In vivo healing after capsular plication in an ovine shoulder model

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomedical Engineering

Background:

• Shoulder instability management traditionally focuses on isolated Bankart lesions.
• Arthroscopic techniques for capsular laxity are less studied, with no prior animal research on capsular plication healing.
• Evaluating healing potential is crucial for advancing minimally invasive orthopedic procedures.

Purpose of the Study:

• To compare the histological capsular healing of an open capsular plication (simulating arthroscopic plication) with an open traditional capsular shift.
• To assess tissue injury differences between the two surgical techniques in an animal model.

Main Methods:

• An in vivo study using 26 skeletally mature sheep, randomized into capsular plication and capsular shift groups (n=13 each).
• Sham operations (n=4) and analysis of normal control shoulders were included.
• Histological evaluation by a blinded pathologist using H&E and polarized light microscopy, assessing fibrosis, degeneration, necrosis, and collagen formation.

Main Results:

• Both capsular plication and open shift groups demonstrated capsular healing via fibrosis.
• No significant differences in fibrosis, granuloma formation, or vascularity were observed between groups.
• The open shift group showed significantly more mucinous degeneration and fat necrosis compared to the plication group.

Conclusions:

• Histological capsular healing is equivalent between capsular plication and open capsular shift.
• The capsular plication technique appears to cause less tissue injury than the traditional open shift.
• This study provides basic science evidence supporting the efficacy of arthroscopic capsular plication for shoulder instability.