Ceramic-on-Poly Femoral Head Fractures: What's Going On?

Abstract

As outlined in our January 16, 2013, editorial , “The Case Report Redefined with JBJS Case Connector ,” one important role of JBJS Case Connector is to alert the orthopaedic community about a potentially problematic device or therapy. When two or more such cases with similar mechanisms appear, we will identify the procedure or implant as a “watchable” intervention. While this system is not statistically conclusive and may or may not be supported by other published case reports or registry data, the intention is to sharpen the focus of clinicians on the potential for similar problems and thereby enhance clinical outcomes and patient safety. The “Watch” designation may also encourage others to report related difficulties and enlist the orthopaedic community to either demonstrate that these are isolated, unrelated cases or sharpen the focus further on rigorously evaluating the intervention. Where appropriate, we may identify brand, model, or implant-lot specifics. In total hip arthroplasty (THA), a fractured ceramic head is a catastrophic but thankfully very rare event. Most case reports of ceramic head fractures involve ceramic-on-ceramic articulations, but this “Watch” describes three cases of femoral head fractures involving ceramic-on-polyethylene bearings. Moreover, the fractures occurred in association with little or no postsurgical trauma. Ceramic hip components are often chosen for younger patients in an effort to minimize long-term wear. On the downside, unlike metal, ceramic components can fracture. Ceramic femoral head fractures arise from four main factors: trauma; material or manufacturing defects; non-compatible, damaged, or contaminated femoral stem/head taper connections; or other suboptimal surgical techniques. The ceramics industry has a more-than-forty-year track record of continuous improvement in hip-component manufacturing. CeramTec, the main U.S. player in this arena, first introduced ceramic hip components in 1974; those first-generation femoral heads had a fracture rate of 0.026%. By 2003, when CeramTec introduced its fourth-generation BIOLOX …