Systems and methods for producing minimally invasive osteotomies to correct angular deformities of bones in and about the knee are disclosed. A method includes locating a plane in which the angle exhibited by the deformity is situated. An oblique cut is then made along a surface of the bone, such that the cut is transverse to the plane in which the angle is situated. Thereafter, the bone pieces are rotated about the cut relative to one another until a desired alignment between the bone pieces is achieved. To maintain the bone pieces in alignment, a device having an elongated body for extending into a tunnel between the bone pieces is provided. The system also includes a rigid member fixedly positioned at one end of the body. The rigid member is transverse to the body to engage one bone piece. The system further includes a locking mechanism at an opposite end of the body to engage the other bone piece. The system permits the bone pieces to be pulled against one another between the rigid member and the locking mechanism.