Periarticular osteophyte formation protects against total knee arthroplasty in rheumatoid arthritis patients with advanced joint damage

Total knee arthroplasty in the past three decades: Trends in patient characteristics and implant survivorship

OBJECTIVE

To explore the trends in patient characteristics and implant survivorship (IS) for primary total knee arthroplasty (TKA) over the past three decades.

METHODS

This retrospective study enrolled a total of 635 knees who underwent TKA from 1985 to 2014. They were divided into three groups: group A, 125 knees in 1985-1994; group B, 203 knees in 1995-2004; and group C, 307 knees A in 2005-2014. The patient characteristics and IS were compared.

RESULTS

The mean age of patients undergoing TKA was getting older: 65.3 ± 9.7, 69.1 ± 10.0, and 74.6 ± 8.4 years, in groups A, B, and C, respectively (p = .001). The proportion of patients <60 years old with RA decreased (p < .001), whereas that of patients ≥ 80 years old with OA increased dramatically, it was 7.0%, 14.5%, and 32.0% in groups A, B, and C, respectively (p < .001). The IS free from infection was over 98% in all groups. Alternatively, the IS free from aseptic loosening become better, it was 83.7%, 95.2%, and 98.2% in groups A, B, and C, respectively (p = .014).

CONCLUSIONS

From these trends, we can estimate that the number of patients undergoing TKA will further increase in the future in an aging society.

Have the Radiographic Characteristics of Total Knee Arthroplasty Recipients in Rheumatoid Arthritis Changed After the Induction of Biologic Disease Modifying Anti-Rheumatic Drugs?

OBJECTIVES

Whether the characteristics of patients with rheumatoid arthritis (RA) undergoing total knee arthroplasty (TKA) have changed in the era of biologic disease-modifying antirheumatic drugs (bDMARDs) is unclear. We compared the radiographic findings of the knees in TKA recipients with RA before and after the introduction of bDMARDs.

METHODS

Consecutive patients who underwent primary TKA between 1999 and 2002 (115 knees; 79 patients, group A) and between 2013 and 2017 (117 knees; 95 patients, group B) were retrospectively evaluated. Clinical data, including disease duration, medication, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF), were collected. The Larsen classification, joint space narrowing (JSN), bone erosion, geode and osteophyte formation were evaluated on preoperative radiographs.

RESULTS

Osteophyte formation was significantly increased, and bone erosion and geode formation were significantly decreased in group B. In addition, medial-dominant JSN was significantly increased, and bicompartmental JSN was significantly decreased in group B. Medial-dominant JSN was positively, and bone erosion was negatively associated with osteophyte formation.

CONCLUSIONS

Following the introduction of bDMARDs, typical radiographic findings of rheumatoid knees have decreased, and secondary osteoarthritis (OA)-like changes, characterized by osteophyte formation and medial-dominant JSN, have increased in the knees of TKA recipients.