Survival of the Insignia Stem in Total Hip Arthroplasty

Mid-term Survival of the Insignia Stem in Primary Total Hip Arthroplasty

The investigators primary objective of this study is to evaluate radiographic fit and fill of the Insignia stem and identify risk factors for aseptic failure. The investigators hypotheses being tested is: the newly designed Insignia stem demonstrates acceptable radiographic fit and fill by reviewing radiolucent lines <2mm.

Total hip arthroplasty is one of the most functionally restorative procedures in modern medicine. Since its introduction in the mid twentieth century significant advancements in implant materials have occurred. There is debate on the design of the femoral stem in total hip arthroplasty. The use of uncemented, Hydroxyapatite (HA)-coated femoral stems have been shown to be reliable and are commonly used. One such implant is the Insignia™ Hip Stem (Stryker, Kalamazoo, MI, USA).

The Insignia™ Hip Stem is a collared stem that features a plasma-sprayed Hydroxyapatite (HA) coating over plasma-sprayed titanium in the proximal region and a plasma-sprayed HA coating over grit blast in the distal region and collar underside. Unfortunately, with it's novelty comes a lack of clinical follow-up and evaluation. As such, the investigators purpose of this study is to evaluate the early radiographic of the Insignia™ Hip Stem.

Inclusion Criteria:

• Patients age ≥18
• Patients planning on undergoing primary total hip arthroplasty that will likely receive the Insignia stem and associated Stryker Acetabular Component.
• Preoperative diagnosis of osteoarthritis
• Patients willing and able to comply with follow-up requirements
• Patients willing to sign an IRB approved consent and authorization document

Exclusion Criteria:

• Patients with inflammatory or pyogenic arthritis
• Body Mass Index (BMI)>40
• Bone stock that is inadequate for support or fixation of the prosthesis