Joint awareness in osteoarthritis of the hip and knee evaluated with the 'Forgotten Joint' Score before and after joint replacement

Knee Surg Sports Traumatol Arthrosc. 2016 Oct;24(10):3346-3351. doi: 10.1007/s00167-015-3970-4. Epub 2016 Jan 6.


Purpose: To utilize the 'Forgotten Joint' Score (FJS), a 12-item questionnaire analysing the ability to forget the joint, for comparing preoperative status in osteoarthritic patients scheduled for total hip arthroplasty (THA) or total knee arthroplasty (TKA). Higher scores represent a better result with a maximum of 100. The hypothesis of this study was that a preoperative difference in favour of hip arthritis could eventually explain why THA is cited more often as a forgotten joint than TKA.

Methods: A prospective cohort study was conducted in 150 patients with either tricompartmental knee (n = 75) or hip osteoarthritis (n = 75). Patients completed FJS-12 scores preoperatively and 1 year postoperatively.

Results: A similar preoperative FJS-12 was observed for hip (22 (15)) and knee osteoarthritis (24 (17)) (n.s.). The postoperative FJS-12 score was significantly higher for THA (80 (24)) than for TKA (70 (27)) (p < 0.05). High reliability after 6 weeks was observed for the preoperative FJS-12 test-retest reliability (ICC = 0.87) in TKA. A preoperative floor effect of 15 % in THA and 0 % in TKA was found as well as a postoperative ceiling effect of 33 % in THA and 9 % in TKA.

Conclusions: The clinical relevance of utilizing the FJS-12 as an instrument to evaluate outcome is strongly proposed for knee arthroplasty. In general, one is not aware of a healthy joint during the ADL, and it can therefore be regarded as 'forgotten'. The preoperative FJS-12 Score is a powerful tool to provide patients with clearer insights into their positive evolution after surgery. The use of the FJS-12 in THA is a topic for further research, as this study found that floor and ceiling effects limit its usefulness in studies evaluating clinical outcome in this area.

Level of evidence: II.

Keywords: Forgotten Joint Score; Hip and knee arthritis; Patient-reported outcome; Total hip arthroplasty; Total knee arthroplasty.

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Hip*
  • Arthroplasty, Replacement, Knee*
  • Female
  • Hip Joint / surgery
  • Humans
  • Knee Joint / surgery
  • Male
  • Middle Aged
  • Osteoarthritis, Hip / diagnosis
  • Osteoarthritis, Hip / surgery*
  • Osteoarthritis, Knee / diagnosis
  • Osteoarthritis, Knee / surgery*
  • Patient Reported Outcome Measures*
  • Prospective Studies
  • Reproducibility of Results
  • Surveys and Questionnaires*
  • Treatment Outcome