An external fixation system for a bone, comprising: - a proximal frame defining a continuous proximal boundary; - a distal frame defining a continuous distal boundary, wherein at least one of the proximal frame or the distal frame comprises three separate and spaced apart continuous attachment surfaces oriented in a three-dimensional configuration and defining a tri-lobe frame cross section, each attachment surface defining an attachment lobe with a curved cross section, the attachment lobes arranged in a triangular configuration; and - at least one frame connector configured for interconnecting the proximal and distal frames (102,104) at any position along one of the attachment lobes of the at least one of the proximal frame or the distal frame, wherein the frame connector comprises a compliant mechanism for transmitting an adjustable compressible force to the bone, wherein the compliant mechanism is configured for transmitting a compressive force of constant magnitude to the bone during non load-bearing use, wherein the compliant mechanism comprises: - first and second members (154,156) telescopically interconnected and movable between a first position in which a gap therebetween is substantially closed and a second position in which the gap therebetween is open, the first connector member including a threaded portion, and an elongated slot defined on the threaded portion; - a biasing member operable to transmit compression force when the gap is open; - an activation knob rotatable for opening the gap and activating the biasing member; and - a force-selector knob threadably connected to the threaded portion of the first connector member, the force-selector knob rotatable for engaging a pin, the pin transverse to the slot and movable along the slot for opening the gap. - a proximal frame defining a continuous proximal boundary; - a distal frame defining a continuous distal boundary, wherein at least one of the proximal frame or the distal frame comprises three separate and spaced apart continuous attachment surfaces oriented in a three-dimensional configuration and defining a tri-lobe frame cross section, each attachment surface defining an attachment lobe with a curved cross section, the attachment lobes arranged in a triangular configuration; and - at least one frame connector configured for interconnecting the proximal and distal frames (102,104) at any position along one of the attachment lobes of the at least one of the proximal frame or the distal frame, wherein the frame connector comprises a compliant mechanism for transmitting an adjustable compressible force to the bone, wherein the compliant mechanism is configured for transmitting a compressive force of constant magnitude to the bone during non load-bearing use, wherein the compliant mechanism comprises: - first and second members (154,156) telescopically interconnected and movable between a first position in which a gap therebetween is substantially closed and a second position in which the gap therebetween is open, the first connector member including a threaded portion, and an elongated slot defined on the threaded portion; - a biasing member operable to transmit compression force when the gap is open; - an activation knob rotatable for opening the gap and activating the biasing member; and - a force-selector knob threadably connected to the threaded portion of the first connector member, the force-selector knob rotatable for engaging a pin, the pin transverse to the slot and movable along the slot for opening the gap.