Three-dimensional hepatic collagen scaffold for chronic wounds involving exposed bone and tendon: case series and benchmark panel

Abstract

Background
Chronic wounds with deep structural involvement (e.g., tendon or bone exposure in advanced diabetic foot ulcers [DFUs] and full-thickness stage IV pressure ulcers) are clinically challenging due to volume deficit, bioburden risk, and barriers to durable granulation and closure when flap coverage is not feasible.

Objectives
To describe outcomes from a locked case-series evidence package using a three-dimensional acellular collagen scaffold (3D-ACM; Miro3D, Reprise Biomedical, Plymouth, MN) and to contextualize outcomes against a prespecified DFU/PU comparator benchmark panel.

Methods
A primary 3D-ACM dataset was standardized using prespecified rules (DFUs required explicit tendon exposure in source text; stage IV pressure ulcers were treated as exposed-structure cases by prespecified rule). Outcomes were extracted descriptively at reported time points, including closure and, when reported, tunneling/undermining milestones. A targeted comparator panel (DFU/PU) was assembled for contextual benchmarking at each study's prespecified primary assessment timepoint.

Results
The locked dataset comprised 5 exposed-structure cases (2 DFU with tendon exposure; 3 stage IV pressure ulcers). Documented closure occurred in 4/5 cases between Day 42 and ~20 weeks. One stage IV pressure ulcer achieved tunneling resolution by Day 56 but was lost to follow-up prior to reported closure. The comparator panel included 6 DFU studies and 2 PU randomized trials with heterogeneous designs, follow-up windows, and endpoint definitions.

Conclusions
In this non-comparative exposed-structure case series, documented closure occurred in most cases with available follow-up, and deep-wound improvement (tunneling resolution) was captured when reported. Findings support prospective evaluation using standardized, time-anchored endpoints in volume-deficit wounds.