Scanning electron microscopy of repaired tendon and pseudosheath

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Histology

Background:

• Tendon injuries require understanding the biological mechanisms of repair.
• The role of the tenosynovium in tendon healing is crucial.
• Surface morphology changes during tendon repair are not fully elucidated.

Purpose of the Study:

• To investigate the surface healing process of transected and resected digital flexor tendons in hens.
• To examine the surface structure changes following silicone rod implantation for tendon sheath repair.
• To compare the repair timelines and morphology between visceral and parietal tendon sheath layers.

Main Methods:

• Scanning electron microscopy (SEM) was used to analyze tendon surface structures.
• Observations were made at one, two, and three weeks post-injury for transected tendons.
• SEM was also applied to assess tendon sheath repair after silicone rod implantation.

Main Results:

• Initially, sutured tendons showed fibrin and blood cells; later, lining cells and fibrils appeared.
• Resected tendons exhibited similar healing, with lining cells originating from the synovium.
• Silicone rod implantation led to fibroblast-like cell and fibril formation, with sheath regeneration by four weeks.

Conclusions:

• Tendon repair involves surface regeneration by tenosynovial cells, forming a new lining.
• The repair process for visceral and parietal tendon sheath layers is similar in timing and form.
• Further studies comparing these findings with human tendon adhesions are warranted.