HINTS ON THE TREATMENT OF MACRODYSTROPHIA LIPOMATOSA

Macrodystrophia lipomatosa is a rare disease that may lead to lower limb lenght discrepancy.

Lower limb lenght discrepancies are usually addressed through a surgical procedure called “epiphysiodesis”. Epiphysiodesis consists in fixing bone ends to the central part of the bone by the use of osteosynthesis. The aim is to stop the activity of the growth plate lying in the middle.

Various types of metallic devices can be used for the osteosynthesis, which can be performed “open air” (opening the leg) or by means of endoscopy. Two major interventions on macrodystrophia lipomatosa patients are described in the literature: staple epiphysiodesis according to Blount technique and PETS (percutaneous epiphysiodesis using transphyseal screws).

Two big reviews analysing large pools of patients treated by either the first or the second intervention have been published (respectively: PMID 19797579 and PMID 17717460).

According to authors, proximal tibial and combined distal femoral and proximal tibial staple epiphysiodeses, even if done well technically, lead to clinically relevant shifts in the mechanical axis of the lower extremity more than half of the time. Distal femoral staple epiphysiodesis may still be a safe option for the treatment of limb-length discrepancy. In summary: caution is adviced when utilizing proximal tibial staple epiphysiodesis to treat limb-length inequality. Moreover, it’s of note that, although referring to old cases published in the seventies, adverse effects of the staple epiphysiodesis intervention such as reactions to metal, hypercorrection (excessive correction of the defect), premature growth plate closure, peroneal nerve paresis, knee joint laxity and infections have been reported.

Conversely, PETS reported complications were minor and were related to incorrect placement of screws or minor hardware irritation. According to author, percutaneous screw epiphysiodesis is a reliable, minimally invasive method with reliable results in both length and angular correction, with minimal morbidity, and with an acceptable complication rate.

In our opinion, due to the rarity of the condition and the possible complexity of the intervention, it might be useful to ask more than one surgeon for counselling.

References

Gorman TM, Vanderwerff R, Pond M, MacWilliams B, Santora SD.Mechanical axis following staple epiphysiodesis for limb-length inequality. J Bone Joint Surg Am. 2009 Oct;91(10):2430-9. PMID 19797579

Khoury JG, Tavares JO, McConnell S, Zeiders G, Sanders JO. Results of screw epiphysiodesis for the treatment of limb length discrepancy and angular deformity. J Pediatr Orthop. 2007 Sep;27(6):623-8. PMID 17717460