TABLE 2.
Animal Studies Investigating DBM in Tendon Repaira
| Publication | Animal Model | DBM Form | Follow-up | Groups (No.) | Methods (wk) | Findings | Positive Findingb | Quality Scorec | Evidence Level |
|---|---|---|---|---|---|---|---|---|---|
| Thangarajah et al44 (2017) | Rat model of chronic rotator cuff tear | DBM (allogenic) | 6 wk | DBM (6), dermal scaffold (6), control (no augmentation) (6) | SQ histological analysis (6), pQCT (6) | The application of DBM did not improve the composition of the healing enthesis when compared with nonaugmented controls and a commercially available scaffold. Nonaugmented repairs exhibited a significantly higher bone mineral density than DBM | No | 7 | D |
| Elnikety et al14 (2016) | Ovine patellar tendon model (large defect) | DCB (allogenic) | 12 wk | DCB (6), no control group | Gait analysis (3, 9, 12), radiographs (12), ROM (12), pQCT (12), histological analysis (12) | Functional weightbearing significantly increased from 44% at week 3 to 79% at week 12. The formation of a neoenthesis with the presence of fibrocartilage and mineralized fibrocartilage was seen in all specimens. Collagen remodeling with “ligamentization” of the DCB was observed | n/a | 6 | A |
| Thangarajah et al45 (2016) | Ovine patellar tendon model | DBM (allogenic, xenogenic) | 12 wk | Allograft DBM and mmMSCs (5), xenogenic DBM and mmMSCs (5) | Gait analysis (6, 9, 12), pQCT (12), SQ histological analysis (12) | The allograft was associated with significantly higher functional weightbearing throughout. The allogenic group showed greater remodeling of the DBM into tendon-like tissue in the region of the defect, with the presence of direct enthesis associated with more fibrocartilage | n/a | 5 | A |
| Sundar et al43 (2009) | Ovine patellar tendon model | DBM (allogenic) | 12 wk | DBM (8), control (11) | Gait analysis, (3, 6, 9, 12), radiographs, (3, 6, 9, 12), mechanical/UTS (0, 12), SQ histological analysis (6, 12) | Tendon repairs failed at a rate of 33% and 0% for the control and DBM groups, respectively. DBM augmentation resulted in significantly improved functional weightbearing and increased amounts of fibrocartilage and mineralized fibrocartilage on histology | Yes | 8 | A |
aDBM, demineralized bone matrix; DCB, demineralized cortical bone; DCM, demineralized cortical bone; mmMSCs, minimally manipulated mesenchymal stem cells; n/a, not applicable; pQCT, peripheral quantitative computer topography; ROM, range of motion; SQ, semiquantitative; UTS, ultimate tensile strength.
bWe define a positive finding as a study where DBM augmentation provided superior histological scores when compared with a nonaugmented control group.
cOut of 8.