Successful canine patellar tendon reattachment to porous tantalum

The ability to achieve reattachment of soft tissues, such as tendon, directly onto a prosthetic surface would be of great benefit in case of periarticular bone loss or resection. Bone and potential soft tissue ingrowth using porous tantalum has been observed in prior animal studies. We hypothesized porous tantalum washers used to reattach canine patellar tendon to bone would provide sufficient strength to withstand physiologic loading. We reattached the released patellar tendon to the tibia using two porous tantalum washers in 33 skeletally mature dogs. Force plate analysis of gait, tensile testing of the tendon reconstruction, and histologic analysis of tissue ingrowth into the implants were performed after 3, 6, and 12 weeks' survival. Physiologic weightbearing on the operated leg had normalized 6 weeks after tendon reconstruction surgery. The mechanical strength of the tendon reattachment was 76% of the strength of the native tendon insertion by 6 weeks but did not increase further with time. Fibrous tissue occupied approximately 1/2 of the available space in the porous tantalum washers at all times. Our data suggest tendon healing into a prosthetic material can be achieved using porous tantalum washers with sufficient mechanical strength to withstand physiologic loading.