Knee Joint Replacement, Despite a Fracture and Osteoporosis
The six women in this report had much in common. They'd all fallen and broken the bone just above or just below the knee. All had osteoporosis and decreased bone mass called osteopenia. All were over 70 years of age. They all had severe arthritis and other health problems such as heart or lung disease.
Why were they the subjects of this study? Because they were all treated for the fracture with a brand new knee joint. And the results were exceptional. Older adults with these kinds of injuries often have many problems in treatment. The fracture doesn't always heal, and pins to hold the bone together sometimes come loose. A total knee replacement (TKR) isn't usually used because of the weak bone structure.
This group of doctors from the University of Vienna Medical School in Austria decided to try something new. Each woman was given a TKR. A special kind of implant was used for five of the six women. It's called a constrained prosthesis. The posterior ligament inside the knee is saved so the implant has less motion than the unconstrained model. Only one patient received an unconstrained implant. All implants were cemented in place.
The authors report good results for all six women. Each of the women could get up the next day and put weight on the leg right away. Within six months they were pain free and could walk as far as their general health allowed. One patient could walk unaided, but the rest used a cane or a walker. Results were just as good up to three years later.
The results of this study suggest TKR is an option in treating fractures around the knee. Patients must be selected carefully, but TKR is possible even with severe health problems.
Thomas Nau, MD, et al. Primary Total Knee Arthroplasty for Periarticular Fractures. In The Journal of Arthroplasty. December 2003. Vol. 18. No. 8. Pp. 968-971.