Abstract
Introduction
Patient satisfaction after total hip arthroplasty (THA) has been reported to be significantly better than after total knee arthroplasty (TKA). The same has been observed for the capacity to forget during daily life activities about the operated joint. Recently a new patient reported outcome score, the Forgotten Joint Score (FJS-12) a twelve item questionaire, has been used to evaluate postoperative outcome in joint arthroplasty. A better FJS-12 score was measured in THA than in TKA objectivating the intuitive feeling that the joint was more forgotten in THA than in TKA.
Hypothesis
A higher preoperative FJS-12 score is the reason for a higher postoperative FJS-12 score in THA compared to TKA
Materials and methods
FJS-12 scores were prospectively collected in 75 THA and 75 TKA preoperatively and one year postoperative. Patients were stratified according to age and BMI. Effect size of treatment was calculated using the FJS-12.
Results
No preoperative difference in mean (SD) FJS-12 was observed for THA (24(17) versus TKA (22(15)). The mean (SD) postoperative FJS-12 was significantly higher for THA (79(25)) than for TKA (73(22)). Effect size of treatment was 3.4 for TKA and 3.2 for THA. Mean (SD) for men in THA (89(25)) was significantly higher than for men in TKA (74(22)).
Discussion
Postoperative differences in forgotten joint feeling after THA compared to TKA can not be explained by a preoperative difference. TKA is an effective surgery as measured by the effect size of treatment. Male TKA patients have worst outcome than male THA patients. This can probably be explained by mechanical or proprioceptive differences in between both types of arthroplasty.
