Page 44 - The value of total hip and knee arthroplasties for patients

Chapter 3
Patients with revision of a THA or TKA, those undergoing a hemiarthroplasty, and those undergoing a THA or TKA because of tumor or rheumatoid arthritis were excluded.
1 day preoperatively, before they were admitted to hospital, all eligible patients were given oral and written information concerning the study from the treating orthopaedic surgeon. Each patient was asked to return the set of questionnaires and the informed consent form when he or she was admitted the next day, the day of surgery. For the patients who did not want to participate, only age, sex, and the type of operation (THA or TKA) were recorded.
In cases where a patient who was already included in the study underwent another joint replacement during the study period, he or she was not included for a second time. 745 patients were admitted for THA and 614 patients were admitted for TKA from October 2010 through September 2012. Primary THA for primary OA was performed in 665 patients. Primary TKA for primary OA was performed in 599 patients.These 1,264 patients met all of the selection criteria and were asked to complete a questionnaire 1 day preoperatively. Of these, 302 THA and 271 TKA patients were included in the present study (Figure 1).
Sociodemographic and clinical characteristics
Sociodemographic characteristics (only preoperatively) included: age; sex; length (cm) and weight (kg), to calculate the body mass index; level of education (low: primary school, lower vocational education; medium: lower general secondary school, intermediate vocational education; or high: higher general secondary school, higher vocational education, university); and marital status (living alone—yes/no). In addition, it was asked whether patients had a paid job (yes/no). If not, they were asked to indicate if they were: a pensioner, a housewife/ houseman, or unemployed. For comorbidity, the self-reported Charnley classification (A–C) was used. Due to an error in the preoperative knee questionnaires, we were not able to determine the Charnley classification in the TKA group.
Patient-repor ted outcomes (PROMs) were used to describe the clinical characteristics at baseline.The hip disability and osteoarthritis outcome score (HOOS), the knee injury and osteoarthritis outcome score (KOOS), the Oxford hip score (OHS) and the Oxford knee score (OKS) were used for the preoperative and postoperative assessment of limitations (daily living, sport and recreation, function, and health- related quality of life). We used the validated Dutch versions of the HOOS, KOOS, OHS, and OKS.6-8
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