Total joint replacement improves pain, functional quality of life, and health utilities in patients with late-stage knee and hip osteoarthritis for up to 5 years.

OBJECTIVES

To study and identify the determinants of the impact on pain, function, and quality of life of a prosthetic replacement surgery after 5 years of survival in patients with osteoarthritis (OA) of the lower limb.

METHOD

In total, 626 osteoarthritic patients from a University Hospital, divided in 2 groups (according to surgical site), were prospectively followed for 5 years after hip (n = 346) or knee (n = 280) replacement. Validated specific Western Ontario and McMaster Universities Arthritis Index (WOMAC) and generic (SF-36 and EQ) instruments assessing quality of life were used prior to surgery and yearly, thereafter. We defined a good outcome as a clinically relevant improvement in WOMAC greater than or equal to the minimally important difference (MID). Regressions showed the relationships among preoperative, perioperative, and postoperative measures and the evolution of WOMAC scores after 5 years (percent change). We also examined any predictors of good outcomes.

RESULTS

The beneficial effect on quality of life observed during the first year after hip and knee arthroplasty (HA and KA) was maintained for up to 5 years. More than 3/4 of the patients in our study experienced a good outcome (86.04% in HA group and 79.91% in KA group). Both the good outcome and the 5-year change in WOMAC are predicted by preoperative (i.e., radiological severity, comorbidities, disability, and level of education), perioperative (i.e., length of hospital stay and place of discharge), and postoperative (i.e., complications) variables in the two groups.

CONCLUSIONS

Joint arthroplasty is a highly valuable therapeutic strategy for hip or knee OA patients who do not respond to pharmacological management. These results represent a step towards the collection of robust, scientifically sound data that will facilitate the completion of health economic analyses in the field of OA.

KEY POINTS

• This study reports the long term outcomes of hip and knee replacement surgery in late-stage OA.• We identified pre-, per-, and post-operative determinants which contribute to a greater improvement in pain and function, hence increasing patients' satisfaction.• These results could contribute to select an OA population which has a high probability to get an optimal benefit from total joint replacement.