Costs and consequences of a prosthesis with an electronically stance and swing phase controlled knee joint

Abstract

Electronically controlled prosthetic knee joints have been introduced to meet ambulation demands of leg amputees. This study assessed whether microprocessor-controlled knee joints or non-electronically controlled knee joints are to be preferred regarding costs and functional health.

Thirteen participants with a unilateral knee/hip disarticulation or transfemoral amputation wore a prosthesis featuring a microprocessor-driven knee joint (C-group). Thirteen similar upper-leg amputees used a non-electronic knee joint (N-group).

Direct and indirect costs were established using a cost questionnaire, the PRODISQ, and database records of the Hoensbroeck Rehabilitation Centre. Intervention costs, health care costs, patients/family costs, productivity costs and total costs were calculated. Functional health was measured using the SF-36 (SF-6D).

Total costs averaged from € 39,350 (C-group) to € 46,086 (N-group). In the C-group intervention costs were 28.2% higher (p = 0.043) as were prosthetics costs (p = 0.000). Patients/family costs amounted to € 7,094 (C-group) and € 12,992 (N-group) (p = 0.053). In the N-group housekeeping assistance cost € 4,058 more (p = 0.007), and productivity loss was higher (p = 0.051). SF-6D scores and SF-36 sub-scores were higher in the C-group (p-values between 0.001 and 0.071).

Higher purchasing costs for prostheses with a microprocessor-controlled knee joint seem to be counterbalanced by lower costs in other domains. Functional health was clearly higher in the C-group.