by Elizabeth Hofheinz, M.P.H., M.Ed.
Do we really know how much a knee fracture elevates the risk of total knee arthroplasty (TKA)? And what are the risk factors involved? That is what a team from the U.S. and Denmark set out to determine. Their work, “Knee Fracture Increases TKA Risk After Initial Fracture Treatment and Throughout Life,” appears in the September 2020 edition of Clinical Orthopaedics and Related Research.
Veronique Vestergaard, M.D., Ph.D., is an orthopaedic surgery resident with the Harris Orthopaedics Laboratory at Massachusetts General Hospital, as well as Copenhagen University Hospital Hvidovre in Denmark. She told OSN, “In some cases, a knee fracture (involving the distal femur, patella, and/or proximal tibia) may lead to posttraumatic osteoarthritis, and subsequent secondary TKA. Secondary TKA for posttraumatic osteoarthritis is, in terms of level of procedure complexity, often compared to that of a revision TKA with extensive soft tissue damage.”
Fundamentally, it’s all about the patient-physician discussion
“We need more knowledge on the treatment burden as well as absolute risk estimates of and risk factors for TKA in knee fracture patients compared to those of the general population without a knee fracture, in order to properly counsel patients on their outcomes and risk of TKA following knee fracture.”
The authors used a nationwide 20-year, matched-case comparison cohort study of prospectively collected data from the Danish National Patient Registry. They wrote, “Each patient with a knee fracture was matched (by sex and age) to five people without knee fractures from the general Danish population on the date the knee fracture patient’s knee fracture was registered (population controls). Patients with knee fractures and people in the population control group were followed from the date the knee fracture patient’s knee fracture was registered to the date of TKA, amputation, knee fusion, emigration, death, or end of follow-up in April 2018…”
Elevated risk…and exact risk factors are?
Dr. Vestergaard: “Knee fracture patients have a 3.7 times higher risk of undergoing TKA in the first three years after knee fracture, compared to the control population. After three years, and during their lifetimes, the risk remains elevated at 1.6 times. Risk factors additive of that risk are: being diagnosed with primary knee osteoarthritis, having surgical treatment for knee fracture, being treated with external fixation for knee fracture, having a proximal tibia fracture, and having a distal femur fracture.”
“By researching risk estimates of and risk factors for TKA in knee fracture patients, we hope that orthopedic surgeons will better be able to counsel patients on their expected outcomes after knee fracture as well as any other risk factors for TKA which are additive to that risk. The results from this study will be used in future research in further exploring knee fracture patients’ TKA risk based on patient-, fracture-, and treatment-related factors, thus helping physicians plan the right treatment for the right patient at the right time.”