapularis-Sparing
• Other Study ID Numbers: 137991

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No