Comparison of functional outcomes in Zone 1 flexor tendon injuries treated with classical transosseous versus paraosseous pull-out button techniques: A randomized, parallel-group, double-blinded (participant and outcome assessor) clinical trial

To critically evaluate and compare the functional outcomes, biomechanical efficacy, and complication rates of Zone 1 FDP tendon repairs utilizing two distinct pull-out button placement techniques: the classical bone-penetrating (transosseous) method versus the tissue-sparing (paraosseous) method.

A parallel-group, randomized, double-blind, actively controlled clinical trial comprising 50 participants.

The trial will be conducted at Shohadaye Ashayer Hospital, Khorramabad, Iran. Following strict inclusion, a SNOSE protocol will ensure allocation concealment. All surgical procedures will be standardized and performed by a single board-certified reconstructive subspecialist. The study enforces double-blinding protocols: patients are blinded to the allocated surgical technique, and all post-operative evaluations are recorded independently by a blinded plastic surgeon.

The target population comprises adults (18-60 years) presenting with acute (<72 hours) Zone 1 FDP tendon lacerations or avulsions (gap <1 cm) indicated for primary surgical repair. Exclusion criteria apply to patients with confounding musculoskeletal injuries (crush trauma, intra-articular fractures), systemic diseases impairing tissue healing, or existing sensory neuropathies.

Fifty eligible participants will be randomly allocated to either Group 1 (Classical Transosseous pull-out method, n=25) or Group 2 (Paraosseous paronychia-routed pull-out method, n=25).

Primary variables include patient-reported upper extremity disability (DASH score) and objective joint mobility (Modified Strickland Score). Secondary variables evaluate grip/pinch strength dynamometry, digital edema, pain severity (VAS), sensory recovery, and adverse events (nail dystrophies, infection, tendon re-rupture, adhesions).

Simple randomization will be executed using a computer-generated random number sequence. Allocation concealment will be strictly maintained using sequentially numbered, opaque, sealed envelopes (SNOSE). Envelopes will be opened by a non-surgical staff member in the operating room just prior to the intervention to reveal the designated technique (A: Classical transosseous, B: Paraosseous).

Due to the nature of the surgical intervention, the operating surgeon cannot be blinded. Therefore, this trial is double-blinded targeting the participants and the outcome assessors. Patients will be unaware of the specific button-placement technique used. Post-operative assessments (functional scoring, ROM, complications) will be conducted by an independent plastic surgeon who is entirely blinded to group allocation.

Data set title: “Individual Participant Data (IPD) for the trial comparing FDP tendon repair by transosseous versus paraosseous pull-out methods.” Data to be shared: All collected deidentified IPD underlying the results reported in the article, including primary and secondary outcome measures (VAS scores, chronic nail-bed pain, nail deformity, and range of motion/ROM), together with the data dictionary.

Timing and Duration of Data Availability The deidentified Individual Participant Data (IPD) and associated documentation for this study will become available six months after final publication of the manuscript in the target journal (expected in late 2026 or early 2027), through a reputable public repository (e.g., Figshare or Zenodo). Duration of availability: The data will be retained and accessible for a minimum of five years from the date of publication. Conditions of access: All applicants may request access by submitting a written request to the Principal Investigator and signing a Data Use Agreement, at no cost.

Description of Persons and Institutions Eligible to Receive Deidentified IPD and Supporting Information The deidentified Individual Participant Data (IPD) and accompanying supporting materials (including the data dictionary, analysis methodology, and statistical reports) will be made available to all researchers, scientists, and professionals in fields related to orthopedic surgery, hand surgery, microsurgery, and clinical sciences—regardless of whether they work in academic institutions, government agencies, industry, pharmaceutical companies, or medical technology firms. Conditions and Requirements for Access: Purpose of Use: Applicants must specify the intended purpose. Permitted uses include: academic research, medical product development, meta-analyses, health evaluations, and education. Data Use Agreement (DUA): All applicants must sign a DUA committing to use the data solely for approved purposes. Intellectual Property: The data remain the property of the original investigators. Applicants may not sell or redistribute the data. Ownership of Results: Results derived from the data belong to the requesting researcher, provided that the original investigators are acknowledged as collaborators or sources in any final publication. No Re-identification: Applicants must commit to not attempting to re-identify individuals from the deidentified dataset. Oversight: The original investigators retain oversight rights and may revoke access in case of violation. Notes: Commercial use is permitted, subject to the above terms. Uses that violate patient privacy or conflict with Iranian health and ethical regulations are prohibited.

