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Updated: Jun 20, 2026

Evaluation of Biomaterials for Bladder Augmentation using Cystometric Analyses in Various Rodent Models
Published on: August 9, 2012
Reconstruction and Regeneration of Composite Fingertip Injuries Using Acellular Bladder Matrix
Usman Zareef1, Anna Green2, Caroline Moore3
1Department of Orthopaedic Surgery, University of Maryland School of Medicine, Baltimore, MD.
Purpose:
Traumatic fingertip amputations are one of the most encountered injuries in the emergency department requiring evaluation by a hand surgeon. Current management strategies vary widely. We describe the use of acellular urinary bladder matrix (UBM) in complex distal fingertip injuries involving bone, soft tissue, and nailbed.
Methods:
A prospective cohort of 47 patients with proximal fingertip amputations (36 Allen zone III and 15 Allen zone IV) underwent UBM application with resultant fingertip regeneration. Patients received the first application in the operating room. Subsequent applications were reapplied weekly in the clinic setting until fibrinous granulation tissue was observed (average 2.5 total applications). Patients performed daily dressing changes until regeneration was achieved.
Results:
The average time to regeneration was 8.4 weeks. The mean length deficit compared to the contralateral fingertip was 3.6 mm for zone 3 and 4.8 mm for zone 4 injuries. The static 2-point discrimination of the injured fingertip was 1.2 mm less sensitive compared to the contralateral uninjured finger in zone 3 injuries and 1.1 mm in the zone 4 cohort. Overall patient satisfaction measured on a 10-point Likert scale was 9.5. Seven complications were observed: 5 hook nail deformities, one bony exostosis requiring surgical excision, and one case of pyogenic granuloma.
Conclusion:
Application of UBM is a reliable way to promote composite regeneration of Allen III-IV fingertip injuries. Its use resulted in excellent patient satisfaction with minimal complications encountered. Urinary bladder matrix should be considered for use in the treatment of proximal fingertip amputations.
Level Of Evidence:
Therapeutic IV.
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