Efficacy of Single-Dose Radiotherapy in Preventing Posttraumatic Tendon Adhesion

Background and Aim Posttraumatic peritendinous adhesion is the greatest obstacle to achieve normal tendon function following lacerations of extrinsic flexor tendons of the hand. In this study, we aimed to evaluate whether single-dose radiotherapy (RT) has the potential to modulate intrasynovial tendon adhesions. Materials and Methods A total of 80 tendons from the third to fourth flexor profundus of both hind paws of 20 adult New Zealand rabbits were used in this study. Rabbits in the RT group received 3 Gy of X-irradiation in a single fraction. Histopathological evaluation of longitudinal sections of tendons was made using the Tang grading system for peritendinous adhesions. Intratendinous quality of the healing tissue in the laceration zone was assessed using a modified Movin scale. Results Adhesion and inflammatory response were greater in the RT group (p˂0.001). Tendon healing in the radiation group was found to be more uniform and organized compared with the control group. However, this difference was not statistically significant. The nuclei of the tenocytes in the radiation group showed a closer resemblance to normal tendon tissue when compared with the control group (p=0.007). Conclusions Despite RT's certain advantages such as extracorporeal use, anti-inflammatory effect, and homogenous tissue penetration, 3-Gy X-irradiation resulted in increased peritendinous posttraumatic adhesion, possibly due to dose imbalance. Increased roundness in the tenocyte nuclei was present in the RT group. Studies with different dosing regimens and a higher number of subjects are necessary to establish an ideal dose suppressing the synovial response without compromising tendon healing.