Access Criteria and Data Sharing Mechanism Types of analyses permitted: Secondary analyses to address new research questions related to FDP tendon repair Meta-analyses and systematic reviews Validation studies and comparisons with similar datasets Predictive modeling or advanced statistical analyses Educational use in academic settings (with confidentiality safeguards) Criteria for evaluating requests: Scientific qualifications of the applicant: Documented research track record, publications, and relevant expertise Clarity of research objective: Submission of a clear study protocol or research proposal Scientific justification for data access: Demonstration of the necessity to access IPD Adherence to ethical principles: Commitment to non-re-identification and privacy protection No conflict of interest: Absence of commercial or competitive interests that compromise scientific integrity Access mechanism: Applicants must submit a written request to the Principal Investigator including: Brief project description (maximum 500 words) List of required data elements Letter of introduction from affiliated institution Academic CV Request reviewers: Principal Investigator and the core research team Review timeline: Maximum 4 weeks from receipt of complete application Data delivery: Following approval and signing of the Data Use Agreement, data will be provided via secure download link or confidential repository Reporting: Applicants must provide a summary of findings to the research team upon completion and properly cite the data source in any publications Grounds for rejection: Insufficient scientific justification Clear conflict of interest or unauthorized commercial use Failure to meet ethical or legal requirements

How to Access Data and Contact Information To request access to the study data, applicants may contact the Principal Investigator through one of the following methods: Principal Investigator: [Full Name] [Title and Institutional Affiliation] Preferred method of communication: Email Contact Information: Email: [email address] Telephone: [phone number with country code] Fax: [fax number - if available] Postal Address:[Department/Division][Institution/Hospital/University Name][Full Postal Address][City, Postal Code, Country] Online Access: Project Website: [URL - if available] Data Repository: [Repository name and URL, e.g., Figshare, Zenodo, Dryad - if available] Digital Object Identifier (DOI): [DOI for the dataset - if assigned] Required Documentation for Request: Completed application form (available via email) Research protocol or study proposal Applicant’s academic CV Letter of introduction from affiliated institution Signed draft Data Use Agreement Response Time: Requests will be reviewed and responded to within 4 weeks.

Step-by-Step Data Access Process and Estimated Timeline Step 1 — Initial Contact and Form Request The applicant emails the Principal Investigator to request the formal application form and the draft Data Use Agreement. Estimated time: 1–3 business days to receive a response and the forms Step 2 — Document Preparation by Applicant The applicant prepares the research protocol, academic CV, institutional letter of introduction, and completed application form. Estimated time: 1–2 weeks (depending on how quickly the institutional letter is obtained) Step 3 — Submission of Complete Application The full document set is submitted by email. The Principal Investigator confirms receipt. Estimated time: 1–2 business days for acknowledgment Step 4 — Scientific and Ethical Review The Principal Investigator and core team evaluate scientific qualifications, research justification, and ethical compliance. Additional information may be requested. Estimated time: up to 4 weeks from receipt of the complete application Step 5 — Data Use Agreement Execution Upon approval, the DUA is finalized and signed by both parties (and institutional legal/research offices if required). Estimated time: 1–3 weeks (depending on the legal processes of both institutions) Step 6 — Data Delivery After the DUA is signed, data are provided via a secure download link or confidential repository. Estimated time: 3–7 business days Total approximate process time: about 8–12 weeks (from initial contact to data receipt) Note: Factors affecting the timeline include the applicant’s speed in preparing documents, the need for institutional ethics committee review, and the complexity of DUA legal negotiations.