An Investigation of a Novel Tendon Transfer Surgery for High Median-Ulnar Nerve Palsy in a Chicken Model

ABSTRACT

Purpose: The state-of-the-art tendon transfer surgery for high median-ulnar nerve palsy involves directly suturing four finger flexor tendons to one wrist extensor muscle. This couples finger flexion limiting the patient's ability to grasp objects. Therefore, we propose a new approach to attach a novel passive implant to the extensor digitorum longus tendon in order to create a differential mechanism in situ. The implant is expected to enable the fingers to adapt to an object's shape during grasping. Chickens have been used as a model in tendon research, but studies have primarily focused on the digital flexor tendon mechanism. Thus, the aim of this study was to explore the feasibility of the chicken model for extensor tendon research and to validate the surgical technique for a new approach to tendon transfer surgery. Materials and Methods: Twenty-nine chickens were randomly divided into three groups: implant (n = 12), sham (n = 10), and control (n = 7). Postoperative healing and complications were documented. Results: Surgery was successful in all chickens. All animals healed appropriately by Day 16 postoperatively. Chickens in the implant group experienced significantly more intermittent toe-knuckling gait than the sham group (p = 0.001). Conclusions: The described surgical technique allowed for successful application of a novel implantable passive mechanism in a live chicken model. In combination with previous work, findings from the present study further validated a novel tendon-transfer surgery for high median-ulnar nerve palsy. Based on the degree of intermittent abnormal gait experienced by the implant group, refinement to the implant design is warranted in future studies.

Keywords::

• chicken
• extensor tendon
• implant
• tendon transfer surgery
• high median-ulnar nerve palsy

ACKNOWLEDGMENT

The authors thank OSU Laboratory Animal Resources Center (LARC) for their support in pre- and postoperative animal care and handling. The authors also thank Maureen Larson, Justin Casebier, and Jacob Mandich for their assistance in data collection during the study.

FUNDING

This work was supported in part by the OSU Venture Development Fund and NSF CBET 1554739. This work was also supported in part by the Office of the Assistant Secretary of Defense for Health Affairs, through the Joint Program Committee 8 (JPC8), Clinical and Rehabilitative Medicine Research Program (CRMRP), Neuromusculoskeletal Injuries Research Award (NIRA), Funding Opportunity Number: W81XWH-15-JPC-8/CRMRP-NMSIRA, under Award No. W81XWH-16-1-0794. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.