Letter to the editor to comment on “MRI assessment of graft maturation after arthroscopic anatomical lateral ankle ligament reconstruction: One-year comparison between autograft and allograft”

Dear Editor,

We read with great interest the prospective study by Paquot et al. , which, for the first time, confirmed through multimodal MRI that there was no significant difference in maturity between autologous and allogeneic grafts one year after ankle ligament reconstruction. This study is rigorously designed, but some potential methodological limitations deserve further exploration, as these limitations may affect the interpretation and universality of the results.

Firstly, up to six different tendons were used in the allograft group in this study, and although the authors suggested that their biomechanical properties were similar to those of ankle ligaments, tendon type differences could directly affect the healing process. Studies have shown that collagen fiber alignment density and intrinsic vascularization potential vary significantly among tendons from different sources ^, . The initial vascular density of flat tendons, such as the gracilis tendon, is often higher than that of small foot tendons, which may accelerate revascularization after transplantation. Moreover, the differences in the diameter and arrangement pattern of collagen fibers can affect the remodeling rate, and this structural heterogeneity may lead to asynchronous maturation rates. Therefore, the failure to conduct stratified analyses of graft types may mask intra-group differences and weaken the reliability of the results.

In addition, in the study, bio-composite material extrusion screws were used for fixation in the talus and calcaneal tunnels, while Endobutton suspension devices were employed on the fibular side. This methodological heterogeneity may become a potential confounding factor affecting the results. Different fixation techniques can create completely different mechanical environments at the graft–bone channel interface (such as compression, stability, and suspension fretting). Existing evidence indicates that the fixation method itself can significantly affect the imaging manifestations of healing . Therefore, the observed graft–bone interface signals showed no difference, which might mask the different effects of different fixation methods on the healing process.

Finally, although this study confirmed the maturity of the graft on imaging through multimodal MRI, it should be noted that ligamentization on imaging does not entirely equate to functional biomechanical stability. It has been repeatedly confirmed in the related studies of anterior cruciate ligament reconstruction that there is only a limited correlation between the graft maturity shown by MRI and objective measurements of joint laxity . Therefore, if future research can combine MRI parameters with objective stress site X-rays (such as ankle stress radiographs) or functional biomechanical tests, it will be able to more comprehensively assess the true functional status of the graft, and may identify patient subgroups with mature imaging but unstable biomechanics.

In conclusion, future research needs to comprehensively verify the role of allogeneic grafts in the reconstruction of lateral ankle ligaments and optimize clinical decisions through standardized graft screening, unified fixation techniques, and integrated functional biomechanical assessment.