German short musculoskeletal function assessment questionnaire (SMFA-D): comparison with the SF-36 and WOMAC in a prospective evaluation in patients with primary osteoarthritis undergoing total knee arthroplasty. - Kirschner,S.; Walther,M.; Böhm,D.; Matzer,M.; Heesen,T.; Faller,H.; König,A. (Rheumatol Int, 2003)