Background: Little has been written about the functional outcome of
patients treated with bone transport to reconstruct a distal tibial defect.
The aim of this study was to investigate the functional capabilities of
patients who had undergone reconstruction with distraction osteogenesis for
the treatment of a distal tibial defect in one lower limb.
Methods: At least eighteen months after completion of treatment,
eight patients who had no pain and were able to walk and climb stairs without
difficulty performed isometric ankle plantar flexion maximum voluntary
contractions while the electromyographic activity of the tibialis anterior and
triceps surae muscles was simultaneously recorded. Seven of the patients also
underwent gait analysis. Data for the involved limb were compared with those
collected for the contralateral limb.
Results: During gait, stance time (p = 0.01), the plantar flexion
angular displacement and peak moment developed during the second half of
stance (p < 0.046), and the amount of ankle power generated (p = 0.02) were
significantly decreased in the involved limb compared with the contralateral
limb. Similar decreases were observed in the plantar flexion (p = 0.01) and
dorsiflexion (p = 0.01) maximum voluntary contractions and the corresponding
electromyographic activity (p = 0.01).
Conclusions: These results suggest that adaptive changes had
occurred at the level of the transported muscles, which affected both routine
and maximal effort capabilities. These findings contribute to our
understanding of the functional limitations of patients who have undergone
bone transport with its obligatory shortening of muscle length.
Level of Evidence: Therapeutic study, Level IV. See
Instructions to Authors for a complete description of levels of evidence.