title: Soft-tissue optimization of limb salvage with knee endoprosthesis: the 10-year experience at the Children's Hospital of Philadelphia.
abstract: OBJECTIVE
  Limb salvage in bone sarcomas requires resection and joint and soft-tissue reconstruction. Suboptimal coverage can lead to prosthesis infection, subsequent hardware exposure, or loss with eventual amputation. In the pediatric sarcoma population, it is essential to not only have viable soft-tissue coverage but one that minimizes donor site morbidity and maximizes function and growth over time.
  
  
  METHODS
  This is a retrospective review of all sarcoma patients with primary gastrocnemius and soleus muscle flap coverage of modular knee endoprosthesis over the 10-year period between 1997 and 2007. All patients had resection of the skin at the tibial biopsy site prior to their primary tumor resection surgery. After resection of the knee joint and proximal tibia with clear margins, the bony defect was reconstructed with an endoprosthesis. The gastrocnemius and soleus muscles were then independently rotated to cover the prosthesis and the patellar tendon.
  
  
  RESULTS
  Eleven patients (10 male, 1 female) with an average age of 13 years (range, 10-17) underwent resection of proximal tibia. Pathology included osteosarcoma in 9 patients, Ewing in 1, and spindle cell sarcoma in 1 patient. All patients had endoprosthetic coverage by gastrocnemius and soleus flaps; 4 patients had additional split-thickness skin graft over the gastrocnemius. The average level of tibial resection was 16.5 cm distal to the articular surface of the proximal tibia. Mean soft-tissue mass volume resected with bone was 157 cm. There was one flap failure that was reconstructed with a rectus abdominis free flap. Average follow-up was 32 months (range, 8-92 months). Two patients succumbed to metastatic disease. In this series, there was no limb loss or hardware exposure or infection. All patients achieved independent ambulation. Functionally, patients were evaluated based on the Musculoskeletal Tumor Society scale. The average score was 29 (out of a perfect score of 30). Two patients had transient foot drop that resolved with ankle foot orthosis use. Anticipated leg length discrepancy was detected in 3 patients who underwent opposite limb epiphysiodesis with ultimate limb equalization.
  
  
  CONCLUSIONS
  Soft-tissue reconstruction with gastrocnemius and soleus muscle flap coverage decreases wound complications and hardware exposure while maintaining function in the pediatric population.
authors: Division of Plastic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
authors: Theresa Y
authors: TY
authors: Wang
authors: John P
authors: JP
authors: Dormans
authors: Benjamin
authors: B
authors: Chang
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000601:surgery*; D002648:Child; D005260:Female; D006776:Hospitals, Pediatric; D006801:Humans; D007720:Knee Prosthesis; D023821:Limb Salvage / Q000379:methods*; D008297:Male; D015143:Philadelphia; D012189:Retrospective Studies; D012509:Sarcoma / Q000601:surgery*; D013524:Surgical Flaps; D013997:Time Factors