Background/Purpose: Preoperative patient expectations of Total Knee Arthroplasty (TKA) influence postoperative outcomes and satisfaction. Rheumatoid Arthritis (RA) may lower preoperative expectations after TKA compared to patients with knee osteoarthritis (OA). As RA patients undergoing primary TKA have lower expectations,  but comparable knee specific clinical outcomes when compared to OA patients we hypothesized that satisfaction would also be comparable. 

Methods: A retrospective review of 76 RA patients who underwent primary TKA from 2007-2011 were matched 1:2 with a cohort of 152 OA patients based on age, gender, ASA score, and Charlson Comorbidity Index score. The Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES), Visual Analogue Scale Pain (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS), and the Short Form-12 (SF-12) were compared at baseline and at two years post-op. Minimum Clinically Important Difference (MCID) was calculated for KOOS and SF-12 subdomains.

Results:   RA patients had significantly lower preoperative expectations (mean HSS-KRES 68.8 vs 77.7, p=0.03), higher VAS pain (66.2 vs 59.8, p=0.05), worse KOOS pain, knee symptoms, and activities of daily living limitations at baseline (p<0.01). At 2 years, the RA group had a larger improvement in VAS pain (-53.7 vs -44.8, p=0.02) and these 3 KOOS domains (p<0.05), achieving comparable scores to OA patients. RA patients had a significantly higher proportion of patients achieve MCID (11.96) for KOOS symptoms (98.4% vs 77.2%, p<0.001). There was no significant difference between satisfaction rates with over 85% of RA and OA patients either somewhat satisfied or very satisfied at 2 years follow-up.

Conclusion: While RA patients had lower baseline expectations compared to OA patients they achieved meaningful improvement in KOOS and SF-12 subdomains and there was no difference in satisfaction compared to OA patients after TKA. These findings may be used for preoperative counseling prior to TKA.