Risk of Knee Osteoarthritis Increases in Patients after Amputation

Patients who’ve lost a leg may be at risk for increased arthritis in the other knee. The reason for this is the way they change their walking pattern. Using a prosthetic device on the amputated leg changes the person’s stride length and walking speed. It also shifts more of the load to the normal leg (knee).

Men over the age of 40 from the Veterans Administration (VA) were involved in this study. One group had lost the leg by some kind of trauma. It was amputated either below the knee through the lower leg bone (transtibial) or above the knee (transfemoral). The other group didn’t have an amputation at all. The amputee group had been walking with a prosthesis for at least five years.

Patients in both groups were asked questions about knee pain, stiffness, and crepitus. Crepitus is the crunching sound or feeling heard or felt during knee motion. Pain intensity and interference with daily activities was recorded. Age and body weight were taken into consideration. Data was viewed to see if the level of the amputation made a difference.

Here’s what they found:

  • Amputees were less active and more likely to be overweight.
  • Heavier amputees had more knee pain than anyone else.
  • Transfemoral amputees had much more knee pain than transtibial amputees.
  • Nonamputees had the least amount of knee pain.
  • Amputees were more likely to have knee pain from osteoarthritis than nonamputees.

    The authors conclude that men with amputations are twice as likely to have pain in the other leg compared to men without amputation. Over time the increased load from shifting weight from the disabled leg to the normal leg adds up. Early treatment may help reduce these stresses.