Bone non-union and the Ilizarov frame: when limb reconstruction still works骨不连与 Ilizarov 外固定架：什么时候肢体重建还有效

Why a fracture stops healing

Bone unites when three things are present: blood supply, stability and contact. Remove any one and the fracture becomes a non-union — the ends round off, a false joint forms, and more time alone will not fix it.

The usual causes:

• Infection — the most common reason a plate fails. Hardware sitting in biofilm will never be sealed over by bone.
• Instability — a plate too short, screws that loosened, a nail that never achieved rotational control.
• Biological failure — the periosteum stripped at the first operation, or a segment of bone lost to open injury.
• Systemic factors — smoking, diabetes, long-term steroids, poor nutrition.

That list matters because the treatment differs. Infected non-union needs the hardware out and the bed debrided before anything can be rebuilt. An aseptic non-union with good soft tissue may only need a stronger construct.

What circular fixation does differently

An Ilizarov-type frame is a set of rings connected by threaded rods, fixed to the bone with thin wires and half-pins. It does two jobs that plates cannot:

1. It holds bone without touching the fracture site. No foreign body at the non-union means infection has nowhere to hide, and the blood supply is not disturbed again.
2. It can move bone. Cut the bone away from the non-union (a corticotomy), then lengthen by 1 mm per day and new bone fills the gap behind the moving segment. This is distraction osteogenesis — the same biology that lengthens a child's leg, put to work deliberately.

For a 4 cm gap, that is roughly 40 days of lengthening plus a consolidation period of two to three times as long. Frame time for a tibial reconstruction is commonly four to eight months; a complex infected case with a large defect can run longer.

The honest costs

• Pins get infected. Superficial pin-site infection is common and usually managed with cleaning and oral antibiotics. Deep infection is uncommon but real.
• It is uncomfortable. Muscle tethering around wires limits movement; most patients need physiotherapy throughout, not after.
• It dominates your year. Showering, sleeping, clothing and work all change. Patients who do best are the ones who plan for that from the start rather than hoping it will be quick.
• It can fail. Non-union of the regenerate, hardware breakage and joint stiffness are known complications. A surgeon who quotes you a single success rate for all comers is not giving you your number.

When reconstruction is the wrong answer

• The limb has no usable distal function and no prospect of it
• Vascular disease makes prolonged fixation unsafe
• The patient cannot participate in the follow-up this treatment demands
• The bone loss is so large that reconstruction would take years for a worse result than a prosthesis

Saying this out loud is part of a proper consultation. A plan that ignores it is not a plan.

What to send for an assessment

X-rays in two planes showing the whole bone (not just the fracture), any CT, wound photographs if there is a sinus, the operative reports from previous surgeries, and a CRP/ESR if infection has ever been suspected. With that file, a reconstruction surgeon can tell you within days whether the case is a frame case, a bone-graft case, or a "stop operating" case.