Induced-Membrane Reconstruction after Calcaneum's Ewing Sarcoma in Children: a Report of Three Cases

Calcaneus's Ewing sarcoma is a rare location with a poor prognosis and remains challenging for tumor surgery. We present 3 cases of calcaneus resection for Ewing sarcoma in children and its reconstruction managed by induced-membrane technique. To our knowledge, this technique has never been published for hindfoot's tumor management. Three children (aged from 9 to 14 years) had partial or total resection of calcaneus initially replaced by a cement spacer. The second step consisted of removing the cement and filling the membrane cavity with autograft taken from the ipsilateral iliac crest, potentially combined with bone substitute. In the meantime, children received chemotherapy and possibly radiotherapy according to the Euro E.W.I.N.G. 99 protocol. It was possible to optimize bone formation as we carried out the bone grafting procedure sometime after the treatments. In one case, the evolution was marked by local septic complication, 9 months after resection, and by tumor recurrence in presacral soft tissues treated with radiotherapy and chemotherapy. Partial weightbearing was allowed after 6 weeks of cast, under the protection of a splint. Graft consolidation was achieved at a median of 3.2 months (3-3.5) for all. After a median follow-up of 9 years (5-13), all preserved their limb and were considered in remission. The 3 children reached adulthood, with a median age of 21 years (19-24.8). At last follow-up, median Musculoskeletal Tumor Score was 73% (63-87), and median American Orthopaedic Foot and Ankle Society hind foot score was 78 (72-87).