Comparison of the Clinical Outcomes after Total Knee Arthroplasty with the LCS Rotating Platform Mobile Bearing Knee System and the PFC Sigma RP-F Mobile Bearing Knee System

BACKGROUND: We compared clinical outcomes after total knee arthroplasty with the Low Contact Stress (LCS) rotating platform mobile bearing knee system and the Press Fit Condylar Sigma rotating platform high flexion (PFC Sigma RP-F) mobile bearing knee system. METHODS: Fifty cases of total knee arthroplasty were performed with the PFC Sigma RP-F mobile bearing knee system and sixty-one cases were performed with the LCS mobile bearing total knee arthroplasty. The average duration of follow-up was 2.9 years. RESULTS: The mean Hospital for Special Surgery (HSS) knee score was 62.1 (range, 52 to 75) in the LCS group and 61.9 (range, 50 to 74) in the Sigma RP-F group preoperatively, and 90.1 (range, 84 to 100) in the LCS group and 89.8 (range, 83 to 100) in the Sigma RP-F group at the final follow-up. The mean preoperative flexion contracture was 6.7degrees (range, 0degrees to 10degrees) in the LCS group and 9.3degrees (range, 0degrees to 15degrees) in the Sigma RP-F group preoperatively. The mean range of motion was 124.6degrees (range, 105degrees to 150degrees) in the LCS group and 126.1degrees (range, 104degrees to 145degrees) in the Sigma RP-F group at the final follow-up. CONCLUSIONS: After a minimum duration of follow-up of two years, we found no significant differences between the two groups with regard to the range of knee motion or the clinical or radiographic results.

A Case of Acute Orbital Abscess following Repair of Orbital wall Fracture with Alloplastic Implant

PURPOSE: To report a case of acute orbital abscess after Medpor(R) implantation for orbital floor fracture repair. CASE SUMMARY: A 15-year-old boy who was punched in the right orbit visited our clinic because of diplopia. An orbital CT scan demonstrated a fracture of the right orbital floor. At surgery, a Medpor sheet was placed over the orbital floor defect. Over the first three days, clinical improvement was gradual, but at four days postoperatively, depression of the right eye was restricted, and lower lid edema and proptosis was present in the right eye. At eight days postoperatively, the orbital CT scan showed a large cystic mass surrounding the Medpor sheet and fine needle aspiration cytology showed a number of inflammatory cells. Because systemic antibiotics were ineffective, the Medpo(R) sheet and the cystic mass were removed through a transconjunctival approach to the orbit. A culture of the removed Medpor(R) sheet grew Staphylococcus aureus and signs of inflammatory cells in the tissue were present. After removal of the abscess, most clinical symptoms showed improvement except for the remaining depression of the right eye. CONCLUSIONS: Symptoms of eye movement restriction, lower lid edema, and proptosis may be uncommon after orbital floor fracture repair but can occur. We should also consider the possibility of abscess formation due to infection of the implant and emphasize the importance of prompt diagnosis and treatment of such a case.