Measurement of clinical change caused by knee replacement. Conventional score or special change indexes?

Clinical change may be measured with specific indexes of change or with the difference between single-state examinations. Change scores and transition indexes are the special indexes of change analysed in this study. At the 10-year follow-up of compartmental replacements, the conformity between subsequent Hospital for Special Surgery overall scores and the patient's opinion of change from before knee replacement was 0.54. This was judged to be unacceptable. It is recommended that a transitional index be included in the clinical evaluation systems used for knee replacement.