Growth Factor and Intense Pulse Light in Flexor Tendon Repair: A Biomechanical Study at Strength and Gap Resistance

Background: Flexor tendon injuries are extremely common and they are usually the result of incised traumatic glass or knife injury. The process of tendon healing is a complicated and exceptionally-regimented mechanism that is originated and monitored by a vast number of diverse molecules. One of the most pivotal groups of mediators that are crucial to the healing process are growth factors (GF). Intense pulse light (IPL) can lead to evidence of new collagen formation with associated clinical improvement in tissue healing. The biological benefit of Intense pulse light (IPL) relies on judicious photothermolysis, where heat driven radiation is dissipated and focused at the cellular level. The aims of this study is to set out the effect of growth factor and IPL on healing following a tendon repair. Methods: Bovine common digital extensor tendons (CDET) were used as an ex vivo model. 44 tendon repairs were performed by the lead author using 2.5 × magnification loupes and standard instruments. Clamped tendons were assigned into the following groups; control, IPL, GF, IPL and GF. After culturing, biomechanical testing was carried out using monotonic tensile testing with displacement-controlled uniaxial tension to failure. Results: The mean values for ultimate tensile stress (UTS) for the control group was 53.51 N, for IPL it was 51.15 N, for growth factor was 70.10 N and for combined growth factor and IPL it was 75.16 N. Conclusions: This study showed significant improvement in UTS when repaired tendons were cultured with growth factor compared to control and IPL. This would suggest a biomechanical advantage for tendon healing.