Total knee replacement in juvenile rheumatoid arthritis

Comparison of therapeutic effects between drainage blood reinfusion and temporary clamping drainage after total knee arthroplasty in patients with rheumatoid arthritis

OBJECTIVE

To compare the therapeutic effects between drainage blood reinfusion and temporary clamping drainage after total knee arthroplasty in patients with rheumatoid arthritis to provide a basis for clinical practice.

METHODS

Data from 83 patients with rheumatoid arthritis undergoing total knee arthroplasty were retrospectively analyzed. The 83 patients were divided into a drainage blood reinfusion group (DR group, n = 45) and a temporary clamping drainage group (CD group, n = 38). In the DR group, postoperative drainage blood was used for autotransfusion. In the CD group, closed drainage was adopted, and the drainage tube was clamped for 2 h postoperatively followed by patency. The postoperative drainage amount, hemoglobin level, rate and average volume of allogeneic blood transfusion, swelling and ecchymosis of the affected knee joint, time to straight-leg raising and range of active knee flexion were compared between the two groups.

RESULTS

The total drainage volume was higher in the DR group than in the CD group (P = 0.000). The average volume of postoperative allogeneic blood transfusion (P = 0.000) and the decrease in the hemoglobin level 24 h after total knee arthroplasty (P = 0.012) were lower in the DR group than in the CD group. Swelling and ecchymosis of the affected knee joint, time to straight-leg raising and the range of active knee flexion were improved in the DR group compared with the CD group (all P<0.05).

CONCLUSION

Compared with temporary clamping drainage, drainage blood reinfusion after total knee arthroplasty can reduce the allogeneic blood transfusion volume and is conducive to early rehabilitation in patients with rheumatoid arthritis.

Biomechanical assessment of a patient-specific knee implant design using finite element method

Rheumatoid arthritis is the leading cause of disability in young adults. Total knee arthroplasty has been successfully used to restore the joint function. Due to small bone size, osteoporosis, and severe soft tissue disease, standard knee implant sometimes cannot be directly applied clinically and patient-specific designs may be a more rational choice. The purpose of this study was to evaluate the biomechanical behavior of a patient-specific knee implant. A three-dimensional finite element of total knee arthroplasty was developed. The mechanical strength and the wear damage of the articular surfaces were analyzed. The results show that there exist high risks of component fracture and wear damage; the proposed implant design should be abandoned. The presurgery analysis is helpful in avoiding the potential failure.