2003. Incidence of Knee Pain and Symptomatic Knee Osteoarthritis among Veteran Traumatic Amputees and Nonamputees
DC Norvell, Puget Sound Health Care System and Graduate Student, University of Washington, N Weiss, University of Washington, J Czerniecki, Puget Sound Health Care System, GE Reiber, Puget Sound Health Care System, C Maynard, Puget Sound Health Care System

Objectives: The majority of traumatic amputees are successful ambulators. However, most are exposed to long term prosthetic use which may be a risk factor for secondary knee disability.  The extent of knee pain and symptomatic knee osteoarthritis (OA) and its associated functional impact on veteran traumatic amputees compared to veteran nonamputees is not known.

Methods: Potential subjects were male and 40 years of age or older.  mputees were included if they suffered a traumatic unilateral transfemoral or transtibial amputation and had ambulated with a prosthesis for at least 5 years.  mputees and nonamputees were excluded if they had sustained a significant knee injury or had a rheumatic disease. Data was collected by telephone interview.

Results: There were 61 amputees and 91nonamputees in this study and the average ages of the two groups was 63.1 plus or minus 11.9 and 65.2 plus or minus 11.4, respectively.  Amputees were on average 32.8 plus or minus 16.5 years since their last lower limb surgery.  Cases of knee pain and symptomatic knee OA were divided by the number of eligible subjects per group to determine the cumulative incidence. The cumulative incidence of knee pain among amputees and nonamputees was 39.3% and 18.7%, respectively. The cumulative incidence of symptomatic knee OA among amputees and nonamputees was 14.8% and 9.9%, respectively.  The age and body mass index (BMI)-adjusted relative risk of knee pain and symptomatic knee OA among amputees, compared with nonamputees, was 2.4 (95% CI 1.4 to 4.1) and 1.7 (95% CI 0.7 to 4.3), respectively. There were no statistically significant (p>0.05) differences in the Chronic Pain Grade (CPG) pain intensity items, number of disability days, or hierarchical grades of the CPG classification comparing amputees to nonamputees. However, nonamputees reported significantly higher interference with recreation (mean score: 6.8 plus or minus 4.0 vs. 2.5 plus or minus 3.4; p=0.001) than amputees on the 0-10 CPG scale.

Conclusions: This study suggests that veterans with a prior traumatic amputation were more than twice as likely to develop knee pain in the residual limb compared to nonamputees.

Impact: Based on these findings, future studies are needed to explore and address the gait abnormalities induced by prosthetic use.