The Collaborative International Dictionary of English v.0.48:
osteoclasis \os`te*o*cla"sis\, n. [NL. See Osteoclast.] (Surg.) The operation of breaking a bone in order to correct deformity. [1913 Webster]WordNet (r) 3.0 (2006):
osteoclasis n 1: treatment of a skeletal deformity by intentionally fracturing a bone