Background: Rotator cuff tears often cause shoulder pain and functional limitations that may require conservative treatment or surgical intervention. Identifying preoperative differences in muscle strength and function can aid in treatment decisions. Objects: This study aimed to compare the preoperative shoulder muscle strength and functional outcomes between patients undergoing arthroscopic rotator cuff repair and those receiving conservative treatment. Methods: A retrospective review was conducted of 315 patients with rotator cuff tears, including 145 who underwent surgery and 170 who received conservative treatment. Shoulder isokinetic muscle strength (external rotator, internal rotators, abductor, and adductors) and functional scores (American Shoulder and Elbow Surgeons [ASES] and Constant-Murley shoulder scores) were measured. The conservative treatment group was assessed during a hospital visit, whereas the surgery group was tested on the morning of the surgery. An independent t-test was used to evaluate the preoperative shoulder strength and functional scores. Results: The conservative treatment group showed lower deficits in external (11.3 ± 23.9) and internal (11.7 ± 15.5) rotators compared to the surgery group (26.3 ± 33.8 and 17.1 ± 26.1, respectively; p = 0.001). Abductor and adductor deficits (18.2 ± 25.3 and 9.8 ± 16.8) were also lower in the conservative treatment group (30.7 ± 31.6 and 21.9 ± 28.4, respectively; p = 0.036 and p = 0.001). The external per internal rotator ratio (50.9 ± 16.8; p = 0.003) and ASES scores were higher (74.5 ± 14.8; p = 0.047) was higher in the conservative treatment group. Conclusion: The conservative treatment group had lower shoulder strength deficits, better muscle balance, and higher ASES scores than the surgery group, indicating superior functional outcomes. These findings suggest that assessing preoperative muscle strength and function might provide valuable insights into treatment planning for patients with rotator cuff tears.

INTRODUCTION
MATERIALS AND METHODS
    1. Patients
    2. Outcome
    3. Procedure
    4. Statistical Analysis
RESULTS
DISCUSSION
CONCLUSIONS
FUNDING
CONFLICTS OF INTEREST
AUTHOR CONTRIBUTION
ORCID
REFERENCES

• Jin-seong Kim(Department of Physical Therapy, Ilsan Paik Hospital, College of Medicine, Inje University, Goyang)
• Ui-jae Hwang(Department of Physical Therapy, College of Software and Digital Healthcare Convergence, Yonsei University)
• Il-kyu Ahn(Department of Physical Therapy, The Graduate School, Yonsei University, Kinetic Ergocise Based on Movement Analysis Laboratory, Wonju, Korea)
• Oh-yun Kwon(Department of Physical Therapy, College of Software and Digital Healthcare Convergence, Yonsei University, Department of Physical Therapy, The Graduate School, Yonsei University, Kinetic Ergocise Based on Movement Analysis Laboratory, Wonju, Korea) Corresponding author