Lower Limb Amputation in Patients with Vascular Disease

Sammanfattning: The current prevalence of persons amputated at transmetatarsal level or higher in Sweden can be estimated to be between 5000 and 5500 persons (approx. 0.06 % of the population). The majority of these are patients with vascular disease (≈ 80%). In Sweden between 1000 and1100 new amputees can be expect every year. Less than 5% of all amputations will be related to causes other than vascular disease.
Lower limb amputation (LEA) in patients with vascular disease may not only be highly disabling but also costly in hospital management. The incidence differs between countries due to age structure of the population, prevalence of vascular disease and the prevalence of diabetes. In Paper I we prospectively evaluated LLA performed at transmetatarsal level or higher during 10 years. The overall incidence of initial unilateral amputation in the diabetic population was eight times higher compared with that in the nondiabetic population (195 vs. 23 per 100,000 person-years). The incidence of contralateral amputation among diabetic amputees was 17 and among the nondiabetic amputees 13 per 100 amputee-years. The most frequent contralateral amputation level among the diabetic and nondiabetic patients was trans-tibial. The incidence of re-amputation among the diabetic amputees was 19 and among the nondiabetic amputees 14 per 100 amputee-years. The most frequent re-amputation level among diabetic patients was trans-tibial and among nondiabetic patients was trans-femoral.
The 1-year mortality rate, adjusted for age and gender, did not differ significantly between the two groups.
In Paper II we introduce a Swedish version of the Locomotor Capabilities Index (LCI) outcome instrument and evaluate its reliability and validity. Following the process of translation and cultural adaptation, the Swedish version of the LCI was found to be reliable and valid instrument that can provide a standardized measure of amputee-centered outcomes.
In Paper III we tested two different dressings after trans-tibial amputation, the conventional rigid dressing of plaster of Paris and a new vacuum-formed removable rigid dressing. The primary outcome measure was time to prosthetic fitting while the secondary outcomes included function with the prosthesis 3 months after amputation measured with the LCI and the Timed “Up and Go” (TUG) test. Twenty-seven consecutive patients were included and prosthetic fitting was achieved in 23 patients (mean age 76 years). The same postoperative treatment and rehabilitation was applied in both groups. To minimize the possible influence of using different types of prostheses in measuring functional outcome ICEX prosthetic sockets were used in all patients. The new vacuum-formed removable rigid dressing appear to yield similar results regarding wound healing, time to prosthetic fitting and function, rate of socket changes during the first year or return to previous dwelling when compared with conventional plaster of Paris rigid dressing.
In Paper IV we prospectively evaluated the outcome of a standardized surgical and rehabilitation program in trans-tibial amputation in a large consecutive and population-based series of 219 patients. We analyzed the outcome regarding rate of prosthetic fitting, walking ability and mortality. A circular, plaster of Paris rigid dressing was applied by the surgeon in the operating room. This rigid dressing was removed after 5 to 7 days and compression treatment with a silicone liner was started. Ambulation with an ischial weight bearing training prosthesis was started when the plaster of Paris dressing was removed, with no load on the residual limb. A prosthetic socket that is cast and made directly on the residual limb using pressure casting technique, resulting in a definitive socket was used. Functioning was defined as good if the patient wore the prosthesis daily and was able to walk alone or with assistance outdoors or alone indoors. Functioning was defined as poor if the patient did not wear the prosthesis daily and was unable to walk indoors without assistance or used a wheelchair most or all the time or did not receive prosthesis. All prostheses were produced and delivered on the same visit to the prosthetic workshop. More than half of all amputees could be fitted with a prosthesis after a median time of six weeks and almost two-thirds have good function 3 months after amputation and the functional status remained unchanged at 1 year. Poor functional outcomes correlated with delayed prosthetic fitting and not living independently before amputation. Of the patients who could walk with or without an aid prior to the amputation and who survived at least 90 days after amputation, more than 80% could be provided with a prosthesis with 68% achieving good function. These patients can expect a median survival of approximately 3.5 years.