Intramedullary distraction for lower limb lengthening

Evidence-based recommendations on intramedullary distraction for lower limb lengthening in children, young people and adults. This involves surgically inserting a metal lengthening device in the shorter leg.

# Recommendations
Evidence on the safety and efficacy of intramedullary distraction for lower limb lengthening is limited in quantity and quality. Therefore, this procedure should only be used with special arrangements for clinical governance, consent, and audit or research. Find out what special arrangements mean on the NICE interventional procedures guidance page. This guidance is not intended to cover this procedure for bilateral lower limb lengthening for people with short stature.
Clinicians wanting to do intramedullary distraction for lower limb lengthening should:
Inform the clinical governance leads in their healthcare organisation.
Give patients (and their families and carers as appropriate) clear information to support shared decision making, including NICE's information for the public.
Ensure that patients (and their families and carers as appropriate) understand the procedure's safety and efficacy, and any uncertainties about these.
Audit and review clinical outcomes of all patients having the procedure. The main efficacy and safety outcomes identified in this guidance can be entered into NICE's interventional procedure outcomes audit tool (for use at local discretion).
Discuss the outcomes of the procedure during their annual appraisal to reflect, learn and improve.
Healthcare organisations should:
Ensure systems are in place that support clinicians to collect and report data on outcomes and safety for every patient having this procedure.
Regularly review data on outcomes and safety for this procedure.
Patient selection should be done by a multidisciplinary team that ideally includes physiotherapy and psychological support.
This technically challenging procedure should only be done in specialist centres by surgeons with training and specific experience in limb lengthening techniques.
Report any problems with a medical device using the Medicines and Healthcare products Regulatory Agency's Yellow Card Scheme.
Further research should report details of patient selection, device selection, procedural outcomes, long-term outcomes including quality of life, the need for repeat interventions or surgery, and complication rates. This research could be registry data.# The condition, current treatments and procedure

# The condition
People may have different limb lengths because of trauma or infection (acquired) or, because of hypoplasia or dysplasia of the femur or tibial (congenital). Unequal leg length can cause a limp, limit functional ability and have effect on other joints.

# Current treatments
Lengthening of an abnormally short lower limb can be done after an osteotomy using an external fixation device. This exerts force along the long axis of the bone to induce new bone formation (distraction osteogenesis). The main problems with external fixation include infection of the pin tracts, and external frames that are impractical and aesthetically unacceptable. Once the external fixation is removed, in some people with underlying bone pathology, new bone is augmented by either an internal plate fixation or an intramedullary nail.

# The procedure
Once inserted and fixed, intramedullary distraction systems can be lengthened over time using different techniques. The aim is to lengthen the bone in a controlled manner.
With this procedure, under general anaesthesia, an osteotomy is done while avoiding damage to the periosteum and its blood supply. The adjustable intramedullary nail-like device is then implanted into the intramedullary space. Its proximal and distal sections are fixed to the relevant section of the bone with sterile locking screws. It then exerts a force along the long axis of the bone, which stimulates new bone formation (distraction osteogenesis) in the gap, causing bone lengthening. Over days, weeks or months, sequential distractions are used to produce the target limb length.
Different devices achieve distraction in different ways.
Soon after the procedure, with help from the physiotherapy team, people are able to partially weight bear. After clinical assessment, and when there is radiological evidence of adequate bone consolidation across the gap, full weight bearing is possible. The intramedullary device is usually removed after about 2 years using standard surgical techniques.