Table 5 Established ovine models of tendon defect

Infraspinatus tendon

Acute

Unilateral detachment

Single-row:

Arthroscopic Mason-Allen stitches

Double-row:

Arthroscopic Mason-Allen stitches

(lateral of the tendon)

Mattress stitches

(medial of the tendon)

Week 6, 12, 26

MRI–derived morphologic changes between single- and double-row rotator cuff repair and biomechanical properties [73].

Advantages:

 1. High anatomic similarity to humans.

 2. Good availability.

 3. Cost-effective.

 4. High societal acceptance as a research model.

 5. Suitable for acute studies.

 6. Larger size facilitates surgical procedures.

 7. Adequately models muscle atrophy, fatty accumulation, and other degenerative changes.

Disadvantages:

 1. Certain anatomical structures differ from human counterparts.

 2. Prone to tendon-bone interface gaps and excessive scar tissue formation post-injury.

 3. Difficult to control the locomotive activity of large animals.

 4. Post-operative management is logistically and economically challenging.

Modified Mason-Allen technique

Suture-bridge technique

Week 12

Effects of a double-row and a single-row technique on tendon blood flow [74].

Modified Mason-Allen technique

Week 12

Effects of inter-positional graft consisting PDGF-BB & a type I collagen matrix on tendon repair [75].

Week 4, 8

Effects of rhBMP-12 on the healing of rotator cuff repairs [76].

Double-row technique

6 months

Effect on rotator cuff repair of engineered tissue grafting [77].

Unilateral transection

Mattress technique

6 months

Muscle atrophy, fatty infiltration and fibrosis after repair of acute rotator cuff injury [78].

Mattress-like technique

Week 12

Biomechanical and histological characteristics of autografting in reconstruction of an infraspinatus defect by using different fixations [79].

Modified double-row technique

Week 6, 12

Mechanical, structural, and histologic quality of rotator cuff repairs augmented with an interposition electrospun nanofiber scaffold [80].

Unilateral central defect

Not specified

Week 12

Effect on rotator cuff repair of perforated anchors, or collagen scaffolds loaded with tenocytes [81].

Sharp removal

Single-row:

Arthroscopic Mason-Allen stitches

Double-row:

Arthroscopic Mason-Allen stitches (lateral of the tendon)

Mattress stitches

(medial of the tendon)

Week 1, 2, 3, 6, 12, 26

Expression of different collagen types between double-row and single-row rotator cuff repair [82].

Sharp detachment

Single-loop stitches

Modified Mason-Allen technique

4, 24 hours

Potential of tendon collagen crosslinking on improving suture pullout [83].

Bilateral detachment

Modified Mason-Allen technique

Week 4, 8

Biomechanical evaluation of the relation between number of suture anchors and strength of the bone-tendon interface [84].

Chronic

Unilateral detachment + 6, 18 weeks delayed repair + PRECLUDE wrap

Modified Mason-Allen technique

Week 12, 20, 30

Construction of chronic rotator cuff injury repair model [85].

Unilateral detachment + 4 weeks delayed repair + silicone implants

Modified Mason-Allen technique

Week 12

Effects of novel combination growth factor treatment incorporated into a PVA-Tyr hydrogel on enthesis healing [86].

Mason-Allen technique

Mattress technique

3 months

Evaluation of 2 repair techniques with respect to biomechanical function [87].

Unilateral detachment + 6 weeks delayed repair + silicone implants

Suture-bridge technique

Mason-Allen technique

Week 6, 12 post-surgery

Feasibility of using chitosan-platelet-rich plasma implants in conjunction with suture anchors to treat rotator cuff tears [88].

Unilateral osteotomy + silicone implants

Not specified

Week 14

Histological changes induced by anabolic steroids or IGF in experimentally degenerating rotator cuff tendons [89].

2 figure-of-8 stitches

Week 16

Quantification of the infraspinatus muscle work as the primary functional effect of chronic tendon tears on muscle [90].

Locked screw fixation technique

Figure-of-8 stitches

Week 0, 16, 22, 34

Adipogenic and myogenic gene expression in infraspinatus muscle in a sheep animal model of chronic rotator cuff tears [91].

Week 0, 16, 22, 34

Reversion of structural muscle changes caused by chronic rotator cuff tears using continuous musculotendinous traction [92].

unilateral release + silicone implants + denervation

2 figure-of-8 stitches

Week 0, 6, 16

Mechanisms of muscle atrophy and degeneration after rotator cuff injury [93].

Unilateral release with bone chip + silicone implants + denervation

Not specified

Week 8, 16

Tenotomy predominantly induces fatty infiltration, and denervation induces mostly muscle atrophy [94].

Unilateral detachment + 40 weeks delayed repair + silicone implants

Not specified

Week 0, 16, 40, 42, 46, 52, 75

Associated muscular changes that occur with chronic rotator cuff tears [95].