Benefits of using customized instrumentation in total knee arthroplasty: results from an activity-based costing model.

OBJECTIVE: The growing demand for total knee arthroplasty (TKA) associated with the efforts to contain healthcare expenditure by advanced economies necessitates the use of economically effective technologies in TKA. The present analysis based on activity-based costing (ABC) model was carried out to estimate the economic value of patient-matched instrumentation (PMI) compared to standard surgical instrumentation in TKA. METHODOLOGY: The costs of the two approaches, PMI and standard instrumentation in TKA, were determined by the use of ABC which measures the cost of a particular procedure by determining the activities involved and adding the cost of each activity. Improvement in productivity due to increased operating room (OR) turn-around times was determined and potential additional revenue to the hospital by the efficient utilization of gained OR time was estimated. RESULTS: Increased efficiency in the usage of OR and utilization of surgical trays were noted with patient-specific approach. Potential revenues to the hospital were estimated with the use of PMI by efficient utilization of time saved in OR. Additional revenues of 78,240 per year were estimated considering utilization of gained OR time to perform surgeries other than TKA. CONCLUSIONS: The analysis suggests that use of PMI in TKA is economically effective when compared to standard instrumentation.

Validity and reliability of accelerometer-based gait assessment in patients with diabetes on challenging surfaces.

Walking on irregular terrain influences gait of diabetic patients. We investigate the test-retest reliability and construct validity of gait measured with the DynaPort MiniMod under single and dual task conditions in diabetic patients walking on irregular terrain to identify the measurement error (precision) and minimal clinical detectable change. 29 patients with Type 2 diabetes were measured once, and 25 repeated the measurement within 7 days. Patients walked on a therapy garden walkway. Differences between three groups of diabetics with various levels of lower extremity neuropathy were analyzed with planned contrasts. ICC was excellent for intervisit measurements with ICC's >0.824. Bland and Altman Plots, SEM, and SDD showed precise values, distributed around zero for both test conditions. A significant effect of grouping on step length performance hints at possible construct validity of the device. Good reliability of DynaPort MiniMod measurements on a therapy garden walkway and an indication for discriminatory capability suggests that DynaPort MiniMod could facilitate the study of gait in diabetic patients in conditions close to real-life situations. Good reliability, small measurement error, and values of minimal clinical detectable change recommend the further utilization of DynaPort MiniMod for the evaluation of gait parameters in diabetic patients.