Where Are We Now?

The management of large periacetabular defects after oncologic resections has always been one of the most technically demanding surgical interventions in orthopaedics. The appropriate treatment options generally include either amputation, internal hemipelvectomy, allograft composite reconstruction, or endoprosthetic replacement. However, each is, in its own way, a high-risk intervention.

Bus and colleagues retrospectively studied a novel modular prosthesis with pelvic and hydroxyapatite-coated femoral fixation (LUMiC® prosthesis [implantcast, Buxtehude, Germany]) with a minimum multicenter followup of 24 months. The authors found that while dislocations were a common cause of failure (recurrent dislocations occurred in 9%, or four of 47 patients), a dual-mobility articulation lowered the risk of dislocation. And although loosening was found to be consistent with other published studies on other novel methods of pelvic endoprosthetic reconstruction [2, 4], infection was the most common complication reported. The authors did note that the majority of the infections were successfully managed with débridement and antibiotics.

Where Do We Need To Go?

Although this study certainly adds promise to the armamentarium of prosthetic pelvic reconstruction options, it remains unclear whether cemented or uncemented femoral fixation differs in terms of overall durability, and whether silver coating of the acetabulum leads to fewer infections.

How Do We Get There?

A larger study size with long-term followup will help to elucidate these issues. Additionally, the authors may consider utilizing a functional outcome measurement tool such as the Musculoskeletal Tumor Society Score, the Toronto Extremity Salvage Score, or the Barthel Index to determine if this prosthesis adds functional benefits compared to historical interventions such as external hemipelvectomy and internal hemipelvectomy with or without reconstruction. Long-term functional outcomes are similar between patients who underwent external hemipelvectomy and complex limb sparing endoprosthetic reconstruction. In today’s cost conscious healthcare environment, answers to such questions may become increasingly important [1, 3, 5].

Lastly, as is noted by the authors, periacetabular reconstruction surgery has a substantial learning curve and it is entirely plausible that the benefits of this intervention might only be achievable in experienced hands. Future studies should attempt to identify differences in durability and functional outcomes between patients with primary bone sarcomas and other oncologic diagnoses such as metastatic carcinoma where age, comorbidities, and medical treatment may differ considerably.