Page 214 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Chapter 11
junctions, and allograft resorption on the long term28, 31. Furthermore, structural allograft reconstructions are technically demanding as it is often di cult to obtain an adequate t between the allograft and host bone32, 33. In addition, in some countries, widespread use of allografts might be restricted by limited availability and concerns about transmission of infectious diseases33.
Endoprosthetic devices, on the other hand, allow for relatively easy, quick and durable reconstruction10. The rst endoprosthesis that was commonly used for reconstruction of pelvic tumor defects was the saddle prosthesis17, 34, 35. This implant requires the surgeon to create a notch in the remnant iliac wing, to match the curved shape of the saddle prosthesis36. The saddle prosthesis lacks modularity and may require additional resection of the iliac wing to be implanted37, 38.
Various authors consider stemmed implants the state of the art for periacetabular reconstruction39-41. Others prefer to use custom-made or hemipelvic prostheses42-44. Although comparative studies between stemmed and hemipelvic implants are lacking, hemipelvic implants have a number of inherent disadvantages. Most importantly, they lack the possibility of intraoperative adjustment. This may cause problems when greater resection is needed than was anticipated preoperatively45. In addition, custom-made implants may cause delay in treatment and are costly to manufacture46, 47.
Although recent developments have greatly increased the possibilities and clinical outcome after treatment for pelvic bone sarcoma, these large reconstructions are still fraught with complications.
1.1 Soft-tissue failure and instability
Resections of pelvic bone tumors often require extensive surgical approaches, and frequently leave large dead spaces and poorly vascularized soft-tissue aps, resulting in a substantial risk of wound dehiscence and deep infection14, 48-50. The true incidence of wound dehiscence is however uncertain because many authors fail to mention super cial wound problems21, 39, 51. Apart from the risk of wound problems and deep infection, the extensive soft tissue resections also lead to poor muscular support around the neo-joint, and thus contribute to the high risk of prosthetic dislocation, especially for saddle prostheses34, 38, 50. In our retrospective study on periacetabular reconstruction with the (monobloc) pedestal cup endoprosthesis, we found that 16% of patients had experienced recurrent dislocations during follow-up10.
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