Research question:
Tibial bone distraction (tibial bone transverse transport, TTT) is a promising limb-preserving treatment approach for advanced diabetic foot ulcers (DFU). However, the evidence available to date is limited by heterogeneous endpoints and inconsistent measurement instruments. The aim of this study was to develop an internationally applicable core outcome set (COS) to standardize endpoint measurement in clinical studies on the efficacy of TTT in DFU at Wagner-Armstrong stage = 2B.
Methodology:
The COS was developed in accordance with the COS-STAD recommendations using the MRC framework for complex interventions. In a participatory, multi-stage process, three outcome domains were defined: (1) clinical outcome measures (biological mechanism of action), (2) patient-reported outcomes (benefits and burdens), and (3) health economic outcomes (system perspective). Over a project period of twelve months (02/2025–02/2026), three two-day workshops were held with a total of 21 stakeholders (patients and relatives, clinical experts, health economists, representatives of patient organizations). Candidate endpoints were generated from literature reviews, qualitative interviews, and patient workshops, iteratively consolidated, and evaluated using structured consensus procedures. The selection of patient-reported instruments was additionally based on comprehensibility, acceptance, and processing.
Results:
There was unanimous consensus that wound healing was the primary clinical outcome. The collection of invasive and non-invasive parameters (including blood samples and perfusion measurements) was considered acceptable and practicable. All patient-reported instruments tested (EQ-5D-5L, PBI-W, Wound-QoL) achieved high approval rates with low survey burden (< 10 minutes total processing time) and were unanimously recommended for integration into the COS. Health economic parameters were identified as essential for future efficacy and implementation studies.
Conclusions:
The developed COS provides a consensus-based, practical basis for harmonizing endpoint assessment in future TTT studies in DFU. The systematic integration of clinical, patient-centered, and health economic outcomes can improve the comparability of studies and sustainably strengthen the quality of evidence. The COS is suitable as a minimum standard for prospective clinical studies and represents an important step toward the methodologically sound evaluation of limb-preserving treatment strategies.
L. P. Weimer1 (Hauptforscher), L. Lüdtke1, N. Albrecht1, K. Laquai1, M. Vomhof2, A. Icks2, N. Kairies-Schwarz2, A. Clames2, S. Ries3, M. Czihal4, W. Böcker1, P. H. Thaller1 and M. Laubach1
1Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), LMU University Hospital, LMU Munich, Munich, Germany
2Institute for Health Services Research and Health Economics, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
2Institute for Health Services Research and Health Economics, Centre for Health and Society, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
3Protestant University of Applied Sciences Ludwigsburg, Ludwigsburg, Germany
4Medical Clinic and Policlinic IV, Division of Vascular Medicine, LMU University Hospital, LMU Munich, Munich, Germany
Disease Category: Orthopaedics & trauma
Disease Name: Diabetic foot ulcer/ulceration
Age Range: 18 - 120
Sex: Either
Nature of Intervention: Surgery
- Clinical experts
- Consumers (patients)
- Families
- Patient/ support group representatives
- Researchers
- COS for clinical trials or clinical research
- COS for practice
- Interview
- Literature review
- Semi structured discussion
- Survey
The COS was developed in accordance with the COS-STAD recommendations using the MRC framework for complex interventions. In a participatory, multi-stage process, three outcome domains were defined: (1) clinical outcome measures (biological mechanism of action), (2) patient-reported outcomes (benefits and burdens), and (3) health economic outcomes (system perspective). Over a project period of twelve months (02/2025–02/2026), three two-day workshops were held with a total of 21 stakeholders (patients and relatives, clinical experts, health economists, representatives of patient organizations). Candidate endpoints were generated from literature reviews, qualitative interviews, and patient workshops, iteratively consolidated, and evaluated using structured consensus procedures. The selection of patient-reported instruments was additionally based on comprehensibility, acceptance, and processing.