Table 5.
Established ovine models of tendon defect
| Tendon(s) | Types of model | Defect procedure | Repair procedure | Timepoints | Objective(s) | Comments |
|---|---|---|---|---|---|---|
| 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]. |