Remodeling of the Fibula Stump After Transtibial Amputation.

Aim: To study the peculiarities of peroneal stump remodelling after transtibial amputation in the process of prosthesis usage. Material and Methods: A histological study of the ends of the stumps of the fibula in 68 patients was performed. Terms after amputation: 2-8 years. Results: In the 1st group the stumps with the reparative process completion were formed. In the 2nd group there were sharp disturbances of the reparative process with the formation of the cone-shaped end. In the 3rd group there was a pronounced periosteal bone formation with changes in the shape and structure of bone tissue and incompleteness of the reparative process. Conclusion: Absence of balloting of the fibula stump and dense overlapping of the medullary cavity by muscles promotes complete remodelling of the fibula remnant with preservation of its organicity. Pathological remodelling of the fibula stump occurs due to its hypermobility, repeated traumatisation of the forming regenerate, neuritis of the peroneal nerve, osteogenesis disorders and structural and functional mismatch of the bone tissue to the loading conditions in the prosthesis. Morphological signs of pathological remodelling are the lack of completion of reparative regeneration, intensive bone tissue remodelling lasting for years with pronounced resorption and appearance of immature bone structures, fractures of the cortical diaphyseal layer, residual limb deformities with formation of a functional regenerates, narrowing and closure of the medullary canal with conglomerate with soft tissue inclusions. The anatomical inferiority of bone tissue formed in the process of remodelling of the fibula remnant creates a threat of stress fracture.