The Effect of Ascorbic Acid (Vitamin C) on Functional Recovery and Pain relief Following Open Rotator Cuff Repair: A Randomized Clinical Tria

1.To provide scientific evidence regarding the impact of ascorbic acid supplementation on functional recovery in patients following rotator cuff repair surgery.

A parallel-group, double-blind, randomized clinical trial will be conducted on 64 patients using block randomization via the software available at randomizer.org

This study will be conducted at Firouzgar Hospital among patients diagnosed with full-thickness rotator cuff tears. Follow-up assessments will be performed using structured questionnaires and clinical examinations

Inclusion Criteria Patients aged 18 years and older undergoing open surgical repair for rotator cuff tears. Confirmation of full-thickness tear in one or more rotator cuff tendons based on preoperative MRI and intraoperative verification. Provision of written informed consent to participate in the study and commitment to scheduled postoperative follow-up. Adequate general health status to complete the standard postoperative treatment and rehabilitation process. Exclusion Criteria History of prior surgical intervention on the same shoulder Presence of neurological or muscular disorders that may affect shoulder functional outcomes . Significant concomitant injuries to other shoulder structures Pregnancy or presence of uncontrolled systemic conditions such as poorly managed diabetes mellitus or advanced renal failure.

In the intervention group, an oral vitamin C supplement at a daily dose of 500 mg will be administered starting from the first postoperative day and continued for six weeks. The selected brand is Nature Made®. The control group will receive a placebo for comparative evaluation

Upper limb function Pain intensity Range of motion of the shoulder joint

Patients will be randomly assigned to either the intervention or control group using block randomization implemented through specialized software. In block randomization, a predetermined number of patients (e.g., multiples of 4 or 6) are grouped into blocks, and the allocation sequence within each block is randomly generated to ensure balanced group sizes. This method helps maintain an approximately equal number of participants in both groups throughout the study.

To ensure a double-blind study design, the supplement and placebo were manufactured to be identical in appearance, taste, and packaging. Each product was labeled with a unique code rather than a name, and these codes were accessible only to the pharmacist or principal investigator. The codes remained concealed until the end of the study. Consequently, neither the patients nor the clinical team, evaluators, or statistical analysts were aware of the type of intervention administered.

Participant Data File Informed Consent Form

Access to the resources will commence at the end of the Iranian calendar year 1406, corresponding approximately to March 2028.

for all people

All individuals requesting to review the rotator cuff data are granted access to the dataset. Permission is hereby granted for the performance of all statistical analyses on the data. Furthermore, individuals are permitted to utilize this data in their own studies, provided that proper citation and reference is made to the original publication.

Iran University of Medical Sciences Research Department Adjacent to Milad Tower, Hemmat Highway Tehran, Iran Postal Code: 1449614535 Tel: (+98 21) 86701 Email: info@iums.ac.ir

Following correspondence with the Research Department of Iran University of Medical Sciences, access to the dataset will be granted within one business week.