Evaluation of the Effect of Intra-Articular Hyaluronic Acid Injection on Postoperative Stiffness in Patients with Distal Radius Fractures Treated with Volar Plate Fixation (ORIF): A Randomized Clinical Trial

To determine the effect of a single intra-articular injection of Hyaluronic Acid on wrist range of motion at 12 weeks postoperatively in patients undergoing volar plate fixation for distal radius fracture

This study is a randomized, controlled, parallel-group clinical trial with a two-arm design and blinded outcome assessment. It is conducted as a phase II trial including 60 patients. Randomization is performed using block randomization with a 1:1 allocation ratio

This is a randomized, parallel, double-blind clinical trial conducted at Imam Khomeini Hospital, Tehran. Adult patients (18–70 years) undergoing ORIF for distal radius fractures are allocated into two groups using block randomization with sealed opaque envelopes. The intervention group receives a single 2-mL intra-articular hyaluronic acid injection at the end of surgery; the control group receives no injection. Both patients and outcome assessors are blinded. Outcomes (ROM, pain, and function) are assessed at weeks 2, 6, and 12

Inclusion: Adult patients with acute, closed distal radius fractures requiring volar plate fixation Exclusion: Conditions that may interfere with the intervention, safety, or study follow-up

Intervention Group (HA): Patients receive a single 2-mL intra-articular injection of hyaluronic acid (20 mg sodium hyaluronate in 2 mL) after completion of surgery and wound closure. Control Group: Patients do not receive any intra-articular injection and are managed with standard postoperative care following ORIF.

Primary outcome: Wrist range of motion (ROM) at week 12. Secondary outcomes: Pain (VAS) at weeks 2, 6, 12; wrist function (Quick-DASH) at weeks 6, 12; postoperative complications (stiffness, swelling, infection) up to week 12.

Eligible patients, after providing informed consent, are randomly assigned to the intervention or control groups using block randomization with a 1:1 allocation ratio. The unit of randomization is the individual patient, and no stratified randomization is applied. The random sequence is generated using statistical software based on blocks of variable size to minimize predictability of group assignment. Allocation concealment is ensured by using sequentially numbered, opaque, sealed envelopes containing the group allocation codes, which are opened only after completion of surgery and wound closure, thereby minimizing selection bias.

In this study, participants (patients) are blinded to their group allocation. Outcome assessors, including physiotherapists and personnel responsible for measuring range of motion, pain scores, and functional outcomes, are blinded to group assignment. The statistical analyst performs data analysis using anonymized group codes and is not aware of the treatment allocation. Due to the nature of the intervention, the operating surgeon is aware of the group assignment at the time of intervention; however, the surgeon has no role in outcome assessment, data collection, or statistical analysis. All participants are fully informed about their participation in the study, and written informed consent is obtained; lack of patient awareness of study participation is not involved.

Title of shared documents: De-identified raw dataset of primary and secondary outcome measures. Details: Individual participant data will be shared only after complete removal of all identifiable information (including names, national identification numbers, and hospital record numbers). The shared dataset will include wrist range-of-motion measurements, pain scores, functional questionnaire results, and postoperative complication records. Data will be provided exclusively in a fully de-identified format and only for research purposes, upon formal request and approval by the ethics committee

Access to the shared dataset will begin six months after publication of the final study results and will remain available for at least three years thereafter

Requests for access to the study data may be submitted only by researchers and academic investigators affiliated with recognized universities or research institutions. Applicants must present a clearly defined scientific purpose and obtain ethics committee approval. Data will not be shared with individuals or organizations seeking access for commercial or industrial purposes

Access to de-identified data will be granted only if the applicant provides a defined research proposal, clear scientific objectives, and an appropriate analysis plan. Use of the data is restricted to academic and statistical research purposes only. Commercial use, promotional use, or redistribution of the dataset is strictly prohibited. Applicants must sign a confidentiality agreement and are permitted to use the dataset solely within the scope of the ethics-approved research protocol. Further sharing of the dataset with third parties without written permission is not allowed

Applicants who wish to obtain the study data or related documentation may submit their official request primarily via email, followed by telephone contact if needed. The designated contact person for responding to data requests is Dr. Ebrahim Khazaee. Email addresses for correspondence: E-khazaee@student.tums.ac.ir khazaei70@yahoo.com Telephone number: +989156210690 If in-person or postal correspondence becomes necessary, arrangements will be made through the above email addresses and the postal address will be provided accordingly. Applicants must submit a clear research objective and a relevant study proposal along with their request

The process for obtaining the requested dataset consists of several steps. Applicants must first submit an official request via email, including their research objective and study proposal. The request will be reviewed within 7–14 business days, and additional clarification may be requested if needed. Following initial approval, the request will be evaluated for ethical compliance, which typically requires 14–30 business days. After final approval, the de-identified dataset will be provided within 14 business days through a secure email or restricted access link. Overall, the estimated time required to receive the dataset ranges from 4 to 8 weeks, depending on administrative processing time and applicant responsiveness