Reconstruction After Hemipelvectomy With the Ice-Cream Cone Prosthesis: What Are the Short-term Clinical Results?

BACKGROUND: Reconstruction after internal hemipelvectomy resection likely provides better function than hindquarter amputation. However, many reconstruction methods have been used, complications with these approaches are common, and function often is poor; because of these issues, it seems important to investigate alternative implants and surgical techniques. QUESTIONS/PURPOSES: The purposes of this study were (1) to identify the frequency of surgical site complications and infection associated with the use of the Ice-Cream Cone prosthesis for reconstruction after hemipelvectomy for oncological indications; (2) to evaluate the Musculoskeletal Tumor Society (MSTS) outcomes scores in a small group of patients treated with this implant in the short term; and (3) to quantify the surgical margins and frequency of local recurrence in the short term in this group of patients.
METHODS: Between 2008 and 2013, one center performed a total of 27 internal hemipelvectomies for oncological indications. Of those, 23 (85%) were treated with reconstruction. Our general indications for reconstruction were patients whose pelvic stability was affected by the resection and whose general condition was sufficiently strong to tolerate the reconstructive procedure. Of those patients undergoing reconstruction, 14 (61%) were treated with an Ice-Cream Cone-style implant (Coned®; Stanmore Worldwide Ltd, Elstree, UK; and Socincer® custom-made implant for the pelvis, Gijón, Spain), whereas nine others were treated with other implants or allografts. The indications during this time for using the Ice-Cream Cone implant were pelvic tumors affecting the periacetabular area without iliac wing involvement. Of those 14, 10 were available for followup at a minimum of 2 years (median, 3 years; range, 2-5 years) unless a study endpoint (wound complication, infection, or local recurrence) was observed earlier. Study endpoints were ascertained by chart review performed by one of the authors.
RESULTS: Surgical site complications occurred in five patients. Of those, two developed superficial infections with necrosis, two developed deep infections, and one patient developed wound necrosis without apparent infection. No prostheses were removed as a result of these complications [corrected]. Median MSTS score was 19 out of 30 when 0 is the worst possible result and 30 a perfect function and emotional status. Five of seven primary tumors had wide margin surgery and three of seven developed local recurrences by the end of the followup.
CONCLUSIONS: Pelvic reconstruction with the Ice-Cream Cone prosthesis yielded fair functional results at short-term followup. Longer term surveillance is called for to see whether this implant will represent an improvement over available reconstructive alternatives such as allograft, custom-made implants, and saddle prostheses. We are cautiously optimistic and continue to use this implant when we need to reconstruct the periacetabular area in patients without Enneking Zone 1 involvement. LEVEL OF EVIDENCE: Level IV, therapeutic study.