What is limb lengthening?

Cleveland Clinic patient information describes limb lengthening surgery as a procedure that gradually makes an arm or leg bone longer. The surgeon cuts the bone, and the two parts are then slowly drawn apart. New bone forms in the widening gap.

The orthopaedic literature calls this distraction osteogenesis. A published review of limb lengthening describes the principles developed by Gavriil Ilizarov as still the cornerstones of all bone lengthening procedures, whichever hardware is used.

The same review describes lengthening in three phases. How long each lasts is set by the treating team for the individual patient, and this guide does not give durations.

AAOS patient information describes two basic approaches. In external lengthening, a frame outside the leg is connected to the bone with wires, pins or both, and is adjusted to separate the bone segments. In internal lengthening, an expandable metal rod is implanted inside the bone and lengthens gradually. Cleveland Clinic notes that an internal device is not visible outside the body, while the frame and most of an external device sit outside it.

Combined techniques use both: a frame does the lengthening while a nail is already in the bone, or a nail is inserted once lengthening is finished. The published review describes these as developed to shorten the time an external frame has to stay on. LimbAtlas records four techniques — fully internal lengthening, external fixation, lengthening over nail and lengthening and then nailing — and the guide Internal and external limb lengthening explains how they differ.

Limb lengthening has a long history in reconstructive orthopaedics. The published review lists causes of limb shortening such as congenital deficiencies, old poliomyelitis, bone tumours and past trauma, and Cleveland Clinic lists conditions including skeletal dysplasia, congenital femoral deficiency, growth plate fractures and bone infection (osteomyelitis).

Some adults also choose lengthening for aesthetic reasons. A 2025 systematic review describes aesthetic limb lengthening as focusing on increasing limb length for aesthetic purposes, unlike functional lengthening, which addresses limb length differences. The review included 12 studies and concluded that further research with rigorous study designs is needed.

LimbAtlas lists providers that describe reconstructive work, aesthetic lengthening or both. This guide does not suggest whether anyone should consider either; that decision belongs to the person and a qualified clinician.

Lengthening is a gradual process rather than a single operation. AAOS patient information describes both external and internal lengthening as requiring regular follow-up visits and extensive rehabilitation, including physical therapy and home exercise. Cleveland Clinic describes the care team taking X-rays to check new bone growth and adjusting treatment if the bone is forming too quickly or too slowly, and describes the device being removed in a further procedure once the new bone has fully hardened.

Complications are part of the picture. AAOS lists infection at pin or wire sites, joint stiffness and failure of the new bone to consolidate among the possible complications of external lengthening, and the 2025 review reported infections, bone healing problems, joint deformities and implant-related problems across studies of aesthetic lengthening. Which risks apply to a particular person, and how likely they are, is a question for the treating team.

If you are starting to research providers, How to research a limb lengthening provider sets out a structure for comparing them, and Questions to ask a provider lists what to put to each one. Understanding rehabilitation explains how recovery is organised.