[01] Ronald Hugate, The Denver Clinic for Extremities at Risk at Presbyterian/St. Luke’s Medical Center, Denver, Colorado, USA. [02] Rhonda Clarke, Zimmer Biologics, Austin, Texas, USA. [03] Tim Hoeman, Product Development and Global Brand Management, Zimmer Trabecular Metal Technology, Parsippany, New Jersey, USA. [04] Andrea Friedman, Zimmer Trabecular Metal Technology, Parsippany, New Jersey, USA.

Porous tantalum has long been used in orthopedics for enhanced bone in-growth. The purpose was to evaluate soft tissue integration into transcutaneous porous tantalum implants. Eighteen porous tantalum and four solid titanium implants were placed within and passed through the subcutaneous tissues of swine. They were harvested after six weeks and examined microscopically to evaluate epidermal contact, soft tissue penetration into and onto the implant, and inflammation. Fifteen of sixteen porous implants demonstrated both soft tissue and vascular tissue penetration. Nine of sixteen porous implants demonstrated epidermal contact with the transcutaneous portion of the implant. A score of 0-4 was used to describe tissue ingrowth (0=none and 4=100%). Soft tissue penetration score averaged 1.25 at the post and 2.63 at the base of the implant. Vascular tissue penetration score averaged 1.0 at the post and 2.63 at the base. Inflammation was evaluated and scored from 0-4 (0=none and 4=marked inflammation). Acute inflammation was present in six of sixteen porous implants with an average score of 1.88 at the transcutaneous post and 0.81 at the subcutaneous implant base. Chronic inflammation was present in every porous implant with a mean score of 1.5 at the post and 1.56 at the base. Three of the four solid titanium implants extruded during the study. The one surviving implant did not demonstrate any epidermal contact on the implant post or tissue ingrowth with chronic and acute inflammation scores of 2 at the base. Porous tantalum transcutaneous implants experienced epidermal, soft tissue, and vascularized tissue adhesion and integration with minimal inflammation. This finding may help prevent deep infection in transcutaneous implants.

Transcutaneous Implants, Highly Porous Tantalum, Implant Infection Prevention

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