The Effect of Midcarpal Versus Total Wrist Fusion on the Hand's Load Distribution During Gripping.
PURPOSE
To analyze the total grip force and load distribution of the hand with midcarpal fusion (MCF) and total wrist fusion (TWF).


METHODS
Twelve patients with unilateral TWF and 12 patients with unilateral MCF were assessed at an average 64 months (range, 19-100 months) postoperatively. The total grip force and load distribution of both hands were measured by the Manugraphy system using 3 cylinder sizes. The load applied to 7 anatomical areas of the hand during cylinder grip was analyzed, comparing the operated and the nonsurgical hands.


RESULTS
For the 100 mm and 150 mm cylinders, a significantly lower total grip force was found in hands operated with either TWF or MCF. For the 200 mm cylinder, there was a significant difference between nonsurgical hands and those with MCF but not between nonsurgical hands and those with TWF. For the 100 mm cylinder, the difference between nonsurgical and operated hands was greater in hands with TWF than those with MCF. For the load distribution of the hand, no differences between the operated and the nonsurgical hand were found for either MCF or TWF.


CONCLUSIONS
MFC and TWF resulted in a reduced cylinder grip force. With respect to the load distribution, neither procedure influenced the relative contribution that each area of the hand produced during cylinder grip.


TYPE OF STUDY/LEVEL OF EVIDENCE
Therapeutic III.