Adult Reconstruction – Joint Replacements

Mechanobiology of the Cement-Bone Interface

(Inv: Mann, Allen) When cemented implants loosen, a fibrous tissue layer often results at the cement-bone interface. While mechanical overloading is thought to play a role in this process, the actual relationship between mechanical loading and biologic response is not known. The goals of this study are to elucidate the mechanical and biologic contributions to implant loosening.

Bone Cement Studies

(Inv: Mann, Race, Allen) We are investigating the mechanical characteristics of and biologic response to a number of bone cements used in orthopedic practice. While PMMA based bone cements have been used for over four decades, the optimal conditions in terms of surgical technique, handling characteristics, and long-term performance have not been determined. Laboratory fatigue studies are performed using realistic conditions to determine how these complex systems perform. (National Institutes of Health, Corporate )

Pharmacological Strategies for Implant Osteolysis

(Inv: Allen) Aseptic implant loosening occurs when the interface between an implant and the surrounding bone is damaged. Retrieval studies have shown that inflammatory responses to particulate wear debris leads to the bone destruction (osteolysis) that triggers loosening. The purpose of this study is to use an established rat model of implant osteolysis to screen candidate drug therapies for implant osteolysis (Comparative Bone Biology Fund, SUNY Upstate Medical University).

Preclinical Evaluation of Novel Biomaterials

(Inv: Allen, Ordway, Mann, Gilbert (SU)) Ongoing preclinical studies are being conducted on a number of new implant materials, including novel titanium alloys, resorbable bone graft substitutes for spine fusion, and a liquid-liquid bone cement for total joint replacement. (Corporate sponsors)

A Comparison of Effectiveness of Antibiotic Bone Cements with Tobramycin Formulations

(Inv. Webster, Spadaro). This study is to examine the effectiveness of new formulations of the antibiotic, Tobramycin, added to methyl-methacrylate bone cements for in joint surgery and treatment for bone lesions. The study will be performed in vitro looking at elution rates and antibacterial efficiency. (Pharma-Tek, Inc.)

Fatigue Crack Morphology in Cemented Hips

(Inv: Race, Mann) We have developed an automated serial grinding and imaging system to study the three-dimensional architecture of micro-cracks in the cement mantle surrounding a femoral stem. This technique has been used to study fatigue damage in vitro and will be applied next to post-mortem retrievals. Such detailed mapping of fatigue damage will provide insights into failure mechanisms, which will lead to improved designs of femoral stem. (National Institutes of Health)

Pre-Clinical Testing of Cemented Femoral Stems

(Inv: Race, Mann) A novel design of femoral stem is required to meet certain fatigue failure standards, but there is no standard test of the stem/cement/femur construct. Cemented stems are not yet optimized and novel designs have sometimes had surprisingly poor clinical results, so a robust pre-clinical test is required.

Cyclic Testing of Total Knee Replacements

(Inv: Werner) Long and short term fatigue testing of total knee replacements implanted into cadaver knees is being conducted to assess their potential for loosening and for changes in joint kinematics (Corporate Funding).