2017 ISAKOS Biennial Congress ePoster #322

 

Graft Augmentation Of Fascia Lata For The Massive Rotator Cuff Tear In A Rabbit Model

Takeshi Kataoka, MD, Kobe, Hyogo JAPAN
Takeshi Kokubu, MD, PhD, Kobe JAPAN
Tomoyuki Muto, MD, PhD, Kobe JAPAN
Yutaka Mifune, MD, PhD, Kobe JAPAN
Atsuyuki Inui, MD, PhD, Kobe JAPAN
Fumiaki Takase, MD, Kobe JAPAN
Yasuhiro Ueda, MD, Kobe JAPAN
Takashi Kurosawa, MD, Kobe JAPAN
Ryosuke Kuroda, MD, PhD, Kobe, Hyogo JAPAN

Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, kobe, Hyogo, JAPAN

FDA Status Not Applicable

Summary

The fascia lata autograft augmentation could be one of the effective treatments for massive rotator cuff tears.

Abstract

Introduction

Rotator cuff tears cause chronic pain and severe dysfunction. Excellent outcomes of arthroscopic rotator cuff repair for small and medium tears have been recently reported. In contrast, large and massive rotator cuff tears are challenging for surgeons. For repair of massive rotator cuff tear, various surgical procedures, such as musculotendinous transfer or synthetic materials are available. Fascia lata augmentation for massive rotator cuff tear has shown a good clinical result. However its biological effect during early healing period is not clearly understood. The purpose of this study was to evaluate the efficacy of fascia lata augmentation at the early healing period of rotator cuff tear using a rabbit rotator cuff defect model.

Methods

This investigation was approved by the Animal Research Committee of our institution. General anesthesia was administered to 24 female Japanese white rabbits (2.7–3.5 kg). To create a rotator cuff defect, the infraspinatus tendon (5 mm in width and 5 mm in length) was resected from the greater tuberosity. Edge of the tendon was sutured directly to the humeral head by 4-0 nylon suture (re-attachment group: group R). On the contralateral shoulder, a fascia lata autograft was harvested and transplanted on the rotator cuff repaired site (augmentation group: group A). As the control, we set non-rotator cuff tear group (control group). Histological examinations were conducted at 4 and 8 weeks postoperatively using hematoxylin eosin, safranin O, and picrosirius red stainings. Picrosirius red staining showed that type I collagen was stained yellow, and type III collagen was stained green. For mechanical analysis, ultimate failure load and stiffness of the tendon-humeral head complex were performed at 4 and 8 weeks postoperatively with a tensile sensor (AG-I SHIMAZU Co, Kyoto, Japan). The Steel-Dwass test was performed to compare the three groups. P values less than 0.05 were considered significant.

Results

Histologically, there was no major difference in hematoxylin eosin and safranin O stainings between the three groups, whereas the picrosirius red staining showed that type III collagen was more strongly expressed in group A than in group R at 4 and 8 weeks. The ultimate failure load of the tendon-humeral head complex were 79.7 ±4.9 N in group A and 66.7 ±8.3 N in group R at 4 weeks postoperatively, which showed statistically significant difference (p<0.05), and that of group A was similar with that of control (85.6±11.3 N). However, at 8weeks, there was no significant difference among the three groups. The stiffness did not show a significant difference between group A and R, but the stiffness of both groups were significantly lower than that of control at 4 weeks.

Discussion

Biological and mechanical contribution of the fascia lata augmentation for massive rotator cuff tear was analyzed in this study. Type III collagen was reported to be expressed during the tendon healing process. Biological action similar to natural ligament healing occurred around the fascia lata grafts, and type III collagen gradually was replaced by type I collagen as the tissue matured. It was reported that type III collagen enhanced the biomechanical properties of the graft. Our results suggested that the fascia lata augmentation could stimulate biological healing and provide initial fixation strength of the repaired rotator cuff.