Autologous Fat Grafting in the Upper Extremity: Defining New Indications

An immunohistochemical and biomechanical evaluation of the effect of fat graft on tendon healing

AIM

To investigate the efficacy of fat grafting in primary tendon healing through immunohistochemical and biomechanical examinations.

MATERIAL AND METHOD

The study material comprised a total of 10 male Sprague-Dawley rats, each approximately 10 weeks old. All 10 rats were operated on bilaterally. The right Achilles tendon in all the animals was defined as the study group. The tendon was cut and then repaired, and then fat graft was applied to the repair area. The left Achilles tendon of all the rats constituted the control group. The tendon was cut and repaired with no further application. After 4 weeks, the rats were euthanised and samples were taken from the tendons for immunohistochemical and biomechanical examinations.

RESULTS

In the biomechanical evaluations, no statistically significant difference was determined between the groups in respect of peak load and stiffness values (p: .068, p: .089, respectively). In the histopathological evaluation, the tenocyte value of the study group was superior to that of the control group (p: .04). No statistically significant differences were determined between the groups in respect of the other histopathological parameters. In the immunohistochemical evaluations, the type I collagen and TGF values of the study group were found to be higher than those of the control group (p: .011, p: .012, respectively).

CONCLUSION

Compared to stem cell applications, the use of fat grafting is clinically easy to apply, has low costs, and has been shown to contribute to tendon healing at an immunohistochemical level with increased collagen and TGF beta values.

The Clinical Efficacy of Fat Injection on the Repair of Hand Flexor Tendon: A Randomized Clinical Trial

Background

In recent years, special attention has been paid to minimally invasive and conservative methods in addition to conventional surgical methods to repair tendon damage. In this regard, the effect of fat injection and graft has been of great interest due to its potential in accelerating tissue repair. We aimed to assess the clinical efficacy of fat injection along with conventional approach in patients with flexor tendon injury.

Methods

In this randomized clinical trial, 64 patients were randomly scheduled for tendon repair using the usual modified Kessler four-strand method alone or tendon repair using four-strand method and fat injection on the proximal and distal sides of the repair site in the Hazrat Fatemeh Hospital, Tehran Province, Iran in 2022 (IRCT20221206056723N1). Patients were followed-up for eight weeks regarding the function status of the repaired tendon (using Strickland grading test), range of motion (by physical examination) and flexion and extension gaps (by imaging).

Results

In the eighth weeks after the treatment, the average Strickland score was significantly higher in the group receiving fat injection (P: 0.009 ). In the two pointed times, the mean range of motion was significantly higher and the mean flexion and extension gaps were significantly lower in those who received fat injection. None of the procedural side effects were observed in the fifth and eighth weeks after the treatment.

Conclusion

Fat injection along with usual surgical treatment for tendon repair accelerates and improves tendon function and range of motion.