Preliminary Feasibility Implementation of Post-Decompressive Craniectomy 3D-Printed Externally Applied Cranial Orthosis (PEACO) During Inpatient Rehabilitation: A Retrospective Cohort Study Reporting Short-Term Tolerability and Patient/Caregiver-Repo

A minimally monitored clinical protocol demonstrated preliminary short-term feasibility and tolerability: 18/23 (78.3%) fitted patients were confirmed compliant, with 18/20 (90%) respondent compliance and three patients of unknown status, without serious adverse events. Longer follow-up studies are needed to assess sustained compliance throughout the pre-cranioplasty period. Future research should standardise materials and outcome measures to inform clinical practice guidelines. Background/Objectives: 3D-printed externally applied cranial orthosis (PEACO) represents an emerging solution for temporary cranial protection, though evidence remains limited regarding real-world implementation using minimally monitored clinical protocols. Methods: Retrospective cohort study conducted at a 121-bed rehabilitation centre in Singapore (November 2022–November 2025). Adults >21 years, >3 weeks post-DC with healed wounds and available caregivers were included. PEACO devices were individually designed from CT stereotaxis scans using contralateral hemi-cranium mirroring and fabricated using Ultra-durable Resin. Rehabilitation therapists fitted devices using progressive wearing schedules. T0 outcomes (30 min post-fitting) included therapist-observed pain, redness, skin imprints, and pruritus. T1 outcomes (at least 2 weeks post-fitting) included wearing duration, cosmesis ratings (0–10 scale), compliance, and adverse events via digital surveys. Exploratory comparisons using descriptive analysis were performed to compare outcomes from 2021 (n = 10) and 2025 (n = 23) cohorts. Results: Twenty-three patients (14 males, median age 56.0 years) were fitted with PEACO at median 67 days post-DC, (13 traumatic brain injury, 10 stroke). At T0, primary reprinting for poor fit was required in 3/23 (13.0%), 18/23 (78.3%) fitted patients were confirmed compliant, 18/20 (90%) were compliant with responder feedback; 2/20 (10.0%) were non-compliant, with three patients of unknown status. At T0, 9/23 (39.1%) had therapist-observed mild, transient adverse events, with no reported wound dehiscence. At T1, among 18 respondents: 16/18 (88.9%) wore PEACO ≤4 h/day, 7/18 (38.9%) reported self-limiting discomfort or transient skin changes at T1, median cosmesis rating was 6.0/10. At T1 assessment, no falls with head impact occurred. Clinical Trials Registration: ClinicalTrials.gov NCT07122752.