Abstract
The extensor pollicis longus (EPL) tendon is responsible for thumb extension and normally passes over Lister's tubercle which acts as a pulley. During procedures in which access to the radiocarpal joint is required through a dorsal approach, the EPL tendon must be relocated toward the radial side of the wrist. However, in the clinical setting, we have observed that some patients have limited thumb extension following relocation surgery. In order to better understand this effect, a rigid body mathematical model was developed to evaluate the effect of EPL tendon relocation on thumb extension. Simulated thumb extensions were performed for both the natural and relocated positions and the model was calibrated and verified with cadaveric experimental data. Relocating the EPL tendon increased the moment arm resulting in an improved mechanical advantage. However, it also shortened the path causing tendon slack and reduced muscle force generation. When these two effects were combined, thumb extension decreased with tendon relocation and the thumb extension force was reduced. These results support clinical studies and observations that suggest displacement of the EPL tendon would result in loss of function or deformity. These results are a first step toward developing a quantitative understanding of the effect of EPL relocation. Further studies including more advanced models and clinical trials are needed before definite conclusions can be made regarding the implications of this research.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call