What are the functional results and complications from allograft reconstruction after partial hemipelvectomy of the pubis?

BACKGROUND

In patients undergoing hemipelvectomies including resection either of a portion of the pubis or the entire pubis from the symphysis to the lateral margin of the obturator foramen while sparing the hip (so-called Dunham Type III hemipelvectomies), reconstructions typically are not performed given the preserved continuity of the weightbearing axis and the potential complications associated with reconstruction. Allograft reconstruction of the pelvic ring may, however, offer benefits for soft tissue reconstruction of the pelvic floor and hip stability, but little is known about these reconstructions.

QUESTIONS/PURPOSES: (1) What is the postoperative functional status after allograft reconstruction of Type III pelvic defects? (2) What are the rates of hernia, infection, and hip instability?

METHODS

In this case series, we reviewed all patients with Type III pelvic resections (with or without anterior acetabular wall resections) who underwent allograft reconstruction between 2005 and 2013 at one center (N = 14). During the period in question, reconstruction was the general approach used in patients undergoing these resections; during that time, three other patients were treated without reconstruction as a result of either surgeon preference or the patient choosing to not have reconstruction after a discussion of the risks and benefits. Of the 14 patients treated with reconstruction, complete followup was available at a minimum of 1 year in 11 (other than those who died before the end of the first year; median, 19 months; range 16-70 months among those surviving), one was lost to followup before a year, and two others had partial telephone or email followup. Patient demographics, disease status, functional status, and complications were recorded. For a portion of the cohort (four patients) later in the series, we used a novel technique for anterior acetabular wall reconstruction using the concave cartilaginous surface of a proximal fibula allograft; the others received either a long bone (humerus or femur) or hemipelvis graft. Seven patients died of disease; two had local recurrence, and five died of metastatic disease.

RESULTS

All patients remained ambulatory Pain at 12 months after surgery was reported as none in five, mild in two, moderate in two, and severe in one. Operative complications included infection in two, symptomatic hernia in one, hip instability in one, dislocated total hip arthroplasty on the first postoperative day in one, and graft failure in one.

CONCLUSIONS

Allograft reconstruction after Type III pelvic resections can provide functional reconstruction of the pelvic ring, pelvic floor, and, in certain patients with partial anterior acetabular resections, the resected anterior acetabulum. This has implications in preventing the occurrence of hernia and hip instability in this patient population that is classically not reconstructed, although longer-term outcomes in a larger number of patients would help to better delineate this because infection, hernia, hip instability, and graft nonunion still remain concerns with this approach. The most important unanswered question remains whether, on balance, any benefits that may accrue to these patients as the result of reconstruction are offset by a relatively high likelihood of undergoing secondary or revision surgery.