Analysis of perioperative clinical features and complications after orthopaedic surgery in rheumatoid arthritis patients treated with tocilizumab in a real-world setting: results from the multicentre TOcilizumab in Perioperative Period (TOPP) study.

OBJECTIVE: To evaluate perioperative changes in rheumatoid arthritis (RA) patients treated with tocilizumab. METHODS: We collected RA cases with tocilizumab and orthopaedic surgery from 1999 to 2010. Incidences of postoperative infections, delayed wound healing, and RA symptom flare-ups were extracted from the data for comparison with patients without these postoperative events. We also evaluated the changes in C-reactive protein (CRP) and body temperature in patients without postoperative complications with normal CRP before surgery, i.e., patients without postoperative events in whom the tocilizumab level was maintained, for each duration to discontinuation before surgery. RESULTS: A total of 161 cases (n = 122) were collected. The patients had mean age of 56.9 years, and mean disease duration of 12.8 years at operation. Joint replacement surgery was performed in 89 cases. Three patients had postoperative infections (two superficial and one organ/space surgical-site infection), 20 had delayed wound healing, and 36 had RA symptom flare-ups. Delayed wound healing occurred most commonly in patients who underwent spinal surgery (P = 0.0061, versus patients without delayed wound healing). CRP levels were high when tocilizumab was restarted in patients with RA symptom flare-ups (P = 0.0010, versus patients without RA symptom flare-ups). Increased postoperative CRP was observed in patients without postoperative events when the duration from final tocilizumab infusion to surgery was long. The changes in body temperature showed a similar trend to CRP. CONCLUSIONS: Although it has been demonstrated that infection rates in patients treated with tocilizumab are by no means high, incidence of delayed wound healing was significantly higher in cases with surgical interventions such as foot and spinal surgeries. Many patients treated with tocilizumab remained in a normal range of CRP even during the perioperative period. For prevention of perioperative complications, observation of postoperative conditions and surgical wounds, and subjective symptoms of patients are considered important.

Fluoroscopic and computed tomographic analysis of knee kinematics during very deep flexion after total knee arthroplasty.

We examined the relative motion of femoral and tibial total knee arthroplasty components and the difference between 2 different tibial inserts (9 flat types and 7 dish types) in patients sitting in very deep flexion. X-ray, fluoroscopic examination, and computed tomography were used to analyze liftoff, and rotation. During seiza-style sitting, one knee (11%) with the flat insert lifted off on the medial side and 5 knees (71%) with the dish-type insert showed liftoff. The tibial internal rotation angles were 17.2 degrees +/- 4.1 degrees (flat type) and 11.7 degrees +/- 3.1 degrees (dish type) (P < .05). The flat type showed less liftoff at the medial side and more internal rotation. For very deep flexion, components that tolerate larger rotational freedom are favorable.

A mechanical comparison of 2 posterior-stabilizing designs: Insall/Burstein 2 knee and Bisurface knee.

A posterior-stabilizing knee prosthesis, called the Bisurface knee (Kyocera Corp, Kyoto, Japan), with a ball-and-socket joint installed in the midposterior portion of the tibiofemoral joint, has been developed to satisfy 2 conflicting demands in knee joint design: kinematics and wear resistance. To confirm if the prosthesis has achieved its design objectives, a contact area and stress study was done throughout the range of motion and compared with results obtained for the Insall-Burstein 2 knee. The posterior-stabilizing ability of the ball-and-socket joint also was assessed. This study showed that the ball-and-socket joint could provide sufficient posterior stability, earlier start of flexion, and lower contact stress in the tibial polyethylene insert in flexion. The design of the Bisurface knee could provide a good balance between kinematics, stability, and wear resistance.