J Reconstr Microsurg
DOI: 10.1055/s-0040-1716870
Original Article

Histological Assessment of Wallerian Degeneration of the Rat Tibial Nerve Following Crush and Transection Injuries

James M. Kerns
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
,
James S. Walter
2  Hines Veterans Affairs Hospital Research Service, Hines, Illinois
,
Michael J. Patetta*
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
,
Anshum Sood*
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
,
Awais K. Hussain*
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
,
Joyce J. Chung*
3  University of Illinois College of Medicine, Chicago, Illinois
,
Abhishek Deshpande*
3  University of Illinois College of Medicine, Chicago, Illinois
,
Justin T. DesLaurier*
3  University of Illinois College of Medicine, Chicago, Illinois
,
Raymond A. Dieter
2  Hines Veterans Affairs Hospital Research Service, Hines, Illinois
,
Maria Siemionow
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
,
Figen A. Seiler
4  Research Resources Center, University of Illinois Chicago, Chicago, Illinois
,
Farid M.L. Amirouche
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
,
Mark H. Gonzalez
1  Department Orthopaedic Surgery, University of Illinois Chicago, Chicago, Illinois
› Author Affiliations
Funding This research was supported in part by Departmental Funds. This work made use of instruments in the Electron Microscopy Service (Research Resources Center, UIC).

Abstract

Background Wallerian degeneration (WD) following peripheral nerve injury (PNI) is an area of growing focus for pharmacological developments. Clinically, WD presents challenges in achieving full functional recovery following PNI, as prolonged denervation of distal tissues for an extended period of time can irreversibly destabilize sensory and motor targets with secondary tissue atrophy. Our objective is to improve upon histological assessments of WD.

Methods Conventional methods utilize a qualitative system simply describing the presence or absence of WD in nerve fibers. We propose a three-category assessment that allows more quantification: A fibers appear normal, B fibers have moderate WD (altered axoplasm), and C fibers have extensive WD (myelin figures). Analysis was by light microscopy (LM) on semithin sections stained with toluidine blue in three rat tibial nerve lesion models (crush, partial transection, and complete transection) at 5 days postop and 5 mm distal to the injury site. The LM criteria were verified at the ultrastructural level. This early outcome measure was compared with the loss of extensor postural thrust and the absence of muscle atrophy.

Results The results showed good to excellent internal consistency among counters, demonstrating a significant difference between the crush and transection lesion models. A significant decrease in fiber density in the injured nerves due to inflammation/edema was observed. The growth cones of regenerating axons were evident in the crush lesion group.

Conclusion The ABC method of histological assessment is a consistent and reliable method that will be useful to quantify the effects of different interventions on the WD process.

* These authors contributed equally to this work.




Publication History

Received: 06 July 2020

Accepted: 15 August 2020

Publication Date:
24 September 2020 (online)

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