A unilateral fixator for adjustment of a first bone portion relative to a second bone portion. The fixator includes a telescopically adjustable strut having first and second ends and a strut axis, and first and second compound joints. The first compound joint is coupled to the first end of the strut and to a first bone clamp, and includes a first gear mechanism controlling linear and rotational motion of the first bone clamp relative to first and second axes while the first bone clamp is engaged with the first bone portion. The first and second axes are generally orthogonal to one another and to the strut axis. The second compound joint is coupled to the second end of the strut and to a second bone clamp and includes a second gear mechanism controlling linear and rotational adjustment of the second bone clamp. The first compound movable joints can rotate about the strut axis.