Page 213 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

abdominal complaints and, because they are located deep in the body, are often large at the time of diagnosis13. As a result, they are di cult to access surgically and often demonstrate close proximity to major neurovascular, urinary, and intestinal and reproductive organ structures. Therefore, it can be challenging to obtain an adequate resection margin14. Nevertheless, limb-salvaging internal hemipelvectomies are nowadays the standard of care for patients with a pelvic bone tumor, if a clear margin can be achieved2.
Internal hemipelvectomy gained favor over hindquarter amputation because of obvious cosmetic, psychological and functional advantages2, 15, 16. According to Enneking’s classi cation of pelvic resections12, a type 1 or type 3 internal hemipelvectomy (i.e., isolated resection of the ilium or pubis) does not compromise the anatomic weight-bearing axis and therefore, these resections generally do not necessitate reconstruction17, 18. However, if the periacetabular bone has to be resected (type 2 internal hemipelvectomy) and femorosacral continuity is disrupted, a particular reconstructive challenge arises19.
After a type 2 internal hemipelvectomy, one strategy is to leave the defect alone, producing a ail hip (“super Girdlestone”)20, 21. This however results in instability of the iliofemoral joint and severe shortening of the a ected side. Others prefer to perform an iliofemoral arthrodesis or pseudarthrosis, either to obtain solid fusion or as primary pseudarthrosis19, 22. These procedures may provide moderate but durable long-term functional results22. On the other hand, failure to obtain fusion occurs in up to 50% of primary pseudarthroses, potentially resulting in a painful reconstruction with poor function19. Another alternative is transposition of the hip, a procedure which serves to produce a neo-joint at the level of iliac resection rather than reconstruct the weight-bearing axis or acetabulum23. Although transposition of the hip generally results in reasonable and predictable functional outcome21, 23, 24, it may cause signi cant shortening of the a ected limb10. This may be corrected during a secondary lengthening procedure; however, these operations are associated with a signi cant risk of major complications, especially in inexperienced hands25.
Other techniques aim to restore the native situation as much as possible. Allografts, either as a structural pelvic allograft or as part of an allograft-prosthetic composite reconstruction, have been commonly used15, 26-30. Acceptable long-term results have been reported29, 30, although many surgeons prefer to avoid the use of allografts because they are considered to be associated with high rates of infection and mechanical complications, including graft fracture, nonunion of allograft-host
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General discussion
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