PSI - Issue 68

E. Koumantou et al. / Procedia Structural Integrity 68 (2025) 106–111 E. Koumantou et al. / Structural Integrity Procedia 00 (2025) 000–000

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5

Fig. 4. Typical (for most ligaments and tendons) force-displacement plot.

As anticipated, a difference in stiffness by approximately 10% was observed between the control group and both study groups, reflecting the increased vulnerability of repaired tendons to rupture compared to intact ones. However, the repair method, whether with or without MSCs, did not appear to influence stiffness. Furthermore, Group MSC specimens demonstrated increased elongation until failure compared to Group TFL (Fig. 5). This may be attributed to inherent differences in elasticity between muscle tissue and the scar tissue formed at the suture site, influenced poten tially by the presence of MSCs. A histological evaluation is necessary to confirm this preliminary result.

Table 1. Results of the biomechanical testing. Group Failure load [N]

Displacement [mm]

Stiffness [N/mm]

Non-Operated (Control)

Mean

494.3 116.9 491.0

5.4 2.5 4.7 7.5 3.3 8.6

227.8

SD

59.7

Median

222.7

TFL Group

Mean

104.9

33.1

SD

35.7 99.1

4.4

Median

30.9

MSC Group

Mean

142.3

15.4

33.2

SD

26.8

6.4

5.9

Median

135.0

15.4

29.8

4. Discussion and Conclusions The Group TFL, where SSP ruptures were repaired using fascia lata allografts, and Group MSC, where MSCs were incorporated into the repair, showed distinct mechanical properties compared to the control group. Notably, Group MSC specimens exhibited higher average tensile fracture load than the TFL Group, suggesting a potential improve ment in mechanical strength and a decreased risk of re-tears following repair. This could highly impact the postoper ative life of patients in everyday tasks. However, it is noted that the maximum load values are affected by geometric characteristics of the tendons such as cross-section area and morphology and should not be interpreted in isolation.