IMPORTANT VARIABLES AND THE SEVERITY OF PROBLEMS FOR PATIENTS UNDERGOING TOTAL KNEE ARTHROPLASTY AS MEASURED BY THE PATIENT SPECIFIC INDEX (PASI): A 24 MONTH FOLLOW-UP.

Abstract

The purpose of this study was to determine which activities are important to patients and to determine the severity of those problems. The five most important activities were walking outside, driving, walking indoors, stair climbing and daytime pain. Importance of these did not change postoperatively. The five most severe problems causing limitation were a limp, stiffness, loss of energy, daytime pain and locking. All these activities become statistically less severe over twenty-four months. Activities that are important to patients are different than the problems that are ranked by severity. Surgeons can educate patients that the severity of problems do improve over time following TKA.

The objectives of this study were:

1. to determine the five most important activities and five most severe problems for patients prior to total knee arthroplasty (TKA) using the Patient Specific Index (PASI) and

2. to determine the pattern of change in these activities over twenty-four months following TKA.

Activities that are most important to patients are different than problems that patients find severe. Important activities remain important over time. Severe problems become less severe over time.

Functional activities and PASI scores improve after TKA. Surgeons can educate patients that the problems they find most severe preoperatively do improve over time following TKA. Important activities remain important.

Patients scheduled for elective primary (or revision) TKA at two tertiary care teaching hospitals were enrolled in the study, excluding those not fluent in English and those undergoing TKA for a tumour, acute fracture, or an infection of the prosthesis. Patients completed the PASI pre-operatively, six, twelve and twenty-four months post-operatively.

One hundred and nineteen subjects were enrolled, nineteen were excluded. The five most important activities (ten- point scale, ten is most important) preoperatively were (mean; 95% CI): walking outside (6.25; 6.23–6.27), driving (6.17; 6.12–6.22), walking indoors (6.14; 6.12–6.16), climbing stairs (6.12; 6.10–6.14), and daytime pain (5.84; 5.81–5.87). These activities were not statistically less important over time. The most severe problems were limping (4.81; 4.77–4.85), stiffness (4.59; 4.56–4.62), lack of energy (4.51; 4.47–4.55), daytime pain (4.46; 4.43–3.39) and locking (4.38; 4.27–4.49). These were significantly less severe at twenty-four months (p < .001).